Release 4.7 drivers/md/dm-mpath.c
/*
* Copyright (C) 2003 Sistina Software Limited.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include "dm.h"
#include "dm-path-selector.h"
#include "dm-uevent.h"
#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <scsi/scsi_dh.h>
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#define DM_MSG_PREFIX "multipath"
#define DM_PG_INIT_DELAY_MSECS 2000
#define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1)
/* Path properties */
struct pgpath {
struct list_head list;
struct priority_group *pg; /* Owning PG */
unsigned fail_count; /* Cumulative failure count */
struct dm_path path;
struct delayed_work activate_path;
bool is_active:1; /* Path status */
};
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
/*
* Paths are grouped into Priority Groups and numbered from 1 upwards.
* Each has a path selector which controls which path gets used.
*/
struct priority_group {
struct list_head list;
struct multipath *m; /* Owning multipath instance */
struct path_selector ps;
unsigned pg_num; /* Reference number */
unsigned nr_pgpaths; /* Number of paths in PG */
struct list_head pgpaths;
bool bypassed:1; /* Temporarily bypass this PG? */
};
/* Multipath context */
struct multipath {
struct list_head list;
struct dm_target *ti;
const char *hw_handler_name;
char *hw_handler_params;
spinlock_t lock;
unsigned nr_priority_groups;
struct list_head priority_groups;
wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */
struct pgpath *current_pgpath;
struct priority_group *current_pg;
struct priority_group *next_pg; /* Switch to this PG if set */
unsigned long flags; /* Multipath state flags */
unsigned pg_init_retries; /* Number of times to retry pg_init */
unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */
atomic_t nr_valid_paths; /* Total number of usable paths */
atomic_t pg_init_in_progress; /* Only one pg_init allowed at once */
atomic_t pg_init_count; /* Number of times pg_init called */
/*
* We must use a mempool of dm_mpath_io structs so that we
* can resubmit bios on error.
*/
mempool_t *mpio_pool;
struct mutex work_mutex;
struct work_struct trigger_event;
};
/*
* Context information attached to each bio we process.
*/
struct dm_mpath_io {
struct pgpath *pgpath;
size_t nr_bytes;
};
typedef int (*action_fn) (struct pgpath *pgpath);
static struct kmem_cache *_mpio_cache;
static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
static void trigger_event(struct work_struct *work);
static void activate_path(struct work_struct *work);
/*-----------------------------------------------
* Multipath state flags.
*-----------------------------------------------*/
#define MPATHF_QUEUE_IO 0
/* Must we queue all I/O? */
#define MPATHF_QUEUE_IF_NO_PATH 1
/* Queue I/O if last path fails? */
#define MPATHF_SAVED_QUEUE_IF_NO_PATH 2
/* Saved state during suspension */
#define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3
/* If there's already a hw_handler present, don't change it. */
#define MPATHF_PG_INIT_DISABLED 4
/* pg_init is not currently allowed */
#define MPATHF_PG_INIT_REQUIRED 5
/* pg_init needs calling? */
#define MPATHF_PG_INIT_DELAY_RETRY 6
/* Delay pg_init retry? */
/*-----------------------------------------------
* Allocation routines
*-----------------------------------------------*/
static struct pgpath *alloc_pgpath(void)
{
struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL);
if (pgpath) {
pgpath->is_active = true;
INIT_DELAYED_WORK(&pgpath->activate_path, activate_path);
}
return pgpath;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 37 | 72.55% | 1 | 16.67% |
| mike anderson | mike anderson | 6 | 11.76% | 1 | 16.67% |
| chandra seetharaman | chandra seetharaman | 6 | 11.76% | 2 | 33.33% |
| mike snitzer | mike snitzer | 1 | 1.96% | 1 | 16.67% |
| michal miroslaw | michal miroslaw | 1 | 1.96% | 1 | 16.67% |
| Total | 51 | 100.00% | 6 | 100.00% |
static void free_pgpath(struct pgpath *pgpath)
{
kfree(pgpath);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 16 | 100.00% | 1 | 100.00% |
| Total | 16 | 100.00% | 1 | 100.00% |
static struct priority_group *alloc_priority_group(void)
{
struct priority_group *pg;
pg = kzalloc(sizeof(*pg), GFP_KERNEL);
if (pg)
INIT_LIST_HEAD(&pg->pgpaths);
return pg;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 42 | 97.67% | 1 | 50.00% |
| michal miroslaw | michal miroslaw | 1 | 2.33% | 1 | 50.00% |
| Total | 43 | 100.00% | 2 | 100.00% |
static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
{
struct pgpath *pgpath, *tmp;
list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
list_del(&pgpath->list);
dm_put_device(ti, pgpath->path.dev);
free_pgpath(pgpath);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 60 | 100.00% | 1 | 100.00% |
| Total | 60 | 100.00% | 1 | 100.00% |
static void free_priority_group(struct priority_group *pg,
struct dm_target *ti)
{
struct path_selector *ps = &pg->ps;
if (ps->type) {
ps->type->destroy(ps);
dm_put_path_selector(ps->type);
}
free_pgpaths(&pg->pgpaths, ti);
kfree(pg);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 65 | 100.00% | 2 | 100.00% |
| Total | 65 | 100.00% | 2 | 100.00% |
static struct multipath *alloc_multipath(struct dm_target *ti, bool use_blk_mq)
{
struct multipath *m;
m = kzalloc(sizeof(*m), GFP_KERNEL);
if (m) {
INIT_LIST_HEAD(&m->priority_groups);
spin_lock_init(&m->lock);
set_bit(MPATHF_QUEUE_IO, &m->flags);
atomic_set(&m->nr_valid_paths, 0);
atomic_set(&m->pg_init_in_progress, 0);
atomic_set(&m->pg_init_count, 0);
m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
INIT_WORK(&m->trigger_event, trigger_event);
init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
m->mpio_pool = NULL;
if (!use_blk_mq) {
unsigned min_ios = dm_get_reserved_rq_based_ios();
m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache);
if (!m->mpio_pool) {
kfree(m);
return NULL;
}
}
m->ti = ti;
ti->private = m;
}
return m;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 90 | 47.37% | 2 | 16.67% |
| mike snitzer | mike snitzer | 60 | 31.58% | 4 | 33.33% |
| michal miroslaw | michal miroslaw | 17 | 8.95% | 2 | 16.67% |
| mike anderson | mike anderson | 8 | 4.21% | 1 | 8.33% |
| kiyoshi ueda | kiyoshi ueda | 8 | 4.21% | 1 | 8.33% |
| chandra seetharaman | chandra seetharaman | 6 | 3.16% | 1 | 8.33% |
| matthew dobson | matthew dobson | 1 | 0.53% | 1 | 8.33% |
| Total | 190 | 100.00% | 12 | 100.00% |
static void free_multipath(struct multipath *m)
{
struct priority_group *pg, *tmp;
list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) {
list_del(&pg->list);
free_priority_group(pg, m->ti);
}
kfree(m->hw_handler_name);
kfree(m->hw_handler_params);
mempool_destroy(m->mpio_pool);
kfree(m);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 64 | 86.49% | 2 | 50.00% |
| chandra seetharaman | chandra seetharaman | 10 | 13.51% | 2 | 50.00% |
| Total | 74 | 100.00% | 4 | 100.00% |
static struct dm_mpath_io *get_mpio(union map_info *info)
{
return info->ptr;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 17 | 94.44% | 1 | 50.00% |
| jun'ichi nomura | jun'ichi nomura | 1 | 5.56% | 1 | 50.00% |
| Total | 18 | 100.00% | 2 | 100.00% |
static struct dm_mpath_io *set_mpio(struct multipath *m, union map_info *info)
{
struct dm_mpath_io *mpio;
if (!m->mpio_pool) {
/* Use blk-mq pdu memory requested via per_io_data_size */
mpio = get_mpio(info);
memset(mpio, 0, sizeof(*mpio));
return mpio;
}
mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
if (!mpio)
return NULL;
memset(mpio, 0, sizeof(*mpio));
info->ptr = mpio;
return mpio;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| jun'ichi nomura | jun'ichi nomura | 57 | 58.76% | 1 | 33.33% |
| mike snitzer | mike snitzer | 40 | 41.24% | 2 | 66.67% |
| Total | 97 | 100.00% | 3 | 100.00% |
static void clear_request_fn_mpio(struct multipath *m, union map_info *info)
{
/* Only needed for non blk-mq (.request_fn) multipath */
if (m->mpio_pool) {
struct dm_mpath_io *mpio = info->ptr;
info->ptr = NULL;
mempool_free(mpio, m->mpio_pool);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| jun'ichi nomura | jun'ichi nomura | 39 | 79.59% | 1 | 33.33% |
| mike snitzer | mike snitzer | 10 | 20.41% | 2 | 66.67% |
| Total | 49 | 100.00% | 3 | 100.00% |
/*-----------------------------------------------
* Path selection
*-----------------------------------------------*/
static int __pg_init_all_paths(struct multipath *m)
{
struct pgpath *pgpath;
unsigned long pg_init_delay = 0;
if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
return 0;
atomic_inc(&m->pg_init_count);
clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
/* Check here to reset pg_init_required */
if (!m->current_pg)
return 0;
if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags))
pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ?
