From: Greg Kroah-Hartman gregkh@linuxfoundation.org
This reverts commit b3f3107fbd928fed6e4fecbe3da2ed5f43216439 which is commit 310ca162d779efee8a2dc3731439680f3e9c1e86 upstream.
Jan Kara has reported seeing problems with this patch applied, as has Salvatore Bonaccorso, so let's drop it for now.
Reported-by: Salvatore Bonaccorso carnil@debian.org Reported-by: Jan Kara jack@suse.cz Cc: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/loop.c | 42 +++++++++++++++++++++--------------------- drivers/block/loop.h | 1 + 2 files changed, 22 insertions(+), 21 deletions(-)
--- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -82,7 +82,6 @@
static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_index_mutex); -static DEFINE_MUTEX(loop_ctl_mutex);
static int max_part; static int part_shift; @@ -1045,7 +1044,7 @@ static int loop_clr_fd(struct loop_devic */ if (atomic_read(&lo->lo_refcnt) > 1) { lo->lo_flags |= LO_FLAGS_AUTOCLEAR; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; }
@@ -1094,12 +1093,12 @@ static int loop_clr_fd(struct loop_devic if (!part_shift) lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; loop_unprepare_queue(lo); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); /* - * Need not hold loop_ctl_mutex to fput backing file. - * Calling fput holding loop_ctl_mutex triggers a circular + * Need not hold lo_ctl_mutex to fput backing file. + * Calling fput holding lo_ctl_mutex triggers a circular * lock dependency possibility warning as fput can take - * bd_mutex which is usually taken before loop_ctl_mutex. + * bd_mutex which is usually taken before lo_ctl_mutex. */ fput(filp); return 0; @@ -1362,7 +1361,7 @@ static int lo_ioctl(struct block_device struct loop_device *lo = bdev->bd_disk->private_data; int err;
- mutex_lock_nested(&loop_ctl_mutex, 1); + mutex_lock_nested(&lo->lo_ctl_mutex, 1); switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, mode, bdev, arg); @@ -1371,7 +1370,7 @@ static int lo_ioctl(struct block_device err = loop_change_fd(lo, bdev, arg); break; case LOOP_CLR_FD: - /* loop_clr_fd would have unlocked loop_ctl_mutex on success */ + /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ err = loop_clr_fd(lo); if (!err) goto out_unlocked; @@ -1407,7 +1406,7 @@ static int lo_ioctl(struct block_device default: err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex);
out_unlocked: return err; @@ -1540,16 +1539,16 @@ static int lo_compat_ioctl(struct block_
switch(cmd) { case LOOP_SET_STATUS: - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); err = loop_set_status_compat( lo, (const struct compat_loop_info __user *) arg); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; case LOOP_GET_STATUS: - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); err = loop_get_status_compat( lo, (struct compat_loop_info __user *) arg); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; case LOOP_SET_CAPACITY: case LOOP_CLR_FD: @@ -1593,7 +1592,7 @@ static void __lo_release(struct loop_dev if (atomic_dec_return(&lo->lo_refcnt)) return;
- mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { /* * In autoclear mode, stop the loop thread @@ -1610,7 +1609,7 @@ static void __lo_release(struct loop_dev loop_flush(lo); }
- mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); }
static void lo_release(struct gendisk *disk, fmode_t mode) @@ -1656,10 +1655,10 @@ static int unregister_transfer_cb(int id struct loop_device *lo = ptr; struct loop_func_table *xfer = data;
- mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_encryption == xfer) loop_release_xfer(lo); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; }
@@ -1821,6 +1820,7 @@ static int loop_add(struct loop_device * if (!part_shift) disk->flags |= GENHD_FL_NO_PART_SCAN; disk->flags |= GENHD_FL_EXT_DEVT; + mutex_init(&lo->lo_ctl_mutex); atomic_set(&lo->lo_refcnt, 0); lo->lo_number = i; spin_lock_init(&lo->lo_lock); @@ -1933,19 +1933,19 @@ static long loop_control_ioctl(struct fi ret = loop_lookup(&lo, parm); if (ret < 0) break; - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_state != Lo_unbound) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; } if (atomic_read(&lo->lo_refcnt) > 0) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; } lo->lo_disk->private_data = NULL; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); idr_remove(&loop_index_idr, lo->lo_number); loop_remove(lo); break; --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -55,6 +55,7 @@ struct loop_device {
spinlock_t lo_lock; int lo_state; + struct mutex lo_ctl_mutex; struct kthread_worker worker; struct task_struct *worker_task; bool use_dio;