diff options
Diffstat (limited to 'drivers/staging/zram/zram_drv.c')
-rw-r--r-- | drivers/staging/zram/zram_drv.c | 569 |
1 files changed, 371 insertions, 198 deletions
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index e34e3fe0ae2e..82c7202fd5cc 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -37,28 +37,107 @@ /* Globals */ static int zram_major; -struct zram *zram_devices; +static struct zram *zram_devices; /* Module params (documentation at end) */ static unsigned int num_devices = 1; -static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) +static inline struct zram *dev_to_zram(struct device *dev) { - spin_lock(&zram->stat64_lock); - *v = *v + inc; - spin_unlock(&zram->stat64_lock); + return (struct zram *)dev_to_disk(dev)->private_data; } -static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) +static ssize_t disksize_show(struct device *dev, + struct device_attribute *attr, char *buf) { - spin_lock(&zram->stat64_lock); - *v = *v - dec; - spin_unlock(&zram->stat64_lock); + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", zram->disksize); +} + +static ssize_t initstate_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->init_done); +} + +static ssize_t num_reads_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)atomic64_read(&zram->stats.num_reads)); +} + +static ssize_t num_writes_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)atomic64_read(&zram->stats.num_writes)); +} + +static ssize_t invalid_io_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)atomic64_read(&zram->stats.invalid_io)); +} + +static ssize_t notify_free_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)atomic64_read(&zram->stats.notify_free)); } -static void zram_stat64_inc(struct zram *zram, u64 *v) +static ssize_t zero_pages_show(struct device *dev, + struct device_attribute *attr, char *buf) { - zram_stat64_add(zram, v, 1); + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%u\n", zram->stats.pages_zero); +} + +static ssize_t orig_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)(zram->stats.pages_stored) << PAGE_SHIFT); +} + +static ssize_t compr_data_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + + return sprintf(buf, "%llu\n", + (u64)atomic64_read(&zram->stats.compr_size)); +} + +static ssize_t mem_used_total_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + u64 val = 0; + struct zram *zram = dev_to_zram(dev); + struct zram_meta *meta = zram->meta; + + down_read(&zram->init_lock); + if (zram->init_done) + val = zs_get_total_size_bytes(meta->mem_pool); + up_read(&zram->init_lock); + + return sprintf(buf, "%llu\n", val); } static int zram_test_flag(struct zram_meta *meta, u32 index, @@ -79,6 +158,97 @@ static void zram_clear_flag(struct zram_meta *meta, u32 index, meta->table[index].flags &= ~BIT(flag); } +static inline int is_partial_io(struct bio_vec *bvec) +{ + return bvec->bv_len != PAGE_SIZE; +} + +/* + * Check if request is within bounds and aligned on zram logical blocks. + */ +static inline int valid_io_request(struct zram *zram, struct bio *bio) +{ + u64 start, end, bound; + + /* unaligned request */ + if (unlikely(bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1))) + return 0; + if (unlikely(bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1))) + return 0; + + start = bio->bi_sector; + end = start + (bio->bi_size >> SECTOR_SHIFT); + bound = zram->disksize >> SECTOR_SHIFT; + /* out of range range */ + if (unlikely(start >= bound || end > bound || start > end)) + return 0; + + /* I/O request is valid */ + return 1; +} + +static void zram_meta_free(struct zram_meta *meta) +{ + zs_destroy_pool(meta->mem_pool); + kfree(meta->compress_workmem); + free_pages((unsigned long)meta->compress_buffer, 1); + vfree(meta->table); + kfree(meta); +} + +static struct zram_meta *zram_meta_alloc(u64 