m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS);
list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
/* Skip failed paths */
if (!pgpath->is_active)
continue;
if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path,
pg_init_delay))
atomic_inc(&m->pg_init_in_progress);
}
return atomic_read(&m->pg_init_in_progress);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 56 | 36.60% | 1 | 16.67% |
| mike snitzer | mike snitzer | 37 | 24.18% | 2 | 33.33% |
| chandra seetharaman | chandra seetharaman | 31 | 20.26% | 1 | 16.67% |
| hannes reinecke | hannes reinecke | 29 | 18.95% | 2 | 33.33% |
| Total | 153 | 100.00% | 6 | 100.00% |
static int pg_init_all_paths(struct multipath *m)
{
int r;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
r = __pg_init_all_paths(m);
spin_unlock_irqrestore(&m->lock, flags);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 48 | 100.00% | 1 | 100.00% |
| Total | 48 | 100.00% | 1 | 100.00% |
static void __switch_pg(struct multipath *m, struct priority_group *pg)
{
m->current_pg = pg;
/* Must we initialise the PG first, and queue I/O till it's ready? */
if (m->hw_handler_name) {
set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
set_bit(MPATHF_QUEUE_IO, &m->flags);
} else {
clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
clear_bit(MPATHF_QUEUE_IO, &m->flags);
}
atomic_set(&m->pg_init_count, 0);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 42 | 50.00% | 2 | 28.57% |
| mike snitzer | mike snitzer | 35 | 41.67% | 3 | 42.86% |
| dave wysochanski | dave wysochanski | 5 | 5.95% | 1 | 14.29% |
| chandra seetharaman | chandra seetharaman | 2 | 2.38% | 1 | 14.29% |
| Total | 84 | 100.00% | 7 | 100.00% |
static struct pgpath *choose_path_in_pg(struct multipath *m,
struct priority_group *pg,
size_t nr_bytes)
{
unsigned long flags;
struct dm_path *path;
struct pgpath *pgpath;
path = pg->ps.type->select_path(&pg->ps, nr_bytes);
if (!path)
return ERR_PTR(-ENXIO);
pgpath = path_to_pgpath(path);
if (unlikely(lockless_dereference(m->current_pg) != pg)) {
/* Only update current_pgpath if pg changed */
spin_lock_irqsave(&m->lock, flags);
m->current_pgpath = pgpath;
__switch_pg(m, pg);
spin_unlock_irqrestore(&m->lock, flags);
}
return pgpath;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 68 | 54.40% | 1 | 25.00% |
| mike snitzer | mike snitzer | 52 | 41.60% | 1 | 25.00% |
| kiyoshi ueda | kiyoshi ueda | 4 | 3.20% | 1 | 25.00% |
| josef 'jeff' sipek | josef 'jeff' sipek | 1 | 0.80% | 1 | 25.00% |
| Total | 125 | 100.00% | 4 | 100.00% |
static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
{
unsigned long flags;
struct priority_group *pg;
struct pgpath *pgpath;
bool bypassed = true;
if (!atomic_read(&m->nr_valid_paths)) {
clear_bit(MPATHF_QUEUE_IO, &m->flags);
goto failed;
}
/* Were we instructed to switch PG? */
if (lockless_dereference(m->next_pg)) {
spin_lock_irqsave(&m->lock, flags);
pg = m->next_pg;
if (!pg) {
spin_unlock_irqrestore(&m->lock, flags);
goto check_current_pg;
}
m->next_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath))
return pgpath;
}
/* Don't change PG until it has no remaining paths */
check_current_pg:
pg = lockless_dereference(m->current_pg);
if (pg) {
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath))
return pgpath;
}
/*
* Loop through priority groups until we find a valid path.
* First time we skip PGs marked 'bypassed'.
* Second time we only try the ones we skipped, but set
* pg_init_delay_retry so we do not hammer controllers.
*/
do {
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed == bypassed)
continue;
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath)) {
if (!bypassed)
set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
return pgpath;
}
}
} while (bypassed--);
failed:
spin_lock_irqsave(&m->lock, flags);
m->current_pgpath = NULL;
m->current_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
return NULL;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 156 | 53.42% | 4 | 50.00% |
| alasdair kergon | alasdair kergon | 111 | 38.01% | 1 | 12.50% |
| mike christie | mike christie | 11 | 3.77% | 1 | 12.50% |
| kiyoshi ueda | kiyoshi ueda | 9 | 3.08% | 1 | 12.50% |
| benjamin marzinski | benjamin marzinski | 5 | 1.71% | 1 | 12.50% |
| Total | 292 | 100.00% | 8 | 100.00% |
/*
* Check whether bios must be queued in the device-mapper core rather
* than here in the target.
*
* If m->queue_if_no_path and m->saved_queue_if_no_path hold the
* same value then we are not between multipath_presuspend()
* and multipath_resume() calls and we have no need to check
* for the DMF_NOFLUSH_SUSPENDING flag.
*/
static int must_push_back(struct multipath *m)
{
return (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) ||
((test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) !=
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) &&
dm_noflush_suspending(m->ti)));
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 26 | 47.27% | 1 | 25.00% |
| mike snitzer | mike snitzer | 24 | 43.64% | 2 | 50.00% |
| hannes reinecke | hannes reinecke | 5 | 9.09% | 1 | 25.00% |
| Total | 55 | 100.00% | 4 | 100.00% |
/*
* Map cloned requests
*/
static int __multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context,
struct request *rq, struct request **__clone)
{
struct multipath *m = ti->private;
int r = DM_MAPIO_REQUEUE;
size_t nr_bytes = clone ? blk_rq_bytes(clone) : blk_rq_bytes(rq);
struct pgpath *pgpath;
struct block_device *bdev;
struct dm_mpath_io *mpio;
/* Do we need to select a new pgpath? */
pgpath = lockless_dereference(m->current_pgpath);
if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags))
pgpath = choose_pgpath(m, nr_bytes);
if (!pgpath) {
if (!must_push_back(m))
r = -EIO; /* Failed */
return r;
} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
pg_init_all_paths(m);
return r;
}
mpio = set_mpio(m, map_context);
if (!mpio)
/* ENOMEM, requeue */
return r;
mpio->pgpath = pgpath;
mpio->nr_bytes = nr_bytes;
bdev = pgpath->path.dev->bdev;
if (clone) {
/*
* Old request-based interface: allocated clone is passed in.
