On 11.04.19 г. 8:30 ч., Qu Wenruo wrote: > [BUG] > Since commit "btrfs-progs: disk-io: Flush to ensure super block write is > FUA" mkfs-tests/017 will fail like: > > ====== RUN MUSTFAIL /home/adam/btrfs-progs/mkfs.btrfs -K -f /dev/mapper/btrfs-progs-thin-vol > ERROR: failed to write super block for devid 1: flush error: Input/output error > disk-io.c:1810: write_all_supers: BUG_ON `ret` triggered, value -5 > /home/adam/btrfs-progs/mkfs.btrfs(+0x1e5c1)[0x557a2c83e5c1] > /home/adam/btrfs-progs/mkfs.btrfs(+0x1e65f)[0x557a2c83e65f] > /home/adam/btrfs-progs/mkfs.btrfs(write_all_supers+0x1ce)[0x557a2c843a8a] > /home/adam/btrfs-progs/mkfs.btrfs(write_ctree_super+0x12d)[0x557a2c843be2] > /home/adam/btrfs-progs/mkfs.btrfs(btrfs_commit_transaction+0x250)[0x557a2c887c56] > /home/adam/btrfs-progs/mkfs.btrfs(+0xc0b1)[0x557a2c82c0b1] > /home/adam/btrfs-progs/mkfs.btrfs(main+0x1049)[0x557a2c82e929] > /usr/lib/libc.so.6(__libc_start_main+0xf3)[0x7f6689e99223] > /home/adam/btrfs-progs/mkfs.btrfs(_start+0x2e)[0x557a2c82b86e] > failed (expected): /home/adam/btrfs-progs/mkfs.btrfs -K -f /dev/mapper/btrfs-progs-thin-vol > > [CAUSE] > Just one BUG_ON() in write_all_supers(). > > [FIX] > Just remove the BUG_ON(). Callers of write_all_supers() are already > checking the return value. Not entirely true. btrfs_commit_transaction calls write_ctree_super and ignores the retval (which is the retval of write_all_supers). I wonder if there is anything more that could be done in this context though? I'm in favor of removing the BUG_ON though. If there isn't anything else to do in btrfs_commit_transaction: Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> > > Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> > --- > disk-io.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/disk-io.c b/disk-io.c > index 10550151c5bb..3517de3d8672 100644 > --- a/disk-io.c > +++ b/disk-io.c > @@ -1807,7 +1807,8 @@ int write_all_supers(struct btrfs_fs_info *fs_info) > btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN); > > ret = write_dev_supers(fs_info, sb, dev); > - BUG_ON(ret); > + if (ret < 0) > + return ret; > } > return 0; > } >
