ext4: handle corrupted orphan list at mount

If the orphan node list includes valid, untruncatable nodes with nlink > 0
the ext4_orphan_cleanup loop which attempts to delete them will not do so,
causing it to loop forever. Fix by checking for such nodes in the
ext4_orphan_get function.

This patch fixes the second case (image hdb.20000009.softlockup.gz)
reported in http://bugzilla.kernel.org/show_bug.cgi?id=10882.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index c6efbab0c801..11cafe14aa27 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -817,6 +817,14 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
         if (IS_ERR(inode))
                 goto iget_failed;
 
+        /*
+         * If the orphans has i_nlinks > 0 then it should be able to be
+         * truncated, otherwise it won't be removed from the orphan list
+         * during processing and an infinite loop will result.
+         */
+        if (inode->i_nlink && !ext4_can_truncate(inode))
+                goto bad_orphan;
+
         if (NEXT_ORPHAN(inode) > max_ino)
                 goto bad_orphan;
         brelse(bitmap_bh);
@@ -838,6 +846,7 @@ bad_orphan:
                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
                        NEXT_ORPHAN(inode));
                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
+                printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
                 /* Avoid freeing blocks if we got a bad deleted inode */
                 if (inode->i_nlink == 0)
                         inode->i_blocks = 0;