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Groups > linux.kernel > #1614881 > unrolled thread

[PATCH 4/5] zram: remove zram_meta structure

Started byMinchan Kim <minchan@kernel.org>
First post2017-04-03 07:20 +0200
Last post2017-04-04 08:00 +0200
Articles 5 — 2 participants

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  [PATCH 4/5] zram: remove zram_meta structure Minchan Kim <minchan@kernel.org> - 2017-04-03 07:20 +0200
    Re: [PATCH 4/5] zram: remove zram_meta structure Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-04 04:40 +0200
      Re: [PATCH 4/5] zram: remove zram_meta structure Minchan Kim <minchan@kernel.org> - 2017-04-04 07:00 +0200
      Re: [PATCH 4/5] zram: remove zram_meta structure Minchan Kim <minchan@kernel.org> - 2017-04-04 07:50 +0200
        Re: [PATCH 4/5] zram: remove zram_meta structure Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-04 08:00 +0200

#1614881 — [PATCH 4/5] zram: remove zram_meta structure

FromMinchan Kim <minchan@kernel.org>
Date2017-04-03 07:20 +0200
Subject[PATCH 4/5] zram: remove zram_meta structure
Message-ID<ts2zg-2z9-1@gated-at.bofh.it>
It's redundant now. Instead, remove it and use zram structure
directly.

Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 drivers/block/zram/zram_drv.c | 163 +++++++++++++++++-------------------------
 drivers/block/zram/zram_drv.h |   6 +-
 2 files changed, 65 insertions(+), 104 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 71b0a584bc85..fdb73222841d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -58,46 +58,46 @@ static inline struct zram *dev_to_zram(struct device *dev)
 }
 
 /* flag operations require table entry bit_spin_lock() being held */
-static int zram_test_flag(struct zram_meta *meta, u32 index,
+static int zram_test_flag(struct zram *zram, u32 index,
 			enum zram_pageflags flag)
 {
-	return meta->table[index].value & BIT(flag);
+	return zram->table[index].value & BIT(flag);
 }
 
-static void zram_set_flag(struct zram_meta *meta, u32 index,
+static void zram_set_flag(struct zram *zram, u32 index,
 			enum zram_pageflags flag)
 {
-	meta->table[index].value |= BIT(flag);
+	zram->table[index].value |= BIT(flag);
 }
 
-static void zram_clear_flag(struct zram_meta *meta, u32 index,
+static void zram_clear_flag(struct zram *zram, u32 index,
 			enum zram_pageflags flag)
 {
-	meta->table[index].value &= ~BIT(flag);
+	zram->table[index].value &= ~BIT(flag);
 }
 
-static inline void zram_set_element(struct zram_meta *meta, u32 index,
+static inline void zram_set_element(struct zram *zram, u32 index,
 			unsigned long element)
 {
-	meta->table[index].element = element;
+	zram->table[index].element = element;
 }
 
-static inline void zram_clear_element(struct zram_meta *meta, u32 index)
+static inline void zram_clear_element(struct zram *zram, u32 index)
 {
-	meta->table[index].element = 0;
+	zram->table[index].element = 0;
 }
 
-static size_t zram_get_obj_size(struct zram_meta *meta, u32 index)
+static size_t zram_get_obj_size(struct zram *zram, u32 index)
 {
-	return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1);
+	return zram->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1);
 }
 
-static void zram_set_obj_size(struct zram_meta *meta,
+static void zram_set_obj_size(struct zram *zram,
 					u32 index, size_t size)
 {
-	unsigned long flags = meta->table[index].value >> ZRAM_FLAG_SHIFT;
+	unsigned long flags = zram->table[index].value >> ZRAM_FLAG_SHIFT;
 
-	meta->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
+	zram->table[index].value = (flags << ZRAM_FLAG_SHIFT) | size;
 }
 
