diff options
Diffstat (limited to 'drivers/staging/zram')
-rw-r--r-- | drivers/staging/zram/zram_drv.c | 97 | ||||
-rw-r--r-- | drivers/staging/zram/zram_drv.h | 12 | ||||
-rw-r--r-- | drivers/staging/zram/zram_sysfs.c | 22 |
3 files changed, 76 insertions, 55 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index 02589ca..09de99f 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) { @@ -560,25 +560,33 @@ static void 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; - } - - if (unlikely(!zram->init_done) && zram_init_device(zram)) { - bio_io_error(bio); - return; + goto error_unlock; } __zram_make_request(zram, bio, bio_data_dir(bio)); + up_read(&zram->init_lock); + + return; + +error_unlock: + up_read(&zram->init_lock); +error: + bio_io_error(bio); } -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 */ @@ -615,7 +623,13 @@ 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) @@ -623,10 +637,10 @@ 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; } @@ -636,24 +650,22 @@ 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); @@ -669,20 +681,23 @@ 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; @@ -701,7 +716,7 @@ 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); @@ -778,9 +793,9 @@ 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; } @@ -792,21 +807,21 @@ 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; } @@ -815,8 +830,8 @@ 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: @@ -828,8 +843,8 @@ 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) @@ -838,12 +853,12 @@ 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); diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index abe5221..e5cd246 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -47,7 +47,7 @@ static const unsigned default_disksize_perc_ram = 25; * Pages that compress to size greater than this are stored * uncompressed in memory. */ -static const unsigned max_zpage_size = PAGE_SIZE / 4 * 3; +static const size_t max_zpage_size = PAGE_SIZE / 4 * 3; /* * NOTE: max_zpage_size must be less than or equal to: @@ -112,8 +112,8 @@ struct zram { struct request_queue *queue; struct gendisk *disk; int init_done; - /* Prevent concurrent execution of device init and reset */ - struct mutex init_lock; + /* Prevent concurrent execution of device init, reset and R/W request */ + struct rw_semaphore init_lock; /* * This is the limit on amount of *uncompressed* worth of data * we can store in a disk. @@ -123,13 +123,13 @@ struct zram { struct zram_stats stats; }; -extern struct zram *devices; -extern unsigned int num_devices; +extern struct zram *zram_devices; +extern unsigned int zram_num_devices; #ifdef CONFIG_SYSFS extern struct attribute_group zram_disk_attr_group; #endif extern int zram_init_device(struct zram *zram); -extern void zram_reset_device(struct zram *zram); +extern void __zram_reset_device(struct zram *zram); #endif diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index a70cc01..0ea8ed2 100644 --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -34,8 +34,8 @@ static struct zram *dev_to_zram(struct device *dev) int i; struct zram *zram = NULL; - for (i = 0; i < num_devices; i++) { - zram = &devices[i]; + for (i = 0; i < zram_num_devices; i++) { + zram = &zram_devices[i]; if (disk_to_dev(zram->disk) == dev) break; } @@ -55,19 +55,23 @@ static ssize_t disksize_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int ret; + u64 disksize; struct zram *zram = dev_to_zram(dev); + ret = strict_strtoull(buf, 10, &disksize); + if (ret) + return ret; + + down_write(&zram->init_lock); if (zram->init_done) { + up_write(&zram->init_lock); pr_info("Cannot change disksize for initialized device\n"); return -EBUSY; } - ret = strict_strtoull(buf, 10, &zram->disksize); - if (ret) - return ret; - - zram->disksize = PAGE_ALIGN(zram->disksize); + zram->disksize = PAGE_ALIGN(disksize); set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + up_write(&zram->init_lock); return len; } @@ -106,8 +110,10 @@ static ssize_t reset_store(struct device *dev, if (bdev) fsync_bdev(bdev); + down_write(&zram->init_lock); if (zram->init_done) - zram_reset_device(zram); + __zram_reset_device(zram); + up_write(&zram->init_lock); return len; } |