[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>

1 files changed, 5 insertions, 5 deletions

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 788b8b50dc4c..cdf73393f094 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -100,7 +100,7 @@ static int ocfs2_initialize_mem_caches(void);
 static void ocfs2_free_mem_caches(void);
 static void ocfs2_delete_osb(struct ocfs2_super *osb);
 
-static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf);
+static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf);
 
 static int ocfs2_sync_fs(struct super_block *sb, int wait);
 
@@ -857,7 +857,7 @@ static void ocfs2_put_super(struct super_block *sb)
         mlog_exit_void();
 }
 
-static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf)
+static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
         struct ocfs2_super *osb;
         u32 numbits, freebits;
@@ -866,9 +866,9 @@ static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf)
         struct buffer_head *bh = NULL;
         struct inode *inode = NULL;
 
-        mlog_entry("(%p, %p)\n", sb, buf);
+        mlog_entry("(%p, %p)\n", dentry->d_sb, buf);
 
-        osb = OCFS2_SB(sb);
+        osb = OCFS2_SB(dentry->d_sb);
 
         inode = ocfs2_get_system_file_inode(osb,
                                             GLOBAL_BITMAP_SYSTEM_INODE,
@@ -891,7 +891,7 @@ static int ocfs2_statfs(struct super_block *sb, struct kstatfs *buf)
         freebits = numbits - le32_to_cpu(bm_lock->id1.bitmap1.i_used);
 
         buf->f_type = OCFS2_SUPER_MAGIC;
-        buf->f_bsize = sb->s_blocksize;
+        buf->f_bsize = dentry->d_sb->s_blocksize;
         buf->f_namelen = OCFS2_MAX_FILENAME_LEN;
         buf->f_blocks = ((sector_t) numbits) *
                         (osb->s_clustersize >> osb->sb->s_blocksize_bits);