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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 14:29:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 14:29:53 -0700
commitbfffa1cc9db8a950dd4b1a09999f8a20e69a6652 (patch)
tree01b046072ca9105b7852f790762f7b00b72e6ff7 /block
parentcc8a0a943948d1b1bc803b37486831af7b04dd38 (diff)
parentae994ea972473c0ace9d55f718b60f0727af1381 (diff)
downloadlwn-bfffa1cc9db8a950dd4b1a09999f8a20e69a6652.tar.gz
lwn-bfffa1cc9db8a950dd4b1a09999f8a20e69a6652.zip
Merge branch 'for-4.2/core' of git://git.kernel.dk/linux-block
Pull core block IO update from Jens Axboe: "Nothing really major in here, mostly a collection of smaller optimizations and cleanups, mixed with various fixes. In more detail, this contains: - Addition of policy specific data to blkcg for block cgroups. From Arianna Avanzini. - Various cleanups around command types from Christoph. - Cleanup of the suspend block I/O path from Christoph. - Plugging updates from Shaohua and Jeff Moyer, for blk-mq. - Eliminating atomic inc/dec of both remaining IO count and reference count in a bio. From me. - Fixes for SG gap and chunk size support for data-less (discards) IO, so we can merge these better. From me. - Small restructuring of blk-mq shared tag support, freeing drivers from iterating hardware queues. From Keith Busch. - A few cfq-iosched tweaks, from Tahsin Erdogan and me. Makes the IOPS mode the default for non-rotational storage" * 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits) cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL cfq-iosched: fix sysfs oops when attempting to read unconfigured weights cfq-iosched: move group scheduling functions under ifdef cfq-iosched: fix the setting of IOPS mode on SSDs blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file block, cgroup: implement policy-specific per-blkcg data block: Make CFQ default to IOPS mode on SSDs block: add blk_set_queue_dying() to blkdev.h blk-mq: Shared tag enhancements block: don't honor chunk sizes for data-less IO block: only honor SG gap prevention for merges that contain data block: fix returnvar.cocci warnings block, dm: don't copy bios for request clones block: remove management of bi_remaining when restoring original bi_end_io block: replace trylock with mutex_lock in blkdev_reread_part() block: export blkdev_reread_part() and __blkdev_reread_part() suspend: simplify block I/O handling block: collapse bio bit space block: remove unused BIO_RW_BLOCK and BIO_EOF flags block: remove BIO_EOPNOTSUPP ...
Diffstat (limited to 'block')
-rw-r--r--block/bio-integrity.c4
-rw-r--r--block/bio.c77
-rw-r--r--block/blk-cgroup.c92
-rw-r--r--block/blk-cgroup.h40
-rw-r--r--block/blk-core.c136
-rw-r--r--block/blk-exec.c10
-rw-r--r--block/blk-merge.c3
-rw-r--r--block/blk-mq-tag.c38
-rw-r--r--block/blk-mq-tag.h1
-rw-r--r--block/blk-mq.c160
-rw-r--r--block/blk.h5
-rw-r--r--block/bounce.c3
-rw-r--r--block/cfq-iosched.c125
-rw-r--r--block/elevator.c2
-rw-r--r--block/ioctl.c37
15 files changed, 478 insertions, 255 deletions
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 5cbd5d9ea61d..0436c21db7f2 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -361,7 +361,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
/* Restore original bio completion handler */
bio->bi_end_io = bip->bip_end_io;
- bio_endio_nodec(bio, error);
+ bio_endio(bio, error);
}
/**
@@ -388,7 +388,7 @@ void bio_integrity_endio(struct bio *bio, int error)
*/
if (error) {
bio->bi_end_io = bip->bip_end_io;
- bio_endio_nodec(bio, error);
+ bio_endio(bio, error);
return;
}
diff --git a/block/bio.c b/block/bio.c
index f66a4eae16ee..259197d97de1 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -270,8 +270,8 @@ void bio_init(struct bio *bio)
{
memset(bio, 0, sizeof(*bio));
bio->bi_flags = 1 << BIO_UPTODATE;
- atomic_set(&bio->bi_remaining, 1);
- atomic_set(&bio->bi_cnt, 1);
+ atomic_set(&bio->__bi_remaining, 1);
+ atomic_set(&bio->__bi_cnt, 1);
}
EXPORT_SYMBOL(bio_init);
@@ -292,8 +292,8 @@ void bio_reset(struct bio *bio)
__bio_free(bio);
memset(bio, 0, BIO_RESET_BYTES);
- bio->bi_flags = flags|(1 << BIO_UPTODATE);
- atomic_set(&bio->bi_remaining, 1);
+ bio->bi_flags = flags | (1 << BIO_UPTODATE);
+ atomic_set(&bio->__bi_remaining, 1);
}
EXPORT_SYMBOL(bio_reset);
@@ -303,6 +303,17 @@ static void bio_chain_endio(struct bio *bio, int error)
bio_put(bio);
}
+/*
+ * Increment chain count for the bio. Make sure the CHAIN flag update
+ * is visible before the raised count.
