btrfs: remove btrfs_bio::fs_info by extracting it from btrfs_bio::inode

Currently there is only one caller which doesn't populate
btrfs_bio::inode, and that's scrub.

The idea is scrub doesn't want any automatic csum verification nor
read-repair, as everything will be handled by scrub itself.

However that behavior is really no different than metadata inode, thus
we can reuse btree_inode as btrfs_bio::inode for scrub.

The only exception is in btrfs_submit_chunk() where if a bbio is from
scrub or data reloc inode, we set rst_search_commit_root to true.
This means we still need a way to distinguish scrub from metadata, but
that can be done by a new flag inside btrfs_bio.

Now btrfs_bio::inode is a mandatory parameter, we can extract fs_info
from that inode thus can remove btrfs_bio::fs_info to save 8 bytes from
btrfs_bio structure.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 29 insertions, 22 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 33c9cb91f0a9..3dbb02dbfffb 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -927,10 +927,11 @@ static int calc_next_mirror(int mirror, int num_copies)
 static void scrub_bio_add_sector(struct btrfs_bio *bbio, struct scrub_stripe *stripe,
 				 int sector_nr)
 {
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
 	void *kaddr = scrub_stripe_get_kaddr(stripe, sector_nr);
 	int ret;
 
-	ret = bio_add_page(&bbio->bio, virt_to_page(kaddr), bbio->fs_info->sectorsize,
+	ret = bio_add_page(&bbio->bio, virt_to_page(kaddr), fs_info->sectorsize,
 			   offset_in_page(kaddr));
 	/*
 	 * Caller should ensure the bbio has enough size.
@@ -940,7 +941,21 @@ static void scrub_bio_add_sector(struct btrfs_bio *bbio, struct scrub_stripe *st
 	 * to create the minimal amount of bio vectors, for fs block size < page
 	 * size cases.
 	 */
-	ASSERT(ret == bbio->fs_info->sectorsize);
+	ASSERT(ret == fs_info->sectorsize);
+}
+
+static struct btrfs_bio *alloc_scrub_bbio(struct btrfs_fs_info *fs_info,
+					  unsigned int nr_vecs, blk_opf_t opf,
+					  u64 logical,
+					  btrfs_bio_end_io_t end_io, void *private)
+{
+	struct btrfs_bio *bbio;
+
+	bbio = btrfs_bio_alloc(nr_vecs, opf, BTRFS_I(fs_info->btree_inode),
+			       logical, end_io, private);
+	bbio->is_scrub = true;
+	bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT;
+	return bbio;
 }
 
 static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe,
@@ -966,12 +981,10 @@ static void scrub_stripe_submit_repair_read(struct scrub_stripe *stripe,
 			bbio = NULL;
 		}
 
-		if (!bbio) {
-			bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
-				fs_info, scrub_repair_read_endio, stripe);
-			bbio->bio.bi_iter.bi_sector = (stripe->logical +
-				(i << fs_info->sectorsize_bits)) >> SECTOR_SHIFT;
-		}
+		if (!bbio)
+			bbio = alloc_scrub_bbio(fs_info, stripe->nr_sectors, REQ_OP_READ,
+						stripe->logical + (i << fs_info->sectorsize_bits),
+						scrub_repair_read_endio, stripe);
 
 		scrub_bio_add_sector(bbio, stripe, i);
 	}
@@ -1350,13 +1363,10 @@ static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *str
 			scrub_submit_write_bio(sctx, stripe, bbio, dev_replace);
 			bbio = NULL;
 		}
-		if (!bbio) {
-			bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_WRITE,
-					       fs_info, scrub_write_endio, stripe);
-			bbio->bio.bi_iter.bi_sector = (stripe->logical +
-				(sector_nr << fs_info->sectorsize_bits)) >>
-				SECTOR_SHIFT;
-		}
+		if (!bbio)
+			bbio = alloc_scrub_bbio(fs_info, stripe->nr_sectors, REQ_OP_WRITE,
+					stripe->logical + (sector_nr << fs_info->sectorsize_bits),
+					scrub_write_endio, stripe);
 		scrub_bio_add_sector(bbio, stripe, sector_nr);
 	}
 	if (bbio)
@@ -1847,9 +1857,8 @@ static void scrub_submit_extent_sector_read(struct scrub_stripe *stripe)
 				continue;
 			}
 
-			bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ,
-					       fs_info, scrub_read_endio, stripe);
-			bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT;
+			bbio = alloc_scrub_bbio(fs_info, stripe->nr_sectors, REQ_OP_READ,
+						logical, scrub_read_endio, stripe);
 		}
 
 		scrub_bio_add_sector(bbio, stripe, i);
@@ -1886,10 +1895,8 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx,
 		return;
 	}
 
-	bbio = btrfs_bio_alloc(BTRFS_STRIPE_LEN >> min_folio_shift, REQ_OP_READ, fs_info,
-			       scrub_read_endio, stripe);
-
-	bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
+	bbio = alloc_scrub_bbio(fs_info, BTRFS_STRIPE_LEN >> min_folio_shift, REQ_OP_READ,
+				stripe->logical, scrub_read_endio, stripe);
 	/* Read the whole range inside the chunk boundary. */
 	for (unsigned int cur = 0; cur < nr_sectors; cur++)
 		scrub_bio_add_sector(bbio, stripe, cur);