* [PATCH 01/13] switch befs long symlinks to page_symlink_operations
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 02/13] logfs: don't duplicate page_symlink_inode_operations Al Viro
` (12 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
just give them the right ->readpage()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/befs/linuxvfs.c | 41 ++++++++++++++++++++++-------------------
1 file changed, 22 insertions(+), 19 deletions(-)
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 46aedac..1c8b0dc 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -42,7 +42,7 @@ static struct inode *befs_iget(struct super_block *, unsigned long);
static struct inode *befs_alloc_inode(struct super_block *sb);
static void befs_destroy_inode(struct inode *inode);
static void befs_destroy_inodecache(void);
-static const char *befs_follow_link(struct dentry *, void **);
+static int befs_symlink_readpage(struct file *, struct page *);
static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
char **out, int *out_len);
static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
@@ -79,10 +79,8 @@ static const struct address_space_operations befs_aops = {
.bmap = befs_bmap,
};
-static const struct inode_operations befs_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = befs_follow_link,
- .put_link = kfree_put_link,
+static const struct address_space_operations befs_symlink_aops = {
+ .readpage = befs_symlink_readpage,
};
/*
@@ -398,7 +396,8 @@ static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
inode->i_fop = &befs_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
- inode->i_op = &befs_symlink_inode_operations;
+ inode->i_op = &page_symlink_inode_operations;
+ inode->i_mapping->a_ops = &befs_symlink_aops;
} else {
inode->i_link = befs_ino->i_data.symlink;
inode->i_op = &simple_symlink_inode_operations;
@@ -463,31 +462,35 @@ befs_destroy_inodecache(void)
* The data stream become link name. Unless the LONG_SYMLINK
* flag is set.
*/
-static const char *
-befs_follow_link(struct dentry *dentry, void **cookie)
+static int befs_symlink_readpage(struct file *unused, struct page *page)
{
- struct super_block *sb = dentry->d_sb;
- struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
+ struct inode *inode = page->mapping->host;
+ struct super_block *sb = inode->i_sb;
+ struct befs_inode_info *befs_ino = BEFS_I(inode);
befs_data_stream *data = &befs_ino->i_data.ds;
befs_off_t len = data->size;
- char *link;
+ char *link = kmap(page);
- if (len == 0) {
+ if (len == 0 || len > PAGE_SIZE) {
befs_error(sb, "Long symlink with illegal length");
- return ERR_PTR(-EIO);
+ goto fail;
}
befs_debug(sb, "Follow long symlink");
- link = kmalloc(len, GFP_NOFS);
- if (!link)
- return ERR_PTR(-ENOMEM);
if (befs_read_lsymlink(sb, data, link, len) != len) {
- kfree(link);
befs_error(sb, "Failed to read entire long symlink");
- return ERR_PTR(-EIO);
+ goto fail;
}
link[len - 1] = '\0';
- return *cookie = link;
+ SetPageUptodate(page);
+ kunmap(page);
+ unlock_page(page);
+ return 0;
+fail:
+ SetPageError(page);
+ kunmap(page);
+ unlock_page(page);
+ return -EIO;
}
/*
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 02/13] logfs: don't duplicate page_symlink_inode_operations
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
2016-01-01 6:38 ` [PATCH 01/13] switch befs long symlinks to page_symlink_operations Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 03/13] udf: " Al Viro
` (11 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/logfs/dir.c | 8 +-------
fs/logfs/inode.c | 2 +-
fs/logfs/logfs.h | 1 -
3 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index f9b45d4..99944a4 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -528,7 +528,7 @@ static int logfs_symlink(struct inode *dir, struct dentry *dentry,
if (IS_ERR(inode))
return PTR_ERR(inode);
- inode->i_op = &logfs_symlink_iops;
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &logfs_reg_aops;
return __logfs_create(dir, dentry, inode, target, destlen);
@@ -776,12 +776,6 @@ fail:
return -EIO;
}
-const struct inode_operations logfs_symlink_iops = {
- .readlink = generic_readlink,
- .follow_link = page_follow_link_light,
- .put_link = page_put_link,
-};
-
const struct inode_operations logfs_dir_iops = {
.create = logfs_create,
.link = logfs_link,
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index af49e2d..06baa92 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -64,7 +64,7 @@ static void logfs_inode_setops(struct inode *inode)
inode->i_mapping->a_ops = &logfs_reg_aops;
break;
case S_IFLNK:
- inode->i_op = &logfs_symlink_iops;
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &logfs_reg_aops;
break;
case S_IFSOCK: /* fall through */
diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
index 5f09376..209a26d 100644
--- a/fs/logfs/logfs.h
+++ b/fs/logfs/logfs.h
@@ -495,7 +495,6 @@ static inline int logfs_get_sb_mtd(struct logfs_super *s, int mtdnr)
#endif
/* dir.c */
-extern const struct inode_operations logfs_symlink_iops;
extern const struct inode_operations logfs_dir_iops;
extern const struct file_operations logfs_dir_fops;
int logfs_replay_journal(struct super_block *sb);
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 03/13] udf: don't duplicate page_symlink_inode_operations
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
2016-01-01 6:38 ` [PATCH 01/13] switch befs long symlinks to page_symlink_operations Al Viro
2016-01-01 6:38 ` [PATCH 02/13] logfs: don't duplicate page_symlink_inode_operations Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-05 16:27 ` Jan Kara
2016-01-01 6:38 ` [PATCH 04/13] ufs: get rid of ->setattr() for symlinks Al Viro
` (10 subsequent siblings)
13 siblings, 1 reply; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/udf/inode.c | 2 +-
fs/udf/namei.c | 7 +------
fs/udf/udfdecl.h | 1 -
3 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 8d0b3ad..8675c2b 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1540,7 +1540,7 @@ reread:
break;
case ICBTAG_FILE_TYPE_SYMLINK:
inode->i_data.a_ops = &udf_symlink_aops;
- inode->i_op = &udf_symlink_inode_operations;
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mode = S_IFLNK | S_IRWXUGO;
break;
case ICBTAG_FILE_TYPE_MAIN:
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index c97b5a8..d0e6de1 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -921,7 +921,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
}
inode->i_data.a_ops = &udf_symlink_aops;
- inode->i_op = &udf_symlink_inode_operations;
+ inode->i_op = &page_symlink_inode_operations;
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
struct kernel_lb_addr eloc;
@@ -1344,8 +1344,3 @@ const struct inode_operations udf_dir_inode_operations = {
.rename = udf_rename,
.tmpfile = udf_tmpfile,
};
-const struct inode_operations udf_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = page_follow_link_light,
- .put_link = page_put_link,
-};
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index 47bb3f5..ce169b4 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -85,7 +85,6 @@ extern const struct inode_operations udf_dir_inode_operations;
extern const struct file_operations udf_dir_operations;
extern const struct inode_operations udf_file_inode_operations;
extern const struct file_operations udf_file_operations;
-extern const struct inode_operations udf_symlink_inode_operations;
extern const struct address_space_operations udf_aops;
extern const struct address_space_operations udf_adinicb_aops;
extern const struct address_space_operations udf_symlink_aops;
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* Re: [PATCH 03/13] udf: don't duplicate page_symlink_inode_operations
2016-01-01 6:38 ` [PATCH 03/13] udf: " Al Viro
@ 2016-01-05 16:27 ` Jan Kara
0 siblings, 0 replies; 19+ messages in thread
From: Jan Kara @ 2016-01-05 16:27 UTC (permalink / raw)
To: Al Viro; +Cc: Linus Torvalds, linux-kernel, linux-fsdevel
On Fri 01-01-16 06:38:11, Al Viro wrote:
> From: Al Viro <viro@zeniv.linux.org.uk>
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Looks good. I guess it's more convenient for you to take this change
through your tree so:
Acked-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/udf/inode.c | 2 +-
> fs/udf/namei.c | 7 +------
> fs/udf/udfdecl.h | 1 -
> 3 files changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/fs/udf/inode.c b/fs/udf/inode.c
> index 8d0b3ad..8675c2b 100644
> --- a/fs/udf/inode.c
> +++ b/fs/udf/inode.c
> @@ -1540,7 +1540,7 @@ reread:
> break;
> case ICBTAG_FILE_TYPE_SYMLINK:
> inode->i_data.a_ops = &udf_symlink_aops;
> - inode->i_op = &udf_symlink_inode_operations;
> + inode->i_op = &page_symlink_inode_operations;
> inode->i_mode = S_IFLNK | S_IRWXUGO;
> break;
> case ICBTAG_FILE_TYPE_MAIN:
> diff --git a/fs/udf/namei.c b/fs/udf/namei.c
> index c97b5a8..d0e6de1 100644
> --- a/fs/udf/namei.c
> +++ b/fs/udf/namei.c
> @@ -921,7 +921,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
> }
>
> inode->i_data.a_ops = &udf_symlink_aops;
> - inode->i_op = &udf_symlink_inode_operations;
> + inode->i_op = &page_symlink_inode_operations;
>
> if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
> struct kernel_lb_addr eloc;
> @@ -1344,8 +1344,3 @@ const struct inode_operations udf_dir_inode_operations = {
> .rename = udf_rename,
> .tmpfile = udf_tmpfile,
> };
> -const struct inode_operations udf_symlink_inode_operations = {
> - .readlink = generic_readlink,
> - .follow_link = page_follow_link_light,
> - .put_link = page_put_link,
> -};
> diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
> index 47bb3f5..ce169b4 100644
> --- a/fs/udf/udfdecl.h
> +++ b/fs/udf/udfdecl.h
> @@ -85,7 +85,6 @@ extern const struct inode_operations udf_dir_inode_operations;
> extern const struct file_operations udf_dir_operations;
> extern const struct inode_operations udf_file_inode_operations;
> extern const struct file_operations udf_file_operations;
> -extern const struct inode_operations udf_symlink_inode_operations;
> extern const struct address_space_operations udf_aops;
> extern const struct address_space_operations udf_adinicb_aops;
> extern const struct address_space_operations udf_symlink_aops;
> --
> 2.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 04/13] ufs: get rid of ->setattr() for symlinks
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (2 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 03/13] udf: " Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 05/13] namei: page_getlink() and page_follow_link_light() are the same thing Al Viro
` (9 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
It was to needed for a couple of months in 2010, until UFS
quota support got dropped. Since then it's equivalent to
simple_setattr() (i.e. the default) for everything except the
regular files. And dropping it there allows to convert all
UFS symlinks to {page,simple}_symlink_inode_operations, getting
rid of fs/ufs/symlink.c completely.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ufs/Makefile | 2 +-
fs/ufs/inode.c | 4 ++--
fs/ufs/namei.c | 4 ++--
fs/ufs/symlink.c | 42 ------------------------------------------
fs/ufs/ufs.h | 4 ----
5 files changed, 5 insertions(+), 51 deletions(-)
delete mode 100644 fs/ufs/symlink.c
diff --git a/fs/ufs/Makefile b/fs/ufs/Makefile
index 392db25..ec4a6b4 100644
--- a/fs/ufs/Makefile
+++ b/fs/ufs/Makefile
@@ -5,5 +5,5 @@
obj-$(CONFIG_UFS_FS) += ufs.o
ufs-objs := balloc.o cylinder.o dir.o file.o ialloc.o inode.o \
- namei.o super.o symlink.o util.o
+ namei.o super.o util.o
ccflags-$(CONFIG_UFS_DEBUG) += -DDEBUG
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index a064cf44..737160a 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -528,11 +528,11 @@ static void ufs_set_inode_ops(struct inode *inode)
inode->i_mapping->a_ops = &ufs_aops;
} else if (S_ISLNK(inode->i_mode)) {
if (!inode->i_blocks) {
- inode->i_op = &ufs_fast_symlink_inode_operations;
inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
+ inode->i_op = &simple_symlink_inode_operations;
} else {
- inode->i_op = &ufs_symlink_inode_operations;
inode->i_mapping->a_ops = &ufs_aops;
+ inode->i_op = &page_symlink_inode_operations;
}
} else
init_special_inode(inode, inode->i_mode,
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 4796655..24b0cbd 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -123,14 +123,14 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry,
if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
/* slow symlink */
- inode->i_op = &ufs_symlink_inode_operations;
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &ufs_aops;
err = page_symlink(inode, symname, l);
if (err)
goto out_fail;
} else {
/* fast symlink */
- inode->i_op = &ufs_fast_symlink_inode_operations;
+ inode->i_op = &simple_symlink_inode_operations;
inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
memcpy(inode->i_link, symname, l);
inode->i_size = l-1;
diff --git a/fs/ufs/symlink.c b/fs/ufs/symlink.c
deleted file mode 100644
index 874480b..0000000
--- a/fs/ufs/symlink.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * linux/fs/ufs/symlink.c
- *
- * Only fast symlinks left here - the rest is done by generic code. AV, 1999
- *
- * Copyright (C) 1998
- * Daniel Pirkl <daniel.pirkl@emai.cz>
- * Charles University, Faculty of Mathematics and Physics
- *
- * from
- *
- * linux/fs/ext2/symlink.c
- *
- * Copyright (C) 1992, 1993, 1994, 1995
- * Remy Card (card@masi.ibp.fr)
- * Laboratoire MASI - Institut Blaise Pascal
- * Universite Pierre et Marie Curie (Paris VI)
- *
- * from
- *
- * linux/fs/minix/symlink.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * ext2 symlink handling code
- */
-
-#include "ufs_fs.h"
-#include "ufs.h"
-
-const struct inode_operations ufs_fast_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = simple_follow_link,
- .setattr = ufs_setattr,
-};
-
-const struct inode_operations ufs_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = page_follow_link_light,
- .put_link = page_put_link,
- .setattr = ufs_setattr,
-};
diff --git a/fs/ufs/ufs.h b/fs/ufs/ufs.h
index 7da4aca..c87f4c3 100644
--- a/fs/ufs/ufs.h
+++ b/fs/ufs/ufs.h
@@ -136,10 +136,6 @@ extern __printf(3, 4)
void ufs_panic(struct super_block *, const char *, const char *, ...);
void ufs_mark_sb_dirty(struct super_block *sb);
-/* symlink.c */
-extern const struct inode_operations ufs_fast_symlink_inode_operations;
-extern const struct inode_operations ufs_symlink_inode_operations;
-
static inline struct ufs_sb_info *UFS_SB(struct super_block *sb)
{
return sb->s_fs_info;
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 05/13] namei: page_getlink() and page_follow_link_light() are the same thing
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (3 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 04/13] ufs: get rid of ->setattr() for symlinks Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 06/13] don't put symlink bodies in pagecache into highmem Al Viro
` (8 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 32 +++++++++++++-------------------
1 file changed, 13 insertions(+), 19 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 0c3974c..4bae5cb 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4518,7 +4518,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
EXPORT_SYMBOL(generic_readlink);
/* get the link contents into pagecache */
-static char *page_getlink(struct dentry * dentry, struct page **ppage)
+static const char *page_getlink(struct dentry * dentry, void **cookie)
{
char *kaddr;
struct page *page;
@@ -4526,31 +4526,15 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage)
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
return (char*)page;
- *ppage = page;
+ *cookie = page;
kaddr = kmap(page);
nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
return kaddr;
}
-int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
-{
- struct page *page = NULL;
- int res = readlink_copy(buffer, buflen, page_getlink(dentry, &page));
- if (page) {
- kunmap(page);
- page_cache_release(page);
- }
- return res;
-}
-EXPORT_SYMBOL(page_readlink);
-
const char *page_follow_link_light(struct dentry *dentry, void **cookie)
{
- struct page *page = NULL;
- char *res = page_getlink(dentry, &page);
- if (!IS_ERR(res))
- *cookie = page;
- return res;
+ return page_getlink(dentry, cookie);
}
EXPORT_SYMBOL(page_follow_link_light);
@@ -4562,6 +4546,16 @@ void page_put_link(struct inode *unused, void *cookie)
}
EXPORT_SYMBOL(page_put_link);
+int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+ void *cookie = NULL;
+ int res = readlink_copy(buffer, buflen, page_getlink(dentry, &cookie));
+ if (cookie)
+ page_put_link(NULL, cookie);
+ return res;
+}
+EXPORT_SYMBOL(page_readlink);
+
/*
* The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS
*/
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 06/13] don't put symlink bodies in pagecache into highmem
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (4 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 05/13] namei: page_getlink() and page_follow_link_light() are the same thing Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 07/13] replace ->follow_link() with new method that could stay in RCU mode Al Viro
` (7 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
Documentation/filesystems/porting | 5 +++++
fs/affs/inode.c | 1 +
fs/affs/namei.c | 1 +
fs/affs/symlink.c | 4 +---
fs/afs/inode.c | 1 +
fs/befs/linuxvfs.c | 5 ++---
fs/btrfs/inode.c | 2 ++
fs/coda/cnode.c | 2 ++
fs/coda/symlink.c | 4 +---
fs/cramfs/inode.c | 1 +
fs/efs/inode.c | 1 +
fs/efs/symlink.c | 4 +---
fs/exofs/inode.c | 1 +
fs/exofs/namei.c | 1 +
fs/ext2/inode.c | 1 +
fs/ext2/namei.c | 1 +
fs/ext4/inode.c | 1 +
fs/ext4/namei.c | 1 +
fs/ext4/symlink.c | 10 +++-------
fs/f2fs/inode.c | 1 +
fs/f2fs/namei.c | 5 ++---
fs/freevxfs/vxfs_inode.c | 1 +
fs/hfsplus/inode.c | 2 ++
fs/hpfs/inode.c | 1 +
fs/hpfs/namei.c | 5 ++---
fs/hugetlbfs/inode.c | 1 +
fs/inode.c | 6 ++++++
fs/isofs/inode.c | 1 +
fs/isofs/rock.c | 4 +---
fs/jfs/inode.c | 1 +
fs/jfs/namei.c | 1 +
fs/logfs/dir.c | 1 +
fs/logfs/inode.c | 1 +
fs/minix/inode.c | 1 +
fs/namei.c | 9 +++------
fs/ncpfs/inode.c | 1 +
fs/nfs/inode.c | 5 +++--
fs/nfs/symlink.c | 2 +-
fs/nilfs2/inode.c | 1 +
fs/nilfs2/namei.c | 1 +
fs/ocfs2/inode.c | 1 +
fs/ocfs2/namei.c | 1 +
fs/qnx4/inode.c | 1 +
fs/qnx6/inode.c | 1 +
fs/ramfs/inode.c | 1 +
fs/reiserfs/inode.c | 1 +
fs/reiserfs/namei.c | 1 +
fs/romfs/super.c | 1 +
fs/squashfs/inode.c | 2 ++
fs/sysv/inode.c | 1 +
fs/udf/inode.c | 1 +
fs/udf/namei.c | 1 +
fs/udf/symlink.c | 4 +---
fs/ufs/inode.c | 1 +
fs/ufs/namei.c | 1 +
include/linux/fs.h | 1 +
mm/shmem.c | 9 +++------
57 files changed, 81 insertions(+), 46 deletions(-)
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index f24d1b8..3eb7c35 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -504,3 +504,8 @@ in your dentry operations instead.
