This is a note to let you know that I've just added the patch titled ext4: fix potential htree index checksum corruption to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-fix-potential-htree-index-checksum-corruption.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9ce493f642ed2f7280b3d1f4159d98ecc7efb0fa Author: Theodore Ts'o <tytso@xxxxxxx> Date: Thu Feb 4 00:05:20 2021 -0500 ext4: fix potential htree index checksum corruption [ Upstream commit b5776e7524afbd4569978ff790864755c438bba7 ] In the case where we need to do an interior node split, and immediately afterwards, we are unable to allocate a new directory leaf block due to ENOSPC, the directory index checksum's will not be filled in correctly (and indeed, will not be correctly journalled). This looks like a bug that was introduced when we added largedir support. The original code doesn't make any sense (and should have been caught in code review), but it was hidden because most of the time, the index node checksum will be set by do_split(). But if do_split bails out due to ENOSPC, then ext4_handle_dirty_dx_node() won't get called, and so the directory index checksum field will not get set, leading to: EXT4-fs error (device sdb): dx_probe:858: inode #6635543: block 4022: comm nfsd: Directory index failed checksum Google-Bug-Id: 176345532 Fixes: e08ac99fa2a2 ("ext4: add largedir feature") Cc: Artem Blagodarenko <artem.blagodarenko@xxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index f05ec9bfbf4fd..7f22487d502b5 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2405,11 +2405,10 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, (frame - 1)->bh); if (err) goto journal_error; - if (restart) { - err = ext4_handle_dirty_dx_node(handle, dir, - frame->bh); + err = ext4_handle_dirty_dx_node(handle, dir, + frame->bh); + if (err) goto journal_error; - } } else { struct dx_root *dxroot; memcpy((char *) entries2, (char *) entries,