malhuda/msm-4.14
1
0
Fork 0
mirror of https://github.com/rd-stuffs/msm-4.14.git synced 2025-02-20 11:45:48 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

loop: Get rid of loop_index_mutex

Browse Source 
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@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jan Kara 2018-11-08 14:01:04 +01:00 committed by Greg Kroah-Hartman
parent f1e81ba8a3
commit c1e63df4f3
1 changed files with 20 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/block/loop.c
View File

@ -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_device *bdev, fmode_t mode,
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 *bdev, fmode_t mode)
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 *disk, fmode_t mode)
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 *disk, fmode_t mode)
*/
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 *disk, fmode_t mode)
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 dev, int *part, void *data)
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 dev, int *part, void *data)
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 file *file, unsigned int cmd,
unsigned long parm)
{
struct loop_device *lo;
int ret = -ENOSYS;
int ret;
mutex_lock(&loop_index_mutex);
ret = mutex_lock_killable(&loop_ctl_mutex);
if (ret)
return ret;
ret = -ENOSYS;
switch (cmd) {
case LOOP_CTL_ADD:
ret = loop_lookup(&lo, parm);
@ -1960,7 +1963,6 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
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 file *file, unsigned int cmd,
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 file *file, unsigned int cmd,
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;