+ */
+static inline void bio_inc_remaining(struct bio *bio)
+{
+ bio->bi_flags |= (1 << BIO_CHAIN);
+ smp_mb__before_atomic();
+ atomic_inc(&bio->__bi_remaining);
+}
+
/**
* bio_chain - chain bio completions
* @bio: the target bio
@@ -320,7 +331,7 @@ void bio_chain(struct bio *bio, struct bio *parent)
bio->bi_private = parent;
bio->bi_end_io = bio_chain_endio;
- atomic_inc(&parent->bi_remaining);
+ bio_inc_remaining(parent);
}
EXPORT_SYMBOL(bio_chain);
@@ -524,13 +535,17 @@ EXPORT_SYMBOL(zero_fill_bio);
**/
void bio_put(struct bio *bio)
{
- BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
-
- /*
- * last put frees it
- */
- if (atomic_dec_and_test(&bio->bi_cnt))
+ if (!bio_flagged(bio, BIO_REFFED))
bio_free(bio);
+ else {
+ BIO_BUG_ON(!atomic_read(&bio->__bi_cnt));
+
+ /*
+ * last put frees it
+ */
+ if (atomic_dec_and_test(&bio->__bi_cnt))
+ bio_free(bio);
+ }
}
EXPORT_SYMBOL(bio_put);
@@ -1741,6 +1756,25 @@ void bio_flush_dcache_pages(struct bio *bi)
EXPORT_SYMBOL(bio_flush_dcache_pages);
#endif
+static inline bool bio_remaining_done(struct bio *bio)
+{
+ /*
+ * If we're not chaining, then ->__bi_remaining is always 1 and
+ * we always end io on the first invocation.
+ */
+ if (!bio_flagged(bio, BIO_CHAIN))
+ return true;
+
+ BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
+
+ if (atomic_dec_and_test(&bio->__bi_remaining)) {
+ clear_bit(BIO_CHAIN, &bio->bi_flags);
+ return true;
+ }
+
+ return false;
+}
+
/**
* bio_endio - end I/O on a bio
* @bio: bio
@@ -1758,15 +1792,13 @@ EXPORT_SYMBOL(bio_flush_dcache_pages);
void bio_endio(struct bio *bio, int error)
{
while (bio) {
- BUG_ON(atomic_read(&bio->bi_remaining) <= 0);
-
if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
error = -EIO;
- if (!atomic_dec_and_test(&bio->bi_remaining))
- return;
+ if (unlikely(!bio_remaining_done(bio)))
+ break;
/*
* Need to have a real endio function for chained bios,
@@ -1790,21 +1822,6 @@ void bio_endio(struct bio *bio, int error)
EXPORT_SYMBOL(bio_endio);
/**
- * bio_endio_nodec - end I/O on a bio, without decrementing bi_remaining
- * @bio: bio
- * @error: error, if any
- *
- * For code that has saved and restored bi_end_io; thing hard before using this
- * function, probably you should've cloned the entire bio.
- **/
-void bio_endio_nodec(struct bio *bio, int error)
-{
- atomic_inc(&bio->bi_remaining);
- bio_endio(bio, error);
-}
-EXPORT_SYMBOL(bio_endio_nodec);
-
-/**
* bio_split - split a bio
* @bio: bio to split
* @sectors: number of sectors to split from the front of @bio
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0ac817b750db..6e43fa355e71 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -9,6 +9,10 @@
*
* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
* Nauman Rafique <nauman@google.com>
+ *
+ * For policy-specific per-blkcg data:
+ * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
+ * Arianna Avanzini <avanzini.arianna@gmail.com>
*/
#include <linux/ioprio.h>
#include <linux/kdev_t.h>
@@ -26,8 +30,7 @@
static DEFINE_MUTEX(blkcg_pol_mutex);
-struct blkcg blkcg_root = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT,
- .cfq_leaf_weight = 2 * CFQ_WEIGHT_DEFAULT, };
+struct blkcg blkcg_root;
EXPORT_SYMBOL_GPL(blkcg_root);
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
@@ -823,6 +826,8 @@ static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct blkcg *blkcg;
+ struct cgroup_subsys_state *ret;
+ int i;
if (!parent_css) {
blkcg = &blkcg_root;
@@ -830,17 +835,49 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
}
blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg)
- return ERR_PTR(-ENOMEM);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
+
+ for (i = 0; i < BLKCG_MAX_POLS ; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg_policy_data *cpd;
+
+ /*
+ * If the policy hasn't been attached yet, wait for it
+ * to be attached before doing anything else. Otherwise,
+ * check if the policy requires any specific per-cgroup
+ * data: if it does, allocate and initialize it.
+ */
+ if (!pol || !pol->cpd_size)
+ continue;
+
+ BUG_ON(blkcg->pd[i]);
+ cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
+ if (!cpd) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_pd_blkcg;
+ }
+ blkcg->pd[i] = cpd;
+ cpd->plid = i;
+ pol->cpd_init_fn(blkcg);
+ }
- blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
- blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
done:
spin_lock_init(&blkcg->lock);
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
INIT_HLIST_HEAD(&blkcg->blkg_list);
return &blkcg->css;
+
+free_pd_blkcg:
+ for (i--; i >= 0; i--)
+ kfree(blkcg->pd[i]);
+
+free_blkcg:
+ kfree(blkcg);
+ return ret;
}
/**
@@ -958,8 +995,10 @@ int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
LIST_HEAD(pds);
+ LIST_HEAD(cpds);
struct blkcg_gq *blkg, *new_blkg;
- struct blkg_policy_data *pd, *n;
+ struct blkg_policy_data *pd, *nd;
+ struct blkcg_policy_data *cpd, *cnd;
int cnt = 0, ret;
bool preloaded;
@@ -1003,7 +1042,10 @@ int blkcg_activate_policy(struct request_queue *q,
spin_unlock_irq(q->queue_lock);
- /* allocate policy_data for all existing blkgs */
+ /*
+ * Allocate per-blkg and per-blkcg policy data
+ * for all existing blkgs.
