diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-07-22 11:05:15 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-07-22 11:05:15 -0700 |
commit | f036d67c02b6f6966b0d45e9a16c9f2e7ede80a3 (patch) | |
tree | 5b8183940408ed9b79203a9055f1389422ce1050 | |
parent | bdd1d82e7d02bd2764a68a5cc54533dfc2ba452a (diff) | |
parent | bb5faa99f0ce40756ab7bbbce4f16c01ca5ebd5a (diff) |
Merge tag 'block-6.5-2023-07-21' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- Fix for loop regressions (Mauricio)
- Fix a potential stall with batched wakeups in sbitmap (David)
- Fix for stall with recursive plug flushes (Ross)
- Skip accounting of empty requests for blk-iocost (Chengming)
- Remove a dead field in struct blk_mq_hw_ctx (Chengming)
* tag 'block-6.5-2023-07-21' of git://git.kernel.dk/linux:
loop: do not enforce max_loop hard limit by (new) default
loop: deprecate autoloading callback loop_probe()
sbitmap: fix batching wakeup
blk-iocost: skip empty flush bio in iocost
blk-mq: delete dead struct blk_mq_hw_ctx->queued field
blk-mq: Fix stall due to recursive flush plug
-rw-r--r-- | block/blk-core.c | 3 | ||||
-rw-r--r-- | block/blk-iocost.c | 4 | ||||
-rw-r--r-- | block/blk-mq.c | 9 | ||||
-rw-r--r-- | drivers/block/loop.c | 40 | ||||
-rw-r--r-- | include/linux/blk-mq.h | 2 | ||||
-rw-r--r-- | lib/sbitmap.c | 15 |
6 files changed, 58 insertions, 15 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 99d8b9812b18..90de50082146 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1144,8 +1144,7 @@ void __blk_flush_plug(struct blk_plug *plug, bool from_schedule) { if (!list_empty(&plug->cb_list)) flush_plug_callbacks(plug, from_schedule); - if (!rq_list_empty(plug->mq_list)) - blk_mq_flush_plug_list(plug, from_schedule); + blk_mq_flush_plug_list(plug, from_schedule); /* * Unconditionally flush out cached requests, even if the unplug * event came from schedule. Since we know hold references to the diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 9dfcf540f400..dd64e2066f01 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2516,6 +2516,10 @@ static void calc_vtime_cost_builtin(struct bio *bio, struct ioc_gq *iocg, u64 seek_pages = 0; u64 cost = 0; + /* Can't calculate cost for empty bio */ + if (!bio->bi_iter.bi_size) + goto out; + switch (bio_op(bio)) { case REQ_OP_READ: coef_seqio = ioc->params.lcoefs[LCOEF_RSEQIO]; diff --git a/block/blk-mq.c b/block/blk-mq.c index d50b1d62a3d9..b04ff6f56926 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2754,7 +2754,14 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct request *rq; - if (rq_list_empty(plug->mq_list)) + /* + * We may have been called recursively midway through handling + * plug->mq_list via a schedule() in the driver's queue_rq() callback. + * To avoid mq_list changing under our feet, clear rq_count early and + * bail out specifically if rq_count is 0 rather than checking + * whether the mq_list is empty. + */ + if (plug->rq_count == 0) return; plug->rq_count = 0; diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 37511d2b2caf..637c5bda2387 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1775,14 +1775,43 @@ static const struct block_device_operations lo_fops = { /* * If max_loop is specified, create that many devices upfront. * This also becomes a hard limit. If max_loop is not specified, + * the default isn't a hard limit (as before commit 85c50197716c + * changed the default value from 0 for max_loop=0 reasons), just * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module * init time. Loop devices can be requested on-demand with the * /dev/loop-control interface, or be instantiated by accessing * a 'dead' device node. */ static int max_loop = CONFIG_BLK_DEV_LOOP_MIN_COUNT; -module_param(max_loop, int, 0444); + +#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD +static bool max_loop_specified; + +static int max_loop_param_set_int(const char *val, + const struct kernel_param *kp) +{ + int ret; + + ret = param_set_int(val, kp); + if (ret < 0) + return ret; + + max_loop_specified = true; + return 0; +} + +static const struct kernel_param_ops max_loop_param_ops = { + .set = max_loop_param_set_int, + .get = param_get_int, +}; + +module_param_cb(max_loop, &max_loop_param_ops, &max_loop, 0444); MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); +#else +module_param(max_loop, int, 0444); +MODULE_PARM_DESC(max_loop, "Initial number of loop devices"); +#endif + module_param(max_part, int, 0444); MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); @@ -2093,14 +2122,18 @@ static void loop_remove(struct loop_device *lo) put_disk(lo->lo_disk); } +#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD static void loop_probe(dev_t dev) { int idx = MINOR(dev) >> part_shift; - if (max_loop && idx >= max_loop) + if (max_loop_specified && max_loop && idx >= max_loop) return; loop_add(idx); } +#else +#define loop_probe NULL +#endif /* !CONFIG_BLOCK_LEGACY_AUTOLOAD */ static int loop_control_remove(int idx) { @@ -2281,6 +2314,9 @@ module_exit(loop_exit); static int __init max_loop_setup(char *str) { max_loop = simple_strtol(str, NULL, 0); +#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD + max_loop_specified = true; +#endif return 1; } diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index b96e00499f9e..495ca198775f 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -397,8 +397,6 @@ struct blk_mq_hw_ctx { */ struct blk_mq_tags *sched_tags; - /** @queued: Number of queued requests. */ - unsigned long queued; /** @run: Number of dispatched requests. */ unsigned long run; diff --git a/lib/sbitmap.c b/lib/sbitmap.c index eff4e42c425a..d0a5081dfd12 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -550,7 +550,7 @@ EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth); static void __sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) { - int i, wake_index; + int i, wake_index, woken; if (!atomic_read(&sbq->ws_active)) return; @@ -567,13 +567,12 @@ static void __sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) */ wake_index = sbq_index_inc(wake_index); - /* - * It is sufficient to wake up at least one waiter to - * guarantee forward progress. - */ - if (waitqueue_active(&ws->wait) && - wake_up_nr(&ws->wait, nr)) - break; + if (waitqueue_active(&ws->wait)) { + woken = wake_up_nr(&ws->wait, nr); + if (woken == nr) + break; + nr -= woken; + } } if (wake_index != atomic_read(&sbq->wake_index)) |