From 322316385dde5cd879e682bcb598c56d0659fb60 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Sun, 4 Jan 2009 02:43:40 -0500 Subject: block: Allow empty integrity profile Allow a block device to allocate and register an integrity profile without providing a template. This allows DM to preallocate a profile to avoid deadlocks during table reconfiguration. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-integrity.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'block') diff --git a/block/blk-integrity.c b/block/blk-integrity.c index 61a8e2f8fdd0..91fa8e06b6a5 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -309,24 +309,24 @@ static struct kobj_type integrity_ktype = { /** * blk_integrity_register - Register a gendisk as being integrity-capable * @disk: struct gendisk pointer to make integrity-aware - * @template: integrity profile + * @template: optional integrity profile to register * * Description: When a device needs to advertise itself as being able * to send/receive integrity metadata it must use this function to * register the capability with the block layer. The template is a * blk_integrity struct with values appropriate for the underlying - * hardware. See Documentation/block/data-integrity.txt. + * hardware. If template is NULL the new profile is allocated but + * not filled out. See Documentation/block/data-integrity.txt. */ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template) { struct blk_integrity *bi; BUG_ON(disk == NULL); - BUG_ON(template == NULL); if (disk->integrity == NULL) { bi = kmem_cache_alloc(integrity_cachep, - GFP_KERNEL | __GFP_ZERO); + GFP_KERNEL | __GFP_ZERO); if (!bi) return -1; @@ -346,13 +346,16 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template) bi = disk->integrity; /* Use the provided profile as template */ - bi->name = template->name; - bi->generate_fn = template->generate_fn; - bi->verify_fn = template->verify_fn; - bi->tuple_size = template->tuple_size; - bi->set_tag_fn = template->set_tag_fn; - bi->get_tag_fn = template->get_tag_fn; - bi->tag_size = template->tag_size; + if (template != NULL) { + bi->name = template->name; + bi->generate_fn = template->generate_fn; + bi->verify_fn = template->verify_fn; + bi->tuple_size = template->tuple_size; + bi->set_tag_fn = template->set_tag_fn; + bi->get_tag_fn = template->get_tag_fn; + bi->tag_size = template->tag_size; + } else + bi->name = "unsupported"; return 0; } -- cgit v1.2.3 From f48fc4d32e24c0b6a18aad30305d819bcc68c049 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 5 Jan 2009 10:17:25 +0100 Subject: block: get rid of the manual directory counting in blktrace It can result in a stuck blktrace system, if --kill is used. Signed-off-by: Jens Axboe --- block/blktrace.c | 72 +++++++++++++++++--------------------------------------- 1 file changed, 21 insertions(+), 51 deletions(-) (limited to 'block') diff --git a/block/blktrace.c b/block/blktrace.c index b0a2cae886db..39cc3bfe56e4 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -187,59 +187,12 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, static struct dentry *blk_tree_root; static DEFINE_MUTEX(blk_tree_mutex); -static unsigned int root_users; - -static inline void blk_remove_root(void) -{ - if (blk_tree_root) { - debugfs_remove(blk_tree_root); - blk_tree_root = NULL; - } -} - -static void blk_remove_tree(struct dentry *dir) -{ - mutex_lock(&blk_tree_mutex); - debugfs_remove(dir); - if (--root_users == 0) - blk_remove_root(); - mutex_unlock(&blk_tree_mutex); -} - -static struct dentry *blk_create_tree(const char *blk_name) -{ - struct dentry *dir = NULL; - int created = 0; - - mutex_lock(&blk_tree_mutex); - - if (!blk_tree_root) { - blk_tree_root = debugfs_create_dir("block", NULL); - if (!blk_tree_root) - goto err; - created = 1; - } - - dir = debugfs_create_dir(blk_name, blk_tree_root); - if (dir) - root_users++; - else { - /* Delete root only if we created it */ - if (created) - blk_remove_root(); - } - -err: - mutex_unlock(&blk_tree_mutex); - return dir; -} static void blk_trace_cleanup(struct blk_trace *bt) { - relay_close(bt->rchan); debugfs_remove(bt->msg_file); debugfs_remove(bt->dropped_file); - blk_remove_tree(bt->dir); + relay_close(bt->rchan); free_percpu(bt->sequence); free_percpu(bt->msg_data); kfree(bt); @@ -346,7 +299,18 @@ static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, static int blk_remove_buf_file_callback(struct dentry *dentry) { + struct dentry *parent = dentry->d_parent; debugfs_remove(dentry); + + /* + * this will fail for all but the last file, but that is ok. what we + * care about is the top level buts->name directory going away, when + * the last trace file is gone. Then we don't have to rmdir() that + * manually on trace stop, so it nicely solves the issue with + * force killing of running traces. + */ + + debugfs_remove(parent); return 0; } @@ -404,7 +368,15 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, goto err; ret = -ENOENT; - dir = blk_create_tree(buts->name); + + if (!blk_tree_root) { + blk_tree_root = debugfs_create_dir("block", NULL); + if (!blk_tree_root) + return -ENOMEM; + } + + dir = debugfs_create_dir(buts->name, blk_tree_root); + if (!dir) goto err; @@ -458,8 +430,6 @@ probe_err: atomic_dec(&blk_probes_ref); mutex_unlock(&blk_probe_mutex); err: - if (dir) - blk_remove_tree(dir); if (bt) { if (bt->msg_file) debugfs_remove(bt->msg_file); -- cgit v1.2.3 From 1308835ffffe6d61ad1f48c5c381c9cc47f683ec Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Wed, 7 Jan 2009 12:22:39 +0100 Subject: block: export SSD/non-rotational queue flag through sysfs For some devices (i.e. CFA ATA) we can't reliably detect whether the device is of rotational or non-rotational type so we need to leave the final decision about this setting to the user-space. As a bonus do a minor CodingStyle fixup in queue_nomerges_store(). Suggested-by: Alan Cox Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index a29cb788e408..b538ab8dbbd1 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -130,6 +130,27 @@ static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) return queue_var_show(max_hw_sectors_kb, (page)); } +static ssize_t queue_nonrot_show(struct request_queue *q, char *page) +{ + return queue_var_show(!blk_queue_nonrot(q), page); +} + +static ssize_t queue_nonrot_store(struct request_queue *q, const char *page, + size_t count) +{ + unsigned long nm; + ssize_t ret = queue_var_store(&nm, page, count); + + spin_lock_irq(q->queue_lock); + if (nm) + queue_flag_clear(QUEUE_FLAG_NONROT, q); + else + queue_flag_set(QUEUE_FLAG_NONROT, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + static ssize_t queue_nomerges_show(struct request_queue *q, char *page) { return queue_var_show(blk_queue_nomerges(q), page); @@ -146,8 +167,8 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, queue_flag_set(QUEUE_FLAG_NOMERGES, q); else queue_flag_clear(QUEUE_FLAG_NOMERGES, q); - spin_unlock_irq(q->queue_lock); + return ret; } @@ -210,6 +231,12 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = { .show = queue_hw_sector_size_show, }; +static struct queue_sysfs_entry queue_nonrot_entry = { + .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, + .show = queue_nonrot_show, + .store = queue_nonrot_store, +}; + static struct queue_sysfs_entry queue_nomerges_entry = { .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, .show = queue_nomerges_show, @@ -229,6 +256,7 @@ static struct attribute *default_attrs[] = { &queue_max_sectors_entry.attr, &queue_iosched_entry.attr, &queue_hw_sector_size_entry.attr, + &queue_nonrot_entry.attr, &queue_nomerges_entry.attr, &queue_rq_affinity_entry.attr, NULL, -- cgit v1.2.3 From 213d9417fec62ef4c3675621b9364a667954d4dd Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 6 Jan 2009 09:16:05 +0100 Subject: block: seperate bio/request unplug and sync bits Signed-off-by: Jens Axboe --- block/blk-core.c | 5 ++++- include/linux/bio.h | 18 +++++++++++------- include/linux/blkdev.h | 2 ++ 3 files changed, 17 insertions(+), 8 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index a824e49c0d0a..9e2e86fb78b8 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1125,6 +1125,8 @@ void init_request_from_bio(struct request *req, struct bio *bio) if (bio_sync(bio)) req->cmd_flags |= REQ_RW_SYNC; + if (bio_unplug(bio)) + req->cmd_flags |= REQ_UNPLUG; if (bio_rw_meta(bio)) req->cmd_flags |= REQ_RW_META; @@ -1141,6 +1143,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) int el_ret, nr_sectors; const unsigned short prio = bio_prio(bio); const int sync = bio_sync(bio); + const int unplug = bio_unplug(bio); int rw_flags; nr_sectors = bio_sectors(bio); @@ -1244,7 +1247,7 @@ get_rq: blk_plug_device(q); add_request(q, req); out: - if (sync || blk_queue_nonrot(q)) + if (unplug || blk_queue_nonrot(q)) __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); return 0; diff --git a/include/linux/bio.h b/include/linux/bio.h index 5175aa3103c6..f53568c5852e 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -163,12 +163,15 @@ struct bio { #define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */ #define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */ #define BIO_RW_BARRIER 2 -#define BIO_RW_SYNC 3 -#define BIO_RW_META 4 -#define BIO_RW_DISCARD 5 -#define BIO_RW_FAILFAST_DEV 6 -#define BIO_RW_FAILFAST_TRANSPORT 7 -#define BIO_RW_FAILFAST_DRIVER 8 +#define BIO_RW_SYNCIO 3 +#define BIO_RW_UNPLUG 4 +#define BIO_RW_META 5 +#define BIO_RW_DISCARD 6 +#define BIO_RW_FAILFAST_DEV 7 +#define BIO_RW_FAILFAST_TRANSPORT 8 +#define BIO_RW_FAILFAST_DRIVER 9 + +#define BIO_RW_SYNC (BIO_RW_SYNCIO | BIO_RW_UNPLUG) /* * upper 16 bits of bi_rw define the io priority of this bio @@ -194,7 +197,8 @@ struct bio { #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx) #define bio_sectors(bio) ((bio)->bi_size >> 9) #define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER)) -#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC)) +#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNCIO)) +#define bio_unplug(bio) ((bio)->bi_rw & (1 << BIO_RW_UNPLUG)) #define bio_failfast_dev(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV)) #define bio_failfast_transport(bio) \ ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT)) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 044467ef7b11..75426e4b8cdf 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -108,6 +108,7 @@ enum rq_flag_bits { __REQ_RW_META, /* metadata io request */ __REQ_COPY_USER, /* contains copies of user pages */ __REQ_INTEGRITY, /* integrity metadata has been remapped */ + __REQ_UNPLUG, /* unplug queue on submission */ __REQ_NR_BITS, /* stops here */ }; @@ -134,6 +135,7 @@ enum rq_flag_bits { #define REQ_RW_META (1 << __REQ_RW_META) #define REQ_COPY_USER (1 << __REQ_COPY_USER) #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) +#define REQ_UNPLUG (1 << __REQ_UNPLUG) #define BLK_MAX_CDB 16 -- cgit v1.2.3 From dbdac9b71dff5d27885f82eb2cfca310861fdf9e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 13 Jan 2009 15:27:32 +0100 Subject: block: Fix documentation for blkdev_issue_flush() Signed-off-by: "Theodore Ts'o" Signed-off-by: Jens Axboe --- block/blk-barrier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block') diff --git a/block/blk-barrier.c b/block/blk-barrier.c index 8eba4e43bb0c..f7dae57e6cab 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -302,7 +302,7 @@ static void bio_end_empty_barrier(struct bio *bio, int err) * Description: * Issue a flush for the block device in question. Caller can supply * room for storing the error offset in case of a flush error, if they - * wish to. Caller must run wait_for_completion() on its own. + * wish to. */ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector) { -- cgit v1.2.3 From cec0707e40ae25794b5a2de7b7f03c51961f80d9 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 13 Jan 2009 15:28:32 +0100 Subject: block: silently error an unsupported barrier bio This fixes a "regression" from 2.6.28, where the barrier probes that file systems may do would trigger additional end request warnings in dmesg. Signed-off-by: Jens Axboe --- block/blk-core.