* Used by: .request_fn stacked on .request_fn path(s).
*/
clone->q = bdev_get_queue(bdev);
clone->rq_disk = bdev->bd_disk;
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
} else {
/*
* blk-mq request-based interface; used by both:
* .request_fn stacked on blk-mq path(s) and
* blk-mq stacked on blk-mq path(s).
*/
*__clone = blk_mq_alloc_request(bdev_get_queue(bdev),
rq_data_dir(rq), BLK_MQ_REQ_NOWAIT);
if (IS_ERR(*__clone)) {
/* ENOMEM, requeue */
clear_request_fn_mpio(m, map_context);
return r;
}
(*__clone)->bio = (*__clone)->biotail = NULL;
(*__clone)->rq_disk = bdev->bd_disk;
(*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT;
}
if (pgpath->pg->ps.type->start_io)
pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
&pgpath->path,
nr_bytes);
return DM_MAPIO_REMAPPED;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 176 | 49.30% | 10 | 58.82% |
| kiyoshi ueda | kiyoshi ueda | 74 | 20.73% | 2 | 11.76% |
| alasdair kergon | alasdair kergon | 57 | 15.97% | 1 | 5.88% |
| hannes reinecke | hannes reinecke | 26 | 7.28% | 2 | 11.76% |
| keith busch | keith busch | 16 | 4.48% | 1 | 5.88% |
| jun'ichi nomura | jun'ichi nomura | 8 | 2.24% | 1 | 5.88% |
| Total | 357 | 100.00% | 17 | 100.00% |
static int multipath_map(struct dm_target *ti, struct request *clone,
union map_info *map_context)
{
return __multipath_map(ti, clone, map_context, NULL, NULL);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 35 | 100.00% | 1 | 100.00% |
| Total | 35 | 100.00% | 1 | 100.00% |
static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
union map_info *map_context,
struct request **clone)
{
return __multipath_map(ti, NULL, map_context, rq, clone);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 41 | 100.00% | 1 | 100.00% |
| Total | 41 | 100.00% | 1 | 100.00% |
static void multipath_release_clone(struct request *clone)
{
blk_mq_free_request(clone);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 16 | 100.00% | 2 | 100.00% |
| Total | 16 | 100.00% | 2 | 100.00% |
/*
* If we run out of usable paths, should we queue I/O or error it?
*/
static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
bool save_old_value)
{
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
if (save_old_value) {
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
else
clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
} else {
if (queue_if_no_path)
set_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
else
clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
}
if (queue_if_no_path)
set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
else
clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
spin_unlock_irqrestore(&m->lock, flags);
if (!queue_if_no_path)
dm_table_run_md_queue_async(m->ti->table);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 76 | 50.67% | 2 | 28.57% |
| alasdair kergon | alasdair kergon | 60 | 40.00% | 3 | 42.86% |
| hannes reinecke | hannes reinecke | 14 | 9.33% | 2 | 28.57% |
| Total | 150 | 100.00% | 7 | 100.00% |
/*
* An event is triggered whenever a path is taken out of use.
* Includes path failure and PG bypass.
*/
static void trigger_event(struct work_struct *work)
{
struct multipath *m =
container_of(work, struct multipath, trigger_event);
dm_table_event(m->ti->table);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 25 | 71.43% | 1 | 50.00% |
| david howells | david howells | 10 | 28.57% | 1 | 50.00% |
| Total | 35 | 100.00% | 2 | 100.00% |
/*-----------------------------------------------------------------
* Constructor/argument parsing:
* <#multipath feature args> [<arg>]*
* <#hw_handler args> [hw_handler [<arg>]*]
* <#priority groups>
* <initial priority group>
* [<selector> <#selector args> [<arg>]*
* <#paths> <#per-path selector args>
* [<path> [<arg>]* ]+ ]+
*---------------------------------------------------------------*/
static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg,
struct dm_target *ti)
{
int r;
struct path_selector_type *pst;
unsigned ps_argc;
static struct dm_arg _args[] = {
{0, 1024, "invalid number of path selector args"},
};
pst = dm_get_path_selector(dm_shift_arg(as));
if (!pst) {
ti->error = "unknown path selector type";
return -EINVAL;
}
r = dm_read_arg_group(_args, as, &ps_argc, &ti->error);
if (r) {
dm_put_path_selector(pst);
return -EINVAL;
}
r = pst->create(&pg->ps, ps_argc, as->argv);
if (r) {
dm_put_path_selector(pst);
ti->error = "path selector constructor failed";
return r;
}
pg->ps.type = pst;
dm_consume_args(as, ps_argc);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 149 | 91.41% | 2 | 50.00% |
| mike snitzer | mike snitzer | 7 | 4.29% | 1 | 25.00% |
| mikulas patocka | mikulas patocka | 7 | 4.29% | 1 | 25.00% |
| Total | 163 | 100.00% | 4 | 100.00% |
static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps,
struct dm_target *ti)
{
int r;
struct pgpath *p;
struct multipath *m = ti->private;
struct request_queue *q = NULL;
const char *attached_handler_name;
/* we need at least a path arg */
if (as->argc < 1) {
ti->error = "no device given";
return ERR_PTR(-EINVAL);
}
p = alloc_pgpath();
if (!p)
return ERR_PTR(-ENOMEM);
r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table),
&p->path.dev);
if (r) {
ti->error = "error getting device";
goto bad;
}
if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) || m->hw_handler_name)
q = bdev_get_queue(p->path.dev->bdev);
if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
retain:
attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
if (attached_handler_name) {
/*
* Reset hw_handler_name to match the attached handler
* and clear any hw_handler_params associated with the
* ignored handler.
*
* NB. This modifies the table line to show the actual
* handler instead of the original table passed in.
