![Mike Snitzer](/assets/img/avatar_default.png)
Allow user to change the number of IOs that are reserved by bio-based DM's mempools by writing to this file: /sys/module/dm_mod/parameters/reserved_bio_based_ios The default value is RESERVED_BIO_BASED_IOS (16). The maximum allowed value is RESERVED_MAX_IOS (1024). Export dm_get_reserved_bio_based_ios() for use by DM targets and core code. Switch to sizing dm-io's mempool and bioset using DM core's configurable 'reserved_bio_based_ios'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Frank Mayhar <fmayhar@google.com>
2993 lines
67 KiB
C
2993 lines
67 KiB
C
/*
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* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
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* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#include "dm.h"
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#include "dm-uevent.h"
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/moduleparam.h>
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#include <linux/blkpg.h>
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#include <linux/bio.h>
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#include <linux/mempool.h>
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#include <linux/slab.h>
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#include <linux/idr.h>
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#include <linux/hdreg.h>
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#include <linux/delay.h>
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#include <trace/events/block.h>
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#define DM_MSG_PREFIX "core"
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#ifdef CONFIG_PRINTK
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/*
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* ratelimit state to be used in DMXXX_LIMIT().
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*/
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DEFINE_RATELIMIT_STATE(dm_ratelimit_state,
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DEFAULT_RATELIMIT_INTERVAL,
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DEFAULT_RATELIMIT_BURST);
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EXPORT_SYMBOL(dm_ratelimit_state);
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#endif
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/*
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* Cookies are numeric values sent with CHANGE and REMOVE
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* uevents while resuming, removing or renaming the device.
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*/
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#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
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#define DM_COOKIE_LENGTH 24
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static const char *_name = DM_NAME;
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static unsigned int major = 0;
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static unsigned int _major = 0;
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static DEFINE_IDR(_minor_idr);
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static DEFINE_SPINLOCK(_minor_lock);
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/*
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* For bio-based dm.
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* One of these is allocated per bio.
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*/
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struct dm_io {
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struct mapped_device *md;
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int error;
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atomic_t io_count;
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struct bio *bio;
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unsigned long start_time;
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spinlock_t endio_lock;
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struct dm_stats_aux stats_aux;
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};
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/*
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* For request-based dm.
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* One of these is allocated per request.
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*/
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struct dm_rq_target_io {
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struct mapped_device *md;
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struct dm_target *ti;
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struct request *orig, clone;
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int error;
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union map_info info;
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};
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/*
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* For request-based dm - the bio clones we allocate are embedded in these
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* structs.
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*
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* We allocate these with bio_alloc_bioset, using the front_pad parameter when
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* the bioset is created - this means the bio has to come at the end of the
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* struct.
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*/
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struct dm_rq_clone_bio_info {
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struct bio *orig;
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struct dm_rq_target_io *tio;
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struct bio clone;
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};
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union map_info *dm_get_mapinfo(struct bio *bio)
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{
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if (bio && bio->bi_private)
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return &((struct dm_target_io *)bio->bi_private)->info;
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return NULL;
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}
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union map_info *dm_get_rq_mapinfo(struct request *rq)
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{
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if (rq && rq->end_io_data)
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return &((struct dm_rq_target_io *)rq->end_io_data)->info;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(dm_get_rq_mapinfo);
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#define MINOR_ALLOCED ((void *)-1)
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/*
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* Bits for the md->flags field.
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*/
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#define DMF_BLOCK_IO_FOR_SUSPEND 0
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#define DMF_SUSPENDED 1
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#define DMF_FROZEN 2
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#define DMF_FREEING 3
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#define DMF_DELETING 4
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#define DMF_NOFLUSH_SUSPENDING 5
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#define DMF_MERGE_IS_OPTIONAL 6
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/*
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* A dummy definition to make RCU happy.
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* struct dm_table should never be dereferenced in this file.
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*/
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struct dm_table {
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int undefined__;
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};
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/*
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* Work processed by per-device workqueue.
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*/
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struct mapped_device {
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struct srcu_struct io_barrier;
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struct mutex suspend_lock;
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atomic_t holders;
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atomic_t open_count;
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/*
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* The current mapping.
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* Use dm_get_live_table{_fast} or take suspend_lock for
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* dereference.
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*/
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struct dm_table *map;
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unsigned long flags;
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struct request_queue *queue;
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unsigned type;
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/* Protect queue and type against concurrent access. */
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struct mutex type_lock;
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struct target_type *immutable_target_type;
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struct gendisk *disk;
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char name[16];
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void *interface_ptr;
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/*
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* A list of ios that arrived while we were suspended.
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*/
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atomic_t pending[2];
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wait_queue_head_t wait;
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struct work_struct work;
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struct bio_list deferred;
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spinlock_t deferred_lock;
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/*
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* Processing queue (flush)
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*/
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struct workqueue_struct *wq;
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/*
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* io objects are allocated from here.
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*/
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mempool_t *io_pool;
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struct bio_set *bs;
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/*
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* Event handling.
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*/
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atomic_t event_nr;
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wait_queue_head_t eventq;
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atomic_t uevent_seq;
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struct list_head uevent_list;
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spinlock_t uevent_lock; /* Protect access to uevent_list */
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/*
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* freeze/thaw support require holding onto a super block
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*/
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struct super_block *frozen_sb;
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struct block_device *bdev;
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/* forced geometry settings */
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struct hd_geometry geometry;
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/* sysfs handle */
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struct kobject kobj;
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/* zero-length flush that will be cloned and submitted to targets */
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struct bio flush_bio;
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struct dm_stats stats;
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};
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/*
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* For mempools pre-allocation at the table loading time.
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*/
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struct dm_md_mempools {
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mempool_t *io_pool;
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struct bio_set *bs;
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};
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#define RESERVED_BIO_BASED_IOS 16
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#define RESERVED_REQUEST_BASED_IOS 256
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#define RESERVED_MAX_IOS 1024
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static struct kmem_cache *_io_cache;
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static struct kmem_cache *_rq_tio_cache;
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/*
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* Bio-based DM's mempools' reserved IOs set by the user.
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*/
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static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
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/*
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* Request-based DM's mempools' reserved IOs set by the user.
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*/
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static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
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static unsigned __dm_get_reserved_ios(unsigned *reserved_ios,
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unsigned def, unsigned max)
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{
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unsigned ios = ACCESS_ONCE(*reserved_ios);
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unsigned modified_ios = 0;
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if (!ios)
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modified_ios = def;
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else if (ios > max)
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modified_ios = max;
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if (modified_ios) {
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(void)cmpxchg(reserved_ios, ios, modified_ios);
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ios = modified_ios;
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}
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return ios;
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}
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unsigned dm_get_reserved_bio_based_ios(void)
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{
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return __dm_get_reserved_ios(&reserved_bio_based_ios,
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RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS);
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}
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EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
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unsigned dm_get_reserved_rq_based_ios(void)
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{
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return __dm_get_reserved_ios(&reserved_rq_based_ios,
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RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS);
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}
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EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
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static int __init local_init(void)
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{
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int r = -ENOMEM;
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/* allocate a slab for the dm_ios */
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_io_cache = KMEM_CACHE(dm_io, 0);
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if (!_io_cache)
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return r;
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_rq_tio_cache = KMEM_CACHE(dm_rq_target_io, 0);
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if (!_rq_tio_cache)
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goto out_free_io_cache;
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r = dm_uevent_init();
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if (r)
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goto out_free_rq_tio_cache;
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_major = major;
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r = register_blkdev(_major, _name);
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if (r < 0)
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goto out_uevent_exit;
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if (!_major)
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_major = r;
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return 0;
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out_uevent_exit:
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dm_uevent_exit();
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out_free_rq_tio_cache:
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kmem_cache_destroy(_rq_tio_cache);
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out_free_io_cache:
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kmem_cache_destroy(_io_cache);
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return r;
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}
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static void local_exit(void)
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{
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kmem_cache_destroy(_rq_tio_cache);
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kmem_cache_destroy(_io_cache);
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unregister_blkdev(_major, _name);
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dm_uevent_exit();
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_major = 0;
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DMINFO("cleaned up");
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}
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static int (*_inits[])(void) __initdata = {
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local_init,
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dm_target_init,
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dm_linear_init,
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dm_stripe_init,
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dm_io_init,
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dm_kcopyd_init,
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dm_interface_init,
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dm_statistics_init,
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};
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static void (*_exits[])(void) = {
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local_exit,
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dm_target_exit,
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dm_linear_exit,
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dm_stripe_exit,
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dm_io_exit,
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dm_kcopyd_exit,
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dm_interface_exit,
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dm_statistics_exit,
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};
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static int __init dm_init(void)
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{
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const int count = ARRAY_SIZE(_inits);
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int r, i;
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for (i = 0; i < count; i++) {
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r = _inits[i]();
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if (r)
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goto bad;
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}
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return 0;
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bad:
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while (i--)
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_exits[i]();
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return r;
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}
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static void __exit dm_exit(void)
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{
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int i = ARRAY_SIZE(_exits);
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while (i--)
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_exits[i]();
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/*
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* Should be empty by this point.
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*/
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idr_destroy(&_minor_idr);
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}
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/*
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* Block device functions
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*/
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int dm_deleting_md(struct mapped_device *md)
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{
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return test_bit(DMF_DELETING, &md->flags);
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}
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static int dm_blk_open(struct block_device *bdev, fmode_t mode)
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{
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struct mapped_device *md;
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spin_lock(&_minor_lock);
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md = bdev->bd_disk->private_data;
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if (!md)
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goto out;
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if (test_bit(DMF_FREEING, &md->flags) ||
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dm_deleting_md(md)) {
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md = NULL;
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goto out;
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}
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dm_get(md);
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atomic_inc(&md->open_count);
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out:
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spin_unlock(&_minor_lock);
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return md ? 0 : -ENXIO;
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}
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static void dm_blk_close(struct gendisk *disk, fmode_t mode)
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{
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struct mapped_device *md = disk->private_data;
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spin_lock(&_minor_lock);
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atomic_dec(&md->open_count);
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dm_put(md);
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spin_unlock(&_minor_lock);
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}
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int dm_open_count(struct mapped_device *md)
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{
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return atomic_read(&md->open_count);
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}
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/*
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* Guarantees nothing is using the device before it's deleted.
