1 /*
2 * Block data types and constants. Directly include this file only to
3 * break include dependency loop.
4 */
5 #ifndef __LINUX_BLK_TYPES_H
6 #define __LINUX_BLK_TYPES_H
7
8 #include <linux/types.h>
9 #include <linux/bvec.h>
10
11 struct bio_set;
12 struct bio;
13 struct bio_integrity_payload;
14 struct page;
15 struct block_device;
16 struct io_context;
17 struct cgroup_subsys_state;
18 typedef void (bio_end_io_t) (struct bio *);
19
20 #ifdef CONFIG_BLOCK
21 /*
22 * main unit of I/O for the block layer and lower layers (ie drivers and
23 * stacking drivers)
24 */
25 struct bio {
26 struct bio *bi_next; /* request queue link */
27 struct block_device *bi_bdev;
28 unsigned short bi_write_hint;
29 int bi_error;
30 unsigned int bi_opf; /* bottom bits req flags,
31 * top bits REQ_OP. Use
32 * accessors.
33 */
34 unsigned short bi_flags; /* status, command, etc */
35 unsigned short bi_ioprio;
36
37 struct bvec_iter bi_iter;
38
39 /* Number of segments in this BIO after
40 * physical address coalescing is performed.
41 */
42 unsigned int bi_phys_segments;
43
44 /*
45 * To keep track of the max segment size, we account for the
46 * sizes of the first and last mergeable segments in this bio.
47 */
48 unsigned int bi_seg_front_size;
49 unsigned int bi_seg_back_size;
50
51 atomic_t __bi_remaining;
52
53 bio_end_io_t *bi_end_io;
54
55 void *bi_private;
56 #ifdef CONFIG_BLK_CGROUP
57 /*
58 * Optional ioc and css associated with this bio. Put on bio
59 * release. Read comment on top of bio_associate_current().
60 */
61 struct io_context *bi_ioc;
62 struct cgroup_subsys_state *bi_css;
63 #endif
64 union {
65 #if defined(CONFIG_BLK_DEV_INTEGRITY)
66 struct bio_integrity_payload *bi_integrity; /* data integrity */
67 #endif
68 };
69
70 unsigned short bi_vcnt; /* how many bio_vec's */
71
72 /*
73 * Everything starting with bi_max_vecs will be preserved by bio_reset()
74 */
75
76 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
77
78 atomic_t __bi_cnt; /* pin count */
79
80 struct bio_vec *bi_io_vec; /* the actual vec list */
81
82 struct bio_set *bi_pool;
83
84 /*
85 * We can inline a number of vecs at the end of the bio, to avoid
86 * double allocations for a small number of bio_vecs. This member
87 * MUST obviously be kept at the very end of the bio.
88 */
89 struct bio_vec bi_inline_vecs[0];
90 };
91
92 #define BIO_OP_SHIFT (8 * FIELD_SIZEOF(struct bio, bi_opf) - REQ_OP_BITS)
93 #define bio_flags(bio) ((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1))
94 #define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT)
95
96 #define bio_set_op_attrs(bio, op, op_flags) do { \
97 if (__builtin_constant_p(op)) \
98 BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS)); \
99 else \
100 WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS)); \
101 if (__builtin_constant_p(op_flags)) \
102 BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \
103 else \
104 WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \
105 (bio)->bi_opf = bio_flags(bio); \
106 (bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT); \
107 (bio)->bi_opf |= (op_flags); \
108 } while (0)
109
110 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
111
112 /*
113 * bio flags
114 */
115 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
116 #define BIO_CLONED 2 /* doesn't own data */
117 #define BIO_BOUNCED 3 /* bio is a bounce bio */
118 #define BIO_USER_MAPPED 4 /* contains user pages */
119 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
120 #define BIO_QUIET 6 /* Make BIO Quiet */
121 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
122 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
123
124 /*
125 * Flags starting here get preserved by bio_reset() - this includes
126 * BVEC_POOL_IDX()
127 */
128 #define BIO_RESET_BITS 10
129
130 /*
131 * We support 6 different bvec pools, the last one is magic in that it
132 * is backed by a mempool.
133 */
134 #define BVEC_POOL_NR 6
135 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
136
137 /*
138 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add
139 * 1 to the actual index so that 0 indicates that there are no bvecs to be
140 * freed.
141 */
142 #define BVEC_POOL_BITS (4)
143 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
144 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
145
146 #endif /* CONFIG_BLOCK */
147
148 /*
149 * Request flags. For use in the cmd_flags field of struct request, and in
150 * bi_opf of struct bio. Note that some flags are only valid in either one.
