a0e286b6a5
lo_refcount counts how many openers a loop device has, but that count is already provided by the block layer in the bd_openers field of the whole-disk block_device. Remove lo_refcount and allow opens to succeed even on devices beeing deleted - now that ->free_disk is implemented we can handle that race gracefull and all I/O on it will just fail. Similarly there is a small race window now where loop_control_remove does not synchronize the delete vs the remove due do bd_openers not being under lo_mutex protection, but we can handle that just as gracefully. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220330052917.2566582-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
72 lines
1.5 KiB
C
72 lines
1.5 KiB
C
/*
|
|
* loop.h
|
|
*
|
|
* Written by Theodore Ts'o, 3/29/93.
|
|
*
|
|
* Copyright 1993 by Theodore Ts'o. Redistribution of this file is
|
|
* permitted under the GNU General Public License.
|
|
*/
|
|
#ifndef _LINUX_LOOP_H
|
|
#define _LINUX_LOOP_H
|
|
|
|
#include <linux/bio.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/mutex.h>
|
|
#include <uapi/linux/loop.h>
|
|
|
|
/* Possible states of device */
|
|
enum {
|
|
Lo_unbound,
|
|
Lo_bound,
|
|
Lo_rundown,
|
|
Lo_deleting,
|
|
};
|
|
|
|
struct loop_func_table;
|
|
|
|
struct loop_device {
|
|
int lo_number;
|
|
loff_t lo_offset;
|
|
loff_t lo_sizelimit;
|
|
int lo_flags;
|
|
char lo_file_name[LO_NAME_SIZE];
|
|
|
|
struct file * lo_backing_file;
|
|
struct block_device *lo_device;
|
|
|
|
gfp_t old_gfp_mask;
|
|
|
|
spinlock_t lo_lock;
|
|
int lo_state;
|
|
spinlock_t lo_work_lock;
|
|
struct workqueue_struct *workqueue;
|
|
struct work_struct rootcg_work;
|
|
struct list_head rootcg_cmd_list;
|
|
struct list_head idle_worker_list;
|
|
struct rb_root worker_tree;
|
|
struct timer_list timer;
|
|
bool use_dio;
|
|
bool sysfs_inited;
|
|
|
|
struct request_queue *lo_queue;
|
|
struct blk_mq_tag_set tag_set;
|
|
struct gendisk *lo_disk;
|
|
struct mutex lo_mutex;
|
|
bool idr_visible;
|
|
};
|
|
|
|
struct loop_cmd {
|
|
struct list_head list_entry;
|
|
bool use_aio; /* use AIO interface to handle I/O */
|
|
atomic_t ref; /* only for aio */
|
|
long ret;
|
|
struct kiocb iocb;
|
|
struct bio_vec *bvec;
|
|
struct cgroup_subsys_state *blkcg_css;
|
|
struct cgroup_subsys_state *memcg_css;
|
|
};
|
|
|
|
#endif
|