swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 4f5cafb5cb8471e54afdc9054d973535614f7675 authored by Linus Torvalds on 13 October 2019, 23:37:36 UTC
Linux 5.4-rc3
Linux 5.4-rc3
Tip revision: 4f5cafb
blk_types.h
/* 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/ktime.h>
struct bio_set;
struct bio;
struct bio_integrity_payload;
struct page;
struct block_device;
struct io_context;
struct cgroup_subsys_state;
typedef void (bio_end_io_t) (struct bio *);
/*
* Block error status values. See block/blk-core:blk_errors for the details.
* Alpha cannot write a byte atomically, so we need to use 32-bit value.
*/
#if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
typedef u32 __bitwise blk_status_t;
#else
typedef u8 __bitwise blk_status_t;
#endif
#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_NEXUS ((__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)
#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_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_NEXUS:
case BLK_STS_MEDIUM:
case BLK_STS_PROTECTION:
return false;
}
/* Anything else could be a path failure, so should be retried */
return true;
}
/*
* From most significant bit:
* 1 bit: reserved for other usage, see below
* 12 bits: original size of bio
* 51 bits: issue time of bio
*/
#define BIO_ISSUE_RES_BITS 1
#define BIO_ISSUE_SIZE_BITS 12
#define BIO_ISSUE_RES_SHIFT (64 - BIO_ISSUE_RES_BITS)
#define BIO_ISSUE_SIZE_SHIFT (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
#define BIO_ISSUE_TIME_MASK ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
#define BIO_ISSUE_SIZE_MASK \
(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
#define BIO_ISSUE_RES_MASK (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
/* Reserved bit for blk-throtl */
#define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
struct bio_issue {
u64 value;
};
static inline u64 __bio_issue_time(u64 time)
{
return time & BIO_ISSUE_TIME_MASK;
}
static inline u64 bio_issue_time(struct bio_issue *issue)
{
return __bio_issue_time(issue->value);
}
static inline sector_t bio_issue_size(struct bio_issue *issue)
{
return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
}
static inline void bio_issue_init(struct bio_issue *issue,
sector_t size)
{
size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
(ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
((u64)size << BIO_ISSUE_SIZE_SHIFT));
}
/*
* 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 gendisk *bi_disk;
unsigned int bi_opf; /* bottom bits req flags,
* top bits REQ_OP. Use
* accessors.
*/
unsigned short bi_flags; /* status, etc and bvec pool number */
unsigned short bi_ioprio;
unsigned short bi_write_hint;
blk_status_t bi_status;
u8 bi_partno;
struct bvec_iter bi_iter;
atomic_t __bi_remaining;
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;
struct bio_issue bi_issue;
#ifdef CONFIG_BLK_CGROUP_IOCOST
u64 bi_iocost_cost;
#endif
#endif
union {
#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()
*/
unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
atomic_t __bi_cnt; /* pin count */
struct bio_vec *bi_io_vec; /* the actual vec list */
struct bio_set *bi_pool;
/*
* We can inline a number of vecs at the end of the bio, to avoid
* double allocations for a small number of bio_vecs. This member
* MUST obviously be kept at the very end of the bio.
*/
struct bio_vec bi_inline_vecs[0];
};
#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
/*
* bio flags
*/
enum {
BIO_NO_PAGE_REF, /* don't put release vec pages */
BIO_CLONED, /* doesn't own data */
BIO_BOUNCED, /* bio is a bounce bio */
BIO_USER_MAPPED, /* contains user pages */
BIO_NULL_MAPPED, /* contains invalid user pages */
BIO_WORKINGSET, /* contains userspace workingset pages */
BIO_QUIET, /* Make BIO Quiet */
BIO_CHAIN, /* chained bio, ->bi_remaining in effect */
BIO_REFFED, /* bio has elevated ->bi_cnt */
BIO_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_QUEUE_ENTERED, /* can use blk_queue_enter_live() */
BIO_TRACKED, /* set if bio goes through the rq_qos path */
BIO_FLAG_LAST
};
/* See BVEC_POOL_OFFSET below before adding new flags */
/*
* We support 6 different bvec pools, the last one is magic in that it
* is backed by a mempool.
*/
#define BVEC_POOL_NR 6
#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
/*
* Top 3 bits of bio flags indicate the pool the bvecs came from. We add
* 1 to the actual index so that 0 indicates that there are no bvecs to be
* freed.
