/drivers/staging/zram/zram_drv.c
https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t · C · 855 lines · 630 code · 162 blank · 63 comment · 75 complexity · 4d4bb587ce416dce4f72905964eebfee MD5 · raw file
- /*
- * Compressed RAM block device
- *
- * Copyright (C) 2008, 2009, 2010 Nitin Gupta
- *
- * This code is released using a dual license strategy: BSD/GPL
- * You can choose the licence that better fits your requirements.
- *
- * Released under the terms of 3-clause BSD License
- * Released under the terms of GNU General Public License Version 2.0
- *
- * Project home: http://compcache.googlecode.com
- */
- #define KMSG_COMPONENT "zram"
- #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
- #ifdef CONFIG_ZRAM_DEBUG
- #define DEBUG
- #endif
- #include <linux/module.h>
- #include <linux/kernel.h>
- #include <linux/bio.h>
- #include <linux/bitops.h>
- #include <linux/blkdev.h>
- #include <linux/buffer_head.h>
- #include <linux/device.h>
- #include <linux/genhd.h>
- #include <linux/highmem.h>
- #include <linux/slab.h>
- #include <linux/lzo.h>
- #include <linux/string.h>
- #include <linux/vmalloc.h>
- #include "zram_drv.h"
- /* Globals */
- static int zram_major;
- struct zram *devices;
- /* Module params (documentation at end) */
- unsigned int num_devices;
- static void zram_stat_inc(u32 *v)
- {
- *v = *v + 1;
- }
- static void zram_stat_dec(u32 *v)
- {
- *v = *v - 1;
- }
- static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc)
- {
- spin_lock(&zram->stat64_lock);
- *v = *v + inc;
- spin_unlock(&zram->stat64_lock);
- }
- static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec)
- {
- spin_lock(&zram->stat64_lock);
- *v = *v - dec;
- spin_unlock(&zram->stat64_lock);
- }
- static void zram_stat64_inc(struct zram *zram, u64 *v)
- {
- zram_stat64_add(zram, v, 1);
- }
- static int zram_test_flag(struct zram *zram, u32 index,
- enum zram_pageflags flag)
- {
- return zram->table[index].flags & BIT(flag);
- }
- static void zram_set_flag(struct zram *zram, u32 index,
- enum zram_pageflags flag)
- {
- zram->table[index].flags |= BIT(flag);
- }
- static void zram_clear_flag(struct zram *zram, u32 index,
- enum zram_pageflags flag)
- {
- zram->table[index].flags &= ~BIT(flag);
- }
- static int page_zero_filled(void *ptr)
- {
- unsigned int pos;
- unsigned long *page;
- page = (unsigned long *)ptr;
- for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) {
- if (page[pos])
- return 0;
- }
- return 1;
- }
- static void zram_set_disksize(struct zram *zram, size_t totalram_bytes)
- {
- if (!zram->disksize) {
- pr_info(
- "disk size not provided. You can use disksize_kb module "
- "param to specify size.\nUsing default: (%u%% of RAM).\n",
- default_disksize_perc_ram
- );
- zram->disksize = default_disksize_perc_ram *
- (totalram_bytes / 100);
- }
- if (zram->disksize > 2 * (totalram_bytes)) {
- 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: %zu kB\n"
- "\tSize you selected: %llu kB\n"
- "Continuing anyway ...\n",
- totalram_bytes >> 10, zram->disksize
- );
- }
- zram->disksize &= PAGE_MASK;
- }
- static void zram_free_page(struct zram *zram, size_t index)
- {
- u32 clen;
- void *obj;
- struct page *page = zram->table[index].page;
- u32 offset = zram->table[index].offset;
- if (unlikely(!page)) {
- /*
- * No memory is allocated for zero filled pages.
- * Simply clear zero page flag.