 #if PAGE_SIZE != 4096
@@ -252,9 +252,8 @@ static ssize_t mem_used_max_store(struct device *dev,
 
 	down_read(&zram->init_lock);
 	if (init_done(zram)) {
-		struct zram_meta *meta = zram->meta;
 		atomic_long_set(&zram->stats.max_used_pages,
-				zs_get_total_pages(meta->mem_pool));
+				zs_get_total_pages(zram->mem_pool));
 	}
 	up_read(&zram->init_lock);
 
@@ -327,7 +326,6 @@ static ssize_t compact_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t len)
 {
 	struct zram *zram = dev_to_zram(dev);
-	struct zram_meta *meta;
 
 	down_read(&zram->init_lock);
 	if (!init_done(zram)) {
@@ -335,8 +333,7 @@ static ssize_t compact_store(struct device *dev,
 		return -EINVAL;
 	}
 
-	meta = zram->meta;
-	zs_compact(meta->mem_pool);
+	zs_compact(zram->mem_pool);
 	up_read(&zram->init_lock);
 
 	return len;
@@ -373,8 +370,8 @@ static ssize_t mm_stat_show(struct device *dev,
 
 	down_read(&zram->init_lock);
 	if (init_done(zram)) {
-		mem_used = zs_get_total_pages(zram->meta->mem_pool);
-		zs_pool_stats(zram->meta->mem_pool, &pool_stats);
+		mem_used = zs_get_total_pages(zram->mem_pool);
+		zs_pool_stats(zram->mem_pool, &pool_stats);
 	}
 
 	orig_size = atomic64_read(&zram->stats.pages_stored);
@@ -418,32 +415,26 @@ static DEVICE_ATTR_RO(debug_stat);
 
 static void zram_slot_lock(struct zram *zram, u32 index)
 {
-	struct zram_meta *meta = zram->meta;
-
-	bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
+	bit_spin_lock(ZRAM_ACCESS, &zram->table[index].value);
 }
 
 static void zram_slot_unlock(struct zram *zram, u32 index)
 {
-	struct zram_meta *meta = zram->meta;
-
-	bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
+	bit_spin_unlock(ZRAM_ACCESS, &zram->table[index].value);
 }
 
 static bool zram_special_page_read(struct zram *zram, u32 index,
 				struct page *page,
 				unsigned int offset, unsigned int len)
 {
-	struct zram_meta *meta = zram->meta;
-
 	zram_slot_lock(zram, index);
-	if (unlikely(!meta->table[index].handle) ||
-			zram_test_flag(meta, index, ZRAM_SAME)) {
+	if (unlikely(!zram->table[index].handle) ||
+			zram_test_flag(zram, index, ZRAM_SAME)) {
 		void *mem;
 
 		zram_slot_unlock(zram, index);
 		mem = kmap_atomic(page);
-		zram_fill_page(mem + offset, len, meta->table[index].element);
+		zram_fill_page(mem + offset, len, zram->table[index].element);
 		kunmap_atomic(mem);
 		return true;
 	}
@@ -459,14 +450,12 @@ static bool zram_special_page_write(struct zram *zram, u32 index,
 	void *mem = kmap_atomic(page);
 
 	if (page_same_filled(mem, &element)) {
-		struct zram_meta *meta = zram->meta;
-
 		kunmap_atomic(mem);
 		/* Free memory associated with this sector now. */
 		zram_slot_lock(zram, index);
 		zram_free_page(zram, index);
-		zram_set_flag(meta, index, ZRAM_SAME);
-		zram_set_element(meta, index, element);
+		zram_set_flag(zram, index, ZRAM_SAME);
+		zram_set_element(zram, index, element);
 		zram_slot_unlock(zram, index);
 
 		atomic64_inc(&zram->stats.same_pages);
@@ -477,56 +466,44 @@ static bool zram_special_page_write(struct zram *zram, u32 index,
 	return false;
 }
 
-static void zram_meta_free(struct zram_meta *meta, u64 disksize)
+static void zram_meta_free(struct zram *zram, 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++) {
-		unsigned long handle = meta->table[index].handle;
+		unsigned long handle = zram->table[index].handle;
 		/*
 		 * No memory is allocated for same element filled pages.
 		 * Simply clear same page flag.
 		 */
-		if (!handle || zram_test_flag(meta, index, ZRAM_SAME))
+		if (!handle || zram_test_flag(zram, index, ZRAM_SAME))
 			continue;
 
