[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry
Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.
This complements the get_sb() patch. That reduced the significance of
sb->s_root, allowing NFS to place a fake root there. However, NFS does
require a dentry to use as a target for the statfs operation. This permits
the root in the vfsmount to be used instead.
linux/mount.h has been added where necessary to make allyesconfig build
successfully.
Interest has also been expressed for use with the FUSE and XFS filesystems.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/open.c b/fs/open.c
index 4f178ac..a37ff86 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -31,18 +31,18 @@
#include <asm/unistd.h>
-int vfs_statfs(struct super_block *sb, struct kstatfs *buf)
+int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int retval = -ENODEV;
- if (sb) {
+ if (dentry) {
retval = -ENOSYS;
- if (sb->s_op->statfs) {
+ if (dentry->d_sb->s_op->statfs) {
memset(buf, 0, sizeof(*buf));
- retval = security_sb_statfs(sb);
+ retval = security_sb_statfs(dentry);
if (retval)
return retval;
- retval = sb->s_op->statfs(sb, buf);
+ retval = dentry->d_sb->s_op->statfs(dentry, buf);
if (retval == 0 && buf->f_frsize == 0)
buf->f_frsize = buf->f_bsize;
}
@@ -52,12 +52,12 @@
EXPORT_SYMBOL(vfs_statfs);
-static int vfs_statfs_native(struct super_block *sb, struct statfs *buf)
+static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
{
struct kstatfs st;
int retval;
- retval = vfs_statfs(sb, &st);
+ retval = vfs_statfs(dentry, &st);
if (retval)
return retval;
@@ -95,12 +95,12 @@
return 0;
}
-static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf)
+static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
{
struct kstatfs st;
int retval;
- retval = vfs_statfs(sb, &st);
+ retval = vfs_statfs(dentry, &st);
if (retval)
return retval;
@@ -130,7 +130,7 @@
error = user_path_walk(path, &nd);
if (!error) {
struct statfs tmp;
- error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp);
+ error = vfs_statfs_native(nd.dentry, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
path_release(&nd);
@@ -149,7 +149,7 @@
error = user_path_walk(path, &nd);
if (!error) {
struct statfs64 tmp;
- error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp);
+ error = vfs_statfs64(nd.dentry, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
path_release(&nd);
@@ -168,7 +168,7 @@
file = fget(fd);
if (!file)
goto out;
- error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp);
+ error = vfs_statfs_native(file->f_dentry, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
fput(file);
@@ -189,7 +189,7 @@
file = fget(fd);
if (!file)
goto out;
- error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp);
+ error = vfs_statfs64(file->f_dentry, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
fput(file);