[PATCH] r/o bind mounts: unlink: monitor i_nlink

When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.

We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.

So, add a little helper function to do the decrements.  We'll tie into it in a
bit to note when i_nlink hits zero.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index c61710e49c62..c76d427e027b 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -20,7 +20,7 @@
 #include <linux/quotaops.h>
 
 #define INC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) { i->i_nlink++; if (i->i_nlink >= REISERFS_LINK_MAX) i->i_nlink=1; }
-#define DEC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) i->i_nlink--;
+#define DEC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) drop_nlink(i);
 
 // directory item contains array of entry headers. This performs
 // binary search through that array
@@ -994,7 +994,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
                 inode->i_nlink = 1;
         }
 
-        inode->i_nlink--;
+        drop_nlink(inode);
 
         /*
          * we schedule before doing the add_save_link call, save the link
@@ -1475,7 +1475,7 @@ static int reiserfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                 if (S_ISDIR(new_dentry_inode->i_mode)) {
                         new_dentry_inode->i_nlink = 0;
                 } else {
-                        new_dentry_inode->i_nlink--;
+                        drop_nlink(new_dentry_inode);
                 }
                 new_dentry_inode->i_ctime = ctime;
                 savelink = new_dentry_inode->i_nlink;