+ */
while (cnt--) {
pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
if (!pd) {
@@ -1011,26 +1053,50 @@ int blkcg_activate_policy(struct request_queue *q,
goto out_free;
}
list_add_tail(&pd->alloc_node, &pds);
+
+ if (!pol->cpd_size)
+ continue;
+ cpd = kzalloc_node(pol->cpd_size, GFP_KERNEL, q->node);
+ if (!cpd) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ list_add_tail(&cpd->alloc_node, &cpds);
}
/*
- * Install the allocated pds. With @q bypassing, no new blkg
+ * Install the allocated pds and cpds. With @q bypassing, no new blkg
* should have been created while the queue lock was dropped.
*/
spin_lock_irq(q->queue_lock);
list_for_each_entry(blkg, &q->blkg_list, q_node) {
- if (WARN_ON(list_empty(&pds))) {
+ if (WARN_ON(list_empty(&pds)) ||
+ WARN_ON(pol->cpd_size && list_empty(&cpds))) {
/* umm... this shouldn't happen, just abort */
ret = -ENOMEM;
goto out_unlock;
}
+ cpd = list_first_entry(&cpds, struct blkcg_policy_data,
+ alloc_node);
+ list_del_init(&cpd->alloc_node);
pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node);
list_del_init(&pd->alloc_node);
/* grab blkcg lock too while installing @pd on @blkg */
spin_lock(&blkg->blkcg->lock);
+ if (!pol->cpd_size)
+ goto no_cpd;
+ if (!blkg->blkcg->pd[pol->plid]) {
+ /* Per-policy per-blkcg data */
+ blkg->blkcg->pd[pol->plid] = cpd;
+ cpd->plid = pol->plid;
+ pol->cpd_init_fn(blkg->blkcg);
+ } else { /* must free it as it has already been extracted */
+ kfree(cpd);
+ }
+no_cpd:
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
@@ -1045,8 +1111,10 @@ out_unlock:
spin_unlock_irq(q->queue_lock);
out_free:
blk_queue_bypass_end(q);
- list_for_each_entry_safe(pd, n, &pds, alloc_node)
+ list_for_each_entry_safe(pd, nd, &pds, alloc_node)
kfree(pd);
+ list_for_each_entry_safe(cpd, cnd, &cpds, alloc_node)
+ kfree(cpd);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
@@ -1087,6 +1155,8 @@ void blkcg_deactivate_policy(struct request_queue *q,
kfree(blkg->pd[pol->plid]);
blkg->pd[pol->plid] = NULL;
+ kfree(blkg->blkcg->pd[pol->plid]);
+ blkg->blkcg->pd[pol->plid] = NULL;
spin_unlock(&blkg->blkcg->lock);
}
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index c567865b5f1d..74296a78bba1 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -23,11 +23,6 @@
/* Max limits for throttle policy */
#define THROTL_IOPS_MAX UINT_MAX
-/* CFQ specific, out here for blkcg->cfq_weight */
-#define CFQ_WEIGHT_MIN 10
-#define CFQ_WEIGHT_MAX 1000
-#define CFQ_WEIGHT_DEFAULT 500
-
#ifdef CONFIG_BLK_CGROUP
enum blkg_rwstat_type {
@@ -50,9 +45,7 @@ struct blkcg {
struct blkcg_gq *blkg_hint;
struct hlist_head blkg_list;
- /* TODO: per-policy storage in blkcg */
- unsigned int cfq_weight; /* belongs to cfq */
- unsigned int cfq_leaf_weight;
+ struct blkcg_policy_data *pd[BLKCG_MAX_POLS];
};
struct blkg_stat {
@@ -87,6 +80,24 @@ struct blkg_policy_data {
struct list_head alloc_node;
};
+/*
+ * Policies that need to keep per-blkcg data which is independent
+ * from any request_queue associated to it must specify its size
+ * with the cpd_size field of the blkcg_policy structure and
+ * embed a blkcg_policy_data in it. blkcg core allocates
+ * policy-specific per-blkcg structures lazily the first time
+ * they are actually needed, so it handles them together with
+ * blkgs. cpd_init() is invoked to let each policy handle
+ * per-blkcg data.
+ */
+struct blkcg_policy_data {
+ /* the policy id this per-policy data belongs to */
+ int plid;
+
+ /* used during policy activation */
+ struct list_head alloc_node;
+};
+
/* association between a blk cgroup and a request queue */
struct blkcg_gq {
/* Pointer to the associated request_queue */
@@ -112,6 +123,7 @@ struct blkcg_gq {
struct rcu_head rcu_head;
};
+typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
@@ -122,10 +134,13 @@ struct blkcg_policy {
int plid;
/* policy specific private data size */
size_t pd_size;
+ /* policy specific per-blkcg data size */
+ size_t cpd_size;
/* cgroup files for the policy */
struct cftype *cftypes;
/* operations */
+ blkcg_pol_init_cpd_fn *cpd_init_fn;
blkcg_pol_init_pd_fn *pd_init_fn;
blkcg_pol_online_pd_fn *pd_online_fn;
blkcg_pol_offline_pd_fn *pd_offline_fn;
@@ -218,6 +233,12 @@ static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
return blkg ? blkg->pd[pol->plid] : NULL;
}
+static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
+ struct blkcg_policy *pol)
+{
+ return blkcg ? blkcg->pd[pol->plid] : NULL;
+}
+
/**
* pdata_to_blkg - get blkg associated with policy private data
* @pd: policy private data of interest
@@ -564,6 +585,9 @@ struct blkcg;
struct blkg_policy_data {
};
+struct blkcg_policy_data {
+};
+
struct blkcg_gq {
};
diff --git a/block/blk-core.c b/block/blk-core.c
index 03b5f8d77f37..f6ab750060fe 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -117,7 +117,7 @@ EXPORT_SYMBOL(blk_rq_init);
static void req_bio_endio(struct request *rq, struct bio *bio,
unsigned int nbytes, int error)
{
- if (error)
+ if (error && !(rq->cmd_flags & REQ_CLONE))
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
error = -EIO;
@@ -128,7 +128,8 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
bio_advance(bio, nbytes);
/* don't actually finish bio if it's part of flush sequence */
- if (bio->bi_iter.bi_size == 0 && !(rq->cmd_flags & REQ_FLUSH_SEQ))
+ if (bio->bi_iter.bi_size == 0 &&
+ !(rq->cmd_flags & (REQ_FLUSH_SEQ|REQ_CLONE)))
bio_endio(bio, error);
}
@@ -285,6 +286,7 @@ inline void __blk_run_queue_uncond(struct request_queue *q)
q->request_fn(q);
q->request_fn_active--;
}
+EXPORT_SYMBOL_GPL(__blk_run_queue_uncond);
/**
* __blk_run_queue - run a single device queue
@@ -1525,7 +1527,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- unsigned int *request_count)
+ unsigned int *request_count,
+ struct request **same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
@@ -1545,8 +1548,16 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
list_for_each_entry_reverse(rq, plug_list, queuelist) {
int el_ret;
- if (rq->q == q)
+ if (rq->q == q) {
(*request_count)++;
+ /*
+ * Only blk-mq multiple hardware queues case checks the
+ * rq in the same queue, there should be only one such
+ * rq in a queue
+ **/
+ if (same_queue_rq)
+ *same_queue_rq = rq;
+ }
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
@@ -1611,7 +1622,7 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio)
* any locks.
