linux/fs/bcachefs/compress.h
Kent Overstreet fb3f57bb11 bcachefs: rebalance_work
This adds a new btree, rebalance_work, to eliminate scanning required
for finding extents that need work done on them in the background - i.e.
for the background_target and background_compression options.

rebalance_work is a bitset btree, where a KEY_TYPE_set corresponds to an
extent in the extents or reflink btree at the same pos.

A new extent field is added, bch_extent_rebalance, which indicates that
this extent has work that needs to be done in the background - and which
options to use. This allows per-inode options to be propagated to
indirect extents - at least in some circumstances. In this patch,
changing IO options on a file will not propagate the new options to
indirect extents pointed to by that file.

Updating (setting/clearing) the rebalance_work btree is done by the
extent trigger, which looks at the bch_extent_rebalance field.

Scanning is still requrired after changing IO path options - either just
for a given inode, or for the whole filesystem. We indicate that
scanning is required by adding a KEY_TYPE_cookie key to the
rebalance_work btree: the cookie counter is so that we can detect that
scanning is still required when an option has been flipped mid-way
through an existing scan.

Future possible work:
 - Propagate options to indirect extents when being changed
 - Add other IO path options - nr_replicas, ec, to rebalance_work so
   they can be applied in the background when they change
 - Add a counter, for bcachefs fs usage output, showing the pending
   amount of rebalance work: we'll probably want to do this after the
   disk space accounting rewrite (moving it to a new btree)

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-01 21:11:05 -04:00

74 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_COMPRESS_H
#define _BCACHEFS_COMPRESS_H
#include "extents_types.h"
static const unsigned __bch2_compression_opt_to_type[] = {
#define x(t, n) [BCH_COMPRESSION_OPT_##t] = BCH_COMPRESSION_TYPE_##t,
BCH_COMPRESSION_OPTS()
#undef x
};
struct bch_compression_opt {
u8 type:4,
level:4;
};
static inline struct bch_compression_opt __bch2_compression_decode(unsigned v)
{
return (struct bch_compression_opt) {
.type = v & 15,
.level = v >> 4,
};
}
static inline bool bch2_compression_opt_valid(unsigned v)
{
struct bch_compression_opt opt = __bch2_compression_decode(v);
return opt.type < ARRAY_SIZE(__bch2_compression_opt_to_type) && !(!opt.type && opt.level);
}
static inline struct bch_compression_opt bch2_compression_decode(unsigned v)
{
return bch2_compression_opt_valid(v)
? __bch2_compression_decode(v)
: (struct bch_compression_opt) { 0 };
}
static inline unsigned bch2_compression_encode(struct bch_compression_opt opt)
{
return opt.type|(opt.level << 4);
}
static inline enum bch_compression_type bch2_compression_opt_to_type(unsigned v)
{
return __bch2_compression_opt_to_type[bch2_compression_decode(v).type];
}
int bch2_bio_uncompress_inplace(struct bch_fs *, struct bio *,
struct bch_extent_crc_unpacked *);
int bch2_bio_uncompress(struct bch_fs *, struct bio *, struct bio *,
struct bvec_iter, struct bch_extent_crc_unpacked);
unsigned bch2_bio_compress(struct bch_fs *, struct bio *, size_t *,
struct bio *, size_t *, unsigned);
int bch2_check_set_has_compressed_data(struct bch_fs *, unsigned);
void bch2_fs_compress_exit(struct bch_fs *);
int bch2_fs_compress_init(struct bch_fs *);
void bch2_compression_opt_to_text(struct printbuf *, u64);
int bch2_opt_compression_parse(struct bch_fs *, const char *, u64 *, struct printbuf *);
void bch2_opt_compression_to_text(struct printbuf *, struct bch_fs *, struct bch_sb *, u64);
int bch2_opt_compression_validate(u64, struct printbuf *);
#define bch2_opt_compression (struct bch_opt_fn) { \
.parse = bch2_opt_compression_parse, \
.to_text = bch2_opt_compression_to_text, \
.validate = bch2_opt_compression_validate, \
}
#endif /* _BCACHEFS_COMPRESS_H */