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-rw-r--r--drivers/md/raid5.c168
-rw-r--r--drivers/md/raid5.h1
2 files changed, 166 insertions, 3 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 81c02d63440..74dcf19cfe6 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -547,6 +547,8 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
rw = WRITE_FUA;
else
rw = WRITE;
+ if (test_and_clear_bit(R5_Discard, &sh->dev[i].flags))
+ rw |= REQ_DISCARD;
} else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
rw = READ;
else if (test_and_clear_bit(R5_WantReplace,
@@ -1170,8 +1172,13 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
set_bit(R5_WantFUA, &dev->flags);
if (wbi->bi_rw & REQ_SYNC)
set_bit(R5_SyncIO, &dev->flags);
- tx = async_copy_data(1, wbi, dev->page,
- dev->sector, tx);
+ if (wbi->bi_rw & REQ_DISCARD) {
+ memset(page_address(dev->page), 0,
+ STRIPE_SECTORS << 9);
+ set_bit(R5_Discard, &dev->flags);
+ } else
+ tx = async_copy_data(1, wbi, dev->page,
+ dev->sector, tx);
wbi = r5_next_bio(wbi, dev->sector);
}
}
@@ -1237,6 +1244,20 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ for (i = 0; i < sh->disks; i++) {
+ if (pd_idx == i)
+ continue;
+ if (!test_bit(R5_Discard, &sh->dev[i].flags))
+ break;
+ }
+ if (i >= sh->disks) {
+ atomic_inc(&sh->count);
+ memset(page_address(sh->dev[pd_idx].page), 0,
+ STRIPE_SECTORS << 9);
+ set_bit(R5_Discard, &sh->dev[pd_idx].flags);
+ ops_complete_reconstruct(sh);
+ return;
+ }
/* check if prexor is active which means only process blocks
* that are part of a read-modify-write (written)
*/
@@ -1281,10 +1302,28 @@ ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
{
struct async_submit_ctl submit;
struct page **blocks = percpu->scribble;
- int count;
+ int count, i;
pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
+ for (i = 0; i < sh->disks; i++) {
+ if (sh->pd_idx == i || sh->qd_idx == i)
+ continue;
+ if (!test_bit(R5_Discard, &sh->dev[i].flags))
+ break;
+ }
+ if (i >= sh->disks) {
+ atomic_inc(&sh->count);
+ memset(page_address(sh->dev[sh->pd_idx].page), 0,
+ STRIPE_SECTORS << 9);
+ memset(page_address(sh->dev[sh->qd_idx].page), 0,
+ STRIPE_SECTORS << 9);
+ set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
+ set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
+ ops_complete_reconstruct(sh);
+ return;
+ }
+
count = set_syndrome_sources(blocks, sh);
atomic_inc(&sh->count);
@@ -4067,6 +4106,88 @@ static void release_stripe_plug(struct mddev *mddev,
release_stripe(sh);
}
+static void make_discard_request(struct mddev *mddev, struct bio *bi)
+{
+ struct r5conf *conf = mddev->private;
+ sector_t logical_sector, last_sector;
+ struct stripe_head *sh;
+ int remaining;
+ int stripe_sectors;
+
+ if (mddev->reshape_position != MaxSector)
+ /* Skip discard while reshape is happening */
+ return;
+
+ logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
+ last_sector = bi->bi_sector + (bi->bi_size>>9);
+
+ bi->bi_next = NULL;
+ bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
+
+ stripe_sectors = conf->chunk_sectors *
+ (conf->raid_disks - conf->max_degraded);
+ logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
+ stripe_sectors);
+ sector_div(last_sector, stripe_sectors);
+
+ logical_sector *= conf->chunk_sectors;
+ last_sector *= conf->chunk_sectors;
+
+ for (; logical_sector < last_sector;
+ logical_sector += STRIPE_SECTORS) {
+ DEFINE_WAIT(w);
+ int d;
+ again:
+ sh = get_active_stripe(conf, logical_sector, 0, 0, 0);
+ prepare_to_wait(&conf->wait_for_overlap, &w,
+ TASK_UNINTERRUPTIBLE);
+ spin_lock_irq(&sh->stripe_lock);
+ for (d = 0; d < conf->raid_disks; d++) {
+ if (d == sh->pd_idx || d == sh->qd_idx)
+ continue;
