mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
e46e33152e
Finally, we separated zram->lock dependency from 32bit stat/ table handling so there is no reason to use rw_semaphore between read and write path so this patch removes the lock from read path totally and changes rw_semaphore with mutex. So, we could do old: read-read: OK read-write: NO write-write: NO Now: read-read: OK read-write: OK write-write: NO The below data proves mixed workload performs well 11 times and there is also enhance on write-write path because current rw-semaphore doesn't support SPIN_ON_OWNER. It's side effect but anyway good thing for us. Write-related tests perform better (from 61% to 1058%) but read path has good/bad(from -2.22% to 1.45%) but they are all marginal within stddev. CPU 12 iozone -t -T -l 12 -u 12 -r 16K -s 60M -I +Z -V 0 ==Initial write ==Initial write records: 10 records: 10 avg: 516189.16 avg: 839907.96 std: 22486.53 (4.36%) std: 47902.17 (5.70%) max: 546970.60 max: 909910.35 min: 481131.54 min: 751148.38 ==Rewrite ==Rewrite records: 10 records: 10 avg: 509527.98 avg: 1050156.37 std: 45799.94 (8.99%) std: 40695.44 (3.88%) max: 611574.27 max: 1111929.26 min: 443679.95 min: 980409.62 ==Read ==Read records: 10 records: 10 avg: 4408624.17 avg: 4472546.76 std: 281152.61 (6.38%) std: 163662.78 (3.66%) max: 4867888.66 max: 4727351.03 min: 4058347.69 min: 4126520.88 ==Re-read ==Re-read records: 10 records: 10 avg: 4462147.53 avg: 4363257.75 std: 283546.11 (6.35%) std: 247292.63 (5.67%) max: 4912894.44 max: 4677241.75 min: 4131386.50 min: 4035235.84 ==Reverse Read ==Reverse Read records: 10 records: 10 avg: 4565865.97 avg: 4485818.08 std: 313395.63 (6.86%) std: 248470.10 (5.54%) max: 5232749.16 max: 4789749.94 min: 4185809.62 min: 3963081.34 ==Stride read ==Stride read records: 10 records: 10 avg: 4515981.80 avg: 4418806.01 std: 211192.32 (4.68%) std: 212837.97 (4.82%) max: 4889287.28 max: 4686967.22 min: 4210362.00 min: 4083041.84 ==Random read ==Random read records: 10 records: 10 avg: 4410525.23 avg: 4387093.18 std: 236693.22 (5.37%) std: 235285.23 (5.36%) max: 4713698.47 max: 4669760.62 min: 4057163.62 min: 3952002.16 ==Mixed workload ==Mixed workload records: 10 records: 10 avg: 243234.25 avg: 2818677.27 std: 28505.07 (11.72%) std: 195569.70 (6.94%) max: 288905.23 max: 3126478.11 min: 212473.16 min: 2484150.69 ==Random write ==Random write records: 10 records: 10 avg: 555887.07 avg: 1053057.79 std: 70841.98 (12.74%) std: 35195.36 (3.34%) max: 683188.28 max: 1096125.73 min: 437299.57 min: 992481.93 ==Pwrite ==Pwrite records: 10 records: 10 avg: 501745.93 avg: 810363.09 std: 16373.54 (3.26%) std: 19245.01 (2.37%) max: 518724.52 max: 833359.70 min: 464208.73 min: 765501.87 ==Pread ==Pread records: 10 records: 10 avg: 4539894.60 avg: 4457680.58 std: 197094.66 (4.34%) std: 188965.60 (4.24%) max: 4877170.38 max: 4689905.53 min: 4226326.03 min: 4095739.72 Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
959 lines
22 KiB
C
959 lines
22 KiB
C
/*
|
|
* Compressed RAM block device
|
|
*
|
|
* Copyright (C) 2008, 2009, 2010 Nitin Gupta
|
|
* 2012, 2013 Minchan Kim
|
|
*
|
|
* 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
|
|
*
|
|
*/
|
|
|
|
#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;
|
|
static struct zram *zram_devices;
|
|
|
|
/* Module params (documentation at end) */
|
|
static unsigned int num_devices = 1;
|
|
|
|
static inline struct zram *dev_to_zram(struct device *dev)
|
|
{
|
|
return (struct zram *)dev_to_disk(dev)->private_data;
|
|
}
|
|
|
|
static ssize_t disksize_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
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 ssize_t zero_pages_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct zram *zram = dev_to_zram(dev);
|
|
|
|
return sprintf(buf, "%u\n", atomic_read(&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)(atomic_read(&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);
|
|
}
|
|
|
|
/* flag operations needs meta->tb_lock */
|
|
static int zram_test_flag(struct zram_meta *meta, u32 index,
|
|
enum zram_pageflags flag)
|
|
{
|
|
