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Diffstat (limited to '')
| -rw-r--r-- | fs/bcachefs/io_read.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/fs/bcachefs/io_read.h b/fs/bcachefs/io_read.h new file mode 100644 index 0000000000..d9c18bb7d4 --- /dev/null +++ b/fs/bcachefs/io_read.h @@ -0,0 +1,158 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHEFS_IO_READ_H +#define _BCACHEFS_IO_READ_H + +#include "bkey_buf.h" + +struct bch_read_bio { + struct bch_fs *c; + u64 start_time; + u64 submit_time; + + /* + * Reads will often have to be split, and if the extent being read from + * was checksummed or compressed we'll also have to allocate bounce + * buffers and copy the data back into the original bio. + * + * If we didn't have to split, we have to save and restore the original + * bi_end_io - @split below indicates which: + */ + union { + struct bch_read_bio *parent; + bio_end_io_t *end_io; + }; + + /* + * Saved copy of bio->bi_iter, from submission time - allows us to + * resubmit on IO error, and also to copy data back to the original bio + * when we're bouncing: + */ + struct bvec_iter bvec_iter; + + unsigned offset_into_extent; + + u16 flags; + union { + struct { + u16 bounce:1, + split:1, + kmalloc:1, + have_ioref:1, + narrow_crcs:1, + hole:1, + retry:2, + context:2; + }; + u16 _state; + }; + + struct bch_devs_list devs_have; + + struct extent_ptr_decoded pick; + + /* + * pos we read from - different from data_pos for indirect extents: + */ + u32 subvol; + struct bpos read_pos; + + /* + * start pos of data we read (may not be pos of data we want) - for + * promote, narrow extents paths: + */ + enum btree_id data_btree; + struct bpos data_pos; + struct bversion version; + + struct promote_op *promote; + + struct bch_io_opts opts; + + struct work_struct work; + + struct bio bio; +}; + +#define to_rbio(_bio) container_of((_bio), struct bch_read_bio, bio) + +struct bch_devs_mask; +struct cache_promote_op; +struct extent_ptr_decoded; + +int __bch2_read_indirect_extent(struct btree_trans *, unsigned *, + struct bkey_buf *); + +static inline int bch2_read_indirect_extent(struct btree_trans *trans, + enum btree_id *data_btree, + unsigned *offset_into_extent, + struct bkey_buf *k) +{ + if (k->k->k.type != KEY_TYPE_reflink_p) + return 0; + + *data_btree = BTREE_ID_reflink; + return __bch2_read_indirect_extent(trans, offset_into_extent, k); +} + +enum bch_read_flags { + BCH_READ_RETRY_IF_STALE = 1 << 0, + BCH_READ_MAY_PROMOTE = 1 << 1, + BCH_READ_USER_MAPPED = 1 << 2, + BCH_READ_NODECODE = 1 << 3, + BCH_READ_LAST_FRAGMENT = 1 << 4, + + /* internal: */ + BCH_READ_MUST_BOUNCE = 1 << 5, + BCH_READ_MUST_CLONE = 1 << 6, + BCH_READ_IN_RETRY = 1 << 7, +}; + +int __bch2_read_extent(struct btree_trans *, struct bch_read_bio *, + struct bvec_iter, struct bpos, enum btree_id, + struct bkey_s_c, unsigned, + struct bch_io_failures *, unsigned); + +static inline void 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) +{ + __bch2_read_extent(trans, rbio, rbio->bio.bi_iter, read_pos, + data_btree, k, offset_into_extent, NULL, flags); +} + +void __bch2_read(struct bch_fs *, struct bch_read_bio *, struct bvec_iter, + subvol_inum, struct bch_io_failures *, unsigned flags); + +static inline void bch2_read(struct bch_fs *c, struct bch_read_bio *rbio, + subvol_inum inum) +{ + struct bch_io_failures failed = { .nr = 0 }; + + BUG_ON(rbio->_state); + + rbio->c = c; + rbio->start_time = local_clock(); + rbio->subvol = inum.subvol; + + __bch2_read(c, rbio, rbio->bio.bi_iter, inum, &failed, + BCH_READ_RETRY_IF_STALE| + BCH_READ_MAY_PROMOTE| + BCH_READ_USER_MAPPED); +} + +static inline struct bch_read_bio *rbio_init(struct bio *bio, + struct bch_io_opts opts) +{ + struct bch_read_bio *rbio = to_rbio(bio); + + rbio->_state = 0; + rbio->promote = NULL; + rbio->opts = opts; + return rbio; +} + +void bch2_fs_io_read_exit(struct bch_fs *); +int bch2_fs_io_read_init(struct bch_fs *); + +#endif /* _BCACHEFS_IO_READ_H */ |