linux-kernel - [PATCH 3.16 035/305] ext4: clean up error handling when orphan list is corrupted

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Message-ID: <lsq.1471110171.892439370@decadent.org.uk>
Date:	Sat, 13 Aug 2016 18:42:51 +0100
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "Theodore Ts'o" <tytso@....edu>
Subject: [PATCH 3.16 035/305] ext4: clean up error handling when orphan
 list is corrupted

3.16.37-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@....edu>

commit 7827a7f6ebfcb7f388dc47fddd48567a314701ba upstream.

Instead of just printing warning messages, if the orphan list is
corrupted, declare the file system is corrupted.  If there are any
reserved inodes in the orphaned inode list, declare the file system
corrupted and stop right away to avoid doing more potential damage to
the file system.

Signed-off-by: Theodore Ts'o <tytso@....edu>
[bwh: Backported to 3.16: leave error code as EIO]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 fs/ext4/ialloc.c | 49 ++++++++++++++++++++++---------------------------
 1 file changed, 22 insertions(+), 27 deletions(-)

--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -1090,22 +1090,19 @@ struct inode *ext4_orphan_get(struct sup
 	unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
 	ext4_group_t block_group;
 	int bit;
-	struct buffer_head *bitmap_bh;
+	struct buffer_head *bitmap_bh = NULL;
 	struct inode *inode = NULL;
-	long err = -EIO;
+	int err = -EIO;
 
-	/* Error cases - e2fsck has already cleaned up for us */
-	if (ino > max_ino) {
-		ext4_warning(sb, "bad orphan ino %lu!  e2fsck was run?", ino);
-		goto error;
-	}
+	if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
+		goto bad_orphan;
 
 	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 	if (!bitmap_bh) {
-		ext4_warning(sb, "inode bitmap error for orphan %lu", ino);
-		goto error;
+		ext4_error(sb, "inode bitmap error for orphan %lu", ino);
+		return (struct inode *) bitmap_bh;
 	}
 
 	/* Having the inode bit set should be a 100% indicator that this
@@ -1116,8 +1113,12 @@ struct inode *ext4_orphan_get(struct sup
 		goto bad_orphan;
 
 	inode = ext4_iget(sb, ino);
-	if (IS_ERR(inode))
-		goto iget_failed;
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		ext4_error(sb, "couldn't read orphan inode %lu (err %d)",
+			   ino, err);
+		return inode;
+	}
 
 	/*
 	 * If the orphans has i_nlinks > 0 then it should be able to
@@ -1134,29 +1135,25 @@ struct inode *ext4_orphan_get(struct sup
 	brelse(bitmap_bh);
 	return inode;
 
-iget_failed:
-	err = PTR_ERR(inode);
-	inode = NULL;
 bad_orphan:
-	ext4_warning(sb, "bad orphan inode %lu!  e2fsck was run?", ino);
-	printk(KERN_WARNING "ext4_test_bit(bit=%d, block=%llu) = %d\n",
-	       bit, (unsigned long long)bitmap_bh->b_blocknr,
-	       ext4_test_bit(bit, bitmap_bh->b_data));
-	printk(KERN_WARNING "inode=%p\n", inode);
+	ext4_error(sb, "bad orphan inode %lu", ino);
+	if (bitmap_bh)
+		printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",
+		       bit, (unsigned long long)bitmap_bh->b_blocknr,
+		       ext4_test_bit(bit, bitmap_bh->b_data));
 	if (inode) {
-		printk(KERN_WARNING "is_bad_inode(inode)=%d\n",
+		printk(KERN_ERR "is_bad_inode(inode)=%d\n",
 		       is_bad_inode(inode));
-		printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n",
+		printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",
 		       NEXT_ORPHAN(inode));
-		printk(KERN_WARNING "max_ino=%lu\n", max_ino);
-		printk(KERN_WARNING "i_nlink=%u\n", inode->i_nlink);
+		printk(KERN_ERR "max_ino=%lu\n", max_ino);
+		printk(KERN_ERR "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;
 		iput(inode);
 	}
 	brelse(bitmap_bh);
-error:
 	return ERR_PTR(err);
 }