From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaohua Li Subject: Re: [PATCH v2] md/bitmap: clear BITMAP_WRITE_ERROR bit before writing it to sb Date: Sun, 12 Nov 2017 19:57:41 -0800 Message-ID: <20171113035741.c2fwwluld2yuatgc@kernel.org> References: <20171106021125.40619-1-houtao1@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Hou Tao Cc: linux-raid@vger.kernel.org, neilb@suse.com List-Id: linux-raid.ids On Mon, Nov 13, 2017 at 10:18:14AM +0800, Hou Tao wrote: > Hi, > > Any comments ? already queued. > On 2017/11/6 10:11, Hou Tao wrote: > > For a RAID1 device using a file-based bitmap, if a bitmap write error > > occurs but the later writes succeed, it's possible both BITMAP_STALE > > and BITMAP_WRITE_ERROR bits will be written to the bitmap super block, > > the BITMAP_STALE bit will be handled properly and be cleared, but the > > BITMAP_WRITE_ERROR bit in sb->flags will make bitmap_create() to fail. > > > > So clear it to protect against the write failure-and-then-recovery case. > > > > Signed-off-by: Hou Tao > > > > --- > > v2: > > * clear the BITMAP_WRITE_ERROR bit before writing sb, not after > > reading sb > > v1: > > * http://www.spinics.net/lists/raid/msg59590.html > > --- > > drivers/md/bitmap.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c > > index d212163..30e503d 100644 > > --- a/drivers/md/bitmap.c > > +++ b/drivers/md/bitmap.c > > @@ -459,7 +459,11 @@ void bitmap_update_sb(struct bitmap *bitmap) > > /* rocking back to read-only */ > > bitmap->events_cleared = bitmap->mddev->events; > > sb->events_cleared = cpu_to_le64(bitmap->events_cleared); > > - sb->state = cpu_to_le32(bitmap->flags); > > + /* > > + * clear BITMAP_WRITE_ERROR bit to protect against the case that > > + * a bitmap write error occurred but the later writes succeeded. > > + */ > > + sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR)); > > /* Just in case these have been changed via sysfs: */ > > sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ); > > sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind); > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html