* [RFC][PATCH] filesystem helpers for custom 'struct file's
@ 2006-09-20 15:36 Dave Hansen
2006-10-07 8:27 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: Dave Hansen @ 2006-09-20 15:36 UTC (permalink / raw)
To: linux-kernel; +Cc: hch, Dave Hansen
Some filesystems forego the vfs and may_open() and create their
own 'struct file's.
This patch creates a couple of helper functions which can be
used by these filesystems, and will provide a unified place
which the r/o bind mount code may patch.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---
lxc-dave/include/linux/file.h | 8 ++++++++
lxc-dave/fs/file_table.c | 30 ++++++++++++++++++++++++++++++
lxc-dave/fs/hugetlbfs/inode.c | 22 +++++++++-------------
lxc-dave/mm/shmem.c | 7 ++-----
lxc-dave/mm/tiny-shmem.c | 24 +++++++++---------------
lxc-dave/net/socket.c | 17 ++++++++---------
6 files changed, 66 insertions(+), 42 deletions(-)
diff -puN include/linux/file.h~B0-helpers-for-custom-struct_files include/linux/file.h
--- lxc/include/linux/file.h~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/include/linux/file.h 2006-09-19 10:36:57.000000000 -0700
@@ -67,6 +67,14 @@ struct files_struct {
extern void FASTCALL(__fput(struct file *));
extern void FASTCALL(fput(struct file *));
+struct file_operations;
+struct vfsmount;
+struct dentry;
+extern int f_init(struct file *, struct vfsmount *, struct dentry *dentry,
+ mode_t mode, const struct file_operations *fop);
+extern struct file *f_alloc(struct vfsmount *, struct dentry *dentry,
+ mode_t mode, const struct file_operations *fop);
+
static inline void fput_light(struct file *file, int fput_needed)
{
if (unlikely(fput_needed))
diff -puN fs/file_table.c~B0-helpers-for-custom-struct_files fs/file_table.c
--- lxc/fs/file_table.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/fs/file_table.c 2006-09-19 10:36:57.000000000 -0700
@@ -140,6 +140,36 @@ fail:
EXPORT_SYMBOL(get_empty_filp);
+struct file *f_alloc(struct vfsmount *mnt, struct dentry *dentry,
+ mode_t mode, const struct file_operations *fop)
+{
+ struct file *file;
+
+ file = get_empty_filp();
+ if (!file)
+ return NULL;
+
+ f_init(file, mnt, dentry, mode, fop);
+ return file;
+}
+
+EXPORT_SYMBOL(f_alloc);
+
+int f_init(struct file *file, struct vfsmount *mnt,
+ struct dentry *dentry, mode_t mode,
+ const struct file_operations *fop)
+{
+ int error = 0;
+ file->f_vfsmnt = mntget(mnt);
+ file->f_dentry = dentry;
+ file->f_mapping = dentry->d_inode->i_mapping;
+ file->f_mode = mode;
+ file->f_op = fop;
+ return error;
+}
+
+EXPORT_SYMBOL(f_init);
+
void fastcall fput(struct file *file)
{
if (atomic_dec_and_test(&file->f_count))
diff -puN fs/hugetlbfs/inode.c~B0-helpers-for-custom-struct_files fs/hugetlbfs/inode.c
--- lxc/fs/hugetlbfs/inode.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/fs/hugetlbfs/inode.c 2006-09-19 10:36:57.000000000 -0700
@@ -764,16 +764,11 @@ struct file *hugetlb_zero_setup(size_t s
if (!dentry)
goto out_shm_unlock;
- error = -ENFILE;
- file = get_empty_filp();
- if (!file)
- goto out_dentry;
-
error = -ENOSPC;
inode = hugetlbfs_get_inode(root->d_sb, current->fsuid,
current->fsgid, S_IFREG | S_IRWXUGO, 0);
if (!inode)
- goto out_file;
+ goto out_dentry;
error = -ENOMEM;
if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT))
@@ -782,17 +777,18 @@ struct file *hugetlb_zero_setup(size_t s
d_instantiate(dentry, inode);
inode->i_size = size;
inode->i_nlink = 0;
- file->f_vfsmnt = mntget(hugetlbfs_vfsmount);
- file->f_dentry = dentry;
- file->f_mapping = inode->i_mapping;
- file->f_op = &hugetlbfs_file_operations;
- file->f_mode = FMODE_WRITE | FMODE_READ;
+
+ error = -ENFILE;
+ file = f_alloc(hugetlbfs_vfsmount, dentry,
+ FMODE_WRITE | FMODE_READ,
+ &hugetlbfs_file_operations);
+ if (!file)
+ goto out_inode;
+
