From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
linux-block@vger.kernel.org,
Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Subject: [PATCH 6/9] loop: move loop_ctl_mutex locking into loop_add
Date: Wed, 23 Jun 2021 16:59:05 +0200 [thread overview]
Message-ID: <20210623145908.92973-7-hch@lst.de> (raw)
In-Reply-To: <20210623145908.92973-1-hch@lst.de>
Move acquiring and releasing loop_ctl_mutex from the callers into
loop_add.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/block/loop.c | 37 +++++++++++++------------------------
1 file changed, 13 insertions(+), 24 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d55526c355e1..01d393a60b37 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2079,9 +2079,12 @@ static int loop_add(int i)
lo = kzalloc(sizeof(*lo), GFP_KERNEL);
if (!lo)
goto out;
-
lo->lo_state = Lo_unbound;
+ err = mutex_lock_killable(&loop_ctl_mutex);
+ if (err)
+ goto out_free_dev;
+
/* allocate id, if @id >= 0, we're requesting that specific id */
if (i >= 0) {
err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL);
@@ -2091,7 +2094,7 @@ static int loop_add(int i)
err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL);
}
if (err < 0)
- goto out_free_dev;
+ goto out_unlock;
i = err;
err = -ENOMEM;
@@ -2157,12 +2160,15 @@ static int loop_add(int i)
disk->queue = lo->lo_queue;
sprintf(disk->disk_name, "loop%d", i);
add_disk(disk);
- return lo->lo_number;
+ mutex_unlock(&loop_ctl_mutex);
+ return i;
out_cleanup_tags:
blk_mq_free_tag_set(&lo->tag_set);
out_free_idr:
idr_remove(&loop_index_idr, i);
+out_unlock:
+ mutex_unlock(&loop_ctl_mutex);
out_free_dev:
kfree(lo);
out:
@@ -2222,22 +2228,7 @@ static void loop_probe(dev_t dev)
if (max_loop && idx >= max_loop)
return;
-
- mutex_lock(&loop_ctl_mutex);
loop_add(idx);
- mutex_unlock(&loop_ctl_mutex);
-}
-
-static int loop_control_add(int idx)
-{
- int ret;
-
- ret = mutex_lock_killable(&loop_ctl_mutex);
- if (ret)
- return ret;
- ret = loop_add(idx);
- mutex_unlock(&loop_ctl_mutex);
- return ret;
}
static int loop_control_remove(int idx)
@@ -2281,11 +2272,11 @@ static int loop_control_get_free(int idx)
if (ret)
return ret;
ret = loop_lookup(&lo, -1);
- if (ret < 0)
- ret = loop_add(-1);
mutex_unlock(&loop_ctl_mutex);
- return ret;
+ if (ret >= 0)
+ return ret;
+ return loop_add(-1);
}
static long loop_control_ioctl(struct file *file, unsigned int cmd,
@@ -2293,7 +2284,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
{
switch (cmd) {
case LOOP_CTL_ADD:
- return loop_control_add(parm);
+ return loop_add(parm);
case LOOP_CTL_REMOVE:
return loop_control_remove(parm);
case LOOP_CTL_GET_FREE:
@@ -2374,10 +2365,8 @@ static int __init loop_init(void)
}
/* pre-create number of devices given by config or max_loop */
- mutex_lock(&loop_ctl_mutex);
for (i = 0; i < nr; i++)
loop_add(i);
- mutex_unlock(&loop_ctl_mutex);
printk(KERN_INFO "loop: module loaded\n");
return 0;
--
2.30.2
next prev parent reply other threads:[~2021-06-23 15:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-23 14:58 loop cleanups v2 Christoph Hellwig
2021-06-23 14:59 ` [PATCH 1/9] loop: reorder loop_exit Christoph Hellwig
2021-06-23 14:59 ` [PATCH 2/9] loop: reduce loop_ctl_mutex coverage in loop_exit Christoph Hellwig
2021-06-23 14:59 ` [PATCH 3/9] loop: remove the l argument to loop_add Christoph Hellwig
2021-06-23 14:59 ` [PATCH 4/9] loop: don't call loop_lookup before adding a loop device Christoph Hellwig
2021-06-23 14:59 ` [PATCH 5/9] loop: split loop_control_ioctl Christoph Hellwig
2021-06-23 14:59 ` Christoph Hellwig [this message]
2021-06-23 14:59 ` [PATCH 7/9] loop: don't allow deleting an unspecified loop device Christoph Hellwig
2021-06-23 14:59 ` [PATCH 8/9] loop: split loop_lookup Christoph Hellwig
2021-06-23 14:59 ` [PATCH 9/9] loop: rewrite loop_exit using idr_for_each_entry Christoph Hellwig
2021-06-24 2:45 ` loop cleanups v2 Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2021-06-21 10:15 loop cleanups Christoph Hellwig
2021-06-21 10:15 ` [PATCH 6/9] loop: move loop_ctl_mutex locking into loop_add Christoph Hellwig
2021-06-21 20:16 ` Chaitanya Kulkarni
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