2022-07-01 09:17:38

by Jingbo Xu

[permalink] [raw]
Subject: Re: [Linux-cachefs] [PATCH] fscache: Fix if condition in fscache_wait_on_volume_collision()



On 5/25/22 10:32 AM, Yue Hu wrote:
> After waiting for the volume to complete the acquisition with timeout,
> the if condition under which potential volume collision occurs should be
> acquire the volume is still pending rather than not pending so that we
> will continue to wait until the pending flag is cleared. Also, use the
> existing test pending wrapper directly instead of test_bit().
>
> Signed-off-by: Yue Hu <[email protected]>
> ---
> fs/fscache/volume.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c
> index 71d3a6d6d72c..f2009cc22002 100644
> --- a/fs/fscache/volume.c
> +++ b/fs/fscache/volume.c
> @@ -143,7 +143,7 @@ static void fscache_wait_on_volume_collision(struct fscache_volume *candidate,
> {
> wait_var_event_timeout(&candidate->flags,
> !fscache_is_acquire_pending(candidate), 20 * HZ);
> - if (!fscache_is_acquire_pending(candidate)) {
> + if (fscache_is_acquire_pending(candidate)) {
> pr_notice("Potential volume collision new=%08x old=%08x",
> candidate->debug_id, collidee_debug_id);
> fscache_stat(&fscache_n_volumes_collision);

Yeah, I also noticed that before.



> @@ -182,7 +182,7 @@ static bool fscache_hash_volume(struct fscache_volume *candidate)
> hlist_bl_add_head(&candidate->hash_link, h);
> hlist_bl_unlock(h);
>
> - if (test_bit(FSCACHE_VOLUME_ACQUIRE_PENDING, &candidate->flags))
> + if (fscache_is_acquire_pending(candidate))
> fscache_wait_on_volume_collision(candidate, collidee_debug_id);
> return true;
>

LGTM.

Reviewed-by: Jeffle Xu <[email protected]>

--
Thanks,
Jeffle