]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - include/linux/blk_types.h
block: simplify and cleanup bvec pool handling
[mirror_ubuntu-artful-kernel.git] / include / linux / blk_types.h
CommitLineData
7cc01581
TH
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
7cc01581
TH
8#include <linux/types.h>
9
10struct bio_set;
11struct bio;
12struct bio_integrity_payload;
13struct page;
14struct block_device;
852c788f
TH
15struct io_context;
16struct cgroup_subsys_state;
4246a0b6 17typedef void (bio_end_io_t) (struct bio *);
7cc01581
TH
18typedef 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 */
23struct bio_vec {
24 struct page *bv_page;
25 unsigned int bv_len;
26 unsigned int bv_offset;
27};
28
62a8067a
AV
29#ifdef CONFIG_BLOCK
30
4f024f37
KO
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 */
4550dd6c
KO
37
38 unsigned int bi_bvec_done; /* number of bytes completed in
39 current bvec */
4f024f37
KO
40};
41
7cc01581
TH
42/*
43 * main unit of I/O for the block layer and lower layers (ie drivers and
44 * stacking drivers)
45 */
46struct bio {
7cc01581
TH
47 struct bio *bi_next; /* request queue link */
48 struct block_device *bi_bdev;
2c68f6dc
JA
49 unsigned int bi_flags; /* status, command, etc */
50 int bi_error;
4e1b2d52
MC
51 unsigned int bi_rw; /* bottom bits req flags,
52 * top bits REQ_OP
53 */
43b62ce3 54 unsigned short bi_ioprio;
7cc01581 55
4f024f37 56 struct bvec_iter bi_iter;
7cc01581
TH
57
58 /* Number of segments in this BIO after
59 * physical address coalescing is performed.
60 */
61 unsigned int bi_phys_segments;
62
7cc01581
TH
63 /*
64 * To keep track of the max segment size, we account for the
65 * sizes of the first and last mergeable segments in this bio.
66 */
67 unsigned int bi_seg_front_size;
68 unsigned int bi_seg_back_size;
69
c4cf5261 70 atomic_t __bi_remaining;
196d38bc 71
7cc01581
TH
72 bio_end_io_t *bi_end_io;
73
74 void *bi_private;
852c788f
TH
75#ifdef CONFIG_BLK_CGROUP
76 /*
77 * Optional ioc and css associated with this bio. Put on bio
78 * release. Read comment on top of bio_associate_current().
79 */
80 struct io_context *bi_ioc;
81 struct cgroup_subsys_state *bi_css;
82#endif
180b2f95 83 union {
7cc01581 84#if defined(CONFIG_BLK_DEV_INTEGRITY)
180b2f95 85 struct bio_integrity_payload *bi_integrity; /* data integrity */
7cc01581 86#endif
180b2f95 87 };
7cc01581 88
4f024f37
KO
89 unsigned short bi_vcnt; /* how many bio_vec's */
90
f44b48c7
KO
91 /*
92 * Everything starting with bi_max_vecs will be preserved by bio_reset()
93 */
94
4f024f37 95 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
f44b48c7 96
dac56212 97 atomic_t __bi_cnt; /* pin count */
f44b48c7
KO
98
99 struct bio_vec *bi_io_vec; /* the actual vec list */
100
395c72a7
KO
101 struct bio_set *bi_pool;
102
7cc01581
TH
103 /*
104 * We can inline a number of vecs at the end of the bio, to avoid
105 * double allocations for a small number of bio_vecs. This member
106 * MUST obviously be kept at the very end of the bio.
107 */
108 struct bio_vec bi_inline_vecs[0];
109};
110
4e1b2d52
MC
111#define BIO_OP_SHIFT (8 * sizeof(unsigned int) - REQ_OP_BITS)
112#define bio_op(bio) ((bio)->bi_rw >> BIO_OP_SHIFT)
113
114#define bio_set_op_attrs(bio, op, op_flags) do { \
115 WARN_ON(op >= (1 << REQ_OP_BITS)); \
116 (bio)->bi_rw &= ((1 << BIO_OP_SHIFT) - 1); \
117 (bio)->bi_rw |= ((unsigned int) (op) << BIO_OP_SHIFT); \
118 (bio)->bi_rw |= op_flags; \
119} while (0)
120
f44b48c7
KO
121#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
122
7cc01581
TH
123/*
124 * bio flags
125 */
b2dbe0a6
JA
126#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
127#define BIO_CLONED 2 /* doesn't own data */
128#define BIO_BOUNCED 3 /* bio is a bounce bio */
129#define BIO_USER_MAPPED 4 /* contains user pages */
130#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
131#define BIO_QUIET 6 /* Make BIO Quiet */
a3ad0a9d
JK
132#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
133#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
f44b48c7
KO
134
135/*
136 * Flags starting here get preserved by bio_reset() - this includes
ed996a52 137 * BVEC_POOL_IDX()
f44b48c7 138 */
71368511 139#define BIO_RESET_BITS 13
f44b48c7 140
7cc01581 141/*
ed996a52
CH
142 * We support 6 different bvec pools, the last one is magic in that it
143 * is backed by a mempool.
7cc01581 144 */
ed996a52
CH
145#define BVEC_POOL_NR 6
146#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
147
148/*
149 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add
150 * 1 to the actual index so that 0 indicates that there are no bvecs to be
151 * freed.
152 */
153#define BVEC_POOL_BITS (4)
154#define BVEC_POOL_OFFSET (32 - BVEC_POOL_BITS)
155#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
7cc01581 156
de75d60d
JA
157#endif /* CONFIG_BLOCK */
158
7cc01581
TH
159/*
160 * Request flags. For use in the cmd_flags field of struct request, and in
161 * bi_rw of struct bio. Note that some flags are only valid in either one.