-		zs_free(meta->mem_pool, handle);
+		zs_free(zram->mem_pool, handle);
 	}
 
-	zs_destroy_pool(meta->mem_pool);
-	vfree(meta->table);
-	kfree(meta);
+	zs_destroy_pool(zram->mem_pool);
+	vfree(zram->table);
 }
 
-static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
+static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 {
 	size_t num_pages;
-	struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
-
-	if (!meta)
-		return NULL;
 
 	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 out_error;
-	}
+	zram->table = vzalloc(num_pages * sizeof(*zram->table));
+	if (!zram->table)
+		return false;
 
-	meta->mem_pool = zs_create_pool(pool_name);
-	if (!meta->mem_pool) {
-		pr_err("Error creating memory pool\n");
-		goto out_error;
+	zram->mem_pool = zs_create_pool(zram->disk->disk_name);
+	if (!zram->mem_pool) {
+		vfree(zram->table);
+		return false;
 	}
 
-	return meta;
-
-out_error:
-	vfree(meta->table);
-	kfree(meta);
-	return NULL;
+	return true;
 }
 
 /*
@@ -536,16 +513,15 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
  */
 static void zram_free_page(struct zram *zram, size_t index)
 {
-	struct zram_meta *meta = zram->meta;
-	unsigned long handle = meta->table[index].handle;
+	unsigned long handle = zram->table[index].handle;
 
 	/*
 	 * No memory is allocated for same element filled pages.
 	 * Simply clear same page flag.
 	 */
-	if (zram_test_flag(meta, index, ZRAM_SAME)) {
-		zram_clear_flag(meta, index, ZRAM_SAME);
-		zram_clear_element(meta, index);
+	if (zram_test_flag(zram, index, ZRAM_SAME)) {
+		zram_clear_flag(zram, index, ZRAM_SAME);
+		zram_clear_element(zram, index);
 		atomic64_dec(&zram->stats.same_pages);
 		return;
 	}
@@ -553,14 +529,14 @@ static void zram_free_page(struct zram *zram, size_t index)
 	if (!handle)
 		return;
 
-	zs_free(meta->mem_pool, handle);
+	zs_free(zram->mem_pool, handle);
 
-	atomic64_sub(zram_get_obj_size(meta, index),
+	atomic64_sub(zram_get_obj_size(zram, index),
 			&zram->stats.compr_data_size);
 	atomic64_dec(&zram->stats.pages_stored);
 
-	meta->table[index].handle = 0;
-	zram_set_obj_size(meta, index, 0);
+	zram->table[index].handle = 0;
+	zram_set_obj_size(zram, index, 0);
 }
 
 static int zram_decompress_page(struct zram *zram, struct page *page, u32 index)
@@ -569,16 +545,15 @@ static int zram_decompress_page(struct zram *zram, struct page *page, u32 index)
 	unsigned long handle;
 	unsigned int size;
 	void *src, *dst;
-	struct zram_meta *meta = zram->meta;
 
 	if (zram_special_page_read(zram, index, page, 0, PAGE_SIZE))
 		return 0;
 
 	zram_slot_lock(zram, index);
-	handle = meta->table[index].handle;
-	size = zram_get_obj_size(meta, index);
+	handle = zram->table[index].handle;
+	size = zram_get_obj_size(zram, index);
 
-	src = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
+	src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
 	if (size == PAGE_SIZE) {
 		dst = kmap_atomic(page);
 		copy_page(dst, src);
@@ -592,7 +567,7 @@ static int zram_decompress_page(struct zram *zram, struct page *page, u32 index)
 		kunmap_atomic(dst);
 		zcomp_stream_put(zram->comp);
 	}
-	zs_unmap_object(meta->mem_pool, handle);
+	zs_unmap_object(zram->mem_pool, handle);
 	zram_slot_unlock(zram, index);
 
