Commit bfffa1cc authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
  ...
parents cc8a0a94 ae994ea9

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -2075,6 +2075,7 @@ M: Jens Axboe <axboe@kernel.dk> 
T:	git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git

S:	Maintained

F:	block/

F:	kernel/trace/blktrace.c



BLOCK2MTD DRIVER

M:	Joern Engel <joern@lazybastard.org>

block/bio-integrity.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

	}

block/bio.c

+47 −30
Original line number Diff line number Diff line
@@ -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);
@@ -293,7 +293,7 @@ void bio_reset(struct bio *bio) 


	memset(bio, 0, BIO_RESET_BYTES);

	bio->bi_flags = flags | (1 << BIO_UPTODATE);

	atomic_set(&bio->bi_remaining, 1);

	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);
@@ -524,14 +535,18 @@ EXPORT_SYMBOL(zero_fill_bio); 
 **/

void bio_put(struct bio *bio)

{

	BIO_BUG_ON(!atomic_read(&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))

		if (atomic_dec_and_test(&bio->__bi_cnt))

			bio_free(bio);

	}

}

EXPORT_SYMBOL(bio_put);



inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
@@ -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,
@@ -1789,21 +1821,6 @@ 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

block/blk-cgroup.c

+81 −11
Original line number Diff line number Diff line
@@ -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);

	}

block/blk-cgroup.h

+32 −8
Original line number Diff line number Diff line
@@ -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 {

};

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