From b5776e7524afbd4569978ff790864755c438bba7 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 4 Feb 2021 00:05:20 -0500 Subject: [PATCH] ext4: fix potential htree index checksum corruption 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 Signed-off-by: Theodore Ts'o --- fs/ext4/namei.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index a6e28b4b5a95..115762180801 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2411,11 +2411,10 @@ again: (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,