- */
- if (zram_test_flag(zram, index, ZRAM_ZERO)) {
- zram_clear_flag(zram, index, ZRAM_ZERO);
- zram_stat_dec(&zram->stats.pages_zero);
- }
- return;
- }
- if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
- clen = PAGE_SIZE;
- __free_page(page);
- zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED);
- zram_stat_dec(&zram->stats.pages_expand);
- goto out;
- }
- obj = kmap_atomic(page, KM_USER0) + offset;
- clen = xv_get_object_size(obj) - sizeof(struct zobj_header);
- kunmap_atomic(obj, KM_USER0);
- xv_free(zram->mem_pool, page, offset);
- if (clen <= PAGE_SIZE / 2)
- zram_stat_dec(&zram->stats.good_compress);
- out:
- zram_stat64_sub(zram, &zram->stats.compr_size, clen);
- zram_stat_dec(&zram->stats.pages_stored);
- zram->table[index].page = NULL;
- zram->table[index].offset = 0;
- }
- static void handle_zero_page(struct bio_vec *bvec)
- {
- struct page *page = bvec->bv_page;
- void *user_mem;
- user_mem = kmap_atomic(page, KM_USER0);
- memset(user_mem + bvec->bv_offset, 0, bvec->bv_len);
- kunmap_atomic(user_mem, KM_USER0);
- flush_dcache_page(page);
- }
- static void handle_uncompressed_page(struct zram *zram, struct bio_vec *bvec,
- u32 index, int offset)
- {
- struct page *page = bvec->bv_page;
- unsigned char *user_mem, *cmem;
- user_mem = kmap_atomic(page, KM_USER0);
- cmem = kmap_atomic(zram->table[index].page, KM_USER1);
- memcpy(user_mem + bvec->bv_offset, cmem + offset, bvec->bv_len);
- kunmap_atomic(cmem, KM_USER1);
- kunmap_atomic(user_mem, KM_USER0);
- flush_dcache_page(page);
- }
- static inline int is_partial_io(struct bio_vec *bvec)
- {
- return bvec->bv_len != PAGE_SIZE;
- }
- static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
- u32 index, int offset, struct bio *bio)
- {
- int ret;
- size_t clen;
- struct page *page;
- struct zobj_header *zheader;
- unsigned char *user_mem, *cmem, *uncmem = NULL;
- page = bvec->bv_page;
- if (zram_test_flag(zram, index, ZRAM_ZERO)) {
- handle_zero_page(bvec);
- return 0;
- }
- /* Requested page is not present in compressed area */
- if (unlikely(!zram->table[index].page)) {
- pr_debug("Read before write: sector=%lu, size=%u",
- (ulong)(bio->bi_sector), bio->bi_size);
- handle_zero_page(bvec);
- return 0;
- }
- /* Page is stored uncompressed since it's incompressible */
- if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
- handle_uncompressed_page(zram, bvec, index, offset);
- return 0;
- }
- if (is_partial_io(bvec)) {
- /* Use a temporary buffer to decompress the page */
- uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!uncmem) {
- pr_info("Error allocating temp memory!\n");
- return -ENOMEM;
- }
- }
- user_mem = kmap_atomic(page, KM_USER0);
- if (!is_partial_io(bvec))
- uncmem = user_mem;
- clen = PAGE_SIZE;
- cmem = kmap_atomic(zram->table[index].page, KM_USER1) +
- zram->table[index].offset;
- ret = lzo1x_decompress_safe(cmem + sizeof(*zheader),
- xv_get_object_size(cmem) - sizeof(*zheader),
- uncmem, &clen);
- if (is_partial_io(bvec)) {
- memcpy(user_mem + bvec->bv_offset, uncmem + offset,
- bvec->bv_len);
- kfree(uncmem);
- }
- kunmap_atomic(cmem, KM_USER1);
- kunmap_atomic(user_mem, KM_USER0);
- /* 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);
- return ret;
- }
- flush_dcache_page(page);
- return 0;
- }
- static int zram_read_before_write(struct zram *zram, char *mem, u32 index)
- {
- int ret;
- size_t clen = PAGE_SIZE;
- struct zobj_header *zheader;
- unsigned char *cmem;
- if (zram_test_flag(zram, index, ZRAM_ZERO) ||
- !zram->table[index].page) {
- memset(mem, 0, PAGE_SIZE);
- return 0;
- }
- cmem = kmap_atomic(zram->table[index].page, KM_USER0) +
- zram->table[index].offset;
- /* Page is stored uncompressed since it's incompressible */
- if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
- memcpy(mem, cmem, PAGE_SIZE);
- kunmap_atomic(cmem, KM_USER0);
- return 0;
- }
- ret = lzo1x_decompress_safe(cmem + sizeof(*zheader),
- xv_get_object_size(cmem) - sizeof(*zheader),
- mem, &clen);
- kunmap_atomic(cmem, KM_USER0);
- /* 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);
- return ret;
- }
- return 0;
- }
- static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
- int offset)
- {
- int ret;
- u32 store_offset;
- size_t clen;
- struct zobj_header *zheader;
- struct page *page, *page_store;
- unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
- page = bvec->bv_page;
- src = zram->compress_buffer;
- if (is_partial_io(bvec)) {
- /*
- * This is a partial IO. We need to read the full page
- * before to write the changes.
