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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889/* SPDX-License-Identifier: GPL-2.0 *//* * Copyright (c) 2014-2026 Christoph Hellwig. * * Support for exportfs-based layout grants for direct block device access. */#ifndef LINUX_EXPORTFS_BLOCK_H#define LINUX_EXPORTFS_BLOCK_H 1
#include <linux/blkdev.h>#include <linux/exportfs.h>#include <linux/fs.h>
struct inode;struct iomap;struct super_block;
/* * There are the two types of block-style layout support: * - In-band implies a device identified by a unique cookie inside the actual * device address space checked by the ->get_uuid method as used by the pNFS * block layout. This is a bit dangerous and deprecated. * - Out of band implies identification by out of band unique identifiers * specified by the storage protocol, which is much safer and used by the * pNFS SCSI/NVMe layouts. */typedef unsigned int __bitwise expfs_block_layouts_t;#define EXPFS_BLOCK_FLAG(__bit) \ ((__force expfs_block_layouts_t)(1u << __bit))#define EXPFS_BLOCK_IN_BAND_ID EXPFS_BLOCK_FLAG(0)#define EXPFS_BLOCK_OUT_OF_BAND_ID EXPFS_BLOCK_FLAG(1)
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 boolexportfs_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_OPSstatic inline expfs_block_layouts_texportfs_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);}#elsestatic inline expfs_block_layouts_texportfs_layouts_supported(struct super_block *sb){ return 0;}#endif /* CONFIG_EXPORTFS_BLOCK_OPS */
#endif /* LINUX_EXPORTFS_BLOCK_H */