diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/block_dev.c | 49 | ||||
| -rw-r--r-- | fs/direct-io.c | 3 |
2 files changed, 33 insertions, 19 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 4a181fcb5175..fe09ef9c21f3 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1058,6 +1058,27 @@ retry: return 0; } +static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) +{ + struct gendisk *disk = get_gendisk(bdev->bd_dev, partno); + + if (!disk) + return NULL; + /* + * Now that we hold gendisk reference we make sure bdev we looked up is + * not stale. If it is, it means device got removed and created before + * we looked up gendisk and we fail open in such case. Associating + * unhashed bdev with newly created gendisk could lead to two bdevs + * (and thus two independent caches) being associated with one device + * which is bad. + */ + if (inode_unhashed(bdev->bd_inode)) { + put_disk_and_module(disk); + return NULL; + } + return disk; +} + /** * bd_start_claiming - start claiming a block device * @bdev: block device of interest @@ -1094,7 +1115,7 @@ static struct block_device *bd_start_claiming(struct block_device *bdev, * @bdev might not have been initialized properly yet, look up * and grab the outer block device the hard way. */ - disk = get_gendisk(bdev->bd_dev, &partno); + disk = bdev_get_gendisk(bdev, &partno); if (!disk) return ERR_PTR(-ENXIO); @@ -1111,8 +1132,7 @@ static struct block_device *bd_start_claiming(struct block_device *bdev, else whole = bdgrab(bdev); - module_put(disk->fops->owner); - put_disk(disk); + put_disk_and_module(disk); if (!whole) return ERR_PTR(-ENOMEM); @@ -1407,10 +1427,10 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) { struct gendisk *disk; - struct module *owner; int ret; int partno; int perm = 0; + bool first_open = false; if (mode & FMODE_READ) perm |= MAY_READ; @@ -1430,14 +1450,14 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) restart: ret = -ENXIO; - disk = get_gendisk(bdev->bd_dev, &partno); + disk = bdev_get_gendisk(bdev, &partno); if (!disk) goto out; - owner = disk->fops->owner; disk_block_events(disk); mutex_lock_nested(&bdev->bd_mutex, for_part); if (!bdev->bd_openers) { + first_open = true; bdev->bd_disk = disk; bdev->bd_queue = disk->queue; bdev->bd_contains = bdev; @@ -1463,8 +1483,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_queue = NULL; mutex_unlock(&bdev->bd_mutex); disk_unblock_events(disk); - put_disk(disk); - module_put(owner); + put_disk_and_module(disk); goto restart; } } @@ -1524,15 +1543,15 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (ret) goto out_unlock_bdev; } - /* only one opener holds refs to the module and disk */ - put_disk(disk); - module_put(owner); } bdev->bd_openers++; if (for_part) bdev->bd_part_count++; mutex_unlock(&bdev->bd_mutex); disk_unblock_events(disk); + /* only one opener holds refs to the module and disk */ + if (!first_open) + put_disk_and_module(disk); return 0; out_clear: @@ -1546,8 +1565,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) out_unlock_bdev: mutex_unlock(&bdev->bd_mutex); disk_unblock_events(disk); - put_disk(disk); - module_put(owner); + put_disk_and_module(disk); out: bdput(bdev); @@ -1770,8 +1788,6 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) disk->fops->release(disk, mode); } if (!bdev->bd_openers) { - struct module *owner = disk->fops->owner; - disk_put_part(bdev->bd_part); bdev->bd_part = NULL; bdev->bd_disk = NULL; @@ -1779,8 +1795,7 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) victim = bdev->bd_contains; bdev->bd_contains = NULL; - put_disk(disk); - module_put(owner); + put_disk_and_module(disk); } mutex_unlock(&bdev->bd_mutex); bdput(bdev); diff --git a/fs/direct-io.c b/fs/direct-io.c index a0ca9e48e993..1357ef563893 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1274,8 +1274,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, */ if (dio->is_async && iov_iter_rw(iter) == WRITE) { retval = 0; - if ((iocb->ki_filp->f_flags & O_DSYNC) || - IS_SYNC(iocb->ki_filp->f_mapping->host)) + if (iocb->ki_flags & IOCB_DSYNC) retval = dio_set_defer_completion(dio); else if (!dio->inode->i_sb->s_dio_done_wq) { /* |