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-rw-r--r--drivers/staging/zram/Kconfig2
-rw-r--r--drivers/staging/zram/zram.txt27
-rw-r--r--drivers/staging/zram/zram_drv.c294
-rw-r--r--drivers/staging/zram/zram_drv.h17
-rw-r--r--drivers/staging/zram/zram_sysfs.c16
5 files changed, 164 insertions, 192 deletions
diff --git a/drivers/staging/zram/Kconfig b/drivers/staging/zram/Kconfig
index be5abe8e7943..983314c41349 100644
--- a/drivers/staging/zram/Kconfig
+++ b/drivers/staging/zram/Kconfig
@@ -14,7 +14,7 @@ config ZRAM
disks and maybe many more.
See zram.txt for more information.
- Project home: http://compcache.googlecode.com/
+ Project home: <https://compcache.googlecode.com/>
config ZRAM_DEBUG
bool "Compressed RAM block device debug support"
diff --git a/drivers/staging/zram/zram.txt b/drivers/staging/zram/zram.txt
index 5f75d2987564..765d790ae831 100644
--- a/drivers/staging/zram/zram.txt
+++ b/drivers/staging/zram/zram.txt
@@ -23,17 +23,17 @@ Following shows a typical sequence of steps for using zram.
This creates 4 devices: /dev/zram{0,1,2,3}
(num_devices parameter is optional. Default: 1)
-2) Set Disksize (Optional):
- Set disk size by writing the value to sysfs node 'disksize'
- (in bytes). If disksize is not given, default value of 25%
- of RAM is used.
-
- # Initialize /dev/zram0 with 50MB disksize
- echo $((50*1024*1024)) > /sys/block/zram0/disksize
-
- NOTE: disksize cannot be changed if the disk contains any
- data. So, for such a disk, you need to issue 'reset' (see below)
- before you can change its disksize.
+2) Set Disksize
+ Set disk size by writing the value to sysfs node 'disksize'.
+ The value can be either in bytes or you can use mem suffixes.
+ Examples:
+ # Initialize /dev/zram0 with 50MB disksize
+ echo $((50*1024*1024)) > /sys/block/zram0/disksize
+
+ # Using mem suffixes
+ echo 256K > /sys/block/zram0/disksize
+ echo 512M > /sys/block/zram0/disksize
+ echo 1G > /sys/block/zram0/disksize
3) Activate:
mkswap /dev/zram0
@@ -65,8 +65,9 @@ Following shows a typical sequence of steps for using zram.
echo 1 > /sys/block/zram0/reset
echo 1 > /sys/block/zram1/reset
- (This frees all the memory allocated for the given device).
-
+ This frees all the memory allocated for the given device and
+ resets the disksize to zero. You must set the disksize again
+ before reusing the device.
Please report any problems at:
- Mailing list: linux-mm-cc at laptop dot org
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index f2a73bd739fb..5918fd7d7e36 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -40,17 +40,7 @@ static int zram_major;
struct zram *zram_devices;
/* Module params (documentation at end) */
-static 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 unsigned int num_devices = 1;
static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc)
{
@@ -71,22 +61,22 @@ 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,
+static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
- return zram->table[index].flags & BIT(flag);
+ return meta->table[index].flags & BIT(flag);
}
-static void zram_set_flag(struct zram *zram, u32 index,
+static void zram_set_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
- zram->table[index].flags |= BIT(flag);
+ meta->table[index].flags |= BIT(flag);
}
-static void zram_clear_flag(struct zram *zram, u32 index,
+static void zram_clear_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
- zram->table[index].flags &= ~BIT(flag);
+ meta->table[index].flags &= ~BIT(flag);
}
static int page_zero_filled(void *ptr)