[mandatory]
__fd_install() & fd_install() can now sleep. Callers should not
hold a spinlock or other resources that do not allow a schedule.
+--
+[mandatory]
+ any symlink that might use page_follow_link_light/page_put_link() must
+ have inode_nohighmem(inode) called before anything might start playing with
+ its pagecache.
diff --git a/fs/affs/inode.c b/fs/affs/inode.c
index 1734950..0fdb0f5 100644
--- a/fs/affs/inode.c
+++ b/fs/affs/inode.c
@@ -140,6 +140,7 @@ struct inode *affs_iget(struct super_block *sb, unsigned long ino)
break;
case ST_SOFTLINK:
inode->i_mode |= S_IFLNK;
+ inode_nohighmem(inode);
inode->i_op = &affs_symlink_inode_operations;
inode->i_data.a_ops = &affs_symlink_aops;
break;
diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index 181e05b..00d3002 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -344,6 +344,7 @@ affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
return -ENOSPC;
inode->i_op = &affs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &affs_symlink_aops;
inode->i_mode = S_IFLNK | 0777;
mode_to_prot(inode);
diff --git a/fs/affs/symlink.c b/fs/affs/symlink.c
index ea5b69a..e3f9dc3 100644
--- a/fs/affs/symlink.c
+++ b/fs/affs/symlink.c
@@ -14,7 +14,7 @@ static int affs_symlink_readpage(struct file *file, struct page *page)
{
struct buffer_head *bh;
struct inode *inode = page->mapping->host;
- char *link = kmap(page);
+ char *link = page_address(page);
struct slink_front *lf;
int i, j;
char c;
@@ -57,12 +57,10 @@ static int affs_symlink_readpage(struct file *file, struct page *page)
link[i] = '\0';
affs_brelse(bh);
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
fail:
SetPageError(page);
- kunmap(page);
unlock_page(page);
return -EIO;
}
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index e06f5a2..86cc726 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -56,6 +56,7 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
case AFS_FTYPE_SYMLINK:
inode->i_mode = S_IFLNK | vnode->status.mode;
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
break;
default:
printk("kAFS: AFS vnode with undefined type\n");
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 1c8b0dc..25250fa 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -397,6 +397,7 @@ static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
} else if (S_ISLNK(inode->i_mode)) {
if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &befs_symlink_aops;
} else {
inode->i_link = befs_ino->i_data.symlink;
@@ -469,7 +470,7 @@ static int befs_symlink_readpage(struct file *unused, struct page *page)
struct befs_inode_info *befs_ino = BEFS_I(inode);
befs_data_stream *data = &befs_ino->i_data.ds;
befs_off_t len = data->size;
- char *link = kmap(page);
+ char *link = page_address(page);
if (len == 0 || len > PAGE_SIZE) {
befs_error(sb, "Long symlink with illegal length");
@@ -483,12 +484,10 @@ static int befs_symlink_readpage(struct file *unused, struct page *page)
}
link[len - 1] = '\0';
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
fail:
SetPageError(page);
- kunmap(page);
unlock_page(page);
return -EIO;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a70c579..70f98bf 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3774,6 +3774,7 @@ cache_acl:
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_symlink_aops;
break;
default:
@@ -9705,6 +9706,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode_set_bytes(inode, name_len);
btrfs_i_size_write(inode, name_len);
diff --git a/fs/coda/cnode.c b/fs/coda/cnode.c
index 7740b1c..dd6a79e 100644
--- a/fs/coda/cnode.c
+++ b/fs/coda/cnode.c
@@ -8,6 +8,7 @@
#include <linux/coda.h>
#include <linux/coda_psdev.h>
+#include <linux/pagemap.h>
#include "coda_linux.h"
static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
@@ -35,6 +36,7 @@ static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
inode->i_fop = &coda_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &coda_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &coda_symlink_aops;
inode->i_mapping = &inode->i_data;
} else
diff --git a/fs/coda/symlink.c b/fs/coda/symlink.c
index ab94ef6..03736e2 100644
--- a/fs/coda/symlink.c
+++ b/fs/coda/symlink.c
@@ -26,7 +26,7 @@ static int coda_symlink_filler(struct file *file, struct page *page)
int error;
struct coda_inode_info *cii;
unsigned int len = PAGE_SIZE;
- char *p = kmap(page);
+ char *p = page_address(page);
cii = ITOC(inode);
@@ -34,13 +34,11 @@ static int coda_symlink_filler(struct file *file, struct page *page)
if (error)
goto fail;
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
fail:
SetPageError(page);
- kunmap(page);
unlock_page(page);
return error;
}
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 355c522..b862bc2 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -100,6 +100,7 @@ static struct inode *get_cramfs_inode(struct super_block *sb,
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &cramfs_aops;
break;
default:
diff --git a/fs/efs/inode.c b/fs/efs/inode.c
index 079d203..cdf0872 100644
--- a/fs/efs/inode.c
+++ b/fs/efs/inode.c
@@ -151,6 +151,7 @@ struct inode *efs_iget(struct super_block *super, unsigned long ino)
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &efs_symlink_aops;
break;
case S_IFCHR:
diff --git a/fs/efs/symlink.c b/fs/efs/symlink.c
index 75117d0..4870cc8 100644
--- a/fs/efs/symlink.c
+++ b/fs/efs/symlink.c
@@ -13,7 +13,7 @@
static int efs_symlink_readpage(struct file *file, struct page *page)
{
- char *link = kmap(page);
+ char *link = page_address(page);
struct buffer_head * bh;
struct inode * inode = page->mapping->host;
efs_block_t size = inode->i_size;
@@ -39,12 +39,10 @@ static int efs_symlink_readpage(struct file *file, struct page *page)
}
link[size] = '\0';
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
fail:
SetPageError(page);
- kunmap(page);
unlock_page(page);
return err;
}
diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
index 73c64da..d8e9c181 100644
--- a/fs/exofs/inode.c
+++ b/fs/exofs/inode.c
@@ -1227,6 +1227,7 @@ struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
inode->i_link = (char *)oi->i_data;
} else {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &exofs_aops;
}
} else {
diff --git a/fs/exofs/namei.c b/fs/exofs/namei.c
index 994e078..c20d77d 100644
--- a/fs/exofs/namei.c
+++ b/fs/exofs/namei.c
@@ -111,6 +111,7 @@ static int exofs_symlink(struct inode *dir, struct dentry *dentry,
if (l > sizeof(oi->i_data)) {
/* slow symlink */
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &exofs_aops;
memset(oi->i_data, 0, sizeof(oi->i_data));
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 0aa9bf6..338eefd 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1420,6 +1420,7 @@ struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
sizeof(ei->i_data) - 1);
} else {
inode->i_op = &ext2_symlink_inode_operations;
+ inode_nohighmem(inode);
if (test_opt(inode->i_sb, NOBH))
inode->i_mapping->a_ops = &ext2_nobh_aops;
else
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 3267a80d..7a2be8f 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -183,6 +183,7 @@ static int ext2_symlink (struct inode * dir, struct dentry * dentry,
if (l > sizeof (EXT2_I(inode)->i_data)) {
/* slow symlink */
inode->i_op = &ext2_symlink_inode_operations;
+ inode_nohighmem(inode);
if (test_opt(inode->i_sb, NOBH))
inode->i_mapping->a_ops = &ext2_nobh_aops;
else
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ea433a7..b3bd912 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4283,6 +4283,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
inode->i_op = &ext4_symlink_inode_operations;
ext4_set_aops(inode);
}
+ inode_nohighmem(inode);
} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
inode->i_op = &ext4_special_inode_operations;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a969ab3..f27e0c2 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3132,6 +3132,7 @@ static int ext4_symlink(struct inode *dir,
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
if (!encryption_required)
inode->i_op = &ext4_symlink_inode_operations;
+ inode_nohighmem(inode);
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index abe2401..0e6dc44 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -45,7 +45,7 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook
cpage = read_mapping_page(inode->i_mapping, 0, NULL);
if (IS_ERR(cpage))
return ERR_CAST(cpage);
- caddr = kmap(cpage);
+ caddr = page_address(cpage);
caddr[size] = 0;
}
@@ -75,16 +75,12 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook
/* Null-terminate the name */
if (res <= plen)
paddr[res] = '\0';
- if (cpage) {
- kunmap(cpage);
+ if (cpage)
page_cache_release(cpage);
- }
return *cookie = paddr;
errout:
- if (cpage) {
- kunmap(cpage);
+ if (cpage)
page_cache_release(cpage);
- }
kfree(paddr);
return ERR_PTR(res);
}
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 97e20de..5528801 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -202,6 +202,7 @@ make_now:
inode->i_op = &f2fs_encrypted_symlink_inode_operations;
else
inode->i_op = &f2fs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &f2fs_dblock_aops;
} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 2c32110..484df68 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -351,6 +351,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
inode->i_op = &f2fs_encrypted_symlink_inode_operations;
else
inode->i_op = &f2fs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &f2fs_dblock_aops;
f2fs_lock_op(sbi);
@@ -942,7 +943,7 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook
cpage = read_mapping_page(inode->i_mapping, 0, NULL);
if (IS_ERR(cpage))
return ERR_CAST(cpage);
- caddr = kmap(cpage);
+ caddr = page_address(cpage);
caddr[size] = 0;
/* Symlink is encrypted */
@@ -982,13 +983,11 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook
/* Null-terminate the name */
paddr[res] = '\0';
- kunmap(cpage);
page_cache_release(cpage);
return *cookie = paddr;
errout:
kfree(cstr.name);
f2fs_fname_crypto_free_buffer(&pstr);
- kunmap(cpage);
page_cache_release(cpage);
return ERR_PTR(res);
}
diff --git a/fs/freevxfs/vxfs_inode.c b/fs/freevxfs/vxfs_inode.c
index ef73ed6..3e2ccad 100644
--- a/fs/freevxfs/vxfs_inode.c
+++ b/fs/freevxfs/vxfs_inode.c
@@ -326,6 +326,7 @@ vxfs_iget(struct super_block *sbp, ino_t ino)
} else if (S_ISLNK(ip->i_mode)) {
if (!VXFS_ISIMMED(vip)) {
ip->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(ip);
ip->i_mapping->a_ops = &vxfs_aops;
} else {
ip->i_op = &simple_symlink_inode_operations;
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 6dd107d..19b33f8 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -403,6 +403,7 @@ struct inode *hfsplus_new_inode(struct super_block *sb, umode_t mode)
} else if (S_ISLNK(inode->i_mode)) {
sbi->file_count++;
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &hfsplus_aops;
hip->clump_blocks = 1;
} else
@@ -526,6 +527,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
inode->i_mapping->a_ops = &hfsplus_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &hfsplus_aops;
} else {
init_special_inode(inode, inode->i_mode,
diff --git a/fs/hpfs/inode.c b/fs/hpfs/inode.c
index 933c737..1f3c6d7 100644
--- a/fs/hpfs/inode.c
+++ b/fs/hpfs/inode.c
@@ -77,6 +77,7 @@ void hpfs_read_inode(struct inode *i)
kfree(ea);
i->i_mode = S_IFLNK | 0777;
i->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(i);
i->i_data.a_ops = &hpfs_symlink_aops;
set_nlink(i, 1);
i->i_size = ea_size;
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
index ae4d5a1..506765a 100644
--- a/fs/hpfs/namei.c
+++ b/fs/hpfs/namei.c
@@ -332,6 +332,7 @@ static int hpfs_symlink(struct inode *dir, struct dentry *dentry, const char *sy
result->i_blocks = 1;
set_nlink(result, 1);
result->i_size = strlen(symlink);
+ inode_nohighmem(result);
result->i_op = &page_symlink_inode_operations;
result->i_data.a_ops = &hpfs_symlink_aops;
@@ -500,7 +501,7 @@ out:
static int hpfs_symlink_readpage(struct file *file, struct page *page)
{
- char *link = kmap(page);
+ char *link = page_address(page);
struct inode *i = page->mapping->host;
struct fnode *fnode;
struct buffer_head *bh;
@@ -516,14 +517,12 @@ static int hpfs_symlink_readpage(struct file *file, struct page *page)
goto fail;
hpfs_unlock(i->i_sb);
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
fail:
hpfs_unlock(i->i_sb);
SetPageError(page);
- kunmap(page);
unlock_page(page);
return err;
}
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index de4bdfa..d8f51ee 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -760,6 +760,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
break;
}
lockdep_annotate_inode_mutex_key(inode);
diff --git a/fs/inode.c b/fs/inode.c
index 1be5f90..5bb85a0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2028,3 +2028,9 @@ void inode_set_flags(struct inode *inode, unsigned int flags,
new_flags) != old_flags));
}
EXPORT_SYMBOL(inode_set_flags);
+
+void inode_nohighmem(struct inode *inode)
+{
+ mapping_set_gfp_mask(inode->i_mapping, GFP_USER);
+}
+EXPORT_SYMBOL(inode_nohighmem);
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index d67a16f..61abdc4 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -1417,6 +1417,7 @@ static int isofs_read_inode(struct inode *inode, int relocated)
inode->i_fop = &isofs_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &isofs_symlink_aops;
} else
/* XXX - parse_rock_ridge_inode() had already set i_rdev. */
diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c
index 735d752..5384ceb 100644
--- a/fs/isofs/rock.c
+++ b/fs/isofs/rock.c
@@ -687,7 +687,7 @@ static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
struct inode *inode = page->mapping->host;
struct iso_inode_info *ei = ISOFS_I(inode);
struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
- char *link = kmap(page);
+ char *link = page_address(page);
unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
struct buffer_head *bh;
char *rpnt = link;
@@ -774,7 +774,6 @@ repeat:
brelse(bh);
*rpnt = '\0';
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
@@ -791,7 +790,6 @@ fail:
brelse(bh);
error:
SetPageError(page);
- kunmap(page);
unlock_page(page);
return -EIO;
}
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index 41aa3ca..9d9bae6 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -60,6 +60,7 @@ struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
} else if (S_ISLNK(inode->i_mode)) {
if (inode->i_size >= IDATASIZE) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &jfs_aops;
} else {
inode->i_op = &jfs_fast_symlink_inode_operations;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 9d7551f..701f893 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -983,6 +983,7 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
jfs_info("jfs_symlink: allocate extent ip:0x%p", ip);
ip->i_op = &jfs_symlink_inode_operations;
+ inode_nohighmem(ip);
ip->i_mapping->a_ops = &jfs_aops;
/*
diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 99944a4..542468e 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -529,6 +529,7 @@ static int logfs_symlink(struct inode *dir, struct dentry *dentry,
return PTR_ERR(inode);
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &logfs_reg_aops;
return __logfs_create(dir, dentry, inode, target, destlen);
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index 06baa92..0fce46d 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -65,6 +65,7 @@ static void logfs_inode_setops(struct inode *inode)
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &logfs_reg_aops;
break;
case S_IFSOCK: /* fall through */
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 086cd0a..67a23bf 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -452,6 +452,7 @@ void minix_set_inode(struct inode *inode, dev_t rdev)
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &minix_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &minix_aops;
} else
init_special_inode(inode, inode->i_mode, rdev);
diff --git a/fs/namei.c b/fs/namei.c
index 4bae5cb..2808958 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4527,7 +4527,8 @@ static const char *page_getlink(struct dentry * dentry, void **cookie)
if (IS_ERR(page))
return (char*)page;
*cookie = page;
- kaddr = kmap(page);
+ BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
+ kaddr = page_address(page);
nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
return kaddr;
}
@@ -4541,7 +4542,6 @@ EXPORT_SYMBOL(page_follow_link_light);
void page_put_link(struct inode *unused, void *cookie)
{
struct page *page = cookie;
- kunmap(page);
page_cache_release(page);
}
EXPORT_SYMBOL(page_put_link);
@@ -4565,7 +4565,6 @@ int __page_symlink(struct inode *inode, const char *symname, int len, int nofs)
struct page *page;
void *fsdata;
int err;
- char *kaddr;
unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE;
if (nofs)
flags |= AOP_FLAG_NOFS;
@@ -4576,9 +4575,7 @@ retry:
if (err)
goto fail;
- kaddr = kmap_atomic(page);
- memcpy(kaddr, symname, len-1);
- kunmap_atomic(kaddr);
+ memcpy(page_address(page), symname, len-1);
err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
page, fsdata);
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 9605a2f..bb856f7 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -283,6 +283,7 @@ ncp_iget(struct super_block *sb, struct ncp_entry_info *info)
#if defined(CONFIG_NCPFS_EXTRAS) || defined(CONFIG_NCPFS_NFS_NS)
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &ncp_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &ncp_symlink_aops;
#endif
} else {
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 31b0a52..ae9aa0b 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -408,9 +408,10 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, st
inode->i_fop = NULL;
inode->i_flags |= S_AUTOMOUNT;
}
- } else if (S_ISLNK(inode->i_mode))
+ } else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &nfs_symlink_inode_operations;
- else
+ inode_nohighmem(inode);
+ } else
init_special_inode(inode, inode->i_mode, fattr->rdev);
memset(&inode->i_atime, 0, sizeof(inode->i_atime));
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index b6de433..abd93bf 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -56,7 +56,7 @@ static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
if (IS_ERR(page))
return ERR_CAST(page);
*cookie = page;
- return kmap(page);
+ return page_address(page);
}
/*
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index ac2f649..10b2252 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -510,6 +510,7 @@ static int __nilfs_read_inode(struct super_block *sb,
inode->i_mapping->a_ops = &nilfs_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &nilfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &nilfs_aops;
} else {
inode->i_op = &nilfs_special_inode_operations;
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index c9a1a49..90b3ba9 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -161,6 +161,7 @@ static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
/* slow symlink */
inode->i_op = &nilfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &nilfs_aops;
err = page_symlink(inode, symname, l);
if (err)
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 8f87e05..97a563b 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -361,6 +361,7 @@ void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
break;
case S_IFLNK:
inode->i_op = &ocfs2_symlink_inode_operations;
+ inode_nohighmem(inode);
i_size_write(inode, le64_to_cpu(fe->i_size));
break;
default:
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index a03f6f4..2efe8af 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1960,6 +1960,7 @@ static int ocfs2_symlink(struct inode *dir,
inode->i_rdev = 0;
newsize = l - 1;
inode->i_op = &ocfs2_symlink_inode_operations;
+ inode_nohighmem(inode);
if (l > ocfs2_fast_symlink_chars(sb)) {
u32 offset = 0;
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index c4bcb77..f37b3de 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -316,6 +316,7 @@ struct inode *qnx4_iget(struct super_block *sb, unsigned long ino)
inode->i_fop = &qnx4_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &qnx4_aops;
qnx4_i(inode)->mmu_private = inode->i_size;
} else {
diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c
index 32d2e1a..9728b54 100644
--- a/fs/qnx6/inode.c
+++ b/fs/qnx6/inode.c
@@ -582,6 +582,7 @@ struct inode *qnx6_iget(struct super_block *sb, unsigned ino)
inode->i_mapping->a_ops = &qnx6_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &qnx6_aops;
} else
init_special_inode(inode, inode->i_mode, 0);
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 889d558..38981b0 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -79,6 +79,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
break;
}
}
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 3d8e7e6..ae9e5b3 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -1361,6 +1361,7 @@ static void init_inode(struct inode *inode, struct treepath *path)
inode->i_fop = &reiserfs_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &reiserfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &reiserfs_address_space_operations;
} else {
inode->i_blocks = 0;
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 47f9698..4fc2326 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -1170,6 +1170,7 @@ static int reiserfs_symlink(struct inode *parent_dir,
reiserfs_update_inode_transaction(parent_dir);
inode->i_op = &reiserfs_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &reiserfs_address_space_operations;
retval = reiserfs_add_entry(&th, parent_dir, dentry->d_name.name,
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 268733c..bb894e7 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -360,6 +360,7 @@ static struct inode *romfs_iget(struct super_block *sb, unsigned long pos)
break;
case ROMFH_SYM:
i->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(i);
i->i_data.a_ops = &romfs_aops;
mode |= S_IRWXUGO;
break;
diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c
index a1ce5ce..0927b1e 100644
--- a/fs/squashfs/inode.c
+++ b/fs/squashfs/inode.c
@@ -41,6 +41,7 @@
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/xattr.h>
+#include <linux/pagemap.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
@@ -291,6 +292,7 @@ int squashfs_read_inode(struct inode *inode, long long ino)
set_nlink(inode, le32_to_cpu(sqsh_ino->nlink));
inode->i_size = le32_to_cpu(sqsh_ino->symlink_size);
inode->i_op = &squashfs_symlink_inode_ops;
+ inode_nohighmem(inode);
inode->i_data.a_ops = &squashfs_symlink_aops;
inode->i_mode |= S_IFLNK;
squashfs_i(inode)->start = block;
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index 02fa1dc..ef8bcdb 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -163,6 +163,7 @@ void sysv_set_inode(struct inode *inode, dev_t rdev)
inode->i_mapping->a_ops = &sysv_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &sysv_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &sysv_aops;
} else
init_special_inode(inode, inode->i_mode, rdev);
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 8675c2b..0557463 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1541,6 +1541,7 @@ reread:
case ICBTAG_FILE_TYPE_SYMLINK:
inode->i_data.a_ops = &udf_symlink_aops;
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mode = S_IFLNK | S_IRWXUGO;
break;
case ICBTAG_FILE_TYPE_MAIN:
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index d0e6de1..42eafb9 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -922,6 +922,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
inode->i_data.a_ops = &udf_symlink_aops;
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
struct kernel_lb_addr eloc;
diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c
index 862535b..8d61977 100644
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -107,7 +107,7 @@ static int udf_symlink_filler(struct file *file, struct page *page)
struct buffer_head *bh = NULL;
unsigned char *symlink;
int err;
- unsigned char *p = kmap(page);
+ unsigned char *p = page_address(page);
struct udf_inode_info *iinfo;
uint32_t pos;
@@ -141,7 +141,6 @@ static int udf_symlink_filler(struct file *file, struct page *page)
up_read(&iinfo->i_data_sem);
SetPageUptodate(page);
- kunmap(page);
unlock_page(page);
return 0;
@@ -149,7 +148,6 @@ out_unlock_inode:
up_read(&iinfo->i_data_sem);
SetPageError(page);
out_unmap:
- kunmap(page);
unlock_page(page);
return err;
}
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 737160a..d897e16 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -533,6 +533,7 @@ static void ufs_set_inode_ops(struct inode *inode)
} else {
inode->i_mapping->a_ops = &ufs_aops;
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
}
} else
init_special_inode(inode, inode->i_mode,
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 24b0cbd..acf4a3b 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -124,6 +124,7 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry,
if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
/* slow symlink */
inode->i_op = &page_symlink_inode_operations;
+ inode_nohighmem(inode);
inode->i_mapping->a_ops = &ufs_aops;
err = page_symlink(inode, symname, l);
if (err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3aa5142..dfeda44 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3025,5 +3025,6 @@ static inline bool dir_relax(struct inode *inode)
}
extern bool path_noexec(const struct path *path);
+extern void inode_nohighmem(struct inode *inode);
#endif /* _LINUX_FS_H */
diff --git a/mm/shmem.c b/mm/shmem.c
index 9187eee..64bf5ac 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2444,7 +2444,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
int len;
struct inode *inode;
struct page *page;
- char *kaddr;
struct shmem_inode_info *info;
len = strlen(symname) + 1;
@@ -2483,9 +2482,8 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
}
inode->i_mapping->a_ops = &shmem_aops;
inode->i_op = &shmem_symlink_inode_operations;
- kaddr = kmap_atomic(page);
- memcpy(kaddr, symname, len);
- kunmap_atomic(kaddr);
+ inode_nohighmem(inode);
+ memcpy(page_address(page), symname, len);
SetPageUptodate(page);
set_page_dirty(page);
unlock_page(page);
@@ -2506,13 +2504,12 @@ static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
return ERR_PTR(error);
unlock_page(page);
*cookie = page;
- return kmap(page);
+ return page_address(page);
}
static void shmem_put_link(struct inode *unused, void *cookie)
{
struct page *page = cookie;
- kunmap(page);
mark_page_accessed(page);
page_cache_release(page);
}
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 07/13] replace ->follow_link() with new method that could stay in RCU mode
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (5 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 06/13] don't put symlink bodies in pagecache into highmem Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 08/13] teach page_get_link() to work " Al Viro
` (6 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
new method: ->get_link(); replacement of ->follow_link(). The differences
are:
* inode and dentry are passed separately
* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.
It's a flagday change - the old method is gone, all in-tree instances
converted. Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode. That'll change
in the next commits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
Documentation/filesystems/Locking | 4 +--
Documentation/filesystems/porting | 6 ++++
drivers/staging/lustre/lustre/llite/symlink.c | 8 +++--
fs/9p/vfs_inode.c | 17 +++++++---
fs/9p/vfs_inode_dotl.c | 14 ++++++---
fs/affs/symlink.c | 4 +--
fs/autofs4/symlink.c | 13 +++++---
fs/btrfs/inode.c | 2 +-
fs/ceph/inode.c | 2 +-
fs/cifs/cifsfs.c | 2 +-
fs/cifs/cifsfs.h | 4 +--
fs/cifs/link.c | 6 ++--
fs/coda/cnode.c | 2 +-
fs/configfs/symlink.c | 11 +++++--
fs/dcache.c | 2 +-
fs/ecryptfs/inode.c | 12 +++++--
fs/ext2/symlink.c | 4 +--
fs/ext4/symlink.c | 13 +++++---
fs/f2fs/namei.c | 16 ++++++----
fs/fuse/dir.c | 9 ++++--
fs/gfs2/inode.c | 15 ++++++---
fs/hostfs/hostfs_kern.c | 10 ++++--
fs/jffs2/symlink.c | 2 +-
fs/jfs/symlink.c | 4 +--
fs/kernfs/symlink.c | 11 +++++--
fs/libfs.c | 9 +++---
fs/minix/inode.c | 2 +-
fs/namei.c | 45 +++++++++++++++++----------
fs/ncpfs/inode.c | 2 +-
fs/nfs/symlink.c | 9 ++++--
fs/nilfs2/namei.c | 2 +-
fs/ocfs2/symlink.c | 2 +-
fs/overlayfs/inode.c | 12 ++++---
fs/proc/base.c | 22 +++++++------
fs/proc/inode.c | 7 +++--
fs/proc/namespaces.c | 9 ++++--
fs/proc/self.c | 9 ++++--
fs/proc/thread_self.c | 9 ++++--
fs/reiserfs/namei.c | 2 +-
fs/squashfs/symlink.c | 2 +-
fs/sysv/inode.c | 2 +-
fs/ubifs/file.c | 2 +-
fs/xfs/xfs_iops.c | 8 +++--
include/linux/fs.h | 6 ++--
mm/shmem.c | 12 ++++---
45 files changed, 234 insertions(+), 132 deletions(-)
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 06d4434..4fba54b 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -50,7 +50,7 @@ prototypes:
int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
- const char *(*follow_link) (struct dentry *, void **);
+ const char *(*get_link) (struct dentry *, struct inode *, void **);
void (*put_link) (struct inode *, void *);
void (*truncate) (struct inode *);
int (*permission) (struct inode *, int, unsigned int);
@@ -83,7 +83,7 @@ rmdir: yes (both) (see below)
rename: yes (all) (see below)
rename2: yes (all) (see below)
readlink: no
-follow_link: no
+get_link: no
put_link: no
setattr: yes
permission: no (may not block if called in rcu-walk mode)
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 3eb7c35..cf92a8c 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -509,3 +509,9 @@ in your dentry operations instead.
any symlink that might use page_follow_link_light/page_put_link() must
have inode_nohighmem(inode) called before anything might start playing with
its pagecache.
