summaryrefslogtreecommitdiffstats
path: root/drivers/md/raid5.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c209
1 files changed, 157 insertions, 52 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c574cf5efb5..968dacaced6 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -63,6 +63,7 @@
#define STRIPE_SHIFT (PAGE_SHIFT - 9)
#define STRIPE_SECTORS (STRIPE_SIZE>>9)
#define IO_THRESHOLD 1
+#define BYPASS_THRESHOLD 1
#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
#define HASH_MASK (NR_HASH - 1)
@@ -398,6 +399,7 @@ static void ops_run_io(struct stripe_head *sh)
might_sleep();
+ set_bit(STRIPE_IO_STARTED, &sh->state);
for (i = disks; i--; ) {
int rw;
struct bio *bi;
@@ -433,7 +435,7 @@ static void ops_run_io(struct stripe_head *sh)
bi->bi_bdev = rdev->bdev;
pr_debug("%s: for %llu schedule op %ld on disc %d\n",
- __FUNCTION__, (unsigned long long)sh->sector,
+ __func__, (unsigned long long)sh->sector,
bi->bi_rw, i);
atomic_inc(&sh->count);
bi->bi_sector = sh->sector + rdev->data_offset;
@@ -520,7 +522,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
raid5_conf_t *conf = sh->raid_conf;
int i;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
/* clear completed biofills */
@@ -569,7 +571,7 @@ static void ops_run_biofill(struct stripe_head *sh)
raid5_conf_t *conf = sh->raid_conf;
int i;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = sh->disks; i--; ) {
@@ -600,7 +602,7 @@ static void ops_complete_compute5(void *stripe_head_ref)
int target = sh->ops.target;
struct r5dev *tgt = &sh->dev[target];
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
set_bit(R5_UPTODATE, &tgt->flags);
@@ -625,7 +627,7 @@ ops_run_compute5(struct stripe_head *sh, unsigned long pending)
int i;
pr_debug("%s: stripe %llu block: %d\n",
- __FUNCTION__, (unsigned long long)sh->sector, target);
+ __func__, (unsigned long long)sh->sector, target);
BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
for (i = disks; i--; )
@@ -653,7 +655,7 @@ static void ops_complete_prexor(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
set_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
@@ -670,7 +672,7 @@ ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
/* existing parity data subtracted */
struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
@@ -699,7 +701,7 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
*/
int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
@@ -744,7 +746,7 @@ static void ops_complete_postxor(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
@@ -757,7 +759,7 @@ static void ops_complete_write(void *stripe_head_ref)
struct stripe_head *sh = stripe_head_ref;
int disks = sh->disks, i, pd_idx = sh->pd_idx;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
@@ -787,7 +789,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
unsigned long flags;
dma_async_tx_callback callback;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
/* check if prexor is active which means only process blocks
@@ -837,7 +839,7 @@ static void ops_complete_check(void *stripe_head_ref)
struct stripe_head *sh = stripe_head_ref;
int pd_idx = sh->pd_idx;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
if (test_and_clear_bit(STRIPE_OP_MOD_DMA_CHECK, &sh->ops.pending) &&
@@ -859,7 +861,7 @@ static void ops_run_check(struct stripe_head *sh)
int count = 0, pd_idx = sh->pd_idx, i;
struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
- pr_debug("%s: stripe %llu\n", __FUNCTION__,
+ pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
@@ -1260,8 +1262,8 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
}
set_bit(Faulty, &rdev->flags);
printk (KERN_ALERT
- "raid5: Disk failure on %s, disabling device."
