zram: remove zram_meta structure

It's redundant now.  Instead, remove it and use zram structure directly.

Link: http://lkml.kernel.org/r/1492052365-16169-5-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 78 insertions, 117 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index aac48ff69618..c674d23539b1 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
@@ -250,9 +250,8 @@ 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);
 
@@ -325,7 +324,6 @@ 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)) {
@@ -333,8 +331,7 @@ 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;
@@ -371,8 +368,8 @@ 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);
@@ -415,32 +412,26 @@ 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_same_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;
         }
@@ -456,14 +447,12 @@ static bool zram_same_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);
@@ -474,56 +463,44 @@ static bool zram_same_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;
 }
 
 /*
@@ -533,16 +510,15 @@ out_error:
  */
 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;
         }
@@ -550,14 +526,14 @@ 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)
@@ -566,16 +542,15 @@ 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_same_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);
                 memcpy(dst, src, PAGE_SIZE);
@@ -589,7 +564,7 @@ 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. */
@@ -641,7 +616,6 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
         void *src;
         unsigned long alloced_pages;
         unsigned long handle = 0;
-        struct zram_meta *meta = zram->meta;
 
 compress_again:
         src = kmap_atomic(page);
@@ -651,7 +625,7 @@ compress_again:
         if (unlikely(ret)) {
                 pr_err("Compression failed! err=%d\n", ret);
                 if (handle)
-                        zs_free(meta->mem_pool, handle);
+                        zs_free(zram->mem_pool, handle);
                 return ret;
         }
 
@@ -672,7 +646,7 @@ compress_again:
          * 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 |
@@ -680,7 +654,7 @@ compress_again:
         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);
@@ -689,11 +663,11 @@ compress_again:
                 return -ENOMEM;
         }
 
-        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) {
-                zs_free(meta->mem_pool, handle);
+                zs_free(zram->mem_pool, handle);
                 return -ENOMEM;
         }
 
@@ -709,7 +683,6 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
         unsigned int comp_len;
         void *src, *dst;
         struct zcomp_strm *zstrm;
-        struct zram_meta *meta = zram->meta;
         struct page *page = bvec->bv_page;
 
         if (zram_same_page_write(zram, index, page))
@@ -722,8 +695,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
                 return ret;
         }
 
-
-        dst = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
+        dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
 
         src = zstrm->buffer;
         if (comp_len == PAGE_SIZE)
@@ -733,7 +705,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
                 kunmap_atomic(src);
 
         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
@@ -741,8 +713,8 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
          */
         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 */
@@ -932,10 +904,8 @@ 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);
@@ -983,7 +953,6 @@ out:
 
 static void zram_reset_device(struct zram *zram)
 {
-        struct zram_meta *meta;
         struct zcomp *comp;
         u64 disksize;
 
@@ -996,7 +965,6 @@ static void zram_reset_device(struct zram *zram)
                 return;
         }
 
-        meta = zram->meta;
         comp = zram->comp;
         disksize = zram->disksize;
 
@@ -1009,7 +977,7 @@ 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);
 }
 
@@ -1018,7 +986,6 @@ 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;
 
@@ -1026,10 +993,18 @@ static ssize_t disksize_store(struct device *dev,
         if (!disksize)
                 return -EINVAL;
 
+        down_write(&zram->init_lock);
+        if (init_done(zram)) {
+                pr_info("Cannot change disksize for initialized device\n");
+                err = -EBUSY;
+                goto out_unlock;
+        }
+
         disksize = PAGE_ALIGN(disksize);
-        meta = zram_meta_alloc(zram->disk->disk_name, disksize);
-        if (!meta)
-                return -ENOMEM;
+        if (!zram_meta_alloc(zram, disksize)) {
+                err = -ENOMEM;
+                goto out_unlock;
+        }
 
         comp = zcomp_create(zram->compressor);
         if (IS_ERR(comp)) {
@@ -1039,14 +1014,6 @@ static ssize_t disksize_store(struct device *dev,
                 goto out_free_meta;
         }
 
-        down_write(&zram->init_lock);
-        if (init_done(zram)) {
-                pr_info("Cannot change disksize for initialized device\n");
-                err = -EBUSY;
-                goto out_destroy_comp;
-        }
-
-        zram->meta = meta;
         zram->comp = comp;
         zram->disksize = disksize;
         set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
@@ -1055,11 +1022,10 @@ static ssize_t disksize_store(struct device *dev,
 
         return len;
 
-out_destroy_comp:
-        up_write(&zram->init_lock);
-        zcomp_destroy(comp);
 out_free_meta:
-        zram_meta_free(meta, disksize);
+        zram_meta_free(zram, disksize);
+out_unlock:
+        up_write(&zram->init_lock);
         return err;
 }
 
@@ -1245,7 +1211,6 @@ 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 */