Messages in this thread Patch in this message | | | Subject | [patch resend] vfs: fix vfs_rename_dir for FS_RENAME_DOES_D_MOVE filesystems | From | Miklos Szeredi <> | Date | Wed, 30 Jul 2008 12:26:23 +0200 |
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From: Miklos Szeredi <mszeredi@suse.cz>
vfs_rename_dir() doesn't properly account for filesystems with FS_RENAME_DOES_D_MOVE. If new_dentry has a target inode attached, it unhashes the new_dentry prior to the rename() iop and rehashes it after, but doesn't account for the possibility that rename() may have swapped {old,new}_dentry. For FS_RENAME_DOES_D_MOVE filesystems, it rehashes new_dentry (now the old renamed-from name, which d_move() expected to go away), such that a subsequent lookup will find it.
This was caught by the recently posted POSIX fstest suite, rename/10.t test 62 (and others) on ceph.
The bug was introduced by: commit 349457ccf2592c14bdf13b6706170ae2e94931b1 "[PATCH] Allow file systems to manually d_move() inside of ->rename()"
Fix by not rehashing the new dentry. Rehashing used to be needed by d_move() but isn't anymore.
Reported-by: Sage Weil <sage@newdream.net> CC: Zach Brown <zach.brown@oracle.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- fs/namei.c | 2 -- 1 file changed, 2 deletions(-)
Index: linux-2.6/fs/namei.c =================================================================== --- linux-2.6.orig/fs/namei.c 2008-07-29 21:28:55.000000000 +0200 +++ linux-2.6/fs/namei.c 2008-07-29 21:36:50.000000000 +0200 @@ -2542,8 +2542,6 @@ static int vfs_rename_dir(struct inode * if (!error) target->i_flags |= S_DEAD; mutex_unlock(&target->i_mutex); - if (d_unhashed(new_dentry)) - d_rehash(new_dentry); dput(new_dentry); } if (!error)
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