return file;
out_inode:
iput(inode);
-out_file:
- put_filp(file);
out_dentry:
dput(dentry);
out_shm_unlock:
diff -puN mm/shmem.c~B0-helpers-for-custom-struct_files mm/shmem.c
--- lxc/mm/shmem.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/mm/shmem.c 2006-09-19 10:36:57.000000000 -0700
@@ -2411,11 +2411,8 @@ struct file *shmem_file_setup(char *name
d_instantiate(dentry, inode);
inode->i_size = size;
inode->i_nlink = 0; /* It is unlinked */
- file->f_vfsmnt = mntget(shm_mnt);
- file->f_dentry = dentry;
- file->f_mapping = inode->i_mapping;
- file->f_op = &shmem_file_operations;
- file->f_mode = FMODE_WRITE | FMODE_READ;
+ f_init(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
+ &shmem_file_operations);
return file;
close_file:
diff -puN mm/tiny-shmem.c~B0-helpers-for-custom-struct_files mm/tiny-shmem.c
--- lxc/mm/tiny-shmem.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/mm/tiny-shmem.c 2006-09-19 10:36:57.000000000 -0700
@@ -66,24 +66,19 @@ struct file *shmem_file_setup(char *name
if (!dentry)
goto put_memory;
- error = -ENFILE;
- file = get_empty_filp();
- if (!file)
- goto put_dentry;
-
error = -ENOSPC;
inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0);
if (!inode)
- goto close_file;
+ goto put_dentry;
d_instantiate(dentry, inode);
- inode->i_nlink = 0; /* It is unlinked */
+ error = -ENFILE;
+ file = f_alloc(shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
+ &ramfs_file_operations);
+ if (!file)
+ goto put_inode;
- file->f_vfsmnt = mntget(shm_mnt);
- file->f_dentry = dentry;
- file->f_mapping = inode->i_mapping;
- file->f_op = &ramfs_file_operations;
- file->f_mode = FMODE_WRITE | FMODE_READ;
+ inode->i_nlink = 0; /* It is unlinked */
/* notify everyone as to the change of file size */
error = do_truncate(dentry, size, 0, file);
@@ -91,9 +86,8 @@ struct file *shmem_file_setup(char *name
goto close_file;
return file;
-
-close_file:
- put_filp(file);
+put_inode:
+ iput(inode);
put_dentry:
dput(dentry);
put_memory:
diff -puN net/socket.c~B0-helpers-for-custom-struct_files net/socket.c
--- lxc/net/socket.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
+++ lxc-dave/net/socket.c 2006-09-19 10:36:57.000000000 -0700
@@ -349,6 +349,7 @@ static int sock_alloc_fd(struct file **f
static int sock_attach_fd(struct socket *sock, struct file *file)
{
+ struct dentry *dentry;
struct qstr this;
char name[32];
@@ -356,18 +357,16 @@ static int sock_attach_fd(struct socket
this.name = name;
this.hash = SOCK_INODE(sock)->i_ino;
- file->f_dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
- if (unlikely(!file->f_dentry))
+ dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
+ if (unlikely(!dentry))
return -ENOMEM;
- file->f_dentry->d_op = &sockfs_dentry_operations;
- d_add(file->f_dentry, SOCK_INODE(sock));
- file->f_vfsmnt = mntget(sock_mnt);
- file->f_mapping = file->f_dentry->d_inode->i_mapping;
-
+ dentry->d_op = &sockfs_dentry_operations;
+ d_add(dentry, SOCK_INODE(sock));
+ f_init(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE,
+ &socket_file_ops);
+ SOCK_INODE(sock)->i_fop = &socket_file_ops;
sock->file = file;
- file->f_op = SOCK_INODE(sock)->i_fop = &socket_file_ops;
- file->f_mode = FMODE_READ | FMODE_WRITE;
file->f_flags = O_RDWR;
file->f_pos = 0;
file->private_data = sock;
_
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [RFC][PATCH] filesystem helpers for custom 'struct file's
2006-09-20 15:36 [RFC][PATCH] filesystem helpers for custom 'struct file's Dave Hansen
@ 2006-10-07 8:27 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2006-10-07 8:27 UTC (permalink / raw)
To: Dave Hansen; +Cc: linux-kernel, hch
On Wed, Sep 20, 2006 at 08:36:38AM -0700, Dave Hansen wrote:
> Some filesystems forego the vfs and may_open() and create their
> own 'struct file's.