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index 9e2e86fb78b8..ae75c047f45d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1451,6 +1451,11 @@ static inline void __generic_make_request(struct bio *bio) err = -EOPNOTSUPP; goto end_io; } + if (bio_barrier(bio) && bio_has_data(bio) && + (q->next_ordered == QUEUE_ORDERED_NONE)) { + err = -EOPNOTSUPP; + goto end_io; + } ret = q->make_request_fn(q, bio); } while (ret); -- cgit v1.2.3 From bc58ba9468d94d62c56ab9b47173583ec140b165 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 23 Jan 2009 10:54:44 +0100 Subject: block: add sysfs file for controlling io stats accounting This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe --- block/blk-core.c | 90 ++++++++++++++++++++++++++++++-------------------- block/blk-sysfs.c | 28 ++++++++++++++++ include/linux/blkdev.h | 6 ++++ 3 files changed, 88 insertions(+), 36 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index ae75c047f45d..ca69f3d94100 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -64,11 +64,12 @@ static struct workqueue_struct *kblockd_workqueue; static void drive_stat_acct(struct request *rq, int new_io) { + struct gendisk *disk = rq->rq_disk; struct hd_struct *part; int rw = rq_data_dir(rq); int cpu; - if (!blk_fs_request(rq) || !rq->rq_disk) + if (!blk_fs_request(rq) || !disk || !blk_queue_io_stat(disk->queue)) return; cpu = part_stat_lock(); @@ -599,8 +600,7 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) q->request_fn = rfn; q->prep_rq_fn = NULL; q->unplug_fn = generic_unplug_device; - q->queue_flags = (1 << QUEUE_FLAG_CLUSTER | - 1 << QUEUE_FLAG_STACKABLE); + q->queue_flags = QUEUE_FLAG_DEFAULT; q->queue_lock = lock; blk_queue_segment_boundary(q, BLK_SEG_BOUNDARY_MASK); @@ -1663,6 +1663,55 @@ void blkdev_dequeue_request(struct request *req) } EXPORT_SYMBOL(blkdev_dequeue_request); +static void blk_account_io_completion(struct request *req, unsigned int bytes) +{ + struct gendisk *disk = req->rq_disk; + + if (!disk || !blk_queue_io_stat(disk->queue)) + return; + + if (blk_fs_request(req)) { + const int rw = rq_data_dir(req); + struct hd_struct *part; + int cpu; + + cpu = part_stat_lock(); + part = disk_map_sector_rcu(req->rq_disk, req->sector); + part_stat_add(cpu, part, sectors[rw], bytes >> 9); + part_stat_unlock(); + } +} + +static void blk_account_io_done(struct request *req) +{ + struct gendisk *disk = req->rq_disk; + + if (!disk || !blk_queue_io_stat(disk->queue)) + return; + + /* + * Account IO completion. bar_rq isn't accounted as a normal + * IO on queueing nor completion. Accounting the containing + * request is enough. + */ + if (blk_fs_request(req) && req != &req->q->bar_rq) { + unsigned long duration = jiffies - req->start_time; + const int rw = rq_data_dir(req); + struct hd_struct *part; + int cpu; + + cpu = part_stat_lock(); + part = disk_map_sector_rcu(disk, req->sector); + + part_stat_inc(cpu, part, ios[rw]); + part_stat_add(cpu, part, ticks[rw], duration); + part_round_stats(cpu, part); + part_dec_in_flight(part); + + part_stat_unlock(); + } +} + /** * __end_that_request_first - end I/O on a request * @req: the request being processed @@ -1698,16 +1747,7 @@ static int __end_that_request_first(struct request *req, int error, (unsigned long long)req->sector); } - if (blk_fs_request(req) && req->rq_disk) { - const int rw = rq_data_dir(req); - struct hd_struct *part; - int cpu; - - cpu = part_stat_lock(); - part = disk_map_sector_rcu(req->rq_disk, req->sector); - part_stat_add(cpu, part, sectors[rw], nr_bytes >> 9); - part_stat_unlock(); - } + blk_account_io_completion(req, nr_bytes); total_bytes = bio_nbytes = 0; while ((bio = req->bio) != NULL) { @@ -1787,8 +1827,6 @@ static int __end_that_request_first(struct request *req, int error, */ static void end_that_request_last(struct request *req, int error) { - struct gendisk *disk = req->rq_disk; - if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); @@ -1800,27 +1838,7 @@ static void end_that_request_last(struct request *req, int error) blk_delete_timer(req); - /* - * Account IO completion. bar_rq isn't accounted as a normal - * IO on queueing nor completion. Accounting the containing - * request is enough. - */ - if (disk && blk_fs_request(req) && req != &req->q->bar_rq) { - unsigned long duration = jiffies - req->start_time; - const int rw = rq_data_dir(req); - struct hd_struct *part; - int cpu; - - cpu = part_stat_lock(); - part = disk_map_sector_rcu(disk, req->sector); - - part_stat_inc(cpu, part, ios[rw]); - part_stat_add(cpu, part, ticks[rw], duration); - part_round_stats(cpu, part); - part_dec_in_flight(part); - - part_stat_unlock(); - } + blk_account_io_done(req); if (req->end_io) req->end_io(req, error); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index b538ab8dbbd1..e29ddfc73cf4 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -197,6 +197,27 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) return ret; } +static ssize_t queue_iostats_show(struct request_queue *q, char *page) +{ + return queue_var_show(blk_queue_io_stat(q), page); +} + +static ssize_t queue_iostats_store(struct request_queue *q, const char *page, + size_t count) +{ + unsigned long stats; + ssize_t ret = queue_var_store(&stats, page, count); + + spin_lock_irq(q->queue_lock); + if (stats) + queue_flag_set(QUEUE_FLAG_IO_STAT, q); + else + queue_flag_clear(QUEUE_FLAG_IO_STAT, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + static struct queue_sysfs_entry queue_requests_entry = { .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, .show = queue_requests_show, @@ -249,6 +270,12 @@ static struct queue_sysfs_entry queue_rq_affinity_entry = { .store = queue_rq_affinity_store, }; +static struct queue_sysfs_entry queue_iostats_entry = { + .