[PATCH] r/o bind mounts: clean up OCFS2 nlink handling

OCFS2 does some operations on i_nlink, then reverts them if some of its
operations fail to complete.  This does not fit in well with the
drop_nlink() logic where we expect i_nlink to stay at zero once it gets
there.

So, delay all of the nlink operations until we're sure that the operations
have completed.  Also, introduce a small helper to check whether an inode
has proper "unlinkable" i_nlink counts no matter whether it is a directory
or regular inode.

This patch is broken out from the others because it does contain some
logical changes.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: 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>

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 8c370a3..259155f 100644 (file)
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -795,11 +795,23 @@ static int ocfs2_remote_dentry_delete(struct dentry *dentry)
        return ret;
 }
 
+static inline int inode_is_unlinkable(struct inode *inode)
+{
+       if (S_ISDIR(inode->i_mode)) {
+               if (inode->i_nlink == 2)
+                       return 1;
+               return 0;
+       }
+
+       if (inode->i_nlink == 1)
+               return 1;
+       return 0;
+}
+
 static int ocfs2_unlink(struct inode *dir,
                        struct dentry *dentry)
 {
        int status;
-       unsigned int saved_nlink = 0;
        struct inode *inode = dentry->d_inode;
        struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
        u64 blkno;
@@ -874,16 +886,6 @@ static int ocfs2_unlink(struct inode *dir,
                }
        }
 
-       /* There are still a few steps left until we can consider the
-        * unlink to have succeeded. Save off nlink here before
-        * modification so we can set it back in case we hit an issue
-        * before commit. */
-       saved_nlink = inode->i_nlink;
-       if (S_ISDIR(inode->i_mode))
-               inode->i_nlink = 0;
-       else
-               inode->i_nlink--;
-
        status = ocfs2_remote_dentry_delete(dentry);
        if (status < 0) {
                /* This vote should succeed under all normal
@@ -892,7 +894,7 @@ static int ocfs2_unlink(struct inode *dir,
                goto leave;
        }
 
-       if (!inode->i_nlink) {
+       if (inode_is_unlinkable(inode)) {
                status = ocfs2_prepare_orphan_dir(osb, handle, inode,
                                                  orphan_name,
                                                  &orphan_entry_bh);
@@ -919,7 +921,7 @@ static int ocfs2_unlink(struct inode *dir,
 
        fe = (struct ocfs2_dinode *) fe_bh->b_data;
 
-       if (!inode->i_nlink) {
+       if (inode_is_unlinkable(inode)) {
                status = ocfs2_orphan_add(osb, handle, inode, fe, orphan_name,
                                          orphan_entry_bh);
                if (status < 0) {
@@ -935,10 +937,10 @@ static int ocfs2_unlink(struct inode *dir,
                goto leave;
        }
 
-       /* We can set nlink on the dinode now. clear the saved version
-        * so that it doesn't get set later. */
+       if (S_ISDIR(inode->i_mode))
+               drop_nlink(inode);
+       drop_nlink(inode);
        fe->i_links_count = cpu_to_le16(inode->i_nlink);
-       saved_nlink = 0;
 
        status = ocfs2_journal_dirty(handle, fe_bh);
        if (status < 0) {
@@ -947,7 +949,7 @@ static int ocfs2_unlink(struct inode *dir,
        }
 
        if (S_ISDIR(inode->i_mode)) {
-               dir->i_nlink--;
+               drop_nlink(dir);
                status = ocfs2_mark_inode_dirty(handle, dir,
                                                parent_node_bh);
                if (status < 0) {
@@ -957,9 +959,6 @@ static int ocfs2_unlink(struct inode *dir,
        }
 
 leave:
-       if (status < 0 && saved_nlink)
-               inode->i_nlink = saved_nlink;
-
        if (handle)
                ocfs2_commit_trans(handle);