include/linux/exportfs_block.h

Source file repositories/reference/linux-study-clean/include/linux/exportfs_block.h

File Facts

System
Linux kernel
Corpus path
include/linux/exportfs_block.h
Extension
.h
Size
2569 bytes
Lines
89
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct exportfs_block_ops {
	/*
	 * Returns the EXPFS_BLOCK_* bitmap of supported layout types.
	 */
	expfs_block_layouts_t (*layouts_supported)(struct super_block *sb);

	/*
	 * Get the in-band device unique signature exposed to clients.
	 */
	int (*get_uuid)(struct super_block *sb, u8 *buf, u32 *len, u64 *offset);

	/*
	 * Map blocks for direct block access.
	 * If @write is %true, also allocate the blocks for the range if needed.
	 */
	int (*map_blocks)(struct inode *inode, loff_t offset, u64 len,
			struct iomap *iomap, bool write,
			u32 *device_generation);

	/*
	 * Commit blocks previously handed out by ->map_blocks and written to by
	 * the client.
	 */
	int (*commit_blocks)(struct inode *inode, struct iomap *iomaps,
			int nr_iomaps, loff_t new_size);
};

static inline bool
exportfs_bdev_supports_out_of_band_id(struct block_device *bdev)
{
	return bdev->bd_disk->fops->pr_ops &&
		bdev->bd_disk->fops->get_unique_id;
}

#ifdef CONFIG_EXPORTFS_BLOCK_OPS
static inline expfs_block_layouts_t
exportfs_layouts_supported(struct super_block *sb)
{
	const struct exportfs_block_ops *bops = sb->s_export_op->block_ops;

	if (!bops ||
	    !bops->layouts_supported ||
	    WARN_ON_ONCE(!bops->map_blocks) ||
	    WARN_ON_ONCE(!bops->commit_blocks))
		return 0;
	return bops->layouts_supported(sb);
}
#else
static inline expfs_block_layouts_t
exportfs_layouts_supported(struct super_block *sb)
{
	return 0;
}
#endif /* CONFIG_EXPORTFS_BLOCK_OPS */

#endif /* LINUX_EXPORTFS_BLOCK_H */

Annotation

Implementation Notes