From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>, Song Liu <song@kernel.org>
Cc: "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"Roger Pau Monné" <roger.pau@citrix.com>,
"Minchan Kim" <minchan@kernel.org>,
"Nitin Gupta" <ngupta@vflare.org>,
"Stefan Haberland" <sth@linux.ibm.com>,
"Jan Hoeppner" <hoeppner@linux.ibm.com>,
linux-block@vger.kernel.org, linux-raid@vger.kernel.org,
linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: [PATCH 05/15] md: refactor mddev_find_or_alloc
Date: Tue, 30 Mar 2021 18:17:17 +0200 [thread overview]
Message-ID: <20210330161727.2297292-6-hch@lst.de> (raw)
In-Reply-To: <20210330161727.2297292-1-hch@lst.de>
Allocate the new mddev first speculatively, which greatly simplifies
the code flow.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/md.c | 60 ++++++++++++++++++++-----------------------------
1 file changed, 24 insertions(+), 36 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8e60bcc9c1d10c..ea9c92c113619b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -784,57 +784,45 @@ static struct mddev *mddev_find(dev_t unit)
static struct mddev *mddev_find_or_alloc(dev_t unit)
{
- struct mddev *mddev, *new = NULL;
+ struct mddev *mddev = NULL, *new;
if (unit && MAJOR(unit) != MD_MAJOR)
- unit &= ~((1<<MdpMinorShift)-1);
+ unit &= ~((1 << MdpMinorShift) - 1);
- retry:
- spin_lock(&all_mddevs_lock);
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return NULL;
+ mddev_init(new);
+ spin_lock(&all_mddevs_lock);
if (unit) {
mddev = mddev_find_locked(unit);
if (mddev) {
mddev_get(mddev);
- spin_unlock(&all_mddevs_lock);
- kfree(new);
- return mddev;
+ goto out_free_new;
}
- if (new) {
- list_add(&new->all_mddevs, &all_mddevs);
- spin_unlock(&all_mddevs_lock);
- new->hold_active = UNTIL_IOCTL;
- return new;
- }
- } else if (new) {
+ new->unit = unit;
+ if (MAJOR(unit) == MD_MAJOR)
+ new->md_minor = MINOR(unit);
+ else
+ new->md_minor = MINOR(unit) >> MdpMinorShift;
+ new->hold_active = UNTIL_IOCTL;
+ } else {
new->unit = mddev_alloc_unit();
- if (!new->unit) {
- spin_unlock(&all_mddevs_lock);
- kfree(new);
- return NULL;
- }
+ if (!new->unit)
+ goto out_free_new;
new->md_minor = MINOR(new->unit);
new->hold_active = UNTIL_STOP;
- list_add(&new->all_mddevs, &all_mddevs);
- spin_unlock(&all_mddevs_lock);
- return new;
}
- spin_unlock(&all_mddevs_lock);
-
- new = kzalloc(sizeof(*new), GFP_KERNEL);
- if (!new)
- return NULL;
- new->unit = unit;
- if (MAJOR(unit) == MD_MAJOR)
- new->md_minor = MINOR(unit);
- else
- new->md_minor = MINOR(unit) >> MdpMinorShift;
-
- mddev_init(new);
-
- goto retry;
+ list_add(&new->all_mddevs, &all_mddevs);
+ spin_unlock(&all_mddevs_lock);
+ return new;
+out_free_new:
+ spin_unlock(&all_mddevs_lock);
+ kfree(new);
+ return mddev;
}
static struct attribute_group md_redundancy_group;
--
2.30.1
next prev parent reply other threads:[~2021-03-30 16:18 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 16:17 move bd_mutex to the gendisk Christoph Hellwig
2021-03-30 16:17 ` [PATCH 01/15] md: remove the code to flush an old instance in md_open Christoph Hellwig
2021-03-31 3:29 ` heming.zhao
2021-03-31 6:53 ` Christoph Hellwig
2021-03-30 16:17 ` [PATCH 02/15] md: factor out a mddev_find_locked helper from mddev_find Christoph Hellwig
2021-03-30 16:17 ` [PATCH 03/15] md: factor out a mddev_alloc_unit " Christoph Hellwig
2021-03-30 16:17 ` [PATCH 04/15] md: split mddev_find Christoph Hellwig
2021-03-30 16:17 ` Christoph Hellwig [this message]
2021-03-30 16:17 ` [PATCH 06/15] md: do not return existing mddevs from mddev_find_or_alloc Christoph Hellwig
2021-03-30 16:17 ` [PATCH 07/15] block: remove the -ERESTARTSYS handling in blkdev_get_by_dev Christoph Hellwig
2021-03-30 16:17 ` [PATCH 08/15] block: split __blkdev_get Christoph Hellwig
2021-03-30 16:17 ` [PATCH 09/15] block: move sync_blockdev from __blkdev_put to blkdev_put Christoph Hellwig
2021-03-30 16:17 ` [PATCH 10/15] block: move bd_mutex to struct gendisk Christoph Hellwig
2021-04-01 8:25 ` Roger Pau Monné
2021-04-08 14:29 ` Stefan Haberland
2021-03-30 16:17 ` [PATCH 11/15] block: move adjusting bd_part_count out of __blkdev_get Christoph Hellwig
2021-03-30 16:17 ` [PATCH 12/15] block: split __blkdev_put Christoph Hellwig
2021-03-30 16:17 ` [PATCH 13/15] block: move bd_part_count to struct gendisk Christoph Hellwig
2021-03-30 16:17 ` [PATCH 14/15] block: factor out a part_devt helper Christoph Hellwig
2021-03-30 16:17 ` [PATCH 15/15] block: remove bdget_disk Christoph Hellwig
2021-03-30 23:37 ` Chaitanya Kulkarni
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