+ if (sh->dev[d].towrite || sh->dev[d].toread) {
+ set_bit(R5_Overlap, &sh->dev[d].flags);
+ spin_unlock_irq(&sh->stripe_lock);
+ release_stripe(sh);
+ schedule();
+ goto again;
+ }
+ }
+ finish_wait(&conf->wait_for_overlap, &w);
+ for (d = 0; d < conf->raid_disks; d++) {
+ if (d == sh->pd_idx || d == sh->qd_idx)
+ continue;
+ sh->dev[d].towrite = bi;
+ set_bit(R5_OVERWRITE, &sh->dev[d].flags);
+ raid5_inc_bi_active_stripes(bi);
+ }
+ spin_unlock_irq(&sh->stripe_lock);
+ if (conf->mddev->bitmap) {
+ for (d = 0;
+ d < conf->raid_disks - conf->max_degraded;
+ d++)
+ bitmap_startwrite(mddev->bitmap,
+ sh->sector,
+ STRIPE_SECTORS,
+ 0);
+ sh->bm_seq = conf->seq_flush + 1;
+ set_bit(STRIPE_BIT_DELAY, &sh->state);
+ }
+
+ set_bit(STRIPE_HANDLE, &sh->state);
+ clear_bit(STRIPE_DELAYED, &sh->state);
+ if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+ atomic_inc(&conf->preread_active_stripes);
+ release_stripe_plug(mddev, sh);
+ }
+
+ remaining = raid5_dec_bi_active_stripes(bi);
+ if (remaining == 0) {
+ md_write_end(mddev);
+ bio_endio(bi, 0);
+ }
+}
+
static void make_request(struct mddev *mddev, struct bio * bi)
{
struct r5conf *conf = mddev->private;
@@ -4089,6 +4210,11 @@ static void make_request(struct mddev *mddev, struct bio * bi)
chunk_aligned_read(mddev,bi))
return;
+ if (unlikely(bi->bi_rw & REQ_DISCARD)) {
+ make_discard_request(mddev, bi);
+ return;
+ }
+
logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
bi->bi_next = NULL;
@@ -5362,6 +5488,7 @@ static int run(struct mddev *mddev)
if (mddev->queue) {
int chunk_size;
+ bool discard_supported = true;
/* read-ahead size must cover two whole stripes, which
* is 2 * (datadisks) * chunksize where 'n' is the
* number of raid devices
@@ -5381,13 +5508,48 @@ static int run(struct mddev *mddev)
blk_queue_io_min(mddev->queue, chunk_size);
blk_queue_io_opt(mddev->queue, chunk_size *
(conf->raid_disks - conf->max_degraded));
+ /*
+ * We can only discard a whole stripe. It doesn't make sense to
+ * discard data disk but write parity disk
+ */
+ stripe = stripe * PAGE_SIZE;
+ mddev->queue->limits.discard_alignment = stripe;
+ mddev->queue->limits.discard_granularity = stripe;
+ /*
+ * unaligned part of discard request will be ignored, so can't
+ * guarantee discard_zerors_data
+ */
+ mddev->queue->limits.discard_zeroes_data = 0;
rdev_for_each(rdev, mddev) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->new_data_offset << 9);
+ /*
+ * discard_zeroes_data is required, otherwise data
+ * could be lost. Consider a scenario: discard a stripe
+ * (the stripe could be inconsistent if
+ * discard_zeroes_data is 0); write one disk of the
+ * stripe (the stripe could be inconsistent again
+ * depending on which disks are used to calculate
+ * parity); the disk is broken; The stripe data of this
+ * disk is lost.
+ */
+ if (!blk_queue_discard(bdev_get_queue(rdev->bdev)) ||
+ !bdev_get_queue(rdev->bdev)->
+ limits.discard_zeroes_data)
+ discard_supported = false;
}
+
+ if (discard_supported &&
+ mddev->queue->limits.max_discard_sectors >= stripe &&
+ mddev->queue->limits.discard_granularity >= stripe)
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
+ mddev->queue);
+ else
+ queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
+ mddev->queue);
}
return 0;
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index a9fc24901ed..18b2c4a8a1f 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -298,6 +298,7 @@ enum r5dev_flags {
R5_WantReplace, /* We need to update the replacement, we have read
* data in, and now is a good time to write it out.
*/
+ R5_Discard, /* Discard the stripe */
};
/*
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 13:07:14 +0000