diff options
Diffstat (limited to 'block/bdev.c')
| -rw-r--r-- | block/bdev.c | 71 |
1 files changed, 61 insertions, 10 deletions
diff --git a/block/bdev.c b/block/bdev.c index 04dba25b00..750aec178b 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -292,7 +292,7 @@ EXPORT_SYMBOL(thaw_bdev); */ static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); -static struct kmem_cache * bdev_cachep __read_mostly; +static struct kmem_cache *bdev_cachep __ro_after_init; static struct inode *bdev_alloc_inode(struct super_block *sb) { @@ -361,13 +361,13 @@ static struct file_system_type bd_type = { .kill_sb = kill_anon_super, }; -struct super_block *blockdev_superblock __read_mostly; +struct super_block *blockdev_superblock __ro_after_init; EXPORT_SYMBOL_GPL(blockdev_superblock); void __init bdev_cache_init(void) { int err; - static struct vfsmount *bd_mnt; + static struct vfsmount *bd_mnt __ro_after_init; bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| @@ -831,6 +831,28 @@ put_blkdev: } EXPORT_SYMBOL(blkdev_get_by_dev); +struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops) +{ + struct bdev_handle *handle = kmalloc(sizeof(*handle), GFP_KERNEL); + struct block_device *bdev; + + if (!handle) + return ERR_PTR(-ENOMEM); + bdev = blkdev_get_by_dev(dev, mode, holder, hops); + if (IS_ERR(bdev)) { + kfree(handle); + return ERR_CAST(bdev); + } + handle->bdev = bdev; + handle->holder = holder; + if (holder) + mode |= BLK_OPEN_EXCL; + handle->mode = mode; + return handle; +} +EXPORT_SYMBOL(bdev_open_by_dev); + /** * blkdev_get_by_path - open a block device by name * @path: path to the block device to open @@ -869,6 +891,28 @@ struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode, } EXPORT_SYMBOL(blkdev_get_by_path); +struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode, + void *holder, const struct blk_holder_ops *hops) +{ + struct bdev_handle *handle; + dev_t dev; + int error; + + error = lookup_bdev(path, &dev); + if (error) + return ERR_PTR(error); + + handle = bdev_open_by_dev(dev, mode, holder, hops); + if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) && + bdev_read_only(handle->bdev)) { + bdev_release(handle); + return ERR_PTR(-EACCES); + } + + return handle; +} +EXPORT_SYMBOL(bdev_open_by_path); + void blkdev_put(struct block_device *bdev, void *holder) { struct gendisk *disk = bdev->bd_disk; @@ -905,6 +949,13 @@ void blkdev_put(struct block_device *bdev, void *holder) } EXPORT_SYMBOL(blkdev_put); +void bdev_release(struct bdev_handle *handle) +{ + blkdev_put(handle->bdev, handle->holder); + kfree(handle); +} +EXPORT_SYMBOL(bdev_release); + /** * lookup_bdev() - Look up a struct block_device by name. * @pathname: Name of the block device in the filesystem. @@ -963,20 +1014,20 @@ void bdev_mark_dead(struct block_device *bdev, bool surprise) mutex_lock(&bdev->bd_holder_lock); if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead) bdev->bd_holder_ops->mark_dead(bdev, surprise); - else + else { + mutex_unlock(&bdev->bd_holder_lock); sync_blockdev(bdev); - mutex_unlock(&bdev->bd_holder_lock); + } invalidate_bdev(bdev); } -#ifdef CONFIG_DASD_MODULE /* - * Drivers should not use this directly, but the DASD driver has historically - * had a shutdown to offline mode that doesn't actually remove the gendisk - * that otherwise looks a lot like a safe device removal. + * New drivers should not use this directly. There are some drivers however + * that needs this for historical reasons. For example, the DASD driver has + * historically had a shutdown to offline mode that doesn't actually remove the + * gendisk that otherwise looks a lot like a safe device removal. */ EXPORT_SYMBOL_GPL(bdev_mark_dead); -#endif void sync_bdevs(bool wait) { |