+--
+[mandatory]
+ ->follow_link() is replaced with ->get_link(); same API, except that
+ * ->get_link() gets inode as a separate argument
+ * ->get_link() may be called in RCU mode - in that case NULL
+ dentry is passed
diff --git a/drivers/staging/lustre/lustre/llite/symlink.c b/drivers/staging/lustre/lustre/llite/symlink.c
index 69b2036..153fdf9 100644
--- a/drivers/staging/lustre/lustre/llite/symlink.c
+++ b/drivers/staging/lustre/lustre/llite/symlink.c
@@ -118,12 +118,14 @@ failed:
return rc;
}
-static const char *ll_follow_link(struct dentry *dentry, void **cookie)
+static const char *ll_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(dentry);
struct ptlrpc_request *request = NULL;
int rc;
char *symname = NULL;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
CDEBUG(D_VFSTRACE, "VFS Op\n");
ll_inode_size_lock(inode);
@@ -149,7 +151,7 @@ static void ll_put_link(struct inode *unused, void *cookie)
struct inode_operations ll_fast_symlink_inode_operations = {
.readlink = generic_readlink,
.setattr = ll_setattr,
- .follow_link = ll_follow_link,
+ .get_link = ll_get_link,
.put_link = ll_put_link,
.getattr = ll_getattr,
.permission = ll_inode_permission,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 699941e..8ba5a89 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1223,18 +1223,25 @@ ino_t v9fs_qid2ino(struct p9_qid *qid)
}
/**
- * v9fs_vfs_follow_link - follow a symlink path
+ * v9fs_vfs_get_link - follow a symlink path
* @dentry: dentry for symlink
+ * @inode: inode for symlink
* @cookie: place to pass the data to put_link()
*/
-static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *v9fs_vfs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
- struct p9_fid *fid = v9fs_fid_lookup(dentry);
+ struct v9fs_session_info *v9ses;
+ struct p9_fid *fid;
struct p9_wstat *st;
char *res;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ v9ses = v9fs_dentry2v9ses(dentry);
+ fid = v9fs_fid_lookup(dentry);
p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
if (IS_ERR(fid))
@@ -1452,7 +1459,7 @@ static const struct inode_operations v9fs_file_inode_operations = {
static const struct inode_operations v9fs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = v9fs_vfs_follow_link,
+ .get_link = v9fs_vfs_get_link,
.put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index cb899af..0cc105d 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -899,20 +899,26 @@ error:
}
/**
- * v9fs_vfs_follow_link_dotl - follow a symlink path
+ * v9fs_vfs_get_link_dotl - follow a symlink path
* @dentry: dentry for symlink
+ * @inode: inode for symlink
* @cookie: place to pass the data to put_link()
*/
static const char *
-v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie)
+v9fs_vfs_get_link_dotl(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct p9_fid *fid = v9fs_fid_lookup(dentry);
+ struct p9_fid *fid;
char *target;
int retval;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
+ fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return ERR_CAST(fid);
retval = p9_client_readlink(fid, &target);
@@ -984,7 +990,7 @@ const struct inode_operations v9fs_file_inode_operations_dotl = {
const struct inode_operations v9fs_symlink_inode_operations_dotl = {
.readlink = generic_readlink,
- .follow_link = v9fs_vfs_follow_link_dotl,
+ .get_link = v9fs_vfs_get_link_dotl,
.put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr_dotl,
.setattr = v9fs_vfs_setattr_dotl,
diff --git a/fs/affs/symlink.c b/fs/affs/symlink.c
index e3f9dc3..39d1194 100644
--- a/fs/affs/symlink.c
+++ b/fs/affs/symlink.c
@@ -20,7 +20,7 @@ static int affs_symlink_readpage(struct file *file, struct page *page)
char c;
char lc;
- pr_debug("follow_link(ino=%lu)\n", inode->i_ino);
+ pr_debug("get_link(ino=%lu)\n", inode->i_ino);
bh = affs_bread(inode->i_sb, inode->i_ino);
if (!bh)
@@ -71,7 +71,7 @@ const struct address_space_operations affs_symlink_aops = {
const struct inode_operations affs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = affs_notify_change,
};
diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index da0c334..39e6f0b 100644
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -12,10 +12,15 @@
#include "autofs_i.h"
-static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
+static const char *autofs4_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
- struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct autofs_sb_info *sbi;
+ struct autofs_info *ino;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+ sbi = autofs4_sbi(dentry->d_sb);
+ ino = autofs4_dentry_ino(dentry);
if (ino && !autofs4_oz_mode(sbi))
ino->last_used = jiffies;
return d_inode(dentry)->i_private;
@@ -23,5 +28,5 @@ static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
const struct inode_operations autofs4_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = autofs4_follow_link
+ .get_link = autofs4_get_link
};
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 70f98bf..3d4aa69 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10096,7 +10096,7 @@ static const struct inode_operations btrfs_special_inode_operations = {
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 498dcfa..da55eb8 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1756,7 +1756,7 @@ retry:
*/
static const struct inode_operations ceph_symlink_iops = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = ceph_setattr,
.getattr = ceph_getattr,
.setxattr = ceph_setxattr,
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index cbc0f4b..4593f416 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -900,7 +900,7 @@ const struct inode_operations cifs_file_inode_ops = {
const struct inode_operations cifs_symlink_inode_ops = {
.readlink = generic_readlink,
- .follow_link = cifs_follow_link,
+ .get_link = cifs_get_link,
.put_link = kfree_put_link,
.permission = cifs_permission,
/* BB add the following two eventually */
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index c3cc160..6886328 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -120,9 +120,7 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
#endif
/* Functions related to symlinks */
-extern const char *cifs_follow_link(struct dentry *direntry, void **cookie);
-extern int cifs_readlink(struct dentry *direntry, char __user *buffer,
- int buflen);
+extern const char *cifs_get_link(struct dentry *, struct inode *, void **);
extern int cifs_symlink(struct inode *inode, struct dentry *direntry,
const char *symname);
extern int cifs_removexattr(struct dentry *, const char *);
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index e3548f7..6f2439b5 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -627,9 +627,8 @@ cifs_hl_exit:
}
const char *
-cifs_follow_link(struct dentry *direntry, void **cookie)
+cifs_get_link(struct dentry *direntry, struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(direntry);
int rc = -ENOMEM;
unsigned int xid;
char *full_path = NULL;
@@ -639,6 +638,9 @@ cifs_follow_link(struct dentry *direntry, void **cookie)
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
+ if (!direntry)
+ return ERR_PTR(-ECHILD);
+
xid = get_xid();
tlink = cifs_sb_tlink(cifs_sb);
diff --git a/fs/coda/cnode.c b/fs/coda/cnode.c
index dd6a79e..f18139c 100644
--- a/fs/coda/cnode.c
+++ b/fs/coda/cnode.c
@@ -18,7 +18,7 @@ static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
static const struct inode_operations coda_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = coda_setattr,
};
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index ec5c832..b91c01e 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -279,11 +279,16 @@ static int configfs_getlink(struct dentry *dentry, char * path)
}
-static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *configfs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- unsigned long page = get_zeroed_page(GFP_KERNEL);
+ unsigned long page;
int error;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ page = get_zeroed_page(GFP_KERNEL);
if (!page)
return ERR_PTR(-ENOMEM);
@@ -297,7 +302,7 @@ static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
}
const struct inode_operations configfs_symlink_inode_operations = {
- .follow_link = configfs_follow_link,
+ .get_link = configfs_get_link,
.readlink = generic_readlink,
.put_link = free_page_put_link,
.setattr = configfs_setattr,
diff --git a/fs/dcache.c b/fs/dcache.c
index 5c33aeb..d27f090 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1734,7 +1734,7 @@ static unsigned d_flags_for_inode(struct inode *inode)
}
if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) {
- if (unlikely(inode->i_op->follow_link)) {
+ if (unlikely(inode->i_op->get_link)) {
add_flags = DCACHE_SYMLINK_TYPE;
goto type_determined;
}
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index e2e47ba..5a05559 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -674,10 +674,16 @@ out:
return rc ? ERR_PTR(rc) : buf;
}
-static const char *ecryptfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *ecryptfs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
size_t len;
- char *buf = ecryptfs_readlink_lower(dentry, &len);
+ char *buf;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
+ buf = ecryptfs_readlink_lower(dentry, &len);
if (IS_ERR(buf))
return buf;
fsstack_copy_attr_atime(d_inode(dentry),
@@ -1095,7 +1101,7 @@ out:
const struct inode_operations ecryptfs_symlink_iops = {
.readlink = generic_readlink,
- .follow_link = ecryptfs_follow_link,
+ .get_link = ecryptfs_get_link,
.put_link = kfree_put_link,
.permission = ecryptfs_permission,
.setattr = ecryptfs_setattr,
diff --git a/fs/ext2/symlink.c b/fs/ext2/symlink.c
index ae17179..4690511 100644
--- a/fs/ext2/symlink.c
+++ b/fs/ext2/symlink.c
@@ -22,7 +22,7 @@
const struct inode_operations ext2_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = ext2_setattr,
#ifdef CONFIG_EXT2_FS_XATTR
@@ -35,7 +35,7 @@ const struct inode_operations ext2_symlink_inode_operations = {
const struct inode_operations ext2_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = ext2_setattr,
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 0e6dc44..3b4bfe2 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -23,17 +23,20 @@
#include "xattr.h"
#ifdef CONFIG_EXT4_FS_ENCRYPTION
-static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cookie)
+static const char *ext4_encrypted_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
struct ext4_str cstr, pstr;
- struct inode *inode = d_inode(dentry);
struct ext4_encrypted_symlink_data *sd;
loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
int res;
u32 plen, max_size = inode->i_sb->s_blocksize;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
res = ext4_get_encryption_info(inode);
if (res)
return ERR_PTR(res);
@@ -87,7 +90,7 @@ errout:
const struct inode_operations ext4_encrypted_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ext4_encrypted_follow_link,
+ .get_link = ext4_encrypted_get_link,
.put_link = kfree_put_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
@@ -99,7 +102,7 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
const struct inode_operations ext4_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
@@ -110,7 +113,7 @@ const struct inode_operations ext4_symlink_inode_operations = {
const struct inode_operations ext4_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 484df68..2a8d84b 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -315,9 +315,10 @@ fail:
return err;
}
-static const char *f2fs_follow_link(struct dentry *dentry, void **cookie)
+static const char *f2fs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- const char *link = page_follow_link_light(dentry, cookie);
+ const char *link = page_get_link(dentry, inode, cookie);
if (!IS_ERR(link) && !*link) {
/* this is broken symlink case */
page_put_link(NULL, *cookie);
@@ -924,18 +925,21 @@ static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
}
#ifdef CONFIG_F2FS_FS_ENCRYPTION
-static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cookie)
+static const char *f2fs_encrypted_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
struct f2fs_str cstr;
struct f2fs_str pstr = FSTR_INIT(NULL, 0);
- struct inode *inode = d_inode(dentry);
struct f2fs_encrypted_symlink_data *sd;
loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
u32 max_size = inode->i_sb->s_blocksize;
int res;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
res = f2fs_get_encryption_info(inode);
if (res)
return ERR_PTR(res);
@@ -994,7 +998,7 @@ errout:
const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = f2fs_encrypted_follow_link,
+ .get_link = f2fs_encrypted_get_link,
.put_link = kfree_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
@@ -1030,7 +1034,7 @@ const struct inode_operations f2fs_dir_inode_operations = {
const struct inode_operations f2fs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = f2fs_follow_link,
+ .get_link = f2fs_get_link,
.put_link = page_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 5e2e087..148e8ef 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1365,14 +1365,17 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
return err;
}
-static const char *fuse_follow_link(struct dentry *dentry, void **cookie)
+static const char *fuse_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(dentry);
struct fuse_conn *fc = get_fuse_conn(inode);
FUSE_ARGS(args);
char *link;
ssize_t ret;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
link = (char *) __get_free_page(GFP_KERNEL);
if (!link)
return ERR_PTR(-ENOMEM);
@@ -1909,7 +1912,7 @@ static const struct inode_operations fuse_common_inode_operations = {
static const struct inode_operations fuse_symlink_inode_operations = {
.setattr = fuse_setattr,
- .follow_link = fuse_follow_link,
+ .get_link = fuse_get_link,
.put_link = free_page_put_link,
.readlink = generic_readlink,
.getattr = fuse_getattr,
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 063fdfc..10950560 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1712,24 +1712,29 @@ static int gfs2_rename2(struct inode *odir, struct dentry *odentry,
}
/**
- * gfs2_follow_link - Follow a symbolic link
+ * gfs2_get_link - Follow a symbolic link
* @dentry: The dentry of the link
- * @nd: Data that we pass to vfs_follow_link()
+ * @inode: The inode of the link
+ * @cookie: place to store the information for ->put_link()
*
* This can handle symlinks of any size.
*
* Returns: 0 on success or error code
*/
-static const char *gfs2_follow_link(struct dentry *dentry, void **cookie)
+static const char *gfs2_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct gfs2_inode *ip = GFS2_I(d_inode(dentry));
+ struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder i_gh;
struct buffer_head *dibh;
unsigned int size;
char *buf;
int error;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
error = gfs2_glock_nq(&i_gh);
if (error) {
@@ -2132,7 +2137,7 @@ const struct inode_operations gfs2_dir_iops = {
const struct inode_operations gfs2_symlink_iops = {
.readlink = generic_readlink,
- .follow_link = gfs2_follow_link,
+ .get_link = gfs2_get_link,
.put_link = kfree_put_link,
.permission = gfs2_permission,
.setattr = gfs2_setattr,
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 2ac99db..6ce5309 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -892,9 +892,13 @@ static const struct inode_operations hostfs_dir_iops = {
.setattr = hostfs_setattr,
};
-static const char *hostfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *hostfs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- char *link = __getname();
+ char *link;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+ link = __getname();
if (link) {
char *path = dentry_name(dentry);
int err = -ENOMEM;
@@ -922,7 +926,7 @@ static void hostfs_put_link(struct inode *unused, void *cookie)
static const struct inode_operations hostfs_link_iops = {
.readlink = generic_readlink,
- .follow_link = hostfs_follow_link,
+ .get_link = hostfs_get_link,
.put_link = hostfs_put_link,
};
diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c
index 8ce2f24..2cabd64 100644
--- a/fs/jffs2/symlink.c
+++ b/fs/jffs2/symlink.c
@@ -14,7 +14,7 @@
const struct inode_operations jffs2_symlink_inode_operations =
{
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = jffs2_setattr,
.setxattr = jffs2_setxattr,
.getxattr = jffs2_getxattr,
diff --git a/fs/jfs/symlink.c b/fs/jfs/symlink.c
index 5929e23..0211328 100644
--- a/fs/jfs/symlink.c
+++ b/fs/jfs/symlink.c
@@ -23,7 +23,7 @@
const struct inode_operations jfs_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = jfs_setattr,
.setxattr = jfs_setxattr,
.getxattr = jfs_getxattr,
@@ -33,7 +33,7 @@ const struct inode_operations jfs_fast_symlink_inode_operations = {
const struct inode_operations jfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = jfs_setattr,
.setxattr = jfs_setxattr,
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index db27252..ffae857 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -112,10 +112,15 @@ static int kernfs_getlink(struct dentry *dentry, char *path)
return error;
}
-static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie)
+static const char *kernfs_iop_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
int error = -ENOMEM;
- unsigned long page = get_zeroed_page(GFP_KERNEL);
+ unsigned long page;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+ page = get_zeroed_page(GFP_KERNEL);
if (!page)
return ERR_PTR(-ENOMEM);
error = kernfs_getlink(dentry, (char *)page);
@@ -132,7 +137,7 @@ const struct inode_operations kernfs_symlink_iops = {
.getxattr = kernfs_iop_getxattr,
.listxattr = kernfs_iop_listxattr,
.readlink = generic_readlink,
- .follow_link = kernfs_iop_follow_link,
+ .get_link = kernfs_iop_get_link,
.put_link = free_page_put_link,
.setattr = kernfs_iop_setattr,
.getattr = kernfs_iop_getattr,
diff --git a/fs/libfs.c b/fs/libfs.c
index c7cbfb0..8dc37fc 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1092,14 +1092,15 @@ simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
}
EXPORT_SYMBOL(simple_nosetlease);
-const char *simple_follow_link(struct dentry *dentry, void **cookie)
+const char *simple_get_link(struct dentry *dentry, struct inode *inode,
+ void **cookie)
{
- return d_inode(dentry)->i_link;
+ return inode->i_link;
}
-EXPORT_SYMBOL(simple_follow_link);
+EXPORT_SYMBOL(simple_get_link);
const struct inode_operations simple_symlink_inode_operations = {
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.readlink = generic_readlink
};
EXPORT_SYMBOL(simple_symlink_inode_operations);
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 67a23bf..3cce709 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -435,7 +435,7 @@ static const struct address_space_operations minix_aops = {
static const struct inode_operations minix_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.getattr = minix_getattr,
};
diff --git a/fs/namei.c b/fs/namei.c
index 2808958..1da3064 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -842,7 +842,7 @@ static inline void path_to_nameidata(const struct path *path,
}
/*
- * Helper to directly jump to a known parsed path from ->follow_link,
+ * Helper to directly jump to a known parsed path from ->get_link,
* caller must have taken a reference to path beforehand.
*/
void nd_jump_link(struct path *path)
@@ -1005,10 +1005,18 @@ const char *get_link(struct nameidata *nd)
res = inode->i_link;
if (!res) {
if (nd->flags & LOOKUP_RCU) {
- if (unlikely(unlazy_walk(nd, NULL, 0)))
- return ERR_PTR(-ECHILD);
+ res = inode->i_op->get_link(NULL, inode,
+ &last->cookie);
+ if (res == ERR_PTR(-ECHILD)) {
+ if (unlikely(unlazy_walk(nd, NULL, 0)))
+ return ERR_PTR(-ECHILD);
+ res = inode->i_op->get_link(dentry, inode,
+ &last->cookie);
+ }
+ } else {
+ res = inode->i_op->get_link(dentry, inode,
+ &last->cookie);
}
- res = inode->i_op->follow_link(dentry, &last->cookie);
if (IS_ERR_OR_NULL(res)) {
last->cookie = NULL;
return res;
@@ -4495,8 +4503,8 @@ EXPORT_SYMBOL(readlink_copy);
/*
* A helper for ->readlink(). This should be used *ONLY* for symlinks that
- * have ->follow_link() touching nd only in nd_set_link(). Using (or not
- * using) it for any given inode is up to filesystem.
+ * have ->get_link() not calling nd_jump_link(). Using (or not using) it
+ * for any given inode is up to filesystem.