*/
kfree(m->hw_handler_name);
m->hw_handler_name = attached_handler_name;
kfree(m->hw_handler_params);
m->hw_handler_params = NULL;
}
}
if (m->hw_handler_name) {
r = scsi_dh_attach(q, m->hw_handler_name);
if (r == -EBUSY) {
char b[BDEVNAME_SIZE];
printk(KERN_INFO "dm-mpath: retaining handler on device %s\n",
bdevname(p->path.dev->bdev, b));
goto retain;
}
if (r < 0) {
ti->error = "error attaching hardware handler";
dm_put_device(ti, p->path.dev);
goto bad;
}
if (m->hw_handler_params) {
r = scsi_dh_set_params(q, m->hw_handler_params);
if (r < 0) {
ti->error = "unable to set hardware "
"handler parameters";
dm_put_device(ti, p->path.dev);
goto bad;
}
}
}
r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error);
if (r) {
dm_put_device(ti, p->path.dev);
goto bad;
}
return p;
bad:
free_pgpath(p);
return ERR_PTR(r);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 162 | 38.76% | 1 | 11.11% |
| mike snitzer | mike snitzer | 89 | 21.29% | 3 | 33.33% |
| hannes reinecke | hannes reinecke | 80 | 19.14% | 2 | 22.22% |
| chandra seetharaman | chandra seetharaman | 48 | 11.48% | 1 | 11.11% |
| christoph hellwig | christoph hellwig | 25 | 5.98% | 1 | 11.11% |
| benjamin marzinski | benjamin marzinski | 14 | 3.35% | 1 | 11.11% |
| Total | 418 | 100.00% | 9 | 100.00% |
static struct priority_group *parse_priority_group(struct dm_arg_set *as,
struct multipath *m)
{
static struct dm_arg _args[] = {
{1, 1024, "invalid number of paths"},
{0, 1024, "invalid number of selector args"}
};
int r;
unsigned i, nr_selector_args, nr_args;
struct priority_group *pg;
struct dm_target *ti = m->ti;
if (as->argc < 2) {
as->argc = 0;
ti->error = "not enough priority group arguments";
return ERR_PTR(-EINVAL);
}
pg = alloc_priority_group();
if (!pg) {
ti->error = "couldn't allocate priority group";
return ERR_PTR(-ENOMEM);
}
pg->m = m;
r = parse_path_selector(as, pg, ti);
if (r)
goto bad;
/*
* read the paths
*/
r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error);
if (r)
goto bad;
r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error);
if (r)
goto bad;
nr_args = 1 + nr_selector_args;
for (i = 0; i < pg->nr_pgpaths; i++) {
struct pgpath *pgpath;
struct dm_arg_set path_args;
if (as->argc < nr_args) {
ti->error = "not enough path parameters";
r = -EINVAL;
goto bad;
}
path_args.argc = nr_args;
path_args.argv = as->argv;
pgpath = parse_path(&path_args, &pg->ps, ti);
if (IS_ERR(pgpath)) {
r = PTR_ERR(pgpath);
goto bad;
}
pgpath->pg = pg;
list_add_tail(&pgpath->list, &pg->pgpaths);
dm_consume_args(as, nr_args);
}
return pg;
bad:
free_priority_group(pg, ti);
return ERR_PTR(r);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 287 | 83.19% | 3 | 42.86% |
| benjamin marzinski | benjamin marzinski | 27 | 7.83% | 1 | 14.29% |
| mike snitzer | mike snitzer | 14 | 4.06% | 1 | 14.29% |
| michal miroslaw | michal miroslaw | 9 | 2.61% | 1 | 14.29% |
| mikulas patocka | mikulas patocka | 8 | 2.32% | 1 | 14.29% |
| Total | 345 | 100.00% | 7 | 100.00% |
static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
{
unsigned hw_argc;
int ret;
struct dm_target *ti = m->ti;
static struct dm_arg _args[] = {
{0, 1024, "invalid number of hardware handler args"},
};
if (dm_read_arg_group(_args, as, &hw_argc, &ti->error))
return -EINVAL;
if (!hw_argc)
return 0;
m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
if (hw_argc > 1) {
char *p;
int i, j, len = 4;
for (i = 0; i <= hw_argc - 2; i++)
len += strlen(as->argv[i]) + 1;
p = m->hw_handler_params = kzalloc(len, GFP_KERNEL);
if (!p) {
ti->error = "memory allocation failed";
ret = -ENOMEM;
goto fail;
}
j = sprintf(p, "%d", hw_argc - 1);
for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1)
j = sprintf(p, "%s", as->argv[i]);
}
dm_consume_args(as, hw_argc - 1);
return 0;
fail:
kfree(m->hw_handler_name);
m->hw_handler_name = NULL;
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| chandra seetharaman | chandra seetharaman | 167 | 64.23% | 4 | 44.44% |
| alasdair kergon | alasdair kergon | 75 | 28.85% | 2 | 22.22% |
| mike snitzer | mike snitzer | 9 | 3.46% | 2 | 22.22% |
| michal miroslaw | michal miroslaw | 9 | 3.46% | 1 | 11.11% |
| Total | 260 | 100.00% | 9 | 100.00% |
static int parse_features(struct dm_arg_set *as, struct multipath *m)
{
int r;
unsigned argc;
struct dm_target *ti = m->ti;
const char *arg_name;
static struct dm_arg _args[] = {
{0, 6, "invalid number of feature args"},
{1, 50, "pg_init_retries must be between 1 and 50"},
{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
};
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return -EINVAL;
if (!argc)
return 0;
do {
arg_name = dm_shift_arg(as);
argc--;
if (!strcasecmp(arg_name, "queue_if_no_path")) {
r = queue_if_no_path(m, true, false);
continue;
}
if (!strcasecmp(arg_name, "retain_attached_hw_handler")) {
set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags);
continue;
}
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
argc--;
continue;
}
if (!strcasecmp(arg_name, "pg_init_delay_msecs") &&
(argc >= 1)) {
r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error);
argc--;
continue;
}
ti->error = "Unrecognised multipath feature request";
r = -EINVAL;
} while (argc && !r);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 89 | 33.09% | 2 | 22.22% |
| dave wysochanski | dave wysochanski | 80 | 29.74% | 1 | 11.11% |
| chandra seetharaman | chandra seetharaman | 47 | 17.47% | 1 | 11.11% |
| mike snitzer | mike snitzer | 44 | 16.36% | 4 | 44.44% |
| michal miroslaw | michal miroslaw | 9 | 3.35% | 1 | 11.11% |
| Total | 269 | 100.00% | 9 | 100.00% |
static int multipath_ctr(struct dm_target *ti, unsigned int argc,
char **argv)
{
/* target arguments */
static struct dm_arg _args[] = {
{0, 1024, "invalid number of priority groups"},
{0, 1024, "invalid initial priority group number"},
};
int r;
struct multipath *m;
struct dm_arg_set as;
unsigned pg_count = 0;
unsigned next_pg_num;
bool use_blk_mq = dm_use_blk_mq(dm_table_get_md(ti->table));
as.argc = argc;
as.argv = argv;
m = alloc_multipath(ti, use_blk_mq);
if (!m) {
ti->error = "can't allocate multipath";
return -EINVAL;
}
r = parse_features(&as, m);
if (r)
goto bad;
r = parse_hw_handler(&as, m);
if (r)
goto bad;
r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error);
if (r)
goto bad;
r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error);
if (r)
goto bad;
if ((!m->nr_priority_groups && next_pg_num) ||
(m->nr_priority_groups && !next_pg_num)) {
ti->error = "invalid initial priority group";
r = -EINVAL;
goto bad;
}
/* parse the priority groups */
while (as.argc) {
struct priority_group *pg;
unsigned nr_valid_paths = atomic_read(&m->nr_valid_paths);
pg = parse_priority_group(&as, m);
if (IS_ERR(pg)) {
r = PTR_ERR(pg);
goto bad;
}
nr_valid_paths += pg->nr_pgpaths;
atomic_set(&m->nr_valid_paths, nr_valid_paths);
list_add_tail(&pg->list, &m->priority_groups);
pg_count++;
pg->pg_num = pg_count;
if (!--next_pg_num)
m->next_pg = pg;
}
if (pg_count != m->nr_priority_groups) {
ti->error = "priority group count mismatch";
r = -EINVAL;
goto bad;
}
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_write_same_bios = 1;
if (use_blk_mq)
ti->per_io_data_size = sizeof(struct dm_mpath_io);
return 0;
bad:
free_multipath(m);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 291 | 70.46% | 3 | 25.00% |
| mike snitzer | mike snitzer | 107 | 25.91% | 6 | 50.00% |
| benjamin marzinski | benjamin marzinski | 7 | 1.69% | 1 | 8.33% |
| mikulas patocka | mikulas patocka | 5 | 1.21% | 1 | 8.33% |
| michal miroslaw | michal miroslaw | 3 | 0.73% | 1 | 8.33% |
| Total | 413 | 100.00% | 12 | 100.00% |
static void multipath_wait_for_pg_init_completion(struct multipath *m)
{
DECLARE_WAITQUEUE(wait, current);
add_wait_queue(&m->pg_init_wait, &wait);
while (1) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (!atomic_read(&m->pg_init_in_progress))
break;
io_schedule();
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&m->pg_init_wait, &wait);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 68 | 95.77% | 1 | 50.00% |
| mike snitzer | mike snitzer | 3 | 4.23% | 1 | 50.00% |
| Total | 71 | 100.00% | 2 | 100.00% |
static void flush_multipath_work(struct multipath *m)
{
set_bit(MPATHF_PG_INIT_DISABLED, &m->flags);
smp_mb__after_atomic();
flush_workqueue(kmpath_handlerd);
multipath_wait_for_pg_init_completion(m);
flush_workqueue(kmultipathd);
flush_work(&m->trigger_event);
clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags);
smp_mb__after_atomic();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 27 | 45.00% | 2 | 33.33% |
| shiva krishna merla | shiva krishna merla | 16 | 26.67% | 1 | 16.67% |
| mike snitzer | mike snitzer | 10 | 16.67% | 1 | 16.67% |
| tejun heo | tejun heo | 7 | 11.67% | 2 | 33.33% |
| Total | 60 | 100.00% | 6 | 100.00% |
static void multipath_dtr(struct dm_target *ti)
{
struct multipath *m = ti->private;
flush_multipath_work(m);
free_multipath(m);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 25 | 83.33% | 1 | 25.00% |
| kiyoshi ueda | kiyoshi ueda | 4 | 13.33% | 2 | 50.00% |
| mikulas patocka | mikulas patocka | 1 | 3.33% | 1 | 25.00% |
| Total | 30 | 100.00% | 4 | 100.00% |
/*
* Take a path out of use.
