Linux kernel mirror (for testing)
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linux
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#ifdef CONFIG_BLOCK
9
10#include <linux/types.h>
11
12struct bio_set;
13struct bio;
14struct bio_integrity_payload;
15struct page;
16struct block_device;
17struct io_context;
18struct cgroup_subsys_state;
19typedef void (bio_end_io_t) (struct bio *, int);
20typedef void (bio_destructor_t) (struct bio *);
21
22/*
23 * was unsigned short, but we might as well be ready for > 64kB I/O pages
24 */
25struct bio_vec {
26 struct page *bv_page;
27 unsigned int bv_len;
28 unsigned int bv_offset;
29};
30
31struct 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 */
46struct bio {
47 struct bio *bi_next; /* request queue link */
48 struct block_device *bi_bdev;
49 unsigned long bi_flags; /* status, command, etc */
50 unsigned long bi_rw; /* bottom bits READ/WRITE,
51 * top bits priority
52 */
53
54 struct bvec_iter bi_iter;
55
56 /* Number of segments in this BIO after
57 * physical address coalescing is performed.
58 */
59 unsigned int bi_phys_segments;
60
61 /*
62 * To keep track of the max segment size, we account for the
63 * sizes of the first and last mergeable segments in this bio.
64 */
65 unsigned int bi_seg_front_size;
66 unsigned int bi_seg_back_size;
67
68 atomic_t bi_remaining;
69
70 bio_end_io_t *bi_end_io;
71
72 void *bi_private;
73#ifdef CONFIG_BLK_CGROUP
74 /*
75 * Optional ioc and css associated with this bio. Put on bio
76 * release. Read comment on top of bio_associate_current().
77 */
78 struct io_context *bi_ioc;
79 struct cgroup_subsys_state *bi_css;
80#endif
81#if defined(CONFIG_BLK_DEV_INTEGRITY)
82 struct bio_integrity_payload *bi_integrity; /* data integrity */
83#endif
84
85 unsigned short bi_vcnt; /* how many bio_vec's */
86
87 /*
88 * Everything starting with bi_max_vecs will be preserved by bio_reset()
89 */
90
91 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
92
93 atomic_t bi_cnt; /* pin count */
94
95 struct bio_vec *bi_io_vec; /* the actual vec list */
96
97 struct bio_set *bi_pool;
98
99 /*
100 * We can inline a number of vecs at the end of the bio, to avoid
101 * double allocations for a small number of bio_vecs. This member
102 * MUST obviously be kept at the very end of the bio.
103 */
104 struct bio_vec bi_inline_vecs[0];
105};
106
107#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
108
109/*
110 * bio flags
111 */
112#define BIO_UPTODATE 0 /* ok after I/O completion */
113#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
114#define BIO_EOF 2 /* out-out-bounds error */
115#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
116#define BIO_CLONED 4 /* doesn't own data */
117#define BIO_BOUNCED 5 /* bio is a bounce bio */
118#define BIO_USER_MAPPED 6 /* contains user pages */
119#define BIO_EOPNOTSUPP 7 /* not supported */
120#define BIO_NULL_MAPPED 8 /* contains invalid user pages */
121#define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */
122#define BIO_QUIET 10 /* Make BIO Quiet */
123#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */
124#define BIO_SNAP_STABLE 12 /* bio data must be snapshotted during write */
125
126/*
127 * Flags starting here get preserved by bio_reset() - this includes
128 * BIO_POOL_IDX()
129 */
130#define BIO_RESET_BITS 13
131#define BIO_OWNS_VEC 13 /* bio_free() should free bvec */
132
133#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
134
135/*
136 * top 4 bits of bio flags indicate the pool this bio came from
137 */
138#define BIO_POOL_BITS (4)
139#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
140#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
141#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
142#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
143
144#endif /* CONFIG_BLOCK */
145
146/*
147 * Request flags. For use in the cmd_flags field of struct request, and in
148 * bi_rw of struct bio. Note that some flags are only valid in either one.