*/
int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
@@ -4506,7 +4514,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
int res;
if (!link) {
- link = inode->i_op->follow_link(dentry, &cookie);
+ link = inode->i_op->get_link(dentry, inode, &cookie);
if (IS_ERR(link))
return PTR_ERR(link);
}
@@ -4518,26 +4526,27 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
EXPORT_SYMBOL(generic_readlink);
/* get the link contents into pagecache */
-static const char *page_getlink(struct dentry * dentry, void **cookie)
+const char *page_get_link(struct dentry *dentry, struct inode *inode,
+ void **cookie)
{
char *kaddr;
struct page *page;
- struct address_space *mapping = dentry->d_inode->i_mapping;
+ struct address_space *mapping = inode->i_mapping;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
return (char*)page;
*cookie = page;
BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
kaddr = page_address(page);
- nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
+ nd_terminate_link(kaddr, inode->i_size, PAGE_SIZE - 1);
return kaddr;
}
-const char *page_follow_link_light(struct dentry *dentry, void **cookie)
-{
- return page_getlink(dentry, cookie);
-}
-EXPORT_SYMBOL(page_follow_link_light);
+EXPORT_SYMBOL(page_get_link);
void page_put_link(struct inode *unused, void *cookie)
{
@@ -4549,7 +4558,9 @@ EXPORT_SYMBOL(page_put_link);
int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
void *cookie = NULL;
- int res = readlink_copy(buffer, buflen, page_getlink(dentry, &cookie));
+ int res = readlink_copy(buffer, buflen,
+ page_get_link(dentry, d_inode(dentry),
+ &cookie));
if (cookie)
page_put_link(NULL, cookie);
return res;
@@ -4600,7 +4611,7 @@ EXPORT_SYMBOL(page_symlink);
const struct inode_operations page_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
};
EXPORT_SYMBOL(page_symlink_inode_operations);
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index bb856f7..3ab6cdb 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -244,7 +244,7 @@ static void ncp_set_attr(struct inode *inode, struct ncp_entry_info *nwinfo)
#if defined(CONFIG_NCPFS_EXTRAS) || defined(CONFIG_NCPFS_NFS_NS)
static const struct inode_operations ncp_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = ncp_notify_change,
};
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index abd93bf..8ade8a8 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -42,12 +42,15 @@ error:
return -EIO;
}
-static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *nfs_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(dentry);
struct page *page;
void *err;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
if (err)
return err;
@@ -64,7 +67,7 @@ static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
*/
const struct inode_operations nfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = nfs_follow_link,
+ .get_link = nfs_get_link,
.put_link = page_put_link,
.getattr = nfs_getattr,
.setattr = nfs_setattr,
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 90b3ba9..63dddb7 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -569,7 +569,7 @@ const struct inode_operations nilfs_special_inode_operations = {
const struct inode_operations nilfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.permission = nilfs_permission,
};
diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index 66edce7..b4e79bc 100644
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -88,7 +88,7 @@ const struct address_space_operations ocfs2_fast_symlink_aops = {
const struct inode_operations ocfs2_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.getattr = ocfs2_getattr,
.setattr = ocfs2_setattr,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4060ffd..38a0b8b 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -137,17 +137,21 @@ struct ovl_link_data {
void *cookie;
};
-static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
+static const char *ovl_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
struct dentry *realdentry;
struct inode *realinode;
struct ovl_link_data *data = NULL;
const char *ret;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
realdentry = ovl_dentry_real(dentry);
realinode = realdentry->d_inode;
- if (WARN_ON(!realinode->i_op->follow_link))
+ if (WARN_ON(!realinode->i_op->get_link))
return ERR_PTR(-EPERM);
if (realinode->i_op->put_link) {
@@ -157,7 +161,7 @@ static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
data->realdentry = realdentry;
}
- ret = realinode->i_op->follow_link(realdentry, cookie);
+ ret = realinode->i_op->get_link(realdentry, realinode, cookie);
if (IS_ERR_OR_NULL(ret)) {
kfree(data);
return ret;
@@ -378,7 +382,7 @@ static const struct inode_operations ovl_file_inode_operations = {
static const struct inode_operations ovl_symlink_inode_operations = {
.setattr = ovl_setattr,
- .follow_link = ovl_follow_link,
+ .get_link = ovl_get_link,
.put_link = ovl_put_link,
.readlink = ovl_readlink,
.getattr = ovl_getattr,
diff --git a/fs/proc/base.c b/fs/proc/base.c
index bd3e9e6..1a489e2 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1564,12 +1564,15 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
return -ENOENT;
}
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_pid_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(dentry);
struct path path;
int error = -EACCES;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
goto out;
@@ -1630,7 +1633,7 @@ out:
const struct inode_operations proc_pid_link_inode_operations = {
.readlink = proc_pid_readlink,
- .follow_link = proc_pid_follow_link,
+ .get_link = proc_pid_get_link,
.setattr = proc_setattr,
};
@@ -1895,7 +1898,7 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
.d_delete = pid_delete_dentry,
};
-static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path)
{
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
@@ -1945,20 +1948,21 @@ struct map_files_info {
* path to the file in question.
*/
static const char *
-proc_map_files_follow_link(struct dentry *dentry, void **cookie)
+proc_map_files_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
if (!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
- return proc_pid_follow_link(dentry, NULL);
+ return proc_pid_get_link(dentry, inode, NULL);
}
/*
- * Identical to proc_pid_link_inode_operations except for follow_link()
+ * Identical to proc_pid_link_inode_operations except for get_link()
*/
static const struct inode_operations proc_map_files_link_inode_operations = {
.readlink = proc_pid_readlink,
- .follow_link = proc_map_files_follow_link,
+ .get_link = proc_map_files_get_link,
.setattr = proc_setattr,
};
@@ -1975,7 +1979,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
return -ENOENT;
ei = PROC_I(inode);
- ei->op.proc_get_link = proc_map_files_get_link;
+ ei->op.proc_get_link = map_files_get_link;
inode->i_op = &proc_map_files_link_inode_operations;
inode->i_size = 64;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index bd95b9f..10360b2 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -393,9 +393,10 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
};
#endif
-static const char *proc_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct proc_dir_entry *pde = PDE(d_inode(dentry));
+ struct proc_dir_entry *pde = PDE(inode);
if (unlikely(!use_pde(pde)))
return ERR_PTR(-EINVAL);
*cookie = pde;
@@ -409,7 +410,7 @@ static void proc_put_link(struct inode *unused, void *p)
const struct inode_operations proc_link_inode_operations = {
.readlink = generic_readlink,
- .follow_link = proc_follow_link,
+ .get_link = proc_get_link,
.put_link = proc_put_link,
};
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index f6e8354..63861c1 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -30,14 +30,17 @@ static const struct proc_ns_operations *ns_entries[] = {
&mntns_operations,
};
-static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_ns_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct inode *inode = d_inode(dentry);
const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
struct path ns_path;
void *error = ERR_PTR(-EACCES);
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
task = get_proc_task(inode);
if (!task)
return error;
@@ -74,7 +77,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
static const struct inode_operations proc_ns_link_inode_operations = {
.readlink = proc_ns_readlink,
- .follow_link = proc_ns_follow_link,
+ .get_link = proc_ns_get_link,
.setattr = proc_setattr,
};
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 113b8d0..9dd0ae6 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -18,12 +18,15 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
return readlink_copy(buffer, buflen, tmp);
}
-static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_self_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+ struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
char *name;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
if (!tgid)
return ERR_PTR(-ENOENT);
/* 11 for max length of signed int in decimal + NULL term */
@@ -36,7 +39,7 @@ static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
static const struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
- .follow_link = proc_self_follow_link,
+ .get_link = proc_self_get_link,
.put_link = kfree_put_link,
};
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 947b0f4..50eef6f 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -19,13 +19,16 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
return readlink_copy(buffer, buflen, tmp);
}
-static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_thread_self_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
- struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+ struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
pid_t pid = task_pid_nr_ns(current, ns);
char *name;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
if (!pid)
return ERR_PTR(-ENOENT);
name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
@@ -37,7 +40,7 @@ static const char *proc_thread_self_follow_link(struct dentry *dentry, void **co
static const struct inode_operations proc_thread_self_inode_operations = {
.readlink = proc_thread_self_readlink,
- .follow_link = proc_thread_self_follow_link,
+ .get_link = proc_thread_self_get_link,
.put_link = kfree_put_link,
};
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 4fc2326..ecbf11e 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -1665,7 +1665,7 @@ const struct inode_operations reiserfs_dir_inode_operations = {
*/
const struct inode_operations reiserfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.setattr = reiserfs_setattr,
.setxattr = reiserfs_setxattr,
diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c
index 12806df..7c635a5 100644
--- a/fs/squashfs/symlink.c
+++ b/fs/squashfs/symlink.c
@@ -119,7 +119,7 @@ const struct address_space_operations squashfs_symlink_aops = {
const struct inode_operations squashfs_symlink_inode_ops = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.getxattr = generic_getxattr,
.listxattr = squashfs_listxattr
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index ef8bcdb..80a40bc 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -146,7 +146,7 @@ static inline void write3byte(struct sysv_sb_info *sbi,
static const struct inode_operations sysv_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = page_follow_link_light,
+ .get_link = page_get_link,
.put_link = page_put_link,
.getattr = sysv_getattr,
};
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 0edc128..eff6280 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1608,7 +1608,7 @@ const struct inode_operations ubifs_file_inode_operations = {
const struct inode_operations ubifs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
.setattr = ubifs_setattr,
.getattr = ubifs_getattr,
.setxattr = ubifs_setxattr,
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 245268a..f638fd5 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -414,13 +414,17 @@ xfs_vn_rename(
* uio is kmalloced for this reason...
*/
STATIC const char *
-xfs_vn_follow_link(
+xfs_vn_get_link(
struct dentry *dentry,
+ struct inode *inode,
void **cookie)
{
char *link;
int error = -ENOMEM;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
if (!link)
goto out_err;
@@ -1172,7 +1176,7 @@ static const struct inode_operations xfs_dir_ci_inode_operations = {
static const struct inode_operations xfs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = xfs_vn_follow_link,
+ .get_link = xfs_vn_get_link,
.put_link = kfree_put_link,
.getattr = xfs_vn_getattr,
.setattr = xfs_vn_setattr,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index dfeda44..d2fdf09 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1633,7 +1633,7 @@ struct file_operations {
struct inode_operations {
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
- const char * (*follow_link) (struct dentry *, void **);
+ const char * (*get_link) (struct dentry *, struct inode *, void **);
int (*permission) (struct inode *, int);
struct posix_acl * (*get_acl)(struct inode *, int);
@@ -2736,7 +2736,7 @@ extern const struct file_operations generic_ro_fops;
extern int readlink_copy(char __user *, int, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
-extern const char *page_follow_link_light(struct dentry *, void **);
+extern const char *page_get_link(struct dentry *, struct inode *, void **);
extern void page_put_link(struct inode *, void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
int nofs);
@@ -2754,7 +2754,7 @@ void __inode_sub_bytes(struct inode *inode, loff_t bytes);
void inode_sub_bytes(struct inode *inode, loff_t bytes);
loff_t inode_get_bytes(struct inode *inode);
void inode_set_bytes(struct inode *inode, loff_t bytes);
-const char *simple_follow_link(struct dentry *, void **);
+const char *simple_get_link(struct dentry *, struct inode *, void **);
extern const struct inode_operations simple_symlink_inode_operations;
extern int iterate_dir(struct file *, struct dir_context *);
diff --git a/mm/shmem.c b/mm/shmem.c
index 64bf5ac..684dbc3 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2496,10 +2496,14 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return 0;
}
-static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
+static const char *shmem_get_link(struct dentry *dentry,
+ struct inode *inode, void **cookie)
{
struct page *page = NULL;
- int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
+ int error;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+ error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
if (error)
return ERR_PTR(error);
unlock_page(page);
@@ -2656,7 +2660,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
@@ -2667,7 +2671,7 @@ static const struct inode_operations shmem_short_symlink_operations = {
static const struct inode_operations shmem_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = shmem_follow_link,
+ .get_link = shmem_get_link,
.put_link = shmem_put_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 08/13] teach page_get_link() to work in RCU mode
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (6 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 07/13] replace ->follow_link() with new method that could stay in RCU mode Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 09/13] teach shmem_get_link() " Al Viro
` (5 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
more or less along the lines of Neil's patchset, sans the insanity
around kmap().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 1da3064..8f51788 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4533,12 +4533,19 @@ const char *page_get_link(struct dentry *dentry, struct inode *inode,
struct page *page;
struct address_space *mapping = inode->i_mapping;
- if (!dentry)
- return ERR_PTR(-ECHILD);
-
- page = read_mapping_page(mapping, 0, NULL);
- if (IS_ERR(page))
- return (char*)page;
+ if (!dentry) {
+ page = find_get_page(mapping, 0);
+ if (!page)
+ return ERR_PTR(-ECHILD);
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-ECHILD);
+ }
+ } else {
+ page = read_mapping_page(mapping, 0, NULL);
+ if (IS_ERR(page))
+ return (char*)page;
+ }
*cookie = page;
BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
kaddr = page_address(page);
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 09/13] teach shmem_get_link() to work in RCU mode
