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 * Block error status values. See block/blk-core:blk_errors for the details.
23 typedef u8 __bitwise blk_status_t;
25 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
26 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
27 #define BLK_STS_NOSPC ((__force blk_status_t)3)
28 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
29 #define BLK_STS_TARGET ((__force blk_status_t)5)
30 #define BLK_STS_NEXUS ((__force blk_status_t)6)
31 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
32 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
33 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
34 #define BLK_STS_IOERR ((__force blk_status_t)10)
36 struct blk_issue_stat {
41 * main unit of I/O for the block layer and lower layers (ie drivers and
45 struct bio *bi_next; /* request queue link */
46 struct block_device *bi_bdev;
48 unsigned int bi_opf; /* bottom bits req flags,
49 * top bits REQ_OP. Use
52 unsigned short bi_flags; /* status, etc and bvec pool number */
53 unsigned short bi_ioprio;
55 struct bvec_iter bi_iter;
57 /* Number of segments in this BIO after
58 * physical address coalescing is performed.
60 unsigned int bi_phys_segments;
63 * To keep track of the max segment size, we account for the
64 * sizes of the first and last mergeable segments in this bio.
66 unsigned int bi_seg_front_size;
67 unsigned int bi_seg_back_size;
69 atomic_t __bi_remaining;
71 bio_end_io_t *bi_end_io;
74 #ifdef CONFIG_BLK_CGROUP
76 * Optional ioc and css associated with this bio. Put on bio
77 * release. Read comment on top of bio_associate_current().
79 struct io_context *bi_ioc;
80 struct cgroup_subsys_state *bi_css;
81 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
83 struct blk_issue_stat bi_issue_stat;
87 #if defined(CONFIG_BLK_DEV_INTEGRITY)
88 struct bio_integrity_payload *bi_integrity; /* data integrity */
92 unsigned short bi_vcnt; /* how many bio_vec's */
95 * Everything starting with bi_max_vecs will be preserved by bio_reset()
98 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
100 atomic_t __bi_cnt; /* pin count */
102 struct bio_vec *bi_io_vec; /* the actual vec list */
104 struct bio_set *bi_pool;
107 * We can inline a number of vecs at the end of the bio, to avoid
108 * double allocations for a small number of bio_vecs. This member
109 * MUST obviously be kept at the very end of the bio.
111 struct bio_vec bi_inline_vecs[0];
114 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
119 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
120 #define BIO_CLONED 2 /* doesn't own data */
121 #define BIO_BOUNCED 3 /* bio is a bounce bio */
122 #define BIO_USER_MAPPED 4 /* contains user pages */
123 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
124 #define BIO_QUIET 6 /* Make BIO Quiet */
125 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
126 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
127 #define BIO_THROTTLED 9 /* This bio has already been subjected to
128 * throttling rules. Don't do it again. */
129 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
131 /* See BVEC_POOL_OFFSET below before adding new flags */
134 * We support 6 different bvec pools, the last one is magic in that it
135 * is backed by a mempool.
137 #define BVEC_POOL_NR 6
138 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
141 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
142 * 1 to the actual index so that 0 indicates that there are no bvecs to be
145 #define BVEC_POOL_BITS (3)
146 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
147 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
148 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
149 # error "BVEC_POOL_BITS is too small"
153 * Flags starting here get preserved by bio_reset() - this includes
154 * only BVEC_POOL_IDX()
156 #define BIO_RESET_BITS BVEC_POOL_OFFSET
159 * Operations and flags common to the bio and request structures.
160 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
162 * The least significant bit of the operation number indicates the data
163 * transfer direction:
165 * - if the least significant bit is set transfers are TO the device
166 * - if the least significant bit is not set transfers are FROM the device
168 * If a operation does not transfer data the least significant bit has no
171 #define REQ_OP_BITS 8
172 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
173 #define REQ_FLAG_BITS 24
176 /* read sectors from the device */
178 /* write sectors to the device */
180 /* flush the volatile write cache */
182 /* discard sectors */
184 /* get zone information */
185 REQ_OP_ZONE_REPORT = 4,
186 /* securely erase sectors */
187 REQ_OP_SECURE_ERASE = 5,
188 /* seset a zone write pointer */
189 REQ_OP_ZONE_RESET = 6,
190 /* write the same sector many times */
191 REQ_OP_WRITE_SAME = 7,
192 /* write the zero filled sector many times */
193 REQ_OP_WRITE_ZEROES = 9,
195 /* SCSI passthrough using struct scsi_request */
197 REQ_OP_SCSI_OUT = 33,
198 /* Driver private requests */
206 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
208 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
209 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
210 __REQ_SYNC, /* request is sync (sync write or read) */
211 __REQ_META, /* metadata io request */
212 __REQ_PRIO, /* boost priority in cfq */
213 __REQ_NOMERGE, /* don't touch this for merging */
214 __REQ_IDLE, /* anticipate more IO after this one */
215 __REQ_INTEGRITY, /* I/O includes block integrity payload */
216 __REQ_FUA, /* forced unit access */
217 __REQ_PREFLUSH, /* request for cache flush */
218 __REQ_RAHEAD, /* read ahead, can fail anytime */
219 __REQ_BACKGROUND, /* background IO */
221 /* command specific flags for REQ_OP_WRITE_ZEROES: */
222 __REQ_NOUNMAP, /* do not free blocks when zeroing */
224 __REQ_NR_BITS, /* stops here */
227 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
228 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
229 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
230 #define REQ_SYNC (1ULL << __REQ_SYNC)
231 #define REQ_META (1ULL << __REQ_META)
232 #define REQ_PRIO (1ULL << __REQ_PRIO)
233 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
234 #define REQ_IDLE (1ULL << __REQ_IDLE)
235 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
236 #define REQ_FUA (1ULL << __REQ_FUA)
237 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
238 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
239 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
241 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
243 #define REQ_FAILFAST_MASK \
244 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
246 #define REQ_NOMERGE_FLAGS \
247 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
249 #define bio_op(bio) \
250 ((bio)->bi_opf & REQ_OP_MASK)
251 #define req_op(req) \
252 ((req)->cmd_flags & REQ_OP_MASK)
254 /* obsolete, don't use in new code */
255 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
258 bio->bi_opf = op | op_flags;
261 static inline bool op_is_write(unsigned int op)
267 * Check if the bio or request is one that needs special treatment in the
268 * flush state machine.
270 static inline bool op_is_flush(unsigned int op)
272 return op & (REQ_FUA | REQ_PREFLUSH);
276 * Reads are always treated as synchronous, as are requests with the FUA or
277 * PREFLUSH flag. Other operations may be marked as synchronous using the
280 static inline bool op_is_sync(unsigned int op)
282 return (op & REQ_OP_MASK) == REQ_OP_READ ||
283 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
286 typedef unsigned int blk_qc_t;
287 #define BLK_QC_T_NONE -1U
288 #define BLK_QC_T_SHIFT 16
289 #define BLK_QC_T_INTERNAL (1U << 31)
291 static inline bool blk_qc_t_valid(blk_qc_t cookie)
293 return cookie != BLK_QC_T_NONE;
296 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
299 blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
302 ret |= BLK_QC_T_INTERNAL;
307 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
309 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
312 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
314 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
317 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
319 return (cookie & BLK_QC_T_INTERNAL) != 0;
331 #endif /* __LINUX_BLK_TYPES_H */