return meta->table[index].flags & BIT(flag);
|
|
}
|
|
|
|
static void zram_set_flag(struct zram_meta *meta, u32 index,
|
|
enum zram_pageflags flag)
|
|
{
|
|
meta->table[index].flags |= BIT(flag);
|
|
}
|
|
|
|
static void zram_clear_flag(struct zram_meta *meta, u32 index,
|
|
enum zram_pageflags flag)
|
|
{
|
|
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_iter.bi_sector &
|
|
(ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)))
|
|
return 0;
|
|
if (unlikely(bio->bi_iter.bi_size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))
|
|
return 0;
|
|
|
|
start = bio->bi_iter.bi_sector;
|
|
end = start + (bio->bi_iter.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;
|
|
}
|
|
|
|
rwlock_init(&meta->tb_lock);
|
|
mutex_init(&meta->buffer_lock);
|
|
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;
|
|
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 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);
|
|
}
|
|
|
|
/* NOTE: caller should hold meta->tb_lock with write-side */
|
|
static void zram_free_page(struct zram *zram, size_t index)
|
|
{
|
|
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(meta, index, ZRAM_ZERO)) {
|
|
zram_clear_flag(meta, index, ZRAM_ZERO);
|
|
atomic_dec(&zram->stats.pages_zero);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (unlikely(size > max_zpage_size))
|
|
atomic_dec(&zram->stats.bad_compress);
|
|
|
|
zs_free(meta->mem_pool, handle);
|
|
|
|
if (size <= PAGE_SIZE / 2)
|
|
atomic_dec(&zram->stats.good_compress);
|
|
|
|
atomic64_sub(meta->table[index].size, &zram->stats.compr_size);
|
|
atomic_dec(&zram->stats.pages_stored);
|
|
|
|
meta->table[index].handle = 0;
|
|
meta->table[index].size = 0;
|
|
}
|
|
|
|
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;
|
|
struct zram_meta *meta = zram->meta;
|
|
unsigned long handle;
|
|
u16 size;
|
|
|
|
read_lock(&meta->tb_lock);
|
|
handle = meta->table[index].handle;
|
|
size = meta->table[index].size;
|
|
|
|
if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) {
|
|
read_unlock(&meta->tb_lock);
|
|
clear_page(mem);
|
|
return 0;
|
|
}
|
|
|
|
cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
|
|
if (size == PAGE_SIZE)
|
|
copy_page(mem, cmem);
|
|
else
|
|
ret = lzo1x_decompress_safe(cmem, size, mem, &clen);
|
|
zs_unmap_object(meta->mem_pool, handle);
|
|
read_unlock(&meta->tb_lock);
|
|
|
|
/* 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);
|
|
atomic64_inc(&zram->stats.failed_reads);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
|
|
u32 index, int offset, struct bio *bio)
|
|
{
|
|
int ret;
|
|
struct page *page;
|
|
unsigned char *user_mem, *uncmem = NULL;
|
|
struct zram_meta *meta = zram->meta;
|
|
page = bvec->bv_page;
|
|
|
|
read_lock(&meta->tb_lock);
|
|
if (unlikely(!meta->table[index].handle) ||
|
|
zram_test_flag(meta, index, ZRAM_ZERO)) {
|
|
read_unlock(&meta->tb_lock);
|
|
handle_zero_page(bvec);
|
|
return 0;
|
|
}
|
|
read_unlock(&meta->tb_lock);
|
|
|
|
if (is_partial_io(bvec))
|
|
/* Use a temporary buffer to decompress the page */
|
|
uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
|
|
|
|
user_mem = kmap_atomic(page);
|
|
if (!is_partial_io(bvec))
|
|
uncmem = user_mem;
|
|
|
|
if (!uncmem) {
|
|
pr_info("Unable to allocate temp memory\n");
|
|
ret = -ENOMEM;
|
|
goto out_cleanup;
|
|
}
|
|
|
|
ret = zram_decompress_page(zram, uncmem, index);
|
|
/* Should NEVER happen. Return bio error if it does. */
|
|
if (unlikely(ret != LZO_E_OK))
|
|
goto out_cleanup;
|
|
|
|
if (is_partial_io(bvec))
|
|
memcpy(user_mem + bvec->bv_offset, uncmem + offset,
|
|
bvec->bv_len);
|
|
|
|
flush_dcache_page(page);
|
|
ret = 0;
|
|
out_cleanup:
|
|
kunmap_atomic(user_mem);
|
|
if (is_partial_io(bvec))
|
|
kfree(uncmem);
|
|
return ret;
|
|
}
|
|
|
|
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
|
|
int offset)
|
|
{
|
|
int ret = 0;
|
|
size_t clen;
|
|
unsigned long handle;
|
|
struct page *page;
|
|
unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
|
|
struct zram_meta *meta = zram->meta;
|
|
bool locked = false;
|
|
|
|
page = bvec->bv_page;
|
|