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (7 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 08/13] teach page_get_link() to work " Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 10/13] teach proc_self_get_link()/proc_thread_self_get_link() " Al Viro
` (4 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
mm/shmem.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 684dbc3..0605716 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2501,12 +2501,20 @@ static const char *shmem_get_link(struct dentry *dentry,
{
struct page *page = NULL;
int error;
- if (!dentry)
- return ERR_PTR(-ECHILD);
- error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
- if (error)
- return ERR_PTR(error);
- unlock_page(page);
+ if (!dentry) {
+ page = find_get_page(inode->i_mapping, 0);
+ if (!page)
+ return ERR_PTR(-ECHILD);
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-ECHILD);
+ }
+ } else {
+ error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ }
*cookie = page;
return page_address(page);
}
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 10/13] teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (8 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 09/13] teach shmem_get_link() " Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 11/13] teach nfs_get_link() " Al Viro
` (3 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/proc/self.c | 8 +++-----
fs/proc/thread_self.c | 9 ++++-----
2 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 9dd0ae6..7a8b19e 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -25,14 +25,12 @@ static const char *proc_self_get_link(struct dentry *dentry,
pid_t tgid = task_tgid_nr_ns(current, ns);
char *name;
- if (!dentry)
- return ERR_PTR(-ECHILD);
if (!tgid)
return ERR_PTR(-ENOENT);
/* 11 for max length of signed int in decimal + NULL term */
- name = kmalloc(12, GFP_KERNEL);
- if (!name)
- return ERR_PTR(-ENOMEM);
+ name = kmalloc(12, dentry ? GFP_KERNEL : GFP_ATOMIC);
+ if (unlikely(!name))
+ return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d", tgid);
return *cookie = name;
}
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 50eef6f..03eaa84 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -27,13 +27,12 @@ static const char *proc_thread_self_get_link(struct dentry *dentry,
pid_t pid = task_pid_nr_ns(current, ns);
char *name;
- if (!dentry)
- return ERR_PTR(-ECHILD);
if (!pid)
return ERR_PTR(-ENOENT);
- name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
- if (!name)
- return ERR_PTR(-ENOMEM);
+ name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
+ dentry ? GFP_KERNEL : GFP_ATOMIC);
+ if (unlikely(!name))
+ return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d/task/%d", tgid, pid);
return *cookie = name;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 11/13] teach nfs_get_link() to work in RCU mode
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (9 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 10/13] teach proc_self_get_link()/proc_thread_self_get_link() " Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 12/13] kill free_page_put_link() Al Viro
` (2 subsequent siblings)
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
based upon the corresponding patch from Neil's March patchset,
again with kmap-related horrors removed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/nfs/inode.c | 21 +++++++++++++++++++++
fs/nfs/symlink.c | 30 ++++++++++++++++++++----------
include/linux/nfs_fs.h | 1 +
3 files changed, 42 insertions(+), 10 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ae9aa0b..aa828e8 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1087,6 +1087,27 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode)
|| NFS_STALE(inode);
}
+int nfs_revalidate_mapping_rcu(struct inode *inode)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ unsigned long *bitlock = &nfsi->flags;
+ int ret = 0;
+
+ if (IS_SWAPFILE(inode))
+ goto out;
+ if (nfs_mapping_need_revalidate_inode(inode)) {
+ ret = -ECHILD;
+ goto out;
+ }
+ spin_lock(&inode->i_lock);
+ if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
+ (nfsi->cache_validity & NFS_INO_INVALID_DATA))
+ ret = -ECHILD;
+ spin_unlock(&inode->i_lock);
+out:
+ return ret;
+}
+
/**
* __nfs_revalidate_mapping - Revalidate the pagecache
* @inode - pointer to host inode
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index 8ade8a8..95c69af 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -48,16 +48,26 @@ static const char *nfs_get_link(struct dentry *dentry,
struct page *page;
void *err;
- if (!dentry)
- return ERR_PTR(-ECHILD);
-
- err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
- if (err)
- return err;
- page = read_cache_page(&inode->i_data, 0,
- (filler_t *)nfs_symlink_filler, inode);
- if (IS_ERR(page))
- return ERR_CAST(page);
+ if (!dentry) {
+ err = ERR_PTR(nfs_revalidate_mapping_rcu(inode));
+ if (err)
+ return err;
+ page = find_get_page(inode->i_mapping, 0);
+ if (!page)
+ return ERR_PTR(-ECHILD);
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-ECHILD);
+ }
+ } else {
+ err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
+ if (err)
+ return err;
+ page = read_cache_page(&inode->i_data, 0,
+ (filler_t *)nfs_symlink_filler, inode);
+ if (IS_ERR(page))
+ return ERR_CAST(page);
+ }
*cookie = page;
return page_address(page);
}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index c0e9614..37a3d29 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -359,6 +359,7 @@ extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode);
extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
+extern int nfs_revalidate_mapping_rcu(struct inode *inode);
extern int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping);
extern int nfs_setattr(struct dentry *, struct iattr *);
extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 12/13] kill free_page_put_link()
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (10 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 11/13] teach nfs_get_link() " Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-01 6:38 ` [PATCH 13/13] switch ->get_link() to delayed_call, kill ->put_link() Al Viro
2016-01-03 19:53 ` [RFC] ->get_link(), ->put_link() and cookies Linus Torvalds
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
all callers are better off with kfree_put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/configfs/symlink.c | 12 ++++++------
fs/fuse/dir.c | 6 +++---
fs/kernfs/symlink.c | 12 ++++++------
fs/libfs.c | 6 ------
include/linux/fs.h | 1 -
5 files changed, 15 insertions(+), 22 deletions(-)
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index b91c01e..e9de962 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -282,29 +282,29 @@ static int configfs_getlink(struct dentry *dentry, char * path)
static const char *configfs_get_link(struct dentry *dentry,
struct inode *inode, void **cookie)
{
- unsigned long page;
+ char *page;
int error;
if (!dentry)
return ERR_PTR(-ECHILD);
- page = get_zeroed_page(GFP_KERNEL);
+ page = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!page)
return ERR_PTR(-ENOMEM);
- error = configfs_getlink(dentry, (char *)page);
+ error = configfs_getlink(dentry, page);
if (!error) {
- return *cookie = (void *)page;
+ return *cookie = page;
}
- free_page(page);
+ kfree(page);
return ERR_PTR(error);
}
const struct inode_operations configfs_symlink_inode_operations = {
.get_link = configfs_get_link,
.readlink = generic_readlink,
- .put_link = free_page_put_link,
+ .put_link = kfree_put_link,
.setattr = configfs_setattr,
};
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 148e8ef..def0a4d 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1376,7 +1376,7 @@ static const char *fuse_get_link(struct dentry *dentry,
if (!dentry)
return ERR_PTR(-ECHILD);
- link = (char *) __get_free_page(GFP_KERNEL);
+ link = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!link)
return ERR_PTR(-ENOMEM);
@@ -1388,7 +1388,7 @@ static const char *fuse_get_link(struct dentry *dentry,
args.out.args[0].value = link;
ret = fuse_simple_request(fc, &args);
if (ret < 0) {
- free_page((unsigned long) link);
+ kfree(link);
link = ERR_PTR(ret);
} else {
link[ret] = '\0';
@@ -1913,7 +1913,7 @@ static const struct inode_operations fuse_common_inode_operations = {
static const struct inode_operations fuse_symlink_inode_operations = {
.setattr = fuse_setattr,
.get_link = fuse_get_link,
- .put_link = free_page_put_link,
+ .put_link = kfree_put_link,
.readlink = generic_readlink,
.getattr = fuse_getattr,
.setxattr = fuse_setxattr,
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index ffae857..f9efdae 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -116,19 +116,19 @@ static const char *kernfs_iop_get_link(struct dentry *dentry,
struct inode *inode, void **cookie)
{
int error = -ENOMEM;
- unsigned long page;
+ char *page;
if (!dentry)
return ERR_PTR(-ECHILD);
- page = get_zeroed_page(GFP_KERNEL);
+ page = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!page)
return ERR_PTR(-ENOMEM);
- error = kernfs_getlink(dentry, (char *)page);
+ error = kernfs_getlink(dentry, page);
if (unlikely(error < 0)) {
- free_page((unsigned long)page);
+ kfree(page);
return ERR_PTR(error);
}
- return *cookie = (char *)page;
+ return *cookie = page;
}
const struct inode_operations kernfs_symlink_iops = {
@@ -138,7 +138,7 @@ const struct inode_operations kernfs_symlink_iops = {
.listxattr = kernfs_iop_listxattr,
.readlink = generic_readlink,
.get_link = kernfs_iop_get_link,
- .put_link = free_page_put_link,
+ .put_link = kfree_put_link,
.setattr = kernfs_iop_setattr,
.getattr = kernfs_iop_getattr,
.permission = kernfs_iop_permission,
diff --git a/fs/libfs.c b/fs/libfs.c
index 8dc37fc..fec7ab0 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1025,12 +1025,6 @@ void kfree_put_link(struct inode *unused, void *cookie)
}
EXPORT_SYMBOL(kfree_put_link);
-void free_page_put_link(struct inode *unused, void *cookie)
-{
- free_page((unsigned long) cookie);
-}
-EXPORT_SYMBOL(free_page_put_link);
-
/*
* nop .set_page_dirty method so that people can use .page_mkwrite on
* anon inodes.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d2fdf09..138e206 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2743,7 +2743,6 @@ extern int __page_symlink(struct inode *inode, const char *symname, int len,
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
extern void kfree_put_link(struct inode *, void *);
-extern void free_page_put_link(struct inode *, void *);
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* [PATCH 13/13] switch ->get_link() to delayed_call, kill ->put_link()
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (11 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 12/13] kill free_page_put_link() Al Viro
@ 2016-01-01 6:38 ` Al Viro
2016-01-03 19:53 ` [RFC] ->get_link(), ->put_link() and cookies Linus Torvalds
13 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-01 6:38 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, linux-fsdevel
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
Documentation/filesystems/Locking | 2 -
Documentation/filesystems/porting | 6 +++
Documentation/filesystems/vfs.txt | 21 +++++----
drivers/staging/lustre/lustre/llite/symlink.c | 18 ++++----
fs/9p/vfs_inode.c | 9 ++--
fs/9p/vfs_inode_dotl.c | 9 ++--
fs/affs/symlink.c | 1 -
fs/autofs4/symlink.c | 3 +-
fs/btrfs/inode.c | 1 -
fs/cifs/cifsfs.c | 1 -
fs/cifs/cifsfs.h | 3 +-
fs/cifs/link.c | 6 ++-
fs/coda/cnode.c | 1 -
fs/configfs/symlink.c | 17 ++++----
fs/ecryptfs/inode.c | 7 +--
fs/ext2/symlink.c | 1 -
fs/ext4/symlink.c | 8 ++--
fs/f2fs/namei.c | 16 ++++---
fs/fuse/dir.c | 6 +--
fs/gfs2/inode.c | 8 ++--
fs/hostfs/hostfs_kern.c | 16 +++----
fs/jfs/symlink.c | 1 -
fs/kernfs/symlink.c | 19 ++++----
fs/libfs.c | 9 ++--
fs/minix/inode.c | 1 -
fs/namei.c | 63 +++++++++++----------------
fs/ncpfs/inode.c | 1 -
fs/nfs/symlink.c | 6 +--
fs/nilfs2/namei.c | 1 -
fs/ocfs2/symlink.c | 1 -
fs/overlayfs/inode.c | 45 ++-----------------
fs/proc/base.c | 8 ++--
fs/proc/inode.c | 16 +++----
fs/proc/namespaces.c | 3 +-
fs/proc/self.c | 7 +--
fs/proc/thread_self.c | 7 +--
fs/reiserfs/namei.c | 1 -
fs/squashfs/symlink.c | 1 -
fs/sysv/inode.c | 1 -
fs/xfs/xfs_iops.c | 6 +--
include/linux/delayed_call.h | 34 +++++++++++++++
include/linux/fs.h | 14 +++---
mm/shmem.c | 19 ++++----
43 files changed, 206 insertions(+), 218 deletions(-)
create mode 100644 include/linux/delayed_call.h
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 4fba54b..619af9b 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -51,7 +51,6 @@ prototypes:
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
const char *(*get_link) (struct dentry *, struct inode *, void **);
- void (*put_link) (struct inode *, void *);
void (*truncate) (struct inode *);
int (*permission) (struct inode *, int, unsigned int);
int (*get_acl)(struct inode *, int);
@@ -84,7 +83,6 @@ rename: yes (all) (see below)
rename2: yes (all) (see below)
readlink: no
get_link: no
-put_link: no
setattr: yes
permission: no (may not block if called in rcu-walk mode)
get_acl: no
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index cf92a8c..0f88e60 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -515,3 +515,9 @@ in your dentry operations instead.
* ->get_link() gets inode as a separate argument
* ->get_link() may be called in RCU mode - in that case NULL
dentry is passed
+--
+[mandatory]
+ ->get_link() gets struct delayed_call *done now, and should do
+ set_delayed_call() where it used to set *cookie.
+ ->put_link() is gone - just give the destructor to set_delayed_call()
+ in ->get_link().
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 8c6f07a..b02a7d5 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -350,8 +350,8 @@ struct inode_operations {
int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
- const char *(*follow_link) (struct dentry *, void **);
- void (*put_link) (struct inode *, void *);
+ const char *(*get_link) (struct dentry *, struct inode *,
+ struct delayed_call *);
int (*permission) (struct inode *, int);
int (*get_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
@@ -434,20 +434,19 @@ otherwise noted.
readlink: called by the readlink(2) system call. Only required if
you want to support reading symbolic links
- follow_link: called by the VFS to follow a symbolic link to the
+ get_link: called by the VFS to follow a symbolic link to the
inode it points to. Only required if you want to support
symbolic links. This method returns the symlink body
to traverse (and possibly resets the current position with
nd_jump_link()). If the body won't go away until the inode
is gone, nothing else is needed; if it needs to be otherwise
- pinned, the data needed to release whatever we'd grabbed
- is to be stored in void * variable passed by address to
- follow_link() instance.
-
- put_link: called by the VFS to release resources allocated by
- follow_link(). The cookie stored by follow_link() is passed
- to this method as the last parameter; only called when
- cookie isn't NULL.
+ pinned, arrange for its release by having get_link(..., ..., done)
+ do set_delayed_call(done, destructor, argument).
+ In that case destructor(argument) will be called once VFS is
+ done with the body you've returned.
+ May be called in RCU mode; that is indicated by NULL dentry
+ argument. If request can't be handled without leaving RCU mode,
+ have it return ERR_PTR(-ECHILD).
permission: called by the VFS to check for access rights on a POSIX-like
filesystem.
diff --git a/drivers/staging/lustre/lustre/llite/symlink.c b/drivers/staging/lustre/lustre/llite/symlink.c
index 153fdf9..e489a32 100644
--- a/drivers/staging/lustre/lustre/llite/symlink.c
+++ b/drivers/staging/lustre/lustre/llite/symlink.c
@@ -118,8 +118,14 @@ failed:
return rc;
}
+static void ll_put_link(void *p)
+{
+ ptlrpc_req_finished(p);
+}
+
static const char *ll_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct ptlrpc_request *request = NULL;
int rc;
@@ -137,22 +143,16 @@ static const char *ll_get_link(struct dentry *dentry,
}
/* symname may contain a pointer to the request message buffer,
- * we delay request releasing until ll_put_link then.
+ * we delay request releasing then.
