bio_set_dev sets a bdev to a bio and is not only setting a pointer bug
also changing some state bits if there was a different bdev set before.
This is one thing that's not needed.
Another thing is that setting a bdev at bio allocation time is too early
and actually does not work with plain redundancy profiles, where each
time we submit a bio to a device, the bdev is set correctly.
In many places the bio bdev is set to latest_bdev that seems to serve as
a stub pointer "just to put something to bio". But we don't have to do
that.
Where do we know which bdev to set:
* for regular IO: submit_stripe_bio that's called by btrfs_map_bio
* repair IO: repair_io_failure, read or write from specific device
* super block write (using buffer_heads but uses raw bdev) and barriers
* scrub: this does not use all regular IO paths as it needs to reach all
copies, verify and fixup eventually, and for that all bdev management
is independent
* raid56: rbio_add_io_page, for the RMW write
* integrity-checker: does it's own low-level block tracking
Signed-off-by: David Sterba <dste...@suse.com>
---
fs/btrfs/compression.c | 10 ----------
fs/btrfs/extent_io.c | 2 --
2 files changed, 12 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index b05b361e2062..5e66da73ab34 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -320,7 +320,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode
*inode, u64 start,
int pg_index = 0;
struct page *page;
u64 first_byte = disk_start;
- struct block_device *bdev;
blk_status_t ret;
int skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
@@ -339,10 +338,7 @@ blk_status_t btrfs_submit_compressed_write(struct inode
*inode, u64 start,
cb->orig_bio = NULL;
cb->nr_pages = nr_pages;
- bdev = fs_info->fs_devices->latest_bdev;
-
bio = btrfs_bio_alloc(first_byte);
- bio_set_dev(bio, bdev);
bio->bi_opf = REQ_OP_WRITE | write_flags;
bio->bi_private = cb;
bio->bi_end_io = end_compressed_bio_write;
@@ -385,7 +381,6 @@ blk_status_t btrfs_submit_compressed_write(struct inode
*inode, u64 start,
}
bio = btrfs_bio_alloc(first_byte);
- bio_set_dev(bio, bdev);
bio->bi_opf = REQ_OP_WRITE | write_flags;
bio->bi_private = cb;
bio->bi_end_io = end_compressed_bio_write;
@@ -553,7 +548,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode
*inode, struct bio *bio,
unsigned long nr_pages;
unsigned long pg_index;
struct page *page;
- struct block_device *bdev;
struct bio *comp_bio;
u64 cur_disk_byte = (u64)bio->bi_iter.bi_sector << 9;
u64 em_len;
@@ -604,8 +598,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode
*inode, struct bio *bio,
if (!cb->compressed_pages)
goto fail1;
- bdev = fs_info->fs_devices->latest_bdev;
-
for (pg_index = 0; pg_index < nr_pages; pg_index++) {
cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS |
__GFP_HIGHMEM);
@@ -624,7 +616,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode
*inode, struct bio *bio,
cb->len = bio->bi_iter.bi_size;
comp_bio = btrfs_bio_alloc(cur_disk_byte);
- bio_set_dev(comp_bio, bdev);
comp_bio->bi_opf = REQ_OP_READ;
comp_bio->bi_private = cb;
comp_bio->bi_end_io = end_compressed_bio_read;
@@ -675,7 +666,6 @@ blk_status_t btrfs_submit_compressed_read(struct inode
*inode, struct bio *bio,
}
comp_bio = btrfs_bio_alloc(cur_disk_byte);
- bio_set_dev(comp_bio, bdev);
comp_bio->bi_opf = REQ_OP_READ;
comp_bio->bi_private = cb;
comp_bio->bi_end_io = end_compressed_bio_read;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0f1d917c8bb3..5baade1bc1e1 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2544,7 +2544,6 @@ struct bio *btrfs_create_repair_bio(struct inode *inode,
struct bio *failed_bio,
bio = btrfs_io_bio_alloc(1);
bio->bi_end_io = endio_func;
bio->bi_iter.bi_sector = failrec->logical >> 9;
- bio_set_dev(bio, fs_info->fs_devices->latest_bdev);
bio->bi_iter.bi_size = 0;
bio->bi_private = data;
@@ -2987,7 +2986,6 @@ static int submit_extent_page(unsigned int opf, struct
extent_io_tree *tree,
}
bio = btrfs_bio_alloc(offset);
- bio_set_dev(bio, bdev);
bio_add_page(bio, page, page_size, pg_offset);
bio->bi_end_io = end_io_func;
bio->bi_private = tree;
--
2.23.0
