ext4: fix block validity checks for journal inodes using indirect blocks

[ Upstream commit 170417c8c7bb2cbbdd949bf5c443c0c8f24a203b ]

Commit 345c0dbf3a30 ("ext4: protect journal inode's blocks using
block_validity") failed to add an exception for the journal inode in
ext4_check_blockref(), which is the function used by ext4_get_branch()
for indirect blocks.  This caused attempts to read from the ext3-style
journals to fail with:

[  848.968550] EXT4-fs error (device sdb7): ext4_get_branch:171: inode #8: block 30343695: comm jbd2/sdb7-8: invalid block

Fix this by adding the missing exception check.

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 9409b1e..cd7129b 100644 (file)
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -275,6 +275,11 @@ int ext4_check_blockref(const char *function, unsigned int line,
        __le32 *bref = p;
        unsigned int blk;
 
+       if (ext4_has_feature_journal(inode->i_sb) &&
+           (inode->i_ino ==
+            le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
+               return 0;
+
        while (bref < p+max) {
                blk = le32_to_cpu(*bref++);
                if (blk &&