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Commit 522698d7 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Linus Torvalds
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zram: reorganize code layout 

This patch looks big, but basically it just moves code blocks.
No functional changes.

Our current code layout looks like a sandwitch.

For example,
a) between read/write handlers, we have update_used_max() helper function:

static int zram_decompress_page
static int zram_bvec_read
static inline void update_used_max
static int zram_bvec_write
static int zram_bvec_rw

b) RW request handlers __zram_make_request/zram_bio_discard are divided by
sysfs attr reset_store() function and corresponding zram_reset_device()
handler:

static void zram_bio_discard
static void zram_reset_device
static ssize_t disksize_store
static ssize_t reset_store
static void __zram_make_request

c) we first a bunch of sysfs read/store functions. then a number of
one-liners, then helper functions, RW functions, sysfs functions, helper
functions again, and so on.

Reorganize layout to be more logically grouped (a brief description,
`cat zram_drv.c | grep static` gives a bigger picture):

-- one-liners: zram_test_flag/etc.

-- helpers: is_partial_io/update_position/etc

-- sysfs attr show/store functions + ZRAM_ATTR_RO() generated stats
show() functions
exception: reset and disksize store functions are required to be after
meta() functions. because we do device create/destroy actions in these
sysfs handlers.

-- "mm" functions: meta get/put, meta alloc/free, page free
static inline bool zram_meta_get
static inline void zram_meta_put
static void zram_meta_free
static struct zram_meta *zram_meta_alloc
static void zram_free_page

-- a block of I/O functions
static int zram_decompress_page
static int zram_bvec_read
static int zram_bvec_write
static void zram_bio_discard
static int zram_bvec_rw
static void __zram_make_request
static void zram_make_request
static void zram_slot_free_notify
static int zram_rw_page

