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| author | Sergey Senozhatsky <sergey.senozhatsky@gmail.com> | 2015-08-14 15:35:19 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-14 15:56:32 -0700 |
| commit | 4ce321f574a97f3453bca5a4117610b43dabd3ee (patch) | |
| tree | 0d615f7abf1f080f541a031015f24e7acfbee777 | |
| parent | f9126ab9241f66562debf69c2c9d8fee32ddcc53 (diff) | |
| download | linux-4ce321f574a97f3453bca5a4117610b43dabd3ee.tar.bz2 | |
zram: fix pool name truncation
zram_meta_alloc() constructs a pool name for zs_create_pool() call as
snprintf(pool_name, sizeof(pool_name), "zram%d", device_id);
However, it defines pool name buffer to be only 8 bytes long (minus
trailing zero), which means that we can have only 1000 pool names: zram0
-- zram999.
With CONFIG_ZSMALLOC_STAT enabled an attempt to create a device zram1000
can fail if device zram100 already exists, because snprintf() will
truncate new pool name to zram100 and pass it debugfs_create_dir(),
causing:
debugfs dir <zram100> creation failed
zram: Error creating memory pool
... and so on.
Fix it by passing zram->disk->disk_name to zram_meta_alloc() instead of
divice_id. We construct zram%d name earlier and keep it as a ->disk_name,
no need to snprintf() it again.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fb655e8d1e3b..763301c7828c 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -496,10 +496,9 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize) kfree(meta); } -static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) +static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize) { size_t num_pages; - char pool_name[8]; struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL); if (!meta) @@ -512,7 +511,6 @@ static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize) goto out_error; } - snprintf(pool_name, sizeof(pool_name), "zram%d", device_id); meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM); if (!meta->mem_pool) { pr_err("Error creating memory pool\n"); @@ -1031,7 +1029,7 @@ static ssize_t disksize_store(struct device *dev, return -EINVAL; disksize = PAGE_ALIGN(disksize); - meta = zram_meta_alloc(zram->disk->first_minor, disksize); + meta = zram_meta_alloc(zram->disk->disk_name, disksize); if (!meta) return -ENOMEM; |