521 lines · 16.5 KB · C
RawDownload
/* SPDX-License-Identifier: GPL-2.0 *//* * Block data types and constants.  Directly include this file only to * break include dependency loop. */#ifndef __LINUX_BLK_TYPES_H#define __LINUX_BLK_TYPES_H #include <linux/types.h>#include <linux/bvec.h>#include <linux/device.h>#include <linux/ktime.h>#include <linux/rw_hint.h> struct bio_set;struct bio;struct bio_integrity_payload;struct page;struct io_context;struct cgroup_subsys_state;typedef void (bio_end_io_t) (struct bio *);struct bio_crypt_ctx; /* * The basic unit of block I/O is a sector. It is used in a number of contexts * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9 * bytes. Variables of type sector_t represent an offset or size that is a * multiple of 512 bytes. Hence these two constants. */#ifndef SECTOR_SHIFT#define SECTOR_SHIFT 9#endif#ifndef SECTOR_SIZE#define SECTOR_SIZE (1 << SECTOR_SHIFT)#endif #define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)#define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)#define SECTOR_MASK		(PAGE_SECTORS - 1) struct block_device {	sector_t		bd_start_sect;	sector_t		bd_nr_sectors;	struct gendisk *	bd_disk;	struct request_queue *	bd_queue;	struct disk_stats __percpu *bd_stats;	unsigned long		bd_stamp;	atomic_t		__bd_flags;	// partition number + flags#define BD_PARTNO		255	// lower 8 bits; assign-once#define BD_READ_ONLY		(1u<<8) // read-only policy#define BD_WRITE_HOLDER		(1u<<9)#define BD_HAS_SUBMIT_BIO	(1u<<10)#define BD_RO_WARNED		(1u<<11)#ifdef CONFIG_FAIL_MAKE_REQUEST#define BD_MAKE_IT_FAIL		(1u<<12)#endif	dev_t			bd_dev;	struct address_space	*bd_mapping;	/* page cache */ 	atomic_t		bd_openers;	spinlock_t		bd_size_lock; /* for bd_inode->i_size updates */	void *			bd_claiming;	void *			bd_holder;	const struct blk_holder_ops *bd_holder_ops;	struct mutex		bd_holder_lock;	int			bd_holders;	struct kobject		*bd_holder_dir; 	atomic_t		bd_fsfreeze_count; /* number of freeze requests */	struct mutex		bd_fsfreeze_mutex; /* serialize freeze/thaw */ 	struct partition_meta_info *bd_meta_info;	int			bd_writers;#ifdef CONFIG_SECURITY	void			*bd_security;#endif	/*	 * keep this out-of-line as it's both big and not needed in the fast	 * path	 */	struct device		bd_device;} __randomize_layout; #define bdev_whole(_bdev) \	((_bdev)->bd_disk->part0) #define dev_to_bdev(device) \	container_of((device), struct block_device, bd_device) #define bdev_kobj(_bdev) \	(&((_bdev)->bd_device.kobj)) /* * Block error status values.  See block/blk-core:blk_errors for the details. */typedef u8 __bitwise blk_status_t;typedef u16 blk_short_t;#define	BLK_STS_OK 0#define BLK_STS_NOTSUPP		((__force blk_status_t)1)#define BLK_STS_TIMEOUT		((__force blk_status_t)2)#define BLK_STS_NOSPC		((__force blk_status_t)3)#define BLK_STS_TRANSPORT	((__force blk_status_t)4)#define BLK_STS_TARGET		((__force blk_status_t)5)#define BLK_STS_RESV_CONFLICT	((__force blk_status_t)6)#define BLK_STS_MEDIUM		((__force blk_status_t)7)#define BLK_STS_PROTECTION	((__force blk_status_t)8)#define BLK_STS_RESOURCE	((__force blk_status_t)9)#define BLK_STS_IOERR		((__force blk_status_t)10) /* hack for device mapper, don't use elsewhere: */#define BLK_STS_DM_REQUEUE    ((__force blk_status_t)11) /* * BLK_STS_AGAIN