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*/
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int dm_lock_for_deletion(struct mapped_device *md)
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{
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int r = 0;
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spin_lock(&_minor_lock);
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if (dm_open_count(md))
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r = -EBUSY;
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else
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set_bit(DMF_DELETING, &md->flags);
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spin_unlock(&_minor_lock);
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return r;
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}
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sector_t dm_get_size(struct mapped_device *md)
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{
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return get_capacity(md->disk);
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}
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struct dm_stats *dm_get_stats(struct mapped_device *md)
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{
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return &md->stats;
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}
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static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct mapped_device *md = bdev->bd_disk->private_data;
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return dm_get_geometry(md, geo);
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}
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static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
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unsigned int cmd, unsigned long arg)
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{
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struct mapped_device *md = bdev->bd_disk->private_data;
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int srcu_idx;
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struct dm_table *map;
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struct dm_target *tgt;
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int r = -ENOTTY;
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retry:
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map = dm_get_live_table(md, &srcu_idx);
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if (!map || !dm_table_get_size(map))
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goto out;
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/* We only support devices that have a single target */
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if (dm_table_get_num_targets(map) != 1)
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goto out;
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tgt = dm_table_get_target(map, 0);
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if (dm_suspended_md(md)) {
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r = -EAGAIN;
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goto out;
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}
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if (tgt->type->ioctl)
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r = tgt->type->ioctl(tgt, cmd, arg);
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out:
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dm_put_live_table(md, srcu_idx);
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if (r == -ENOTCONN) {
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msleep(10);
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goto retry;
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}
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return r;
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}
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static struct dm_io *alloc_io(struct mapped_device *md)
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{
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return mempool_alloc(md->io_pool, GFP_NOIO);
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}
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static void free_io(struct mapped_device *md, struct dm_io *io)
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{
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mempool_free(io, md->io_pool);
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}
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static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
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{
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bio_put(&tio->clone);
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}
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static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md,
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gfp_t gfp_mask)
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{
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return mempool_alloc(md->io_pool, gfp_mask);
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}
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static void free_rq_tio(struct dm_rq_target_io *tio)
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{
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mempool_free(tio, tio->md->io_pool);
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}
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|
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static int md_in_flight(struct mapped_device *md)
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{
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return atomic_read(&md->pending[READ]) +
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atomic_read(&md->pending[WRITE]);
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}
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|
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static void start_io_acct(struct dm_io *io)
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{
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struct mapped_device *md = io->md;
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struct bio *bio = io->bio;
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int cpu;
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int rw = bio_data_dir(bio);
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io->start_time = jiffies;
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cpu = part_stat_lock();
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part_round_stats(cpu, &dm_disk(md)->part0);
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part_stat_unlock();
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atomic_set(&dm_disk(md)->part0.in_flight[rw],
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atomic_inc_return(&md->pending[rw]));
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if (unlikely(dm_stats_used(&md->stats)))
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dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
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bio_sectors(bio), false, 0, &io->stats_aux);
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}
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static void end_io_acct(struct dm_io *io)
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{
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struct mapped_device *md = io->md;
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struct bio *bio = io->bio;
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unsigned long duration = jiffies - io->start_time;
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int pending, cpu;
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int rw = bio_data_dir(bio);
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cpu = part_stat_lock();
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part_round_stats(cpu, &dm_disk(md)->part0);
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part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
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part_stat_unlock();
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if (unlikely(dm_stats_used(&md->stats)))
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dm_stats_account_io(&md->stats, bio->bi_rw, bio->bi_sector,
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bio_sectors(bio), true, duration, &io->stats_aux);
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|
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/*
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* After this is decremented the bio must not be touched if it is
|
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* a flush.
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*/
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pending = atomic_dec_return(&md->pending[rw]);
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atomic_set(&dm_disk(md)->part0.in_flight[rw], pending);
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pending += atomic_read(&md->pending[rw^0x1]);
|
|
|
|
/* nudge anyone waiting on suspend queue */
|
|
if (!pending)
|
|
wake_up(&md->wait);
|
|
}
|
|
|
|
/*
|
|
* Add the bio to the list of deferred io.
|
|
*/
|
|
static void queue_io(struct mapped_device *md, struct bio *bio)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
bio_list_add(&md->deferred, bio);
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Everyone (including functions in this file), should use this
|
|
* function to access the md->map field, and make sure they call
|
|
* dm_put_live_table() when finished.
|
|
*/
|
|
struct dm_table *dm_get_live_table(struct mapped_device *md, int *srcu_idx) __acquires(md->io_barrier)
|
|
{
|
|
*srcu_idx = srcu_read_lock(&md->io_barrier);
|
|
|
|
return srcu_dereference(md->map, &md->io_barrier);
|
|
}
|
|
|
|
void dm_put_live_table(struct mapped_device *md, int srcu_idx) __releases(md->io_barrier)
|
|
{
|
|
srcu_read_unlock(&md->io_barrier, srcu_idx);
|
|
}
|
|
|
|
void dm_sync_table(struct mapped_device *md)
|
|
{
|
|
synchronize_srcu(&md->io_barrier);
|
|
synchronize_rcu_expedited();
|
|
}
|
|
|
|
/*
|
|
* A fast alternative to dm_get_live_table/dm_put_live_table.
|
|
* The caller must not block between these two functions.
|
|
*/
|
|
static struct dm_table *dm_get_live_table_fast(struct mapped_device *md) __acquires(RCU)
|
|
{
|
|
rcu_read_lock();
|
|
return rcu_dereference(md->map);
|
|
}
|
|
|
|
static void dm_put_live_table_fast(struct mapped_device *md) __releases(RCU)
|
|
{
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* Get the geometry associated with a dm device
|
|
*/
|
|
int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
*geo = md->geometry;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set the geometry of a device.
|
|
*/
|
|
int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
|
|
{
|
|
sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
|
|
|
|
if (geo->start > sz) {
|
|
DMWARN("Start sector is beyond the geometry limits.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
md->geometry = *geo;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* CRUD START:
|
|
* A more elegant soln is in the works that uses the queue
|
|
* merge fn, unfortunately there are a couple of changes to
|
|
* the block layer that I want to make for this. So in the
|
|
* interests of getting something for people to use I give
|
|
* you this clearly demarcated crap.
|
|
*---------------------------------------------------------------*/
|
|
|
|
static int __noflush_suspending(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* Decrements the number of outstanding ios that a bio has been
|
|
* cloned into, completing the original io if necc.
|
|
*/
|
|
static void dec_pending(struct dm_io *io, int error)
|
|
{
|
|
unsigned long flags;
|
|
int io_error;
|
|
struct bio *bio;
|
|
struct mapped_device *md = io->md;
|
|
|
|
/* Push-back supersedes any I/O errors */
|
|
if (unlikely(error)) {
|
|
spin_lock_irqsave(&io->endio_lock, flags);
|
|
if (!(io->error > 0 && __noflush_suspending(md)))
|
|
io->error = error;
|
|
spin_unlock_irqrestore(&io->endio_lock, flags);
|
|
}
|
|
|
|
if (atomic_dec_and_test(&io->io_count)) {
|
|
if (io->error == DM_ENDIO_REQUEUE) {
|
|
/*
|
|
* Target requested pushing back the I/O.
|
|
*/
|
|
spin_lock_irqsave(&md->deferred_lock, flags);
|
|
if (__noflush_suspending(md))
|
|
bio_list_add_head(&md->deferred, io->bio);
|
|
else
|
|
/* noflush suspend was interrupted. */
|
|
io->error = -EIO;
|
|
spin_unlock_irqrestore(&md->deferred_lock, flags);
|
|
}
|
|
|
|
io_error = io->error;
|
|
bio = io->bio;
|
|
end_io_acct(io);
|
|
free_io(md, io);
|
|
|
|
if (io_error == DM_ENDIO_REQUEUE)
|
|
return;
|
|
|
|
if ((bio->bi_rw & REQ_FLUSH) && bio->bi_size) {
|
|
/*
|
|
* Preflush done for flush with data, reissue
|
|
* without REQ_FLUSH.
|
|
*/
|
|
bio->bi_rw &= ~REQ_FLUSH;
|
|
queue_io(md, bio);
|
|
} else {
|
|
/* done with normal IO or empty flush */
|
|
trace_block_bio_complete(md->queue, bio, io_error);
|
|
bio_endio(bio, io_error);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void clone_endio(struct bio *bio, int error)
|
|
{
|
|
int r = 0;
|
|
struct dm_target_io *tio = bio->bi_private;
|
|
struct dm_io *io = tio->io;
|
|
struct mapped_device *md = tio->io->md;
|
|
dm_endio_fn endio = tio->ti->type->end_io;
|
|
|
|
if (!bio_flagged(bio, BIO_UPTODATE) && !error)
|
|
error = -EIO;
|
|
|
|
if (endio) {
|
|
r = endio(tio->ti, bio, error);
|
|
if (r < 0 || r == DM_ENDIO_REQUEUE)
|
|
/*
|
|
* error and requeue request are handled
|
|
* in dec_pending().
|
|
*/
|
|
error = r;
|
|
else if (r == DM_ENDIO_INCOMPLETE)
|
|
/* The target will handle the io */
|
|
return;
|
|
else if (r) {
|
|
DMWARN("unimplemented target endio return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
free_tio(md, tio);
|
|
dec_pending(io, error);
|
|
}
|
|
|
|
/*
|
|
* Partial completion handling for request-based dm
|
|
*/
|
|
static void end_clone_bio(struct bio *clone, int error)
|
|
{
|
|
struct dm_rq_clone_bio_info *info = clone->bi_private;
|
|
struct dm_rq_target_io *tio = info->tio;
|
|
struct bio *bio = info->orig;
|
|
unsigned int nr_bytes = info->orig->bi_size;
|
|
|
|
bio_put(clone);
|
|
|
|
if (tio->error)
|
|
/*
|
|
* An error has already been detected on the request.
|
|
* Once error occurred, just let clone->end_io() handle
|
|
* the remainder.
|
|
*/
|
|
return;
|
|
else if (error) {
|
|
/*
|
|
* Don't notice the error to the upper layer yet.
|
|
* The error handling decision is made by the target driver,
|
|
* when the request is completed.
|
|
*/
|
|
tio->error = error;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* I/O for the bio successfully completed.
|
|
* Notice the data completion to the upper layer.
|
|
*/
|
|
|
|
/*
|
|
* bios are processed from the head of the list.
|
|
* So the completing bio should always be rq->bio.
|
|
* If it's not, something wrong is happening.
|
|
*/
|
|
if (tio->orig->bio != bio)
|
|
DMERR("bio completion is going in the middle of the request");
|
|
|
|
/*
|
|
* Update the original request.
|
|
* Do not use blk_end_request() here, because it may complete
|
|
* the original request before the clone, and break the ordering.
|
|
*/
|
|
blk_update_request(tio->orig, 0, nr_bytes);
|
|
}
|
|
|
|
/*
|
|
* Don't touch any member of the md after calling this function because
|
|
* the md may be freed in dm_put() at the end of this function.
|
|
* Or do dm_get() before calling this function and dm_put() later.
|
|
*/
|
|
static void rq_completed(struct mapped_device *md, int rw, int run_queue)
|
|
{
|
|
atomic_dec(&md->pending[rw]);
|
|
|
|
/* nudge anyone waiting on suspend queue */
|
|
if (!md_in_flight(md))
|
|
wake_up(&md->wait);
|
|
|
|
/*
|
|
* Run this off this callpath, as drivers could invoke end_io while
|
|
* inside their request_fn (and holding the queue lock). Calling
|
|
* back into ->request_fn() could deadlock attempting to grab the
|
|
* queue lock again.