- " Operation continuing on %d devices\n",
+ "raid5: Disk failure on %s, disabling device.\n"
+ "raid5: Operation continuing on %d devices.\n",
bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
}
}
@@ -1720,6 +1722,9 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
locked++;
}
}
+ if (locked + 1 == disks)
+ if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
+ atomic_inc(&sh->raid_conf->pending_full_writes);
} else {
BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
@@ -1759,7 +1764,7 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
locked++;
pr_debug("%s: stripe %llu locked: %d pending: %lx\n",
- __FUNCTION__, (unsigned long long)sh->sector,
+ __func__, (unsigned long long)sh->sector,
locked, sh->ops.pending);
return locked;
@@ -1947,6 +1952,9 @@ handle_requests_to_failed_array(raid5_conf_t *conf, struct stripe_head *sh,
STRIPE_SECTORS, 0, 0);
}
+ if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
+ if (atomic_dec_and_test(&conf->pending_full_writes))
+ md_wakeup_thread(conf->mddev->thread);
}
/* __handle_issuing_new_read_requests5 - returns 0 if there are no more disks
@@ -2149,6 +2157,10 @@ static void handle_completed_write_requests(raid5_conf_t *conf,
0);
}
}
+
+ if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
+ if (atomic_dec_and_test(&conf->pending_full_writes))
+ md_wakeup_thread(conf->mddev->thread);
}
static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
@@ -2333,6 +2345,9 @@ static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
s->locked++;
set_bit(R5_Wantwrite, &sh->dev[i].flags);
}
+ if (s->locked == disks)
+ if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
+ atomic_inc(&conf->pending_full_writes);
/* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
set_bit(STRIPE_INSYNC, &sh->state);
@@ -2348,25 +2363,15 @@ static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
struct stripe_head_state *s, int disks)
{
+ int canceled_check = 0;
+
set_bit(STRIPE_HANDLE, &sh->state);
- /* Take one of the following actions:
- * 1/ start a check parity operation if (uptodate == disks)
- * 2/ finish a check parity operation and act on the result
- * 3/ skip to the writeback section if we previously
- * initiated a recovery operation
- */
- if (s->failed == 0 &&
- !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
- if (!test_and_set_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
- BUG_ON(s->uptodate != disks);
- clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
- sh->ops.count++;
- s->uptodate--;
- } else if (
- test_and_clear_bit(STRIPE_OP_CHECK, &sh->ops.complete)) {
- clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
- clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
+ /* complete a check operation */
+ if (test_and_clear_bit(STRIPE_OP_CHECK, &sh->ops.complete)) {
+ clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
+ clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
+ if (s->failed == 0) {
if (sh->ops.zero_sum_result == 0)
/* parity is correct (on disc,
* not in buffer any more)
@@ -2391,7 +2396,8 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
s->uptodate++;
}
}
- }
+ } else
+ canceled_check = 1; /* STRIPE_INSYNC is not set */
}
/* check if we can clear a parity disk reconstruct */
@@ -2404,12 +2410,28 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
}
+ /* start a new check operation if there are no failures, the stripe is
+ * not insync, and a repair is not in flight
+ */
+ if (s->failed == 0 &&
+ !test_bit(STRIPE_INSYNC, &sh->state) &&
+ !test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
+ if (!test_and_set_bit(STRIPE_OP_CHECK, &sh->ops.pending)) {
+ BUG_ON(s->uptodate != disks);
+ clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
+ sh->ops.count++;
+ s->uptodate--;
+ }
+ }
+
/* Wait for check parity and compute block operations to complete
- * before write-back
+ * before write-back. If a failure occurred while the check operation
+ * was in flight we need to cycle this stripe through handle_stripe
+ * since the parity block may not be uptodate
*/
- if (!test_bit(STRIPE_INSYNC, &sh->state) &&
- !test_bit(STRIPE_OP_CHECK, &sh->ops.pending) &&
- !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) {
+ if (!canceled_check && !test_bit(STRIPE_INSYNC, &sh->state) &&
+ !test_bit(STRIPE_OP_CHECK, &sh->ops.pending) &&
+ !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) {
struct r5dev *dev;
/* either failed parity check, or recovery is happening */
if (s->failed == 0)
@@ -3087,6 +3109,8 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
else
continue;
+ set_bit(STRIPE_IO_STARTED, &sh->state);
+
bi = &sh->dev[i].req;
bi->bi_rw = rw;
@@ -3157,7 +3181,7 @@ static void raid5_activate_delayed(raid5_conf_t *conf)
clear_bit(STRIPE_DELAYED, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
- list_add_tail(&sh->lru, &conf->handle_list);
+ list_add_tail(&sh->lru, &conf->hold_list);
}
} else
blk_plug_device(conf->mddev->queue);
@@ -3435,6 +3459,58 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
}
}
+/* __get_priority_stripe - get the next stripe to process
+ *
+ * Full stripe writes are allowed to pass preread active stripes up until
+ * the bypass_threshold is exceeded. In general the bypass_count
+ * increments when the handle_list is handled before the hold_list; however, it
+ * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
+ * stripe with in flight i/o. The bypass_count will be reset when the
+ * head of the hold_list has changed, i.e. the head was promoted to the
+ * handle_list.
