From 726c334223180e3c0197cc980a432681370d4baf Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 23 Jun 2006 02:02:58 -0700 Subject: [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 Acked-by: Al Viro Cc: Nathan Scott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/coda_psdev.h | 2 +- include/linux/fs.h | 6 +++--- include/linux/mount.h | 5 +++++ include/linux/security.h | 14 +++++++------- 4 files changed, 16 insertions(+), 11 deletions(-) (limited to 'include') diff --git a/include/linux/coda_psdev.h b/include/linux/coda_psdev.h index d539262..98f6c52 100644 --- a/include/linux/coda_psdev.h +++ b/include/linux/coda_psdev.h @@ -70,7 +70,7 @@ int venus_pioctl(struct super_block *sb, struct CodaFid *fid, unsigned int cmd, struct PioctlData *data); int coda_downcall(int opcode, union outputArgs *out, struct super_block *sb); int venus_fsync(struct super_block *sb, struct CodaFid *fid); -int venus_statfs(struct super_block *sb, struct kstatfs *sfs); +int venus_statfs(struct dentry *dentry, struct kstatfs *sfs); /* messages between coda filesystem in kernel and Venus */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 3e50dd2..c823a38 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1096,7 +1096,7 @@ struct super_operations { int (*sync_fs)(struct super_block *sb, int wait); void (*write_super_lockfs) (struct super_block *); void (*unlockfs) (struct super_block *); - int (*statfs) (struct super_block *, struct kstatfs *); + int (*statfs) (struct dentry *, struct kstatfs *); int (*remount_fs) (struct super_block *, int *, char *); void (*clear_inode) (struct inode *); void (*umount_begin) (struct super_block *); @@ -1325,7 +1325,7 @@ extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int); extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *, struct vfsmount *); -extern int vfs_statfs(struct super_block *, struct kstatfs *); +extern int vfs_statfs(struct dentry *, struct kstatfs *); /* /sys/fs */ extern struct subsystem fs_subsys; @@ -1746,7 +1746,7 @@ extern int dcache_dir_close(struct inode *, struct file *); extern loff_t dcache_dir_lseek(struct file *, loff_t, int); extern int dcache_readdir(struct file *, void *, filldir_t); extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *); -extern int simple_statfs(struct super_block *, struct kstatfs *); +extern int simple_statfs(struct dentry *, struct kstatfs *); extern int simple_link(struct dentry *, struct inode *, struct dentry *); extern int simple_unlink(struct inode *, struct dentry *); extern int simple_rmdir(struct inode *, struct dentry *); diff --git a/include/linux/mount.h b/include/linux/mount.h index b7472ae..60718f1 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -17,6 +17,11 @@ #include #include +struct super_block; +struct vfsmount; +struct dentry; +struct namespace; + #define MNT_NOSUID 0x01 #define MNT_NODEV 0x02 #define MNT_NOEXEC 0x04 diff --git a/include/linux/security.h b/include/linux/security.h index 47722d3..383c320 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -171,9 +171,9 @@ struct swap_info_struct; * Deallocate and clear the sb->s_security field. * @sb contains the super_block structure to be modified. * @sb_statfs: - * Check permission before obtaining filesystem statistics for the @sb - * filesystem. - * @sb contains the super_block structure for the filesystem. + * Check permission before obtaining filesystem statistics for the @mnt + * mountpoint. + * @dentry is a handle on the superblock for the filesystem. * Return 0 if permission is granted. * @sb_mount: * Check permission before an object specified by @dev_name is mounted on @@ -1127,7 +1127,7 @@ struct security_operations { int (*sb_copy_data)(struct file_system_type *type, void *orig, void *copy); int (*sb_kern_mount) (struct super_block *sb, void *data); - int (*sb_statfs) (struct super_block * sb); + int (*sb_statfs) (struct dentry *dentry); int (*sb_mount) (char *dev_name, struct nameidata * nd, char *type, unsigned long flags, void *data); int (*sb_check_sb) (struct vfsmount * mnt, struct nameidata * nd); @@ -1450,9 +1450,9 @@ static inline int security_sb_kern_mount (struct super_block *sb, void *data) return security_ops->sb_kern_mount (sb, data); } -static inline int security_sb_statfs (struct super_block *sb) +static inline int security_sb_statfs (struct dentry *dentry) { - return security_ops->sb_statfs (sb); + return security_ops->sb_statfs (dentry); } static inline int security_sb_mount (char *dev_name, struct nameidata *nd, @@ -2162,7 +2162,7 @@ static inline int security_sb_kern_mount (struct super_block *sb, void *data) return 0; } -static inline int security_sb_statfs (struct super_block *sb) +static inline int security_sb_statfs (struct dentry *dentry) { return 0; } -- cgit v1.1