*/
if (!blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count))
+ blk_attempt_plug_merge(q, bio, &request_count, NULL))
return;
spin_lock_irq(q->queue_lock);
@@ -1718,8 +1729,6 @@ static void handle_bad_sector(struct bio *bio)
bio->bi_rw,
(unsigned long long)bio_end_sector(bio),
(long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9));
-
- set_bit(BIO_EOF, &bio->bi_flags);
}
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -2904,95 +2913,22 @@ int blk_lld_busy(struct request_queue *q)
}
EXPORT_SYMBOL_GPL(blk_lld_busy);
-/**
- * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
- * @rq: the clone request to be cleaned up
- *
- * Description:
- * Free all bios in @rq for a cloned request.
- */
-void blk_rq_unprep_clone(struct request *rq)
-{
- struct bio *bio;
-
- while ((bio = rq->bio) != NULL) {
- rq->bio = bio->bi_next;
-
- bio_put(bio);
- }
-}
-EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
-
-/*
- * Copy attributes of the original request to the clone request.
- * The actual data parts (e.g. ->cmd, ->sense) are not copied.
- */
-static void __blk_rq_prep_clone(struct request *dst, struct request *src)
+void blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags |= (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
+ dst->cmd_flags |= (src->cmd_flags & REQ_CLONE_MASK);
+ dst->cmd_flags |= REQ_NOMERGE | REQ_CLONE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
dst->nr_phys_segments = src->nr_phys_segments;
dst->ioprio = src->ioprio;
dst->extra_len = src->extra_len;
-}
-
-/**
- * blk_rq_prep_clone - Helper function to setup clone request
- * @rq: the request to be setup
- * @rq_src: original request to be cloned
- * @bs: bio_set that bios for clone are allocated from
- * @gfp_mask: memory allocation mask for bio
- * @bio_ctr: setup function to be called for each clone bio.
- * Returns %0 for success, non %0 for failure.
- * @data: private data to be passed to @bio_ctr
- *
- * Description:
- * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
- * The actual data parts of @rq_src (e.g. ->cmd, ->sense)
- * are not copied, and copying such parts is the caller's responsibility.
- * Also, pages which the original bios are pointing to are not copied
- * and the cloned bios just point same pages.
- * So cloned bios must be completed before original bios, which means
- * the caller must complete @rq before @rq_src.
- */
-int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
- struct bio_set *bs, gfp_t gfp_mask,
- int (*bio_ctr)(struct bio *, struct bio *, void *),
- void *data)
-{
- struct bio *bio, *bio_src;
-
- if (!bs)
- bs = fs_bio_set;
-
- __rq_for_each_bio(bio_src, rq_src) {
- bio = bio_clone_fast(bio_src, gfp_mask, bs);
- if (!bio)
- goto free_and_out;
-
- if (bio_ctr && bio_ctr(bio, bio_src, data))
- goto free_and_out;
-
- if (rq->bio) {
- rq->biotail->bi_next = bio;
- rq->biotail = bio;
- } else
- rq->bio = rq->biotail = bio;
- }
-
- __blk_rq_prep_clone(rq, rq_src);
-
- return 0;
-
-free_and_out:
- if (bio)
- bio_put(bio);
- blk_rq_unprep_clone(rq);
-
- return -ENOMEM;
+ dst->bio = src->bio;
+ dst->biotail = src->biotail;
+ dst->cmd = src->cmd;
+ dst->cmd_len = src->cmd_len;
+ dst->sense = src->sense;
}
EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
@@ -3034,21 +2970,20 @@ void blk_start_plug(struct blk_plug *plug)
{
struct task_struct *tsk = current;
+ /*
+ * If this is a nested plug, don't actually assign it.
+ */
+ if (tsk->plug)
+ return;
+
INIT_LIST_HEAD(&plug->list);
INIT_LIST_HEAD(&plug->mq_list);
INIT_LIST_HEAD(&plug->cb_list);
-
/*
- * If this is a nested plug, don't actually assign it. It will be
- * flushed on its own.