*/
static int fail_path(struct pgpath *pgpath)
{
unsigned long flags;
struct multipath *m = pgpath->pg->m;
spin_lock_irqsave(&m->lock, flags);
if (!pgpath->is_active)
goto out;
DMWARN("Failing path %s.", pgpath->path.dev->name);
pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
pgpath->is_active = false;
pgpath->fail_count++;
atomic_dec(&m->nr_valid_paths);
if (pgpath == m->current_pgpath)
m->current_pgpath = NULL;
dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
pgpath->path.dev->name, atomic_read(&m->nr_valid_paths));
schedule_work(&m->trigger_event);
out:
spin_unlock_irqrestore(&m->lock, flags);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 133 | 81.60% | 3 | 50.00% |
| mike anderson | mike anderson | 21 | 12.88% | 1 | 16.67% |
| mike snitzer | mike snitzer | 9 | 5.52% | 2 | 33.33% |
| Total | 163 | 100.00% | 6 | 100.00% |
/*
* Reinstate a previously-failed path
*/
static int reinstate_path(struct pgpath *pgpath)
{
int r = 0, run_queue = 0;
unsigned long flags;
struct multipath *m = pgpath->pg->m;
unsigned nr_valid_paths;
spin_lock_irqsave(&m->lock, flags);
if (pgpath->is_active)
goto out;
DMWARN("Reinstating path %s.", pgpath->path.dev->name);
r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path);
if (r)
goto out;
pgpath->is_active = true;
nr_valid_paths = atomic_inc_return(&m->nr_valid_paths);
if (nr_valid_paths == 1) {
m->current_pgpath = NULL;
run_queue = 1;
} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
if (queue_work(kmpath_handlerd, &pgpath->activate_path.work))
atomic_inc(&m->pg_init_in_progress);
}
dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
pgpath->path.dev->name, nr_valid_paths);
schedule_work(&m->trigger_event);
out:
spin_unlock_irqrestore(&m->lock, flags);
if (run_queue)
dm_table_run_md_queue_async(m->ti->table);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 125 | 53.88% | 2 | 22.22% |
| chandra seetharaman | chandra seetharaman | 45 | 19.40% | 2 | 22.22% |
| mike snitzer | mike snitzer | 23 | 9.91% | 3 | 33.33% |
| hannes reinecke | hannes reinecke | 20 | 8.62% | 1 | 11.11% |
| mike anderson | mike anderson | 19 | 8.19% | 1 | 11.11% |
| Total | 232 | 100.00% | 9 | 100.00% |
/*
* Fail or reinstate all paths that match the provided struct dm_dev.
*/
static int action_dev(struct multipath *m, struct dm_dev *dev,
action_fn action)
{
int r = -EINVAL;
struct pgpath *pgpath;
struct priority_group *pg;
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->path.dev == dev)
r = action(pgpath);
}
}
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 73 | 97.33% | 1 | 50.00% |
| mike snitzer | mike snitzer | 2 | 2.67% | 1 | 50.00% |
| Total | 75 | 100.00% | 2 | 100.00% |
/*
* Temporarily try to avoid having to use the specified PG
*/
static void bypass_pg(struct multipath *m, struct priority_group *pg,
bool bypassed)
{
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
pg->bypassed = bypassed;
m->current_pgpath = NULL;
m->current_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
schedule_work(&m->trigger_event);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 68 | 98.55% | 2 | 66.67% |
| mike snitzer | mike snitzer | 1 | 1.45% | 1 | 33.33% |
| Total | 69 | 100.00% | 3 | 100.00% |
/*
* Switch to using the specified PG from the next I/O that gets mapped
*/
static int switch_pg_num(struct multipath *m, const char *pgstr)
{
struct priority_group *pg;
unsigned pgnum;
unsigned long flags;
char dummy;
if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
(pgnum > m->nr_priority_groups)) {
DMWARN("invalid PG number supplied to switch_pg_num");
return -EINVAL;
}
spin_lock_irqsave(&m->lock, flags);
list_for_each_entry(pg, &m->priority_groups, list) {
pg->bypassed = false;
if (--pgnum)
continue;
m->current_pgpath = NULL;
m->current_pg = NULL;
m->next_pg = pg;
}
spin_unlock_irqrestore(&m->lock, flags);
schedule_work(&m->trigger_event);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 138 | 94.52% | 2 | 50.00% |
| mikulas patocka | mikulas patocka | 7 | 4.79% | 1 | 25.00% |
| mike snitzer | mike snitzer | 1 | 0.68% | 1 | 25.00% |
| Total | 146 | 100.00% | 4 | 100.00% |
/*
* Set/clear bypassed status of a PG.
* PGs are numbered upwards from 1 in the order they were declared.
*/
static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed)
{
struct priority_group *pg;
unsigned pgnum;
char dummy;
if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
(pgnum > m->nr_priority_groups)) {
DMWARN("invalid PG number supplied to bypass_pg");
return -EINVAL;
}
list_for_each_entry(pg, &m->priority_groups, list) {
if (!--pgnum)
break;
}
bypass_pg(m, pg, bypassed);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 95 | 92.23% | 1 | 33.33% |
| mikulas patocka | mikulas patocka | 7 | 6.80% | 1 | 33.33% |
| mike snitzer | mike snitzer | 1 | 0.97% | 1 | 33.33% |
| Total | 103 | 100.00% | 3 | 100.00% |
/*
* Should we retry pg_init immediately?
*/
static bool pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
{
unsigned long flags;
bool limit_reached = false;
spin_lock_irqsave(&m->lock, flags);
if (atomic_read(&m->pg_init_count) <= m->pg_init_retries &&
!test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
else
limit_reached = true;
spin_unlock_irqrestore(&m->lock, flags);
return limit_reached;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| dave wysochanski | dave wysochanski | 62 | 70.45% | 1 | 20.00% |
| mike snitzer | mike snitzer | 22 | 25.00% | 3 | 60.00% |
| shiva krishna merla | shiva krishna merla | 4 | 4.55% | 1 | 20.00% |
| Total | 88 | 100.00% | 5 | 100.00% |
static void pg_init_done(void *data, int errors)
{
struct pgpath *pgpath = data;
struct priority_group *pg = pgpath->pg;
struct multipath *m = pg->m;
unsigned long flags;
bool delay_retry = false;
/* device or driver problems */
switch (errors) {
case SCSI_DH_OK:
break;
case SCSI_DH_NOSYS:
if (!m->hw_handler_name) {
errors = 0;
break;
}
DMERR("Could not failover the device: Handler scsi_dh_%s "
"Error %d.", m->hw_handler_name, errors);
/*
* Fail path for now, so we do not ping pong
*/
fail_path(pgpath);
break;
case SCSI_DH_DEV_TEMP_BUSY:
/*
* Probably doing something like FW upgrade on the
* controller so try the other pg.