>
> This patch creates a couple of helper functions which can be
> used by these filesystems, and will provide a unified place
> which the r/o bind mount code may patch.
>
> Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
> ---
>
> lxc-dave/include/linux/file.h | 8 ++++++++
> lxc-dave/fs/file_table.c | 30 ++++++++++++++++++++++++++++++
> lxc-dave/fs/hugetlbfs/inode.c | 22 +++++++++-------------
> lxc-dave/mm/shmem.c | 7 ++-----
> lxc-dave/mm/tiny-shmem.c | 24 +++++++++---------------
> lxc-dave/net/socket.c | 17 ++++++++---------
> 6 files changed, 66 insertions(+), 42 deletions(-)
>
> diff -puN include/linux/file.h~B0-helpers-for-custom-struct_files include/linux/file.h
> --- lxc/include/linux/file.h~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
> +++ lxc-dave/include/linux/file.h 2006-09-19 10:36:57.000000000 -0700
> @@ -67,6 +67,14 @@ struct files_struct {
> extern void FASTCALL(__fput(struct file *));
> extern void FASTCALL(fput(struct file *));
>
> +struct file_operations;
> +struct vfsmount;
> +struct dentry;
> +extern int f_init(struct file *, struct vfsmount *, struct dentry *dentry,
> + mode_t mode, const struct file_operations *fop);
> +extern struct file *f_alloc(struct vfsmount *, struct dentry *dentry,
> + mode_t mode, const struct file_operations *fop);
> +
To be honest I really hate this names. init_file and alloc_file sound
a lot better.
> +int f_init(struct file *file, struct vfsmount *mnt,
> + struct dentry *dentry, mode_t mode,
> + const struct file_operations *fop)
> +{
> + int error = 0;
> + file->f_vfsmnt = mntget(mnt);
> + file->f_dentry = dentry;
> + file->f_mapping = dentry->d_inode->i_mapping;
> + file->f_mode = mode;
> + file->f_op = fop;
> + return error;
> +}
> +
> +EXPORT_SYMBOL(f_init);
Do we really need this one? I think we should only need the
alloc version.
> diff -puN mm/shmem.c~B0-helpers-for-custom-struct_files mm/shmem.c
> --- lxc/mm/shmem.c~B0-helpers-for-custom-struct_files 2006-09-19 10:36:47.000000000 -0700
> +++ lxc-dave/mm/shmem.c 2006-09-19 10:36:57.000000000 -0700
> @@ -2411,11 +2411,8 @@ struct file *shmem_file_setup(char *name
> d_instantiate(dentry, inode);
> inode->i_size = size;
> inode->i_nlink = 0; /* It is unlinked */
> - file->f_vfsmnt = mntget(shm_mnt);
> - file->f_dentry = dentry;
> - file->f_mapping = inode->i_mapping;
> - file->f_op = &shmem_file_operations;
> - file->f_mode = FMODE_WRITE | FMODE_READ;
> + f_init(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
> + &shmem_file_operations);
> return file;
>
This should be able to use the alloc variant by moving the file allocation
after the inode allocation. Which makes a lot of sense anyway as
shmem_get_inode can fail for accounting reasons.
> {
> + struct dentry *dentry;
> struct qstr this;
> char name[32];
>
> @@ -356,18 +357,16 @@ static int sock_attach_fd(struct socket
> this.name = name;
> this.hash = SOCK_INODE(sock)->i_ino;
>
> - file->f_dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
> - if (unlikely(!file->f_dentry))
> + dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
> + if (unlikely(!dentry))
> return -ENOMEM;
>
> - file->f_dentry->d_op = &sockfs_dentry_operations;
> - d_add(file->f_dentry, SOCK_INODE(sock));
> - file->f_vfsmnt = mntget(sock_mnt);
> - file->f_mapping = file->f_dentry->d_inode->i_mapping;
> -
> + dentry->d_op = &sockfs_dentry_operations;
> + d_add(dentry, SOCK_INODE(sock));
> + f_init(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE,
> + &socket_file_ops);
> + SOCK_INODE(sock)->i_fop = &socket_file_ops;
> sock->file = file;
> - file->f_op = SOCK_INODE(sock)->i_fop = &socket_file_ops;
> - file->f_mode = FMODE_READ | FMODE_WRITE;
> file->f_flags = O_RDWR;
> file->f_pos = 0;
> file->private_data = sock;
Similarly the socket code wants a rework. The current split into sock_alloc_fd
and sock_attach_fd is highly confusing and the allocation of the file struct
before the inode doesn't make a lot of sense.
^ permalink raw reply [flat|nested] 2+ messages in thread
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