 	/* Should NEVER happen. Return bio error if it does. */
@@ -647,7 +622,6 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
 	unsigned int comp_len;
 	void *src;
 	unsigned long handle = 0;
-	struct zram_meta *meta = zram->meta;
 
 compress_again:
 	src = kmap_atomic(page);
@@ -676,7 +650,7 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
 	 * from the slow path and handle has already been allocated.
 	 */
 	if (!handle)
-		handle = zs_malloc(meta->mem_pool, comp_len,
+		handle = zs_malloc(zram->mem_pool, comp_len,
 				__GFP_KSWAPD_RECLAIM |
 				__GFP_NOWARN |
 				__GFP_HIGHMEM |
@@ -684,7 +658,7 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
 	if (!handle) {
 		zcomp_stream_put(zram->comp);
 		atomic64_inc(&zram->stats.writestall);
-		handle = zs_malloc(meta->mem_pool, comp_len,
+		handle = zs_malloc(zram->mem_pool, comp_len,
 				GFP_NOIO | __GFP_HIGHMEM |
 				__GFP_MOVABLE);
 		*zstrm = zcomp_stream_get(zram->comp);
@@ -707,7 +681,6 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
 	void *src, *dst;
 	struct zcomp_strm *zstrm;
 	unsigned long alloced_pages;
-	struct zram_meta *meta = zram->meta;
 	struct page *page = bvec->bv_page;
 
 	if (zram_special_page_write(zram, index, page))
@@ -720,16 +693,16 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
 		return ret;
 	}
 
-	alloced_pages = zs_get_total_pages(meta->mem_pool);
+	alloced_pages = zs_get_total_pages(zram->mem_pool);
 	update_used_max(zram, alloced_pages);
 
 	if (zram->limit_pages && alloced_pages > zram->limit_pages) {
 		zcomp_stream_put(zram->comp);
-		zs_free(meta->mem_pool, handle);
+		zs_free(zram->mem_pool, handle);
 		return -ENOMEM;
 	}
 
-	dst = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
+	dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
 
 	if (comp_len == PAGE_SIZE) {
 		src = kmap_atomic(page);
@@ -740,7 +713,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
 	}
 
 	zcomp_stream_put(zram->comp);
-	zs_unmap_object(meta->mem_pool, handle);
+	zs_unmap_object(zram->mem_pool, handle);
 
 	/*
 	 * Free memory associated with this sector
@@ -748,8 +721,8 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
 	 */
 	zram_slot_lock(zram, index);
 	zram_free_page(zram, index);
-	meta->table[index].handle = handle;
-	zram_set_obj_size(meta, index, comp_len);
+	zram->table[index].handle = handle;
+	zram_set_obj_size(zram, index, comp_len);
 	zram_slot_unlock(zram, index);
 
 	/* Update stats */
@@ -934,10 +907,8 @@ 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;
 
 	zram_slot_lock(zram, index);
 	zram_free_page(zram, index);
@@ -985,7 +956,6 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
 
 static void zram_reset_device(struct zram *zram)
 {
-	struct zram_meta *meta;
 	struct zcomp *comp;
 	u64 disksize;
 
@@ -998,7 +968,6 @@ static void zram_reset_device(struct zram *zram)
 		return;
 	}
 
-	meta = zram->meta;
 	comp = zram->comp;
 	disksize = zram->disksize;
 
@@ -1011,7 +980,7 @@ static void zram_reset_device(struct zram *zram)
 
 	up_write(&zram->init_lock);
 	/* I/O operation under all of CPU are done so let's free */
-	zram_meta_free(meta, disksize);
+	zram_meta_free(zram, disksize);
 	zcomp_destroy(comp);
 }
 
@@ -1020,7 +989,6 @@ static ssize_t disksize_store(struct device *dev,
 {
 	u64 disksize;
 	struct zcomp *comp;
-	struct zram_meta *meta;
 	struct zram *zram = dev_to_zram(dev);
 	int err;
 