149 */
150enum rq_flag_bits {
151 /* common flags */
152 __REQ_WRITE, /* not set, read. set, write */
153 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
154 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
155 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
156
157 __REQ_SYNC, /* request is sync (sync write or read) */
158 __REQ_META, /* metadata io request */
159 __REQ_PRIO, /* boost priority in cfq */
160 __REQ_DISCARD, /* request to discard sectors */
161 __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */
162 __REQ_WRITE_SAME, /* write same block many times */
163
164 __REQ_NOIDLE, /* don't anticipate more IO after this one */
165 __REQ_FUA, /* forced unit access */
166 __REQ_FLUSH, /* request for cache flush */
167
168 /* bio only flags */
169 __REQ_RAHEAD, /* read ahead, can fail anytime */
170 __REQ_THROTTLED, /* This bio has already been subjected to
171 * throttling rules. Don't do it again. */
172
173 /* request only flags */
174 __REQ_SORTED, /* elevator knows about this request */
175 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
176 __REQ_NOMERGE, /* don't touch this for merging */
177 __REQ_STARTED, /* drive already may have started this one */
178 __REQ_DONTPREP, /* don't call prep for this one */
179 __REQ_QUEUED, /* uses queueing */
180 __REQ_ELVPRIV, /* elevator private data attached */
181 __REQ_FAILED, /* set if the request failed */
182 __REQ_QUIET, /* don't worry about errors */
183 __REQ_PREEMPT, /* set for "ide_preempt" requests */
184 __REQ_ALLOCED, /* request came from our alloc pool */
185 __REQ_COPY_USER, /* contains copies of user pages */
186 __REQ_FLUSH_SEQ, /* request for flush sequence */
187 __REQ_IO_STAT, /* account I/O stat */
188 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
189 __REQ_KERNEL, /* direct IO to kernel pages */
190 __REQ_PM, /* runtime pm request */
191 __REQ_END, /* last of chain of requests */
192 __REQ_HASHED, /* on IO scheduler merge hash */
193 __REQ_NR_BITS, /* stops here */
194};
195
196#define REQ_WRITE (1ULL << __REQ_WRITE)
197#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
198#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
199#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
200#define REQ_SYNC (1ULL << __REQ_SYNC)
201#define REQ_META (1ULL << __REQ_META)
202#define REQ_PRIO (1ULL << __REQ_PRIO)
203#define REQ_DISCARD (1ULL << __REQ_DISCARD)
204#define REQ_WRITE_SAME (1ULL << __REQ_WRITE_SAME)
205#define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
206
207#define REQ_FAILFAST_MASK \
208 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
209#define REQ_COMMON_MASK \
210 (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
211 REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \
212 REQ_SECURE)
213#define REQ_CLONE_MASK REQ_COMMON_MASK
214
215#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME)
216
217/* This mask is used for both bio and request merge checking */
218#define REQ_NOMERGE_FLAGS \
219 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
220
221#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
222#define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
223
224#define REQ_SORTED (1ULL << __REQ_SORTED)
225#define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
226#define REQ_FUA (1ULL << __REQ_FUA)
227#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
228#define REQ_STARTED (1ULL << __REQ_STARTED)
229#define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
230#define REQ_QUEUED (1ULL << __REQ_QUEUED)
231#define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
232#define REQ_FAILED (1ULL << __REQ_FAILED)
233#define REQ_QUIET (1ULL << __REQ_QUIET)
234#define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
235#define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
236#define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
237#define REQ_FLUSH (1ULL << __REQ_FLUSH)
238#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
239#define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
240#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
241#define REQ_SECURE (1ULL << __REQ_SECURE)
242#define REQ_KERNEL (1ULL << __REQ_KERNEL)
243#define REQ_PM (1ULL << __REQ_PM)
244#define REQ_END (1ULL << __REQ_END)
245#define REQ_HASHED (1ULL << __REQ_HASHED)
246
247#endif /* __LINUX_BLK_TYPES_H */