[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20190121122503.363013965@linuxfoundation.org>
Date: Mon, 21 Jan 2019 14:44:21 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Jan Kara <jack@...e.cz>,
Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 4.14 56/59] loop: Get rid of loop_index_mutex
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jan Kara <jack@...e.cz>
commit 0a42e99b58a208839626465af194cfe640ef9493 upstream.
Now that loop_ctl_mutex is global, just get rid of loop_index_mutex as
there is no good reason to keep these two separate and it just
complicates the locking.
Signed-off-by: Jan Kara <jack@...e.cz>
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/block/loop.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -81,7 +81,6 @@
#include <linux/uaccess.h>
static DEFINE_IDR(loop_index_idr);
-static DEFINE_MUTEX(loop_index_mutex);
static DEFINE_MUTEX(loop_ctl_mutex);
static int max_part;
@@ -1588,9 +1587,11 @@ static int lo_compat_ioctl(struct block_
static int lo_open(struct block_device *bdev, fmode_t mode)
{
struct loop_device *lo;
- int err = 0;
+ int err;
- mutex_lock(&loop_index_mutex);
+ err = mutex_lock_killable(&loop_ctl_mutex);
+ if (err)
+ return err;
lo = bdev->bd_disk->private_data;
if (!lo) {
err = -ENXIO;
@@ -1599,7 +1600,7 @@ static int lo_open(struct block_device *
atomic_inc(&lo->lo_refcnt);
out:
- mutex_unlock(&loop_index_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return err;
}
@@ -1608,12 +1609,11 @@ static void lo_release(struct gendisk *d
struct loop_device *lo;
int err;
- mutex_lock(&loop_index_mutex);
+ mutex_lock(&loop_ctl_mutex);
lo = disk->private_data;
if (atomic_dec_return(&lo->lo_refcnt))
- goto unlock_index;
+ goto out_unlock;
- mutex_lock(&loop_ctl_mutex);
if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
/*
* In autoclear mode, stop the loop thread
@@ -1621,7 +1621,7 @@ static void lo_release(struct gendisk *d
*/
err = loop_clr_fd(lo);
if (!err)
- goto unlock_index;
+ return;
} else if (lo->lo_state == Lo_bound) {
/*
* Otherwise keep thread (if running) and config,
@@ -1631,9 +1631,8 @@ static void lo_release(struct gendisk *d
blk_mq_unfreeze_queue(lo->lo_queue);
}
+out_unlock:
mutex_unlock(&loop_ctl_mutex);
-unlock_index:
- mutex_unlock(&loop_index_mutex);
}
static const struct block_device_operations lo_fops = {
@@ -1926,7 +1925,7 @@ static struct kobject *loop_probe(dev_t
struct kobject *kobj;
int err;
- mutex_lock(&loop_index_mutex);
+ mutex_lock(&loop_ctl_mutex);
err = loop_lookup(&lo, MINOR(dev) >> part_shift);
if (err < 0)
err = loop_add(&lo, MINOR(dev) >> part_shift);
@@ -1934,7 +1933,7 @@ static struct kobject *loop_probe(dev_t
kobj = NULL;
else
kobj = get_disk(lo->lo_disk);
- mutex_unlock(&loop_index_mutex);
+ mutex_unlock(&loop_ctl_mutex);
*part = 0;
return kobj;
@@ -1944,9 +1943,13 @@ static long loop_control_ioctl(struct fi
unsigned long parm)
{
struct loop_device *lo;
- int ret = -ENOSYS;
+ int ret;
+
+ ret = mutex_lock_killable(&loop_ctl_mutex);
+ if (ret)
+ return ret;
- mutex_lock(&loop_index_mutex);
+ ret = -ENOSYS;
switch (cmd) {
case LOOP_CTL_ADD:
ret = loop_lookup(&lo, parm);
@@ -1960,7 +1963,6 @@ static long loop_control_ioctl(struct fi
ret = loop_lookup(&lo, parm);
if (ret < 0)
break;
- mutex_lock(&loop_ctl_mutex);
if (lo->lo_state != Lo_unbound) {
ret = -EBUSY;
mutex_unlock(&loop_ctl_mutex);
@@ -1972,7 +1974,6 @@ static long loop_control_ioctl(struct fi
break;
}
lo->lo_disk->private_data = NULL;
- mutex_unlock(&loop_ctl_mutex);
idr_remove(&loop_index_idr, lo->lo_number);
loop_remove(lo);
break;
@@ -1982,7 +1983,7 @@ static long loop_control_ioctl(struct fi
break;
ret = loop_add(&lo, -1);
}
- mutex_unlock(&loop_index_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return ret;
}
@@ -2066,10 +2067,10 @@ static int __init loop_init(void)
THIS_MODULE, loop_probe, NULL, NULL);
/* pre-create number of devices given by config or max_loop */
- mutex_lock(&loop_index_mutex);
+ mutex_lock(&loop_ctl_mutex);
for (i = 0; i < nr; i++)
loop_add(&lo, i);
- mutex_unlock(&loop_index_mutex);
+ mutex_unlock(&loop_ctl_mutex);
printk(KERN_INFO "loop: module loaded\n");
return 0;
Powered by blists - more mailing lists