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, + .show = queue_iostats_show, + .store = queue_iostats_store, +}; + static struct attribute *default_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -259,6 +286,7 @@ static struct attribute *default_attrs[] = { &queue_nonrot_entry.attr, &queue_nomerges_entry.attr, &queue_rq_affinity_entry.attr, + &queue_iostats_entry.attr, NULL, }; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 75426e4b8cdf..d08c4b8219a6 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -451,6 +451,11 @@ struct request_queue #define QUEUE_FLAG_STACKABLE 13 /* supports request stacking */ #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ +#define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ + +#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ + (1 << QUEUE_FLAG_CLUSTER) | \ + 1 << QUEUE_FLAG_STACKABLE) static inline int queue_is_locked(struct request_queue *q) { @@ -567,6 +572,7 @@ enum { #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) +#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags) #define blk_queue_flushing(q) ((q)->ordseq) #define blk_queue_stackable(q) \ test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags) -- cgit v1.2.3 From 3a9a3f6cc55418dd1525e636dccbbe13c394f652 Mon Sep 17 00:00:00 2001 From: Divyesh Shah Date: Fri, 30 Jan 2009 12:46:41 +0100 Subject: cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice This patch adds the ability to pre-empt an ongoing BE timeslice when a RT request is waiting for the current timeslice to complete. This reduces the wait time to disk for RT requests from an upper bound of 4 (current value of cfq_quantum) to 1 disk request. Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt() and retested. Latency(secs) for the RT task when doing sequential reads from 10G file. | only RT | RT + BE | RT + BE + this patch small (512 byte) reads | 143 | 163 | 145 large (1Mb) reads | 142 | 158 | 146 Signed-off-by: Divyesh Shah Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index e8525fa72823..664ebfd092ec 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -84,6 +84,11 @@ struct cfq_data { */ struct cfq_rb_root service_tree; unsigned int busy_queues; + /* + * Used to track any pending rt requests so we can pre-empt current + * non-RT cfqq in service when this value is non-zero. + */ + unsigned int busy_rt_queues; int rq_in_driver; int sync_flight; @@ -562,6 +567,8 @@ static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(cfq_cfqq_on_rr(cfqq)); cfq_mark_cfqq_on_rr(cfqq); cfqd->busy_queues++; + if (cfq_class_rt(cfqq)) + cfqd->busy_rt_queues++; cfq_resort_rr_list(cfqd, cfqq); } @@ -581,6 +588,8 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(!cfqd->busy_queues); cfqd->busy_queues--; + if (cfq_class_rt(cfqq)) + cfqd->busy_rt_queues--; } /* @@ -1004,6 +1013,20 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) if (cfq_slice_used(cfqq)) goto expire; + /* + * If we have a RT cfqq waiting, then we pre-empt the current non-rt + * cfqq. + */ + if (!cfq_class_rt(cfqq) && cfqd->busy_rt_queues) { + /* + * We simulate this as cfqq timed out so that it gets to bank + * the remaining of its time slice. + */ + cfq_log_cfqq(cfqd, cfqq, "preempt"); + cfq_slice_expired(cfqd, 1); + goto new_queue; + } + /* * The active queue has requests and isn't expired, allow it to * dispatch. @@ -1067,6 +1090,13 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (RB_EMPTY_ROOT(&cfqq->sort_list)) break; + /* + * If there is a non-empty RT cfqq waiting for current + * cfqq's timeslice to complete, pre-empt this cfqq + */ + if (!cfq_class_rt(cfqq) && cfqd->busy_rt_queues) + break; + } while (dispatched < max_dispatch); /* @@ -1801,6 +1831,12 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, if (rq_is_meta(rq) && !cfqq->meta_pending) return 1; + /* + * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. + */ + if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) + return 1; + if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) return 0; @@ -1870,7 +1906,8 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, /* * not the active queue - expire current slice if it is * idle and has expired it's mean thinktime or this new queue - * has some old slice time left and is of higher priority + * has some old slice time left and is of higher priority or + * this new queue is RT and the current one is BE */ cfq_preempt_queue(cfqd, cfqq); cfq_mark_cfqq_must_dispatch(cfqq); -- cgit v1.2.3 From fb8ec18c316d869271137c97320dbfd2def56569 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 2 Feb 2009 08:42:32 +0100 Subject: block: fix oops in blk_queue_io_stat() Some initial probe requests don't have disk->queue mapped yet, so we can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in blk_do_io_stat(). Signed-off-by: Jens Axboe --- block/blk-core.c | 6 +++--- block/blk.h | 8 ++++++++ 2 files changed, 11 insertions(+), 3 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index ca69f3d94100..29bcfac6c688 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -69,7 +69,7 @@ static void drive_stat_acct(struct request *rq, int new_io) int rw = rq_data_dir(rq); int cpu; - if (!blk_fs_request(rq) || !disk || !blk_queue_io_stat(disk->queue)) + if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue)) return; cpu = part_stat_lock(); @@ -1667,7 +1667,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes) { struct gendisk *disk = req->rq_disk; - if (!disk || !blk_queue_io_stat(disk->queue)) + if (!disk || !blk_do_io_stat(disk->queue)) return; if (blk_fs_request(req)) { @@ -1686,7 +1686,7 @@ static void blk_account_io_done(struct request *req) { struct gendisk *disk = req->rq_disk; - if (!disk || !blk_queue_io_stat(disk->queue)) + if (!disk || !blk_do_io_stat(disk->queue)) return; /* diff --git a/block/blk.h b/block/blk.h index 6e1ed40534e9..0dce92c37496 100644 --- a/block/blk.h +++ b/block/blk.h @@ -108,4 +108,12 @@ static inline int blk_cpu_to_group(int cpu) #endif } +static inline int blk_do_io_stat(struct request_queue *q) +{ + if (q) + return blk_queue_io_stat(q); + + return 0; +} + #endif -- cgit v1.2.3 From