zram: clarify writeback_store() comment

Re-phrase writeback BIO error comment.

Link: https://lkml.kernel.org/r/20221109115047.2921851-7-senozhatsky@chromium.org
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Alexey Romanov <avromanov@sberdevices.ru>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index ddbfa70ef9a331b9e05e2ce4955cf3c4bbc22ee3..0ca0bf330d8f9de8723d4b0a9b445ce37378022f 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -769,8 +769,12 @@ static ssize_t writeback_store(struct device *dev,
                        zram_clear_flag(zram, index, ZRAM_IDLE);
                        zram_slot_unlock(zram, index);
                        /*
-                        * Return last IO error unless every IO were
-                        * not suceeded.
+                        * BIO errors are not fatal, we continue and simply
+                        * attempt to writeback the remaining objects (pages).
+                        * At the same time we need to signal user-space that
+                        * some writes (at least one, but also could be all of
+                        * them) were not successful and we do so by returning
+                        * the most recent BIO error.
                         */
                        ret = err;
                        continue;