Revision 311f71281ff4b24f86a39c60c959f485c68a6d36 authored by Linus Torvalds on 16 May 2019, 22:55:48 UTC, committed by Linus Torvalds on 16 May 2019, 22:55:48 UTC
Pull device mapper updates from Mike Snitzer: - Improve DM snapshot target's scalability by using finer grained locking. Requires some list_bl interface improvements. - Add ability for DM integrity to use a bitmap mode, that tracks regions where data and metadata are out of sync, instead of using a journal. - Improve DM thin provisioning target to not write metadata changes to disk if the thin-pool and associated thin devices are merely activated but not used. This avoids metadata corruption due to concurrent activation of thin devices across different OS instances (e.g. split brain scenarios, which ultimately would be avoided if proper device filters were used -- but not having proper filtering has proven a very common configuration mistake) - Fix missing call to path selector type->end_io in DM multipath. This fixes reported performance problems due to inaccurate path selector IO accounting causing an imbalance of IO (e.g. avoiding issuing IO to particular path due to it seemingly being heavily used). - Fix bug in DM cache metadata's loading of its discard bitset that could lead to all cache blocks being discarded if the very first cache block was discarded (thankfully in practice the first cache block is generally in use; be it FS superblock, partition table, disk label, etc). - Add testing-only DM dust target which simulates a device that has failing sectors and/or read failures. - Fix a DM init error path reference count hang that caused boot hangs if user supplied malformed input on kernel commandline. - Fix a couple issues with DM crypt target's logging being overly verbose or lacking context. - Various other small fixes to DM init, DM multipath, DM zoned, and DM crypt. * tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (42 commits) dm: fix a couple brace coding style issues dm crypt: print device name in integrity error message dm crypt: move detailed message into debug level dm ioctl: fix hang in early create error condition dm integrity: whitespace, coding style and dead code cleanup dm integrity: implement synchronous mode for reboot handling dm integrity: handle machine reboot in bitmap mode dm integrity: add a bitmap mode dm integrity: introduce a function add_new_range_and_wait() dm integrity: allow large ranges to be described dm ingerity: pass size to dm_integrity_alloc_page_list() dm integrity: introduce rw_journal_sectors() dm integrity: update documentation dm integrity: don't report unused options dm integrity: don't check null pointer before kvfree and vfree dm integrity: correctly calculate the size of metadata area dm dust: Make dm_dust_init and dm_dust_exit static dm dust: remove redundant unsigned comparison to less than zero dm mpath: always free attached_handler_name in parse_path() dm init: fix max devices/targets checks ...
blk-stat.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_STAT_H
#define BLK_STAT_H
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/ktime.h>
#include <linux/rcupdate.h>
#include <linux/timer.h>
/**
* struct blk_stat_callback - Block statistics callback.
*
* A &struct blk_stat_callback is associated with a &struct request_queue. While
* @timer is active, that queue's request completion latencies are sorted into
* buckets by @bucket_fn and added to a per-cpu buffer, @cpu_stat. When the
* timer fires, @cpu_stat is flushed to @stat and @timer_fn is invoked.
*/
struct blk_stat_callback {
/*
* @list: RCU list of callbacks for a &struct request_queue.
*/
struct list_head list;
/**
* @timer: Timer for the next callback invocation.
*/
struct timer_list timer;
/**
* @cpu_stat: Per-cpu statistics buckets.
*/
struct blk_rq_stat __percpu *cpu_stat;
/**
* @bucket_fn: Given a request, returns which statistics bucket it
* should be accounted under. Return -1 for no bucket for this
* request.
*/
int (*bucket_fn)(const struct request *);
/**
* @buckets: Number of statistics buckets.
*/
unsigned int buckets;
/**
* @stat: Array of statistics buckets.
*/
struct blk_rq_stat *stat;
/**
* @fn: Callback function.
*/
void (*timer_fn)(struct blk_stat_callback *);
/**
* @data: Private pointer for the user.
*/
void *data;
struct rcu_head rcu;
};
struct blk_queue_stats *blk_alloc_queue_stats(void);
void blk_free_queue_stats(struct blk_queue_stats *);
void blk_stat_add(struct request *rq, u64 now);
/* record time/size info in request but not add a callback */
void blk_stat_enable_accounting(struct request_queue *q);
/**
* blk_stat_alloc_callback() - Allocate a block statistics callback.
* @timer_fn: Timer callback function.
* @bucket_fn: Bucket callback function.
* @buckets: Number of statistics buckets.
* @data: Value for the @data field of the &struct blk_stat_callback.
*
* See &struct blk_stat_callback for details on the callback functions.
*
* Return: &struct blk_stat_callback on success or NULL on ENOMEM.
*/
struct blk_stat_callback *
blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
int (*bucket_fn)(const struct request *),
unsigned int buckets, void *data);
/**
* blk_stat_add_callback() - Add a block statistics callback to be run on a
* request queue.
* @q: The request queue.
* @cb: The callback.
*
* Note that a single &struct blk_stat_callback can only be added to a single
* &struct request_queue.
*/
void blk_stat_add_callback(struct request_queue *q,
struct blk_stat_callback *cb);
/**
* blk_stat_remove_callback() - Remove a block statistics callback from a
* request queue.
* @q: The request queue.
* @cb: The callback.
*
* When this returns, the callback is not running on any CPUs and will not be
* called again unless readded.
*/
void blk_stat_remove_callback(struct request_queue *q,
struct blk_stat_callback *cb);
/**
* blk_stat_free_callback() - Free a block statistics callback.
* @cb: The callback.
*
* @cb may be NULL, in which case this does nothing. If it is not NULL, @cb must
* not be associated with a request queue. I.e., if it was previously added with
* blk_stat_add_callback(), it must also have been removed since then with
* blk_stat_remove_callback().
*/
void blk_stat_free_callback(struct blk_stat_callback *cb);
/**
* blk_stat_is_active() - Check if a block statistics callback is currently
* gathering statistics.
* @cb: The callback.
*/
static inline bool blk_stat_is_active(struct blk_stat_callback *cb)
{
return timer_pending(&cb->timer);
}
/**
* blk_stat_activate_nsecs() - Gather block statistics during a time window in
* nanoseconds.
* @cb: The callback.
* @nsecs: Number of nanoseconds to gather statistics for.
*
* The timer callback will be called when the window expires.
*/
static inline void blk_stat_activate_nsecs(struct blk_stat_callback *cb,
u64 nsecs)
{
mod_timer(&cb->timer, jiffies + nsecs_to_jiffies(nsecs));
}
static inline void blk_stat_deactivate(struct blk_stat_callback *cb)
{
del_timer_sync(&cb->timer);
}
/**
* blk_stat_activate_msecs() - Gather block statistics during a time window in
* milliseconds.
* @cb: The callback.
* @msecs: Number of milliseconds to gather statistics for.
*
* The timer callback will be called when the window expires.
*/
static inline void blk_stat_activate_msecs(struct blk_stat_callback *cb,
unsigned int msecs)
{
mod_timer(&cb->timer, jiffies + msecs_to_jiffies(msecs));
}
void blk_rq_stat_add(struct blk_rq_stat *, u64);
void blk_rq_stat_sum(struct blk_rq_stat *, struct blk_rq_stat *);
void blk_rq_stat_init(struct blk_rq_stat *);
#endif
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