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| author | Song Liu <songliubraving@fb.com> | 2017-05-12 02:03:44 +0200 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-05-12 07:14:40 +0200 |
| commit | 5ddf0440a1a28f00f69ed2e093476bab3b60c2c3 (patch) | |
| tree | 33a11155215f93288b40d300839a58f3c13b7f8c /drivers/md/raid5.c | |
| parent | md/r5cache: gracefully handle journal device errors for writeback mode (diff) | |
| download | linux-5ddf0440a1a28f00f69ed2e093476bab3b60c2c3.tar.xz linux-5ddf0440a1a28f00f69ed2e093476bab3b60c2c3.zip | |
md/r5cache: handle sync with data in write back cache
Currently, sync of raid456 array cannot make progress when hitting
data in writeback r5cache.
This patch fixes this issue by flushing cached data of the stripe
before processing the sync request. This is achived by:
1. In handle_stripe(), do not set STRIPE_SYNCING if the stripe is
in write back cache;
2. In r5c_try_caching_write(), handle the stripe in sync with write
through;
3. In do_release_stripe(), make stripe in sync write out and send
it to the state machine.
Shaohua: explictly set STRIPE_HANDLE after write out completed
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 0ac57a925606..9c4f7659f8b1 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -233,11 +233,15 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh, if (test_bit(R5_InJournal, &sh->dev[i].flags)) injournal++; /* - * When quiesce in r5c write back, set STRIPE_HANDLE for stripes with - * data in journal, so they are not released to cached lists + * In the following cases, the stripe cannot be released to cached + * lists. Therefore, we make the stripe write out and set + * STRIPE_HANDLE: + * 1. when quiesce in r5c write back; + * 2. when resync is requested fot the stripe. */ - if (conf->quiesce && r5c_is_writeback(conf->log) && - !test_bit(STRIPE_HANDLE, &sh->state) && injournal != 0) { + if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) || + (conf->quiesce && r5c_is_writeback(conf->log) && + !test_bit(STRIPE_HANDLE, &sh->state) && injournal != 0)) { if (test_bit(STRIPE_R5C_CACHING, &sh->state)) r5c_make_stripe_write_out(sh); set_bit(STRIPE_HANDLE, &sh->state); @@ -4656,8 +4660,13 @@ static void handle_stripe(struct stripe_head *sh) if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) { spin_lock(&sh->stripe_lock); - /* Cannot process 'sync' concurrently with 'discard' */ - if (!test_bit(STRIPE_DISCARD, &sh->state) && + /* + * Cannot process 'sync' concurrently with 'discard'. + * Flush data in r5cache before 'sync'. + */ + if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) && + !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state) && + !test_bit(STRIPE_DISCARD, &sh->state) && test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) { set_bit(STRIPE_SYNCING, &sh->state); clear_bit(STRIPE_INSYNC, &sh->state); |