@@ -104,66 +94,38 @@ static int page_zero_filled(void *ptr)
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)
{
- unsigned long handle = zram->table[index].handle;
- u16 size = zram->table[index].size;
+ struct zram_meta *meta = zram->meta;
+ unsigned long handle = meta->table[index].handle;
+ u16 size = meta->table[index].size;
if (unlikely(!handle)) {
/*
* 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);
+ if (zram_test_flag(meta, index, ZRAM_ZERO)) {
+ zram_clear_flag(meta, index, ZRAM_ZERO);
+ zram->stats.pages_zero--;
}
return;
}
if (unlikely(size > max_zpage_size))
- zram_stat_dec(&zram->stats.bad_compress);
+ zram->stats.bad_compress--;
- zs_free(zram->mem_pool, handle);
+ zs_free(meta->mem_pool, handle);
if (size <= PAGE_SIZE / 2)
- zram_stat_dec(&zram->stats.good_compress);
+ zram->stats.good_compress--;
zram_stat64_sub(zram, &zram->stats.compr_size,
- zram->table[index].size);
- zram_stat_dec(&zram->stats.pages_stored);
+ meta->table[index].size);
+ zram->stats.pages_stored--;
- zram->table[index].handle = 0;
- zram->table[index].size = 0;
+ meta->table[index].handle = 0;
+ meta->table[index].size = 0;
}
static void handle_zero_page(struct bio_vec *bvec)
@@ -188,20 +150,21 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
int ret = LZO_E_OK;
size_t clen = PAGE_SIZE;
unsigned char *cmem;
- unsigned long handle = zram->table[index].handle;
+ struct zram_meta *meta = zram->meta;
+ unsigned long handle = meta->table[index].handle;
- if (!handle || zram_test_flag(zram, index, ZRAM_ZERO)) {
+ if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) {
memset(mem, 0, PAGE_SIZE);
return 0;
}
- cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
- if (zram->table[index].size == PAGE_SIZE)
+ cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
+ if (meta->table[index].size == PAGE_SIZE)
memcpy(mem, cmem, PAGE_SIZE);
else
- ret = lzo1x_decompress_safe(cmem, zram->table[index].size,
+ ret = lzo1x_decompress_safe(cmem, meta->table[index].size,
mem, &clen);
- zs_unmap_object(zram->mem_pool, handle);
+ zs_unmap_object(meta->mem_pool, handle);
/* Should NEVER happen. Return bio error if it does. */
if (unlikely(ret != LZO_E_OK)) {
@@ -219,20 +182,21 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
int ret;
struct page *page;
unsigned char *user_mem, *uncmem = NULL;
-
+ struct zram_meta *meta = zram->meta;
page = bvec->bv_page;
- if (unlikely(!zram->table[index].handle) ||
- zram_test_flag(zram, index, ZRAM_ZERO)) {
+ if (unlikely(!meta->table[index].handle) ||
+ zram_test_flag(meta, index, ZRAM_ZERO)) {
handle_zero_page(bvec);
return 0;
}
- user_mem = kmap_atomic(page);
if (is_partial_io(bvec))
/* Use a temporary buffer to decompress the page */
- uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
- else
+ uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
+
+ user_mem = kmap_atomic(page);
+ if (!is_partial_io(bvec))
uncmem = user_mem;
if (!uncmem) {
@@ -270,18 +234,18 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
unsigned long handle;
struct page *page;
unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
+ struct zram_meta *meta = zram->meta;
page = bvec->bv_page;
- src = zram->compress_buffer;
+ src = meta->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);
+ uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
if (!uncmem) {
- pr_info("Error allocating temp memory!\n");
ret = -ENOMEM;
goto out;
}
@@ -294,8 +258,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
* System overwrites unused sectors. Free memory associated
* with this sector now.