*/
- *cookie = request;
+ set_delayed_call(done, ll_put_link, request);
return symname;
}
-static void ll_put_link(struct inode *unused, void *cookie)
-{
- ptlrpc_req_finished(cookie);
-}
-
struct inode_operations ll_fast_symlink_inode_operations = {
.readlink = generic_readlink,
.setattr = ll_setattr,
.get_link = ll_get_link,
- .put_link = ll_put_link,
.getattr = ll_getattr,
.permission = ll_inode_permission,
.setxattr = ll_setxattr,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 8ba5a89..f928f87 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1226,11 +1226,12 @@ ino_t v9fs_qid2ino(struct p9_qid *qid)
* v9fs_vfs_get_link - follow a symlink path
* @dentry: dentry for symlink
* @inode: inode for symlink
- * @cookie: place to pass the data to put_link()
+ * @done: delayed call for when we are done with the return value
*/
static const char *v9fs_vfs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
@@ -1266,7 +1267,8 @@ static const char *v9fs_vfs_get_link(struct dentry *dentry,
p9stat_free(st);
kfree(st);
- return *cookie = res;
+ set_delayed_call(done, kfree_link, res);
+ return res;
}
/**
@@ -1460,7 +1462,6 @@ static const struct inode_operations v9fs_file_inode_operations = {
static const struct inode_operations v9fs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = v9fs_vfs_get_link,
- .put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 0cc105d..a34702c 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -902,12 +902,13 @@ error:
* v9fs_vfs_get_link_dotl - follow a symlink path
* @dentry: dentry for symlink
* @inode: inode for symlink
- * @cookie: place to pass the data to put_link()
+ * @done: destructor for return value
*/
static const char *
v9fs_vfs_get_link_dotl(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct p9_fid *fid;
char *target;
@@ -924,7 +925,8 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry,
retval = p9_client_readlink(fid, &target);
if (retval)
return ERR_PTR(retval);
- return *cookie = target;
+ set_delayed_call(done, kfree_link, target);
+ return target;
}
int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
@@ -991,7 +993,6 @@ const struct inode_operations v9fs_file_inode_operations_dotl = {
const struct inode_operations v9fs_symlink_inode_operations_dotl = {
.readlink = generic_readlink,
.get_link = v9fs_vfs_get_link_dotl,
- .put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr_dotl,
.setattr = v9fs_vfs_setattr_dotl,
.setxattr = generic_setxattr,
diff --git a/fs/affs/symlink.c b/fs/affs/symlink.c
index 39d1194..69b03db 100644
--- a/fs/affs/symlink.c
+++ b/fs/affs/symlink.c
@@ -72,6 +72,5 @@ const struct address_space_operations affs_symlink_aops = {
const struct inode_operations affs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = affs_notify_change,
};
diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index 39e6f0b..84e037d 100644
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -13,7 +13,8 @@
#include "autofs_i.h"
static const char *autofs4_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3d4aa69..1a41a65 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10097,7 +10097,6 @@ static const struct inode_operations btrfs_special_inode_operations = {
static const struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 4593f416..90e4e2b 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -901,7 +901,6 @@ const struct inode_operations cifs_file_inode_ops = {
const struct inode_operations cifs_symlink_inode_ops = {
.readlink = generic_readlink,
.get_link = cifs_get_link,
- .put_link = kfree_put_link,
.permission = cifs_permission,
/* BB add the following two eventually */
/* revalidate: cifs_revalidate,
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 6886328..26a1187 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -120,7 +120,8 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
#endif
/* Functions related to symlinks */
-extern const char *cifs_get_link(struct dentry *, struct inode *, void **);
+extern const char *cifs_get_link(struct dentry *, struct inode *,
+ struct delayed_call *);
extern int cifs_symlink(struct inode *inode, struct dentry *direntry,
const char *symname);
extern int cifs_removexattr(struct dentry *, const char *);
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 6f2439b5..062c237 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -627,7 +627,8 @@ cifs_hl_exit:
}
const char *
-cifs_get_link(struct dentry *direntry, struct inode *inode, void **cookie)
+cifs_get_link(struct dentry *direntry, struct inode *inode,
+ struct delayed_call *done)
{
int rc = -ENOMEM;
unsigned int xid;
@@ -680,7 +681,8 @@ cifs_get_link(struct dentry *direntry, struct inode *inode, void **cookie)
kfree(target_path);
return ERR_PTR(rc);
}
- return *cookie = target_path;
+ set_delayed_call(done, kfree_link, target_path);
+ return target_path;
}
int
diff --git a/fs/coda/cnode.c b/fs/coda/cnode.c
index f18139c..1bfb7ba 100644
--- a/fs/coda/cnode.c
+++ b/fs/coda/cnode.c
@@ -19,7 +19,6 @@ static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
static const struct inode_operations coda_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = coda_setattr,
};
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index e9de962..db6d692 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -280,31 +280,32 @@ static int configfs_getlink(struct dentry *dentry, char * path)
}
static const char *configfs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
- char *page;
+ char *body;
int error;
if (!dentry)
return ERR_PTR(-ECHILD);
- page = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!page)
+ body = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!body)
return ERR_PTR(-ENOMEM);
- error = configfs_getlink(dentry, page);
+ error = configfs_getlink(dentry, body);
if (!error) {
- return *cookie = page;
+ set_delayed_call(done, kfree_link, body);
+ return body;
}
- kfree(page);
+ kfree(body);
return ERR_PTR(error);
}
const struct inode_operations configfs_symlink_inode_operations = {
.get_link = configfs_get_link,
.readlink = generic_readlink,
- .put_link = kfree_put_link,
.setattr = configfs_setattr,
};
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5a05559..a4dddc61 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -675,7 +675,8 @@ out:
}
static const char *ecryptfs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
size_t len;
char *buf;
@@ -689,7 +690,8 @@ static const char *ecryptfs_get_link(struct dentry *dentry,
fsstack_copy_attr_atime(d_inode(dentry),
d_inode(ecryptfs_dentry_to_lower(dentry)));
buf[len] = '\0';
- return *cookie = buf;
+ set_delayed_call(done, kfree_link, buf);
+ return buf;
}
/**
@@ -1102,7 +1104,6 @@ out:
const struct inode_operations ecryptfs_symlink_iops = {
.readlink = generic_readlink,
.get_link = ecryptfs_get_link,
- .put_link = kfree_put_link,
.permission = ecryptfs_permission,
.setattr = ecryptfs_setattr,
.getattr = ecryptfs_getattr_link,
diff --git a/fs/ext2/symlink.c b/fs/ext2/symlink.c
index 4690511..3495d8a 100644
--- a/fs/ext2/symlink.c
+++ b/fs/ext2/symlink.c
@@ -23,7 +23,6 @@
const struct inode_operations ext2_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = ext2_setattr,
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 3b4bfe2..2281ac2 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -24,7 +24,8 @@
#ifdef CONFIG_EXT4_FS_ENCRYPTION
static const char *ext4_encrypted_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
@@ -80,7 +81,8 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
paddr[res] = '\0';
if (cpage)
page_cache_release(cpage);
- return *cookie = paddr;
+ set_delayed_call(done, kfree_link, paddr);
+ return paddr;
errout:
if (cpage)
page_cache_release(cpage);
@@ -91,7 +93,6 @@ errout:
const struct inode_operations ext4_encrypted_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = ext4_encrypted_get_link,
- .put_link = kfree_put_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
@@ -103,7 +104,6 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
const struct inode_operations ext4_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 2a8d84b..e7587fc 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -316,12 +316,14 @@ fail:
}
static const char *f2fs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
- const char *link = page_get_link(dentry, inode, cookie);
+ const char *link = page_get_link(dentry, inode, done);
if (!IS_ERR(link) && !*link) {
/* this is broken symlink case */
- page_put_link(NULL, *cookie);
+ do_delayed_call(done);
+ clear_delayed_call(done);
link = ERR_PTR(-ENOENT);
}
return link;
@@ -926,7 +928,8 @@ static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
#ifdef CONFIG_F2FS_FS_ENCRYPTION
static const char *f2fs_encrypted_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
@@ -988,7 +991,8 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
paddr[res] = '\0';
page_cache_release(cpage);
- return *cookie = paddr;
+ set_delayed_call(done, kfree_link, paddr);
+ return paddr;
errout:
kfree(cstr.name);
f2fs_fname_crypto_free_buffer(&pstr);
@@ -999,7 +1003,6 @@ errout:
const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = f2fs_encrypted_get_link,
- .put_link = kfree_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
.setxattr = generic_setxattr,
@@ -1035,7 +1038,6 @@ const struct inode_operations f2fs_dir_inode_operations = {
const struct inode_operations f2fs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = f2fs_get_link,
- .put_link = page_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
#ifdef CONFIG_F2FS_FS_XATTR
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index def0a4d..712601f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1366,7 +1366,8 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
}
static const char *fuse_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct fuse_conn *fc = get_fuse_conn(inode);
FUSE_ARGS(args);
@@ -1392,7 +1393,7 @@ static const char *fuse_get_link(struct dentry *dentry,
link = ERR_PTR(ret);
} else {
link[ret] = '\0';
- *cookie = link;
+ set_delayed_call(done, kfree_link, link);
}
fuse_invalidate_atime(inode);
return link;
@@ -1913,7 +1914,6 @@ static const struct inode_operations fuse_common_inode_operations = {
static const struct inode_operations fuse_symlink_inode_operations = {
.setattr = fuse_setattr,
.get_link = fuse_get_link,
- .put_link = kfree_put_link,
.readlink = generic_readlink,
.getattr = fuse_getattr,
.setxattr = fuse_setxattr,
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 10950560..1bae189 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1715,7 +1715,7 @@ static int gfs2_rename2(struct inode *odir, struct dentry *odentry,
* gfs2_get_link - Follow a symbolic link
* @dentry: The dentry of the link
* @inode: The inode of the link
- * @cookie: place to store the information for ->put_link()
+ * @done: destructor for return value
*
* This can handle symlinks of any size.
*
@@ -1723,7 +1723,8 @@ static int gfs2_rename2(struct inode *odir, struct dentry *odentry,
*/
static const char *gfs2_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder i_gh;
@@ -1764,7 +1765,7 @@ static const char *gfs2_get_link(struct dentry *dentry,
out:
gfs2_glock_dq_uninit(&i_gh);
if (!IS_ERR(buf))
- *cookie = buf;
+ set_delayed_call(done, kfree_link, buf);
return buf;
}
@@ -2138,7 +2139,6 @@ const struct inode_operations gfs2_dir_iops = {
const struct inode_operations gfs2_symlink_iops = {
.readlink = generic_readlink,
.get_link = gfs2_get_link,
- .put_link = kfree_put_link,
.permission = gfs2_permission,
.setattr = gfs2_setattr,
.getattr = gfs2_getattr,
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 6ce5309..7db524c 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -893,12 +893,13 @@ static const struct inode_operations hostfs_dir_iops = {
};
static const char *hostfs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
char *link;
if (!dentry)
return ERR_PTR(-ECHILD);
- link = __getname();
+ link = kmalloc(PATH_MAX, GFP_KERNEL);
if (link) {
char *path = dentry_name(dentry);
int err = -ENOMEM;
@@ -909,25 +910,20 @@ static const char *hostfs_get_link(struct dentry *dentry,
__putname(path);
}
if (err < 0) {
- __putname(link);
+ kfree(link);
return ERR_PTR(err);
}
} else {
return ERR_PTR(-ENOMEM);
}
- return *cookie = link;
-}
-
-static void hostfs_put_link(struct inode *unused, void *cookie)
-{
- __putname(cookie);
+ set_delayed_call(done, kfree_link, link);
+ return link;
}
static const struct inode_operations hostfs_link_iops = {
.readlink = generic_readlink,
.get_link = hostfs_get_link,
- .put_link = hostfs_put_link,
};
static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
diff --git a/fs/jfs/symlink.c b/fs/jfs/symlink.c
index 0211328..f8db4fd 100644
--- a/fs/jfs/symlink.c
+++ b/fs/jfs/symlink.c
@@ -34,7 +34,6 @@ const struct inode_operations jfs_fast_symlink_inode_operations = {
const struct inode_operations jfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = jfs_setattr,
.setxattr = jfs_setxattr,
.getxattr = jfs_getxattr,
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index f9efdae..117b8b3 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -113,22 +113,24 @@ static int kernfs_getlink(struct dentry *dentry, char *path)
}
static const char *kernfs_iop_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
- int error = -ENOMEM;
- char *page;
+ char *body;
+ int error;
if (!dentry)
return ERR_PTR(-ECHILD);
- page = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!page)
+ body = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!body)
return ERR_PTR(-ENOMEM);
- error = kernfs_getlink(dentry, page);
+ error = kernfs_getlink(dentry, body);
if (unlikely(error < 0)) {
- kfree(page);
+ kfree(body);
return ERR_PTR(error);
}
- return *cookie = page;
+ set_delayed_call(done, kfree_link, body);
+ return body;
}
const struct inode_operations kernfs_symlink_iops = {
@@ -138,7 +140,6 @@ const struct inode_operations kernfs_symlink_iops = {
.listxattr = kernfs_iop_listxattr,
.readlink = generic_readlink,
.get_link = kernfs_iop_get_link,
- .put_link = kfree_put_link,
.setattr = kernfs_iop_setattr,
.getattr = kernfs_iop_getattr,
.permission = kernfs_iop_permission,
diff --git a/fs/libfs.c b/fs/libfs.c
index fec7ab0..0149129 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1019,11 +1019,12 @@ int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync)
}
EXPORT_SYMBOL(noop_fsync);
-void kfree_put_link(struct inode *unused, void *cookie)
+/* Because kfree isn't assignment-compatible with void(void*) ;-/ */
+void kfree_link(void *p)
{
- kfree(cookie);
+ kfree(p);
}
-EXPORT_SYMBOL(kfree_put_link);
+EXPORT_SYMBOL(kfree_link);
/*
* nop .set_page_dirty method so that people can use .page_mkwrite on
@@ -1087,7 +1088,7 @@ simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
EXPORT_SYMBOL(simple_nosetlease);
const char *simple_get_link(struct dentry *dentry, struct inode *inode,
- void **cookie)
+ struct delayed_call *done)
{
return inode->i_link;
}
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 3cce709..cb1789c 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -436,7 +436,6 @@ static const struct address_space_operations minix_aops = {
static const struct inode_operations minix_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.getattr = minix_getattr,
};
diff --git a/fs/namei.c b/fs/namei.c
index 8f51788..3c909ae 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -505,13 +505,13 @@ struct nameidata {
int total_link_count;
struct saved {
struct path link;
- void *cookie;
+ struct delayed_call done;
const char *name;
- struct inode *inode;
unsigned seq;
} *stack, internal[EMBEDDED_LEVELS];
struct filename *name;
struct nameidata *saved;
+ struct inode *link_inode;
unsigned root_seq;
int dfd;
};
@@ -592,11 +592,8 @@ static void drop_links(struct nameidata *nd)
int i = nd->depth;
while (i--) {
struct saved *last = nd->stack + i;
- struct inode *inode = last->inode;
- if (last->cookie && inode->i_op->put_link) {
- inode->i_op->put_link(inode, last->cookie);
- last->cookie = NULL;
- }
+ do_delayed_call(&last->done);
+ clear_delayed_call(&last->done);
}
}
@@ -858,9 +855,7 @@ void nd_jump_link(struct path *path)
static inline void put_link(struct nameidata *nd)
{
struct saved *last = nd->stack + --nd->depth;
- struct inode *inode = last->inode;
- if (last->cookie && inode->i_op->put_link)
- inode->i_op->put_link(inode, last->cookie);
+ do_delayed_call(&last->done);
if (!(nd->flags & LOOKUP_RCU))
path_put(&last->link);
}
@@ -892,7 +887,7 @@ static inline int may_follow_link(struct nameidata *nd)
return 0;
/* Allowed if owner and follower match. */
- inode = nd->stack[0].inode;
+ inode = nd->link_inode;
if (uid_eq(current_cred()->fsuid, inode->i_uid))
return 0;
@@ -983,7 +978,7 @@ const char *get_link(struct nameidata *nd)
{
struct saved *last = nd->stack + nd->depth - 1;
struct dentry *dentry = last->link.dentry;
- struct inode *inode = last->inode;
+ struct inode *inode = nd->link_inode;
int error;
const char *res;
@@ -1004,23 +999,21 @@ const char *get_link(struct nameidata *nd)
nd->last_type = LAST_BIND;
res = inode->i_link;
if (!res) {
+ const char * (*get)(struct dentry *, struct inode *,
+ struct delayed_call *);
+ get = inode->i_op->get_link;
if (nd->flags & LOOKUP_RCU) {
- res = inode->i_op->get_link(NULL, inode,
- &last->cookie);
+ res = get(NULL, inode, &last->done);
if (res == ERR_PTR(-ECHILD)) {
if (unlikely(unlazy_walk(nd, NULL, 0)))
return ERR_PTR(-ECHILD);
- res = inode->i_op->get_link(dentry, inode,
- &last->cookie);
+ res = get(dentry, inode, &last->done);
}
} else {
- res = inode->i_op->get_link(dentry, inode,
- &last->cookie);
+ res = get(dentry, inode, &last->done);
}
- if (IS_ERR_OR_NULL(res)) {
- last->cookie = NULL;
+ if (IS_ERR_OR_NULL(res))
return res;
- }
}
if (*res == '/') {
if (nd->flags & LOOKUP_RCU) {
@@ -1699,8 +1692,8 @@ static int pick_link(struct nameidata *nd, struct path *link,
last = nd->stack + nd->depth++;
last->link = *link;
- last->cookie = NULL;
- last->inode = inode;
+ clear_delayed_call(&last->done);
+ nd->link_inode = inode;
last->seq = seq;
return 1;
}
@@ -4508,26 +4501,25 @@ EXPORT_SYMBOL(readlink_copy);
*/
int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
- void *cookie;
+ DEFINE_DELAYED_CALL(done);
struct inode *inode = d_inode(dentry);
const char *link = inode->i_link;
int res;
if (!link) {
- link = inode->i_op->get_link(dentry, inode, &cookie);
+ link = inode->i_op->get_link(dentry, inode, &done);
if (IS_ERR(link))
return PTR_ERR(link);
}
res = readlink_copy(buffer, buflen, link);
- if (inode->i_op->put_link)
- inode->i_op->put_link(inode, cookie);
+ do_delayed_call(&done);
return res;
}
EXPORT_SYMBOL(generic_readlink);
/* get the link contents into pagecache */
const char *page_get_link(struct dentry *dentry, struct inode *inode,
- void **cookie)
+ struct delayed_call *callback)
{
char *kaddr;
struct page *page;
@@ -4546,7 +4538,7 @@ const char *page_get_link(struct dentry *dentry, struct inode *inode,
if (IS_ERR(page))
return (char*)page;
}
- *cookie = page;
+ set_delayed_call(callback, page_put_link, page);
BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
kaddr = page_address(page);
nd_terminate_link(kaddr, inode->i_size, PAGE_SIZE - 1);
@@ -4555,21 +4547,19 @@ const char *page_get_link(struct dentry *dentry, struct inode *inode,
EXPORT_SYMBOL(page_get_link);
-void page_put_link(struct inode *unused, void *cookie)
+void page_put_link(void *arg)
{
- struct page *page = cookie;
- page_cache_release(page);
+ put_page(arg);
}
EXPORT_SYMBOL(page_put_link);
int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
- void *cookie = NULL;
+ DEFINE_DELAYED_CALL(done);
int res = readlink_copy(buffer, buflen,
page_get_link(dentry, d_inode(dentry),
- &cookie));