- */
- uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!uncmem) {
- pr_info("Error allocating temp memory!\n");
- ret = -ENOMEM;
- goto out;
- }
- ret = zram_read_before_write(zram, uncmem, index);
- if (ret) {
- kfree(uncmem);
- goto out;
- }
- }
- /*
- * System overwrites unused sectors. Free memory associated
- * with this sector now.
- */
- if (zram->table[index].page ||
- zram_test_flag(zram, index, ZRAM_ZERO))
- zram_free_page(zram, index);
- user_mem = kmap_atomic(page, KM_USER0);
- if (is_partial_io(bvec))
- memcpy(uncmem + offset, user_mem + bvec->bv_offset,
- bvec->bv_len);
- else
- uncmem = user_mem;
- if (page_zero_filled(uncmem)) {
- kunmap_atomic(user_mem, KM_USER0);
- if (is_partial_io(bvec))
- kfree(uncmem);
- zram_stat_inc(&zram->stats.pages_zero);
- zram_set_flag(zram, index, ZRAM_ZERO);
- ret = 0;
- goto out;
- }
- ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
- zram->compress_workmem);
- kunmap_atomic(user_mem, KM_USER0);
- if (is_partial_io(bvec))
- kfree(uncmem);
- if (unlikely(ret != LZO_E_OK)) {
- pr_err("Compression failed! err=%d\n", ret);
- goto out;
- }
- /*
- * Page is incompressible. Store it as-is (uncompressed)
- * since we do not want to return too many disk write
- * errors which has side effect of hanging the system.
- */
- if (unlikely(clen > max_zpage_size)) {
- clen = PAGE_SIZE;
- page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM);
- if (unlikely(!page_store)) {
- pr_info("Error allocating memory for "
- "incompressible page: %u\n", index);
- ret = -ENOMEM;
- goto out;
- }
- store_offset = 0;
- zram_set_flag(zram, index, ZRAM_UNCOMPRESSED);
- zram_stat_inc(&zram->stats.pages_expand);
- zram->table[index].page = page_store;
- src = kmap_atomic(page, KM_USER0);
- goto memstore;
- }
- if (xv_malloc(zram->mem_pool, clen + sizeof(*zheader),
- &zram->table[index].page, &store_offset,
- GFP_NOIO | __GFP_HIGHMEM)) {
- pr_info("Error allocating memory for compressed "
- "page: %u, size=%zu\n", index, clen);
- ret = -ENOMEM;
- goto out;
- }
- memstore:
- zram->table[index].offset = store_offset;
- cmem = kmap_atomic(zram->table[index].page, KM_USER1) +
- zram->table[index].offset;
- #if 0
- /* Back-reference needed for memory defragmentation */
- if (!zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)) {
- zheader = (struct zobj_header *)cmem;
- zheader->table_idx = index;
- cmem += sizeof(*zheader);
- }
- #endif
- memcpy(cmem, src, clen);
- kunmap_atomic(cmem, KM_USER1);
- if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)))
- kunmap_atomic(src, KM_USER0);
- /* Update stats */
- zram_stat64_add(zram, &zram->stats.compr_size, clen);
- zram_stat_inc(&zram->stats.pages_stored);
- if (clen <= PAGE_SIZE / 2)
- zram_stat_inc(&zram->stats.good_compress);
- return 0;
- out:
- if (ret)
- zram_stat64_inc(zram, &zram->stats.failed_writes);
- return ret;
- }
- static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
- int offset, struct bio *bio, int rw)
- {
- int ret;
- if (rw == READ) {
- down_read(&zram->lock);
- ret = zram_bvec_read(zram, bvec, index, offset, bio);
- up_read(&zram->lock);
- } else {
- down_write(&zram->lock);
- ret = zram_bvec_write(zram, bvec, index, offset);
- up_write(&zram->lock);
- }
- return ret;
- }
- 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 void __zram_make_request(struct zram *zram, struct bio *bio, int rw)
- {
- int i, offset;
- u32 index;