-- device contol: add/remove/init/reset functions (+zram-control class
will sit here)
static int zram_reset_device
static ssize_t reset_store
static ssize_t disksize_store
static int zram_add
static void zram_remove
static int __init zram_init
static void __exit zram_exit
Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 85508ec6
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Inline Side-by-side
Showing with 368 additions and 369 deletions
drivers/block/zram/zram_drv.c
View file @ 522698d7
......@@ -70,33 +70,117 @@ static inline struct zram *dev_to_zram(struct device *dev)
return (struct zram *)dev_to_disk(dev)->private_data;
}
static ssize_t compact_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
/* flag operations needs meta->tb_lock */
static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
unsigned long nr_migrated;
struct zram *zram = dev_to_zram(dev);
struct zram_meta *meta;
return meta->table[index].value & BIT(flag);
}
down_read(&zram->init_lock);
if (!init_done(zram)) {
up_read(&zram->init_lock);
return -EINVAL;
}
static void zram_set_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
meta->table[index].value |= BIT(flag);
}
meta = zram->meta;
nr_migrated = zs_compact(meta->mem_pool);
atomic64_add(nr_migrated, &zram->stats.num_migrated);
up_read(&zram->init_lock);
static void zram_clear_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
meta->table[index].value &= ~BIT(flag);
}
return len;
static size_t zram_get_obj_size(struct zram_meta *meta, u32 index)
{
return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1);
}
static ssize_t disksize_show(struct device *dev,
struct device_attribute *attr, char *buf)
static void zram_set_obj_size(struct zram_meta *meta,
u32 index, size_t size)
{
struct zram *zram = dev_to_zram(dev);
unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT;
return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize);
meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
}
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,
sector_t start, unsigned int size)
{
u64 end, bound;
/* unaligned request */
if (unlikely(start & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)))
return 0;
if (unlikely(size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))
return 0;
end = start + (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 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 inline void update_used_max(struct zram *zram,
const unsigned long pages)
{
unsigned long old_max, cur_max;
old_max = atomic_long_read(&zram->stats.max_used_pages);
do {
cur_max = old_max;
if (pages > cur_max)
old_max = atomic_long_cmpxchg(
&zram->stats.max_used_pages, cur_max, pages);
} while (old_max != cur_max);
}
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);
}
static ssize_t initstate_show(struct device *dev,
......@@ -112,6 +196,14 @@ static ssize_t initstate_show(struct device *dev,
return scnprintf(buf, PAGE_SIZE, "%u\n", val);
}
static ssize_t disksize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct zram *zram = dev_to_zram(dev);
return scnprintf(buf, PAGE_SIZE, "%llu\n", zram->disksize);
}
static ssize_t orig_data_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
......@@ -139,19 +231,6 @@ static ssize_t mem_used_total_show(struct device *dev,
return scnprintf(buf, PAGE_SIZE, "%llu\n", val << PAGE_SHIFT);
}
static ssize_t max_comp_streams_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int val;
struct zram *zram = dev_to_zram(dev);
down_read(&zram->init_lock);
val = zram->max_comp_streams;
up_read(&zram->init_lock);
return scnprintf(buf, PAGE_SIZE, "%d\n", val);
}
static ssize_t mem_limit_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
......@@ -221,6 +300,19 @@ static ssize_t mem_used_max_store(struct device *dev,
return len;
}
static ssize_t max_comp_streams_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int val;
struct zram *zram = dev_to_zram(dev);
down_read(&zram->init_lock);
val = zram->max_comp_streams;
up_read(&zram->init_lock);
return scnprintf(buf, PAGE_SIZE, "%d\n", val);
}
static ssize_t max_comp_streams_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
......@@ -278,71 +370,101 @@ static ssize_t comp_algorithm_store(struct device *dev,
return len;
}
/* flag operations needs meta->tb_lock */
static int zram_test_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
static ssize_t compact_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
return meta->table[index].value & BIT(flag);
}
unsigned long nr_migrated;
