[rfc][patch 2/3] fs: make use of new helper functions

Nick Piggin
2009-07-06T16:17:31Z

Update some fs code to make use of new helper functions introduced
in the previous patch. Should be no significant change in behaviour
(except CIFS now calls send_sig under i_lock, via inode_truncate_ok).

---
fs/buffer.c | 10 +--------
fs/cifs/inode.c | 51 ++++++++-----------------------------------------
fs/fuse/dir.c | 13 +++---------
fs/fuse/fuse_i.h | 2 -
fs/fuse/inode.c | 10 ---------
fs/nfs/inode.c | 52 +++++++++++---------------------------------------
fs/ramfs/file-nommu.c | 18 ++++-------------
7 files changed, 33 insertions(+), 123 deletions(-)

Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -2228,16 +2228,10 @@ int generic_cont_expand_simple(struct in
struct address_space *mapping = inode->i_mapping;
struct page *page;
void *fsdata;
- unsigned long limit;
int err;

- err = -EFBIG;
- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && size > (loff_t)limit) {
- send_sig(SIGXFSZ, current, 0);
- goto out;
- }
- if (size > inode->i_sb->s_maxbytes)
+ err = inode_truncate_ok(inode, size);
+ if (err)
goto out;

err = pagecache_write_begin(NULL, mapping, size, 0,
Index: linux-2.6/fs/cifs/inode.c
===================================================================
--- linux-2.6.orig/fs/cifs/inode.c
+++ linux-2.6/fs/cifs/inode.c
@@ -1645,57 +1645,24 @@ static int cifs_truncate_page(struct add

static int cifs_vmtruncate(struct inode *inode, loff_t offset)
{
- struct address_space *mapping = inode->i_mapping;
- unsigned long limit;
+ loff_t oldsize;
+ int err;

spin_lock(&inode->i_lock);
- if (inode->i_size < offset)
- goto do_expand;
- /*
- * truncation of in-use swapfiles is disallowed - it would cause
- * subsequent swapout to scribble on the now-freed blocks.
- */
- if (IS_SWAPFILE(inode)) {
+ err = inode_truncate_ok(inode, offset);
+ if (err) {
spin_unlock(&inode->i_lock);
- goto out_busy;
+ goto out;
}
- i_size_write(inode, offset);
- spin_unlock(&inode->i_lock);
- /*
- * unmap_mapping_range is called twice, first simply for efficiency
- * so that truncate_inode_pages does fewer single-page unmaps. However
- * after this first call, and before truncate_inode_pages finishes,
- * it is possible for private pages to be COWed, which remain after
- * truncate_inode_pages finishes, hence the second unmap_mapping_range
- * call must be made for correctness.
- */
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(mapping, offset);
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- goto out_truncate;

-do_expand:
- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && offset > limit) {
- spin_unlock(&inode->i_lock);
- goto out_sig;
- }
- if (offset > inode->i_sb->s_maxbytes) {
- spin_unlock(&inode->i_lock);
- goto out_big;
- }
+ oldsize = inode->i_size;
i_size_write(inode, offset);
spin_unlock(&inode->i_lock);
-out_truncate:
+ truncate_pagecache(inode, oldsize, offset);
if (inode->i_op->truncate)
inode->i_op->truncate(inode);
- return 0;
-out_sig:
- send_sig(SIGXFSZ, current, 0);
-out_big:
- return -EFBIG;
-out_busy:
- return -ETXTBSY;
+out:
+ return err;
}

static int
Index: linux-2.6/fs/fuse/dir.c
===================================================================
--- linux-2.6.orig/fs/fuse/dir.c
+++ linux-2.6/fs/fuse/dir.c
@@ -1225,14 +1225,9 @@ static int fuse_do_setattr(struct dentry
return 0;

if (attr->ia_valid & ATTR_SIZE) {
- unsigned long limit;
- if (IS_SWAPFILE(inode))
- return -ETXTBSY;
- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
- send_sig(SIGXFSZ, current, 0);
- return -EFBIG;
- }
+ err = inode_truncate_ok(inode, attr->ia_size);
+ if (err)
+ return err;
is_truncate = true;
}

@@ -1300,7 +1295,7 @@ static int fuse_do_setattr(struct dentry
*/
if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
if (outarg.attr.size < oldsize)
- fuse_truncate(inode->i_mapping, outarg.attr.size);
+ truncate_pagecache(inode, oldsize, outarg.attr.size);
invalidate_inode_pages2(inode->i_mapping);
}

