ext3: handle corrupted orphan list at mount

If the orphan node list includes valid, untruncatable nodes with nlink > 0
the ext3_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
ext3_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.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: printk warning fix]
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 24 insertions, 6 deletions

diff --git a/fs/ext3/ialloc.c b/fs/ext3/ialloc.c
index 77126821b2e9..47b678d73e7a 100644
--- a/fs/ext3/ialloc.c
+++ b/fs/ext3/ialloc.c
@@ -669,6 +669,14 @@ struct inode *ext3_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 && !ext3_can_truncate(inode))
+                goto bad_orphan;
+
         if (NEXT_ORPHAN(inode) > max_ino)
                 goto bad_orphan;
         brelse(bitmap_bh);
@@ -690,6 +698,7 @@ 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;
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 6ae4ecf3ce40..74b432fa166b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -2253,6 +2253,19 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
         }
 }
 
+int ext3_can_truncate(struct inode *inode)
+{
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return 0;
+        if (S_ISREG(inode->i_mode))
+                return 1;
+        if (S_ISDIR(inode->i_mode))
+                return 1;
+        if (S_ISLNK(inode->i_mode))
+                return !ext3_inode_is_fast_symlink(inode);
+        return 0;
+}
+
 /*
  * ext3_truncate()
  *
@@ -2297,12 +2310,7 @@ void ext3_truncate(struct inode *inode)
         unsigned blocksize = inode->i_sb->s_blocksize;
         struct page *page;
 
-        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-            S_ISLNK(inode->i_mode)))
-                return;
-        if (ext3_inode_is_fast_symlink(inode))
-                return;
-        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+        if (!ext3_can_truncate(inode))
                 return;
 
         /*
diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 36c540396377..80171ee89a22 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -832,6 +832,7 @@ extern void ext3_discard_reservation (struct inode *);
 extern void ext3_dirty_inode(struct inode *);
 extern int ext3_change_inode_journal_flag(struct inode *, int);
 extern int ext3_get_inode_loc(struct inode *, struct ext3_iloc *);
+extern int ext3_can_truncate(struct inode *inode);
 extern void ext3_truncate (struct inode *);
 extern void ext3_set_inode_flags(struct inode *);
 extern void ext3_get_inode_flags(struct ext3_inode_info *);