- struct bio_vec *bvec;
- switch (rw) {
- case READ:
- zram_stat64_inc(zram, &zram->stats.num_reads);
- break;
- case WRITE:
- zram_stat64_inc(zram, &zram->stats.num_writes);
- break;
- }
- index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
- offset = (bio->bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
- bio_for_each_segment(bvec, bio, i) {
- int max_transfer_size = PAGE_SIZE - offset;
- if (bvec->bv_len > max_transfer_size) {
- /*
- * zram_bvec_rw() can only make operation on a single
- * zram page. Split the bio vector.
- */
- struct bio_vec bv;
- bv.bv_page = bvec->bv_page;
- bv.bv_len = max_transfer_size;
- bv.bv_offset = bvec->bv_offset;
- if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0)
- goto out;
- bv.bv_len = bvec->bv_len - max_transfer_size;
- bv.bv_offset += max_transfer_size;
- if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0)
- goto out;
- } else
- if (zram_bvec_rw(zram, bvec, index, offset, bio, rw)
- < 0)
- goto out;
- update_position(&index, &offset, bvec);
- }
- set_bit(BIO_UPTODATE, &bio->bi_flags);
- bio_endio(bio, 0);
- return;
- out:
- bio_io_error(bio);
- }
- /*
- * 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 int zram_make_request(struct request_queue *queue, struct bio *bio)
- {
- struct zram *zram = queue->queuedata;
- 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;
- }
- __zram_make_request(zram, bio, bio_data_dir(bio));
- return 0;
- }
- void zram_reset_device(struct zram *zram)
- {
- size_t index;
- mutex_lock(&zram->init_lock);
- zram->init_done = 0;
- /* Free various per-device buffers */
- kfree(zram->compress_workmem);
- free_pages((unsigned long)zram->compress_buffer, 1);
- zram->compress_workmem = NULL;
- zram->compress_buffer = NULL;
- /* Free all pages that are still in this zram device */
- for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
- struct page *page;
- u16 offset;
- page = zram->table[index].page;
- offset = zram->table[index].offset;
- if (!page)
- continue;
- if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)))
- __free_page(page);
- else
- xv_free(zram->mem_pool, page, offset);
- }
- vfree(zram->table);
- zram->table = NULL;
- xv_destroy_pool(zram->mem_pool);
- zram->mem_pool = NULL;
- /* Reset stats */
- memset(&zram->stats, 0, sizeof(zram->stats));
- zram->disksize = 0;
- mutex_unlock(&zram->init_lock);
- }
- int zram_init_device(struct zram *zram)
- {
- int ret;
- size_t num_pages;
- mutex_lock(&zram->init_lock);
- if (zram->init_done) {
- mutex_unlock(&zram->init_lock);
- return 0;
- }
- zram_set_disksize(zram, totalram_pages << PAGE_SHIFT);
- zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
- if (!zram->compress_workmem) {
- pr_err("Error allocating compressor working memory!\n");
- ret = -ENOMEM;
- goto fail;
- }
- 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;
- }
- 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;
- }
- set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
- /* zram devices sort of resembles non-rotational disks */
- queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
- zram->mem_pool = xv_create_pool();
- if (!zram->mem_pool) {
- pr_err("Error creating memory pool\n");
- ret = -ENOMEM;
- goto fail;
- }
- zram->init_done = 1;
- mutex_unlock(&zram->init_lock);
- pr_debug("Initialization done!\n");
- return 0;
- fail:
- mutex_unlock(&zram->init_lock);
- zram_reset_device(zram);
