diff options
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r-- | drivers/block/loop.c | 51 |
1 files changed, 45 insertions, 6 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index edbaac6c0573..2621ed2ce6d2 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -392,8 +392,7 @@ lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct loop_device *lo = p->lo; struct page *page = buf->page; sector_t IV; - size_t size; - int ret; + int size, ret; ret = buf->ops->confirm(pipe, buf); if (unlikely(ret)) @@ -475,10 +474,35 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) int ret; pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; - if (bio_rw(bio) == WRITE) + + if (bio_rw(bio) == WRITE) { + int barrier = bio_barrier(bio); + struct file *file = lo->lo_backing_file; + + if (barrier) { + if (unlikely(!file->f_op->fsync)) { + ret = -EOPNOTSUPP; + goto out; + } + + ret = vfs_fsync(file, file->f_path.dentry, 0); + if (unlikely(ret)) { + ret = -EIO; + goto out; + } + } + ret = lo_send(lo, bio, pos); - else + + if (barrier && !ret) { + ret = vfs_fsync(file, file->f_path.dentry, 0); + if (unlikely(ret)) + ret = -EIO; + } + } else ret = lo_receive(lo, bio, lo->lo_blocksize, pos); + +out: return ret; } @@ -827,6 +851,9 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, lo->lo_queue->queuedata = lo; lo->lo_queue->unplug_fn = loop_unplug; + if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) + blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN, NULL); + set_capacity(lo->lo_disk, size); bd_set_size(bdev, size << 9); @@ -942,11 +969,18 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) bd_set_size(bdev, 0); mapping_set_gfp_mask(filp->f_mapping, gfp); lo->lo_state = Lo_unbound; - fput(filp); /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); if (max_part > 0) ioctl_by_bdev(bdev, BLKRRPART, 0); + mutex_unlock(&lo->lo_ctl_mutex); + /* + * 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 lo_ctl_mutex. + */ + fput(filp); return 0; } @@ -1164,7 +1198,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, struct loop_device *lo = bdev->bd_disk->private_data; int err; - mutex_lock(&lo->lo_ctl_mutex); + mutex_lock_nested(&lo->lo_ctl_mutex, 1); switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, mode, bdev, arg); @@ -1173,7 +1207,10 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, err = loop_change_fd(lo, bdev, arg); break; case LOOP_CLR_FD: + /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ err = loop_clr_fd(lo, bdev); + if (!err) + goto out_unlocked; break; case LOOP_SET_STATUS: err = loop_set_status_old(lo, (struct loop_info __user *) arg); @@ -1191,6 +1228,8 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } mutex_unlock(&lo->lo_ctl_mutex); + +out_unlocked: return err; } |