@@ -1029,8 +997,7 @@ static ssize_t disksize_store(struct device *dev,
 		return -EINVAL;
 
 	disksize = PAGE_ALIGN(disksize);
-	meta = zram_meta_alloc(zram->disk->disk_name, disksize);
-	if (!meta)
+	if (!zram_meta_alloc(zram, disksize))
 		return -ENOMEM;
 
 	comp = zcomp_create(zram->compressor);
@@ -1048,7 +1015,6 @@ static ssize_t disksize_store(struct device *dev,
 		goto out_destroy_comp;
 	}
 
-	zram->meta = meta;
 	zram->comp = comp;
 	zram->disksize = disksize;
 	set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
@@ -1061,7 +1027,7 @@ static ssize_t disksize_store(struct device *dev,
 	up_write(&zram->init_lock);
 	zcomp_destroy(comp);
 out_free_meta:
-	zram_meta_free(meta, disksize);
+	zram_meta_free(zram, disksize);
 	return err;
 }
 
@@ -1248,7 +1214,6 @@ static int zram_add(void)
 		goto out_free_disk;
 	}
 	strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));
-	zram->meta = NULL;
 
 	pr_info("Added device: %s\n", zram->disk->disk_name);
 	return device_id;
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index caeff51f1571..e34e44d02e3e 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -92,13 +92,9 @@ struct zram_stats {
 	atomic64_t writestall;		/* no. of write slow paths */
 };
 
-struct zram_meta {
+struct zram {
 	struct zram_table_entry *table;
 	struct zs_pool *mem_pool;
-};
-
-struct zram {
-	struct zram_meta *meta;
 	struct zcomp *comp;
 	struct gendisk *disk;
 	/* Prevent concurrent execution of device init */
-- 
2.7.4

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#1615664

FromSergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Date2017-04-04 04:40 +0200
Message-ID<tsmxY-76q-7@gated-at.bofh.it>
In reply to#1614881
On (04/03/17 14:17), Minchan Kim wrote:
[..]
> -static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
> +static bool zram_meta_alloc(struct zram *zram, u64 disksize)
>  {
>  	size_t num_pages;
> -	struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
> -
> -	if (!meta)
> -		return NULL;
>  
>  	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 out_error;
> -	}
> +	zram->table = vzalloc(num_pages * sizeof(*zram->table));
> +	if (!zram->table)
> +		return false;
>  
> -	meta->mem_pool = zs_create_pool(pool_name);
> -	if (!meta->mem_pool) {
> -		pr_err("Error creating memory pool\n");
> -		goto out_error;
> +	zram->mem_pool = zs_create_pool(zram->disk->disk_name);
> +	if (!zram->mem_pool) {
> +		vfree(zram->table);
> +		return false;
>  	}
>  
> -	return meta;
> -
> -out_error:
> -	vfree(meta->table);
> -	kfree(meta);
> -	return NULL;
> +	return true;
>  }

[..]

> @@ -1020,7 +989,6 @@ static ssize_t disksize_store(struct device *dev,
>  {
>  	u64 disksize;
>  	struct zcomp *comp;
> -	struct zram_meta *meta;
>  	struct zram *zram = dev_to_zram(dev);
>  	int err;
>  
> @@ -1029,8 +997,7 @@ static ssize_t disksize_store(struct device *dev,
>  		return -EINVAL;
>  
>  	disksize = PAGE_ALIGN(disksize);
> -	meta = zram_meta_alloc(zram->disk->disk_name, disksize);
> -	if (!meta)
> +	if (!zram_meta_alloc(zram, disksize))
>  		return -ENOMEM;
>  
>  	comp = zcomp_create(zram->compressor);
> @@ -1048,7 +1015,6 @@ static ssize_t disksize_store(struct device *dev,
>  		goto out_destroy_comp;
>  	}
>  
> -	zram->meta = meta;
>  	zram->comp = comp;
>  	zram->disksize = disksize;
>  	set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
> @@ -1061,7 +1027,7 @@ static ssize_t disksize_store(struct device *dev,
>  	up_write(&zram->init_lock);
>  	zcomp_destroy(comp);
>  out_free_meta:
> -	zram_meta_free(meta, disksize);
> +	zram_meta_free(zram, disksize);
>  	return err;
>  }

