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
10 struct bio_set;
11 struct bio;
12 struct bio_integrity_payload;
13 struct page;
14 struct block_device;
15 struct io_context;
16 struct cgroup_subsys_state;
17 typedef void (bio_end_io_t) (struct bio *);
18 typedef void (bio_destructor_t) (struct bio *);
19
20 /*
21 * was unsigned short, but we might as well be ready for > 64kB I/O pages
22 */
23 struct bio_vec {
24 struct page *bv_page;
25 unsigned int bv_len;
26 unsigned int bv_offset;
27 };
28
29 #ifdef CONFIG_BLOCK
30
31 struct bvec_iter {
32 sector_t bi_sector; /* device address in 512 byte
33 sectors */
34 unsigned int bi_size; /* residual I/O count */
35
36 unsigned int bi_idx; /* current index into bvl_vec */
37
38 unsigned int bi_bvec_done; /* number of bytes completed in
39 current bvec */
40 };
41
42 /*
43 * main unit of I/O for the block layer and lower layers (ie drivers and
44 * stacking drivers)
45 */
46 struct bio {
47 struct bio *bi_next; /* request queue link */
48 struct block_device *bi_bdev;
49 unsigned int bi_flags; /* status, command, etc */
50 int bi_error;
51 unsigned long bi_rw; /* bottom bits READ/WRITE,
52 * top bits priority
53 */
54
55 struct bvec_iter bi_iter;
56
57 /* Number of segments in this BIO after
58 * physical address coalescing is performed.
59 */
60 unsigned int bi_phys_segments;
61
62 /*
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.
65 */
66 unsigned int bi_seg_front_size;
67 unsigned int bi_seg_back_size;
68
69 atomic_t __bi_remaining;
70
71 bio_end_io_t *bi_end_io;
72
73 void *bi_private;
74 #ifdef CONFIG_BLK_CGROUP
75 /*
76 * Optional ioc and css associated with this bio. Put on bio
77 * release. Read comment on top of bio_associate_current().
78 */
79 struct io_context *bi_ioc;
80 struct cgroup_subsys_state *bi_css;
81 #endif
82 union {
83 #if defined(CONFIG_BLK_DEV_INTEGRITY)
84 struct bio_integrity_payload *bi_integrity; /* data integrity */
85 #endif
86 };
87
88 unsigned short bi_vcnt; /* how many bio_vec's */
89
90 /*
91 * Everything starting with bi_max_vecs will be preserved by bio_reset()
92 */
93
94 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
95
96 atomic_t __bi_cnt; /* pin count */
97
98 struct bio_vec *bi_io_vec; /* the actual vec list */
99
100 struct bio_set *bi_pool;
101
102 /*
103 * We can inline a number of vecs at the end of the bio, to avoid
104 * double allocations for a small number of bio_vecs. This member
105 * MUST obviously be kept at the very end of the bio.
106 */
107 struct bio_vec bi_inline_vecs[0];
108 };
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 * BIO_POOL_IDX()
127 */
128 #define BIO_RESET_BITS 13
129 #define BIO_OWNS_VEC 13 /* bio_free() should free bvec */
130
131 /*
132 * top 4 bits of bio flags indicate the pool this bio came from
133 */
134 #define BIO_POOL_BITS (4)
135 #define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
136 #define BIO_POOL_OFFSET (32 - BIO_POOL_BITS)
137 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
138 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
139
140 #endif /* CONFIG_BLOCK */
141
142 /*
143 * Request flags. For use in the cmd_flags field of struct request, and in
144 * bi_rw of struct bio. Note that some flags are only valid in either one.
