diff options
| -rw-r--r-- | drivers/block/rbd.c | 69 |
1 files changed, 23 insertions, 46 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 8b78a08483a6..d250549d27a4 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -41,6 +41,7 @@ #include <linux/fs.h> #include <linux/blkdev.h> #include <linux/slab.h> +#include <linux/idr.h> #include "rbd_types.h" @@ -385,6 +386,8 @@ static struct kmem_cache *rbd_img_request_cache; static struct kmem_cache *rbd_obj_request_cache; static struct kmem_cache *rbd_segment_name_cache; +static DEFINE_IDA(rbd_dev_id_ida); + static int rbd_img_request_submit(struct rbd_img_request *img_request); static void rbd_dev_device_release(struct device *dev); @@ -4371,20 +4374,27 @@ static void rbd_bus_del_dev(struct rbd_device *rbd_dev) device_unregister(&rbd_dev->dev); } -static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0); - /* * Get a unique rbd identifier for the given new rbd_dev, and add - * the rbd_dev to the global list. The minimum rbd id is 1. + * the rbd_dev to the global list. */ -static void rbd_dev_id_get(struct rbd_device *rbd_dev) +static int rbd_dev_id_get(struct rbd_device *rbd_dev) { - rbd_dev->dev_id = atomic64_inc_return(&rbd_dev_id_max); + int new_dev_id; + + new_dev_id = ida_simple_get(&rbd_dev_id_ida, 0, 0, GFP_KERNEL); + if (new_dev_id < 0) + return new_dev_id; + + rbd_dev->dev_id = new_dev_id; spin_lock(&rbd_dev_list_lock); list_add_tail(&rbd_dev->node, &rbd_dev_list); spin_unlock(&rbd_dev_list_lock); + dout("rbd_dev %p given dev id %d\n", rbd_dev, rbd_dev->dev_id); + + return 0; } /* @@ -4393,48 +4403,13 @@ static void rbd_dev_id_get(struct rbd_device *rbd_dev) */ static void rbd_dev_id_put(struct rbd_device *rbd_dev) { - struct list_head *tmp; - int rbd_id = rbd_dev->dev_id; - int max_id; - - rbd_assert(rbd_id > 0); - - dout("rbd_dev %p released dev id %d\n", rbd_dev, rbd_dev->dev_id); spin_lock(&rbd_dev_list_lock); list_del_init(&rbd_dev->node); - - /* - * If the id being "put" is not the current maximum, there - * is nothing special we need to do. - */ - if (rbd_id != atomic64_read(&rbd_dev_id_max)) { - spin_unlock(&rbd_dev_list_lock); - return; - } - - /* - * We need to update the current maximum id. Search the - * list to find out what it is. We're more likely to find - * the maximum at the end, so search the list backward. - */ - max_id = 0; - list_for_each_prev(tmp, &rbd_dev_list) { - struct rbd_device *rbd_dev; - - rbd_dev = list_entry(tmp, struct rbd_device, node); - if (rbd_dev->dev_id > max_id) - max_id = rbd_dev->dev_id; - } spin_unlock(&rbd_dev_list_lock); - /* - * The max id could have been updated by rbd_dev_id_get(), in - * which case it now accurately reflects the new maximum. - * Be careful not to overwrite the maximum value in that - * case. - */ - atomic64_cmpxchg(&rbd_dev_id_max, rbd_id, max_id); - dout(" max dev id has been reset\n"); + ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id); + + dout("rbd_dev %p released dev id %d\n", rbd_dev, rbd_dev->dev_id); } /* @@ -4857,10 +4832,12 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev) { int ret; - /* generate unique id: find highest unique id, add one */ - rbd_dev_id_get(rbd_dev); + /* Get an id and fill in device name. */ + + ret = rbd_dev_id_get(rbd_dev); + if (ret) + return ret; - /* Fill in the device name, now that we have its id. */ BUILD_BUG_ON(DEV_NAME_LEN < sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH); sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id); |