OK, I don't think it's the same.

we used to have

	struct zram_meta *zram_meta_alloc()
	{
		meta->table = vzalloc()
		meta->mem_pool = zs_create_pool();
		return meta;
	}


	disksize_store()
	{
		meta = zram_meta_alloc();
		if (init_done(zram)) {
			pr_info("Cannot change disksize for initialized device\n");
			goto out_destroy_comp;
		}

		zram->meta = meta;
		^^^^^^^^^^^^^^^^^^
	}

now we have

	struct zram_meta *zram_meta_alloc()
	{
		zram->table = vzalloc()
		zram->mem_pool = zs_create_pool();
		return true;
	}


	disksize_store()
	{
		zram_meta_alloc();
		^^^^^^^^^^^^^^^^^
		if (init_done(zram)) {
			pr_info("Cannot change disksize for initialized device\n");
			goto out_destroy_comp;
		}
	}


by the time we call init_done(zram) on already init device zram->table
and zram->mem_pool are overwritten and lost. right?


[..]
> -struct zram_meta {
> +struct zram {
>  	struct zram_table_entry *table;
>  	struct zs_pool *mem_pool;
> -};
> -
> -struct zram {
> -	struct zram_meta *meta;
>  	struct zcomp *comp;
>  	struct gendisk *disk;
>  	/* Prevent concurrent execution of device init */


we still have several zram_meta_FOO() left overs in zram_drv.c

	-ss

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#1615703

FromMinchan Kim <minchan@kernel.org>
Date2017-04-04 07:00 +0200
Message-ID<tsoJr-8um-3@gated-at.bofh.it>
In reply to#1615664
On Tue, Apr 04, 2017 at 11:31:15AM +0900, Sergey Senozhatsky wrote:
> On (04/03/17 14:17), Minchan Kim wrote:
> [..]
> > -static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
> > +static bool zram_meta_alloc(struct zram *zram, u64 disksize)
> >  {
> >  	size_t num_pages;
> > -	struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
> > -
> > -	if (!meta)
> > -		return NULL;
> >  
> >  	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 out_error;
> > -	}
> > +	zram->table = vzalloc(num_pages * sizeof(*zram->table));
> > +	if (!zram->table)
> > +		return false;
> >  
> > -	meta->mem_pool = zs_create_pool(pool_name);
> > -	if (!meta->mem_pool) {
> > -		pr_err("Error creating memory pool\n");
> > -		goto out_error;
> > +	zram->mem_pool = zs_create_pool(zram->disk->disk_name);
> > +	if (!zram->mem_pool) {
> > +		vfree(zram->table);
> > +		return false;
> >  	}
> >  
> > -	return meta;
> > -
> > -out_error:
> > -	vfree(meta->table);
> > -	kfree(meta);
> > -	return NULL;
> > +	return true;
> >  }
> 
> [..]
> 
> > @@ -1020,7 +989,6 @@ static ssize_t disksize_store(struct device *dev,
> >  {
> >  	u64 disksize;
> >  	struct zcomp *comp;
> > -	struct zram_meta *meta;
> >  	struct zram *zram = dev_to_zram(dev);
> >  	int err;
> >  
> > @@ -1029,8 +997,7 @@ static ssize_t disksize_store(struct device *dev,
> >  		return -EINVAL;
> >  
> >  	disksize = PAGE_ALIGN(disksize);
> > -	meta = zram_meta_alloc(zram->disk->disk_name, disksize);
> > -	if (!meta)
> > +	if (!zram_meta_alloc(zram, disksize))
> >  		return -ENOMEM;
> >  
> >  	comp = zcomp_create(zram->compressor);
> > @@ -1048,7 +1015,6 @@ static ssize_t disksize_store(struct device *dev,
> >  		goto out_destroy_comp;
> >  	}
> >  
> > -	zram->meta = meta;
> >  	zram->comp = comp;
> >  	zram->disksize = disksize;
> >  	set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
> > @@ -1061,7 +1027,7 @@ static ssize_t disksize_store(struct device *dev,
> >  	up_write(&zram->init_lock);
> >  	zcomp_destroy(comp);
> >  out_free_meta:
> > -	zram_meta_free(meta, disksize);
> > +	zram_meta_free(zram, disksize);
> >  	return err;
> >  }
> 
> OK, I don't think it's the same.
> 
> we used to have
> 
> 	struct zram_meta *zram_meta_alloc()
> 	{
> 		meta->table = vzalloc()
> 		meta->mem_pool = zs_create_pool();
> 		return meta;
> 	}
> 
> 
> 	disksize_store()
> 	{
> 		meta = zram_meta_alloc();
> 		if (init_done(zram)) {
> 			pr_info("Cannot change disksize for initialized device\n");
> 			goto out_destroy_comp;
> 		}
> 
> 		zram->meta = meta;
> 		^^^^^^^^^^^^^^^^^^
> 	}
> 
> now we have
> 
> 	struct zram_meta *zram_meta_alloc()
> 	{
> 		zram->table = vzalloc()
> 		zram->mem_pool = zs_create_pool();
> 		return true;
> 	}
> 
> 
> 	disksize_store()
> 	{
> 		zram_meta_alloc();
> 		^^^^^^^^^^^^^^^^^
> 		if (init_done(zram)) {
> 			pr_info("Cannot change disksize for initialized device\n");
> 			goto out_destroy_comp;
> 		}
> 	}
> 
> 
> by the time we call init_done(zram) on already init device zram->table
> and zram->mem_pool are overwritten and lost. right?