|
|
*/
|
|
if (run_queue)
|
|
blk_run_queue_async(md->queue);
|
|
|
|
/*
|
|
* dm_put() must be at the end of this function. See the comment above
|
|
*/
|
|
dm_put(md);
|
|
}
|
|
|
|
static void free_rq_clone(struct request *clone)
|
|
{
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
|
|
blk_rq_unprep_clone(clone);
|
|
free_rq_tio(tio);
|
|
}
|
|
|
|
/*
|
|
* Complete the clone and the original request.
|
|
* Must be called without queue lock.
|
|
*/
|
|
static void dm_end_request(struct request *clone, int error)
|
|
{
|
|
int rw = rq_data_dir(clone);
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
struct mapped_device *md = tio->md;
|
|
struct request *rq = tio->orig;
|
|
|
|
if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
|
|
rq->errors = clone->errors;
|
|
rq->resid_len = clone->resid_len;
|
|
|
|
if (rq->sense)
|
|
/*
|
|
* We are using the sense buffer of the original
|
|
* request.
|
|
* So setting the length of the sense data is enough.
|
|
*/
|
|
rq->sense_len = clone->sense_len;
|
|
}
|
|
|
|
free_rq_clone(clone);
|
|
blk_end_request_all(rq, error);
|
|
rq_completed(md, rw, true);
|
|
}
|
|
|
|
static void dm_unprep_request(struct request *rq)
|
|
{
|
|
struct request *clone = rq->special;
|
|
|
|
rq->special = NULL;
|
|
rq->cmd_flags &= ~REQ_DONTPREP;
|
|
|
|
free_rq_clone(clone);
|
|
}
|
|
|
|
/*
|
|
* Requeue the original request of a clone.
|
|
*/
|
|
void dm_requeue_unmapped_request(struct request *clone)
|
|
{
|
|
int rw = rq_data_dir(clone);
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
struct mapped_device *md = tio->md;
|
|
struct request *rq = tio->orig;
|
|
struct request_queue *q = rq->q;
|
|
unsigned long flags;
|
|
|
|
dm_unprep_request(rq);
|
|
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
blk_requeue_request(q, rq);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
|
|
rq_completed(md, rw, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_requeue_unmapped_request);
|
|
|
|
static void __stop_queue(struct request_queue *q)
|
|
{
|
|
blk_stop_queue(q);
|
|
}
|
|
|
|
static void stop_queue(struct request_queue *q)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
__stop_queue(q);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
}
|
|
|
|
static void __start_queue(struct request_queue *q)
|
|
{
|
|
if (blk_queue_stopped(q))
|
|
blk_start_queue(q);
|
|
}
|
|
|
|
static void start_queue(struct request_queue *q)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(q->queue_lock, flags);
|
|
__start_queue(q);
|
|
spin_unlock_irqrestore(q->queue_lock, flags);
|
|
}
|
|
|
|
static void dm_done(struct request *clone, int error, bool mapped)
|
|
{
|
|
int r = error;
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
dm_request_endio_fn rq_end_io = NULL;
|
|
|
|
if (tio->ti) {
|
|
rq_end_io = tio->ti->type->rq_end_io;
|
|
|
|
if (mapped && rq_end_io)
|
|
r = rq_end_io(tio->ti, clone, error, &tio->info);
|
|
}
|
|
|
|
if (r <= 0)
|
|
/* The target wants to complete the I/O */
|
|
dm_end_request(clone, r);
|
|
else if (r == DM_ENDIO_INCOMPLETE)
|
|
/* The target will handle the I/O */
|
|
return;
|
|
else if (r == DM_ENDIO_REQUEUE)
|
|
/* The target wants to requeue the I/O */
|
|
dm_requeue_unmapped_request(clone);
|
|
else {
|
|
DMWARN("unimplemented target endio return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Request completion handler for request-based dm
|
|
*/
|
|
static void dm_softirq_done(struct request *rq)
|
|
{
|
|
bool mapped = true;
|
|
struct request *clone = rq->completion_data;
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
|
|
if (rq->cmd_flags & REQ_FAILED)
|
|
mapped = false;
|
|
|
|
dm_done(clone, tio->error, mapped);
|
|
}
|
|
|
|
/*
|
|
* Complete the clone and the original request with the error status
|
|
* through softirq context.
|
|
*/
|
|
static void dm_complete_request(struct request *clone, int error)
|
|
{
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
struct request *rq = tio->orig;
|
|
|
|
tio->error = error;
|
|
rq->completion_data = clone;
|
|
blk_complete_request(rq);
|
|
}
|
|
|
|
/*
|
|
* Complete the not-mapped clone and the original request with the error status
|
|
* through softirq context.
|
|
* Target's rq_end_io() function isn't called.
|
|
* This may be used when the target's map_rq() function fails.
|
|
*/
|
|
void dm_kill_unmapped_request(struct request *clone, int error)
|
|
{
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
struct request *rq = tio->orig;
|
|
|
|
rq->cmd_flags |= REQ_FAILED;
|
|
dm_complete_request(clone, error);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_kill_unmapped_request);
|
|
|
|
/*
|
|
* Called with the queue lock held
|
|
*/
|
|
static void end_clone_request(struct request *clone, int error)
|
|
{
|
|
/*
|
|
* For just cleaning up the information of the queue in which
|
|
* the clone was dispatched.
|
|
* The clone is *NOT* freed actually here because it is alloced from
|
|
* dm own mempool and REQ_ALLOCED isn't set in clone->cmd_flags.
|
|
*/
|
|
__blk_put_request(clone->q, clone);
|
|
|
|
/*
|
|
* Actual request completion is done in a softirq context which doesn't
|
|
* hold the queue lock. Otherwise, deadlock could occur because:
|
|
* - another request may be submitted by the upper level driver
|
|
* of the stacking during the completion
|
|
* - the submission which requires queue lock may be done
|
|
* against this queue
|
|
*/
|
|
dm_complete_request(clone, error);
|
|
}
|
|
|
|
/*
|
|
* Return maximum size of I/O possible at the supplied sector up to the current
|
|
* target boundary.
|
|
*/
|
|
static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t target_offset = dm_target_offset(ti, sector);
|
|
|
|
return ti->len - target_offset;
|
|
}
|
|
|
|
static sector_t max_io_len(sector_t sector, struct dm_target *ti)
|
|
{
|
|
sector_t len = max_io_len_target_boundary(sector, ti);
|
|
sector_t offset, max_len;
|
|
|
|
/*
|
|
* Does the target need to split even further?
|
|
*/
|
|
if (ti->max_io_len) {
|
|
offset = dm_target_offset(ti, sector);
|
|
if (unlikely(ti->max_io_len & (ti->max_io_len - 1)))
|
|
max_len = sector_div(offset, ti->max_io_len);
|
|
else
|
|
max_len = offset & (ti->max_io_len - 1);
|
|
max_len = ti->max_io_len - max_len;
|
|
|
|
if (len > max_len)
|
|
len = max_len;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
|
|
{
|
|
if (len > UINT_MAX) {
|
|
DMERR("Specified maximum size of target IO (%llu) exceeds limit (%u)",
|
|
(unsigned long long)len, UINT_MAX);
|
|
ti->error = "Maximum size of target IO is too large";
|
|
return -EINVAL;
|
|
}
|
|
|
|
ti->max_io_len = (uint32_t) len;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_set_target_max_io_len);
|
|
|
|
static void __map_bio(struct dm_target_io *tio)
|
|
{
|
|
int r;
|
|
sector_t sector;
|
|
struct mapped_device *md;
|
|
struct bio *clone = &tio->clone;
|
|
struct dm_target *ti = tio->ti;
|
|
|
|
clone->bi_end_io = clone_endio;
|
|
clone->bi_private = tio;
|
|
|
|
/*
|
|
* Map the clone. If r == 0 we don't need to do
|
|
* anything, the target has assumed ownership of
|
|
* this io.
|
|
*/
|
|
atomic_inc(&tio->io->io_count);
|
|
sector = clone->bi_sector;
|
|
r = ti->type->map(ti, clone);
|
|
if (r == DM_MAPIO_REMAPPED) {
|
|
/* the bio has been remapped so dispatch it */
|
|
|
|
trace_block_bio_remap(bdev_get_queue(clone->bi_bdev), clone,
|
|
tio->io->bio->bi_bdev->bd_dev, sector);
|
|
|
|
generic_make_request(clone);
|
|
} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
|
|
/* error the io and bail out, or requeue it if needed */
|
|
md = tio->io->md;
|
|
dec_pending(tio->io, r);
|
|
free_tio(md, tio);
|
|
} else if (r) {
|
|
DMWARN("unimplemented target map return value: %d", r);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
struct clone_info {
|
|
struct mapped_device *md;
|
|
struct dm_table *map;
|
|
struct bio *bio;
|
|
struct dm_io *io;
|
|
sector_t sector;
|
|
sector_t sector_count;
|
|
unsigned short idx;
|
|
};
|
|
|
|
static void bio_setup_sector(struct bio *bio, sector_t sector, sector_t len)
|
|
{
|
|
bio->bi_sector = sector;
|
|
bio->bi_size = to_bytes(len);
|
|
}
|
|
|
|
static void bio_setup_bv(struct bio *bio, unsigned short idx, unsigned short bv_count)
|
|
{
|
|
bio->bi_idx = idx;
|
|
bio->bi_vcnt = idx + bv_count;
|
|
bio->bi_flags &= ~(1 << BIO_SEG_VALID);
|
|
}
|
|
|
|
static void clone_bio_integrity(struct bio *bio, struct bio *clone,
|
|
unsigned short idx, unsigned len, unsigned offset,
|
|
unsigned trim)
|
|
{
|
|
if (!bio_integrity(bio))
|
|
return;
|
|
|
|
bio_integrity_clone(clone, bio, GFP_NOIO);
|
|
|
|
if (trim)
|
|
bio_integrity_trim(clone, bio_sector_offset(bio, idx, offset), len);
|
|
}
|
|
|
|
/*
|
|
* Creates a little bio that just does part of a bvec.
|
|
*/
|
|
static void clone_split_bio(struct dm_target_io *tio, struct bio *bio,
|
|
sector_t sector, unsigned short idx,
|
|
unsigned offset, unsigned len)
|
|
{
|
|
struct bio *clone = &tio->clone;
|
|
struct bio_vec *bv = bio->bi_io_vec + idx;
|
|
|
|
*clone->bi_io_vec = *bv;
|
|
|
|
bio_setup_sector(clone, sector, len);
|
|
|
|
clone->bi_bdev = bio->bi_bdev;
|
|
clone->bi_rw = bio->bi_rw;
|
|
clone->bi_vcnt = 1;
|
|
clone->bi_io_vec->bv_offset = offset;
|
|
clone->bi_io_vec->bv_len = clone->bi_size;
|
|
clone->bi_flags |= 1 << BIO_CLONED;
|
|
|
|
clone_bio_integrity(bio, clone, idx, len, offset, 1);
|
|
}
|
|
|
|
/*
|
|
* Creates a bio that consists of range of complete bvecs.
