xref: /linux/fs/bcachefs/io_read.h (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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 
7 struct bch_read_bio {
8 	struct bch_fs		*c;
9 	u64			start_time;
10 	u64			submit_time;
11 
12 	/*
13 	 * Reads will often have to be split, and if the extent being read from
14 	 * was checksummed or compressed we'll also have to allocate bounce
15 	 * buffers and copy the data back into the original bio.
16 	 *
17 	 * If we didn't have to split, we have to save and restore the original
18 	 * bi_end_io - @split below indicates which:
19 	 */
20 	union {
21 	struct bch_read_bio	*parent;
22 	bio_end_io_t		*end_io;
23 	};
24 
25 	/*
26 	 * Saved copy of bio->bi_iter, from submission time - allows us to
27 	 * resubmit on IO error, and also to copy data back to the original bio
28 	 * when we're bouncing:
29 	 */
30 	struct bvec_iter	bvec_iter;
31 
32 	unsigned		offset_into_extent;
33 
34 	u16			flags;
35 	union {
36 	struct {
37 	u16			bounce:1,
38 				split:1,
39 				kmalloc:1,
40 				have_ioref:1,
41 				narrow_crcs:1,
42 				hole:1,
43 				retry:2,
44 				context:2;
45 	};
46 	u16			_state;
47 	};
48 
49 	struct bch_devs_list	devs_have;
50 
51 	struct extent_ptr_decoded pick;
52 
53 	/*
54 	 * pos we read from - different from data_pos for indirect extents:
55 	 */
56 	u32			subvol;
57 	struct bpos		read_pos;
58 
59 	/*
60 	 * start pos of data we read (may not be pos of data we want) - for
61 	 * promote, narrow extents paths:
62 	 */
63 	enum btree_id		data_btree;
64 	struct bpos		data_pos;
65 	struct bversion		version;
66 
67 	struct promote_op	*promote;
68 
69 	struct bch_io_opts	opts;
70 
71 	struct work_struct	work;
72 
73 	struct bio		bio;
74 };
75 
76 #define to_rbio(_bio)		container_of((_bio), struct bch_read_bio, bio)
77 
78 struct bch_devs_mask;
79 struct cache_promote_op;
80 struct extent_ptr_decoded;
81 
82 int __bch2_read_indirect_extent(struct btree_trans *, unsigned *,
83 				struct bkey_buf *);
84 
bch2_read_indirect_extent(struct btree_trans * trans,enum btree_id * data_btree,unsigned * offset_into_extent,struct bkey_buf * k)85 static inline int bch2_read_indirect_extent(struct btree_trans *trans,
86 					    enum btree_id *data_btree,
87 					    unsigned *offset_into_extent,
88 					    struct bkey_buf *k)
89 {
90 	if (k->k->k.type != KEY_TYPE_reflink_p)
91 		return 0;
92 
93 	*data_btree = BTREE_ID_reflink;
94 	return __bch2_read_indirect_extent(trans, offset_into_extent, k);
95 }
96 
97 enum bch_read_flags {
98 	BCH_READ_RETRY_IF_STALE		= 1 << 0,
99 	BCH_READ_MAY_PROMOTE		= 1 << 1,
100 	BCH_READ_USER_MAPPED		= 1 << 2,
101 	BCH_READ_NODECODE		= 1 << 3,
102 	BCH_READ_LAST_FRAGMENT		= 1 << 4,
103 
104 	/* internal: */
105 	BCH_READ_MUST_BOUNCE		= 1 << 5,
106 	BCH_READ_MUST_CLONE		= 1 << 6,
107 	BCH_READ_IN_RETRY		= 1 << 7,
108 };
109 
110 int __bch2_read_extent(struct btree_trans *, struct bch_read_bio *,
111 		       struct bvec_iter, struct bpos, enum btree_id,
112 		       struct bkey_s_c, unsigned,
113 		       struct bch_io_failures *, unsigned);
114 
bch2_read_extent(struct btree_trans * trans,struct bch_read_bio * rbio,struct bpos read_pos,enum btree_id data_btree,struct bkey_s_c k,unsigned offset_into_extent,unsigned flags)115 static inline void bch2_read_extent(struct btree_trans *trans,
116 			struct bch_read_bio *rbio, struct bpos read_pos,
117 			enum btree_id data_btree, struct bkey_s_c k,
118 			unsigned offset_into_extent, unsigned flags)
119 {
120 	__bch2_read_extent(trans, rbio, rbio->bio.bi_iter, read_pos,
121 			   data_btree, k, offset_into_extent, NULL, flags);
122 }
123 
124 void __bch2_read(struct bch_fs *, struct bch_read_bio *, struct bvec_iter,
125 		 subvol_inum, struct bch_io_failures *, unsigned flags);
126 
bch2_read(struct bch_fs * c,struct bch_read_bio * rbio,subvol_inum inum)127 static inline void bch2_read(struct bch_fs *c, struct bch_read_bio *rbio,
128 			     subvol_inum inum)
129 {
130 	struct bch_io_failures failed = { .nr = 0 };
131 
132 	BUG_ON(rbio->_state);
133 
134 	rbio->c = c;
135 	rbio->start_time = local_clock();
136 	rbio->subvol = inum.subvol;
137 
138 	__bch2_read(c, rbio, rbio->bio.bi_iter, inum, &failed,
139 		    BCH_READ_RETRY_IF_STALE|
140 		    BCH_READ_MAY_PROMOTE|
141 		    BCH_READ_USER_MAPPED);
142 }
143 
rbio_init(struct bio * bio,struct bch_io_opts opts)144 static inline struct bch_read_bio *rbio_init(struct bio *bio,
145 					     struct bch_io_opts opts)
146 {
147 	struct bch_read_bio *rbio = to_rbio(bio);
148 
149 	rbio->_state	= 0;
150 	rbio->promote	= NULL;
151 	rbio->opts	= opts;
152 	return rbio;
153 }
154 
155 void bch2_fs_io_read_exit(struct bch_fs *);
156 int bch2_fs_io_read_init(struct bch_fs *);
157 
158 #endif /* _BCACHEFS_IO_READ_H */
159