@@ -627,7 +627,7 @@ static ssize_t writeback_store(struct de
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 de
* 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;
continue;
}
The patch titled Subject: zram: fix return value on writeback_store has been added to the -mm tree. Its filename is zram-fix-return-value-on-writeback_store.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/zram-fix-return-value-on-writeback_store.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/zram-fix-return-value-on-writeback_store.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Minchan Kim <minchan@kernel.org> Subject: 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> --- drivers/block/zram/zram_drv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)