*/
#define BVEC_POOL_BITS (3)
#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
#if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
# error "BVEC_POOL_BITS is too small"
#endif
/*
* Flags starting here get preserved by bio_reset() - this includes
* only BVEC_POOL_IDX()
*/
#define BIO_RESET_BITS BVEC_POOL_OFFSET
typedef __u32 __bitwise blk_mq_req_flags_t;
/*
* Operations and flags 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.
*/
#define REQ_OP_BITS 8
#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
#define REQ_FLAG_BITS 24
enum req_opf {
/* read sectors from the device */
REQ_OP_READ = 0,
/* write sectors to the device */
REQ_OP_WRITE = 1,
/* flush the volatile write cache */
REQ_OP_FLUSH = 2,
/* discard sectors */
REQ_OP_DISCARD = 3,
/* securely erase sectors */
REQ_OP_SECURE_ERASE = 5,
/* reset a zone write pointer */
REQ_OP_ZONE_RESET = 6,
/* write the same sector many times */
REQ_OP_WRITE_SAME = 7,
/* reset all the zone present on the device */
REQ_OP_ZONE_RESET_ALL = 8,
/* write the zero filled sector many times */
REQ_OP_WRITE_ZEROES = 9,
/* SCSI passthrough using struct scsi_request */
REQ_OP_SCSI_IN = 32,
REQ_OP_SCSI_OUT = 33,
/* Driver private requests */
REQ_OP_DRV_IN = 34,
REQ_OP_DRV_OUT = 35,
REQ_OP_LAST,
};
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_NOWAIT_INLINE, /* Return would-block error inline */
/*
* When a shared kthread needs to issue a bio for a cgroup, doing
* so synchronously can lead to priority inversions as the kthread
* can be trapped waiting for that cgroup. CGROUP_PUNT flag makes
* submit_bio() punt the actual issuing to a dedicated per-blkcg
* work item to avoid such priority inversions.
*/
__REQ_CGROUP_PUNT,
/* command specific flags for REQ_OP_WRITE_ZEROES: */
__REQ_NOUNMAP, /* do not free blocks when zeroing */
__REQ_HIPRI,
/* for driver use */
__REQ_DRV,
__REQ_SWAP, /* swapping request. */
__REQ_NR_BITS, /* stops here */
};
#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
#define REQ_SYNC (1ULL << __REQ_SYNC)
#define REQ_META (1ULL << __REQ_META)
#define REQ_PRIO (1ULL << __REQ_PRIO)
#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
#define REQ_IDLE (1ULL << __REQ_IDLE)
#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
#define REQ_FUA (1ULL << __REQ_FUA)
#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
#define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
#define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
#define REQ_NOWAIT_INLINE (1ULL << __REQ_NOWAIT_INLINE)
#define REQ_CGROUP_PUNT (1ULL << __REQ_CGROUP_PUNT)
#define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
#define REQ_HIPRI (1ULL << __REQ_HIPRI)
#define REQ_DRV (1ULL << __REQ_DRV)
#define REQ_SWAP (1ULL << __REQ_SWAP)
#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,
NR_STAT_GROUPS
};
#define bio_op(bio) \
((bio)->bi_opf & REQ_OP_MASK)
#define req_op(req) \
((req)->cmd_flags & REQ_OP_MASK)
/* obsolete, don't use in new code */
static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
unsigned op_flags)
{
bio->bi_opf = op | op_flags;
}
static inline bool op_is_write(unsigned int op)
{
return (op & 1);
}
/*
* Check if the bio or request is one that needs special treatment in the
* flush state machine.
*/
static inline bool op_is_flush(unsigned int 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(unsigned int op)
{
return (op & REQ_OP_MASK) == REQ_OP_READ ||
(op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
}
static inline bool op_is_discard(unsigned int op)
{
return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
}
static inline int op_stat_group(unsigned int op)
{
if (op_is_discard(op))
return STAT_DISCARD;
return op_is_write(op);
}
typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE -1U
#define BLK_QC_T_EAGAIN -2U
#define BLK_QC_T_SHIFT 16
#define BLK_QC_T_INTERNAL (1U << 31)
static inline bool blk_qc_t_valid(blk_qc_t cookie)
{
return cookie != BLK_QC_T_NONE && cookie != BLK_QC_T_EAGAIN;
}
static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
{
return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
}
static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
{
return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
}
static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
{
return (cookie & BLK_QC_T_INTERNAL) != 0;
}
struct blk_rq_stat {
u64 mean;
u64 min;
u64 max;
u32 nr_samples;
u64 batch;
};
#endif /* __LINUX_BLK_TYPES_H */