c1c201200a359cf3b6e2e36a4236cdca77a3cd8e Mon Sep 17 00:00:00 2001 From: Boaz Harrosh Date: Tue, 3 Feb 2009 07:47:29 +0100 Subject: bsg: Fix sense buffer bug in SG_IO When submitting requests via SG_IO, which does a sync io, a bsg_command is not allocated. So an in-Kernel sense_buffer was not set. However when calling blk_execute_rq() with no sense buffer one is provided from the stack. Now bsg at blk_complete_sgv4_hdr_rq() would check if rq->sense_len and a sense was requested by sg_io_v4 the rq->sense was copy_user() back, but by now it is already mangled stack memory. I have fixed that by forcing a sense_buffer when calling bsg_map_hdr(). The bsg_command->sense is provided in the write/read path like before, and on-the-stack buffer is provided when doing SG_IO. I have also fixed a dprintk message to print rq->errors in hex because of the scsi bit-field use of this member. For other block devices it does not matter anyway. Signed-off-by: Boaz Harrosh Acked-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- block/bsg.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'block') diff --git a/block/bsg.c b/block/bsg.c index d414bb5607e8..0ce8806dd0c1 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -244,7 +244,8 @@ bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw) * map sg_io_v4 to a request. */ static struct request * -bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm) +bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm, + u8 *sense) { struct request_queue *q = bd->queue; struct request *rq, *next_rq = NULL; @@ -306,6 +307,10 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm) if (ret) goto out; } + + rq->sense = sense; + rq->sense_len = 0; + return rq; out: if (rq->cmd != rq->__cmd) @@ -348,9 +353,6 @@ static void bsg_rq_end_io(struct request *rq, int uptodate) static void bsg_add_command(struct bsg_device *bd, struct request_queue *q, struct bsg_command *bc, struct request *rq) { - rq->sense = bc->sense; - rq->sense_len = 0; - /* * add bc command to busy queue and submit rq for io */ @@ -419,7 +421,7 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr, { int ret = 0; - dprintk("rq %p bio %p %u\n", rq, bio, rq->errors); + dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors); /* * fill in all the output members */ @@ -635,7 +637,7 @@ static int __bsg_write(struct bsg_device *bd, const char __user *buf, /* * get a request, fill in the blanks, and add to request queue */ - rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm); + rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense); if (IS_ERR(rq)) { ret = PTR_ERR(rq); rq = NULL; @@ -922,11 +924,12 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct request *rq; struct bio *bio, *bidi_bio = NULL; struct sg_io_v4 hdr; + u8 sense[SCSI_SENSE_BUFFERSIZE]; if (copy_from_user(&hdr, uarg, sizeof(hdr))) return -EFAULT; - rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE); + rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense); if (IS_ERR(rq)) return PTR_ERR(rq); -- cgit v1.2.3 From 93dbb393503d53cd226e5e1f0088fe8f4dbaa2b8 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 16 Feb 2009 10:25:40 +0100 Subject: block: fix bad definition of BIO_RW_SYNC We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe --- block/blktrace.c | 2 +- drivers/md/dm-io.c | 2 +- drivers/md/dm-kcopyd.c | 2 +- drivers/md/md.c | 4 ++-- include/linux/bio.h | 2 -- include/linux/blktrace_api.h | 1 + include/linux/fs.h | 6 +++--- kernel/power/swap.c | 5 +++-- mm/page_io.c | 2 +- 9 files changed, 13 insertions(+), 13 deletions(-) (limited to 'block') diff --git a/block/blktrace.c b/block/blktrace.c index 39cc3bfe56e4..7cf9d1ff45a0 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -142,7 +142,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, what |= ddir_act[rw & WRITE]; what |= MASK_TC_BIT(rw, BARRIER); - what |= MASK_TC_BIT(rw, SYNC); + what |= MASK_TC_BIT(rw, SYNCIO); what |= MASK_TC_BIT(rw, AHEAD); what |= MASK_TC_BIT(rw, META); what |= MASK_TC_BIT(rw, DISCARD); diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index a34338567a2a..f14813be4eff 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -328,7 +328,7 @@ static void dispatch_io(int rw, unsigned int num_regions, struct dpages old_pages = *dp; if (sync) - rw |= (1 << BIO_RW_SYNC); + rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); /* * For multiple regions we need to be careful to rewind diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c index 3073618269ea..0a225da21272 100644 --- a/drivers/md/dm-kcopyd.c +++ b/drivers/md/dm-kcopyd.c @@ -344,7 +344,7 @@ static int run_io_job(struct kcopyd_job *job) { int r; struct dm_io_request io_req = { - .bi_rw = job->rw | (1 << BIO_RW_SYNC), + .bi_rw = job->rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG), .mem.type = DM_IO_PAGE_LIST, .mem.ptr.pl = job->pages, .mem.offset = job->offset, diff --git a/drivers/md/md.c b/drivers/md/md.c index 4495104f6c9f..03b4cd0a6344 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -474,7 +474,7 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev, * causes ENOTSUPP, we allocate a spare bio... */ struct bio *bio = bio_alloc(GFP_NOIO, 1); - int rw = (1<bi_bdev = rdev->bdev; bio->bi_sector = sector; @@ -531,7 +531,7 @@ int sync_page_io(struct block_device *bdev, sector_t sector, int size, struct completion event; int ret; - rw |= (1 << BIO_RW_SYNC); + rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); bio->bi_bdev = bdev; bio->bi_sector = sector; diff --git a/include/linux/bio.h b/include/linux/bio.h index 2aa283ab062b..1b16108a5417 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -171,8 +171,6 @@ struct bio { #define BIO_RW_FAILFAST_TRANSPORT 8 #define BIO_RW_FAILFAST_DRIVER 9 -#define BIO_RW_SYNC (BIO_RW_SYNCIO | BIO_RW_UNPLUG) - #define bio_rw_flagged(bio, flag) ((bio)->bi_rw & (1 << (flag))) /* diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index 25379cba2370..6e915878e88c 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -15,6 +15,7 @@ enum