diff options
| -rw-r--r-- | drivers/block/ll_rw_blk.c | 18 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
2 files changed, 16 insertions, 3 deletions
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c index 692a5fced76..3c818544475 100644 --- a/drivers/block/ll_rw_blk.c +++ b/drivers/block/ll_rw_blk.c @@ -719,7 +719,7 @@ struct request *blk_queue_find_tag(request_queue_t *q, int tag) { struct blk_queue_tag *bqt = q->queue_tags; - if (unlikely(bqt == NULL || tag >= bqt->max_depth)) + if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) return NULL; return bqt->tag_index[tag]; @@ -798,6 +798,7 @@ init_tag_map(request_queue_t *q, struct blk_queue_tag *tags, int depth) memset(tag_index, 0, depth * sizeof(struct request *)); memset(tag_map, 0, nr_ulongs * sizeof(unsigned long)); + tags->real_max_depth = depth; tags->max_depth = depth; tags->tag_index = tag_index; tags->tag_map = tag_map; @@ -872,11 +873,22 @@ int blk_queue_resize_tags(request_queue_t *q, int new_depth) return -ENXIO; /* + * if we already have large enough real_max_depth. just + * adjust max_depth. *NOTE* as requests with tag value + * between new_depth and real_max_depth can be in-flight, tag + * map can not be shrunk blindly here. + */ + if (new_depth <= bqt->real_max_depth) { + bqt->max_depth = new_depth; + return 0; + } + + /* * save the old state info, so we can copy it back */ tag_index = bqt->tag_index; tag_map = bqt->tag_map; - max_depth = bqt->max_depth; + max_depth = bqt->real_max_depth; if (init_tag_map(q, bqt, new_depth)) return -ENOMEM; @@ -913,7 +925,7 @@ void blk_queue_end_tag(request_queue_t *q, struct request *rq) BUG_ON(tag == -1); - if (unlikely(tag >= bqt->max_depth)) + if (unlikely(tag >= bqt->real_max_depth)) /* * This can happen after tag depth has been reduced. * FIXME: how about a warning or info message here? diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0881b5cdee3..19bd8e7e11b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -301,6 +301,7 @@ struct blk_queue_tag { struct list_head busy_list; /* fifo list of busy tags */ int busy; /* current depth */ int max_depth; /* what we will send to device */ + int real_max_depth; /* what the array can hold */ atomic_t refcnt; /* map can be shared */ }; |