+ */
+static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
+{
+ struct stripe_head *sh;
+
+ pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
+ __func__,
+ list_empty(&conf->handle_list) ? "empty" : "busy",
+ list_empty(&conf->hold_list) ? "empty" : "busy",
+ atomic_read(&conf->pending_full_writes), conf->bypass_count);
+
+ if (!list_empty(&conf->handle_list)) {
+ sh = list_entry(conf->handle_list.next, typeof(*sh), lru);
+
+ if (list_empty(&conf->hold_list))
+ conf->bypass_count = 0;
+ else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
+ if (conf->hold_list.next == conf->last_hold)
+ conf->bypass_count++;
+ else {
+ conf->last_hold = conf->hold_list.next;
+ conf->bypass_count -= conf->bypass_threshold;
+ if (conf->bypass_count < 0)
+ conf->bypass_count = 0;
+ }
+ }
+ } else if (!list_empty(&conf->hold_list) &&
+ ((conf->bypass_threshold &&
+ conf->bypass_count > conf->bypass_threshold) ||
+ atomic_read(&conf->pending_full_writes) == 0)) {
+ sh = list_entry(conf->hold_list.next,
+ typeof(*sh), lru);
+ conf->bypass_count -= conf->bypass_threshold;
+ if (conf->bypass_count < 0)
+ conf->bypass_count = 0;
+ } else
+ return NULL;
+
+ list_del_init(&sh->lru);
+ atomic_inc(&sh->count);
+ BUG_ON(atomic_read(&sh->count) != 1);
+ return sh;
+}
static int make_request(struct request_queue *q, struct bio * bi)
{
@@ -3907,7 +3983,6 @@ static void raid5d(mddev_t *mddev)
handled = 0;
spin_lock_irq(&conf->device_lock);
while (1) {
- struct list_head *first;
struct bio *bio;
if (conf->seq_flush != conf->seq_write) {
@@ -3929,17 +4004,12 @@ static void raid5d(mddev_t *mddev)
handled++;
}
- if (list_empty(&conf->handle_list)) {
+ sh = __get_priority_stripe(conf);
+
+ if (!sh) {
async_tx_issue_pending_all();
break;
}
-
- first = conf->handle_list.next;
- sh = list_entry(first, struct stripe_head, lru);
-
- list_del_init(first);
- atomic_inc(&sh->count);
- BUG_ON(atomic_read(&sh->count)!= 1);
spin_unlock_irq(&conf->device_lock);
handled++;
@@ -3971,15 +4041,13 @@ static ssize_t
raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
{
raid5_conf_t *conf = mddev_to_conf(mddev);
- char *end;
- int new;
+ unsigned long new;
if (len >= PAGE_SIZE)
return -EINVAL;
if (!conf)
return -ENODEV;
- new = simple_strtoul(page, &end, 10);
- if (!*page || (*end && *end != '\n') )
+ if (strict_strtoul(page, 10, &new))
return -EINVAL;
if (new <= 16 || new > 32768)
return -EINVAL;
@@ -4004,6 +4072,40 @@ raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
raid5_store_stripe_cache_size);
static ssize_t
+raid5_show_preread_threshold(mddev_t *mddev, char *page)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ if (conf)
+ return sprintf(page, "%d\n", conf->bypass_threshold);
+ else
+ return 0;
+}
+
+static ssize_t
+raid5_store_preread_threshold(mddev_t *mddev, const char *page, size_t len)
+{
+ raid5_conf_t *conf = mddev_to_conf(mddev);
+ unsigned long new;
+ if (len >= PAGE_SIZE)
+ return -EINVAL;
+ if (!conf)
+ return -ENODEV;
+
+ if (strict_strtoul(page, 10, &new))
+ return -EINVAL;
+ if (new > conf->max_nr_stripes)
+ return -EINVAL;
+ conf->bypass_threshold = new;
+ return len;
+}
+
+static struct md_sysfs_entry
+raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
+ S_IRUGO | S_IWUSR,
+ raid5_show_preread_threshold,
+ raid5_store_preread_threshold);
+
+static ssize_t
stripe_cache_active_show(mddev_t *mddev, char *page)
{
raid5_conf_t *conf = mddev_to_conf(mddev);
@@ -4019,6 +4121,7 @@ raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
static struct attribute *raid5_attrs[] = {
&raid5_stripecache_size.attr,
&raid5_stripecache_active.attr,
+ &raid5_preread_bypass_threshold.attr,
NULL,
};
static struct attribute_group raid5_attrs_group = {
@@ -4123,12 +4226,14 @@ static int run(mddev_t *mddev)
init_waitqueue_head(&conf->wait_for_stripe);
init_waitqueue_head(&conf->wait_for_overlap);
INIT_LIST_HEAD(&conf->handle_list);
+ INIT_LIST_HEAD(&conf->hold_list);
INIT_LIST_HEAD(&conf->delayed_list);
INIT_LIST_HEAD(&conf->bitmap_list);
INIT_LIST_HEAD(&conf->inactive_list);
atomic_set(&conf->active_stripes, 0);
atomic_set(&conf->preread_active_stripes, 0);
atomic_set(&conf->active_aligned_reads, 0);
+ conf->bypass_threshold = BYPASS_THRESHOLD;
pr_debug("raid5: run(%s) called.\n", mdname(mddev));
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-14 20:31:58 +0000