ext4: don't perform block validity checks on the journal inode

[ Upstream commit 0a944e8a6c66ca04c7afbaa17e22bf208a8b37f0 ]

Since the journal inode is already checked when we added it to the
block validity's system zone, if we check it again, we'll just trigger
a failure.

This was causing failures like this:

[   53.897001] EXT4-fs error (device sda): ext4_find_extent:909: inode
#8: comm jbd2/sda-8: pblk 121667583 bad header/extent: invalid extent entries - magic f30a, entries 8, max 340(340), depth 0(0)
[   53.931430] jbd2_journal_bmap: journal block not found at offset 49 on sda-8
[   53.938480] Aborting journal on device sda-8.

... but only if the system was under enough memory pressure that
logical->physical mapping for the journal inode gets pushed out of the
extent cache.  (This is why it wasn't noticed earlier.)

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Dan Rue <dan.rue@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 45aea79..00bf0b6 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -518,10 +518,14 @@ __read_extent_tree_block(const char *function, unsigned int line,
        }
        if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
                return bh;
-       err = __ext4_ext_check(function, line, inode,
-                              ext_block_hdr(bh), depth, pblk);
-       if (err)
-               goto errout;
+       if (!ext4_has_feature_journal(inode->i_sb) ||
+           (inode->i_ino !=
+            le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) {
+               err = __ext4_ext_check(function, line, inode,
+                                      ext_block_hdr(bh), depth, pblk);
+               if (err)
+                       goto errout;
+       }
        set_buffer_verified(bh);
        /*
         * If this is a leaf block, cache all of its entries