151 */
152 enum rq_flag_bits {
153 /* common flags */
154 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
155 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
156 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
157
158 __REQ_SYNC, /* request is sync (sync write or read) */
159 __REQ_META, /* metadata io request */
160 __REQ_PRIO, /* boost priority in cfq */
161
162 __REQ_NOIDLE, /* don't anticipate more IO after this one */
163 __REQ_INTEGRITY, /* I/O includes block integrity payload */
164 __REQ_FUA, /* forced unit access */
165 __REQ_PREFLUSH, /* request for cache flush */
166
167 /* bio only flags */
168 __REQ_RAHEAD, /* read ahead, can fail anytime */
169 __REQ_THROTTLED, /* This bio has already been subjected to
170 * throttling rules. Don't do it again. */
171
172 /* request only flags */
173 __REQ_SORTED, /* elevator knows about this request */
174 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
175 __REQ_NOMERGE, /* don't touch this for merging */
176 __REQ_STARTED, /* drive already may have started this one */
177 __REQ_DONTPREP, /* don't call prep for this one */
178 __REQ_QUEUED, /* uses queueing */
179 __REQ_ELVPRIV, /* elevator private data attached */
180 __REQ_FAILED, /* set if the request failed */
181 __REQ_QUIET, /* don't worry about errors */
182 __REQ_PREEMPT, /* set for "ide_preempt" requests and also
183 for requests for which the SCSI "quiesce"
184 state must be ignored. */
185 __REQ_ALLOCED, /* request came from our alloc pool */
186 __REQ_COPY_USER, /* contains copies of user pages */
187 __REQ_FLUSH_SEQ, /* request for flush sequence */
188 __REQ_IO_STAT, /* account I/O stat */
189 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
190 __REQ_PM, /* runtime pm request */
191 __REQ_HASHED, /* on IO scheduler merge hash */
192 __REQ_MQ_INFLIGHT, /* track inflight for MQ */
193 __REQ_NR_BITS, /* stops here */
194 };
195
196 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
197 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
198 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
199 #define REQ_SYNC (1ULL << __REQ_SYNC)
200 #define REQ_META (1ULL << __REQ_META)
201 #define REQ_PRIO (1ULL << __REQ_PRIO)
202 #define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
203 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
204
205 #define REQ_FAILFAST_MASK \
206 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
207 #define REQ_COMMON_MASK \
208 (REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \
209 REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE)
210 #define REQ_CLONE_MASK REQ_COMMON_MASK
211
212 /* This mask is used for both bio and request merge checking */
213 #define REQ_NOMERGE_FLAGS \
214 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_PREFLUSH | REQ_FUA | REQ_FLUSH_SEQ)
215
216 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
217 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
218
219 #define REQ_SORTED (1ULL << __REQ_SORTED)
220 #define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
221 #define REQ_FUA (1ULL << __REQ_FUA)
222 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
223 #define REQ_STARTED (1ULL << __REQ_STARTED)
224 #define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
225 #define REQ_QUEUED (1ULL << __REQ_QUEUED)
226 #define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
227 #define REQ_FAILED (1ULL << __REQ_FAILED)
228 #define REQ_QUIET (1ULL << __REQ_QUIET)
229 #define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
230 #define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
231 #define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
232 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
233 #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
234 #define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
235 #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
236 #define REQ_PM (1ULL << __REQ_PM)
237 #define REQ_HASHED (1ULL << __REQ_HASHED)
238 #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)
239
240 enum req_op {
241 REQ_OP_READ,
242 REQ_OP_WRITE,
243 REQ_OP_DISCARD, /* request to discard sectors */
244 REQ_OP_SECURE_ERASE, /* request to securely erase sectors */
245 REQ_OP_WRITE_SAME, /* write same block many times */
246 REQ_OP_FLUSH, /* request for cache flush */
247 };
248
249 #define REQ_OP_BITS 3
250
251 typedef unsigned int blk_qc_t;
252 #define BLK_QC_T_NONE -1U
253 #define BLK_QC_T_SHIFT 16
254
blk_qc_t_valid(blk_qc_t cookie)255 static inline bool blk_qc_t_valid(blk_qc_t cookie)
256 {
257 return cookie != BLK_QC_T_NONE;
258 }
259
blk_tag_to_qc_t(unsigned int tag,unsigned int queue_num)260 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
261 {
262 return tag | (queue_num << BLK_QC_T_SHIFT);
263 }
264
blk_qc_t_to_queue_num(blk_qc_t cookie)265 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
266 {
267 return cookie >> BLK_QC_T_SHIFT;
268 }
269
blk_qc_t_to_tag(blk_qc_t cookie)270 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
271 {
272 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
273 }
274
275 #endif /* __LINUX_BLK_TYPES_H */
276