Re: [PATCH] f2fs: prevent meta updates while checkpoint is in progress

From: Sahitya Tummala
Date: Tue Mar 31 2020 - 05:06:33 EST


On Mon, Mar 30, 2020 at 08:54:19PM -0700, Jaegeuk Kim wrote:
> On 03/26, Sahitya Tummala wrote:
> > allocate_segment_for_resize() can cause metapage updates if
> > it requires to change the current node/data segments for resizing.
> > Stop these meta updates when there is a checkpoint already
> > in progress to prevent inconsistent CP data.
>
> I'd prefer to use f2fs_lock_op() in bigger coverage.

Do you mean to cover the entire free_segment_range() function within
f2fs_lock_op()? Please clarify.

Thanks,

>
> >
> > Signed-off-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
> > ---
> > fs/f2fs/gc.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 5bca560..6122bad 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -1399,8 +1399,10 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start,
> > int err = 0;
> >
> > /* Move out cursegs from the target range */
> > + f2fs_lock_op(sbi);
> > for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++)
> > allocate_segment_for_resize(sbi, type, start, end);
> > + f2fs_unlock_op(sbi);
> >
> > /* do GC to move out valid blocks in the range */
> > for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
> > --
> > Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
> > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

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