Index: linux-2.6/fs/nfs/inode.c
===================================================================
--- linux-2.6.orig/fs/nfs/inode.c
+++ linux-2.6/fs/nfs/inode.c
@@ -427,49 +427,21 @@ nfs_setattr(struct dentry *dentry, struc
*/
static int nfs_vmtruncate(struct inode * inode, loff_t offset)
{
- if (i_size_read(inode) < offset) {
- unsigned long limit;
+ loff_t oldsize;
+ int err;

- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && offset > limit)
- goto out_sig;
- if (offset > inode->i_sb->s_maxbytes)
- goto out_big;
- spin_lock(&inode->i_lock);
- i_size_write(inode, offset);
- spin_unlock(&inode->i_lock);
- } else {
- struct address_space *mapping = inode->i_mapping;
+ err = inode_truncate_ok(inode, offset);
+ if (err)
+ goto out;

- /*
- * truncation of in-use swapfiles is disallowed - it would
- * cause subsequent swapout to scribble on the now-freed
- * blocks.
- */
- if (IS_SWAPFILE(inode))
- return -ETXTBSY;
- spin_lock(&inode->i_lock);
- i_size_write(inode, offset);
- spin_unlock(&inode->i_lock);
+ spin_lock(&inode->i_lock);
+ oldsize = inode->i_size;
+ i_size_write(inode, offset);
+ spin_unlock(&inode->i_lock);

- /*
- * unmap_mapping_range is called twice, first simply for
- * efficiency so that truncate_inode_pages does fewer
- * single-page unmaps. However after this first call, and
- * before truncate_inode_pages finishes, it is possible for
- * private pages to be COWed, which remain after
- * truncate_inode_pages finishes, hence the second
- * unmap_mapping_range call must be made for correctness.
- */
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(mapping, offset);
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- }
- return 0;
-out_sig:
- send_sig(SIGXFSZ, current, 0);
-out_big:
- return -EFBIG;
+ truncate_pagecache(inode, oldsize, offset);
+out:
+ return err;
}

/**
Index: linux-2.6/fs/ramfs/file-nommu.c
===================================================================
--- linux-2.6.orig/fs/ramfs/file-nommu.c
+++ linux-2.6/fs/ramfs/file-nommu.c
@@ -68,14 +68,11 @@ int ramfs_nommu_expand_for_mapping(struc
/* make various checks */
order = get_order(newsize);
if (unlikely(order >= MAX_ORDER))
- goto too_big;
+ return -EFBIG;

- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && newsize > limit)
- goto fsize_exceeded;
-
- if (newsize > inode->i_sb->s_maxbytes)
- goto too_big;
+ ret = inode_truncate_ok(inode, newsize);
+ if (ret)
+ return ret;

i_size_write(inode, newsize);

@@ -117,12 +114,7 @@ int ramfs_nommu_expand_for_mapping(struc

return 0;

- fsize_exceeded:
- send_sig(SIGXFSZ, current, 0);
- too_big:
- return -EFBIG;
-
- add_error:
+add_error:
while (loop < npages)
__free_page(pages + loop++);
return ret;
Index: linux-2.6/fs/fuse/fuse_i.h
===================================================================
--- linux-2.6.orig/fs/fuse/fuse_i.h
+++ linux-2.6/fs/fuse/fuse_i.h
@@ -588,8 +588,6 @@ void fuse_change_attributes(struct inode
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
u64 attr_valid);

-void fuse_truncate(struct address_space *mapping, loff_t offset);
-
/**
* Initialize the client device
*/
Index: linux-2.6/fs/fuse/inode.c
===================================================================
--- linux-2.6.orig/fs/fuse/inode.c
+++ linux-2.6/fs/fuse/inode.c
@@ -115,14 +115,6 @@ static int fuse_remount_fs(struct super_
return 0;
}

-void fuse_truncate(struct address_space *mapping, loff_t offset)
-{
- /* See vmtruncate() */
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(mapping, offset);
- unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
-}
-
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
u64 attr_valid)
{
@@ -181,7 +173,7 @@ void fuse_change_attributes(struct inode

if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
if (attr->size < oldsize)
- fuse_truncate(inode->i_mapping, attr->size);
+ truncate_pagecache(inode, oldsize, attr->size);
invalidate_inode_pages2(inode->i_mapping);
}
}