should only be returned if RQF_NOWAIT is set * and the bio would block (cf bio_wouldblock_error()) */#define BLK_STS_AGAIN		((__force blk_status_t)12) /* * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if * device related resources are unavailable, but the driver can guarantee * that the queue will be rerun in the future once resources become * available again. This is typically the case for device specific * resources that are consumed for IO. If the driver fails allocating these * resources, we know that inflight (or pending) IO will free these * resource upon completion. * * This is different from BLK_STS_RESOURCE in that it explicitly references * a device specific resource. For resources of wider scope, allocation * failure can happen without having pending IO. This means that we can't * rely on request completions freeing these resources, as IO may not be in * flight. Examples of that are kernel memory allocations, DMA mappings, or * any other system wide resources. */#define BLK_STS_DEV_RESOURCE	((__force blk_status_t)13) /* * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion * path if the device returns a status indicating that too many zone resources * are currently open. The same command should be successful if resubmitted * after the number of open zones decreases below the device's limits, which is * reported in the request_queue's max_open_zones. */#define BLK_STS_ZONE_OPEN_RESOURCE	((__force blk_status_t)14) /* * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion * path if the device returns a status indicating that too many zone resources * are currently active. The same command should be successful if resubmitted * after the number of active zones decreases below the device's limits, which * is reported in the request_queue's max_active_zones. */#define BLK_STS_ZONE_ACTIVE_RESOURCE	((__force blk_status_t)15) /* * BLK_STS_OFFLINE is returned from the driver when the target device is offline * or is being taken offline. This could help differentiate the case where a * device is intentionally being shut down from a real I/O error. */#define BLK_STS_OFFLINE		((__force blk_status_t)16) /* * BLK_STS_DURATION_LIMIT is returned from the driver when the target device * aborted the command because it exceeded one of its Command Duration Limits. */#define BLK_STS_DURATION_LIMIT	((__force blk_status_t)17) /* * Invalid size or alignment. */#define BLK_STS_INVAL	((__force blk_status_t)19) /** * blk_path_error - returns true if error may be path related * @error: status the request was completed with * * Description: *     This classifies block error status into non-retryable errors and ones *     that may be successful if retried on a failover path. * * Return: *     %false - retrying failover path will not help *     %true  - may succeed if retried */static inline bool blk_path_error(blk_status_t error){	switch (error) {	case BLK_STS_NOTSUPP:	case BLK_STS_NOSPC:	case BLK_STS_TARGET:	case BLK_STS_RESV_CONFLICT:	case BLK_STS_MEDIUM:	case BLK_STS_PROTECTION:		return false;	} 	/* Anything else could be a path failure, so should be retried */	return true;} typedef __u32 __bitwise blk_opf_t; typedef unsigned int blk_qc_t;#define BLK_QC_T_NONE		-1U /* * main unit of I/O for the block layer and lower layers (ie drivers and * stacking drivers) */struct bio {	struct bio		*bi_next;	/* request queue link */	struct block_device	*bi_bdev;	blk_opf_t		bi_opf;		/* bottom bits REQ_OP, top bits						 * req_flags.						 */	unsigned short		bi_flags;	/* BIO_* below */	unsigned short		bi_ioprio;	enum rw_hint		bi_write_hint;	u8			bi_write_stream;	blk_status_t		bi_status; 	/*	 * The bvec gap bit indicates the lowest set bit in any address offset	 * between all bi_io_vecs. This field is initialized only after the bio	 * is split to the hardware limits (see bio_split_io_at()). The value	 * may be used to consider DMA optimization when performing that	 * mapping. The value is compared to a power of two mask where the	 * result depends on any bit set within the mask, so saving the lowest	 * bit is sufficient to know if any segment gap collides with the mask.	 */	u8			bi_bvec_gap_bit; 	atomic_t		__bi_remaining; 	/* The actual vec list, preserved by bio_reset() */	struct bio_vec		*bi_io_vec;	struct bvec_iter	bi_iter; 	union {		/* for polled bios: */		blk_qc_t		bi_cookie;		/* for plugged zoned writes only: */		unsigned int		__bi_nr_segments;	};	bio_end_io_t		*bi_end_io;	void			*bi_private;#ifdef CONFIG_BLK_CGROUP	/*	 * Represents the association of the css and request_queue for the bio.	 * If a bio goes direct to device, it will not have a blkg as it will	 * not have a request_queue associated with it.  The reference is put	 * on release of the bio.	 */	struct blkcg_gq		*bi_blkg;	/* Time that this bio was issued. */	u64			issue_time_ns;#ifdef CONFIG_BLK_CGROUP_IOCOST	u64			bi_iocost_cost;#endif#endif #ifdef CONFIG_BLK_INLINE_ENCRYPTION	struct bio_crypt_ctx	*bi_crypt_context;#endif #if defined(CONFIG_BLK_DEV_INTEGRITY)	struct bio_integrity_payload *bi_integrity; /* data integrity */#endif 	unsigned short		bi_vcnt;	/* how many bio_vec's */ 	/*	 * Everything starting with bi_max_vecs will be preserved by bio_reset()	 */ 	/*	 * Number of elements in `bi_io_vec` that were allocated for this bio.	 * Only used by the bio submitter to make `bio_add_page` fail once full	 * and to free the `bi_io_vec` allocation. Must not be used in drivers	 * and does not hold a useful value for cloned bios.	 */	unsigned short		bi_max_vecs; 	atomic_t		__bi_cnt;	/* pin count */ 	struct bio_set		*bi_pool;}; #define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)#define BIO_MAX_SIZE		UINT_MAX /* max value of bi_iter.bi_size */#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> SECTOR_SHIFT) static inline struct bio_vec *bio_inline_vecs(struct bio *bio){	return (struct bio_vec *)(bio + 1);} /* * bio flags */enum {	BIO_PAGE_PINNED,	/* Unpin pages in bio_release_pages() */	BIO_CLONED,		/* doesn't own data */	BIO_QUIET,		/* Make BIO Quiet */	BIO_CHAIN,		/* chained bio, ->bi_remaining in effect */	BIO_REFFED,		/* bio has elevated ->bi_cnt */	BIO_BPS_THROTTLED,	/* This bio has already been subjected to				 * throttling rules. Don't do it again. */	BIO_TRACE_COMPLETION,	/* bio_endio() should trace the final completion				 * of this bio. */	BIO_CGROUP_ACCT,	/* has been accounted to a cgroup */	BIO_QOS_THROTTLED,	/* bio went through rq_qos throttle path */	/*	 * This bio has completed bps throttling at the single tg granularity,	 * which is different from BIO_BPS_THROTTLED. When the bio is enqueued	 * into the sq->queued of the upper tg, or is about to be dispatched,	 * this flag needs to be cleared. Since blk-throttle and rq_qos are not	 * on the same hierarchical level, reuse the value.	 */	BIO_TG_BPS_THROTTLED = BIO_QOS_THROTTLED,	BIO_QOS_MERGED,		/* but went through rq_qos merge path */	BIO_REMAPPED,	BIO_ZONE_WRITE_PLUGGING, /* bio handled through zone write plugging */	BIO_EMULATES_ZONE_APPEND, /* bio emulates a zone append operation */	BIO_FLAG_LAST}; typedef __u32 __bitwise blk_mq_req_flags_t; #define REQ_OP_BITS	8#define REQ_OP_MASK	(__force blk_opf_t)((1 << REQ_OP_BITS) - 1)#define REQ_FLAG_BITS	24 /** * enum req_op - Operations common to the bio and request structures. * We use 8 bits for encoding the operation, and the remaining 24 for flags. * * The least significant bit of the operation number indicates the data * transfer direction: * *   - if the least significant bit is set transfers are TO the device *   - if the least significant bit is not set transfers are FROM the device * * If a operation does not transfer data the least significant bit has no * meaning. */enum req_op {	/** @REQ_OP_READ: read sectors from the device */	REQ_OP_READ		= (__force blk_opf_t)0,	/** @REQ_OP_WRITE: write sectors to the device */	REQ_OP_WRITE		= (__force blk_opf_t)1,	/** @REQ_OP_FLUSH: flush the volatile write cache */	REQ_OP_FLUSH		= (__force blk_opf_t)2,	/** @REQ_OP_DISCARD: discard sectors */	REQ_OP_DISCARD		= (__force blk_opf_t)3,	/** @REQ_OP_SECURE_ERASE: securely erase sectors */	REQ_OP_SECURE_ERASE	= (__force blk_opf_t)5,	/** @REQ_OP_ZONE_APPEND: write data at the current zone write pointer */	REQ_OP_ZONE_APPEND	= (__force blk_opf_t)7,	/** @REQ_OP_WRITE_ZEROES: write the zero filled sector many times */	REQ_OP_WRITE_ZEROES	= (__force blk_opf_t)9,	/** @REQ_OP_ZONE_OPEN: Open a zone */	REQ_OP_ZONE_OPEN	= (__force blk_opf_t)11,	/** @REQ_OP_ZONE_CLOSE: Close a zone */	REQ_OP_ZONE_CLOSE	= (__force blk_opf_t)13,	/** @REQ_OP_ZONE_FINISH: Transition a zone to full */	REQ_OP_ZONE_FINISH	= (__force blk_opf_t)15,	/** @REQ_OP_ZONE_RESET: reset a zone write pointer */	REQ_OP_ZONE_RESET	= (__force blk_opf_t)17,	/** @REQ_OP_ZONE_RESET_ALL: reset all the zone present on the device */	REQ_OP_ZONE_RESET_ALL	= (__force blk_opf_t)19, 	/* Driver private requests */	/* private: */	REQ_OP_DRV_IN		= (__force blk_opf_t)34,	REQ_OP_DRV_OUT		= (__force blk_opf_t)35, 	REQ_OP_LAST		= (__force blk_opf_t)36,}; /* Keep cmd_flag_name[] in sync with the definitions below */enum req_flag_bits {	__REQ_FAILFAST_DEV =	/* no driver retries of device errors */		REQ_OP_BITS,	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */	__REQ_FAILFAST_DRIVER,	/* no driver retries of driver errors */	__REQ_SYNC,		/* request is sync (sync write or read) */	__REQ_META,		/* metadata io request */	__REQ_PRIO,		/* boost priority in cfq */	__REQ_NOMERGE,		/* don't touch this for merging */	__REQ_IDLE,		/* anticipate more IO after this one */	__REQ_INTEGRITY,	/* I/O includes block integrity payload */	__REQ_FUA,		/* forced unit access */	__REQ_PREFLUSH,		/* request for cache flush */	__REQ_RAHEAD,		/* read ahead, can fail anytime */	