Right you are.
I will fix it!

> 
> 
> [..]
> > -struct zram_meta {
> > +struct zram {
> >  	struct zram_table_entry *table;
> >  	struct zs_pool *mem_pool;
> > -};
> > -
> > -struct zram {
> > -	struct zram_meta *meta;
> >  	struct zcomp *comp;
> >  	struct gendisk *disk;
> >  	/* Prevent concurrent execution of device init */
> 
> 
> we still have several zram_meta_FOO() left overs in zram_drv.c
> 
> 	-ss

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#1615715

FromMinchan Kim <minchan@kernel.org>
Date2017-04-04 07:50 +0200
Message-ID<tspvP-BB-5@gated-at.bofh.it>
In reply to#1615664
On Tue, Apr 04, 2017 at 11:31:15AM +0900, Sergey Senozhatsky wrote:
< snip >

> 
> [..]
> > -struct zram_meta {
> > +struct zram {
> >  	struct zram_table_entry *table;
> >  	struct zs_pool *mem_pool;
> > -};
> > -
> > -struct zram {
> > -	struct zram_meta *meta;
> >  	struct zcomp *comp;
> >  	struct gendisk *disk;
> >  	/* Prevent concurrent execution of device init */
> 
> 
> we still have several zram_meta_FOO() left overs in zram_drv.c

I intentionally used that term because I don't think better name
to wrap logis which allocates table and mempool.
Feel free to suggest if you have better.

Thanks.

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#1615716

FromSergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Date2017-04-04 08:00 +0200
Message-ID<tspFv-FV-3@gated-at.bofh.it>
In reply to#1615715
On (04/04/17 14:40), Minchan Kim wrote:
> > [..]
> > > -struct zram_meta {
> > > +struct zram {
> > >  	struct zram_table_entry *table;
> > >  	struct zs_pool *mem_pool;
> > > -};
> > > -
> > > -struct zram {
> > > -	struct zram_meta *meta;
> > >  	struct zcomp *comp;
> > >  	struct gendisk *disk;
> > >  	/* Prevent concurrent execution of device init */
> > 
> > 
> > we still have several zram_meta_FOO() left overs in zram_drv.c
> 
> I intentionally used that term because I don't think better name
> to wrap logis which allocates table and mempool.

ah, it was intentional. um, OK, let's keep zram_meta_foo().

	-ss

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