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| author |   Mike Snitzer <snitzer@redhat.com> | 2016-02-15 14:25:00 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-02-22 22:34:41 -0500 |
| commit | 9659f811446a67951127d4e81576204ffce9c86e (patch) | |
| tree | 115ce6ad350c9e431c0995130b57a67e43150f24 /drivers/md/dm-queue-length.c | |
| parent | dm mpath: remove repeat_count support from multipath core (diff) | |
| download | linux-dev-9659f811446a67951127d4e81576204ffce9c86e.tar.xz linux-dev-9659f811446a67951127d4e81576204ffce9c86e.zip | |
dm mpath: push path selector locking down to path selectors
Proper locking of the lists used by the path selectors should be handled
within the selectors (relying on dm-mpath.c code's use of the m->lock
spinlock was reckless).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-queue-length.c')
| -rw-r--r-- | drivers/md/dm-queue-length.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/md/dm-queue-length.c b/drivers/md/dm-queue-length.c index 51d82290ad4c..aeea3b7f3d5e 100644 --- a/drivers/md/dm-queue-length.c +++ b/drivers/md/dm-queue-length.c @@ -29,6 +29,7 @@ struct selector { struct list_head valid_paths; struct list_head failed_paths; + spinlock_t lock; }; struct path_info { @@ -45,6 +46,7 @@ static struct selector *alloc_selector(void) if (s) { INIT_LIST_HEAD(&s->valid_paths); INIT_LIST_HEAD(&s->failed_paths); + spin_lock_init(&s->lock); } return s; @@ -113,6 +115,7 @@ static int ql_add_path(struct path_selector *ps, struct dm_path *path, struct path_info *pi; unsigned repeat_count = QL_MIN_IO; char dummy; + unsigned long flags; /* * Arguments: [<repeat_count>] @@ -147,7 +150,9 @@ static int ql_add_path(struct path_selector *ps, struct dm_path *path, path->pscontext = pi; + spin_lock_irqsave(&s->lock, flags); list_add_tail(&pi->list, &s->valid_paths); + spin_unlock_irqrestore(&s->lock, flags); return 0; } @@ -156,16 +161,22 @@ static void ql_fail_path(struct path_selector *ps, struct dm_path *path) { struct selector *s = ps->context; struct path_info *pi = path->pscontext; + unsigned long flags; + spin_lock_irqsave(&s->lock, flags); list_move(&pi->list, &s->failed_paths); + spin_unlock_irqrestore(&s->lock, flags); } static int ql_reinstate_path(struct path_selector *ps, struct dm_path *path) { struct selector *s = ps->context; struct path_info *pi = path->pscontext; + unsigned long flags; + spin_lock_irqsave(&s->lock, flags); list_move_tail(&pi->list, &s->valid_paths); + spin_unlock_irqrestore(&s->lock, flags); return 0; } @@ -178,9 +189,12 @@ static struct dm_path *ql_select_path(struct path_selector *ps, { struct selector *s = ps->context; struct path_info *pi = NULL, *best = NULL; + struct dm_path *ret = NULL; + unsigned long flags; + spin_lock_irqsave(&s->lock, flags); if (list_empty(&s->valid_paths)) - return NULL; + goto out; /* Change preferred (first in list) path to evenly balance. */ list_move_tail(s->valid_paths.next, &s->valid_paths); @@ -195,11 +209,14 @@ static struct dm_path *ql_select_path(struct path_selector *ps, } if (!best) - return NULL; + goto out; *repeat_count = best->repeat_count; - return best->path; + ret = best->path; +out: + spin_unlock_irqrestore(&s->lock, flags); + return ret; } static int ql_start_io(struct path_selector *ps, struct dm_path *path, |