162 */
163enum rq_flag_bits {
164 /* common flags */
7cc01581
TH
165 __REQ_FAILFAST_DEV, /* no driver retries of device errors */
166 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
167 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
168
7cc01581
TH
169 __REQ_SYNC, /* request is sync (sync write or read) */
170 __REQ_META, /* metadata io request */
65299a3b 171 __REQ_PRIO, /* boost priority in cfq */
8e4bf844 172
7cc01581 173 __REQ_NOIDLE, /* don't anticipate more IO after this one */
180b2f95 174 __REQ_INTEGRITY, /* I/O includes block integrity payload */
8e4bf844 175 __REQ_FUA, /* forced unit access */
28a8f0d3 176 __REQ_PREFLUSH, /* request for cache flush */
7cc01581
TH
177
178 /* bio only flags */
7cc01581 179 __REQ_RAHEAD, /* read ahead, can fail anytime */
e43473b7
VG
180 __REQ_THROTTLED, /* This bio has already been subjected to
181 * throttling rules. Don't do it again. */
7cc01581
TH
182
183 /* request only flags */
184 __REQ_SORTED, /* elevator knows about this request */
185 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
7cc01581
TH
186 __REQ_NOMERGE, /* don't touch this for merging */
187 __REQ_STARTED, /* drive already may have started this one */
188 __REQ_DONTPREP, /* don't call prep for this one */
189 __REQ_QUEUED, /* uses queueing */
190 __REQ_ELVPRIV, /* elevator private data attached */
191 __REQ_FAILED, /* set if the request failed */
192 __REQ_QUIET, /* don't worry about errors */
bba0bdd7
BVA
193 __REQ_PREEMPT, /* set for "ide_preempt" requests and also
194 for requests for which the SCSI "quiesce"
195 state must be ignored. */
7cc01581
TH
196 __REQ_ALLOCED, /* request came from our alloc pool */
197 __REQ_COPY_USER, /* contains copies of user pages */
414b4ff5 198 __REQ_FLUSH_SEQ, /* request for flush sequence */
7cc01581
TH
199 __REQ_IO_STAT, /* account I/O stat */
200 __REQ_MIXED_MERGE, /* merge of different types, fail separately */
66311274 201 __REQ_PM, /* runtime pm request */
360f92c2 202 __REQ_HASHED, /* on IO scheduler merge hash */
0d2602ca 203 __REQ_MQ_INFLIGHT, /* track inflight for MQ */
7cc01581
TH
204 __REQ_NR_BITS, /* stops here */
205};
206
5953316d
JA
207#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
208#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
209#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
210#define REQ_SYNC (1ULL << __REQ_SYNC)
211#define REQ_META (1ULL << __REQ_META)
212#define REQ_PRIO (1ULL << __REQ_PRIO)
5953316d 213#define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
180b2f95 214#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
7cc01581
TH
215
216#define REQ_FAILFAST_MASK \
217 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
218#define REQ_COMMON_MASK \
4e1b2d52 219 (REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \
288dab8a 220 REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE)
3a2edd0d 221#define REQ_CLONE_MASK REQ_COMMON_MASK
7cc01581 222
e2a60da7
MP
223/* This mask is used for both bio and request merge checking */
224#define REQ_NOMERGE_FLAGS \
28a8f0d3 225 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_PREFLUSH | REQ_FUA | REQ_FLUSH_SEQ)
e2a60da7 226
5953316d
JA
227#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
228#define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
229
230#define REQ_SORTED (1ULL << __REQ_SORTED)
231#define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
232#define REQ_FUA (1ULL << __REQ_FUA)
233#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
234#define REQ_STARTED (1ULL << __REQ_STARTED)
235#define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
236#define REQ_QUEUED (1ULL << __REQ_QUEUED)
237#define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
238#define REQ_FAILED (1ULL << __REQ_FAILED)
239#define REQ_QUIET (1ULL << __REQ_QUIET)
240#define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
241#define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
242#define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
28a8f0d3 243#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
5953316d
JA
244#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
245#define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
246#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
5953316d 247#define REQ_PM (1ULL << __REQ_PM)
360f92c2 248#define REQ_HASHED (1ULL << __REQ_HASHED)
0d2602ca 249#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)
7cc01581 250
f2150821
MC
251enum req_op {
252 REQ_OP_READ,
4e1b2d52
MC
253 REQ_OP_WRITE,
254 REQ_OP_DISCARD, /* request to discard sectors */
288dab8a 255 REQ_OP_SECURE_ERASE, /* request to securely erase sectors */
4e1b2d52 256 REQ_OP_WRITE_SAME, /* write same block many times */
3a5e02ce 257 REQ_OP_FLUSH, /* request for cache flush */
f2150821
MC
258};
259
3a5e02ce 260#define REQ_OP_BITS 3
f2150821 261
dece1635
JA
262typedef unsigned int blk_qc_t;
263#define BLK_QC_T_NONE -1U
264#define BLK_QC_T_SHIFT 16
265
266static inline bool blk_qc_t_valid(blk_qc_t cookie)
267{
268 return cookie != BLK_QC_T_NONE;
269}
270
271static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num)
272{
273 return tag | (queue_num << BLK_QC_T_SHIFT);
274}
275
276static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
277{
278 return cookie >> BLK_QC_T_SHIFT;
279}
280
281static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
282{
e3a7a3bf 283 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
dece1635
JA
284}
285
7cc01581 286#endif /* __LINUX_BLK_TYPES_H */