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 /* hack for device mapper, don't use elsewhere: */
37 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
39 struct blk_issue_stat {
44 * main unit of I/O for the block layer and lower layers (ie drivers and
48 struct bio *bi_next; /* request queue link */
49 struct block_device *bi_bdev;
50 blk_status_t bi_status;
51 unsigned int bi_opf; /* bottom bits req flags,
52 * top bits REQ_OP. Use
55 unsigned short bi_flags; /* status, etc and bvec pool number */
56 unsigned short bi_ioprio;
58 struct bvec_iter bi_iter;
60 /* Number of segments in this BIO after
61 * physical address coalescing is performed.
63 unsigned int bi_phys_segments;
66 * To keep track of the max segment size, we account for the
67 * sizes of the first and last mergeable segments in this bio.
69 unsigned int bi_seg_front_size;
70 unsigned int bi_seg_back_size;
72 atomic_t __bi_remaining;
74 bio_end_io_t *bi_end_io;
77 #ifdef CONFIG_BLK_CGROUP
79 * Optional ioc and css associated with this bio. Put on bio
80 * release. Read comment on top of bio_associate_current().
82 struct io_context *bi_ioc;
83 struct cgroup_subsys_state *bi_css;
84 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
86 struct blk_issue_stat bi_issue_stat;
90 #if defined(CONFIG_BLK_DEV_INTEGRITY)
91 struct bio_integrity_payload *bi_integrity; /* data integrity */
95 unsigned short bi_vcnt; /* how many bio_vec's */
98 * Everything starting with bi_max_vecs will be preserved by bio_reset()
101 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
103 atomic_t __bi_cnt; /* pin count */
105 struct bio_vec *bi_io_vec; /* the actual vec list */
107 struct bio_set *bi_pool;
110 * We can inline a number of vecs at the end of the bio, to avoid
111 * double allocations for a small number of bio_vecs. This member
112 * MUST obviously be kept at the very end of the bio.
114 struct bio_vec bi_inline_vecs[0];
117 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
122 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
123 #define BIO_CLONED 2 /* doesn't own data */
124 #define BIO_BOUNCED 3 /* bio is a bounce bio */
125 #define BIO_USER_MAPPED 4 /* contains user pages */
126 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
127 #define BIO_QUIET 6 /* Make BIO Quiet */
128 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
129 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
130 #define BIO_THROTTLED 9 /* This bio has already been subjected to
131 * throttling rules. Don't do it again. */
132 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
134 /* See BVEC_POOL_OFFSET below before adding new flags */
137 * We support 6 different bvec pools, the last one is magic in that it
138 * is backed by a mempool.
140 #define BVEC_POOL_NR 6
141 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
144 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
145 * 1 to the actual index so that 0 indicates that there are no bvecs to be
148 #define BVEC_POOL_BITS (3)
149 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
150 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
151 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
152 # error "BVEC_POOL_BITS is too small"
156 * Flags starting here get preserved by bio_reset() - this includes
157 * only BVEC_POOL_IDX()
159 #define BIO_RESET_BITS BVEC_POOL_OFFSET
162 * Operations and flags common to the bio and request structures.
163 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
165 * The least significant bit of the operation number indicates the data
166 * transfer direction:
168 * - if the least significant bit is set transfers are TO the device
169 * - if the least significant bit is not set transfers are FROM the device
171 * If a operation does not transfer data the least significant bit has no
174 #define REQ_OP_BITS 8
175 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
176 #define REQ_FLAG_BITS 24
179 /* read sectors from the device */
181 /* write sectors to the device */
183 /* flush the volatile write cache */
185 /* discard sectors */
187 /* get zone information */
188 REQ_OP_ZONE_REPORT = 4,
189 /* securely erase sectors */
190 REQ_OP_SECURE_ERASE = 5,
191 /* seset a zone write pointer */
192 REQ_OP_ZONE_RESET = 6,
193 /* write the same sector many times */
194 REQ_OP_WRITE_SAME = 7,
195 /* write the zero filled sector many times */
196 REQ_OP_WRITE_ZEROES = 9,
198 /* SCSI passthrough using struct scsi_request */
200 REQ_OP_SCSI_OUT = 33,
201 /* Driver private requests */
209 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
211 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
212 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
213 __REQ_SYNC, /* request is sync (sync write or read) */
214 __REQ_META, /* metadata io request */
215 __REQ_PRIO, /* boost priority in cfq */
216 __REQ_NOMERGE, /* don't touch this for merging */
217 __REQ_IDLE, /* anticipate more IO after this one */
218 __REQ_INTEGRITY, /* I/O includes block integrity payload */
219 __REQ_FUA, /* forced unit access */
220 __REQ_PREFLUSH, /* request for cache flush */
221 __REQ_RAHEAD, /* read ahead, can fail anytime */
222 __REQ_BACKGROUND, /* background IO */
224 /* command specific flags for REQ_OP_WRITE_ZEROES: */
225 __REQ_NOUNMAP, /* do not free blocks when zeroing */
227 __REQ_NR_BITS, /* stops here */
230 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
231 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
232 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
233 #define REQ_SYNC (1ULL << __REQ_SYNC)
234 #define REQ_META (1ULL << __REQ_META)
235 #define REQ_PRIO (1ULL << __REQ_PRIO)
236 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
237 #define REQ_IDLE (1ULL << __REQ_IDLE)
238 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
239 #define REQ_FUA (1ULL << __REQ_FUA)
240 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
241 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
242 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
244 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
246 #define REQ_FAILFAST_MASK \
247 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
249 #define REQ_NOMERGE_FLAGS \
250 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
252 #define bio_op(bio) \
253 ((bio)->bi_opf & REQ_OP_MASK)
254 #define req_op(req) \
255 ((req)->cmd_flags & REQ_OP_MASK)
257 /* obsolete, don't use in new code */
258 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
261 bio->bi_opf = op | op_flags;
264 static inline bool op_is_write(unsigned int op)
270 * Check if the bio or request is one that needs special treatment in the
271 * flush state machine.
273 static inline bool op_is_flush(unsigned int op)
275 return op & (REQ_FUA | REQ_PREFLUSH);
279 * Reads are always treated as synchronous, as are requests with the FUA or
280 * PREFLUSH flag. Other operations may be marked as synchronous using the
283 static inline bool op_is_sync(unsigned int op)
285 return (op & REQ_OP_MASK) == REQ_OP_READ ||
286 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
289 typedef unsigned int blk_qc_t;
290 #define BLK_QC_T_NONE -1U
291 #define BLK_QC_T_SHIFT 16
292 #define BLK_QC_T_INTERNAL (1U << 31)
294 static inline bool blk_qc_t_valid(blk_qc_t cookie)
296 return cookie != BLK_QC_T_NONE;
299 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
302 blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
305 ret |= BLK_QC_T_INTERNAL;
310 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
312 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
315 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
317 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
320 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
322 return (cookie & BLK_QC_T_INTERNAL) != 0;
334 #endif /* __LINUX_BLK_TYPES_H */