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zram: refactor flags and writeback stuff

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Rename some variables and restructure some code for better readability in
writeback and zs_free_page.

Link: http://lkml.kernel.org/r/20181127055429.251614-4-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Minchan Kim 2018-12-28 00:36:40 -08:00 committed by Linus Torvalds
parent 5547932dc6
commit 7e5292831b
2 changed files with 44 additions and 69 deletions
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105
drivers/block/zram/zram_drv.c
View file

@ -55,17 +55,17 @@ static void zram_free_page(struct zram *zram, size_t index);
static int zram_slot_trylock(struct zram *zram, u32 index)
{
return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].value);
return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags);
}
static void zram_slot_lock(struct zram *zram, u32 index)
{
bit_spin_lock(ZRAM_LOCK, &zram->table[index].value);
bit_spin_lock(ZRAM_LOCK, &zram->table[index].flags);
}
static void zram_slot_unlock(struct zram *zram, u32 index)
{
bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value);
bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags);
}
static inline bool init_done(struct zram *zram)
@ -76,7 +76,7 @@ static inline bool init_done(struct zram *zram)
static inline bool zram_allocated(struct zram *zram, u32 index)
{
return (zram->table[index].value >> (ZRAM_FLAG_SHIFT + 1)) ||
return (zram->table[index].flags >> (ZRAM_FLAG_SHIFT + 1)) ||
zram->table[index].handle;
}
@ -99,19 +99,19 @@ static void zram_set_handle(struct zram *zram, u32 index, unsigned long handle)
static bool zram_test_flag(struct zram *zram, u32 index,
enum zram_pageflags flag)
{
return zram->table[index].value & BIT(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].value |= BIT(flag);
zram->table[index].flags |= BIT(flag);
}
static void zram_clear_flag(struct zram *zram, u32 index,
enum zram_pageflags flag)
{
zram->table[index].value &= ~BIT(flag);
zram->table[index].flags &= ~BIT(flag);
}
static inline void zram_set_element(struct zram *zram, u32 index,
@ -127,15 +127,15 @@ static unsigned long zram_get_element(struct zram *zram, u32 index)
static size_t zram_get_obj_size(struct zram *zram, u32 index)
{
return zram->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1);
return zram->table[index].flags & (BIT(ZRAM_FLAG_SHIFT) - 1);
}
static void zram_set_obj_size(struct zram *zram,
u32 index, size_t size)
{
unsigned long flags = zram->table[index].value >> ZRAM_FLAG_SHIFT;
unsigned long flags = zram->table[index].flags >> ZRAM_FLAG_SHIFT;
zram->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
zram->table[index].flags = (flags << ZRAM_FLAG_SHIFT) | size;
}
#if PAGE_SIZE != 4096
@ -282,16 +282,11 @@ static ssize_t mem_used_max_store(struct device *dev,
}
#ifdef CONFIG_ZRAM_WRITEBACK
static bool zram_wb_enabled(struct zram *zram)
{
return zram->backing_dev;
}
static void reset_bdev(struct zram *zram)
{
struct block_device *bdev;
if (!zram_wb_enabled(zram))
if (!zram->backing_dev)
return;
bdev = zram->bdev;
@ -318,7 +313,7 @@ static ssize_t backing_dev_show(struct device *dev,
ssize_t ret;
down_read(&zram->init_lock);
if (!zram_wb_enabled(zram)) {
if (!zram->backing_dev) {
memcpy(buf, "none\n", 5);
up_read(&zram->init_lock);
return 5;
@ -447,7 +442,7 @@ out:
return err;
}
static unsigned long get_entry_bdev(struct zram *zram)
static unsigned long alloc_block_bdev(struct zram *zram)
{
unsigned long blk_idx = 1;
retry:
@ -462,11 +457,11 @@ retry:
return blk_idx;
}
static void put_entry_bdev(struct zram *zram, unsigned long entry)
static void free_block_bdev(struct zram *zram, unsigned long blk_idx)
{
int was_set;
was_set = test_and_clear_bit(entry, zram->bitmap);
was_set = test_and_clear_bit(blk_idx, zram->bitmap);
WARN_ON_ONCE(!was_set);
}
@ -579,7 +574,7 @@ static int write_to_bdev(struct zram *zram, struct bio_vec *bvec,
if (!bio)
return -ENOMEM;
entry = get_entry_bdev(zram);
entry = alloc_block_bdev(zram);
if (!entry) {
bio_put(bio);
return -ENOSPC;
@ -590,7 +585,7 @@ static int write_to_bdev(struct zram *zram, struct bio_vec *bvec,
if (!bio_add_page(bio, bvec->bv_page, bvec->bv_len,
bvec->bv_offset)) {
bio_put(bio);
put_entry_bdev(zram, entry);
free_block_bdev(zram, entry);
return -EIO;
}
@ -608,18 +603,7 @@ static int write_to_bdev(struct zram *zram, struct bio_vec *bvec,
return 0;
}
static void zram_wb_clear(struct zram *zram, u32 index)
{
unsigned long entry;
zram_clear_flag(zram, index, ZRAM_WB);
entry = zram_get_element(zram, index);
zram_set_element(zram, index, 0);
put_entry_bdev(zram, entry);
}
#else
static bool zram_wb_enabled(struct zram *zram) { return false; }
static inline void reset_bdev(struct zram *zram) {};
static int write_to_bdev(struct zram *zram, struct bio_vec *bvec,
u32 index, struct bio *parent,
@ -634,7 +618,8 @@ static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
{
return -EIO;
}
static void zram_wb_clear(struct zram *zram, u32 index) {}
static void free_block_bdev(struct zram *zram, unsigned long blk_idx) {};
#endif
#ifdef CONFIG_ZRAM_MEMORY_TRACKING
@ -656,11 +641,6 @@ static void zram_accessed(struct zram *zram, u32 index)
zram->table[index].ac_time = ktime_get_boottime();
}
static void zram_reset_access(struct zram *zram, u32 index)
{
zram->table[index].ac_time = 0;
}
static ssize_t read_block_state(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
@ -741,7 +721,6 @@ static void zram_debugfs_unregister(struct zram *zram)
static void zram_debugfs_create(void) {};
static void zram_debugfs_destroy(void) {};
static void zram_accessed(struct zram *zram, u32 index) {};
static void zram_reset_access(struct zram *zram, u32 index) {};
static void zram_debugfs_register(struct zram *zram) {};
static void zram_debugfs_unregister(struct zram *zram) {};
#endif
@ -942,17 +921,18 @@ static void zram_free_page(struct zram *zram, size_t index)
{
unsigned long handle;
zram_reset_access(zram, index);
#ifdef CONFIG_ZRAM_MEMORY_TRACKING
zram->table[index].ac_time = 0;
#endif
if (zram_test_flag(zram, index, ZRAM_HUGE)) {
zram_clear_flag(zram, index, ZRAM_HUGE);
atomic64_dec(&zram->stats.huge_pages);
}
if (zram_wb_enabled(zram) && zram_test_flag(zram, index, ZRAM_WB)) {
zram_wb_clear(zram, index);
atomic64_dec(&zram->stats.pages_stored);
return;
if (zram_test_flag(zram, index, ZRAM_WB)) {
zram_clear_flag(zram, index, ZRAM_WB);
free_block_bdev(zram, zram_get_element(zram, index));
goto out;
}
/*
@ -961,10 +941,8 @@ static void zram_free_page(struct zram *zram, size_t index)
*/
if (zram_test_flag(zram, index, ZRAM_SAME)) {
zram_clear_flag(zram, index, ZRAM_SAME);
zram_set_element(zram, index, 0);
atomic64_dec(&zram->stats.same_pages);
atomic64_dec(&zram->stats.pages_stored);
return;
goto out;
}
handle = zram_get_handle(zram, index);
@ -975,10 +953,11 @@ static void zram_free_page(struct zram *zram, size_t index)
atomic64_sub(zram_get_obj_size(zram, index),
&zram->stats.compr_data_size);
out:
atomic64_dec(&zram->stats.pages_stored);
zram_set_handle(zram, index, 0);
zram_set_obj_size(zram, index, 0);
WARN_ON_ONCE(zram->table[index].flags & ~(1UL << ZRAM_LOCK));
}
static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
@ -989,24 +968,20 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
unsigned int size;
void *src, *dst;
if (zram_wb_enabled(zram)) {
zram_slot_lock(zram, index);
if (zram_test_flag(zram, index, ZRAM_WB)) {
struct bio_vec bvec;
zram_slot_lock(zram, index);
if (zram_test_flag(zram, index, ZRAM_WB)) {
struct bio_vec bvec;
zram_slot_unlock(zram, index);
bvec.bv_page = page;
bvec.bv_len = PAGE_SIZE;
bvec.bv_offset = 0;
return read_from_bdev(zram, &bvec,
zram_get_element(zram, index),
bio, partial_io);
}
zram_slot_unlock(zram, index);
bvec.bv_page = page;
bvec.bv_len = PAGE_SIZE;
bvec.bv_offset = 0;
return read_from_bdev(zram, &bvec,
zram_get_element(zram, index),
bio, partial_io);
}
zram_slot_lock(zram, index);
handle = zram_get_handle(zram, index);
if (!handle || zram_test_flag(zram, index, ZRAM_SAME)) {
unsigned long value;
@ -1118,7 +1093,7 @@ compress_again:
if (unlikely(comp_len >= huge_class_size)) {
comp_len = PAGE_SIZE;
if (zram_wb_enabled(zram) && allow_wb) {
if (zram->backing_dev && allow_wb) {
zcomp_stream_put(zram->comp);
ret = write_to_bdev(zram, bvec, index, bio, &element);
if (!ret) {