|
|
*/
|
|
static void clone_bio(struct dm_target_io *tio, struct bio *bio,
|
|
sector_t sector, unsigned short idx,
|
|
unsigned short bv_count, unsigned len)
|
|
{
|
|
struct bio *clone = &tio->clone;
|
|
unsigned trim = 0;
|
|
|
|
__bio_clone(clone, bio);
|
|
bio_setup_sector(clone, sector, len);
|
|
bio_setup_bv(clone, idx, bv_count);
|
|
|
|
if (idx != bio->bi_idx || clone->bi_size < bio->bi_size)
|
|
trim = 1;
|
|
clone_bio_integrity(bio, clone, idx, len, 0, trim);
|
|
}
|
|
|
|
static struct dm_target_io *alloc_tio(struct clone_info *ci,
|
|
struct dm_target *ti, int nr_iovecs,
|
|
unsigned target_bio_nr)
|
|
{
|
|
struct dm_target_io *tio;
|
|
struct bio *clone;
|
|
|
|
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, ci->md->bs);
|
|
tio = container_of(clone, struct dm_target_io, clone);
|
|
|
|
tio->io = ci->io;
|
|
tio->ti = ti;
|
|
memset(&tio->info, 0, sizeof(tio->info));
|
|
tio->target_bio_nr = target_bio_nr;
|
|
|
|
return tio;
|
|
}
|
|
|
|
static void __clone_and_map_simple_bio(struct clone_info *ci,
|
|
struct dm_target *ti,
|
|
unsigned target_bio_nr, sector_t len)
|
|
{
|
|
struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs, target_bio_nr);
|
|
struct bio *clone = &tio->clone;
|
|
|
|
/*
|
|
* Discard requests require the bio's inline iovecs be initialized.
|
|
* ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush
|
|
* and discard, so no need for concern about wasted bvec allocations.
|
|
*/
|
|
__bio_clone(clone, ci->bio);
|
|
if (len)
|
|
bio_setup_sector(clone, ci->sector, len);
|
|
|
|
__map_bio(tio);
|
|
}
|
|
|
|
static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
|
|
unsigned num_bios, sector_t len)
|
|
{
|
|
unsigned target_bio_nr;
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
|
|
__clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
|
|
}
|
|
|
|
static int __send_empty_flush(struct clone_info *ci)
|
|
{
|
|
unsigned target_nr = 0;
|
|
struct dm_target *ti;
|
|
|
|
BUG_ON(bio_has_data(ci->bio));
|
|
while ((ti = dm_table_get_target(ci->map, target_nr++)))
|
|
__send_duplicate_bios(ci, ti, ti->num_flush_bios, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
|
|
sector_t sector, int nr_iovecs,
|
|
unsigned short idx, unsigned short bv_count,
|
|
unsigned offset, unsigned len,
|
|
unsigned split_bvec)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target_io *tio;
|
|
unsigned target_bio_nr;
|
|
unsigned num_target_bios = 1;
|
|
|
|
/*
|
|
* Does the target want to receive duplicate copies of the bio?
|
|
*/
|
|
if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
|
|
num_target_bios = ti->num_write_bios(ti, bio);
|
|
|
|
for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
|
|
tio = alloc_tio(ci, ti, nr_iovecs, target_bio_nr);
|
|
if (split_bvec)
|
|
clone_split_bio(tio, bio, sector, idx, offset, len);
|
|
else
|
|
clone_bio(tio, bio, sector, idx, bv_count, len);
|
|
__map_bio(tio);
|
|
}
|
|
}
|
|
|
|
typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
|
|
|
|
static unsigned get_num_discard_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_discard_bios;
|
|
}
|
|
|
|
static unsigned get_num_write_same_bios(struct dm_target *ti)
|
|
{
|
|
return ti->num_write_same_bios;
|
|
}
|
|
|
|
typedef bool (*is_split_required_fn)(struct dm_target *ti);
|
|
|
|
static bool is_split_required_for_discard(struct dm_target *ti)
|
|
{
|
|
return ti->split_discard_bios;
|
|
}
|
|
|
|
static int __send_changing_extent_only(struct clone_info *ci,
|
|
get_num_bios_fn get_num_bios,
|
|
is_split_required_fn is_split_required)
|
|
{
|
|
struct dm_target *ti;
|
|
sector_t len;
|
|
unsigned num_bios;
|
|
|
|
do {
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
/*
|
|
* Even though the device advertised support for this type of
|
|
* request, that does not mean every target supports it, and
|
|
* reconfiguration might also have changed that since the
|
|
* check was performed.
|
|
*/
|
|
num_bios = get_num_bios ? get_num_bios(ti) : 0;
|
|
if (!num_bios)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (is_split_required && !is_split_required(ti))
|
|
len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
|
|
else
|
|
len = min(ci->sector_count, max_io_len(ci->sector, ti));
|
|
|
|
__send_duplicate_bios(ci, ti, num_bios, len);
|
|
|
|
ci->sector += len;
|
|
} while (ci->sector_count -= len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __send_discard(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_discard_bios,
|
|
is_split_required_for_discard);
|
|
}
|
|
|
|
static int __send_write_same(struct clone_info *ci)
|
|
{
|
|
return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
|
|
}
|
|
|
|
/*
|
|
* Find maximum number of sectors / bvecs we can process with a single bio.
|
|
*/
|
|
static sector_t __len_within_target(struct clone_info *ci, sector_t max, int *idx)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
sector_t bv_len, total_len = 0;
|
|
|
|
for (*idx = ci->idx; max && (*idx < bio->bi_vcnt); (*idx)++) {
|
|
bv_len = to_sector(bio->bi_io_vec[*idx].bv_len);
|
|
|
|
if (bv_len > max)
|
|
break;
|
|
|
|
max -= bv_len;
|
|
total_len += bv_len;
|
|
}
|
|
|
|
return total_len;
|
|
}
|
|
|
|
static int __split_bvec_across_targets(struct clone_info *ci,
|
|
struct dm_target *ti, sector_t max)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct bio_vec *bv = bio->bi_io_vec + ci->idx;
|
|
sector_t remaining = to_sector(bv->bv_len);
|
|
unsigned offset = 0;
|
|
sector_t len;
|
|
|
|
do {
|
|
if (offset) {
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
max = max_io_len(ci->sector, ti);
|
|
}
|
|
|
|
len = min(remaining, max);
|
|
|
|
__clone_and_map_data_bio(ci, ti, ci->sector, 1, ci->idx, 0,
|
|
bv->bv_offset + offset, len, 1);
|
|
|
|
ci->sector += len;
|
|
ci->sector_count -= len;
|
|
offset += to_bytes(len);
|
|
} while (remaining -= len);
|
|
|
|
ci->idx++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Select the correct strategy for processing a non-flush bio.
|
|
*/
|
|
static int __split_and_process_non_flush(struct clone_info *ci)
|
|
{
|
|
struct bio *bio = ci->bio;
|
|
struct dm_target *ti;
|
|
sector_t len, max;
|
|
int idx;
|
|
|
|
if (unlikely(bio->bi_rw & REQ_DISCARD))
|
|
return __send_discard(ci);
|
|
else if (unlikely(bio->bi_rw & REQ_WRITE_SAME))
|
|
return __send_write_same(ci);
|
|
|
|
ti = dm_table_find_target(ci->map, ci->sector);
|
|
if (!dm_target_is_valid(ti))
|
|
return -EIO;
|
|
|
|
max = max_io_len(ci->sector, ti);
|
|
|
|
/*
|
|
* Optimise for the simple case where we can do all of
|
|
* the remaining io with a single clone.
|
|
*/
|
|
if (ci->sector_count <= max) {
|
|
__clone_and_map_data_bio(ci, ti, ci->sector, bio->bi_max_vecs,
|
|
ci->idx, bio->bi_vcnt - ci->idx, 0,
|
|
ci->sector_count, 0);
|
|
ci->sector_count = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* There are some bvecs that don't span targets.
|
|
* Do as many of these as possible.
|
|
*/
|
|
if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) {
|
|
len = __len_within_target(ci, max, &idx);
|
|
|
|
__clone_and_map_data_bio(ci, ti, ci->sector, bio->bi_max_vecs,
|
|
ci->idx, idx - ci->idx, 0, len, 0);
|
|
|
|
ci->sector += len;
|
|
ci->sector_count -= len;
|
|
ci->idx = idx;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Handle a bvec that must be split between two or more targets.
|
|
*/
|
|
return __split_bvec_across_targets(ci, ti, max);
|
|
}
|
|
|
|
/*
|
|
* Entry point to split a bio into clones and submit them to the targets.
|
|
*/
|
|
static void __split_and_process_bio(struct mapped_device *md,
|
|
struct dm_table *map, struct bio *bio)
|
|
{
|
|
struct clone_info ci;
|
|
int error = 0;
|
|
|
|
if (unlikely(!map)) {
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
|
|
ci.map = map;
|
|
ci.md = md;
|
|
ci.io = alloc_io(md);
|
|
ci.io->error = 0;
|
|
atomic_set(&ci.io->io_count, 1);
|
|
ci.io->bio = bio;
|
|
ci.io->md = md;
|
|
spin_lock_init(&ci.io->endio_lock);
|
|
ci.sector = bio->bi_sector;
|
|
ci.idx = bio->bi_idx;
|
|
|
|
start_io_acct(ci.io);
|
|
|
|
if (bio->bi_rw & REQ_FLUSH) {
|
|
ci.bio = &ci.md->flush_bio;
|
|
ci.sector_count = 0;
|
|
error = __send_empty_flush(&ci);
|
|
/* dec_pending submits any data associated with flush */
|
|
} else {
|
|
ci.bio = bio;
|
|
ci.sector_count = bio_sectors(bio);
|
|
while (ci.sector_count && !error)
|
|
error = __split_and_process_non_flush(&ci);
|
|
}
|
|
|
|
/* drop the extra reference count */
|
|
dec_pending(ci.io, error);
|
|
}
|
|
/*-----------------------------------------------------------------
|
|
* CRUD END
|
|
*---------------------------------------------------------------*/
|
|
|
|
static int dm_merge_bvec(struct request_queue *q,
|
|
struct bvec_merge_data *bvm,
|
|
struct bio_vec *biovec)
|
|
{
|
|
struct mapped_device *md = q->queuedata;
|
|
struct dm_table *map = dm_get_live_table_fast(md);
|
|
struct dm_target *ti;
|
|
sector_t max_sectors;
|
|
int max_size = 0;
|
|
|
|
if (unlikely(!map))
|
|
goto out;
|
|
|
|
ti = dm_table_find_target(map, bvm->bi_sector);
|
|
if (!dm_target_is_valid(ti))
|
|
goto out;
|
|
|
|
/*
|
|
* Find maximum amount of I/O that won't need splitting
|
|
*/
|
|
max_sectors = min(max_io_len(bvm->bi_sector, ti),
|
|
(sector_t) BIO_MAX_SECTORS);
|
|
max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
|
|
if (max_size < 0)
|
|
max_size = 0;
|
|
|
|
/*
|
|
* merge_bvec_fn() returns number of bytes
|
|
* it can accept at this offset
|
|
* max is precomputed maximal io size
|
|
*/
|
|
if (max_size && ti->type->merge)
|
|
max_size = ti->type->merge(ti, bvm, biovec, max_size);
|
|
/*
|
|
* If the target doesn't support merge method and some of the devices
|
|
* provided their merge_bvec method (we know this by looking at
|
|
* queue_max_hw_sectors), then we can't allow bios with multiple vector
|
|
* entries. So always set max_size to 0, and the code below allows
|
|
* just one page.