disksize) +{ + size_t num_pages; + struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); + if (!meta) + goto out; + + meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!meta->compress_workmem) + goto free_meta; + + meta->compress_buffer = + (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); + if (!meta->compress_buffer) { + pr_err("Error allocating compressor buffer space\n"); + goto free_workmem; + } + + num_pages = disksize >> PAGE_SHIFT; + meta->table = vzalloc(num_pages * sizeof(*meta->table)); + if (!meta->table) { + pr_err("Error allocating zram address table\n"); + goto free_buffer; + } + + meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM); + if (!meta->mem_pool) { + pr_err("Error creating memory pool\n"); + goto free_table; + } + + return meta; + +free_table: + vfree(meta->table); +free_buffer: + free_pages((unsigned long)meta->compress_buffer, 1); +free_workmem: + kfree(meta->compress_workmem); +free_meta: + kfree(meta); + meta = NULL; +out: + return meta; +} + +static void update_position(u32 *index, int *offset, struct bio_vec *bvec) +{ + if (*offset + bvec->bv_len >= PAGE_SIZE) + (*index)++; + *offset = (*offset + bvec->bv_len) % PAGE_SIZE; +} + static int page_zero_filled(void *ptr) { unsigned int pos; @@ -94,6 +264,21 @@ static int page_zero_filled(void *ptr) return 1; } +static void handle_zero_page(struct bio_vec *bvec) +{ + struct page *page = bvec->bv_page; + void *user_mem; + + user_mem = kmap_atomic(page); + if (is_partial_io(bvec)) + memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); + else + clear_page(user_mem); + kunmap_atomic(user_mem); + + flush_dcache_page(page); +} + static void zram_free_page(struct zram *zram, size_t index) { struct zram_meta *meta = zram->meta; @@ -120,31 +305,13 @@ static void zram_free_page(struct zram *zram, size_t index) if (size <= PAGE_SIZE / 2) zram->stats.good_compress--; - zram_stat64_sub(zram, &zram->stats.compr_size, - meta->table[index].size); + atomic64_sub(meta->table[index].size, &zram->stats.compr_size); zram->stats.pages_stored--; meta->table[index].handle = 0; meta->table[index].size = 0; } -static void handle_zero_page(struct bio_vec *bvec) -{ - struct page *page = bvec->bv_page; - void *user_mem; - - user_mem = kmap_atomic(page); - memset(user_mem + bvec->bv_offset, 0, bvec->bv_len); - kunmap_atomic(user_mem); - - flush_dcache_page(page); -} - -static inline int is_partial_io(struct bio_vec *bvec) -{ - return bvec->bv_len != PAGE_SIZE; -} - static int zram_decompress_page(struct zram *zram, char *mem, u32 index) { int ret = LZO_E_OK; @@ -154,13 +321,13 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index) unsigned long handle = meta->table[index].handle; if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { - memset(mem, 0, PAGE_SIZE); + clear_page(mem); return 0; } cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); if (meta->table[index].size == PAGE_SIZE) - memcpy(mem, cmem, PAGE_SIZE); + copy_page(mem, cmem); else ret = lzo1x_decompress_safe(cmem, meta->table[index].size, mem, &clen); @@ -169,7 +336,7 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index) /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); + atomic64_inc(&zram->stats.failed_reads); return ret; } @@ -272,8 +439,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, if (page_zero_filled(uncmem)) { kunmap_atomic(user_mem); - if (is_partial_io(bvec)) - kfree(uncmem); zram->stats.pages_zero++; zram_set_flag(meta, index, ZRAM_ZERO); ret = 0; @@ -304,18 +469,20 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, handle = zs_malloc(meta->mem_pool, clen); if (!handle) { - pr_info("Error allocating memory for compressed " - "page: %u, size=%zu\n", index, clen); + pr_info("Error allocating memory for compressed page: %u, size=%zu\n", + index, clen); ret = -ENOMEM; goto out; } cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); - if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) + if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) { src = kmap_atomic(page); - memcpy(cmem, src, clen); - if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) + copy_page(cmem, src); kunmap_atomic(src); + } else { + memcpy(cmem, src, clen); + } zs_unmap_object(meta->mem_pool, handle); @@ -323,7 +490,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, meta->table[index].size = clen; /* Update stats */ - zram_stat64_add(zram, &zram->stats.compr_size, clen); + atomic64_add(clen, &zram->stats.compr_size); zram->stats.pages_stored++; if (clen <= PAGE_SIZE / 2) zram->stats.good_compress++; @@ -333,7 +500,7 @@ out: kfree(uncmem); if (ret) - zram_stat64_inc(zram, &zram->stats.failed_writes); + atomic64_inc(&zram->stats.failed_writes); return ret; } @@ -355,11 +522,117 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, return ret; } -static void update_position(u32 *index, int *offset, struct bio_vec *bvec) +static void zram_reset_device(struct zram *zram) { - if (*offset + bvec->bv_len >= PAGE_SIZE) - (*index)++; - *offset = (*offset + bvec->bv_len) % PAGE_SIZE; + size_t index; + struct zram_meta *meta; + + if (!zram->init_done) + return; + + meta = zram->meta; + zram->init_done = 0; + + /* Free all pages that are still in this zram device */ + for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { + unsigned long handle = meta->table[index].handle; + if (!handle) + continue; + + zs_free(meta->mem_pool, handle); + } + + zram_meta_free(zram->meta); + zram->meta = NULL; + /* Reset stats */ + memset(&zram->stats, 0, sizeof(zram->stats)); + + zram->disksize = 0; + set_capacity(zram->disk, 0); +} + +static void zram_init_device(struct zram *zram, struct zram_meta *meta) +{ + if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) { + pr_info( + "There is little point creating a zram of greater than " + "twice the size of memory since we expect a 2:1 compression " + "ratio. Note that zram uses about 0.1%% of the size of " + "the disk when not in use so a huge zram is " + "wasteful.\n" + "\tMemory Size: %lu kB\n" + "\tSize you selected: %llu kB\n" + "Continuing anyway ...\n", + (totalram_pages << PAGE_SHIFT) >> 10, zram->disksize >> 10 + ); + } + + /* zram devices sort of resembles non-rotational disks */ + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); + + zram->meta = meta; + zram->init_done = 1; + + pr_debug("Initialization done!\n"); +} + +static ssize_t disksize_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + u64 disksize; + struct zram_meta *meta; + struct zram *zram = dev_to_zram(dev); + + disksize = memparse(buf, NULL); + if (!disksize) + return -EINVAL; + + disksize = PAGE_ALIGN(disksize); + meta = zram_meta_alloc(disksize); + down_write(&zram->init_lock); + if (zram->init_done) { + up_write(&zram->init_lock); + zram_meta_free(meta); + pr_info("Cannot change disksize for initialized device\n"); + return -EBUSY; + } + + zram->disksize = disksize; + set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); + zram_init_device(zram, meta); + up_write(&zram->init_lock); + + return len; +} + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + int ret; + unsigned short do_reset; + struct zram *zram; + struct block_device *bdev; + + zram = dev_to_zram(dev); + bdev = bdget_disk(zram->disk, 0); + + /* Do not reset an active device! */ + if (bdev->bd_holders) + return -EBUSY; + + ret = kstrtou16(buf, 10, &do_reset); + if (ret) + return ret; + + if (!do_reset) + return -EINVAL; + + /* Make sure all pending I/O is finished */ + if (bdev) + fsync_bdev(bdev); + + zram_reset_device(zram); + return len; } static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) @@ -370,10 +643,10 @@ static void __zram_make_request(struct zram *zram, struct bio *bio, int rw) switch (rw) { case READ: - zram_stat64_inc(zram, &zram->stats.num_reads); + atomic64_inc(&zram->stats.num_reads); break; case WRITE: - zram_stat64_inc(zram, &zram->stats.num_writes); + atomic64_inc(&zram->stats.num_writes); break; } @@ -418,23 +691,6 @@ out: } /* - * Check if request is within bounds and aligned on zram logical blocks. - */ -static inline int valid_io_request(struct zram *zram, struct bio *bio) -{ - if (unlikely( - (bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) || - (bio->bi_sector & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)) || - (bio->bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))) { - - return 0; - } - - /* I/O request is valid */ - return 1; -} - -/* * Handler function for all zram I/O requests. */ static void zram_make_request(struct request_queue *queue, struct bio *bio) @@ -446,7 +702,7 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio) goto error; if (!valid_io_request(zram, bio)) { - zram_stat64_inc(zram, &zram->stats.invalid_io); + atomic64_inc(&zram->stats.invalid_io); goto error; } @@ -460,130 +716,16 @@ error: bio_io_error(bio); } -static void __zram_reset_device(struct zram *zram) -{ - size_t index; - struct zram_meta *meta; - - if (!zram->init_done) - return; - - meta = zram->meta; - zram->init_done = 0; - - /* Free all pages that are still in this zram device */ - for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) { - unsigned long handle = meta->table[index].handle; - if (!handle) - continue; - - zs_free(meta->mem_pool, handle); - } - - zram_meta_free(zram->meta); - zram->meta = NULL; - /* Reset stats */ - memset(&zram->stats, 0, sizeof(zram->stats)); - - zram->disksize = 0; - set_capacity(zram->disk, 0); -} - -void zram_reset_device(struct zram *zram) -{ - down_write(&zram->init_lock); - __zram_reset_device(zram); - up_write(&zram->init_lock); -} - -void zram_meta_free(struct zram_meta *meta) -{ - zs_destroy_pool(meta->mem_pool); - kfree(meta->compress_workmem); - free_pages((unsigned long)meta->compress_buffer, 1); - vfree(meta->table); - kfree(meta); -} - -struct zram_meta *zram_meta_alloc(u64 disksize) -{ - size_t num_pages; - struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); - if (!meta) - goto out; - - meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); - if (!meta->compress_workmem) - goto free_meta; - - meta->compress_buffer = - (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1); - if (!meta->compress_buffer) { - pr_err("Error allocating compressor buffer space\n"); - goto free_workmem; - } - - num_pages = disksize >> PAGE_SHIFT; - meta->table = vzalloc(num_pages * sizeof(*meta->table)); - if (!meta->table) { - pr_err("Error allocating zram address table\n"); - goto free_buffer; - } - - meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM); - if (!meta->mem_pool) { - pr_err("Error creating memory pool\n"); - goto free_table; - } - - return meta; - -free_table: - vfree(meta->table); -free_buffer: - free_pages((unsigned long)meta->compress_buffer, 1); -free_workmem: - kfree(meta->compress_workmem); -free_meta: - kfree(meta); - meta = NULL; -out: - return meta; -} - -void zram_init_device(struct zram *zram, struct zram_meta *meta) -{ - if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) { - pr_info( - "There is little point creating a zram of greater than " - "twice the size of memory since we expect a 2:1 compression " - "ratio. Note that zram uses about 0.1%% of the size of " - "the disk when not in use so a huge zram is " - "wasteful.\n" - "\tMemory Size: %lu kB\n" - "\tSize you selected: %llu kB\n" - "Continuing anyway ...\n", - (totalram_pages << PAGE_SHIFT) >> 10, zram->disksize >> 10 - ); - } - - /* zram devices sort of resembles non-rotational disks */ - queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); - - zram->meta = meta; - zram->init_done = 1; - - pr_debug("Initialization done!