blktrace_cat { BLK_TC_WRITE = 1 << 1, /* writes */ BLK_TC_BARRIER = 1 << 2, /* barrier */ BLK_TC_SYNC = 1 << 3, /* sync IO */ + BLK_TC_SYNCIO = BLK_TC_SYNC, BLK_TC_QUEUE = 1 << 4, /* queueing/merging */ BLK_TC_REQUEUE = 1 << 5, /* requeueing */ BLK_TC_ISSUE = 1 << 6, /* issue */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 6022f44043f2..67857dc16365 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -87,10 +87,10 @@ struct inodes_stat_t { #define WRITE 1 #define READA 2 /* read-ahead - don't block if no resources */ #define SWRITE 3 /* for ll_rw_block() - wait for buffer lock */ -#define READ_SYNC (READ | (1 << BIO_RW_SYNC)) +#define READ_SYNC (READ | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG)) #define READ_META (READ | (1 << BIO_RW_META)) -#define WRITE_SYNC (WRITE | (1 << BIO_RW_SYNC)) -#define SWRITE_SYNC (SWRITE | (1 << BIO_RW_SYNC)) +#define WRITE_SYNC (WRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG)) +#define SWRITE_SYNC (SWRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG)) #define WRITE_BARRIER (WRITE | (1 << BIO_RW_BARRIER)) #define DISCARD_NOBARRIER (1 << BIO_RW_DISCARD) #define DISCARD_BARRIER ((1 << BIO_RW_DISCARD) | (1 << BIO_RW_BARRIER)) diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 6da14358537c..505f319e489c 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -60,6 +60,7 @@ static struct block_device *resume_bdev; static int submit(int rw, pgoff_t page_off, struct page *page, struct bio **bio_chain) { + const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); struct bio *bio; bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1); @@ -80,7 +81,7 @@ static int submit(int rw, pgoff_t page_off, struct page *page, bio_get(bio); if (bio_chain == NULL) { - submit_bio(rw | (1 << BIO_RW_SYNC), bio); + submit_bio(bio_rw, bio); wait_on_page_locked(page); if (rw == READ) bio_set_pages_dirty(bio); @@ -90,7 +91,7 @@ static int submit(int rw, pgoff_t page_off, struct page *page, get_page(page); /* These pages are freed later */ bio->bi_private = *bio_chain; *bio_chain = bio; - submit_bio(rw | (1 << BIO_RW_SYNC), bio); + submit_bio(bio_rw, bio); } return 0; } diff --git a/mm/page_io.c b/mm/page_io.c index dc6ce0afbded..3023c475e041 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -111,7 +111,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc) goto out; } if (wbc->sync_mode == WB_SYNC_ALL) - rw |= (1 << BIO_RW_SYNC); + rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); count_vm_event(PSWPOUT); set_page_writeback(page); unlock_page(page); -- cgit v1.2.3 From 41b8c853a495438208faa5be03bbb0050859163b Mon Sep 17 00:00:00 2001 From: Neil Brown Date: Wed, 18 Feb 2009 10:33:59 +0100 Subject: block: fix booting from partitioned md array Hi Tejun, it looks like your commit: block: don't depend on consecutive minor space f331c0296f2a9fee0d396a70598b954062603015 broke a particular case for booting from partitioned md/raid devices. That is the second time this has been broken recently. The previous time was fixed by block: do_mounts - accept root= 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Because the data isn't available when an md device is first created (we add disks and set it up after creation), the initial partition scan finds nothing. It is not until the device is opened that another partition scan happens and finds something. So at the point where the kernel parameter "root=/dev/md_d0p1" is being parsed, md_d0 exists, but md_d0p1 does not. However if we let blk_lookup_devt return the correct device number even though the device doesn't exist, then the attempt to mount it will successfully find the partition. I have tried in the past to find a way to get the partition table to be read as soon as the array is assembled but that proved impossible (at the time). I don't remember the details, and could possibly revisit it. However it would be really nice if blk_lookup_devt could be adjusted to again accept non existant partitions. Signed-off-by: Jens Axboe --- block/genhd.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'block') diff --git a/block/genhd.c b/block/genhd.c index 397960cf26af..e1eadcc9546a 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1087,6 +1087,14 @@ dev_t blk_lookup_devt(const char *name, int partno) if (strcmp(dev_name(dev), name)) continue; + if (partno < disk->minors) { + /* We need to return the right devno, even + * if the partition doesn't exist yet. + */ + devt = MKDEV(MAJOR(dev->devt), + MINOR(dev->devt) + partno); + break; + } part = disk_get_part(disk, partno); if (part) { devt = part_devt(part); -- cgit v1.2.3 From be987fdb55a4726e2fcbab7501f89276bdb57288 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Wed, 18 Feb 2009 10:30:15 +0100 Subject: block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list blk_abort_queue() iterates the timeout list and aborts each request on the list, but if the driver error handling readds a request to the timeout list during this processing, we could be looping forever. Fix this by splicing current entries to a local list and run over that list instead. Signed-off-by: Jens Axboe --- block/blk-timeout.