+ * Store ordering should not be needed here, since a potential
+ * preempt will imply a full memory barrier
*/
- if (!tsk->plug) {
- /*
- * Store ordering should not be needed here, since a potential
- * preempt will imply a full memory barrier
- */
- tsk->plug = plug;
- }
+ tsk->plug = plug;
}
EXPORT_SYMBOL(blk_start_plug);
@@ -3195,10 +3130,11 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
void blk_finish_plug(struct blk_plug *plug)
{
+ if (plug != current->plug)
+ return;
blk_flush_plug_list(plug, false);
- if (plug == current->plug)
- current->plug = NULL;
+ current->plug = NULL;
}
EXPORT_SYMBOL(blk_finish_plug);
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 9924725fa50d..3fec8a29d0fa 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -53,7 +53,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
rq_end_io_fn *done)
{
int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
- bool is_pm_resume;
WARN_ON(irqs_disabled());
WARN_ON(rq->cmd_type == REQ_TYPE_FS);
@@ -70,12 +69,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
return;
}
- /*
- * need to check this before __blk_run_queue(), because rq can
- * be freed before that returns.
- */
- is_pm_resume = rq->cmd_type == REQ_TYPE_PM_RESUME;
-
spin_lock_irq(q->queue_lock);
if (unlikely(blk_queue_dying(q))) {
@@ -88,9 +81,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
__elv_add_request(q, rq, where);
__blk_run_queue(q);
- /* the queue is stopped so it won't be run */
- if (is_pm_resume)
- __blk_run_queue_uncond(q);
spin_unlock_irq(q->queue_lock);
}
EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index fd3fee81c23c..30a0d9f89017 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -589,7 +589,8 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
!blk_write_same_mergeable(rq->bio, bio))
return false;
- if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS)) {
+ /* Only check gaps if the bio carries data */
+ if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && bio_has_data(bio)) {
struct bio_vec *bprev;
bprev = &rq->biotail->bi_io_vec[rq->biotail->bi_vcnt - 1];
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index be3290cc0644..9b6e28830b82 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -438,6 +438,39 @@ static void bt_for_each(struct blk_mq_hw_ctx *hctx,
}
}
+static void bt_tags_for_each(struct blk_mq_tags *tags,
+ struct blk_mq_bitmap_tags *bt, unsigned int off,
+ busy_tag_iter_fn *fn, void *data, bool reserved)
+{
+ struct request *rq;
+ int bit, i;
+
+ if (!tags->rqs)
+ return;
+ for (i = 0; i < bt->map_nr; i++) {
+ struct blk_align_bitmap *bm = &bt->map[i];
+
+ for (bit = find_first_bit(&bm->word, bm->depth);
+ bit < bm->depth;
+ bit = find_next_bit(&bm->word, bm->depth, bit + 1)) {
+ rq = blk_mq_tag_to_rq(tags, off + bit);
+ fn(rq, data, reserved);
+ }
+
+ off += (1 << bt->bits_per_word);
+ }
+}
+
+void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+ void *priv)
+{
+ if (tags->nr_reserved_tags)
+ bt_tags_for_each(tags, &tags->breserved_tags, 0, fn, priv, true);
+ bt_tags_for_each(tags, &tags->bitmap_tags, tags->nr_reserved_tags, fn, priv,
+ false);
+}
+EXPORT_SYMBOL(blk_mq_all_tag_busy_iter);
+
void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
void *priv)
{
@@ -580,6 +613,11 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
if (!tags)
return NULL;
+ if (!zalloc_cpumask_var(&tags->cpumask, GFP_KERNEL)) {
+ kfree(tags);
+ return NULL;
+ }
+
tags->nr_tags = total_tags;
tags->nr_reserved_tags = reserved_tags;
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 90767b370308..75893a34237d 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -44,6 +44,7 @@ struct blk_mq_tags {
struct list_head page_list;
int alloc_policy;
+ cpumask_var_t cpumask;
};
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 594eea04266e..f53779692c77 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -89,7 +89,8 @@ static int blk_mq_queue_enter(struct request_queue *q, gfp_t gfp)
return -EBUSY;
ret = wait_event_interruptible(q->mq_freeze_wq,
- !q->mq_freeze_depth || blk_queue_dying(q));
+ !atomic_read(&q->mq_freeze_depth) ||
+ blk_queue_dying(q));
if (blk_queue_dying(q))
return -ENODEV;
if (ret)
@@ -112,13 +113,10 @@ static void blk_mq_usage_counter_release(struct percpu_ref *ref)
void blk_mq_freeze_queue_start(struct request_queue *q)
{
- bool freeze;
+ int freeze_depth;
- spin_lock_irq(q->queue_lock);
- freeze = !q->mq_freeze_depth++;
- spin_unlock_irq(q->queue_lock);
-
- if (freeze) {
+ freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
+ if (freeze_depth == 1) {
percpu_ref_kill(&q->mq_usage_counter);
blk_mq_run_hw_queues(q, false);
}
@@ -143,13 +141,11 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
void blk_mq_unfreeze_queue(struct request_queue *q)
{
- bool wake;
+ int freeze_depth;
- spin_lock_irq(q->queue_lock);
- wake = !--q->mq_freeze_depth;
- WARN_ON_ONCE(q->mq_freeze_depth < 0);
- spin_unlock_irq(q->queue_lock);
- if (wake) {
+ freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
+ WARN_ON_ONCE(freeze_depth < 0);
+ if (!freeze_depth) {
percpu_ref_reinit(&q->mq_usage_counter);
wake_up_all(&q->mq_freeze_wq);
}
@@ -1237,6 +1233,38 @@ static struct request *blk_mq_map_request(struct request_queue *q,
return rq;
}
+static int blk_mq_direct_issue_request(struct request *rq)
+{
+ int ret;
+ struct request_queue *q = rq->q;
+ struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q,
+ rq->mq_ctx->cpu);
+ struct blk_mq_queue_data bd = {
+ .rq = rq,
+ .list = NULL,
+ .last = 1
+ };
+
+ /*
+ * For OK queue, we are done. For error, kill it. Any other
+ * error (busy), just add it to our list as we previously
+ * would have done
+ */
+ ret = q->mq_ops->queue_rq(hctx, &bd);
+ if (ret == BLK_MQ_RQ_QUEUE_OK)
+ return 0;
+ else {
+ __blk_mq_requeue_request(rq);
+
+ if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
+ rq->errors = -EIO;
+ blk_mq_end_request(rq, rq->errors);
+ return 0;
+ }
+ return -1;
+ }
+}
+
/*
* Multiple hardware queue variant. This will not use per-process plugs,
* but will attempt to bypass the hctx queueing if we can go straight to
@@ -1248,6 +1276,9 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
struct blk_map_ctx data;
struct request *rq;
+ unsigned int request_count = 0;
+ struct blk_plug *plug;
+ struct request *same_queue_rq = NULL;
blk_queue_bounce(q, &bio);
@@ -1256,6 +1287,10 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
return;
}
+ if (!is_flush_fua && !blk_queue_nomerges(q) &&
+ blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
+ return;
+
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
return;
@@ -1266,38 +1301,42 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
goto run_queue;
}
+ plug = current->plug;
/*
* If the driver supports defer issued based on 'last', then
* queue it up like normal since we can potentially save some
* CPU this way.
