From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nitin Gupta <ngupta@vflare.org>,
linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: Re: [PATCHv3 9/9] zram: add dynamic device add/remove functionality
Date: Mon, 4 May 2015 20:34:40 +0900 [thread overview]
Message-ID: <20150504113406.GA505@swordfish> (raw)
In-Reply-To: <20150504022008.GA14452@blaptop>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 3df4394..7fb72dc 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -1074,13 +1074,6 @@ static ssize_t reset_store(struct device *dev,
> if (!bdev)
> return -ENOMEM;
>
> - mutex_lock(&bdev->bd_mutex);
> - /* Do not reset an active device! */
> - if (bdev->bd_openers) {
> - ret = -EBUSY;
> - goto out;
> - }
> -
> ret = kstrtou16(buf, 10, &do_reset);
> if (ret)
> goto out;
> @@ -1090,23 +1083,52 @@ static ssize_t reset_store(struct device *dev,
> goto out;
> }
>
> + mutex_lock(&bdev->bd_mutex);
> + /* Do not reset an active device or claimed device */
> + if (bdev->bd_openers || zram->claim) {
> + ret = -EBUSY;
> + mutex_unlock(&bdev->bd_mutex);
> + goto out;
> + }
> +
> + /* From now on, anyone can't open /dev/zram[0-9] */
> + zram->claim = true;
> + mutex_unlock(&bdev->bd_mutex);
> +
> /* Make sure all pending I/O is finished */
> fsync_bdev(bdev);
> zram_reset_device(zram);
>
> - mutex_unlock(&bdev->bd_mutex);
> revalidate_disk(zram->disk);
> bdput(bdev);
>
> - return len;
> + mutex_lock(&bdev->bd_mutex);
> + zram->claim = false;
> + mutex_unlock(&bdev->bd_mutex);
>
> + return len;
> out:
> - mutex_unlock(&bdev->bd_mutex);
> bdput(bdev);
> return ret;
just backported reset_store() simplification from my another patch.
make validation outisde of ->bd_mutex and before we inc ndev ref
counter in bdget_disk(). this also makes it possible to get rid of
goto label.
the rest looks ok to me. will fold into your patch and submit.
---
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 7fb72dc..f50bd66 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1068,27 +1068,24 @@ static ssize_t reset_store(struct device *dev,
struct zram *zram;
struct block_device *bdev;
+ ret = kstrtou16(buf, 10, &do_reset);
+ if (ret)
+ return ret;
+
+ if (!do_reset)
+ return -EINVAL;
+
zram = dev_to_zram(dev);
bdev = bdget_disk(zram->disk, 0);
-
if (!bdev)
return -ENOMEM;
- ret = kstrtou16(buf, 10, &do_reset);
- if (ret)
- goto out;
-
- if (!do_reset) {
- ret = -EINVAL;
- goto out;
- }
-
mutex_lock(&bdev->bd_mutex);
/* Do not reset an active device or claimed device */
if (bdev->bd_openers || zram->claim) {
- ret = -EBUSY;
mutex_unlock(&bdev->bd_mutex);
- goto out;
+ bdput(bdev);
+ return -EBUSY;
}
/* From now on, anyone can't open /dev/zram[0-9] */
@@ -1107,9 +1104,6 @@ static ssize_t reset_store(struct device *dev,
mutex_unlock(&bdev->bd_mutex);
return len;
-out:
- bdput(bdev);
- return ret;
}
static int zram_open(struct block_device *bdev, fmode_t mode)
next prev parent reply other threads:[~2015-05-04 11:35 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-27 13:21 [PATCHv3 0/9] introduce on-demand device creation Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 1/9] zram: add `compact` sysfs entry to documentation Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 2/9] zram: cosmetic ZRAM_ATTR_RO code formatting tweak Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 3/9] zram: use idr instead of `zram_devices' array Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 4/9] zram: reorganize code layout Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 5/9] zram: remove max_num_devices limitation Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 6/9] zram: report every added and removed device Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 7/9] zram: trivial: correct flag operations comment Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 8/9] zram: return zram device_id from zram_add() Sergey Senozhatsky
2015-04-27 13:21 ` [PATCHv3 9/9] zram: add dynamic device add/remove functionality Sergey Senozhatsky
2015-04-29 0:16 ` Sergey Senozhatsky
2015-04-29 6:48 ` Minchan Kim
2015-04-29 7:02 ` Sergey Senozhatsky
2015-04-29 7:23 ` Sergey Senozhatsky
2015-04-30 5:47 ` Minchan Kim
2015-04-30 6:34 ` Sergey Senozhatsky
2015-04-30 6:44 ` Minchan Kim
2015-04-30 6:51 ` Sergey Senozhatsky
2015-05-04 2:20 ` Minchan Kim
2015-05-04 2:28 ` Minchan Kim
2015-05-04 6:32 ` Sergey Senozhatsky
2015-05-04 6:29 ` Sergey Senozhatsky
2015-05-04 11:34 ` Sergey Senozhatsky [this message]
2015-04-30 6:44 ` Sergey Senozhatsky
2015-04-27 13:41 ` [PATCHv3 0/9] introduce on-demand device creation Sergey Senozhatsky
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