*/
bypass_pg(m, pg, true);
break;
case SCSI_DH_RETRY:
/* Wait before retrying. */
delay_retry = 1;
case SCSI_DH_IMM_RETRY:
case SCSI_DH_RES_TEMP_UNAVAIL:
if (pg_init_limit_reached(m, pgpath))
fail_path(pgpath);
errors = 0;
break;
case SCSI_DH_DEV_OFFLINED:
default:
/*
* We probably do not want to fail the path for a device
* error, but this is what the old dm did. In future
* patches we can do more advanced handling.
*/
fail_path(pgpath);
}
spin_lock_irqsave(&m->lock, flags);
if (errors) {
if (pgpath == m->current_pgpath) {
DMERR("Could not failover device. Error %d.", errors);
m->current_pgpath = NULL;
m->current_pg = NULL;
}
} else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
pg->bypassed = false;
if (atomic_dec_return(&m->pg_init_in_progress) > 0)
/* Activations of other paths are still on going */
goto out;
if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
if (delay_retry)
set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
else
clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
if (__pg_init_all_paths(m))
goto out;
}
clear_bit(MPATHF_QUEUE_IO, &m->flags);
/*
* Wake up any thread waiting to suspend.
*/
wake_up(&m->pg_init_wait);
out:
spin_unlock_irqrestore(&m->lock, flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| chandra seetharaman | chandra seetharaman | 222 | 71.15% | 4 | 30.77% |
| mike snitzer | mike snitzer | 56 | 17.95% | 4 | 30.77% |
| kiyoshi ueda | kiyoshi ueda | 18 | 5.77% | 2 | 15.38% |
| hannes reinecke | hannes reinecke | 11 | 3.53% | 1 | 7.69% |
| babu moger | babu moger | 5 | 1.60% | 2 | 15.38% |
| Total | 312 | 100.00% | 13 | 100.00% |
static void activate_path(struct work_struct *work)
{
struct pgpath *pgpath =
container_of(work, struct pgpath, activate_path.work);
if (pgpath->is_active)
scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
pg_init_done, pgpath);
else
pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| chandra seetharaman | chandra seetharaman | 46 | 76.67% | 4 | 80.00% |
| hannes reinecke | hannes reinecke | 14 | 23.33% | 1 | 20.00% |
| Total | 60 | 100.00% | 5 | 100.00% |
static int noretry_error(int error)
{
switch (error) {
case -EOPNOTSUPP:
case -EREMOTEIO:
case -EILSEQ:
case -ENODATA:
case -ENOSPC:
return 1;
}
/* Anything else could be a path failure, so should be retried */
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| hannes reinecke | hannes reinecke | 38 | 90.48% | 1 | 50.00% |
| jun'ichi nomura | jun'ichi nomura | 4 | 9.52% | 1 | 50.00% |
| Total | 42 | 100.00% | 2 | 100.00% |
/*
* end_io handling
*/
static int do_end_io(struct multipath *m, struct request *clone,
int error, struct dm_mpath_io *mpio)
{
/*
* We don't queue any clone request inside the multipath target
* during end I/O handling, since those clone requests don't have
* bio clones. If we queue them inside the multipath target,
* we need to make bio clones, that requires memory allocation.
* (See drivers/md/dm.c:end_clone_bio() about why the clone requests
* don't have bio clones.)
* Instead of queueing the clone request here, we queue the original
* request into dm core, which will remake a clone request and
* clone bios for it and resubmit it later.
*/
int r = DM_ENDIO_REQUEUE;
if (!error && !clone->errors)
return 0; /* I/O complete */
if (noretry_error(error))
return error;
if (mpio->pgpath)
fail_path(mpio->pgpath);
if (!atomic_read(&m->nr_valid_paths)) {
if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
if (!must_push_back(m))
r = -EIO;
} else {
if (error == -EBADE)
r = error;
}
}
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 54 | 43.20% | 3 | 27.27% |
| hannes reinecke | hannes reinecke | 27 | 21.60% | 2 | 18.18% |
| kiyoshi ueda | kiyoshi ueda | 24 | 19.20% | 1 | 9.09% |
| mike snitzer | mike snitzer | 18 | 14.40% | 4 | 36.36% |
| lars marowsky-bree | lars marowsky-bree | 2 | 1.60% | 1 | 9.09% |
| Total | 125 | 100.00% | 11 | 100.00% |
static int multipath_end_io(struct dm_target *ti, struct request *clone,
int error, union map_info *map_context)
{
struct multipath *m = ti->private;
struct dm_mpath_io *mpio = get_mpio(map_context);
struct pgpath *pgpath;
struct path_selector *ps;
int r;
BUG_ON(!mpio);
r = do_end_io(m, clone, error, mpio);
pgpath = mpio->pgpath;
if (pgpath) {
ps = &pgpath->pg->ps;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
}
clear_request_fn_mpio(m, map_context);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 107 | 81.06% | 2 | 28.57% |
| jun'ichi nomura | jun'ichi nomura | 8 | 6.06% | 1 | 14.29% |
| kiyoshi ueda | kiyoshi ueda | 7 | 5.30% | 2 | 28.57% |
| wei yongjun | wei yongjun | 6 | 4.55% | 1 | 14.29% |
| mike snitzer | mike snitzer | 4 | 3.03% | 1 | 14.29% |
| Total | 132 | 100.00% | 7 | 100.00% |
/*
* Suspend can't complete until all the I/O is processed so if
* the last path fails we must error any remaining I/O.
* Note that if the freeze_bdev fails while suspending, the
* queue_if_no_path state is lost - userspace should reset it.
*/
static void multipath_presuspend(struct dm_target *ti)
{
struct multipath *m = ti->private;
queue_if_no_path(m, false, true);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 27 | 93.10% | 2 | 66.67% |
| mike snitzer | mike snitzer | 2 | 6.90% | 1 | 33.33% |
| Total | 29 | 100.00% | 3 | 100.00% |
static void multipath_postsuspend(struct dm_target *ti)
{
struct multipath *m = ti->private;
mutex_lock(&m->work_mutex);
flush_multipath_work(m);
mutex_unlock(&m->work_mutex);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike anderson | mike anderson | 25 | 60.98% | 1 | 33.33% |
| kiyoshi ueda | kiyoshi ueda | 16 | 39.02% | 2 | 66.67% |
| Total | 41 | 100.00% | 3 | 100.00% |
/*
* Restore the queue_if_no_path setting.