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/blk-timeout.c b/block/blk-timeout.c index a09535377a94..bbbdc4b8ccf2 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -209,12 +209,19 @@ void blk_abort_queue(struct request_queue *q) { unsigned long flags; struct request *rq, *tmp; + LIST_HEAD(list); spin_lock_irqsave(q->queue_lock, flags); elv_abort_queue(q); - list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list) + /* + * Splice entries to local list, to avoid deadlocking if entries + * get readded to the timeout list by error handling + */ + list_splice_init(&q->timeout_list, &list); + + list_for_each_entry_safe(rq, tmp, &list, timeout_list) blk_abort_request(rq); spin_unlock_irqrestore(q->queue_lock, flags); -- cgit v1.2.3 From 313e458f81ec3852106c5a83830fe0d4f405a71a Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 20 Feb 2009 16:29:08 +0900 Subject: alloc_percpu: add align argument to __alloc_percpu. This prepares for a real __alloc_percpu, by adding an alignment argument. Only one place uses __alloc_percpu directly, and that's for a string. tj: af_inet also uses __alloc_percpu(), update it. Signed-off-by: Rusty Russell Cc: Christoph Lameter Cc: Jens Axboe --- block/blktrace.c | 2 +- include/linux/percpu.h | 5 +++-- net/ipv4/af_inet.c | 4 ++-- 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'block') diff --git a/block/blktrace.c b/block/blktrace.c index 39cc3bfe56e4..487766237d28 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -363,7 +363,7 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, if (!bt->sequence) goto err; - bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG); + bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char)); if (!bt->msg_data) goto err; diff --git a/include/linux/percpu.h b/include/linux/percpu.h index c80cfe1260ec..1fdaee93c04d 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -108,9 +108,10 @@ static inline void percpu_free(void *__pdata) /* (legacy) interface for use without CPU hotplug handling */ -#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \ +#define __alloc_percpu(size, align) percpu_alloc_mask((size), GFP_KERNEL, \ cpu_possible_map) -#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type)) +#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ + __alignof__(type)) #define free_percpu(ptr) percpu_free((ptr)) /* * Use this to get to a cpu's version of the per-cpu object dynamically diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 743f5542d65a..3a3dad801354 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1375,10 +1375,10 @@ EXPORT_SYMBOL_GPL(snmp_fold_field); int snmp_mib_init(void *ptr[2], size_t mibsize) { BUG_ON(ptr == NULL); - ptr[0] = __alloc_percpu(mibsize); + ptr[0] = __alloc_percpu(mibsize, __alignof__(unsigned long long)); if (!ptr[0]) goto err0; - ptr[1] = __alloc_percpu(mibsize); + ptr[1] = __alloc_percpu(mibsize, __alignof__(unsigned long long)); if (!ptr[1]) goto err1; return 0; -- cgit v1.2.3 From 9e8c0bccdc944bd09361672d47660810c027bcaa Mon Sep 17 00:00:00 2001 From: Márton Németh Date: Fri, 20 Feb 2009 08:12:51 +0100 Subject: block: add documentation for register_blkdev() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add documentation for register_blkdev() function and for the parameters. Signed-off-by: Márton Németh Cc: Greg Kroah-Hartman Signed-off-by: Jens Axboe --- block/genhd.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'block') diff --git a/block/genhd.c b/block/genhd.c index e1eadcc9546a..a9ec910974c1 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -256,6 +256,22 @@ void blkdev_show(struct seq_file *seqf, off_t offset) } #endif /* CONFIG_PROC_FS */ +/** + * register_blkdev - register a new block device + * + * @major: the requested major device number [1..255]. If @major=0, try to + * allocate any unused major number. + * @name: the name of the new block device as a zero terminated string + * + * The @name must be unique within the system. + * + * The return value depends on the @major input parameter. + * - if a major device number was requested in range [1..255] then the + * function returns zero on success, or a negative error code + * - if any unused major number was requested with @major=0 parameter + * then the return value is the allocated major number in range + * [1..255] or a negative error code otherwise + */ int register_blkdev(unsigned int major, const char *name) { struct blk_major_name **n, *p; -- cgit v1.2.3 From 1e42807918d17e8c93bf14fbb74be84b141334c1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 23 Feb 2009 09:03:10 +0100 Subject: block: reduce stack footprint of blk_recount_segments() blk_recalc_rq_segments() requires a request structure passed in, which we don't have from blk_recount_segments(). So the latter allocates one on the stack, using > 400 bytes of stack for that. This can cause us to spill over one page of stack from ext4 at least: 0) 4560 400 blk_recount_segments+0x43/0x62 1) 4160 32 bio_phys_segments+0x1c/0x24 2) 4128 32 blk_rq_bio_prep+0x2a/0xf9 3) 4096 32 init_request_from_bio+0xf9/0xfe 4) 4064 112 __make_request+0x33c/0x3f6 5) 3952 144 generic_make_request+0x2d1/0x321 6) 3808 64 submit_bio+0xb9/0xc3 7) 3744 48 submit_bh+0xea/0x10e 8) 3696 368 ext4_mb_init_cache+0x257/0xa6a [ext4] 9) 3328 288 ext4_mb_regular_allocator+0x421/0xcd9 [ext4] 10) 3040 160 ext4_mb_new_blocks+0x211/0x4b4 [ext4] 11) 2880 336 ext4_ext_get_blocks+0xb61/0xd45 [ext4] 12) 2544 96 ext4_get_blocks_wrap+0xf2/0x200 [ext4] 13) 2448 80 ext4_da_get_block_write+0x6e/0x16b [ext4] 14) 2368 352 mpage_da_map_blocks+0x7e/0x4b3 [ext4] 15) 2016 352 ext4_da_writepages+0x2ce/0x43c [ext4] 16) 1664 32 do_writepages+0x2d/0x3c 17) 1632 144 __writeback_single_inode+0x162/0x2cd 18) 1488 96 generic_sync_sb_inodes+0x1e3/0x32b 19) 1392 16 sync_sb_inodes+0xe/0x10 20) 1376 48 writeback_inodes+0x69/0xb3 21) 1328 208 balance_dirty_pages_ratelimited_nr+0x187/0x2f9 22) 1120 224 generic_file_buffered_write+0x1d4/0x2c4 23) 896 176 __generic_file_aio_write_nolock+0x35f/0x393 24) 720 80 generic_file_aio_write+0x6c/0xc8 25) 640 80 ext4_file_write+0xa9/0x137 [ext4] 26) 560 320 do_sync_write+0xf0/0x137 27) 240 48 vfs_write+0xb3/0x13c 28) 192 64 sys_write+0x4c/0x74 29) 128 128 system_call_fastpath+0x16/0x1b Split the segment counting out into a __blk_recalc_rq_segments() helper to avoid allocating an onstack request just for checking the physical segment count. Signed-off-by: Jens Axboe --- block/blk-merge.c | 94 ++++++++++++++++++++++++++++---------------------- include/linux/blkdev.h | 2 ++ 2 files changed, 55 insertions(+), 41 deletions(-) (limited to 'block') diff --git a/block/blk-merge.c b/block/blk-merge.c index b92f5b0866b0..a104593e70c3 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -38,72 +38,84 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect) } } -void blk_recalc_rq_segments(struct request *rq) +static