diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index 54ad29d6cf4628949e9f1890a89f3634d60a1dd3..c5fdc55361860b23b469d89c1254cba5bc04d44c 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -359,8 +359,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, zram_test_flag(zram, index, ZRAM_ZERO)) zram_free_page(zram, index); - mutex_lock(&zram->lock); - user_mem = kmap_atomic(page, KM_USER0); if (is_partial_io(bvec)) @@ -371,7 +369,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, if (page_zero_filled(uncmem)) { kunmap_atomic(user_mem, KM_USER0); - mutex_unlock(&zram->lock); if (is_partial_io(bvec)) kfree(uncmem); zram_stat_inc(&zram->stats.pages_zero); @@ -388,7 +385,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, kfree(uncmem); if (unlikely(ret != LZO_E_OK)) { - mutex_unlock(&zram->lock); pr_err("Compression failed! err=%d\n", ret); goto out; } @@ -402,7 +398,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, clen = PAGE_SIZE; page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM); if (unlikely(!page_store)) { - mutex_unlock(&zram->lock); pr_info("Error allocating memory for " "incompressible page: %u\n", index); ret = -ENOMEM; @@ -420,7 +415,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, if (xv_malloc(zram->mem_pool, clen + sizeof(*zheader), &zram->table[index].page, &store_offset, GFP_NOIO | __GFP_HIGHMEM)) { - mutex_unlock(&zram->lock); pr_info("Error allocating memory for compressed " "page: %u, size=%zu\n", index, clen); ret = -ENOMEM; @@ -454,8 +448,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, if (clen <= PAGE_SIZE / 2) zram_stat_inc(&zram->stats.good_compress); - mutex_unlock(&zram->lock); - return 0; out: @@ -467,10 +459,19 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio, int rw) { - if (rw == READ) - return zram_bvec_read(zram, bvec, index, offset, bio); + int ret; - return zram_bvec_write(zram, bvec, index, offset); + if (rw == READ) { + down_read(&zram->lock); + ret = zram_bvec_read(zram, bvec, index, offset, bio); + up_read(&zram->lock); + } else { + down_write(&zram->lock); + ret = zram_bvec_write(zram, bvec, index, offset); + up_write(&zram->lock); + } + + return ret; } static void update_position(u32 *index, int *offset, struct bio_vec *bvec) @@ -701,7 +702,7 @@ static int create_device(struct zram *zram, int device_id) { int ret = 0; - mutex_init(&zram->lock); + init_rwsem(&zram->lock); mutex_init(&zram->init_lock); spin_lock_init(&zram->stat64_lock); diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index 8acf9eba79c81bd30018c6900343918a014bfeb3..abe5221c100dc467df1405a7016ac5dccf906a14 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -107,8 +107,8 @@ struct zram { void *compress_buffer; struct table *table; spinlock_t stat64_lock; /* protect 64-bit stats */ - struct mutex lock; /* protect compression buffers against - * concurrent writes */ + struct rw_semaphore lock; /* protect compression buffers and table + * against concurrent read and writes */ struct request_queue *queue; struct gendisk *disk; int init_done;