diff options
authorMinchan Kim <minchan@kernel.org>2021-03-12 21:08:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-03-13 11:27:31 -0800
commit57e0076e6575a7b7cef620a0bd2ee2549ef77818 (patch)
parente1baddf8475b06cc56f4bafecf9a32a124343d9f (diff)
zram: fix return value on writeback_store
writeback_store's return value is overwritten by submit_bio_wait's return value. Thus, writeback_store will return zero since there was no IO error. In the end, write syscall from userspace will see the zero as return value, which could make the process stall to keep trying the write until it will succeed. Link: https://lkml.kernel.org/r/20210312173949.2197662-1-minchan@kernel.org Fixes: 3b82a051c101("drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store") Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: John Dias <joaodias@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index a711a2e2a794..63bbefdffc81 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -627,7 +627,7 @@ static ssize_t writeback_store(struct device *dev,
struct bio_vec bio_vec;
struct page *page;
ssize_t ret = len;
- int mode;
+ int mode, err;
unsigned long blk_idx = 0;
if (sysfs_streq(buf, "idle"))
@@ -728,12 +728,17 @@ static ssize_t writeback_store(struct device *dev,
* XXX: A single page IO would be inefficient for write
* but it would be not bad as starter.
- ret = submit_bio_wait(&bio);
- if (ret) {
+ err = submit_bio_wait(&bio);
+ if (err) {
zram_slot_lock(zram, index);
zram_clear_flag(zram, index, ZRAM_UNDER_WB);
zram_clear_flag(zram, index, ZRAM_IDLE);
zram_slot_unlock(zram, index);
+ /*
+ * Return last IO error unless every IO were
+ * not suceeded.
+ */
+ ret = err;

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