*/
- if (is_sync && !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
- struct blk_mq_queue_data bd = {
- .rq = rq,
- .list = NULL,
- .last = 1
- };
- int ret;
+ if (((plug && !blk_queue_nomerges(q)) || is_sync) &&
+ !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
+ struct request *old_rq = NULL;
blk_mq_bio_to_request(rq, bio);
/*
- * For OK queue, we are done. For error, kill it. Any other
- * error (busy), just add it to our list as we previously
- * would have done
+ * we do limited pluging. If bio can be merged, do merge.
+ * Otherwise the existing request in the plug list will be
+ * issued. So the plug list will have one request at most
*/
- ret = q->mq_ops->queue_rq(data.hctx, &bd);
- if (ret == BLK_MQ_RQ_QUEUE_OK)
- goto done;
- else {
- __blk_mq_requeue_request(rq);
-
- if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
- rq->errors = -EIO;
- blk_mq_end_request(rq, rq->errors);
- goto done;
+ if (plug) {
+ /*
+ * The plug list might get flushed before this. If that
+ * happens, same_queue_rq is invalid and plug list is empty
+ **/
+ if (same_queue_rq && !list_empty(&plug->mq_list)) {
+ old_rq = same_queue_rq;
+ list_del_init(&old_rq->queuelist);
}
- }
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+ } else /* is_sync */
+ old_rq = rq;
+ blk_mq_put_ctx(data.ctx);
+ if (!old_rq)
+ return;
+ if (!blk_mq_direct_issue_request(old_rq))
+ return;
+ blk_mq_insert_request(old_rq, false, true, true);
+ return;
}
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
@@ -1310,7 +1349,6 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
run_queue:
blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
}
-done:
blk_mq_put_ctx(data.ctx);
}
@@ -1322,16 +1360,11 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
{
const int is_sync = rw_is_sync(bio->bi_rw);
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
- unsigned int use_plug, request_count = 0;
+ struct blk_plug *plug;
+ unsigned int request_count = 0;
struct blk_map_ctx data;
struct request *rq;
- /*
- * If we have multiple hardware queues, just go directly to
- * one of those for sync IO.
- */
- use_plug = !is_flush_fua && !is_sync;
-
blk_queue_bounce(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
@@ -1339,8 +1372,8 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
return;
}
- if (use_plug && !blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count))
+ if (!is_flush_fua && !blk_queue_nomerges(q) &&
+ blk_attempt_plug_merge(q, bio, &request_count, NULL))
return;
rq = blk_mq_map_request(q, bio, &data);
@@ -1358,21 +1391,18 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
* utilize that to temporarily store requests until the task is
* either done or scheduled away.