struct zram *zram = dev_to_zram(dev);
struct zram_meta *meta;
static void zram_set_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
meta->table[index].value |= BIT(flag);
}
down_read(&zram->init_lock);
if (!init_done(zram)) {
up_read(&zram->init_lock);
return -EINVAL;
}
static void zram_clear_flag(struct zram_meta *meta, u32 index,
enum zram_pageflags flag)
{
meta->table[index].value &= ~BIT(flag);
}
meta = zram->meta;
nr_migrated = zs_compact(meta->mem_pool);
atomic64_add(nr_migrated, &zram->stats.num_migrated);
up_read(&zram->init_lock);
static size_t zram_get_obj_size(struct zram_meta *meta, u32 index)
{
return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1);
return len;
}
static void zram_set_obj_size(struct zram_meta *meta,
u32 index, size_t size)
static ssize_t io_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT;
struct zram *zram = dev_to_zram(dev);
ssize_t ret;
meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
}
down_read(&zram->init_lock);
ret = scnprintf(buf, PAGE_SIZE,
"%8llu %8llu %8llu %8llu\n",
(u64)atomic64_read(&zram->stats.failed_reads),
(u64)atomic64_read(&zram->stats.failed_writes),
(u64)atomic64_read(&zram->stats.invalid_io),
(u64)atomic64_read(&zram->stats.notify_free));
up_read(&zram->init_lock);
static inline int is_partial_io(struct bio_vec *bvec)
{
return bvec->bv_len != PAGE_SIZE;
return ret;
}
/*
* Check if request is within bounds and aligned on zram logical blocks.
*/
static inline int valid_io_request(struct zram *zram,
sector_t start, unsigned int size)
static ssize_t mm_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
u64 end, bound;
struct zram *zram = dev_to_zram(dev);
u64 orig_size, mem_used = 0;
long max_used;
ssize_t ret;
/* unaligned request */
if (unlikely(start & (ZRAM_SECTOR_PER_LOGICAL_BLOCK - 1)))
return 0;
if (unlikely(size & (ZRAM_LOGICAL_BLOCK_SIZE - 1)))
return 0;
down_read(&zram->init_lock);
if (init_done(zram))
mem_used = zs_get_total_pages(zram->meta->mem_pool);
end = start + (size >> SECTOR_SHIFT);
bound = zram->disksize >> SECTOR_SHIFT;
/* out of range range */
if (unlikely(start >= bound || end > bound || start > end))
return 0;
orig_size = atomic64_read(&zram->stats.pages_stored);
max_used = atomic_long_read(&zram->stats.max_used_pages);
/* I/O request is valid */
return 1;
}
ret = scnprintf(buf, PAGE_SIZE,
"%8llu %8llu %8llu %8lu %8ld %8llu %8llu\n",
orig_size << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.compr_data_size),
mem_used << PAGE_SHIFT,
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.zero_pages),
(u64)atomic64_read(&zram->stats.num_migrated));
up_read(&zram->init_lock);
static void zram_meta_free(struct zram_meta *meta, u64 disksize)
{
size_t num_pages = disksize >> PAGE_SHIFT;
size_t index;
return ret;
}
static DEVICE_ATTR_RO(io_stat);
static DEVICE_ATTR_RO(mm_stat);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
ZRAM_ATTR_RO(failed_reads);
ZRAM_ATTR_RO(failed_writes);
ZRAM_ATTR_RO(invalid_io);
ZRAM_ATTR_RO(notify_free);
ZRAM_ATTR_RO(zero_pages);
ZRAM_ATTR_RO(compr_data_size);
static inline bool zram_meta_get(struct zram *zram)
{
if (atomic_inc_not_zero(&zram->refcount))
return true;
return false;
}
static inline void zram_meta_put(struct zram *zram)
{
atomic_dec(&zram->refcount);
}
static void zram_meta_free(struct zram_meta *meta, u64 disksize)
{
size_t num_pages = disksize >> PAGE_SHIFT;
size_t index;
/* Free all pages that are still in this zram device */
for (index = 0; index < num_pages; index++) {
......@@ -390,56 +512,6 @@ static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize)
return NULL;
}
static inline bool zram_meta_get(struct zram *zram)
{
if (atomic_inc_not_zero(&zram->refcount))
return true;
return false;
}
static inline void zram_meta_put(struct zram *zram)
{
atomic_dec(&zram->refcount);
}
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);
}
/*
* To protect concurrent access to the same index entry,
* caller should hold this table index entry's bit_spinlock to
......@@ -557,21 +629,6 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
return ret;
}
static inline void update_used_max(struct zram *zram,
const unsigned long pages)
{
unsigned long old_max, cur_max;
old_max = atomic_long_read(&zram->stats.max_used_pages);
do {
cur_max = old_max;
if (pages > cur_max)
old_max = atomic_long_cmpxchg(
&zram->stats.max_used_pages, cur_max, pages);
} while (old_max != cur_max);
}
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset)
{