- if (cookie)
- page_put_link(NULL, cookie);
+ &done));
+ do_delayed_call(&done);
return res;
}
EXPORT_SYMBOL(page_readlink);
@@ -4619,6 +4609,5 @@ EXPORT_SYMBOL(page_symlink);
const struct inode_operations page_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
};
EXPORT_SYMBOL(page_symlink_inode_operations);
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 3ab6cdb..ce1eb3f 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -245,7 +245,6 @@ static void ncp_set_attr(struct inode *inode, struct ncp_entry_info *nwinfo)
static const struct inode_operations ncp_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = ncp_notify_change,
};
#endif
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index 95c69af..4fe3eea 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -43,7 +43,8 @@ error:
}
static const char *nfs_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct page *page;
void *err;
@@ -68,7 +69,7 @@ static const char *nfs_get_link(struct dentry *dentry,
if (IS_ERR(page))
return ERR_CAST(page);
}
- *cookie = page;
+ set_delayed_call(done, page_put_link, page);
return page_address(page);
}
@@ -78,7 +79,6 @@ static const char *nfs_get_link(struct dentry *dentry,
const struct inode_operations nfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = nfs_get_link,
- .put_link = page_put_link,
.getattr = nfs_getattr,
.setattr = nfs_setattr,
};
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 63dddb7..7ccdb96 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -570,7 +570,6 @@ const struct inode_operations nilfs_special_inode_operations = {
const struct inode_operations nilfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.permission = nilfs_permission,
};
diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index b4e79bc..6c2a3e3 100644
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -89,7 +89,6 @@ const struct address_space_operations ocfs2_fast_symlink_aops = {
const struct inode_operations ocfs2_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.getattr = ocfs2_getattr,
.setattr = ocfs2_setattr,
.setxattr = generic_setxattr,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 38a0b8b..964a60f 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -131,19 +131,12 @@ out_dput:
return err;
}
-
-struct ovl_link_data {
- struct dentry *realdentry;
- void *cookie;
-};
-
static const char *ovl_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct dentry *realdentry;
struct inode *realinode;
- struct ovl_link_data *data = NULL;
- const char *ret;
if (!dentry)
return ERR_PTR(-ECHILD);
@@ -154,38 +147,7 @@ static const char *ovl_get_link(struct dentry *dentry,
if (WARN_ON(!realinode->i_op->get_link))
return ERR_PTR(-EPERM);
- if (realinode->i_op->put_link) {
- data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
- if (!data)
- return ERR_PTR(-ENOMEM);
- data->realdentry = realdentry;
- }
-
- ret = realinode->i_op->get_link(realdentry, realinode, cookie);
- if (IS_ERR_OR_NULL(ret)) {
- kfree(data);
- return ret;
- }
-
- if (data)
- data->cookie = *cookie;
-
- *cookie = data;
-
- return ret;
-}
-
-static void ovl_put_link(struct inode *unused, void *c)
-{
- struct inode *realinode;
- struct ovl_link_data *data = c;
-
- if (!data)
- return;
-
- realinode = data->realdentry->d_inode;
- realinode->i_op->put_link(realinode, data->cookie);
- kfree(data);
+ return realinode->i_op->get_link(realdentry, realinode, done);
}
static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
@@ -383,7 +345,6 @@ static const struct inode_operations ovl_file_inode_operations = {
static const struct inode_operations ovl_symlink_inode_operations = {
.setattr = ovl_setattr,
.get_link = ovl_get_link,
- .put_link = ovl_put_link,
.readlink = ovl_readlink,
.getattr = ovl_getattr,
.setxattr = ovl_setxattr,
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1a489e2..71660bb 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1565,7 +1565,8 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
}
static const char *proc_pid_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct path path;
int error = -EACCES;
@@ -1949,12 +1950,13 @@ struct map_files_info {
*/
static const char *
proc_map_files_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
if (!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
- return proc_pid_get_link(dentry, inode, NULL);
+ return proc_pid_get_link(dentry, inode, done);
}
/*
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 10360b2..d0e9b9b 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -393,25 +393,25 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
};
#endif
+static void proc_put_link(void *p)
+{
+ unuse_pde(p);
+}
+
static const char *proc_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct proc_dir_entry *pde = PDE(inode);
if (unlikely(!use_pde(pde)))
return ERR_PTR(-EINVAL);
- *cookie = pde;
+ set_delayed_call(done, proc_put_link, pde);
return pde->data;
}
-static void proc_put_link(struct inode *unused, void *p)
-{
- unuse_pde(p);
-}
-
const struct inode_operations proc_link_inode_operations = {
.readlink = generic_readlink,
.get_link = proc_get_link,
- .put_link = proc_put_link,
};
struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 63861c1..1dece87 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -31,7 +31,8 @@ static const struct proc_ns_operations *ns_entries[] = {
};
static const char *proc_ns_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 7a8b19e..67e8db4 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -19,7 +19,8 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
}
static const char *proc_self_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
@@ -32,13 +33,13 @@ static const char *proc_self_get_link(struct dentry *dentry,
if (unlikely(!name))
return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d", tgid);
- return *cookie = name;
+ set_delayed_call(done, kfree_link, name);
+ return name;
}
static const struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
.get_link = proc_self_get_link,
- .put_link = kfree_put_link,
};
static unsigned self_inum;
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 03eaa84..9eacd59 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -20,7 +20,8 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
}
static const char *proc_thread_self_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
@@ -34,13 +35,13 @@ static const char *proc_thread_self_get_link(struct dentry *dentry,
if (unlikely(!name))
return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d/task/%d", tgid, pid);
- return *cookie = name;
+ set_delayed_call(done, kfree_link, name);
+ return name;
}
static const struct inode_operations proc_thread_self_inode_operations = {
.readlink = proc_thread_self_readlink,
.get_link = proc_thread_self_get_link,
- .put_link = kfree_put_link,
};
static unsigned thread_self_inum;
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index ecbf11e..2a12d46 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -1666,7 +1666,6 @@ const struct inode_operations reiserfs_dir_inode_operations = {
const struct inode_operations reiserfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.setattr = reiserfs_setattr,
.setxattr = reiserfs_setxattr,
.getxattr = reiserfs_getxattr,
diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c
index 7c635a5..dbcc2f5 100644
--- a/fs/squashfs/symlink.c
+++ b/fs/squashfs/symlink.c
@@ -120,7 +120,6 @@ const struct address_space_operations squashfs_symlink_aops = {
const struct inode_operations squashfs_symlink_inode_ops = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.getxattr = generic_getxattr,
.listxattr = squashfs_listxattr
};
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index 80a40bc..07ac18c 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -147,7 +147,6 @@ static inline void write3byte(struct sysv_sb_info *sbi,
static const struct inode_operations sysv_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
- .put_link = page_put_link,
.getattr = sysv_getattr,
};
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f638fd5..06eafaf 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -417,7 +417,7 @@ STATIC const char *
xfs_vn_get_link(
struct dentry *dentry,
struct inode *inode,
- void **cookie)
+ struct delayed_call *done)
{
char *link;
int error = -ENOMEM;
@@ -433,7 +433,8 @@ xfs_vn_get_link(
if (unlikely(error))
goto out_kfree;
- return *cookie = link;
+ set_delayed_call(done, kfree_link, link);
+ return link;
out_kfree:
kfree(link);
@@ -1177,7 +1178,6 @@ static const struct inode_operations xfs_dir_ci_inode_operations = {
static const struct inode_operations xfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = xfs_vn_get_link,
- .put_link = kfree_put_link,
.getattr = xfs_vn_getattr,
.setattr = xfs_vn_setattr,
.setxattr = generic_setxattr,
diff --git a/include/linux/delayed_call.h b/include/linux/delayed_call.h
new file mode 100644
index 0000000..f7fa76a
--- /dev/null
+++ b/include/linux/delayed_call.h
@@ -0,0 +1,34 @@
+#ifndef _DELAYED_CALL_H
+#define _DELAYED_CALL_H
+
+/*
+ * Poor man's closures; I wish we could've done them sanely polymorphic,
+ * but...
+ */
+
+struct delayed_call {
+ void (*fn)(void *);
+ void *arg;
+};
+
+#define DEFINE_DELAYED_CALL(name) struct delayed_call name = {NULL, NULL}
+
+/* I really wish we had closures with sane typechecking... */
+static inline void set_delayed_call(struct delayed_call *call,
+ void (*fn)(void *), void *arg)
+{
+ call->fn = fn;
+ call->arg = arg;
+}
+
+static inline void do_delayed_call(struct delayed_call *call)
+{
+ if (call->fn)
+ call->fn(call->arg);
+}
+
+static inline void clear_delayed_call(struct delayed_call *call)
+{
+ call->fn = NULL;
+}
+#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 138e206..5de5edb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -31,6 +31,7 @@
#include <linux/blk_types.h>
#include <linux/workqueue.h>
#include <linux/percpu-rwsem.h>
+#include <linux/delayed_call.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@@ -1633,12 +1634,11 @@ struct file_operations {
struct inode_operations {
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
- const char * (*get_link) (struct dentry *, struct inode *, void **);
+ const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
int (*permission) (struct inode *, int);
struct posix_acl * (*get_acl)(struct inode *, int);
int (*readlink) (struct dentry *, char __user *,int);
- void (*put_link) (struct inode *, void *);
int (*create) (struct inode *,struct dentry *, umode_t, bool);
int (*link) (struct dentry *,struct inode *,struct dentry *);
@@ -2736,13 +2736,14 @@ extern const struct file_operations generic_ro_fops;
extern int readlink_copy(char __user *, int, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
-extern const char *page_get_link(struct dentry *, struct inode *, void **);
-extern void page_put_link(struct inode *, void *);
+extern const char *page_get_link(struct dentry *, struct inode *,
+ struct delayed_call *);
+extern void page_put_link(void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
int nofs);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
-extern void kfree_put_link(struct inode *, void *);
+extern void kfree_link(void *);
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
@@ -2753,7 +2754,8 @@ void __inode_sub_bytes(struct inode *inode, loff_t bytes);
void inode_sub_bytes(struct inode *inode, loff_t bytes);
loff_t inode_get_bytes(struct inode *inode);
void inode_set_bytes(struct inode *inode, loff_t bytes);
-const char *simple_get_link(struct dentry *, struct inode *, void **);
+const char *simple_get_link(struct dentry *, struct inode *,
+ struct delayed_call *);
extern const struct inode_operations simple_symlink_inode_operations;
extern int iterate_dir(struct file *, struct dir_context *);
diff --git a/mm/shmem.c b/mm/shmem.c
index 0605716..bab9041 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2496,8 +2496,15 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return 0;
}
+static void shmem_put_link(void *arg)
+{
+ mark_page_accessed(arg);
+ put_page(arg);
+}
+
static const char *shmem_get_link(struct dentry *dentry,
- struct inode *inode, void **cookie)
+ struct inode *inode,
+ struct delayed_call *done)
{
struct page *page = NULL;
int error;
@@ -2515,17 +2522,10 @@ static const char *shmem_get_link(struct dentry *dentry,
return ERR_PTR(error);
unlock_page(page);
}
- *cookie = page;
+ set_delayed_call(done, shmem_put_link, page);
return page_address(page);
}
-static void shmem_put_link(struct inode *unused, void *cookie)
-{
- struct page *page = cookie;
- mark_page_accessed(page);
- page_cache_release(page);
-}
-
#ifdef CONFIG_TMPFS_XATTR
/*
* Superblocks without xattr inode operations may get some security.* xattr
@@ -2680,7 +2680,6 @@ static const struct inode_operations shmem_short_symlink_operations = {
static const struct inode_operations shmem_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = shmem_get_link,
- .put_link = shmem_put_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
--
2.1.4
^ permalink raw reply related [flat|nested] 19+ messages in thread* Re: [RFC] ->get_link(), ->put_link() and cookies
2016-01-01 6:36 [RFC] ->get_link(), ->put_link() and cookies Al Viro
` (12 preceding siblings ...)
2016-01-01 6:38 ` [PATCH 13/13] switch ->get_link() to delayed_call, kill ->put_link() Al Viro
@ 2016-01-03 19:53 ` Linus Torvalds
2016-01-03 20:21 ` Al Viro
13 siblings, 1 reply; 19+ messages in thread
From: Linus Torvalds @ 2016-01-03 19:53 UTC (permalink / raw)
To: Al Viro; +Cc: Linux Kernel Mailing List, linux-fsdevel
On Thu, Dec 31, 2015 at 10:36 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> In cases when we need to pin the symlink body in some manner, we
> need to undo whatever we'd done once the caller is done with the body.
> That went through several variants, the latest (in -next right now) being
> "have non-NULL ->put_link() and leave an argument for it in void *cookie,
> address of which is passed to ->get_link()".
The series looks ok to me, even if I still am not a fan of the cookie.
I suspect the remaining users could easily embed the returned string
at the end of a structure, and get their data with container_of(). It
would complicate their unusual behavior for sure, but make the common
case much more understandable.
Oh well. I won't insist - it may be too painful to be worth it. And
it's a fairly separate issue anyway.
So no objections to this series.
Linus
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [RFC] ->get_link(), ->put_link() and cookies
2016-01-03 19:53 ` [RFC] ->get_link(), ->put_link() and cookies Linus Torvalds
@ 2016-01-03 20:21 ` Al Viro
2016-01-03 20:41 ` Linus Torvalds
0 siblings, 1 reply; 19+ messages in thread
From: Al Viro @ 2016-01-03 20:21 UTC (permalink / raw)
To: Linus Torvalds; +Cc: Linux Kernel Mailing List, linux-fsdevel
On Sun, Jan 03, 2016 at 11:53:21AM -0800, Linus Torvalds wrote:
> On Thu, Dec 31, 2015 at 10:36 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> > In cases when we need to pin the symlink body in some manner, we
> > need to undo whatever we'd done once the caller is done with the body.
> > That went through several variants, the latest (in -next right now) being
> > "have non-NULL ->put_link() and leave an argument for it in void *cookie,
> > address of which is passed to ->get_link()".
>
> The series looks ok to me, even if I still am not a fan of the cookie.
> I suspect the remaining users could easily embed the returned string
> at the end of a structure, and get their data with container_of(). It
> would complicate their unusual behavior for sure, but make the common
> case much more understandable.
>
> Oh well. I won't insist - it may be too painful to be worth it. And
> it's a fairly separate issue anyway.
>
> So no objections to this series.
Just to make sure - that does include 13/13, presumably? IOW, ->put_link()
is gone and the final calling conventions for ->get_link() are
const char *(*get_link)(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done);
with dentry == NULL <=> call in RCU mode, ERR_PTR(-E...) returned on error
and set_delayed_call(done, destructor, arg) done if destructor(arg) should
be done once pathname resolution is through with the body returned by
->get_link().
^ permalink raw reply [flat|nested] 19+ messages in thread
* Re: [RFC] ->get_link(), ->put_link() and cookies
2016-01-03 20:21 ` Al Viro
@ 2016-01-03 20:41 ` Linus Torvalds
2016-01-03 21:40 ` Al Viro
0 siblings, 1 reply; 19+ messages in thread
From: Linus Torvalds @ 2016-01-03 20:41 UTC (permalink / raw)
To: Al Viro; +Cc: Linux Kernel Mailing List, linux-fsdevel
On Sun, Jan 3, 2016 at 12:21 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> Just to make sure - that does include 13/13, presumably?
Ugh, no, I had set that aside and then forgot all about it.
I'm not sure about 13/13. I'm ok with it, but I'm not sure it's any
less confusing than the cookie was.
I like how it removes "put_link()" as a callback, but at the same time
I think it's even more abstract than the cookie was.
The main worry I have is that the naming is generic, but there's only
a single very specialized use for it. Do we expect other uses?
Because if not, I think it would be clearer if it was named to be more
concretely about putlink, and avoid the fact that it feels very
abstract.
Don't get me wrong - abstract generalized helper functions are cool.
But people aren't very abstract, and it tends to make for confusing
code when you aren't intimately familiar with the rules.
Linus
^ permalink raw reply [flat|nested] 19+ messages in thread* Re: [RFC] ->get_link(), ->put_link() and cookies
2016-01-03 20:41 ` Linus Torvalds
@ 2016-01-03 21:40 ` Al Viro
0 siblings, 0 replies; 19+ messages in thread
From: Al Viro @ 2016-01-03 21:40 UTC (permalink / raw)
To: Linus Torvalds; +Cc: Linux Kernel Mailing List, linux-fsdevel
On Sun, Jan 03, 2016 at 12:41:47PM -0800, Linus Torvalds wrote:
> I like how it removes "put_link()" as a callback, but at the same time
> I think it's even more abstract than the cookie was.
>
> The main worry I have is that the naming is generic, but there's only
> a single very specialized use for it. Do we expect other uses?
Quite possibly - I don't have anything specific planned right now, but
I would be surprised if there hadn't been open-coded equivalents
of that thing in many places, and not only "too many instances to touch"
kind of holy cows, at that (timers are obviously very similar, but these
_do_ have way too many instances to even think of converting them).
> Because if not, I think it would be clearer if it was named to be more
> concretely about putlink, and avoid the fact that it feels very
> abstract.
>
> Don't get me wrong - abstract generalized helper functions are cool.
> But people aren't very abstract, and it tends to make for confusing
> code when you aren't intimately familiar with the rules.
The rules are pretty simple - there are 4 primitives total.
1) DEFINE_DELAYED_CALL(name) - usual DEFINE_MUTEX, etc. style initialized
declaration.
2) set_delayed_call(delayed_call, function, argument) - function is
void(void *), argument is void *. A-la setup_timer().
3) clear_delayed_call(delayed_call) - resets.
4) do_delayed_call(delayed_call) - evaluates.
That's it. If you have better suggestions re names, I'd be glad to take
them, but the set of primitives and the rules to go with those are as
simple as it gets.
Sure, we can give it a less generic name for now and just do what we'd done
for another generic thing (rcu_head, aka callback_head) when unrelated
uses show up, but I don't see much point going that way, TBH...
^ permalink raw reply [flat|nested] 19+ messages in thread