*/
- if (use_plug) {
- struct blk_plug *plug = current->plug;
-
- if (plug) {
- blk_mq_bio_to_request(rq, bio);
- if (list_empty(&plug->mq_list))
- trace_block_plug(q);
- else if (request_count >= BLK_MAX_REQUEST_COUNT) {
- blk_flush_plug_list(plug, false);
- trace_block_plug(q);
- }
- list_add_tail(&rq->queuelist, &plug->mq_list);
- blk_mq_put_ctx(data.ctx);
- return;
+ plug = current->plug;
+ if (plug) {
+ blk_mq_bio_to_request(rq, bio);
+ if (list_empty(&plug->mq_list))
+ trace_block_plug(q);
+ else if (request_count >= BLK_MAX_REQUEST_COUNT) {
+ blk_flush_plug_list(plug, false);
+ trace_block_plug(q);
}
+ list_add_tail(&rq->queuelist, &plug->mq_list);
+ blk_mq_put_ctx(data.ctx);
+ return;
}
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
@@ -1508,7 +1538,6 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
i++;
}
}
-
return tags;
fail:
@@ -1792,6 +1821,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
hctx = q->mq_ops->map_queue(q, i);
cpumask_set_cpu(i, hctx->cpumask);
+ cpumask_set_cpu(i, hctx->tags->cpumask);
ctx->index_hw = hctx->nr_ctx;
hctx->ctxs[hctx->nr_ctx++] = ctx;
}
@@ -2056,7 +2086,7 @@ void blk_mq_free_queue(struct request_queue *q)
/* Basically redo blk_mq_init_queue with queue frozen */
static void blk_mq_queue_reinit(struct request_queue *q)
{
- WARN_ON_ONCE(!q->mq_freeze_depth);
+ WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
blk_mq_sysfs_unregister(q);
@@ -2173,6 +2203,12 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
return 0;
}
+struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags)
+{
+ return tags->cpumask;
+}
+EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask);
+
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
@@ -2234,8 +2270,10 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
int i;
for (i = 0; i < set->nr_hw_queues; i++) {
- if (set->tags[i])
+ if (set->tags[i]) {
blk_mq_free_rq_map(set, set->tags[i], i);
+ free_cpumask_var(set->tags[i]->cpumask);
+ }
}
kfree(set->tags);
diff --git a/block/blk.h b/block/blk.h
index 43b036185712..026d9594142b 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -78,7 +78,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
struct bio *bio);
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- unsigned int *request_count);
+ unsigned int *request_count,
+ struct request **same_queue_rq);
void blk_account_io_start(struct request *req, bool new_io);
void blk_account_io_completion(struct request *req, unsigned int bytes);
@@ -193,8 +194,6 @@ int blk_try_merge(struct request *rq, struct bio *bio);
void blk_queue_congestion_threshold(struct request_queue *q);
-void __blk_run_queue_uncond(struct request_queue *q);
-
int blk_dev_init(void);
diff --git a/block/bounce.c b/block/bounce.c
index ed9dd8067120..3ab0bce1c947 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -128,9 +128,6 @@ static void bounce_end_io(struct bio *bio, mempool_t *pool, int err)
struct bio_vec *bvec, *org_vec;
int i;
- if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
- set_bit(BIO_EOPNOTSUPP, &bio_orig->bi_flags);
-
/*
* free up bounce indirect pages used
*/
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 5da8e6e9ab4b..d8ad45ccd8fa 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -67,6 +67,11 @@ static struct kmem_cache *cfq_pool;
#define sample_valid(samples) ((samples) > 80)
#define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node)
+/* blkio-related constants */
+#define CFQ_WEIGHT_MIN 10
+#define CFQ_WEIGHT_MAX 1000
+#define CFQ_WEIGHT_DEFAULT 500
+
struct cfq_ttime {
unsigned long last_end_request;
@@ -212,6 +217,15 @@ struct cfqg_stats {
#endif /* CONFIG_CFQ_GROUP_IOSCHED */
};
+/* Per-cgroup data */
+struct cfq_group_data {
+ /* must be the first member */
+ struct blkcg_policy_data pd;
+
+ unsigned int weight;
+ unsigned int leaf_weight;
+};
+
/* This is per cgroup per device grouping structure */
struct cfq_group {
/* must be the first member */
@@ -446,16 +460,6 @@ CFQ_CFQQ_FNS(deep);
CFQ_CFQQ_FNS(wait_busy);
#undef CFQ_CFQQ_FNS
-static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
-{
- return pd ? container_of(pd, struct cfq_group, pd) : NULL;
-}
-
-static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
-{
- return pd_to_blkg(&cfqg->pd);
-}
-
#if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
/* cfqg stats flags */
@@ -600,6 +604,22 @@ static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { }
#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
+{
+ return pd ? container_of(pd, struct cfq_group, pd) : NULL;
+}
+
+static struct cfq_group_data
+*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
+{
+ return cpd ? container_of(cpd, struct cfq_group_data, pd) : NULL;
+}
+
+static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
+{
+ return pd_to_blkg(&cfqg->pd);
+}
+
static struct blkcg_policy blkcg_policy_cfq;
static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
@@ -607,6 +627,11 @@ static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg)
return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq));
}
+static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg)
+{
+ return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq));
+}
+
static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg)
{
struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent;
@@ -1544,13 +1569,28 @@ static void cfqg_stats_init(struct cfqg_stats *stats)
#endif
}
+static void cfq_cpd_init(const struct blkcg *blkcg)
+{
+ struct cfq_group_data *cgd =
+ cpd_to_cfqgd(blkcg->pd[blkcg_policy_cfq.plid]);
+
+ if (blkcg == &blkcg_root) {
+ cgd->weight = 2 * CFQ_WEIGHT_DEFAULT;
+ cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
+ } else {
+ cgd->weight = CFQ_WEIGHT_DEFAULT;
+ cgd->leaf_weight = CFQ_WEIGHT_DEFAULT;
+ }
+}
+
static void cfq_pd_init(struct blkcg_gq *blkg)
{
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);
