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Merge tag 'block-5.14-2021-08-27' of git://git.kernel.dk/linux-block

Browse Source 
Pull block fixes from Jens Axboe:

 - Revert the mq-deadline priority handling, it's causing serious
   performance regressions. While experimental patches exists to fix
   this up, it's too late to do so now. Revert it and re-do it properly
   for 5.15 instead.

 - Fix a NULL vs IS_ERR() regression in this release (Dan)

 - Fix a mq-deadline accounting regression in this release (Bart)

 - Mark cryptoloop as deprecated. It's broken and dm-crypt fully
   supports it, and it's actively intefering with loop. Plan on removal
   for 5.16 (Christoph)

* tag 'block-5.14-2021-08-27' of git://git.kernel.dk/linux-block:
  cryptoloop: add a deprecation warning
  pd: fix a NULL vs IS_ERR() check
  Revert "block/mq-deadline: Prioritize high-priority requests"
  mq-deadline: Fix request accounting
This commit is contained in:
Linus Torvalds
2021-08-27 16:08:29 -07:00
parent 6f18b82b41 222013f9ac
commit 64b4fc45be
4 changed files with 21 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
block/mq-deadline.c
View File

@@ -31,11 +31,6 @@
*/
static const int read_expire = HZ / 2; /* max time before a read is submitted. */
static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
/*
* Time after which to dispatch lower priority requests even if higher
* priority requests are pending.
*/
static const int aging_expire = 10 * HZ;
static const int writes_starved = 2; /* max times reads can starve a write */
static const int fifo_batch = 16; /* # of sequential requests treated as one
by the above parameters. For throughput. */
@@ -103,7 +98,6 @@ struct deadline_data {
int writes_starved;
int front_merges;
u32 async_depth;
int aging_expire;
spinlock_t lock;
spinlock_t zone_lock;
@@ -369,11 +363,10 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
/*
* deadline_dispatch_requests selects the best request according to
* read/write expire, fifo_batch, etc and with a start time <= @latest.
* read/write expire, fifo_batch, etc
*/
static struct request *__dd_dispatch_request(struct deadline_data *dd,
struct dd_per_prio *per_prio,
u64 latest_start_ns)
struct dd_per_prio *per_prio)
{
struct request *rq, *next_rq;
enum dd_data_dir data_dir;
@@ -385,8 +378,6 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd,
if (!list_empty(&per_prio->dispatch)) {
rq = list_first_entry(&per_prio->dispatch, struct request,
queuelist);
if (rq->start_time_ns > latest_start_ns)
return NULL;
list_del_init(&rq->queuelist);
goto done;
}
@@ -464,8 +455,6 @@ dispatch_find_request:
dd->batching = 0;
dispatch_request:
if (rq->start_time_ns > latest_start_ns)
return NULL;
/*
* rq is the selected appropriate request.
*/
@@ -494,32 +483,15 @@ done:
static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
{
struct deadline_data *dd = hctx->queue->elevator->elevator_data;
const u64 now_ns = ktime_get_ns();
struct request *rq = NULL;
struct request *rq;
enum dd_prio prio;
spin_lock(&dd->lock);
/*
* Start with dispatching requests whose deadline expired more than
* aging_expire jiffies ago.
*/
for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) {
rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns -
jiffies_to_nsecs(dd->aging_expire));
if (rq)
goto unlock;
}
/*
* Next, dispatch requests in priority order. Ignore lower priority
* requests if any higher priority requests are pending.
*/
for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now_ns);
if (rq || dd_queued(dd, prio))
rq = __dd_dispatch_request(dd, &dd->per_prio[prio]);
if (rq)
break;
}
unlock:
spin_unlock(&dd->lock);
return rq;
@@ -620,7 +592,6 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e)
dd->front_merges = 1;
dd->last_dir = DD_WRITE;
dd->fifo_batch = fifo_batch;
dd->aging_expire = aging_expire;
spin_lock_init(&dd->lock);
spin_lock_init(&dd->zone_lock);
@@ -711,6 +682,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
prio = ioprio_class_to_prio[ioprio_class];
dd_count(dd, inserted, prio);
rq->elv.priv[0] = (void *)(uintptr_t)1;
if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
blk_mq_free_requests(&free);
@@ -759,12 +731,10 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
spin_unlock(&dd->lock);
}
/*
* Nothing to do here. This is defined only to ensure that .finish_request
* method is called upon request completion.
*/
/* Callback from inside blk_mq_rq_ctx_init(). */
static void dd_prepare_request(struct request *rq)
{
rq->elv.priv[0] = NULL;
}
/*
@@ -791,7 +761,14 @@ static void dd_finish_request(struct request *rq)
const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
struct dd_per_prio *per_prio = &dd->per_prio[prio];
dd_count(dd, completed, prio);
/*
* The block layer core may call dd_finish_request() without having
* called dd_insert_requests(). Hence only update statistics for
* requests for which dd_insert_requests() has been called. See also
* blk_mq_request_bypass_insert().
*/
if (rq->elv.priv[0])
dd_count(dd, completed, prio);
if (blk_queue_is_zoned(q)) {
unsigned long flags;
@@ -836,7 +813,6 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \
#define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
SHOW_JIFFIES(deadline_aging_expire_show, dd->aging_expire);
SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
SHOW_INT(deadline_front_merges_show, dd->front_merges);
SHOW_INT(deadline_async_depth_show, dd->front_merges);
@@ -866,7 +842,6 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)
STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
STORE_JIFFIES(deadline_aging_expire_store, &dd->aging_expire, 0, INT_MAX);
STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
STORE_INT(deadline_async_depth_store, &dd->front_merges, 1, INT_MAX);
@@ -885,7 +860,6 @@ static struct elv_fs_entry deadline_attrs[] = {
DD_ATTR(front_merges),
DD_ATTR(async_depth),
DD_ATTR(fifo_batch),
DD_ATTR(aging_expire),
__ATTR_NULL
};

4
drivers/block/Kconfig
View File

@@ -213,7 +213,7 @@ config BLK_DEV_LOOP_MIN_COUNT
dynamically allocated with the /dev/loop-control interface.
config BLK_DEV_CRYPTOLOOP
tristate "Cryptoloop Support"
tristate "Cryptoloop Support (DEPRECATED)"
select CRYPTO
select CRYPTO_CBC
depends on BLK_DEV_LOOP
@@ -225,7 +225,7 @@ config BLK_DEV_CRYPTOLOOP
WARNING: This device is not safe for journaled file systems like
ext3 or Reiserfs. Please use the Device Mapper crypto module
instead, which can be configured to be on-disk compatible with the
cryptoloop device.
cryptoloop device. cryptoloop support will be removed in Linux 5.16.
source "drivers/block/drbd/Kconfig"

2
drivers/block/cryptoloop.c
View File

@@ -189,6 +189,8 @@ init_cryptoloop(void)
if (rc)
printk(KERN_ERR "cryptoloop: loop_register_transfer failed\n");
else
pr_warn("the cryptoloop driver has been deprecated and will be removed in in Linux 5.16\n");
return rc;
}

2
drivers/block/paride/pd.c
View File

@@ -892,7 +892,7 @@ static void pd_probe_drive(struct pd_unit *disk)
return;
p = blk_mq_alloc_disk(&disk->tag_set, disk);
if (!p) {
if (IS_ERR(p)) {
blk_mq_free_tag_set(&disk->tag_set);
return;
}