bcachefs: bch2_io_opts_fixups()

Centralize some io path option fixups - they weren't always being
applied correctly:

- background_compression uses compression if unset
- background_target uses foreground_target if unset
- nocow disables most fancy io path options

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/data_update.c

@@ -535,7 +535,7 @@ void bch2_data_update_opts_to_text(struct printbuf *out, struct bch_fs *c,
 	prt_newline(out);
 
 	prt_str(out, "compression:\t");
-	bch2_compression_opt_to_text(out, background_compression(*io_opts));
+	bch2_compression_opt_to_text(out, io_opts->background_compression);
 	prt_newline(out);
 
 	prt_str(out, "opts.replicas:\t");
@@ -647,7 +647,7 @@ int bch2_data_update_init(struct btree_trans *trans,
 		BCH_WRITE_DATA_ENCODED|
 		BCH_WRITE_MOVE|
 		m->data_opts.write_flags;
-	m->op.compression_opt	= background_compression(io_opts);
+	m->op.compression_opt	= io_opts.background_compression;
 	m->op.watermark		= m->data_opts.btree_insert_flags & BCH_WATERMARK_MASK;
 
 	unsigned durability_have = 0, durability_removing = 0;

fs/bcachefs/extents.c

@@ -1504,7 +1504,7 @@ int bch2_bkey_set_needs_rebalance(struct bch_fs *c, struct bkey_i *_k,
 	struct bkey_s k = bkey_i_to_s(_k);
 	struct bch_extent_rebalance *r;
 	unsigned target = opts->background_target;
-	unsigned compression = background_compression(*opts);
+	unsigned compression = opts->background_compression;
 	bool needs_rebalance;
 
 	if (!bkey_extent_is_direct_data(k.k))

fs/bcachefs/inode.c

@@ -14,6 +14,7 @@
 #include "extent_update.h"
 #include "fs.h"
 #include "inode.h"
+#include "opts.h"
 #include "str_hash.h"
 #include "snapshot.h"
 #include "subvolume.h"
@@ -1145,8 +1146,7 @@ void bch2_inode_opts_get(struct bch_io_opts *opts, struct bch_fs *c,
 	BCH_INODE_OPTS()
 #undef x
 
-	if (opts->nocow)
-		opts->compression = opts->background_compression = opts->data_checksum = opts->erasure_code = 0;
+	bch2_io_opts_fixups(opts);
 }
 
 int bch2_inum_opts_get(struct btree_trans *trans, subvol_inum inum, struct bch_io_opts *opts)

fs/bcachefs/opts.c

@@ -710,11 +710,14 @@ void bch2_opt_set_sb(struct bch_fs *c, struct bch_dev *ca,
 
 struct bch_io_opts bch2_opts_to_inode_opts(struct bch_opts src)
 {
-	return (struct bch_io_opts) {
+	struct bch_io_opts opts = {
 #define x(_name, _bits)	._name = src._name,
 	BCH_INODE_OPTS()
 #undef x
 	};
+
+	bch2_io_opts_fixups(&opts);
+	return opts;
 }
 
 bool bch2_opt_is_inode_opt(enum bch_opt_id id)

fs/bcachefs/opts.h

@@ -626,9 +626,17 @@ struct bch_io_opts {
 #undef x
 };
 
-static inline unsigned background_compression(struct bch_io_opts opts)
+static inline void bch2_io_opts_fixups(struct bch_io_opts *opts)
 {
-	return opts.background_compression ?: opts.compression;
+	if (!opts->background_target)
+		opts->background_target = opts->foreground_target;
+	if (!opts->background_compression)
+		opts->background_compression = opts->compression;
+	if (opts->nocow) {
+		opts->compression = opts->background_compression = 0;
+		opts->data_checksum = 0;
+		opts->erasure_code = 0;
+	}
 }
 
 struct bch_io_opts bch2_opts_to_inode_opts(struct bch_opts);

fs/bcachefs/rebalance.c

@@ -257,12 +257,12 @@ static bool rebalance_pred(struct bch_fs *c, void *arg,
 
 	if (k.k->p.inode) {
 		target		= io_opts->background_target;
-		compression	= background_compression(*io_opts);
+		compression	= io_opts->background_compression;
 	} else {
 		const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k);
 
 		target		= r ? r->target : io_opts->background_target;
-		compression	= r ? r->compression : background_compression(*io_opts);
+		compression	= r ? r->compression : io_opts->background_compression;
 	}
 
 	data_opts->rewrite_ptrs		= bch2_bkey_ptrs_need_rebalance(c, k, target, compression);