From: Vivek Goyal <vgoyal@redhat.com>
To: Phillip Susi <psusi@cfl.rr.com>
Cc: joe@perches.com, kzak@redhat.com, linux-kernel@vger.kernel.org,
jaxboe@fusionio.com
Subject: Re: [PATCH 1/2] Add partition resize function to BLKPG ioctl
Date: Mon, 19 Dec 2011 15:25:27 -0500 [thread overview]
Message-ID: <20111219202527.GF7175@redhat.com> (raw)
In-Reply-To: <1323735382-5972-1-git-send-email-psusi@cfl.rr.com>
On Mon, Dec 12, 2011 at 07:16:21PM -0500, Phillip Susi wrote:
[..]
> + case BLKPG_RESIZE_PARTITION:
> + start = p.start >> 9;
> + length = p.length >> 9;
> + /* check for fit in a hd_struct */
> + if (sizeof(sector_t) == sizeof(long) &&
> + sizeof(long long) > sizeof(long)) {
> + long pstart = start, plength = length;
> + if (pstart != start || plength != length
> + || pstart < 0 || plength < 0)
> + return -EINVAL;
> + }
> +
> + mutex_lock(&bdev->bd_mutex);
> +
> + /* overlap? */
> + disk_part_iter_init(&piter, disk,
> + DISK_PITER_INCL_EMPTY);
> + while ((part = disk_part_iter_next(&piter))) {
> + if (part->partno != partno && !(start + length <= part->start_sect ||
> + start >= part->start_sect + part->nr_sects)) {
> + disk_part_iter_exit(&piter);
> + mutex_unlock(&bdev->bd_mutex);
> + return -EBUSY;
> + }
> + }
> + disk_part_iter_exit(&piter);
> + part = disk_get_part(disk, partno);
> + if (!part)
> + {
> + mutex_unlock(&bdev->bd_mutex);
> + return -ENXIO;
> + }
> + if (start != part->start_sect)
> + {
> + mutex_unlock(&bdev->bd_mutex);
> + disk_put_part(part);
> + return -EINVAL;
> + }
> + part->nr_sects = length;
> + bdevp = bdget(part_devt(part));
> + mutex_lock(&bdevp->bd_mutex);
Are there any restrictions on order of partition bdev and disk bdev
locking.
I see that DEL_PARTITION ioctl first takes partition mutex and then
disk mutex using mutex_lock_nested().
In your implementation you take disk mutex first and the partition
bdev mutex.
- Is that a problem from deadlock point of view? Two threads calling
ioctl on same fd.
- Is it an issue from lock validator point of view. I am not familiar
with mutex_lock_nested(). So thought of asking.
Thanks
Vivek
next prev parent reply other threads:[~2011-12-19 20:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1322709471.git.psusi@cfl.rr.com>
2011-12-01 3:23 ` [PATCH 1/2] Add partition resize function to BLKPG ioctl Phillip Susi
2011-12-08 12:30 ` Karel Zak
2011-12-08 14:22 ` Phillip Susi
2011-12-08 15:16 ` Karel Zak
2011-12-08 15:25 ` Phillip Susi
2011-12-08 15:58 ` Vivek Goyal
2011-12-08 16:06 ` Phillip Susi
2011-12-08 16:28 ` Vivek Goyal
2011-12-08 16:55 ` Phillip Susi
2011-12-09 2:53 ` Phillip Susi
2011-12-12 14:53 ` Vivek Goyal
2011-12-12 17:43 ` Phillip Susi
2011-12-12 17:49 ` Joe Perches
2011-12-12 18:04 ` Vivek Goyal
2011-12-13 0:15 ` Phillip Susi
2011-12-13 0:16 ` Phillip Susi
2011-12-13 0:16 ` [PATCH 2/2] Add BLKPG_GET_PARTITION operation Phillip Susi
2011-12-19 20:25 ` Vivek Goyal [this message]
2011-12-21 1:53 ` [PATCH 1/2] Add partition resize function to BLKPG ioctl Phillip Susi
2011-12-21 1:54 ` Phillip Susi
2011-12-21 1:54 ` [PATCH 2/2] Add BLKPG_GET_PARTITION operation Phillip Susi
2011-12-21 20:46 ` [PATCH 1/2] Add partition resize function to BLKPG ioctl Vivek Goyal
2011-12-24 21:36 ` Phillip Susi
2011-12-24 22:21 ` Phillip Susi
2011-12-24 22:21 ` [PATCH 2/2] Add BLKPG_GET_PARTITION operation Phillip Susi
2011-12-01 3:23 ` Phillip Susi
2011-12-08 12:35 ` Karel Zak
2011-12-08 14:25 ` Phillip Susi
2011-12-29 17:06 [PATCH 1/2] Add partition resize function to BLKPG ioctl Maxim Patlasov
2011-12-30 0:09 ` Phillip Susi
2012-01-01 21:49 ` Phillip Susi
2012-01-26 19:01 ` Vivek Goyal
2012-01-26 20:35 ` Phillip Susi
2012-01-26 21:04 ` Vivek Goyal
2012-01-26 21:48 ` Phillip Susi
2012-01-30 15:49 ` Vivek Goyal
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