*/
static void multipath_resume(struct dm_target *ti)
{
struct multipath *m = ti->private;
if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags))
set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
else
clear_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
smp_mb__after_atomic();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 36 | 64.29% | 2 | 66.67% |
| mike snitzer | mike snitzer | 20 | 35.71% | 1 | 33.33% |
| Total | 56 | 100.00% | 3 | 100.00% |
/*
* Info output has the following format:
* num_multipath_feature_args [multipath_feature_args]*
* num_handler_status_args [handler_status_args]*
* num_groups init_group_number
* [A|D|E num_ps_status_args [ps_status_args]*
* num_paths num_selector_args
* [path_dev A|F fail_count [selector_args]* ]+ ]+
*
* Table output has the following format (identical to the constructor string):
* num_feature_args [features_args]*
* num_handler_args hw_handler [hw_handler_args]*
* num_groups init_group_number
* [priority selector-name num_ps_args [ps_args]*
* num_paths num_selector_args [path_dev [selector_args]* ]+ ]+
*/
static void multipath_status(struct dm_target *ti, status_type_t type,
unsigned status_flags, char *result, unsigned maxlen)
{
int sz = 0;
unsigned long flags;
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *p;
unsigned pg_num;
char state;
spin_lock_irqsave(&m->lock, flags);
/* Features */
if (type == STATUSTYPE_INFO)
DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags),
atomic_read(&m->pg_init_count));
else {
DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) +
(m->pg_init_retries > 0) * 2 +
(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags));
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
DMEMIT("queue_if_no_path ");
if (m->pg_init_retries)
DMEMIT("pg_init_retries %u ", m->pg_init_retries);
if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT)
DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags))
DMEMIT("retain_attached_hw_handler ");
}
if (!m->hw_handler_name || type == STATUSTYPE_INFO)
DMEMIT("0 ");
else
DMEMIT("1 %s ", m->hw_handler_name);
DMEMIT("%u ", m->nr_priority_groups);
if (m->next_pg)
pg_num = m->next_pg->pg_num;
else if (m->current_pg)
pg_num = m->current_pg->pg_num;
else
pg_num = (m->nr_priority_groups ? 1 : 0);
DMEMIT("%u ", pg_num);
switch (type) {
case STATUSTYPE_INFO:
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed)
state = 'D'; /* Disabled */
else if (pg == m->current_pg)
state = 'A'; /* Currently Active */
else
state = 'E'; /* Enabled */
DMEMIT("%c ", state);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps, NULL, type,
result + sz,
maxlen - sz);
else
DMEMIT("0 ");
DMEMIT("%u %u ", pg->nr_pgpaths,
pg->ps.type->info_args);
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT("%s %s %u ", p->path.dev->name,
p->is_active ? "A" : "F",
p->fail_count);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
&p->path, type, result + sz,
maxlen - sz);
}
}
break;
case STATUSTYPE_TABLE:
list_for_each_entry(pg, &m->priority_groups, list) {
DMEMIT("%s ", pg->ps.type->name);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps, NULL, type,
result + sz,
maxlen - sz);
else
DMEMIT("0 ");
DMEMIT("%u %u ", pg->nr_pgpaths,
pg->ps.type->table_args);
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT("%s ", p->path.dev->name);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
&p->path, type, result + sz,
maxlen - sz);
}
}
break;
}
spin_unlock_irqrestore(&m->lock, flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 523 | 80.09% | 3 | 27.27% |
| mike snitzer | mike snitzer | 60 | 9.19% | 4 | 36.36% |
| dave wysochanski | dave wysochanski | 38 | 5.82% | 1 | 9.09% |
| chandra seetharaman | chandra seetharaman | 31 | 4.75% | 2 | 18.18% |
| mikulas patocka | mikulas patocka | 1 | 0.15% | 1 | 9.09% |
| Total | 653 | 100.00% | 11 | 100.00% |
static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
{
int r = -EINVAL;
struct dm_dev *dev;
struct multipath *m = ti->private;
action_fn action;
mutex_lock(&m->work_mutex);
if (dm_suspended(ti)) {
r = -EBUSY;
goto out;
}
if (argc == 1) {
if (!strcasecmp(argv[0], "queue_if_no_path")) {
r = queue_if_no_path(m, true, false);
goto out;
} else if (!strcasecmp(argv[0], "fail_if_no_path")) {
r = queue_if_no_path(m, false, false);
goto out;
}
}
if (argc != 2) {
DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc);
goto out;
}
if (!strcasecmp(argv[0], "disable_group")) {
r = bypass_pg_num(m, argv[1], true);
goto out;
} else if (!strcasecmp(argv[0], "enable_group")) {
r = bypass_pg_num(m, argv[1], false);
goto out;
} else if (!strcasecmp(argv[0], "switch_group")) {
r = switch_pg_num(m, argv[1]);
goto out;
} else if (!strcasecmp(argv[0], "reinstate_path"))
action = reinstate_path;
else if (!strcasecmp(argv[0], "fail_path"))
action = fail_path;
else {
DMWARN("Unrecognised multipath message received: %s", argv[0]);
goto out;
}
r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
if (r) {
DMWARN("message: error getting device %s",
argv[1]);
goto out;
}
r = action_dev(m, dev, action);
dm_put_device(ti, dev);
out:
mutex_unlock(&m->work_mutex);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 258 | 69.35% | 3 | 37.50% |
| mike anderson | mike anderson | 75 | 20.16% | 1 | 12.50% |
| kiyoshi ueda | kiyoshi ueda | 17 | 4.57% | 1 | 12.50% |
| mike snitzer | mike snitzer | 13 | 3.49% | 2 | 25.00% |
| jose castillo | jose castillo | 9 | 2.42% | 1 | 12.50% |
| Total | 372 | 100.00% | 8 | 100.00% |
static int multipath_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev, fmode_t *mode)
{
struct multipath *m = ti->private;
struct pgpath *current_pgpath;
int r;
current_pgpath = lockless_dereference(m->current_pgpath);
if (!current_pgpath)
current_pgpath = choose_pgpath(m, 0);
if (current_pgpath) {
if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) {
*bdev = current_pgpath->path.dev->bdev;
*mode = current_pgpath->path.dev->mode;
r = 0;
} else {
/* pg_init has not started or completed */
r = -ENOTCONN;
}
} else {
/* No path is available */
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
r = -ENOTCONN;
else
r = -EIO;
}
if (r == -ENOTCONN) {
if (!lockless_dereference(m->current_pg)) {
/* Path status changed, redo selection */
(void) choose_pgpath(m, 0);
}
if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
pg_init_all_paths(m);
dm_table_run_md_queue_async(m->ti->table);
}
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (!r && ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT)
return 1;
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| milan broz | milan broz | 77 | 33.48% | 2 | 15.38% |
| mike snitzer | mike snitzer | 44 | 19.13% | 3 | 23.08% |
| hannes reinecke | hannes reinecke | 38 | 16.52% | 3 | 23.08% |
| christoph hellwig | christoph hellwig | 34 | 14.78% | 1 | 7.69% |
| jun'ichi nomura | jun'ichi nomura | 28 | 12.17% | 1 | 7.69% |
| mikulas patocka | mikulas patocka | 6 | 2.61% | 1 | 7.69% |
| kiyoshi ueda | kiyoshi ueda | 2 | 0.87% | 1 | 7.69% |
| al viro | al viro | 1 | 0.43% | 1 | 7.69% |
| Total | 230 | 100.00% | 13 | 100.00% |
static int multipath_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *p;
int ret = 0;
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(p, &pg->pgpaths, list) {
ret = fn(ti, p->path.dev, ti->begin, ti->len, data);
if (ret)
goto out;
}
}
out:
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mike snitzer | mike snitzer | 97 | 100.00% | 2 | 100.00% |
| Total | 97 | 100.00% | 2 | 100.00% |
static int pgpath_busy(struct pgpath *pgpath)
{
struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
return blk_lld_busy(q);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 31 | 93.94% | 1 | 33.33% |
| mike snitzer | mike snitzer | 2 | 6.06% | 2 | 66.67% |
| Total | 33 | 100.00% | 3 | 100.00% |
/*
* We return "busy", only when we can map I/Os but underlying devices
* are busy (so even if we map I/Os now, the I/Os will wait on
* the underlying queue).