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_NOIO);
|
|
if (!uncmem) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
ret = zram_decompress_page(zram, uncmem, index);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&meta->buffer_lock);
|
|
locked = true;
|
|
user_mem = kmap_atomic(page);
|
|
|
|
if (is_partial_io(bvec)) {
|
|
memcpy(uncmem + offset, user_mem + bvec->bv_offset,
|
|
bvec->bv_len);
|
|
kunmap_atomic(user_mem);
|
|
user_mem = NULL;
|
|
} else {
|
|
uncmem = user_mem;
|
|
}
|
|
|
|
if (page_zero_filled(uncmem)) {
|
|
kunmap_atomic(user_mem);
|
|
/* Free memory associated with this sector now. */
|
|
write_lock(&zram->meta->tb_lock);
|
|
zram_free_page(zram, index);
|
|
zram_set_flag(meta, index, ZRAM_ZERO);
|
|
write_unlock(&zram->meta->tb_lock);
|
|
|
|
atomic_inc(&zram->stats.pages_zero);
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
|
|
meta->compress_workmem);
|
|
if (!is_partial_io(bvec)) {
|
|
kunmap_atomic(user_mem);
|
|
user_mem = NULL;
|
|
uncmem = NULL;
|
|
}
|
|
|
|
if (unlikely(ret != LZO_E_OK)) {
|
|
pr_err("Compression failed! err=%d\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(clen > max_zpage_size)) {
|
|
atomic_inc(&zram->stats.bad_compress);
|
|
clen = PAGE_SIZE;
|
|
src = NULL;
|
|
if (is_partial_io(bvec))
|
|
src = uncmem;
|
|
}
|
|
|
|
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(meta->mem_pool, handle, ZS_MM_WO);
|
|
|
|
if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) {
|
|
src = kmap_atomic(page);
|
|
copy_page(cmem, src);
|
|
kunmap_atomic(src);
|
|
} else {
|
|
memcpy(cmem, src, clen);
|
|
}
|
|
|
|
zs_unmap_object(meta->mem_pool, handle);
|
|
|
|
/*
|
|
* Free memory associated with this sector
|
|
* before overwriting unused sectors.
|
|
*/
|
|
write_lock(&zram->meta->tb_lock);
|
|
zram_free_page(zram, index);
|
|
|
|
meta->table[index].handle = handle;
|
|
meta->table[index].size = clen;
|
|
write_unlock(&zram->meta->tb_lock);
|
|
|
|
/* Update stats */
|
|
atomic64_add(clen, &zram->stats.compr_size);
|
|
atomic_inc(&zram->stats.pages_stored);
|
|
if (clen <= PAGE_SIZE / 2)
|
|
atomic_inc(&zram->stats.good_compress);
|
|
|
|
out:
|
|
if (locked)
|
|
mutex_unlock(&meta->buffer_lock);
|
|
if (is_partial_io(bvec))
|
|
kfree(uncmem);
|
|
|
|
if (ret)
|
|
atomic64_inc(&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)
|
|
ret = zram_bvec_read(zram, bvec, index, offset, bio);
|
|
else
|
|
ret = zram_bvec_write(zram, bvec, index, offset);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void zram_reset_device(struct zram *zram, bool reset_capacity)
|
|
{
|
|
size_t index;
|
|
struct zram_meta *meta;
|
|
|
|
down_write(&zram->init_lock);
|
|
if (!zram->init_done) {
|
|
up_write(&zram->init_lock);
|
|
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;
|
|
if (reset_capacity)
|
|
set_capacity(zram->disk, 0);
|
|
up_write(&zram->init_lock);
|
|
}
|
|
|
|
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);
|
|
|
|
if (!bdev)
|
|
return -ENOMEM;
|
|
|
|
/* Do not reset an active device! */
|
|
if (bdev->bd_holders) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ret = kstrtou16(buf, 10, &do_reset);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (!do_reset) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* Make sure all pending I/O is finished */
|
|
fsync_bdev(bdev);
|
|
bdput(bdev);
|
|
|
|
zram_reset_device(zram, true);
|
|
return len;
|
|
|
|
out:
|
|
bdput(bdev);
|
|
return ret;
|
|
}
|
|
|
|
static void __zram_make_request(struct zram *zram, struct bio *bio, int rw)
|
|
{
|
|
int offset;
|
|
u32 index;
|
|
struct bio_vec bvec;
|
|
struct bvec_iter iter;
|
|
|
|
switch (rw) {
|
|
case READ:
|
|
atomic64_inc(&zram->stats.num_reads);
|
|
break;
|
|
case WRITE:
|
|
atomic64_inc(&zram->stats.num_writes);
|
|
break;
|
|
}
|
|
|
|
index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
|
|
offset = (bio->bi_iter.bi_sector &
|
|
(SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
|
|
|
|
bio_for_each_segment(bvec, bio, iter) {
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* Handler function for all zram I/O requests.
