diff options
Diffstat (limited to 'drivers/block/xen-blkfront.c')
| -rw-r--r-- | drivers/block/xen-blkfront.c | 110 |
1 files changed, 98 insertions, 12 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 8986adab9bf5..429d20131c7e 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -46,6 +46,7 @@ #include <linux/scatterlist.h> #include <linux/bitmap.h> #include <linux/list.h> +#include <linux/workqueue.h> #include <xen/xen.h> #include <xen/xenbus.h> @@ -121,6 +122,8 @@ static inline struct blkif_req *blkif_req(struct request *rq) static DEFINE_MUTEX(blkfront_mutex); static const struct block_device_operations xlvbd_block_fops; +static struct delayed_work blkfront_work; +static LIST_HEAD(info_list); /* * Maximum number of segments in indirect requests, the actual value used by @@ -216,6 +219,7 @@ struct blkfront_info /* Save uncomplete reqs and bios for migration. */ struct list_head requests; struct bio_list bio_list; + struct list_head info_list; }; static unsigned int nr_minors; @@ -1759,6 +1763,12 @@ abort_transaction: return err; } +static void free_info(struct blkfront_info *info) +{ + list_del(&info->info_list); + kfree(info); +} + /* Common code used when first setting up, and when resuming. */ static int talk_to_blkback(struct xenbus_device *dev, struct blkfront_info *info) @@ -1880,7 +1890,10 @@ again: destroy_blkring: blkif_free(info, 0); - kfree(info); + mutex_lock(&blkfront_mutex); + free_info(info); + mutex_unlock(&blkfront_mutex); + dev_set_drvdata(&dev->dev, NULL); return err; @@ -1991,6 +2004,10 @@ static int blkfront_probe(struct xenbus_device *dev, info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); dev_set_drvdata(&dev->dev, info); + mutex_lock(&blkfront_mutex); + list_add(&info->info_list, &info_list); + mutex_unlock(&blkfront_mutex); + return 0; } @@ -2301,6 +2318,12 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) if (indirect_segments <= BLKIF_MAX_SEGMENTS_PER_REQUEST) indirect_segments = 0; info->max_indirect_segments = indirect_segments; + + if (info->feature_persistent) { + mutex_lock(&blkfront_mutex); + schedule_delayed_work(&blkfront_work, HZ * 10); + mutex_unlock(&blkfront_mutex); + } } /* @@ -2482,7 +2505,9 @@ static int blkfront_remove(struct xenbus_device *xbdev) mutex_unlock(&info->mutex); if (!bdev) { - kfree(info); + mutex_lock(&blkfront_mutex); + free_info(info); + mutex_unlock(&blkfront_mutex); return 0; } @@ -2502,7 +2527,9 @@ static int blkfront_remove(struct xenbus_device *xbdev) if (info && !bdev->bd_openers) { xlvbd_release_gendisk(info); disk->private_data = NULL; - kfree(info); + mutex_lock(&blkfront_mutex); + free_info(info); + mutex_unlock(&blkfront_mutex); } mutex_unlock(&bdev->bd_mutex); @@ -2585,7 +2612,7 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); xlvbd_release_gendisk(info); disk->private_data = NULL; - kfree(info); + free_info(info); } out: @@ -2618,6 +2645,61 @@ static struct xenbus_driver blkfront_driver = { .is_ready = blkfront_is_ready, }; +static void purge_persistent_grants(struct blkfront_info *info) +{ + unsigned int i; + unsigned long flags; + + for (i = 0; i < info->nr_rings; i++) { + struct blkfront_ring_info *rinfo = &info->rinfo[i]; + struct grant *gnt_list_entry, *tmp; + + spin_lock_irqsave(&rinfo->ring_lock, flags); + + if (rinfo->persistent_gnts_c == 0) { + spin_unlock_irqrestore(&rinfo->ring_lock, flags); + continue; + } + + list_for_each_entry_safe(gnt_list_entry, tmp, &rinfo->grants, + node) { + if (gnt_list_entry->gref == GRANT_INVALID_REF || + gnttab_query_foreign_access(gnt_list_entry->gref)) + continue; + + list_del(&gnt_list_entry->node); + gnttab_end_foreign_access(gnt_list_entry->gref, 0, 0UL); + rinfo->persistent_gnts_c--; + gnt_list_entry->gref = GRANT_INVALID_REF; + list_add_tail(&gnt_list_entry->node, &rinfo->grants); + } + + spin_unlock_irqrestore(&rinfo->ring_lock, flags); + } +} + +static void blkfront_delay_work(struct work_struct *work) +{ + struct blkfront_info *info; + bool need_schedule_work = false; + + mutex_lock(&blkfront_mutex); + + list_for_each_entry(info, &info_list, info_list) { + if (info->feature_persistent) { + need_schedule_work = true; + mutex_lock(&info->mutex); + purge_persistent_grants(info); + mutex_unlock(&info->mutex); + } + } + + if (need_schedule_work) + schedule_delayed_work(&blkfront_work, HZ * 10); + + mutex_unlock(&blkfront_mutex); +} + static int __init xlblk_init(void) { int ret; @@ -2626,6 +2708,15 @@ static int __init xlblk_init(void) if (!xen_domain()) return -ENODEV; + if (!xen_has_pv_disk_devices()) + return -ENODEV; + + if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { + pr_warn("xen_blk: can't get major %d with name %s\n", + XENVBD_MAJOR, DEV_NAME); + return -ENODEV; + } + if (xen_blkif_max_segments < BLKIF_MAX_SEGMENTS_PER_REQUEST) xen_blkif_max_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST; @@ -2641,14 +2732,7 @@ static int __init xlblk_init(void) xen_blkif_max_queues = nr_cpus; } - if (!xen_has_pv_disk_devices()) - return -ENODEV; - - if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { - printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", - XENVBD_MAJOR, DEV_NAME); - return -ENODEV; - } + INIT_DELAYED_WORK(&blkfront_work, blkfront_delay_work); ret = xenbus_register_frontend(&blkfront_driver); if (ret) { @@ -2663,6 +2747,8 @@ module_init(xlblk_init); static void __exit xlblk_exit(void) { + cancel_delayed_work_sync(&blkfront_work); + xenbus_unregister_driver(&blkfront_driver); unregister_blkdev(XENVBD_MAJOR, DEV_NAME); kfree(minors); |