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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _BCACHEFS_IO_READ_H
3#define _BCACHEFS_IO_READ_H
4
5#include "bkey_buf.h"
6#include "btree_iter.h"
7#include "extents_types.h"
8#include "reflink.h"
9
10struct bch_read_bio {
11 struct bch_fs *c;
12 u64 start_time;
13 u64 submit_time;
14
15 /*
16 * Reads will often have to be split, and if the extent being read from
17 * was checksummed or compressed we'll also have to allocate bounce
18 * buffers and copy the data back into the original bio.
19 *
20 * If we didn't have to split, we have to save and restore the original
21 * bi_end_io - @split below indicates which:
22 */
23 union {
24 struct bch_read_bio *parent;
25 bio_end_io_t *end_io;
26 };
27
28 /*
29 * Saved copy of bio->bi_iter, from submission time - allows us to
30 * resubmit on IO error, and also to copy data back to the original bio
31 * when we're bouncing:
32 */
33 struct bvec_iter bvec_iter;
34
35 unsigned offset_into_extent;
36
37 u16 flags;
38 union {
39 struct {
40 u16 data_update:1,
41 promote:1,
42 bounce:1,
43 split:1,
44 have_ioref:1,
45 narrow_crcs:1,
46 saw_error:1,
47 self_healing:1,
48 context:2;
49 };
50 u16 _state;
51 };
52 s16 ret;
53#ifdef CONFIG_BCACHEFS_ASYNC_OBJECT_LISTS
54 unsigned list_idx;
55#endif
56
57 struct extent_ptr_decoded pick;
58
59 /*
60 * pos we read from - different from data_pos for indirect extents:
61 */
62 u32 subvol;
63 struct bpos read_pos;
64
65 /*
66 * start pos of data we read (may not be pos of data we want) - for
67 * promote, narrow extents paths:
68 */
69 enum btree_id data_btree;
70 struct bpos data_pos;
71 struct bversion version;
72
73 struct bch_io_opts opts;
74
75 struct work_struct work;
76
77 struct bio bio;
78};
79
80#define to_rbio(_bio) container_of((_bio), struct bch_read_bio, bio)
81
82struct bch_devs_mask;
83struct cache_promote_op;
84struct extent_ptr_decoded;
85
86static inline int bch2_read_indirect_extent(struct btree_trans *trans,
87 enum btree_id *data_btree,
88 s64 *offset_into_extent,
89 struct bkey_buf *extent)
90{
91 if (extent->k->k.type != KEY_TYPE_reflink_p)
92 return 0;
93
94 *data_btree = BTREE_ID_reflink;
95
96 struct bch_fs *c = trans->c;
97 struct btree_iter iter;
98 struct bkey_s_c k = bch2_lookup_indirect_extent(trans, &iter,
99 offset_into_extent,
100 bkey_i_to_s_c_reflink_p(extent->k),
101 true, 0);
102 int ret = bkey_err(k);
103 if (ret)
104 return ret;
105
106 if (bkey_deleted(k.k)) {
107 bch2_trans_iter_exit(trans, &iter);
108 return bch_err_throw(c, missing_indirect_extent);
109 }
110
111 bch2_bkey_buf_reassemble(extent, c, k);
112 bch2_trans_iter_exit(trans, &iter);
113 return 0;
114}
115
116#define BCH_READ_FLAGS() \
117 x(retry_if_stale) \
118 x(may_promote) \
119 x(user_mapped) \
120 x(last_fragment) \
121 x(must_bounce) \
122 x(must_clone) \
123 x(in_retry)
124
125enum __bch_read_flags {
126#define x(n) __BCH_READ_##n,
127 BCH_READ_FLAGS()
128#undef x
129};
130
131enum bch_read_flags {
132#define x(n) BCH_READ_##n = BIT(__BCH_READ_##n),
133 BCH_READ_FLAGS()
134#undef x
135};
136
137int __bch2_read_extent(struct btree_trans *, struct bch_read_bio *,
138 struct bvec_iter, struct bpos, enum btree_id,
139 struct bkey_s_c, unsigned,
140 struct bch_io_failures *, unsigned, int);
141
142static inline void bch2_read_extent(struct btree_trans *trans,
143 struct bch_read_bio *rbio, struct bpos read_pos,
144 enum btree_id data_btree, struct bkey_s_c k,
145 unsigned offset_into_extent, unsigned flags)
146{
147 int ret = __bch2_read_extent(trans, rbio, rbio->bio.bi_iter, read_pos,
148 data_btree, k, offset_into_extent, NULL, flags, -1);
149 /* __bch2_read_extent only returns errors if BCH_READ_in_retry is set */
150 WARN(ret, "unhandled error from __bch2_read_extent()");
151}
152
153int __bch2_read(struct btree_trans *, struct bch_read_bio *, struct bvec_iter,
154 subvol_inum,
155 struct bch_io_failures *, struct bkey_buf *, unsigned flags);
156
157static inline void bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
158 subvol_inum inum)
159{
160 BUG_ON(rbio->_state);
161
162 rbio->subvol = inum.subvol;
163
164 bch2_trans_run(c,
165 __bch2_read(trans, rbio, rbio->bio.bi_iter, inum, NULL, NULL,
166 BCH_READ_retry_if_stale|
167 BCH_READ_may_promote|
168 BCH_READ_user_mapped));
169}
170
171static inline struct bch_read_bio *rbio_init_fragment(struct bio *bio,
172 struct bch_read_bio *orig)
173{
174 struct bch_read_bio *rbio = to_rbio(bio);
175
176 rbio->c = orig->c;
177 rbio->_state = 0;
178 rbio->flags = 0;
179 rbio->ret = 0;
180 rbio->split = true;
181 rbio->parent = orig;
182 rbio->opts = orig->opts;
183#ifdef CONFIG_BCACHEFS_ASYNC_OBJECT_LISTS
184 rbio->list_idx = 0;
185#endif
186 return rbio;
187}
188
189static inline struct bch_read_bio *rbio_init(struct bio *bio,
190 struct bch_fs *c,
191 struct bch_io_opts opts,
192 bio_end_io_t end_io)
193{
194 struct bch_read_bio *rbio = to_rbio(bio);
195
196 rbio->start_time = local_clock();
197 rbio->c = c;
198 rbio->_state = 0;
199 rbio->flags = 0;
200 rbio->ret = 0;
201 rbio->opts = opts;
202 rbio->bio.bi_end_io = end_io;
203#ifdef CONFIG_BCACHEFS_ASYNC_OBJECT_LISTS
204 rbio->list_idx = 0;
205#endif
206 return rbio;
207}
208
209struct promote_op;
210void bch2_promote_op_to_text(struct printbuf *, struct promote_op *);
211void bch2_read_bio_to_text(struct printbuf *, struct bch_read_bio *);
212
213void bch2_fs_io_read_exit(struct bch_fs *);
214int bch2_fs_io_read_init(struct bch_fs *);
215
216#endif /* _BCACHEFS_IO_READ_H */