\n"); -} - static void zram_slot_free_notify(struct block_device *bdev, unsigned long index) { struct zram *zram; zram = bdev->bd_disk->private_data; + down_write(&zram->lock); zram_free_page(zram, index); - zram_stat64_inc(zram, &zram->stats.notify_free); + up_write(&zram->lock); + atomic64_inc(&zram->stats.notify_free); } static const struct block_device_operations zram_devops = { @@ -591,19 +733,49 @@ static const struct block_device_operations zram_devops = { .owner = THIS_MODULE }; +static DEVICE_ATTR(disksize, S_IRUGO | S_IWUSR, + disksize_show, disksize_store); +static DEVICE_ATTR(initstate, S_IRUGO, initstate_show, NULL); +static DEVICE_ATTR(reset, S_IWUSR, NULL, reset_store); +static DEVICE_ATTR(num_reads, S_IRUGO, num_reads_show, NULL); +static DEVICE_ATTR(num_writes, S_IRUGO, num_writes_show, NULL); +static DEVICE_ATTR(invalid_io, S_IRUGO, invalid_io_show, NULL); +static DEVICE_ATTR(notify_free, S_IRUGO, notify_free_show, NULL); +static DEVICE_ATTR(zero_pages, S_IRUGO, zero_pages_show, NULL); +static DEVICE_ATTR(orig_data_size, S_IRUGO, orig_data_size_show, NULL); +static DEVICE_ATTR(compr_data_size, S_IRUGO, compr_data_size_show, NULL); +static DEVICE_ATTR(mem_used_total, S_IRUGO, mem_used_total_show, NULL); + +static struct attribute *zram_disk_attrs[] = { + &dev_attr_disksize.attr, + &dev_attr_initstate.attr, + &dev_attr_reset.attr, + &dev_attr_num_reads.attr, + &dev_attr_num_writes.attr, + &dev_attr_invalid_io.attr, + &dev_attr_notify_free.attr, + &dev_attr_zero_pages.attr, + &dev_attr_orig_data_size.attr, + &dev_attr_compr_data_size.attr, + &dev_attr_mem_used_total.attr, + NULL, +}; + +static struct attribute_group zram_disk_attr_group = { + .attrs = zram_disk_attrs, +}; + static int create_device(struct zram *zram, int device_id) { - int ret = 0; + int ret = -ENOMEM; init_rwsem(&zram->lock); init_rwsem(&zram->init_lock); - spin_lock_init(&zram->stat64_lock); zram->queue = blk_alloc_queue(GFP_KERNEL); if (!zram->queue) { pr_err("Error allocating disk queue for device %d\n", device_id); - ret = -ENOMEM; goto out; } @@ -613,11 +785,9 @@ static int create_device(struct zram *zram, int device_id) /* gendisk structure */ zram->disk = alloc_disk(1); if (!zram->disk) { - blk_cleanup_queue(zram->queue); pr_warn("Error allocating disk structure for device %d\n", device_id); - ret = -ENOMEM; - goto out; + goto out_free_queue; } zram->disk->major = zram_major; @@ -646,11 +816,17 @@ static int create_device(struct zram *zram, int device_id) &zram_disk_attr_group); if (ret < 0) { pr_warn("Error creating sysfs group"); - goto out; + goto out_free_disk; } zram->init_done = 0; + return 0; +out_free_disk: + del_gendisk(zram->disk); + put_disk(zram->disk); +out_free_queue: + blk_cleanup_queue(zram->queue); out: return ret; } @@ -669,11 +845,6 @@ static void destroy_device(struct zram *zram) blk_cleanup_queue(zram->queue); } -unsigned int zram_get_num_devices(void) -{ - return num_devices; -} - static int __init zram_init(void) { int ret, dev_id; @@ -727,8 +898,10 @@ static void __exit zram_exit(void) for (i = 0; i < num_devices; i++) { zram = &zram_devices[i]; + get_disk(zram->disk); destroy_device(zram); zram_reset_device(zram); + put_disk(zram->disk); } unregister_blkdev(zram_major, "zram"); @@ -737,12 +910,12 @@ static void __exit zram_exit(void) pr_debug("Cleanup done!\n"); } -module_param(num_devices, uint, 0); -MODULE_PARM_DESC(num_devices, "Number of zram devices"); - module_init(zram_init); module_exit(zram_exit); +module_param(num_devices, uint, 0); +MODULE_PARM_DESC(num_devices, "Number of zram devices"); + MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); MODULE_DESCRIPTION("Compressed RAM Block Device"); |