diff options
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, |