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
Subject: [PATCH 5/9] loop: split loop_control_ioctl
Date: Mon, 21 Jun 2021 12:15:43 +0200 [thread overview]
Message-ID: <20210621101547.3764003-6-hch@lst.de> (raw)
In-Reply-To: <20210621101547.3764003-1-hch@lst.de>
Split loop_control_ioctl into a helper for each command. This keeps the
code nicely separated for the upcoming locking changes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/block/loop.c | 93 ++++++++++++++++++++++++++++----------------
1 file changed, 60 insertions(+), 33 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index b1e7e420563b..d55526c355e1 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2228,8 +2228,51 @@ static void loop_probe(dev_t dev)
mutex_unlock(&loop_ctl_mutex);
}
-static long loop_control_ioctl(struct file *file, unsigned int cmd,
- unsigned long parm)
+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)
+{
+ struct loop_device *lo;
+ int ret;
+
+ ret = mutex_lock_killable(&loop_ctl_mutex);
+ if (ret)
+ return ret;
+
+ ret = loop_lookup(&lo, idx);
+ if (ret < 0)
+ goto out_unlock_ctrl;
+
+ ret = mutex_lock_killable(&lo->lo_mutex);
+ if (ret)
+ goto out_unlock_ctrl;
+ if (lo->lo_state != Lo_unbound ||
+ atomic_read(&lo->lo_refcnt) > 0) {
+ mutex_unlock(&lo->lo_mutex);
+ ret = -EBUSY;
+ goto out_unlock_ctrl;
+ }
+ lo->lo_state = Lo_deleting;
+ mutex_unlock(&lo->lo_mutex);
+
+ idr_remove(&loop_index_idr, lo->lo_number);
+ loop_remove(lo);
+out_unlock_ctrl:
+ mutex_unlock(&loop_ctl_mutex);
+ return ret;
+}
+
+static int loop_control_get_free(int idx)
{
struct loop_device *lo;
int ret;
@@ -2237,43 +2280,27 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
ret = mutex_lock_killable(&loop_ctl_mutex);
if (ret)
return ret;
+ ret = loop_lookup(&lo, -1);
+ if (ret < 0)
+ ret = loop_add(-1);
+ mutex_unlock(&loop_ctl_mutex);
+
+ return ret;
+}
- ret = -ENOSYS;
+static long loop_control_ioctl(struct file *file, unsigned int cmd,
+ unsigned long parm)
+{
switch (cmd) {
case LOOP_CTL_ADD:
- ret = loop_add(parm);
- break;
+ return loop_control_add(parm);
case LOOP_CTL_REMOVE:
- ret = loop_lookup(&lo, parm);
- if (ret < 0)
- break;
- ret = mutex_lock_killable(&lo->lo_mutex);
- if (ret)
- break;
- if (lo->lo_state != Lo_unbound) {
- ret = -EBUSY;
- mutex_unlock(&lo->lo_mutex);
- break;
- }
- if (atomic_read(&lo->lo_refcnt) > 0) {
- ret = -EBUSY;
- mutex_unlock(&lo->lo_mutex);
- break;
- }
- lo->lo_state = Lo_deleting;
- mutex_unlock(&lo->lo_mutex);
- idr_remove(&loop_index_idr, lo->lo_number);
- loop_remove(lo);
- break;
+ return loop_control_remove(parm);
case LOOP_CTL_GET_FREE:
- ret = loop_lookup(&lo, -1);
- if (ret >= 0)
- break;
- ret = loop_add(-1);
+ return loop_control_get_free(parm);
+ default:
+ return -ENOSYS;
}
- mutex_unlock(&loop_ctl_mutex);
-
- return ret;
}
static const struct file_operations loop_ctl_fops = {
--
2.30.2
next prev parent reply other threads:[~2021-06-21 10:31 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-21 10:15 loop cleanups Christoph Hellwig
2021-06-21 10:15 ` [PATCH 1/9] loop: reorder loop_exit Christoph Hellwig
2021-06-21 20:04 ` Chaitanya Kulkarni
2021-06-21 10:15 ` [PATCH 2/9] loop: reduce loop_ctl_mutex coverage in loop_exit Christoph Hellwig
2021-06-21 20:07 ` Chaitanya Kulkarni
2021-06-21 10:15 ` [PATCH 3/9] loop: remove the l argument to loop_add Christoph Hellwig
2021-06-21 20:09 ` Chaitanya Kulkarni
2021-06-21 10:15 ` [PATCH 4/9] loop: don't call loop_lookup before adding a loop device Christoph Hellwig
2021-06-21 10:15 ` Christoph Hellwig [this message]
2021-06-21 20:14 ` [PATCH 5/9] loop: split loop_control_ioctl Chaitanya Kulkarni
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
2021-06-21 10:15 ` [PATCH 7/9] loop: don't allow deleting an unspecified loop device Christoph Hellwig
2021-06-21 10:15 ` [PATCH 8/9] loop: split loop_lookup Christoph Hellwig
2021-06-21 10:15 ` [PATCH 9/9] loop: rewrite loop_exit using idr_for_each_entry Christoph Hellwig
2021-06-21 20:20 ` Chaitanya Kulkarni
2021-06-22 11:15 ` loop cleanups Tetsuo Handa
2021-06-23 14:41 ` Christoph Hellwig
2021-06-23 14:58 loop cleanups v2 Christoph Hellwig
2021-06-23 14:59 ` [PATCH 5/9] loop: split loop_control_ioctl Christoph Hellwig
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