|
|
*/
|
|
else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
|
|
|
|
max_size = 0;
|
|
|
|
out:
|
|
dm_put_live_table_fast(md);
|
|
/*
|
|
* Always allow an entire first page
|
|
*/
|
|
if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
|
|
max_size = biovec->bv_len;
|
|
|
|
return max_size;
|
|
}
|
|
|
|
/*
|
|
* The request function that just remaps the bio built up by
|
|
* dm_merge_bvec.
|
|
*/
|
|
static void _dm_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
int rw = bio_data_dir(bio);
|
|
struct mapped_device *md = q->queuedata;
|
|
int cpu;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
cpu = part_stat_lock();
|
|
part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]);
|
|
part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
|
|
part_stat_unlock();
|
|
|
|
/* if we're suspended, we have to queue this io for later */
|
|
if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) {
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
if (bio_rw(bio) != READA)
|
|
queue_io(md, bio);
|
|
else
|
|
bio_io_error(bio);
|
|
return;
|
|
}
|
|
|
|
__split_and_process_bio(md, map, bio);
|
|
dm_put_live_table(md, srcu_idx);
|
|
return;
|
|
}
|
|
|
|
int dm_request_based(struct mapped_device *md)
|
|
{
|
|
return blk_queue_stackable(md->queue);
|
|
}
|
|
|
|
static void dm_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
struct mapped_device *md = q->queuedata;
|
|
|
|
if (dm_request_based(md))
|
|
blk_queue_bio(q, bio);
|
|
else
|
|
_dm_request(q, bio);
|
|
}
|
|
|
|
void dm_dispatch_request(struct request *rq)
|
|
{
|
|
int r;
|
|
|
|
if (blk_queue_io_stat(rq->q))
|
|
rq->cmd_flags |= REQ_IO_STAT;
|
|
|
|
rq->start_time = jiffies;
|
|
r = blk_insert_cloned_request(rq->q, rq);
|
|
if (r)
|
|
dm_complete_request(rq, r);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_dispatch_request);
|
|
|
|
static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
|
|
void *data)
|
|
{
|
|
struct dm_rq_target_io *tio = data;
|
|
struct dm_rq_clone_bio_info *info =
|
|
container_of(bio, struct dm_rq_clone_bio_info, clone);
|
|
|
|
info->orig = bio_orig;
|
|
info->tio = tio;
|
|
bio->bi_end_io = end_clone_bio;
|
|
bio->bi_private = info;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int setup_clone(struct request *clone, struct request *rq,
|
|
struct dm_rq_target_io *tio)
|
|
{
|
|
int r;
|
|
|
|
r = blk_rq_prep_clone(clone, rq, tio->md->bs, GFP_ATOMIC,
|
|
dm_rq_bio_constructor, tio);
|
|
if (r)
|
|
return r;
|
|
|
|
clone->cmd = rq->cmd;
|
|
clone->cmd_len = rq->cmd_len;
|
|
clone->sense = rq->sense;
|
|
clone->buffer = rq->buffer;
|
|
clone->end_io = end_clone_request;
|
|
clone->end_io_data = tio;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct request *clone_rq(struct request *rq, struct mapped_device *md,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct request *clone;
|
|
struct dm_rq_target_io *tio;
|
|
|
|
tio = alloc_rq_tio(md, gfp_mask);
|
|
if (!tio)
|
|
return NULL;
|
|
|
|
tio->md = md;
|
|
tio->ti = NULL;
|
|
tio->orig = rq;
|
|
tio->error = 0;
|
|
memset(&tio->info, 0, sizeof(tio->info));
|
|
|
|
clone = &tio->clone;
|
|
if (setup_clone(clone, rq, tio)) {
|
|
/* -ENOMEM */
|
|
free_rq_tio(tio);
|
|
return NULL;
|
|
}
|
|
|
|
return clone;
|
|
}
|
|
|
|
/*
|
|
* Called with the queue lock held.
|
|
*/
|
|
static int dm_prep_fn(struct request_queue *q, struct request *rq)
|
|
{
|
|
struct mapped_device *md = q->queuedata;
|
|
struct request *clone;
|
|
|
|
if (unlikely(rq->special)) {
|
|
DMWARN("Already has something in rq->special.");
|
|
return BLKPREP_KILL;
|
|
}
|
|
|
|
clone = clone_rq(rq, md, GFP_ATOMIC);
|
|
if (!clone)
|
|
return BLKPREP_DEFER;
|
|
|
|
rq->special = clone;
|
|
rq->cmd_flags |= REQ_DONTPREP;
|
|
|
|
return BLKPREP_OK;
|
|
}
|
|
|
|
/*
|
|
* Returns:
|
|
* 0 : the request has been processed (not requeued)
|
|
* !0 : the request has been requeued
|
|
*/
|
|
static int map_request(struct dm_target *ti, struct request *clone,
|
|
struct mapped_device *md)
|
|
{
|
|
int r, requeued = 0;
|
|
struct dm_rq_target_io *tio = clone->end_io_data;
|
|
|
|
tio->ti = ti;
|
|
r = ti->type->map_rq(ti, clone, &tio->info);
|
|
switch (r) {
|
|
case DM_MAPIO_SUBMITTED:
|
|
/* The target has taken the I/O to submit by itself later */
|
|
break;
|
|
case DM_MAPIO_REMAPPED:
|
|
/* The target has remapped the I/O so dispatch it */
|
|
trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
|
|
blk_rq_pos(tio->orig));
|
|
dm_dispatch_request(clone);
|
|
break;
|
|
case DM_MAPIO_REQUEUE:
|
|
/* The target wants to requeue the I/O */
|
|
dm_requeue_unmapped_request(clone);
|
|
requeued = 1;
|
|
break;
|
|
default:
|
|
if (r > 0) {
|
|
DMWARN("unimplemented target map return value: %d", r);
|
|
BUG();
|
|
}
|
|
|
|
/* The target wants to complete the I/O */
|
|
dm_kill_unmapped_request(clone, r);
|
|
break;
|
|
}
|
|
|
|
return requeued;
|
|
}
|
|
|
|
static struct request *dm_start_request(struct mapped_device *md, struct request *orig)
|
|
{
|
|
struct request *clone;
|
|
|
|
blk_start_request(orig);
|
|
clone = orig->special;
|
|
atomic_inc(&md->pending[rq_data_dir(clone)]);
|
|
|
|
/*
|
|
* Hold the md reference here for the in-flight I/O.
|
|
* We can't rely on the reference count by device opener,
|
|
* because the device may be closed during the request completion
|
|
* when all bios are completed.
|
|
* See the comment in rq_completed() too.
|
|
*/
|
|
dm_get(md);
|
|
|
|
return clone;
|
|
}
|
|
|
|
/*
|
|
* q->request_fn for request-based dm.
|
|
* Called with the queue lock held.
|
|
*/
|
|
static void dm_request_fn(struct request_queue *q)
|
|
{
|
|
struct mapped_device *md = q->queuedata;
|
|
int srcu_idx;
|
|
struct dm_table *map = dm_get_live_table(md, &srcu_idx);
|
|
struct dm_target *ti;
|
|
struct request *rq, *clone;
|
|
sector_t pos;
|
|
|
|
/*
|
|
* For suspend, check blk_queue_stopped() and increment
|
|
* ->pending within a single queue_lock not to increment the
|
|
* number of in-flight I/Os after the queue is stopped in
|
|
* dm_suspend().
|
|
*/
|
|
while (!blk_queue_stopped(q)) {
|
|
rq = blk_peek_request(q);
|
|
if (!rq)
|
|
goto delay_and_out;
|
|
|
|
/* always use block 0 to find the target for flushes for now */
|
|
pos = 0;
|
|
if (!(rq->cmd_flags & REQ_FLUSH))
|
|
pos = blk_rq_pos(rq);
|
|
|
|
ti = dm_table_find_target(map, pos);
|
|
if (!dm_target_is_valid(ti)) {
|
|
/*
|
|
* Must perform setup, that dm_done() requires,
|
|
* before calling dm_kill_unmapped_request
|
|
*/
|
|
DMERR_LIMIT("request attempted access beyond the end of device");
|
|
clone = dm_start_request(md, rq);
|
|
dm_kill_unmapped_request(clone, -EIO);
|
|
continue;
|
|
}
|
|
|
|
if (ti->type->busy && ti->type->busy(ti))
|
|
goto delay_and_out;
|
|
|
|
clone = dm_start_request(md, rq);
|
|
|
|
spin_unlock(q->queue_lock);
|
|
if (map_request(ti, clone, md))
|
|
goto requeued;
|
|
|
|
BUG_ON(!irqs_disabled());
|
|
spin_lock(q->queue_lock);
|
|
}
|
|
|
|
goto out;
|
|
|
|
requeued:
|
|
BUG_ON(!irqs_disabled());
|
|
spin_lock(q->queue_lock);
|
|
|
|
delay_and_out:
|
|
blk_delay_queue(q, HZ / 10);
|
|
out:
|
|
dm_put_live_table(md, srcu_idx);
|
|
}
|
|
|
|
int dm_underlying_device_busy(struct request_queue *q)
|
|
{
|
|
return blk_lld_busy(q);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_underlying_device_busy);
|
|
|
|
static int dm_lld_busy(struct request_queue *q)
|
|
{
|
|
int r;
|
|
struct mapped_device *md = q->queuedata;
|
|
struct dm_table *map = dm_get_live_table_fast(md);
|
|
|
|
if (!map || test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))
|
|
r = 1;
|
|
else
|
|
r = dm_table_any_busy_target(map);
|
|
|
|
dm_put_live_table_fast(md);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int dm_any_congested(void *congested_data, int bdi_bits)
|
|
{
|
|
int r = bdi_bits;
|
|
struct mapped_device *md = congested_data;
|
|
struct dm_table *map;
|
|
|
|
if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
map = dm_get_live_table_fast(md);
|
|
if (map) {
|
|
/*
|
|
* Request-based dm cares about only own queue for
|
|
* the query about congestion status of request_queue
|
|
*/
|
|
if (dm_request_based(md))
|
|
r = md->queue->backing_dev_info.state &
|
|
bdi_bits;
|
|
else
|
|
r = dm_table_any_congested(map, bdi_bits);
|
|
}
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* An IDR is used to keep track of allocated minor numbers.
|
|
*---------------------------------------------------------------*/
|
|
static void free_minor(int minor)
|
|
{
|
|
spin_lock(&_minor_lock);
|
|
idr_remove(&_minor_idr, minor);
|
|
spin_unlock(&_minor_lock);
|
|
}
|
|
|
|
/*
|
|
* See if the device with a specific minor # is free.