unsigned int __blk_recalc_rq_segments(struct request_queue *q, + struct bio *bio, + unsigned int *seg_size_ptr) { - int nr_phys_segs; unsigned int phys_size; struct bio_vec *bv, *bvprv = NULL; - int seg_size; - int cluster; - struct req_iterator iter; - int high, highprv = 1; - struct request_queue *q = rq->q; + int cluster, i, high, highprv = 1; + unsigned int seg_size, nr_phys_segs; + struct bio *fbio; - if (!rq->bio) - return; + if (!bio) + return 0; + fbio = bio; cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); seg_size = 0; phys_size = nr_phys_segs = 0; - rq_for_each_segment(bv, rq, iter) { - /* - * the trick here is making sure that a high page is never - * considered part of another segment, since that might - * change with the bounce page. - */ - high = page_to_pfn(bv->bv_page) > q->bounce_pfn; - if (high || highprv) - goto new_segment; - if (cluster) { - if (seg_size + bv->bv_len > q->max_segment_size) - goto new_segment; - if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv)) - goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv)) + for_each_bio(bio) { + bio_for_each_segment(bv, bio, i) { + /* + * the trick here is making sure that a high page is + * never considered part of another segment, since that + * might change with the bounce page. + */ + high = page_to_pfn(bv->bv_page) > q->bounce_pfn; + if (high || highprv) goto new_segment; + if (cluster) { + if (seg_size + bv->bv_len > q->max_segment_size) + goto new_segment; + if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv)) + goto new_segment; + if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv)) + goto new_segment; + + seg_size += bv->bv_len; + bvprv = bv; + continue; + } +new_segment: + if (nr_phys_segs == 1 && seg_size > + fbio->bi_seg_front_size) + fbio->bi_seg_front_size = seg_size; - seg_size += bv->bv_len; + nr_phys_segs++; bvprv = bv; - continue; + seg_size = bv->bv_len; + highprv = high; } -new_segment: - if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) - rq->bio->bi_seg_front_size = seg_size; - - nr_phys_segs++; - bvprv = bv; - seg_size = bv->bv_len; - highprv = high; } - if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) + if (seg_size_ptr) + *seg_size_ptr = seg_size; + + return nr_phys_segs; +} + +void blk_recalc_rq_segments(struct request *rq) +{ + unsigned int seg_size = 0, phys_segs; + + phys_segs = __blk_recalc_rq_segments(rq->q, rq->bio, &seg_size); + + if (phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) rq->bio->bi_seg_front_size = seg_size; if (seg_size > rq->biotail->bi_seg_back_size) rq->biotail->bi_seg_back_size = seg_size; - rq->nr_phys_segments = nr_phys_segs; + rq->nr_phys_segments = phys_segs; } void blk_recount_segments(struct request_queue *q, struct bio *bio) { - struct request rq; struct bio *nxt = bio->bi_next; - rq.q = q; - rq.bio = rq.biotail = bio; + bio->bi_next = NULL; - blk_recalc_rq_segments(&rq); + bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, NULL); bio->bi_next = nxt; - bio->bi_phys_segments = rq.nr_phys_segments; bio->bi_flags |= (1 << BIO_SEG_VALID); } EXPORT_SYMBOL(blk_recount_segments); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index dcaa0fd84b02..465d6babc847 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -708,6 +708,8 @@ struct req_iterator { }; /* This should not be used directly - use rq_for_each_segment */ +#define for_each_bio(_bio) \ + for (; _bio; _bio = _bio->bi_next) #define __rq_for_each_bio(_bio, rq) \ if ((rq->bio)) \ for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) -- cgit v1.2.3 From 59247eaea50cc68cc6ce3d3fd3855f3301b65c96 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 6 Mar 2009 08:55:24 +0100 Subject: block: fix missing bio back/front segment size setting in blk_recount_segments() Commit 1e42807918d17e8c93bf14fbb74be84b141334c1 introduced a bug where we don't get front/back segment sizes in the bio in blk_recount_segments(). Fix this by tracking the back bio as well as the front bio in __blk_recalc_rq_segments(), this also cleans up the interface by getting rid of the segment size pointer passing. Tested-by: Thomas Gleixner Tested-by: Ingo Molnar Signed-off-by: Jens Axboe --- block/blk-merge.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'block') diff --git a/block/blk-merge.c b/block/blk-merge.c index a104593e70c3..5a244f05360f 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -39,14 +39,13 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect) } static unsigned int __blk_recalc_rq_segments(struct request_queue *q, - struct bio *bio, - unsigned int *seg_size_ptr) + struct bio *bio) { unsigned int phys_size; struct bio_vec *bv, *bvprv = NULL; int cluster, i, high, highprv = 1; unsigned int seg_size, nr_phys_segs; - struct bio *fbio; + struct bio *fbio, *bbio; if (!bio) return 0; @@ -87,26 +86,20 @@ new_segment: seg_size = bv->bv_len; highprv = high; } + bbio = bio; } - if (seg_size_ptr) - *seg_size_ptr = seg_size; + if (nr_phys_segs == 1 && seg_size > fbio->bi_seg_front_size) + fbio->bi_seg_front_size = seg_size; + if (seg_size > bbio->bi_seg_back_size) + bbio->bi_seg_back_size = seg_size; return nr_phys_segs; } void blk_recalc_rq_segments(struct request *rq) { - unsigned int seg_size = 0, phys_segs; - - phys_segs = __blk_recalc_rq_segments(rq->q, rq->bio, &seg_size); - - if (phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size) - rq->bio->bi_seg_front_size = seg_size; - if (seg_size > rq->biotail->bi_seg_back_size) - rq->biotail->bi_seg_back_size = seg_size; - - rq->nr_phys_segments = phys_segs; + rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio); } void blk_recount_segments(struct request_queue *q, struct bio *bio) @@ -114,7 +107,7 @@ void blk_recount_segments(struct request_queue *q, struct bio *bio) struct bio *nxt = bio->bi_next; bio->bi_next = NULL; - bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, NULL); + bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio); bio->bi_next = nxt; bio->bi_flags |= (1 << BIO_SEG_VALID); } -- cgit v1.2.3