8
drivers/block/zram/zram_drv.h
View file

@ -30,7 +30,7 @@
/*
* The lower ZRAM_FLAG_SHIFT bits of table.value is for
* The lower ZRAM_FLAG_SHIFT bits of table.flags is for
* object size (excluding header), the higher bits is for
* zram_pageflags.
*
@ -41,7 +41,7 @@
*/
#define ZRAM_FLAG_SHIFT 24
/* Flags for zram pages (table[page_no].value) */
/* Flags for zram pages (table[page_no].flags) */
enum zram_pageflags {
/* zram slot is locked */
ZRAM_LOCK = ZRAM_FLAG_SHIFT,
@ -60,7 +60,7 @@ struct zram_table_entry {
unsigned long handle;
unsigned long element;
};
unsigned long value;
unsigned long flags;
#ifdef CONFIG_ZRAM_MEMORY_TRACKING
ktime_t ac_time;
#endif
@ -105,8 +105,8 @@ struct zram {
* zram is claimed so open request will be failed
*/
bool claim; /* Protected by bdev->bd_mutex */
#ifdef CONFIG_ZRAM_WRITEBACK
struct file *backing_dev;
#ifdef CONFIG_ZRAM_WRITEBACK
struct block_device *bdev;
unsigned int old_block_size;
unsigned long *bitmap;