|
|
*/
|
|
static int specific_minor(int minor)
|
|
{
|
|
int r;
|
|
|
|
if (minor >= (1 << MINORBITS))
|
|
return -EINVAL;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, minor, minor + 1, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r == -ENOSPC ? -EBUSY : r;
|
|
return 0;
|
|
}
|
|
|
|
static int next_free_minor(int *minor)
|
|
{
|
|
int r;
|
|
|
|
idr_preload(GFP_KERNEL);
|
|
spin_lock(&_minor_lock);
|
|
|
|
r = idr_alloc(&_minor_idr, MINOR_ALLOCED, 0, 1 << MINORBITS, GFP_NOWAIT);
|
|
|
|
spin_unlock(&_minor_lock);
|
|
idr_preload_end();
|
|
if (r < 0)
|
|
return r;
|
|
*minor = r;
|
|
return 0;
|
|
}
|
|
|
|
static const struct block_device_operations dm_blk_dops;
|
|
|
|
static void dm_wq_work(struct work_struct *work);
|
|
|
|
static void dm_init_md_queue(struct mapped_device *md)
|
|
{
|
|
/*
|
|
* Request-based dm devices cannot be stacked on top of bio-based dm
|
|
* devices. The type of this dm device has not been decided yet.
|
|
* The type is decided at the first table loading time.
|
|
* To prevent problematic device stacking, clear the queue flag
|
|
* for request stacking support until then.
|
|
*
|
|
* This queue is new, so no concurrency on the queue_flags.
|
|
*/
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
|
|
|
|
md->queue->queuedata = md;
|
|
md->queue->backing_dev_info.congested_fn = dm_any_congested;
|
|
md->queue->backing_dev_info.congested_data = md;
|
|
blk_queue_make_request(md->queue, dm_request);
|
|
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
|
|
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
|
|
}
|
|
|
|
/*
|
|
* Allocate and initialise a blank device with a given minor.
|
|
*/
|
|
static struct mapped_device *alloc_dev(int minor)
|
|
{
|
|
int r;
|
|
struct mapped_device *md = kzalloc(sizeof(*md), GFP_KERNEL);
|
|
void *old_md;
|
|
|
|
if (!md) {
|
|
DMWARN("unable to allocate device, out of memory.");
|
|
return NULL;
|
|
}
|
|
|
|
if (!try_module_get(THIS_MODULE))
|
|
goto bad_module_get;
|
|
|
|
/* get a minor number for the dev */
|
|
if (minor == DM_ANY_MINOR)
|
|
r = next_free_minor(&minor);
|
|
else
|
|
r = specific_minor(minor);
|
|
if (r < 0)
|
|
goto bad_minor;
|
|
|
|
r = init_srcu_struct(&md->io_barrier);
|
|
if (r < 0)
|
|
goto bad_io_barrier;
|
|
|
|
md->type = DM_TYPE_NONE;
|
|
mutex_init(&md->suspend_lock);
|
|
mutex_init(&md->type_lock);
|
|
spin_lock_init(&md->deferred_lock);
|
|
atomic_set(&md->holders, 1);
|
|
atomic_set(&md->open_count, 0);
|
|
atomic_set(&md->event_nr, 0);
|
|
atomic_set(&md->uevent_seq, 0);
|
|
INIT_LIST_HEAD(&md->uevent_list);
|
|
spin_lock_init(&md->uevent_lock);
|
|
|
|
md->queue = blk_alloc_queue(GFP_KERNEL);
|
|
if (!md->queue)
|
|
goto bad_queue;
|
|
|
|
dm_init_md_queue(md);
|
|
|
|
md->disk = alloc_disk(1);
|
|
if (!md->disk)
|
|
goto bad_disk;
|
|
|
|
atomic_set(&md->pending[0], 0);
|
|
atomic_set(&md->pending[1], 0);
|
|
init_waitqueue_head(&md->wait);
|
|
INIT_WORK(&md->work, dm_wq_work);
|
|
init_waitqueue_head(&md->eventq);
|
|
|
|
md->disk->major = _major;
|
|
md->disk->first_minor = minor;
|
|
md->disk->fops = &dm_blk_dops;
|
|
md->disk->queue = md->queue;
|
|
md->disk->private_data = md;
|
|
sprintf(md->disk->disk_name, "dm-%d", minor);
|
|
add_disk(md->disk);
|
|
format_dev_t(md->name, MKDEV(_major, minor));
|
|
|
|
md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
|
|
if (!md->wq)
|
|
goto bad_thread;
|
|
|
|
md->bdev = bdget_disk(md->disk, 0);
|
|
if (!md->bdev)
|
|
goto bad_bdev;
|
|
|
|
bio_init(&md->flush_bio);
|
|
md->flush_bio.bi_bdev = md->bdev;
|
|
md->flush_bio.bi_rw = WRITE_FLUSH;
|
|
|
|
dm_stats_init(&md->stats);
|
|
|
|
/* Populate the mapping, nobody knows we exist yet */
|
|
spin_lock(&_minor_lock);
|
|
old_md = idr_replace(&_minor_idr, md, minor);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
BUG_ON(old_md != MINOR_ALLOCED);
|
|
|
|
return md;
|
|
|
|
bad_bdev:
|
|
destroy_workqueue(md->wq);
|
|
bad_thread:
|
|
del_gendisk(md->disk);
|
|
put_disk(md->disk);
|
|
bad_disk:
|
|
blk_cleanup_queue(md->queue);
|
|
bad_queue:
|
|
cleanup_srcu_struct(&md->io_barrier);
|
|
bad_io_barrier:
|
|
free_minor(minor);
|
|
bad_minor:
|
|
module_put(THIS_MODULE);
|
|
bad_module_get:
|
|
kfree(md);
|
|
return NULL;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md);
|
|
|
|
static void free_dev(struct mapped_device *md)
|
|
{
|
|
int minor = MINOR(disk_devt(md->disk));
|
|
|
|
unlock_fs(md);
|
|
bdput(md->bdev);
|
|
destroy_workqueue(md->wq);
|
|
if (md->io_pool)
|
|
mempool_destroy(md->io_pool);
|
|
if (md->bs)
|
|
bioset_free(md->bs);
|
|
blk_integrity_unregister(md->disk);
|
|
del_gendisk(md->disk);
|
|
cleanup_srcu_struct(&md->io_barrier);
|
|
free_minor(minor);
|
|
|
|
spin_lock(&_minor_lock);
|
|
md->disk->private_data = NULL;
|
|
spin_unlock(&_minor_lock);
|
|
|
|
put_disk(md->disk);
|
|
blk_cleanup_queue(md->queue);
|
|
dm_stats_cleanup(&md->stats);
|
|
module_put(THIS_MODULE);
|
|
kfree(md);
|
|
}
|
|
|
|
static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
|
|
{
|
|
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
|
|
|
|
if (md->io_pool && md->bs) {
|
|
/* The md already has necessary mempools. */
|
|
if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) {
|
|
/*
|
|
* Reload bioset because front_pad may have changed
|
|
* because a different table was loaded.
|
|
*/
|
|
bioset_free(md->bs);
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
} else if (dm_table_get_type(t) == DM_TYPE_REQUEST_BASED) {
|
|
/*
|
|
* There's no need to reload with request-based dm
|
|
* because the size of front_pad doesn't change.
|
|
* Note for future: If you are to reload bioset,
|
|
* prep-ed requests in the queue may refer
|
|
* to bio from the old bioset, so you must walk
|
|
* through the queue to unprep.
|
|
*/
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
BUG_ON(!p || md->io_pool || md->bs);
|
|
|
|
md->io_pool = p->io_pool;
|
|
p->io_pool = NULL;
|
|
md->bs = p->bs;
|
|
p->bs = NULL;
|
|
|
|
out:
|
|
/* mempool bind completed, now no need any mempools in the table */
|
|
dm_table_free_md_mempools(t);
|
|
}
|
|
|
|
/*
|
|
* Bind a table to the device.
|
|
*/
|
|
static void event_callback(void *context)
|
|
{
|
|
unsigned long flags;
|
|
LIST_HEAD(uevents);
|
|
struct mapped_device *md = (struct mapped_device *) context;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_splice_init(&md->uevent_list, &uevents);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
|
|
dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
|
|
|
|
atomic_inc(&md->event_nr);
|
|
wake_up(&md->eventq);
|
|
}
|
|
|
|
/*
|
|
* Protected by md->suspend_lock obtained by dm_swap_table().
|
|
*/
|
|
static void __set_size(struct mapped_device *md, sector_t size)
|
|
{
|
|
set_capacity(md->disk, size);
|
|
|
|
i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
|
|
}
|
|
|
|
/*
|
|
* Return 1 if the queue has a compulsory merge_bvec_fn function.
|
|
*
|
|
* If this function returns 0, then the device is either a non-dm
|
|
* device without a merge_bvec_fn, or it is a dm device that is
|
|
* able to split any bios it receives that are too big.
|
|
*/
|
|
int dm_queue_merge_is_compulsory(struct request_queue *q)
|
|
{
|
|
struct mapped_device *dev_md;
|
|
|
|
if (!q->merge_bvec_fn)
|
|
return 0;
|
|
|
|
if (q->make_request_fn == dm_request) {
|
|
dev_md = q->queuedata;
|
|
if (test_bit(DMF_MERGE_IS_OPTIONAL, &dev_md->flags))
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int dm_device_merge_is_compulsory(struct dm_target *ti,
|
|
struct dm_dev *dev, sector_t start,
|
|
sector_t len, void *data)
|
|
{
|
|
struct block_device *bdev = dev->bdev;
|
|
struct request_queue *q = bdev_get_queue(bdev);
|
|
|
|
return dm_queue_merge_is_compulsory(q);
|
|
}
|
|
|
|
/*
|
|
* Return 1 if it is acceptable to ignore merge_bvec_fn based
|
|
* on the properties of the underlying devices.
|
|
*/
|
|
static int dm_table_merge_is_optional(struct dm_table *table)
|
|
{
|
|
unsigned i = 0;
|
|
struct dm_target *ti;
|
|
|
|
while (i < dm_table_get_num_targets(table)) {
|
|
ti = dm_table_get_target(table, i++);
|
|
|
|
if (ti->type->iterate_devices &&
|
|
ti->type->iterate_devices(ti, dm_device_merge_is_compulsory, NULL))
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Returns old map, which caller must destroy.
|
|
*/
|
|
static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
|
|
struct queue_limits *limits)
|
|
{
|
|
struct dm_table *old_map;
|
|
struct request_queue *q = md->queue;
|
|
sector_t size;
|
|
int merge_is_optional;
|
|
|
|
size = dm_table_get_size(t);
|
|
|
|
/*
|
|
* Wipe any geometry if the size of the table changed.
|
|
*/
|
|
if (size != dm_get_size(md))
|
|
memset(&md->geometry, 0, sizeof(md->geometry));
|
|
|
|
__set_size(md, size);
|
|
|
|
dm_table_event_callback(t, event_callback, md);
|
|
|
|
/*
|
|
* The queue hasn't been stopped yet, if the old table type wasn't
|
|
* for request-based during suspension. So stop it to prevent
|
|
* I/O mapping before resume.
