[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/nfs/dir.c b/fs/nfs/dir.c
index 7432f1a43f3d..26eecb86f9b0 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -843,7 +843,7 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
         nfs_inode_return_delegation(inode);
         if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
                 lock_kernel();
-                inode->i_nlink--;
+                drop_nlink(inode);
                 nfs_complete_unlink(dentry);
                 unlock_kernel();
         }
@@ -1401,7 +1401,7 @@ static int nfs_safe_remove(struct dentry *dentry)
                 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
                 /* The VFS may want to delete this inode */
                 if (error == 0)
-                        inode->i_nlink--;
+                        drop_nlink(inode);
                 nfs_mark_for_revalidate(inode);
                 nfs_end_data_update(inode);
         } else
@@ -1639,7 +1639,7 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                         goto out;
                 }
         } else
-                new_inode->i_nlink--;
+                drop_nlink(new_inode);
 
 go_ahead:
         /*