[PATCH v5 1/4] zram: Fix deadlock bug in partial write

[Minchan Kim <minchan@kernel.org>]

Now zram allocates new page with GFP_KERNEL in zram I/O path
if IO is partial. Unfortunately, It may cuase deadlock with
reclaim path so this patch solves the problem.

Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 drivers/staging/zram/zram_drv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 61fb8f1..b285b3a 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -220,7 +220,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 	user_mem = kmap_atomic(page);
 	if (is_partial_io(bvec))
 		/* Use  a temporary buffer to decompress the page */
-		uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		uncmem = kmalloc(PAGE_SIZE, GFP_ATOMIC);
 	else
 		uncmem = user_mem;
 
@@ -268,7 +268,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
 		 * This is a partial IO. We need to read the full page
 		 * before to write the changes.
 		 */
-		uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
 		if (!uncmem) {
 			pr_info("Error allocating temp memory!\n");
 			ret = -ENOMEM;
-- 
1.7.9.5

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