|
|
* This must be done before setting the queue restrictions,
|
|
* because request-based dm may be run just after the setting.
|
|
*/
|
|
if (dm_table_request_based(t) && !blk_queue_stopped(q))
|
|
stop_queue(q);
|
|
|
|
__bind_mempools(md, t);
|
|
|
|
merge_is_optional = dm_table_merge_is_optional(t);
|
|
|
|
old_map = md->map;
|
|
rcu_assign_pointer(md->map, t);
|
|
md->immutable_target_type = dm_table_get_immutable_target_type(t);
|
|
|
|
dm_table_set_restrictions(t, q, limits);
|
|
if (merge_is_optional)
|
|
set_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
|
|
else
|
|
clear_bit(DMF_MERGE_IS_OPTIONAL, &md->flags);
|
|
dm_sync_table(md);
|
|
|
|
return old_map;
|
|
}
|
|
|
|
/*
|
|
* Returns unbound table for the caller to free.
|
|
*/
|
|
static struct dm_table *__unbind(struct mapped_device *md)
|
|
{
|
|
struct dm_table *map = md->map;
|
|
|
|
if (!map)
|
|
return NULL;
|
|
|
|
dm_table_event_callback(map, NULL, NULL);
|
|
rcu_assign_pointer(md->map, NULL);
|
|
dm_sync_table(md);
|
|
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Constructor for a new device.
|
|
*/
|
|
int dm_create(int minor, struct mapped_device **result)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = alloc_dev(minor);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
dm_sysfs_init(md);
|
|
|
|
*result = md;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Functions to manage md->type.
|
|
* All are required to hold md->type_lock.
|
|
*/
|
|
void dm_lock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->type_lock);
|
|
}
|
|
|
|
void dm_unlock_md_type(struct mapped_device *md)
|
|
{
|
|
mutex_unlock(&md->type_lock);
|
|
}
|
|
|
|
void dm_set_md_type(struct mapped_device *md, unsigned type)
|
|
{
|
|
BUG_ON(!mutex_is_locked(&md->type_lock));
|
|
md->type = type;
|
|
}
|
|
|
|
unsigned dm_get_md_type(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!mutex_is_locked(&md->type_lock));
|
|
return md->type;
|
|
}
|
|
|
|
struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
|
|
{
|
|
return md->immutable_target_type;
|
|
}
|
|
|
|
/*
|
|
* The queue_limits are only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
|
|
{
|
|
BUG_ON(!atomic_read(&md->holders));
|
|
return &md->queue->limits;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_queue_limits);
|
|
|
|
/*
|
|
* Fully initialize a request-based queue (->elevator, ->request_fn, etc).
|
|
*/
|
|
static int dm_init_request_based_queue(struct mapped_device *md)
|
|
{
|
|
struct request_queue *q = NULL;
|
|
|
|
if (md->queue->elevator)
|
|
return 1;
|
|
|
|
/* Fully initialize the queue */
|
|
q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
|
|
if (!q)
|
|
return 0;
|
|
|
|
md->queue = q;
|
|
dm_init_md_queue(md);
|
|
blk_queue_softirq_done(md->queue, dm_softirq_done);
|
|
blk_queue_prep_rq(md->queue, dm_prep_fn);
|
|
blk_queue_lld_busy(md->queue, dm_lld_busy);
|
|
|
|
elv_register_queue(md->queue);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Setup the DM device's queue based on md's type
|
|
*/
|
|
int dm_setup_md_queue(struct mapped_device *md)
|
|
{
|
|
if ((dm_get_md_type(md) == DM_TYPE_REQUEST_BASED) &&
|
|
!dm_init_request_based_queue(md)) {
|
|
DMWARN("Cannot initialize queue for request-based mapped device");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct mapped_device *dm_find_md(dev_t dev)
|
|
{
|
|
struct mapped_device *md;
|
|
unsigned minor = MINOR(dev);
|
|
|
|
if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
|
|
return NULL;
|
|
|
|
spin_lock(&_minor_lock);
|
|
|
|
md = idr_find(&_minor_idr, minor);
|
|
if (md && (md == MINOR_ALLOCED ||
|
|
(MINOR(disk_devt(dm_disk(md))) != minor) ||
|
|
dm_deleting_md(md) ||
|
|
test_bit(DMF_FREEING, &md->flags))) {
|
|
md = NULL;
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
spin_unlock(&_minor_lock);
|
|
|
|
return md;
|
|
}
|
|
|
|
struct mapped_device *dm_get_md(dev_t dev)
|
|
{
|
|
struct mapped_device *md = dm_find_md(dev);
|
|
|
|
if (md)
|
|
dm_get(md);
|
|
|
|
return md;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_get_md);
|
|
|
|
void *dm_get_mdptr(struct mapped_device *md)
|
|
{
|
|
return md->interface_ptr;
|
|
}
|
|
|
|
void dm_set_mdptr(struct mapped_device *md, void *ptr)
|
|
{
|
|
md->interface_ptr = ptr;
|
|
}
|
|
|
|
void dm_get(struct mapped_device *md)
|
|
{
|
|
atomic_inc(&md->holders);
|
|
BUG_ON(test_bit(DMF_FREEING, &md->flags));
|
|
}
|
|
|
|
const char *dm_device_name(struct mapped_device *md)
|
|
{
|
|
return md->name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_device_name);
|
|
|
|
static void __dm_destroy(struct mapped_device *md, bool wait)
|
|
{
|
|
struct dm_table *map;
|
|
int srcu_idx;
|
|
|
|
might_sleep();
|
|
|
|
spin_lock(&_minor_lock);
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
idr_replace(&_minor_idr, MINOR_ALLOCED, MINOR(disk_devt(dm_disk(md))));
|
|
set_bit(DMF_FREEING, &md->flags);
|
|
spin_unlock(&_minor_lock);
|
|
|
|
if (!dm_suspended_md(md)) {
|
|
dm_table_presuspend_targets(map);
|
|
dm_table_postsuspend_targets(map);
|
|
}
|
|
|
|
/* dm_put_live_table must be before msleep, otherwise deadlock is possible */
|
|
dm_put_live_table(md, srcu_idx);
|
|
|
|
/*
|
|
* Rare, but there may be I/O requests still going to complete,
|
|
* for example. Wait for all references to disappear.
|
|
* No one should increment the reference count of the mapped_device,
|
|
* after the mapped_device state becomes DMF_FREEING.
|
|
*/
|
|
if (wait)
|
|
while (atomic_read(&md->holders))
|
|
msleep(1);
|
|
else if (atomic_read(&md->holders))
|
|
DMWARN("%s: Forcibly removing mapped_device still in use! (%d users)",
|
|
dm_device_name(md), atomic_read(&md->holders));
|
|
|
|
dm_sysfs_exit(md);
|
|
dm_table_destroy(__unbind(md));
|
|
free_dev(md);
|
|
}
|
|
|
|
void dm_destroy(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, true);
|
|
}
|
|
|
|
void dm_destroy_immediate(struct mapped_device *md)
|
|
{
|
|
__dm_destroy(md, false);
|
|
}
|
|
|
|
void dm_put(struct mapped_device *md)
|
|
{
|
|
atomic_dec(&md->holders);
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_put);
|
|
|
|
static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
|
|
{
|
|
int r = 0;
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
add_wait_queue(&md->wait, &wait);
|
|
|
|
while (1) {
|
|
set_current_state(interruptible);
|
|
|
|
if (!md_in_flight(md))
|
|
break;
|
|
|
|
if (interruptible == TASK_INTERRUPTIBLE &&
|
|
signal_pending(current)) {
|
|
r = -EINTR;
|
|
break;
|
|
}
|
|
|
|
io_schedule();
|
|
}
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
remove_wait_queue(&md->wait, &wait);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Process the deferred bios
|
|
*/
|
|
static void dm_wq_work(struct work_struct *work)
|
|
{
|
|
struct mapped_device *md = container_of(work, struct mapped_device,
|
|
work);
|
|
struct bio *c;
|
|
int srcu_idx;
|
|
struct dm_table *map;
|
|
|
|
map = dm_get_live_table(md, &srcu_idx);
|
|
|
|
while (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
|
|
spin_lock_irq(&md->deferred_lock);
|
|
c = bio_list_pop(&md->deferred);
|
|
spin_unlock_irq(&md->deferred_lock);
|
|
|
|
if (!c)
|
|
break;
|
|
|
|
if (dm_request_based(md))
|
|
generic_make_request(c);
|
|
else
|
|
__split_and_process_bio(md, map, c);
|
|
}
|
|
|
|
dm_put_live_table(md, srcu_idx);
|
|
}
|
|
|
|
static void dm_queue_flush(struct mapped_device *md)
|
|
{
|
|
clear_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
smp_mb__after_clear_bit();
|
|
queue_work(md->wq, &md->work);
|
|
}
|
|
|
|
/*
|
|
* Swap in a new table, returning the old one for the caller to destroy.
|
|
*/
|
|
struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
|
|
{
|
|
struct dm_table *live_map = NULL, *map = ERR_PTR(-EINVAL);
|
|
struct queue_limits limits;
|
|
int r;
|
|
|
|
mutex_lock(&md->suspend_lock);
|
|
|
|
/* device must be suspended */
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
/*
|
|
* If the new table has no data devices, retain the existing limits.
|
|
* This helps multipath with queue_if_no_path if all paths disappear,
|
|
* then new I/O is queued based on these limits, and then some paths
|
|
* reappear.
|
|
*/
|
|
if (dm_table_has_no_data_devices(table)) {
|
|
live_map = dm_get_live_table_fast(md);
|
|
if (live_map)
|
|
limits = md->queue->limits;
|
|
dm_put_live_table_fast(md);
|
|
}
|
|
|
|
if (!live_map) {
|
|
r = dm_calculate_queue_limits(table, &limits);
|
|
if (r) {
|
|
map = ERR_PTR(r);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
map = __bind(md, table, &limits);
|
|
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return map;
|
|
}
|
|
|
|
/*
|
|
* Functions to lock and unlock any filesystem running on the
|
|
* device.
|
|
*/
|
|
static int lock_fs(struct mapped_device *md)
|
|
{
|
|
int r;
|
|
|
|
WARN_ON(md->frozen_sb);
|
|
|
|
md->frozen_sb = freeze_bdev(md->bdev);
|
|
if (IS_ERR(md->frozen_sb)) {
|
|
r = PTR_ERR(md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
return r;
|
|
}
|
|
|
|
set_bit(DMF_FROZEN, &md->flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void unlock_fs(struct mapped_device *md)
|
|
{
|
|
if (!test_bit(DMF_FROZEN, &md->flags))
|
|
return;
|
|
|
|
thaw_bdev(md->bdev, md->frozen_sb);
|
|
md->frozen_sb = NULL;
|
|
clear_bit(DMF_FROZEN, &md->flags);
|
|
}
|
|
|
|
/*
|
|
* We need to be able to change a mapping table under a mounted
|
|
* filesystem. For example we might want to move some data in
|
|
* the background. Before the table can be swapped with
|
|
* dm_bind_table, dm_suspend must be called to flush any in
|
|
* flight bios and ensure that any further io gets deferred.
