diff options
Diffstat (limited to 'drivers/staging/zram/zram_drv.c')
-rw-r--r-- | drivers/staging/zram/zram_drv.c | 96 |
1 files changed, 55 insertions, 41 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index d70ec1a..b9926ee 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -37,10 +37,10 @@ /* Globals */ static int zram_major; -struct zram *devices; +struct zram *zram_devices; /* Module params (documentation at end) */ -unsigned int num_devices; +unsigned int zram_num_devices; static void zram_stat_inc(u32 *v) { @@ -560,27 +560,34 @@ static int zram_make_request(struct request_queue *queue, struct bio *bio) { struct zram *zram = queue->queuedata; + if (unlikely(!zram->init_done) && zram_init_device(zram)) + goto error; + + down_read(&zram->init_lock); + if (unlikely(!zram->init_done)) + goto error_unlock; + if (!valid_io_request(zram, bio)) { zram_stat64_inc(zram, &zram->stats.invalid_io); - bio_io_error(bio); - return 0; - } - - if (unlikely(!zram->init_done) && zram_init_device(zram)) { - bio_io_error(bio); - return 0; + goto error_unlock; } __zram_make_request(zram, bio, bio_data_dir(bio)); + up_read(&zram->init_lock); return 0; + +error_unlock: + up_read(&zram->init_lock); +error: + bio_io_error(bio); + return 0; } -void zram_reset_device(struct zram *zram) +void __zram_reset_device(struct zram *zram) { size_t index; - mutex_lock(&zram->init_lock); zram->init_done = 0; /* Free various per-device buffers */ @@ -617,7 +624,13 @@ void zram_reset_device(struct zram *zram) memset(&zram->stats, 0, sizeof(zram->stats)); zram->disksize = 0; - mutex_unlock(&zram->init_lock); +} + +void zram_reset_device(struct zram *zram) +{ + down_write(&zram->init_lock); + __zram_reset_device(zram); + up_write(&zram->init_lock); } int zram_init_device(struct zram *zram) @@ -625,10 +638,10 @@ int zram_init_device(struct zram *zram) int ret; size_t num_pages; - mutex_lock(&zram->init_lock); + down_write(&zram->init_lock); if (zram->init_done) { - mutex_unlock(&zram->init_lock); + up_write(&zram->init_lock); return 0; } @@ -638,24 +651,22 @@ int zram_init_device(struct zram *zram) if (!zram->compress_workmem) { pr_err("Error allocating compressor working memory!\n"); ret = -ENOMEM; - goto fail; + goto fail_no_table; } zram->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1); if (!zram->compress_buffer) { pr_err("Error allocating compressor buffer space\n"); ret = -ENOMEM; - goto fail; + goto fail_no_table; } num_pages = zram->disksize >> PAGE_SHIFT; zram->table = vzalloc(num_pages * sizeof(*zram->table)); if (!zram->table) { pr_err("Error allocating zram address table\n"); - /* To prevent accessing table entries during cleanup */ - zram->disksize = 0; ret = -ENOMEM; - goto fail; + goto fail_no_table; } set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); @@ -671,20 +682,23 @@ int zram_init_device(struct zram *zram) } zram->init_done = 1; - mutex_unlock(&zram->init_lock); + up_write(&zram->init_lock); pr_debug("Initialization done!\n"); return 0; +fail_no_table: + /* To prevent accessing table entries during cleanup */ + zram->disksize = 0; fail: - mutex_unlock(&zram->init_lock); - zram_reset_device(zram); - + __zram_reset_device(zram); + up_write(&zram->init_lock); pr_err("Initialization failed: err=%d\n", ret); return ret; } -void zram_slot_free_notify(struct block_device *bdev, unsigned long index) +static void zram_slot_free_notify(struct block_device *bdev, + unsigned long index) { struct zram *zram; @@ -703,7 +717,7 @@ static int create_device(struct zram *zram, int device_id) int ret = 0; init_rwsem(&zram->lock); - mutex_init(&zram->init_lock); + init_rwsem(&zram->init_lock); spin_lock_init(&zram->stat64_lock); zram->queue = blk_alloc_queue(GFP_KERNEL); @@ -780,9 +794,9 @@ static int __init zram_init(void) { int ret, dev_id; - if (num_devices > max_num_devices) { + if (zram_num_devices > max_num_devices) { pr_warning("Invalid value for num_devices: %u\n", - num_devices); + zram_num_devices); ret = -EINVAL; goto out; } @@ -794,21 +808,21 @@ static int __init zram_init(void) goto out; } - if (!num_devices) { + if (!zram_num_devices) { pr_info("num_devices not specified. Using default: 1\n"); - num_devices = 1; + zram_num_devices = 1; } /* Allocate the device array and initialize each one */ - pr_info("Creating %u devices ...\n", num_devices); - devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL); - if (!devices) { + pr_info("Creating %u devices ...\n", zram_num_devices); + zram_devices = kzalloc(zram_num_devices * sizeof(struct zram), GFP_KERNEL); + if (!zram_devices) { ret = -ENOMEM; goto unregister; } - for (dev_id = 0; dev_id < num_devices; dev_id++) { - ret = create_device(&devices[dev_id], dev_id); + for (dev_id = 0; dev_id < zram_num_devices; dev_id++) { + ret = create_device(&zram_devices[dev_id], dev_id); if (ret) goto free_devices; } @@ -817,8 +831,8 @@ static int __init zram_init(void) free_devices: while (dev_id) - destroy_device(&devices[--dev_id]); - kfree(devices); + destroy_device(&zram_devices[--dev_id]); + kfree(zram_devices); unregister: unregister_blkdev(zram_major, "zram"); out: @@ -830,8 +844,8 @@ static void __exit zram_exit(void) int i; struct zram *zram; - for (i = 0; i < num_devices; i++) { - zram = &devices[i]; + for (i = 0; i < zram_num_devices; i++) { + zram = &zram_devices[i]; destroy_device(zram); if (zram->init_done) @@ -840,12 +854,12 @@ static void __exit zram_exit(void) unregister_blkdev(zram_major, "zram"); - kfree(devices); + kfree(zram_devices); pr_debug("Cleanup done!\n"); } -module_param(num_devices, uint, 0); -MODULE_PARM_DESC(num_devices, "Number of zram devices"); +module_param(zram_num_devices, uint, 0); +MODULE_PARM_DESC(zram_num_devices, "Number of zram devices"); module_init(zram_init); module_exit(zram_exit); |