......@@ -699,6 +756,45 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
return ret;
}
/*
* zram_bio_discard - handler on discard request
* @index: physical block index in PAGE_SIZE units
* @offset: byte offset within physical block
*/
static void zram_bio_discard(struct zram *zram, u32 index,
int offset, struct bio *bio)
{
size_t n = bio->bi_iter.bi_size;
struct zram_meta *meta = zram->meta;
/*
* zram manages data in physical block size units. Because logical block
* size isn't identical with physical block size on some arch, we
* could get a discard request pointing to a specific offset within a
* certain physical block. Although we can handle this request by
* reading that physiclal block and decompressing and partially zeroing
* and re-compressing and then re-storing it, this isn't reasonable
* because our intent with a discard request is to save memory. So
* skipping this logical block is appropriate here.
*/
if (offset) {
if (n <= (PAGE_SIZE - offset))
return;
n -= (PAGE_SIZE - offset);
index++;
}
while (n >= PAGE_SIZE) {
bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
zram_free_page(zram, index);
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
atomic64_inc(&zram->stats.notify_free);
index++;
n -= PAGE_SIZE;
}
}
static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset, int rw)
{
......@@ -728,43 +824,140 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
return ret;
}
/*
* zram_bio_discard - handler on discard request
* @index: physical block index in PAGE_SIZE units
* @offset: byte offset within physical block
*/
static void zram_bio_discard(struct zram *zram, u32 index,
int offset, struct bio *bio)
static void __zram_make_request(struct zram *zram, struct bio *bio)
{
size_t n = bio->bi_iter.bi_size;
struct zram_meta *meta = zram->meta;
int offset, rw;
u32 index;
struct bio_vec bvec;
struct bvec_iter iter;
index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
offset = (bio->bi_iter.bi_sector &
(SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
if (unlikely(bio->bi_rw & REQ_DISCARD)) {
zram_bio_discard(zram, index, offset, bio);
bio_endio(bio, 0);
return;
}
rw = bio_data_dir(bio);
bio_for_each_segment(bvec, bio, iter) {
int max_transfer_size = PAGE_SIZE - offset;
if (bvec.bv_len > max_transfer_size) {
/*
* zram manages data in physical block size units. Because logical block
* size isn't identical with physical block size on some arch, we
* could get a discard request pointing to a specific offset within a
* certain physical block. Although we can handle this request by
* reading that physiclal block and decompressing and partially zeroing
* and re-compressing and then re-storing it, this isn't reasonable
* because our intent with a discard request is to save memory. So
* skipping this logical block is appropriate here.
* zram_bvec_rw() can only make operation on a single
* zram page. Split the bio vector.
*/
if (offset) {
if (n <= (PAGE_SIZE - offset))
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, 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, rw) < 0)
goto out;
} else
if (zram_bvec_rw(zram, &bvec, index, offset, rw) < 0)
goto out;
update_position(&index, &offset, &bvec);
}
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
return;
n -= (PAGE_SIZE - offset);
index++;
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;
if (unlikely(!zram_meta_get(zram)))
goto error;
if (!valid_io_request(zram, bio->bi_iter.bi_sector,
bio->bi_iter.bi_size)) {
atomic64_inc(&zram->stats.invalid_io);
goto put_zram;
}
while (n >= PAGE_SIZE) {
__zram_make_request(zram, bio);
zram_meta_put(zram);
return;
put_zram:
zram_meta_put(zram);
error:
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;
bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
zram_free_page(zram, index);
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
atomic64_inc(&zram->stats.notify_free);
index++;
n -= PAGE_SIZE;
}
static int zram_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, int rw)
{
int offset, err = -EIO;
u32 index;
struct zram *zram;
struct bio_vec bv;
zram = bdev->bd_disk->private_data;
if (unlikely(!zram_meta_get(zram)))
goto out;
if (!valid_io_request(zram, sector, PAGE_SIZE)) {
atomic64_inc(&zram->stats.invalid_io);
err = -EINVAL;
goto put_zram;
}
index = sector >> SECTORS_PER_PAGE_SHIFT;
offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
bv.bv_page = page;
bv.bv_len = PAGE_SIZE;
bv.bv_offset = 0;
err = zram_bvec_rw(zram, &bv, index, offset, rw);
put_zram:
zram_meta_put(zram);
out:
/*
