mm/zpool: add name argument to create zpool

Currently the underlay of zpool: zsmalloc/zbud, do not know who creates
them.  There is not a method to let zsmalloc/zbud find which caller they
belong to.

Now we want to add statistics collection in zsmalloc.  We need to name the
debugfs dir for each pool created.  The way suggested by Minchan Kim is to
use a name passed by caller(such as zram) to create the zsmalloc pool.

    /sys/kernel/debug/zsmalloc/zram0

This patch adds an argument `name' to zs_create_pool() and other related
functions.

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index eca4b67274c1..8e233edd7a09 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -327,9 +327,10 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize)
         kfree(meta);
 }
 
-static struct zram_meta *zram_meta_alloc(u64 disksize)
+static struct zram_meta *zram_meta_alloc(int device_id, u64 disksize)
 {
         size_t num_pages;
+        char pool_name[8];
         struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
 
         if (!meta)
@@ -342,7 +343,8 @@ static struct zram_meta *zram_meta_alloc(u64 disksize)
                 goto out_error;
         }
 
-        meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM);
+        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");
                 goto out_error;
@@ -783,7 +785,7 @@ static ssize_t disksize_store(struct device *dev,
                 return -EINVAL;
 
         disksize = PAGE_ALIGN(disksize);
-        meta = zram_meta_alloc(disksize);
+        meta = zram_meta_alloc(zram->disk->first_minor, disksize);
         if (!meta)
                 return -ENOMEM;