From 1f2030ff6e4958780af9e65a22c39fa8082f292b Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 6 Jun 2023 10:05:04 +0800 Subject: [PATCH] btrfs: scrub: respect the read-only flag during repair [BUG] With recent scrub rework, the scrub operation no longer respects the read-only flag passed by "-r" option of "btrfs scrub start" command. # mkfs.btrfs -f -d raid1 $dev1 $dev2 # mount $dev1 $mnt # xfs_io -f -d -c "pwrite -b 128K -S 0xaa 0 128k" $mnt/file # sync # xfs_io -c "pwrite -S 0xff $phy1 64k" $dev1 # xfs_io -c "pwrite -S 0xff $((phy2 + 65536)) 64k" $dev2 # mount $dev1 $mnt -o ro # btrfs scrub start -BrRd $mnt Scrub device $dev1 (id 1) done Scrub started: Tue Jun 6 09:59:14 2023 Status: finished Duration: 0:00:00 [...] corrected_errors: 16 <<< Still has corrupted sectors last_physical: 1372585984 Scrub device $dev2 (id 2) done Scrub started: Tue Jun 6 09:59:14 2023 Status: finished Duration: 0:00:00 [...] corrected_errors: 16 <<< Still has corrupted sectors last_physical: 1351614464 # btrfs scrub start -BrRd $mnt Scrub device $dev1 (id 1) done Scrub started: Tue Jun 6 10:00:17 2023 Status: finished Duration: 0:00:00 [...] corrected_errors: 0 <<< No more errors last_physical: 1372585984 Scrub device $dev2 (id 2) done [...] corrected_errors: 0 <<< No more errors last_physical: 1372585984 [CAUSE] In the newly reworked scrub code, repair is always submitted no matter if we're doing a read-only scrub. [FIX] Fix it by skipping the write submission if the scrub is a read-only one. Unfortunately for the report part, even for a read-only scrub we will still report it as corrected errors, as we know it's repairable, even we won't really submit the write. Fixes: e02ee89baa66 ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure") Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 7c66651..72c2c09 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -1730,7 +1730,7 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx) break; } } - } else { + } else if (!sctx->readonly) { for (int i = 0; i < nr_stripes; i++) { unsigned long repaired; -- 2.7.4