cfq_init_cfqg_base(cfqg);
- cfqg->weight = blkg->blkcg->cfq_weight;
- cfqg->leaf_weight = blkg->blkcg->cfq_leaf_weight;
+ cfqg->weight = cgd->weight;
+ cfqg->leaf_weight = cgd->leaf_weight;
cfqg_stats_init(&cfqg->stats);
cfqg_stats_init(&cfqg->dead_stats);
}
@@ -1673,13 +1713,27 @@ static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
static int cfq_print_weight(struct seq_file *sf, void *v)
{
- seq_printf(sf, "%u\n", css_to_blkcg(seq_css(sf))->cfq_weight);
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+ unsigned int val = 0;
+
+ if (cgd)
+ val = cgd->weight;
+
+ seq_printf(sf, "%u\n", val);
return 0;
}
static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
{
- seq_printf(sf, "%u\n", css_to_blkcg(seq_css(sf))->cfq_leaf_weight);
+ struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+ unsigned int val = 0;
+
+ if (cgd)
+ val = cgd->leaf_weight;
+
+ seq_printf(sf, "%u\n", val);
return 0;
}
@@ -1690,6 +1744,7 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
struct blkcg *blkcg = css_to_blkcg(of_css(of));
struct blkg_conf_ctx ctx;
struct cfq_group *cfqg;
+ struct cfq_group_data *cfqgd;
int ret;
ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx);
@@ -1698,17 +1753,22 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
ret = -EINVAL;
cfqg = blkg_to_cfqg(ctx.blkg);
+ cfqgd = blkcg_to_cfqgd(blkcg);
+ if (!cfqg || !cfqgd)
+ goto err;
+
if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) {
if (!is_leaf_weight) {
cfqg->dev_weight = ctx.v;
- cfqg->new_weight = ctx.v ?: blkcg->cfq_weight;
+ cfqg->new_weight = ctx.v ?: cfqgd->weight;
} else {
cfqg->dev_leaf_weight = ctx.v;
- cfqg->new_leaf_weight = ctx.v ?: blkcg->cfq_leaf_weight;
+ cfqg->new_leaf_weight = ctx.v ?: cfqgd->leaf_weight;
}
ret = 0;
}
+err:
blkg_conf_finish(&ctx);
return ret ?: nbytes;
}
@@ -1730,16 +1790,23 @@ static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
{
struct blkcg *blkcg = css_to_blkcg(css);
struct blkcg_gq *blkg;
+ struct cfq_group_data *cfqgd;
+ int ret = 0;
if (val < CFQ_WEIGHT_MIN || val > CFQ_WEIGHT_MAX)
return -EINVAL;
spin_lock_irq(&blkcg->lock);
+ cfqgd = blkcg_to_cfqgd(blkcg);
+ if (!cfqgd) {
+ ret = -EINVAL;
+ goto out;
+ }
if (!is_leaf_weight)
- blkcg->cfq_weight = val;
+ cfqgd->weight = val;
else
- blkcg->cfq_leaf_weight = val;
+ cfqgd->leaf_weight = val;
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
@@ -1749,15 +1816,16 @@ static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
if (!is_leaf_weight) {
if (!cfqg->dev_weight)
- cfqg->new_weight = blkcg->cfq_weight;
+ cfqg->new_weight = cfqgd->weight;
} else {
if (!cfqg->dev_leaf_weight)
- cfqg->new_leaf_weight = blkcg->cfq_leaf_weight;
+ cfqg->new_leaf_weight = cfqgd->leaf_weight;
}
}
+out:
spin_unlock_irq(&blkcg->lock);
- return 0;
+ return ret;
}
static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
@@ -4477,6 +4545,18 @@ out_free:
return ret;
}
+static void cfq_registered_queue(struct request_queue *q)
+{
+ struct elevator_queue *e = q->elevator;
+ struct cfq_data *cfqd = e->elevator_data;
+
+ /*
+ * Default to IOPS mode with no idling for SSDs
+ */
+ if (blk_queue_nonrot(q))
+ cfqd->cfq_slice_idle = 0;
+}
+
/*
* sysfs parts below -->
*/
@@ -4592,6 +4672,7 @@ static struct elevator_type iosched_cfq = {
.elevator_may_queue_fn = cfq_may_queue,
.elevator_init_fn = cfq_init_queue,
.elevator_exit_fn = cfq_exit_queue,
+ .elevator_registered_fn = cfq_registered_queue,
},
.icq_size = sizeof(struct cfq_io_cq),
.icq_align = __alignof__(struct cfq_io_cq),
@@ -4603,8 +4684,10 @@ static struct elevator_type iosched_cfq = {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static struct blkcg_policy blkcg_policy_cfq = {
.pd_size = sizeof(struct cfq_group),
+ .cpd_size = sizeof(struct cfq_group_data),
.cftypes = cfq_blkcg_files,
+ .cpd_init_fn = cfq_cpd_init,
.pd_init_fn = cfq_pd_init,
.pd_offline_fn = cfq_pd_offline,
.pd_reset_stats_fn = cfq_pd_reset_stats,
diff --git a/block/elevator.c b/block/elevator.c
index 8985038f398c..942579d04128 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -806,6 +806,8 @@ int elv_register_queue(struct request_queue *q)
}
kobject_uevent(&e->kobj, KOBJ_ADD);
e->registered = 1;
+ if (e->type->ops.elevator_registered_fn)
+ e->type->ops.elevator_registered_fn(q);
}
return error;
}
diff --git a/block/ioctl.c b/block/ioctl.c
index 7d8befde2aca..8061eba42887 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -150,21 +150,48 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
}
}
-static int blkdev_reread_part(struct block_device *bdev)
+/*
+ * This is an exported API for the block driver, and will not
+ * acquire bd_mutex. This API should be used in case that
+ * caller has held bd_mutex already.
+ */
+int __blkdev_reread_part(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
- int res;
if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- if (!mutex_trylock(&bdev->bd_mutex))
- return -EBUSY;
- res = rescan_partitions(disk, bdev);
+
+ lockdep_assert_held(&bdev->bd_mutex);
+
+ return rescan_partitions(disk, bdev);
+}
+EXPORT_SYMBOL(__blkdev_reread_part);
+
+/*
+ * This is an exported API for the block driver, and will
+ * try to acquire bd_mutex. If bd_mutex has been held already
+ * in current context, please call __blkdev_reread_part().
+ *
+ * Make sure the held locks in current context aren't required
+ * in open()/close() handler and I/O path for avoiding ABBA deadlock:
+ * - bd_mutex is held before calling block driver's open/close
+ * handler
+ * - reading partition table may submit I/O to the block device
+ */
+int blkdev_reread_part(struct block_device *bdev)
+{
+ int res;
+
+ mutex_lock(&bdev->bd_mutex);
+ res = __blkdev_reread_part(bdev);
mutex_unlock(&bdev->bd_mutex);
+
return res;
}
+EXPORT_SYMBOL(blkdev_reread_part);
static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
uint64_t len, int secure)