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Commit 4200a93e authored by Minchan Kim's avatar Minchan Kim Committed by Srinivas Paladugu
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UPSTREAM: zram: refactor flags and writeback stuff 

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: default avatarMinchan Kim <minchan@kernel.org>
Reviewed-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: default avatarJoey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 7e5292831b346bacb05558ca385cae366187314c)

Bug: 117683045
Change-Id: I4ff293133bbd2a6d43a4860220904c08bb381bd0
Signed-off-by: default avatarSrinivas Paladugu <srnvs@google.com>
parent 0c3de481

drivers/block/zram/zram_drv.c

+40 −65
Original line number Diff line number Diff line
@@ -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 @@ static ssize_t backing_dev_store(struct device *dev, 
	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 @@ static unsigned long get_entry_bdev(struct zram *zram) 
	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,
@@ -989,7 +968,6 @@ 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;
@@ -1003,10 +981,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, 
				zram_get_element(zram, index),

				bio, partial_io);

	}

		zram_slot_unlock(zram, index);

	}



	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 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, 


	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) {

drivers/block/zram/zram_drv.h

+4 −4
Original line number Diff line number Diff line
@@ -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;