|
|
*/
|
|
static void zram_make_request(struct request_queue *queue, struct bio *bio)
|
|
{
|
|
struct zram *zram = queue->queuedata;
|
|
|
|
down_read(&zram->init_lock);
|
|
if (unlikely(!zram->init_done))
|
|
goto error;
|
|
|
|
if (!valid_io_request(zram, bio)) {
|
|
atomic64_inc(&zram->stats.invalid_io);
|
|
goto error;
|
|
}
|
|
|
|
__zram_make_request(zram, bio, bio_data_dir(bio));
|
|
up_read(&zram->init_lock);
|
|
|
|
return;
|
|
|
|
error:
|
|
up_read(&zram->init_lock);
|
|
bio_io_error(bio);
|
|
}
|
|
|
|
static void zram_slot_free_notify(struct block_device *bdev,
|
|
unsigned long index)
|
|
{
|
|
struct zram *zram;
|
|
struct zram_meta *meta;
|
|
|
|
zram = bdev->bd_disk->private_data;
|
|
meta = zram->meta;
|
|
|
|
write_lock(&meta->tb_lock);
|
|
zram_free_page(zram, index);
|
|
write_unlock(&meta->tb_lock);
|
|
atomic64_inc(&zram->stats.notify_free);
|
|
}
|
|
|
|
static const struct block_device_operations zram_devops = {
|
|
.swap_slot_free_notify = zram_slot_free_notify,
|
|
.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 = -ENOMEM;
|
|
|
|
init_rwsem(&zram->init_lock);
|
|
|
|
zram->queue = blk_alloc_queue(GFP_KERNEL);
|
|
if (!zram->queue) {
|
|
pr_err("Error allocating disk queue for device %d\n",
|
|
device_id);
|
|
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) {
|
|
pr_warn("Error allocating disk structure for device %d\n",
|
|
device_id);
|
|
goto out_free_queue;
|
|
}
|
|
|
|
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_warn("Error creating sysfs group");
|
|
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;
|
|
}
|
|
|
|
static void destroy_device(struct zram *zram)
|
|
{
|
|
sysfs_remove_group(&disk_to_dev(zram->disk)->kobj,
|
|
&zram_disk_attr_group);
|
|
|
|
del_gendisk(zram->disk);
|
|
put_disk(zram->disk);
|
|
|
|
blk_cleanup_queue(zram->queue);
|
|
}
|
|
|
|
static int __init zram_init(void)
|
|
{
|
|
int ret, dev_id;
|
|
|
|
if (num_devices > max_num_devices) {
|
|
pr_warn("Invalid value for num_devices: %u\n",
|
|
num_devices);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
zram_major = register_blkdev(0, "zram");
|
|
if (zram_major <= 0) {
|
|
pr_warn("Unable to get major number\n");
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
/* Allocate the device array and initialize each one */
|
|
zram_devices = kzalloc(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(&zram_devices[dev_id], dev_id);
|
|
if (ret)
|
|
goto free_devices;
|
|
}
|
|
|
|
pr_info("Created %u device(s) ...\n", num_devices);
|
|
|
|
return 0;
|
|
|
|
free_devices:
|
|
while (dev_id)
|
|
destroy_device(&zram_devices[--dev_id]);
|
|
kfree(zram_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 = &zram_devices[i];
|
|
|
|
destroy_device(zram);
|
|
/*
|
|
* Shouldn't access zram->disk after destroy_device
|
|
* because destroy_device already released zram->disk.
|
|
*/
|
|
zram_reset_device(zram, false);
|
|
}
|
|
|
|
unregister_blkdev(zram_major, "zram");
|
|
|
|
kfree(zram_devices);
|
|
pr_debug("Cleanup done!\n");
|
|
}
|
|
|
|
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");
|