145 */
146 enum rq_flag_bits {
147 /* common flags */
148 __REQ_WRITE, /* not set, read. set, write */
149 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
150 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
151 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
152
153 __REQ_SYNC, /* request is sync (sync write or read) */
154 __REQ_META, /* metadata io request */
155 __REQ_PRIO, /* boost priority in cfq */
156 __REQ_DISCARD, /* request to discard sectors */
157 __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */
158 __REQ_WRITE_SAME, /* write same block many times */
159
160 __REQ_NOIDLE, /* don't anticipate more IO after this one */
161 __REQ_INTEGRITY, /* I/O includes block integrity payload */
162 __REQ_FUA, /* forced unit access */
163 __REQ_FLUSH, /* request for cache flush */
164
165 /* bio only flags */
166 __REQ_RAHEAD, /* read ahead, can fail anytime */
167 __REQ_THROTTLED, /* This bio has already been subjected to
168 * throttling rules. Don't do it again. */
169
170 /* request only flags */
171 __REQ_SORTED, /* elevator knows about this request */
172 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
173 __REQ_NOMERGE, /* don't touch this for merging */
174 __REQ_STARTED, /* drive already may have started this one */
175 __REQ_DONTPREP, /* don't call prep for this one */
176 __REQ_QUEUED, /* uses queueing */
177 __REQ_ELVPRIV, /* elevator private data attached */
178 __REQ_FAILED, /* set if the request failed */
179 __REQ_QUIET, /* don't worry about errors */
180 __REQ_PREEMPT, /* set for "ide_preempt" requests and also
181 for requests for which the SCSI "quiesce"
182 state must be ignored. */
183 __REQ_ALLOCED, /* request came from our alloc pool */
184 __REQ_COPY_USER, /* contains copies of user pages */
185 __REQ_FLUSH_SEQ, /* request for flush sequence */
186 __REQ_IO_STAT, /* account I/O stat */
187 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
188 __REQ_PM, /* runtime pm request */
189 __REQ_HASHED, /* on IO scheduler merge hash */
190 __REQ_MQ_INFLIGHT, /* track inflight for MQ */
191 __REQ_NR_BITS, /* stops here */
192 };
193
194 #define REQ_WRITE (1ULL << __REQ_WRITE)
195 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
196 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
197 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
198 #define REQ_SYNC (1ULL << __REQ_SYNC)
199 #define REQ_META (1ULL << __REQ_META)
200 #define REQ_PRIO (1ULL << __REQ_PRIO)
201 #define REQ_DISCARD (1ULL << __REQ_DISCARD)
202 #define REQ_WRITE_SAME (1ULL << __REQ_WRITE_SAME)
203 #define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
204 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
205
206 #define REQ_FAILFAST_MASK \
207 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
208 #define REQ_COMMON_MASK \
209 (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
210 REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \
211 REQ_SECURE | REQ_INTEGRITY | REQ_NOMERGE)
212 #define REQ_CLONE_MASK REQ_COMMON_MASK
213
214 #define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME)
215
216 /* This mask is used for both bio and request merge checking */
217 #define REQ_NOMERGE_FLAGS \
218 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_FLUSH_SEQ)
219
220 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
221 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
222
223 #define REQ_SORTED (1ULL << __REQ_SORTED)
224 #define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
225 #define REQ_FUA (1ULL << __REQ_FUA)
226 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
227 #define REQ_STARTED (1ULL << __REQ_STARTED)
228 #define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
229 #define REQ_QUEUED (1ULL << __REQ_QUEUED)
230 #define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
231 #define REQ_FAILED (1ULL << __REQ_FAILED)
232 #define REQ_QUIET (1ULL << __REQ_QUIET)
233 #define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
234 #define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
235 #define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
236 #define REQ_FLUSH (1ULL << __REQ_FLUSH)
237 #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
238 #define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
239 #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
240 #define REQ_SECURE (1ULL << __REQ_SECURE)
241 #define REQ_PM (1ULL << __REQ_PM)
242 #define REQ_HASHED (1ULL << __REQ_HASHED)
243 #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)
244
245 typedef unsigned int blk_qc_t;
246 #define BLK_QC_T_NONE -1U
247 #define BLK_QC_T_SHIFT 16
248
249 static inline bool blk_qc_t_valid(blk_qc_t cookie)
250 {
251 return cookie != BLK_QC_T_NONE;
252 }
253
254 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
255 {
256 return tag | (queue_num << BLK_QC_T_SHIFT);
257 }
258
259 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
260 {
261 return cookie >> BLK_QC_T_SHIFT;
262 }
263
264 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
265 {
266 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
267 }
268
269 #endif /* __LINUX_BLK_TYPES_H */
270
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