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From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Minchan Kim <minchan@kernel.org>
Cc:     Nitin Gupta <ngupta@vflare.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCHv4 8/9] zram: Clarify writeback_store() comment
Date:   Tue, 18 Oct 2022 13:55:32 +0900
Message-Id: <20221018045533.2396670-9-senozhatsky@chromium.org>
In-Reply-To: <20221018045533.2396670-1-senozhatsky@chromium.org>
References: <20221018045533.2396670-1-senozhatsky@chromium.org>
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Re-phrase writeback BIO error comment.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/block/zram/zram_drv.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 5d760467e0bc..6b56f6f2ce82 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -758,8 +758,12 @@ 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;
-- 
2.38.0.413.g74048e4d9e-goog