*/
- if (zram->table[index].handle ||
- zram_test_flag(zram, index, ZRAM_ZERO))
+ if (meta->table[index].handle ||
+ zram_test_flag(meta, index, ZRAM_ZERO))
zram_free_page(zram, index);
user_mem = kmap_atomic(page);
@@ -310,16 +274,17 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
}
if (page_zero_filled(uncmem)) {
- if (!is_partial_io(bvec))
- kunmap_atomic(user_mem);
- zram_stat_inc(&zram->stats.pages_zero);
- zram_set_flag(zram, index, ZRAM_ZERO);
+ kunmap_atomic(user_mem);
+ if (is_partial_io(bvec))
+ kfree(uncmem);
+ zram->stats.pages_zero++;
+ zram_set_flag(meta, index, ZRAM_ZERO);
ret = 0;
goto out;
}
ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
- zram->compress_workmem);
+ meta->compress_workmem);
if (!is_partial_io(bvec)) {
kunmap_atomic(user_mem);
@@ -333,21 +298,21 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
}
if (unlikely(clen > max_zpage_size)) {
- zram_stat_inc(&zram->stats.bad_compress);
+ zram->stats.bad_compress++;
clen = PAGE_SIZE;
src = NULL;
if (is_partial_io(bvec))
src = uncmem;
}
- handle = zs_malloc(zram->mem_pool, clen);
+ handle = zs_malloc(meta->mem_pool, clen);
if (!handle) {
pr_info("Error allocating memory for compressed "
"page: %u, size=%zu\n", index, clen);
ret = -ENOMEM;
goto out;
}
- cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
+ cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
src = kmap_atomic(page);
@@ -355,16 +320,16 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
kunmap_atomic(src);
- zs_unmap_object(zram->mem_pool, handle);
+ zs_unmap_object(meta->mem_pool, handle);
- zram->table[index].handle = handle;
- zram->table[index].size = clen;
+ meta->table[index].handle = handle;
+ meta->table[index].size = clen;
/* Update stats */
zram_stat64_add(zram, &zram->stats.compr_size, clen);
- zram_stat_inc(&zram->stats.pages_stored);
+ zram->stats.pages_stored++;
if (clen <= PAGE_SIZE / 2)
- zram_stat_inc(&zram->stats.good_compress);
+ zram->stats.good_compress++;
out:
if (is_partial_io(bvec))
@@ -479,16 +444,13 @@ 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;
+ goto error;
if (!valid_io_request(zram, bio)) {
zram_stat64_inc(zram, &zram->stats.invalid_io);
- goto error_unlock;
+ goto error;
}
__zram_make_request(zram, bio, bio_data_dir(bio));
@@ -496,44 +458,38 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio)
return;
-error_unlock:
- up_read(&zram->init_lock);
error:
+ up_read(&zram->init_lock);
bio_io_error(bio);
}
-void __zram_reset_device(struct zram *zram)
+static void __zram_reset_device(struct zram *zram)
{
size_t index;
+ struct zram_meta *meta;
- zram->init_done = 0;
-
- /* Free various per-device buffers */
- kfree(zram->compress_workmem);
- free_pages((unsigned long)zram->compress_buffer, 1);
+ if (!zram->init_done)
+ return;
- zram->compress_workmem = NULL;
- zram->compress_buffer = NULL;
+ 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 = zram->table[index].handle;
+ unsigned long handle = meta->table[index].handle;
if (!handle)
continue;
- zs_free(zram->mem_pool, handle);
+ zs_free(meta->mem_pool, handle);
}
- vfree(zram->table);
- zram->table = NULL;
-
- zs_destroy_pool(zram->mem_pool);
- zram->mem_pool = NULL;
-
+ 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)
@@ -543,69 +499,84 @@ void zram_reset_device(struct zram *zram)
up_write(&zram->init_lock);
}
-int zram_init_device(struct zram *zram)
+void zram_meta_free(struct zram_meta *meta)
{
- int ret;
- size_t num_pages;
-
- down_write(&zram->init_lock);
-
- if (zram->init_done) {
- up_write(&zram->init_lock);
- return 0;
- }
+ zs_destroy_pool(meta->mem_pool);
+ kfree(meta->compress_workmem);
+ free_pages((unsigned long)meta->compress_buffer, 1);
+ vfree(meta->table);
+ kfree(meta);
+}
- zram_set_disksize(zram, totalram_pages << PAGE_SHIFT);
+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;
- 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_no_table;
- }
+ meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+ if (!meta->compress_workmem)
+ goto free_meta;
- zram->compress_buffer =
+ meta->compress_buffer =
(void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
