2 * Block data types and constants. Directly include this file only to
3 * break include dependency loop.
5 #ifndef __LINUX_BLK_TYPES_H
6 #define __LINUX_BLK_TYPES_H
8 #include <linux/types.h>
9 #include <linux/bvec.h>
13 struct bio_integrity_payload;
17 struct cgroup_subsys_state;
18 typedef void (bio_end_io_t) (struct bio *);
21 * main unit of I/O for the block layer and lower layers (ie drivers and
25 struct bio *bi_next; /* request queue link */
26 struct block_device *bi_bdev;
28 unsigned int bi_opf; /* bottom bits req flags,
29 * top bits REQ_OP. Use
32 unsigned short bi_flags; /* status, command, etc */
33 unsigned short bi_ioprio;
35 struct bvec_iter bi_iter;
37 /* Number of segments in this BIO after
38 * physical address coalescing is performed.
40 unsigned int bi_phys_segments;
43 * To keep track of the max segment size, we account for the
44 * sizes of the first and last mergeable segments in this bio.
46 unsigned int bi_seg_front_size;
47 unsigned int bi_seg_back_size;
49 atomic_t __bi_remaining;
51 bio_end_io_t *bi_end_io;
54 #ifdef CONFIG_BLK_CGROUP
56 * Optional ioc and css associated with this bio. Put on bio
57 * release. Read comment on top of bio_associate_current().
59 struct io_context *bi_ioc;
60 struct cgroup_subsys_state *bi_css;
63 #if defined(CONFIG_BLK_DEV_INTEGRITY)
64 struct bio_integrity_payload *bi_integrity; /* data integrity */
68 unsigned short bi_vcnt; /* how many bio_vec's */
71 * Everything starting with bi_max_vecs will be preserved by bio_reset()
74 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
76 atomic_t __bi_cnt; /* pin count */
78 struct bio_vec *bi_io_vec; /* the actual vec list */
80 struct bio_set *bi_pool;
83 * We can inline a number of vecs at the end of the bio, to avoid
84 * double allocations for a small number of bio_vecs. This member
85 * MUST obviously be kept at the very end of the bio.
87 struct bio_vec bi_inline_vecs[0];
90 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
95 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
96 #define BIO_CLONED 2 /* doesn't own data */
97 #define BIO_BOUNCED 3 /* bio is a bounce bio */
98 #define BIO_USER_MAPPED 4 /* contains user pages */
99 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
100 #define BIO_QUIET 6 /* Make BIO Quiet */
101 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
102 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
103 #define BIO_THROTTLED 9 /* This bio has already been subjected to
104 * throttling rules. Don't do it again. */
107 * Flags starting here get preserved by bio_reset() - this includes
110 #define BIO_RESET_BITS 10
113 * We support 6 different bvec pools, the last one is magic in that it
114 * is backed by a mempool.
116 #define BVEC_POOL_NR 6
117 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
120 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add
121 * 1 to the actual index so that 0 indicates that there are no bvecs to be
124 #define BVEC_POOL_BITS (4)
125 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
126 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
129 * Operations and flags common to the bio and request structures.
130 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
132 * The least significant bit of the operation number indicates the data
133 * transfer direction:
135 * - if the least significant bit is set transfers are TO the device
136 * - if the least significant bit is not set transfers are FROM the device
138 * If a operation does not transfer data the least significant bit has no
141 #define REQ_OP_BITS 8
142 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
143 #define REQ_FLAG_BITS 24
146 /* read sectors from the device */
148 /* write sectors to the device */
150 /* flush the volatile write cache */
152 /* discard sectors */
154 /* get zone information */
155 REQ_OP_ZONE_REPORT = 4,
156 /* securely erase sectors */
157 REQ_OP_SECURE_ERASE = 5,
158 /* seset a zone write pointer */
159 REQ_OP_ZONE_RESET = 6,
160 /* write the same sector many times */
161 REQ_OP_WRITE_SAME = 7,
162 /* write the zero filled sector many times */
163 REQ_OP_WRITE_ZEROES = 8,
165 /* SCSI passthrough using struct scsi_request */
167 REQ_OP_SCSI_OUT = 33,
168 /* Driver private requests */
176 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
178 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
179 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
180 __REQ_SYNC, /* request is sync (sync write or read) */
181 __REQ_META, /* metadata io request */
182 __REQ_PRIO, /* boost priority in cfq */
183 __REQ_NOMERGE, /* don't touch this for merging */
184 __REQ_IDLE, /* anticipate more IO after this one */
185 __REQ_INTEGRITY, /* I/O includes block integrity payload */
186 __REQ_FUA, /* forced unit access */
187 __REQ_PREFLUSH, /* request for cache flush */
188 __REQ_RAHEAD, /* read ahead, can fail anytime */
189 __REQ_BACKGROUND, /* background IO */
190 __REQ_NR_BITS, /* stops here */
193 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
194 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
195 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
196 #define REQ_SYNC (1ULL << __REQ_SYNC)
197 #define REQ_META (1ULL << __REQ_META)
198 #define REQ_PRIO (1ULL << __REQ_PRIO)
199 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
200 #define REQ_IDLE (1ULL << __REQ_IDLE)
201 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
202 #define REQ_FUA (1ULL << __REQ_FUA)
203 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
204 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
205 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
207 #define REQ_FAILFAST_MASK \
208 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
210 #define REQ_NOMERGE_FLAGS \
211 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
213 #define bio_op(bio) \
214 ((bio)->bi_opf & REQ_OP_MASK)
215 #define req_op(req) \
216 ((req)->cmd_flags & REQ_OP_MASK)
218 /* obsolete, don't use in new code */
219 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
222 bio->bi_opf = op | op_flags;
225 static inline bool op_is_write(unsigned int op)
231 * Check if the bio or request is one that needs special treatment in the
232 * flush state machine.
234 static inline bool op_is_flush(unsigned int op)
236 return op & (REQ_FUA | REQ_PREFLUSH);
240 * Reads are always treated as synchronous, as are requests with the FUA or
241 * PREFLUSH flag. Other operations may be marked as synchronous using the
244 static inline bool op_is_sync(unsigned int op)
246 return (op & REQ_OP_MASK) == REQ_OP_READ ||
247 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
250 typedef unsigned int blk_qc_t;
251 #define BLK_QC_T_NONE -1U
252 #define BLK_QC_T_SHIFT 16
253 #define BLK_QC_T_INTERNAL (1U << 31)
255 static inline bool blk_qc_t_valid(blk_qc_t cookie)
257 return cookie != BLK_QC_T_NONE;
260 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
263 blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
266 ret |= BLK_QC_T_INTERNAL;
271 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
273 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
276 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
278 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
281 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
283 return (cookie & BLK_QC_T_INTERNAL) != 0;
286 struct blk_issue_stat {
290 #define BLK_RQ_STAT_BATCH 64
302 #endif /* __LINUX_BLK_TYPES_H */