* If I/O fails, just return error(ie, non-zero) without
* calling page_endio.
* It causes resubmit the I/O with bio request by upper functions
* of rw_page(e.g., swap_readpage, __swap_writepage) and
* bio->bi_end_io does things to handle the error
* (e.g., SetPageError, set_page_dirty and extra works).
*/
if (err == 0)
page_endio(page, rw, 0);
return err;
}
static void zram_reset_device(struct zram *zram)
......@@ -915,142 +1108,6 @@ static ssize_t reset_store(struct device *dev,
return ret;
}
static void __zram_make_request(struct zram *zram, struct bio *bio)
{
int offset, rw;
u32 index;
struct bio_vec bvec;
struct bvec_iter iter;
index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
offset = (bio->bi_iter.bi_sector &
(SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
if (unlikely(bio->bi_rw & REQ_DISCARD)) {
zram_bio_discard(zram, index, offset, bio);
bio_endio(bio, 0);
return;
}
rw = bio_data_dir(bio);
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, 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, rw) < 0)
goto out;
} else
if (zram_bvec_rw(zram, &bvec, index, offset, 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;
if (unlikely(!zram_meta_get(zram)))
goto error;
if (!valid_io_request(zram, bio->bi_iter.bi_sector,
bio->bi_iter.bi_size)) {
atomic64_inc(&zram->stats.invalid_io);
goto put_zram;
}
__zram_make_request(zram, bio);
zram_meta_put(zram);
return;
put_zram:
zram_meta_put(zram);
error:
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;
bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
zram_free_page(zram, index);
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
atomic64_inc(&zram->stats.notify_free);
}
static int zram_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, int rw)
{
int offset, err = -EIO;
u32 index;
struct zram *zram;
struct bio_vec bv;
zram = bdev->bd_disk->private_data;
if (unlikely(!zram_meta_get(zram)))
goto out;
if (!valid_io_request(zram, sector, PAGE_SIZE)) {
atomic64_inc(&zram->stats.invalid_io);
err = -EINVAL;
goto put_zram;
}
index = sector >> SECTORS_PER_PAGE_SHIFT;
offset = sector & (SECTORS_PER_PAGE - 1) << SECTOR_SHIFT;
bv.bv_page = page;
bv.bv_len = PAGE_SIZE;
bv.bv_offset = 0;
err = zram_bvec_rw(zram, &bv, index, offset, rw);
put_zram:
zram_meta_put(zram);
out:
/*
* If I/O fails, just return error(ie, non-zero) without
* calling page_endio.
* It causes resubmit the I/O with bio request by upper functions
* of rw_page(e.g., swap_readpage, __swap_writepage) and
* bio->bi_end_io does things to handle the error
* (e.g., SetPageError, set_page_dirty and extra works).
*/
if (err == 0)
page_endio(page, rw, 0);
return err;
}
static const struct block_device_operations zram_devops = {
.swap_slot_free_notify = zram_slot_free_notify,
.rw_page = zram_rw_page,
......@@ -1068,64 +1125,6 @@ static DEVICE_ATTR_RW(mem_used_max);
static DEVICE_ATTR_RW(max_comp_streams);
static DEVICE_ATTR_RW(comp_algorithm);
static ssize_t io_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct zram *zram = dev_to_zram(dev);
ssize_t ret;
down_read(&zram->init_lock);
ret = scnprintf(buf, PAGE_SIZE,
"%8llu %8llu %8llu %8llu\n",
(u64)atomic64_read(&zram->stats.failed_reads),
(u64)atomic64_read(&zram->stats.failed_writes),
(u64)atomic64_read(&zram->stats.invalid_io),
(u64)atomic64_read(&zram->stats.notify_free));
up_read(&zram->init_lock);
return ret;
}
static ssize_t mm_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct zram *zram = dev_to_zram(dev);
u64 orig_size, mem_used = 0;
long max_used;
ssize_t ret;
down_read(&zram->init_lock);
if (init_done(zram))
mem_used = zs_get_total_pages(zram->meta->mem_pool);
orig_size = atomic64_read(&zram->stats.pages_stored);
max_used = atomic_long_read(&zram->stats.max_used_pages);
ret = scnprintf(buf, PAGE_SIZE,
"%8llu %8llu %8llu %8lu %8ld %8llu %8llu\n",
orig_size << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.compr_data_size),
mem_used << PAGE_SHIFT,
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.zero_pages),
(u64)atomic64_read(&zram->stats.num_migrated));
up_read(&zram->init_lock);
return ret;
}
static DEVICE_ATTR_RO(io_stat);
static DEVICE_ATTR_RO(mm_stat);
ZRAM_ATTR_RO(num_reads);
ZRAM_ATTR_RO(num_writes);
ZRAM_ATTR_RO(failed_reads);
ZRAM_ATTR_RO(failed_writes);
ZRAM_ATTR_RO(invalid_io);
ZRAM_ATTR_RO(notify_free);
ZRAM_ATTR_RO(zero_pages);
ZRAM_ATTR_RO(compr_data_size);
static struct attribute *zram_disk_attrs[] = {
&dev_attr_disksize.attr,
&dev_attr_initstate.attr,
......
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