* In other words, if we want to kill I/Os or queue them inside us
* due to map unavailability, we don't return "busy". Otherwise,
* dm core won't give us the I/Os and we can't do what we want.
*/
static int multipath_busy(struct dm_target *ti)
{
bool busy = false, has_active = false;
struct multipath *m = ti->private;
struct priority_group *pg, *next_pg;
struct pgpath *pgpath;
/* pg_init in progress or no paths available */
if (atomic_read(&m->pg_init_in_progress) ||
(!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)))
return true;
/* Guess which priority_group will be used at next mapping time */
pg = lockless_dereference(m->current_pg);
next_pg = lockless_dereference(m->next_pg);
if (unlikely(!lockless_dereference(m->current_pgpath) && next_pg))
pg = next_pg;
if (!pg) {
/*
* We don't know which pg will be used at next mapping time.
* We don't call choose_pgpath() here to avoid to trigger
* pg_init just by busy checking.
* So we don't know whether underlying devices we will be using
* at next mapping time are busy or not. Just try mapping.
*/
return busy;
}
/*
* If there is one non-busy active path at least, the path selector
* will be able to select it. So we consider such a pg as not busy.
*/
busy = true;
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->is_active) {
has_active = true;
if (!pgpath_busy(pgpath)) {
busy = false;
break;
}
}
}
if (!has_active) {
/*
* No active path in this pg, so this pg won't be used and
* the current_pg will be changed at next mapping time.
* We need to try mapping to determine it.
*/
busy = false;
}
return busy;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| kiyoshi ueda | kiyoshi ueda | 104 | 56.83% | 1 | 11.11% |
| mike snitzer | mike snitzer | 62 | 33.88% | 5 | 55.56% |
| jun'ichi nomura | jun'ichi nomura | 12 | 6.56% | 1 | 11.11% |
| hannes reinecke | hannes reinecke | 5 | 2.73% | 2 | 22.22% |
| Total | 183 | 100.00% | 9 | 100.00% |
/*-----------------------------------------------------------------
* Module setup
*---------------------------------------------------------------*/
static struct target_type multipath_target = {
.name = "multipath",
.version = {1, 11, 0},
.features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
.map_rq = multipath_map,
.clone_and_map_rq = multipath_clone_and_map,
.release_clone_rq = multipath_release_clone,
.rq_end_io = multipath_end_io,
.presuspend = multipath_presuspend,
.postsuspend = multipath_postsuspend,
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
.prepare_ioctl = multipath_prepare_ioctl,
.iterate_devices = multipath_iterate_devices,
.busy = multipath_busy,
};
static int __init dm_multipath_init(void)
{
int r;
/* allocate a slab for the dm_ios */
_mpio_cache = KMEM_CACHE(dm_mpath_io, 0);
if (!_mpio_cache)
return -ENOMEM;
r = dm_register_target(&multipath_target);
if (r < 0) {
DMERR("register failed %d", r);
r = -EINVAL;
goto bad_register_target;
}
kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0);
if (!kmultipathd) {
DMERR("failed to create workqueue kmpathd");
r = -ENOMEM;
goto bad_alloc_kmultipathd;
}
/*
* A separate workqueue is used to handle the device handlers
* to avoid overloading existing workqueue. Overloading the
* old workqueue would also create a bottleneck in the
* path of the storage hardware device activation.
*/
kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd",
WQ_MEM_RECLAIM);
if (!kmpath_handlerd) {
DMERR("failed to create workqueue kmpath_handlerd");
r = -ENOMEM;
goto bad_alloc_kmpath_handlerd;
}
DMINFO("version %u.%u.%u loaded",
multipath_target.version[0], multipath_target.version[1],
multipath_target.version[2]);
return 0;
bad_alloc_kmpath_handlerd:
destroy_workqueue(kmultipathd);
bad_alloc_kmultipathd:
dm_unregister_target(&multipath_target);
bad_register_target:
kmem_cache_destroy(_mpio_cache);
return r;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 105 | 59.32% | 5 | 62.50% |
| johannes thumshirn | johannes thumshirn | 43 | 24.29% | 1 | 12.50% |
| chandra seetharaman | chandra seetharaman | 21 | 11.86% | 1 | 12.50% |
| tejun heo | tejun heo | 8 | 4.52% | 1 | 12.50% |
| Total | 177 | 100.00% | 8 | 100.00% |
static void __exit dm_multipath_exit(void)
{
destroy_workqueue(kmpath_handlerd);
destroy_workqueue(kmultipathd);
dm_unregister_target(&multipath_target);
kmem_cache_destroy(_mpio_cache);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 25 | 83.33% | 2 | 66.67% |
| chandra seetharaman | chandra seetharaman | 5 | 16.67% | 1 | 33.33% |
| Total | 30 | 100.00% | 3 | 100.00% |
module_init(dm_multipath_init);
module_exit(dm_multipath_exit);
MODULE_DESCRIPTION(DM_NAME " multipath target");
MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alasdair kergon | alasdair kergon | 3871 | 48.30% | 16 | 13.68% |
| mike snitzer | mike snitzer | 1649 | 20.57% | 30 | 25.64% |
| chandra seetharaman | chandra seetharaman | 731 | 9.12% | 8 | 6.84% |
| kiyoshi ueda | kiyoshi ueda | 511 | 6.38% | 8 | 6.84% |
| hannes reinecke | hannes reinecke | 308 | 3.84% | 13 | 11.11% |
| dave wysochanski | dave wysochanski | 190 | 2.37% | 1 | 0.85% |
| mike anderson | mike anderson | 161 | 2.01% | 3 | 2.56% |
| jun'ichi nomura | jun'ichi nomura | 157 | 1.96% | 4 | 3.42% |
| milan broz | milan broz | 80 | 1.00% | 2 | 1.71% |
| christoph hellwig | christoph hellwig | 61 | 0.76% | 2 | 1.71% |
| benjamin marzinski | benjamin marzinski | 53 | 0.66% | 2 | 1.71% |
| michal miroslaw | michal miroslaw | 49 | 0.61% | 2 | 1.71% |
| mikulas patocka | mikulas patocka | 46 | 0.57% | 8 | 6.84% |
| johannes thumshirn | johannes thumshirn | 43 | 0.54% | 1 | 0.85% |
| shiva krishna merla | shiva krishna merla | 21 | 0.26% | 1 | 0.85% |
| keith busch | keith busch | 16 | 0.20% | 1 | 0.85% |
| tejun heo | tejun heo | 15 | 0.19% | 3 | 2.56% |
| david howells | david howells | 13 | 0.16% | 1 | 0.85% |
| mike christie | mike christie | 11 | 0.14% | 1 | 0.85% |
| jose castillo | jose castillo | 9 | 0.11% | 1 | 0.85% |
| wei yongjun | wei yongjun | 6 | 0.07% | 1 | 0.85% |
| babu moger | babu moger | 5 | 0.06% | 2 | 1.71% |
| lars marowsky-bree | lars marowsky-bree | 2 | 0.02% | 1 | 0.85% |
| christoph lameter | christoph lameter | 2 | 0.02% | 1 | 0.85% |
| josef 'jeff' sipek | josef 'jeff' sipek | 2 | 0.02% | 1 | 0.85% |
| al viro | al viro | 1 | 0.01% | 1 | 0.85% |
| arun sharma | arun sharma | 1 | 0.01% | 1 | 0.85% |
| matthew dobson | matthew dobson | 1 | 0.01% | 1 | 0.85% |
| Total | 8015 | 100.00% | 117 | 100.00% |
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