|
|
*/
|
|
/*
|
|
* Suspend mechanism in request-based dm.
|
|
*
|
|
* 1. Flush all I/Os by lock_fs() if needed.
|
|
* 2. Stop dispatching any I/O by stopping the request_queue.
|
|
* 3. Wait for all in-flight I/Os to be completed or requeued.
|
|
*
|
|
* To abort suspend, start the request_queue.
|
|
*/
|
|
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
|
|
{
|
|
struct dm_table *map = NULL;
|
|
int r = 0;
|
|
int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
|
|
int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
|
|
|
|
mutex_lock(&md->suspend_lock);
|
|
|
|
if (dm_suspended_md(md)) {
|
|
r = -EINVAL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
map = md->map;
|
|
|
|
/*
|
|
* DMF_NOFLUSH_SUSPENDING must be set before presuspend.
|
|
* This flag is cleared before dm_suspend returns.
|
|
*/
|
|
if (noflush)
|
|
set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
|
|
/* This does not get reverted if there's an error later. */
|
|
dm_table_presuspend_targets(map);
|
|
|
|
/*
|
|
* Flush I/O to the device.
|
|
* Any I/O submitted after lock_fs() may not be flushed.
|
|
* noflush takes precedence over do_lockfs.
|
|
* (lock_fs() flushes I/Os and waits for them to complete.)
|
|
*/
|
|
if (!noflush && do_lockfs) {
|
|
r = lock_fs(md);
|
|
if (r)
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Here we must make sure that no processes are submitting requests
|
|
* to target drivers i.e. no one may be executing
|
|
* __split_and_process_bio. This is called from dm_request and
|
|
* dm_wq_work.
|
|
*
|
|
* To get all processes out of __split_and_process_bio in dm_request,
|
|
* we take the write lock. To prevent any process from reentering
|
|
* __split_and_process_bio from dm_request and quiesce the thread
|
|
* (dm_wq_work), we set BMF_BLOCK_IO_FOR_SUSPEND and call
|
|
* flush_workqueue(md->wq).
|
|
*/
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/*
|
|
* Stop md->queue before flushing md->wq in case request-based
|
|
* dm defers requests to md->wq from md->queue.
|
|
*/
|
|
if (dm_request_based(md))
|
|
stop_queue(md->queue);
|
|
|
|
flush_workqueue(md->wq);
|
|
|
|
/*
|
|
* At this point no more requests are entering target request routines.
|
|
* We call dm_wait_for_completion to wait for all existing requests
|
|
* to finish.
|
|
*/
|
|
r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE);
|
|
|
|
if (noflush)
|
|
clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
|
|
synchronize_srcu(&md->io_barrier);
|
|
|
|
/* were we interrupted ? */
|
|
if (r < 0) {
|
|
dm_queue_flush(md);
|
|
|
|
if (dm_request_based(md))
|
|
start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
goto out_unlock; /* pushback list is already flushed, so skip flush */
|
|
}
|
|
|
|
/*
|
|
* If dm_wait_for_completion returned 0, the device is completely
|
|
* quiescent now. There is no request-processing activity. All new
|
|
* requests are being added to md->deferred list.
|
|
*/
|
|
|
|
set_bit(DMF_SUSPENDED, &md->flags);
|
|
|
|
dm_table_postsuspend_targets(map);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&md->suspend_lock);
|
|
return r;
|
|
}
|
|
|
|
int dm_resume(struct mapped_device *md)
|
|
{
|
|
int r = -EINVAL;
|
|
struct dm_table *map = NULL;
|
|
|
|
mutex_lock(&md->suspend_lock);
|
|
if (!dm_suspended_md(md))
|
|
goto out;
|
|
|
|
map = md->map;
|
|
if (!map || !dm_table_get_size(map))
|
|
goto out;
|
|
|
|
r = dm_table_resume_targets(map);
|
|
if (r)
|
|
goto out;
|
|
|
|
dm_queue_flush(md);
|
|
|
|
/*
|
|
* Flushing deferred I/Os must be done after targets are resumed
|
|
* so that mapping of targets can work correctly.
|
|
* Request-based dm is queueing the deferred I/Os in its request_queue.
|
|
*/
|
|
if (dm_request_based(md))
|
|
start_queue(md->queue);
|
|
|
|
unlock_fs(md);
|
|
|
|
clear_bit(DMF_SUSPENDED, &md->flags);
|
|
|
|
r = 0;
|
|
out:
|
|
mutex_unlock(&md->suspend_lock);
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Internal suspend/resume works like userspace-driven suspend. It waits
|
|
* until all bios finish and prevents issuing new bios to the target drivers.
|
|
* It may be used only from the kernel.
|
|
*
|
|
* Internal suspend holds md->suspend_lock, which prevents interaction with
|
|
* userspace-driven suspend.
|
|
*/
|
|
|
|
void dm_internal_suspend(struct mapped_device *md)
|
|
{
|
|
mutex_lock(&md->suspend_lock);
|
|
if (dm_suspended_md(md))
|
|
return;
|
|
|
|
set_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags);
|
|
synchronize_srcu(&md->io_barrier);
|
|
flush_workqueue(md->wq);
|
|
dm_wait_for_completion(md, TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
void dm_internal_resume(struct mapped_device *md)
|
|
{
|
|
if (dm_suspended_md(md))
|
|
goto done;
|
|
|
|
dm_queue_flush(md);
|
|
|
|
done:
|
|
mutex_unlock(&md->suspend_lock);
|
|
}
|
|
|
|
/*-----------------------------------------------------------------
|
|
* Event notification.
|
|
*---------------------------------------------------------------*/
|
|
int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
|
|
unsigned cookie)
|
|
{
|
|
char udev_cookie[DM_COOKIE_LENGTH];
|
|
char *envp[] = { udev_cookie, NULL };
|
|
|
|
if (!cookie)
|
|
return kobject_uevent(&disk_to_dev(md->disk)->kobj, action);
|
|
else {
|
|
snprintf(udev_cookie, DM_COOKIE_LENGTH, "%s=%u",
|
|
DM_COOKIE_ENV_VAR_NAME, cookie);
|
|
return kobject_uevent_env(&disk_to_dev(md->disk)->kobj,
|
|
action, envp);
|
|
}
|
|
}
|
|
|
|
uint32_t dm_next_uevent_seq(struct mapped_device *md)
|
|
{
|
|
return atomic_add_return(1, &md->uevent_seq);
|
|
}
|
|
|
|
uint32_t dm_get_event_nr(struct mapped_device *md)
|
|
{
|
|
return atomic_read(&md->event_nr);
|
|
}
|
|
|
|
int dm_wait_event(struct mapped_device *md, int event_nr)
|
|
{
|
|
return wait_event_interruptible(md->eventq,
|
|
(event_nr != atomic_read(&md->event_nr)));
|
|
}
|
|
|
|
void dm_uevent_add(struct mapped_device *md, struct list_head *elist)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&md->uevent_lock, flags);
|
|
list_add(elist, &md->uevent_list);
|
|
spin_unlock_irqrestore(&md->uevent_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* The gendisk is only valid as long as you have a reference
|
|
* count on 'md'.
|
|
*/
|
|
struct gendisk *dm_disk(struct mapped_device *md)
|
|
{
|
|
return md->disk;
|
|
}
|
|
|
|
struct kobject *dm_kobject(struct mapped_device *md)
|
|
{
|
|
return &md->kobj;
|
|
}
|
|
|
|
/*
|
|
* struct mapped_device should not be exported outside of dm.c
|
|
* so use this check to verify that kobj is part of md structure
|
|
*/
|
|
struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
|
|
{
|
|
struct mapped_device *md;
|
|
|
|
md = container_of(kobj, struct mapped_device, kobj);
|
|
if (&md->kobj != kobj)
|
|
return NULL;
|
|
|
|
if (test_bit(DMF_FREEING, &md->flags) ||
|
|
dm_deleting_md(md))
|
|
return NULL;
|
|
|
|
dm_get(md);
|
|
return md;
|
|
}
|
|
|
|
int dm_suspended_md(struct mapped_device *md)
|
|
{
|
|
return test_bit(DMF_SUSPENDED, &md->flags);
|
|
}
|
|
|
|
int dm_suspended(struct dm_target *ti)
|
|
{
|
|
return dm_suspended_md(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_suspended);
|
|
|
|
int dm_noflush_suspending(struct dm_target *ti)
|
|
{
|
|
return __noflush_suspending(dm_table_get_md(ti->table));
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_noflush_suspending);
|
|
|
|
struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size)
|
|
{
|
|
struct dm_md_mempools *pools = kzalloc(sizeof(*pools), GFP_KERNEL);
|
|
struct kmem_cache *cachep;
|
|
unsigned int pool_size;
|
|
unsigned int front_pad;
|
|
|
|
if (!pools)
|
|
return NULL;
|
|
|
|
if (type == DM_TYPE_BIO_BASED) {
|
|
cachep = _io_cache;
|
|
pool_size = dm_get_reserved_bio_based_ios();
|
|
front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
|
|
} else if (type == DM_TYPE_REQUEST_BASED) {
|
|
cachep = _rq_tio_cache;
|
|
pool_size = dm_get_reserved_rq_based_ios();
|
|
front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
|
|
/* per_bio_data_size is not used. See __bind_mempools(). */
|
|
WARN_ON(per_bio_data_size != 0);
|
|
} else
|
|
goto out;
|
|
|
|
pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
|
|
if (!pools->io_pool)
|
|
goto out;
|
|
|
|
pools->bs = bioset_create(pool_size, front_pad);
|
|
if (!pools->bs)
|
|
goto out;
|
|
|
|
if (integrity && bioset_integrity_create(pools->bs, pool_size))
|
|
goto out;
|
|
|
|
return pools;
|
|
|
|
out:
|
|
dm_free_md_mempools(pools);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void dm_free_md_mempools(struct dm_md_mempools *pools)
|
|
{
|
|
if (!pools)
|
|
return;
|
|
|
|
if (pools->io_pool)
|
|
mempool_destroy(pools->io_pool);
|
|
|
|
if (pools->bs)
|
|
bioset_free(pools->bs);
|
|
|
|
kfree(pools);
|
|
}
|
|
|
|
static const struct block_device_operations dm_blk_dops = {
|
|
.open = dm_blk_open,
|
|
.release = dm_blk_close,
|
|
.ioctl = dm_blk_ioctl,
|
|
.getgeo = dm_blk_getgeo,
|
|
.owner = THIS_MODULE
|
|
};
|
|
|
|
EXPORT_SYMBOL(dm_get_mapinfo);
|
|
|
|
/*
|
|
* module hooks
|
|
*/
|
|
module_init(dm_init);
|
|
module_exit(dm_exit);
|
|
|
|
module_param(major, uint, 0);
|
|
MODULE_PARM_DESC(major, "The major number of the device mapper");
|
|
|
|
module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
|
|
|
|
module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools");
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " driver");
|
|
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|