__REQ_BACKGROUND,	/* background IO */	__REQ_NOWAIT,           /* Don't wait if request will block */	__REQ_POLLED,		/* caller polls for completion using bio_poll */	__REQ_ALLOC_CACHE,	/* allocate IO from cache if available */	__REQ_SWAP,		/* swap I/O */	__REQ_DRV,		/* for driver use */	__REQ_FS_PRIVATE,	/* for file system (submitter) use */	__REQ_ATOMIC,		/* for atomic write operations */	/*	 * Command specific flags, keep last:	 */	/* for REQ_OP_WRITE_ZEROES: */	__REQ_NOUNMAP,		/* do not free blocks when zeroing */ 	__REQ_NR_BITS,		/* stops here */}; #define REQ_FAILFAST_DEV	\			(__force blk_opf_t)(1ULL << __REQ_FAILFAST_DEV)#define REQ_FAILFAST_TRANSPORT	\			(__force blk_opf_t)(1ULL << __REQ_FAILFAST_TRANSPORT)#define REQ_FAILFAST_DRIVER	\			(__force blk_opf_t)(1ULL << __REQ_FAILFAST_DRIVER)#define REQ_SYNC	(__force blk_opf_t)(1ULL << __REQ_SYNC)#define REQ_META	(__force blk_opf_t)(1ULL << __REQ_META)#define REQ_PRIO	(__force blk_opf_t)(1ULL << __REQ_PRIO)#define REQ_NOMERGE	(__force blk_opf_t)(1ULL << __REQ_NOMERGE)#define REQ_IDLE	(__force blk_opf_t)(1ULL << __REQ_IDLE)#define REQ_INTEGRITY	(__force blk_opf_t)(1ULL << __REQ_INTEGRITY)#define REQ_FUA		(__force blk_opf_t)(1ULL << __REQ_FUA)#define REQ_PREFLUSH	(__force blk_opf_t)(1ULL << __REQ_PREFLUSH)#define REQ_RAHEAD	(__force blk_opf_t)(1ULL << __REQ_RAHEAD)#define REQ_BACKGROUND	(__force blk_opf_t)(1ULL << __REQ_BACKGROUND)#define REQ_NOWAIT	(__force blk_opf_t)(1ULL << __REQ_NOWAIT)#define REQ_POLLED	(__force blk_opf_t)(1ULL << __REQ_POLLED)#define REQ_ALLOC_CACHE	(__force blk_opf_t)(1ULL << __REQ_ALLOC_CACHE)#define REQ_SWAP	(__force blk_opf_t)(1ULL << __REQ_SWAP)#define REQ_DRV		(__force blk_opf_t)(1ULL << __REQ_DRV)#define REQ_FS_PRIVATE	(__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE)#define REQ_ATOMIC	(__force blk_opf_t)(1ULL << __REQ_ATOMIC) #define REQ_NOUNMAP	(__force blk_opf_t)(1ULL << __REQ_NOUNMAP) #define REQ_FAILFAST_MASK \	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) #define REQ_NOMERGE_FLAGS \	(REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA) enum stat_group {	STAT_READ,	STAT_WRITE,	STAT_DISCARD,	STAT_FLUSH, 	NR_STAT_GROUPS}; static inline enum req_op bio_op(const struct bio *bio){	return bio->bi_opf & REQ_OP_MASK;} static inline bool op_is_write(blk_opf_t op){	return !!(op & (__force blk_opf_t)1);} /* * Check if the bio or request is one that needs special treatment in the * flush state machine. */static inline bool op_is_flush(blk_opf_t op){	return op & (REQ_FUA | REQ_PREFLUSH);} /* * Reads are always treated as synchronous, as are requests with the FUA or * PREFLUSH flag.  Other operations may be marked as synchronous using the * REQ_SYNC flag. */static inline bool op_is_sync(blk_opf_t op){	return (op & REQ_OP_MASK) == REQ_OP_READ ||		(op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));} static inline bool op_is_discard(blk_opf_t op){	return (op & REQ_OP_MASK) == REQ_OP_DISCARD;} /* * Check if a bio or request operation is a zone management operation. */static inline bool op_is_zone_mgmt(enum req_op op){	switch (op & REQ_OP_MASK) {	case REQ_OP_ZONE_RESET:	case REQ_OP_ZONE_RESET_ALL:	case REQ_OP_ZONE_OPEN:	case REQ_OP_ZONE_CLOSE:	case REQ_OP_ZONE_FINISH:		return true;

Lines 1–500 of 521.