- if (!zram->compress_buffer) {
+ if (!meta->compress_buffer) {
pr_err("Error allocating compressor buffer space\n");
- ret = -ENOMEM;
- goto fail_no_table;
+ goto free_workmem;
}
- num_pages = zram->disksize >> PAGE_SHIFT;
- zram->table = vzalloc(num_pages * sizeof(*zram->table));
- if (!zram->table) {
+ num_pages = disksize >> PAGE_SHIFT;
+ meta->table = vzalloc(num_pages * sizeof(*meta->table));
+ if (!meta->table) {
pr_err("Error allocating zram address table\n");
- ret = -ENOMEM;
- goto fail_no_table;
+ goto free_buffer;
}
- set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
+ meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM);
+ if (!meta->mem_pool) {
+ pr_err("Error creating memory pool\n");
+ goto free_table;
+ }
- /* zram devices sort of resembles non-rotational disks */
- queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
+ return meta;
- zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM);
- if (!zram->mem_pool) {
- pr_err("Error creating memory pool\n");
- ret = -ENOMEM;
- goto fail;
+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;
- 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:
- __zram_reset_device(zram);
- up_write(&zram->init_lock);
- pr_err("Initialization failed: err=%d\n", ret);
- return ret;
}
static void zram_slot_free_notify(struct block_device *bdev,
@@ -724,13 +695,7 @@ static int __init zram_init(void)
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);
zram_devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL);
if (!zram_devices) {
ret = -ENOMEM;
@@ -743,6 +708,8 @@ static int __init zram_init(void)
goto free_devices;
}
+ pr_info("Created %u device(s) ...\n", num_devices);
+
return 0;
free_devices:
@@ -764,8 +731,7 @@ static void __exit zram_exit(void)
zram = &zram_devices[i];
destroy_device(zram);
- if (zram->init_done)
- zram_reset_device(zram);
+ zram_reset_device(zram);
}
unregister_blkdev(zram_major, "zram");
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index df2eec407db6..2d1a3f1e8edb 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -28,9 +28,6 @@ static const unsigned max_num_devices = 32;
/*-- Configurable parameters */
-/* Default zram disk size: 25% of total RAM */
-static const unsigned default_disksize_perc_ram = 25;
-
/*
* Pages that compress to size greater than this are stored
* uncompressed in memory.
@@ -86,11 +83,15 @@ struct zram_stats {
u32 bad_compress; /* % of pages with compression ratio>=75% */
};
-struct zram {
- struct zs_pool *mem_pool;
+struct zram_meta {
void *compress_workmem;
void *compress_buffer;
struct table *table;
+ struct zs_pool *mem_pool;
+};
+
+struct zram {
+ struct zram_meta *meta;
spinlock_t stat64_lock; /* protect 64-bit stats */
struct rw_semaphore lock; /* protect compression buffers and table
* against concurrent read and writes */
@@ -114,7 +115,9 @@ unsigned int zram_get_num_devices(void);
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);
+extern struct zram_meta *zram_meta_alloc(u64 disksize);
+extern void zram_meta_free(struct zram_meta *meta);
+extern void zram_init_device(struct zram *zram, struct zram_meta *meta);
#endif
diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c
index de1eacf65dbd..e6a929d452f7 100644
--- a/drivers/staging/zram/zram_sysfs.c
+++ b/drivers/staging/zram/zram_sysfs.c
@@ -56,21 +56,26 @@ 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 = PAGE_ALIGN(disksize);
+ zram->disksize = disksize;
set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
+ zram_init_device(zram, meta);
up_write(&zram->init_lock);
return len;
@@ -110,11 +115,7 @@ 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);
- up_write(&zram->init_lock);
-
+ zram_reset_device(zram);
return len;
}
@@ -185,9 +186,10 @@ static ssize_t mem_used_total_show(struct device *dev,
{
u64 val = 0;
struct zram *zram = dev_to_zram(dev);
+ struct zram_meta *meta = zram->meta;
if (zram->init_done)
- val = zs_get_total_size_bytes(zram->mem_pool);
+ val = zs_get_total_size_bytes(meta->mem_pool);
return sprintf(buf, "%llu\n", val);
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-14 23:22:59 +0200