- pr_err("Initialization failed: err=%d\n", ret);
- return ret;
- }
- void zram_slot_free_notify(struct block_device *bdev, unsigned long index)
- {
- struct zram *zram;
- zram = bdev->bd_disk->private_data;
- zram_free_page(zram, index);
- zram_stat64_inc(zram, &zram->stats.notify_free);
- }
- static const struct block_device_operations zram_devops = {
- .swap_slot_free_notify = zram_slot_free_notify,
- .owner = THIS_MODULE
- };
- static int create_device(struct zram *zram, int device_id)
- {
- int ret = 0;
- init_rwsem(&zram->lock);
- mutex_init(&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;
- }
- blk_queue_make_request(zram->queue, zram_make_request);
- zram->queue->queuedata = zram;
- /* gendisk structure */
- zram->disk = alloc_disk(1);
- if (!zram->disk) {
- blk_cleanup_queue(zram->queue);
- pr_warning("Error allocating disk structure for device %d\n",
- device_id);
- ret = -ENOMEM;
- goto out;
- }
- zram->disk->major = zram_major;
- zram->disk->first_minor = device_id;
- zram->disk->fops = &zram_devops;
- zram->disk->queue = zram->queue;
- zram->disk->private_data = zram;
- snprintf(zram->disk->disk_name, 16, "zram%d", device_id);
- /* Actual capacity set using syfs (/sys/block/zram<id>/disksize */
- set_capacity(zram->disk, 0);
- /*
- * To ensure that we always get PAGE_SIZE aligned
- * and n*PAGE_SIZED sized I/O requests.
- */
- blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE);
- blk_queue_logical_block_size(zram->disk->queue,
- ZRAM_LOGICAL_BLOCK_SIZE);
- blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
- blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
- add_disk(zram->disk);
- ret = sysfs_create_group(&disk_to_dev(zram->disk)->kobj,
- &zram_disk_attr_group);
- if (ret < 0) {
- pr_warning("Error creating sysfs group");
- goto out;
- }
- zram->init_done = 0;
- out:
- return ret;
- }
- static void destroy_device(struct zram *zram)
- {
- sysfs_remove_group(&disk_to_dev(zram->disk)->kobj,
- &zram_disk_attr_group);
- if (zram->disk) {
- del_gendisk(zram->disk);
- put_disk(zram->disk);
- }
- if (zram->queue)
- blk_cleanup_queue(zram->queue);
- }
- static int __init zram_init(void)
- {
- int ret, dev_id;
- if (num_devices > max_num_devices) {
- pr_warning("Invalid value for num_devices: %u\n",
- num_devices);
- ret = -EINVAL;
- goto out;
- }
- zram_major = register_blkdev(0, "zram");
- if (zram_major <= 0) {
- pr_warning("Unable to get major number\n");
- ret = -EBUSY;
- goto out;
- }
- if (!num_devices) {
- pr_info("num_devices not specified. Using default: 1\n");
- 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) {
- ret = -ENOMEM;
- goto unregister;
- }
- for (dev_id = 0; dev_id < num_devices; dev_id++) {
- ret = create_device(&devices[dev_id], dev_id);
- if (ret)
- goto free_devices;
- }
- return 0;
- free_devices:
- while (dev_id)
- destroy_device(&devices[--dev_id]);
- kfree(devices);
- unregister:
- unregister_blkdev(zram_major, "zram");
- out:
- return ret;
- }
- static void __exit zram_exit(void)
- {
- int i;
- struct zram *zram;
- for (i = 0; i < num_devices; i++) {
- zram = &devices[i];
- destroy_device(zram);
- if (zram->init_done)
- zram_reset_device(zram);
- }
- unregister_blkdev(zram_major, "zram");
- kfree(devices);
- 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_LICENSE("Dual BSD/GPL");
- MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");
- MODULE_DESCRIPTION("Compressed RAM Block Device");