AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

btrfs: simplify direct I/O read repair

Browse Source 
Direct I/O read repair was originally implemented in commit 8b110e393c
("Btrfs: implement repair function when direct read fails"). This
implementation is unnecessarily complicated. There is major code
duplication between __btrfs_subio_endio_read() (checks checksums and
handles I/O errors for files with checksums),
__btrfs_correct_data_nocsum() (handles I/O errors for files without
checksums), btrfs_retry_endio() (checks checksums and handles I/O errors
for retries of files with checksums), and btrfs_retry_endio_nocsum()
(handles I/O errors for retries of files without checksum). If it sounds
like these should be one function, that's because they should.
Additionally, these functions are very hard to follow due to their
excessive use of goto.

This commit replaces the original implementation. After the previous
commit getting rid of orig_bio, we can reuse the same endio callback for
repair I/O and the original I/O, we just need to track the file offset
and original iterator in the repair bio. We can also unify the handling
of files with and without checksums and simplify the control flow. We
also no longer have to wait for each repair I/O to complete one by one.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Omar Sandoval 2020-04-16 14:46:23 -07:00 committed by David Sterba
parent 769b4f2497
commit fd9d6670ed
2 changed files with 52 additions and 234 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/extent_io.c
View File

@ -2630,6 +2630,8 @@ struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
}
bio_add_page(bio, page, failrec->len, pg_offset);
btrfs_io_bio(bio)->logical = failrec->start;
btrfs_io_bio(bio)->iter = bio->bi_iter;
return bio;
}

284
fs/btrfs/inode.c
View File

@ -7435,19 +7435,17 @@ static int btrfs_check_dio_repairable(struct inode *inode,
static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
struct page *page, unsigned int pgoff,
u64 start, u64 end, int failed_mirror,
bio_end_io_t *repair_endio, void *repair_arg)
u64 start, u64 end, int failed_mirror)
{
struct btrfs_dio_private *dip = failed_bio->bi_private;
struct io_failure_record *failrec;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct bio *bio;
int isector;
unsigned int read_mode = 0;
int segs;
int ret;
blk_status_t status;
struct bio_vec bvec;
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
@ -7462,259 +7460,77 @@ static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
return BLK_STS_IOERR;
}
segs = bio_segments(failed_bio);
bio_get_first_bvec(failed_bio, &bvec);
if (segs > 1 ||
(bvec.bv_len > btrfs_inode_sectorsize(inode)))
if (btrfs_io_bio(failed_bio)->iter.bi_size > inode->i_sb->s_blocksize)
read_mode |= REQ_FAILFAST_DEV;
isector = start - btrfs_io_bio(failed_bio)->logical;
isector >>= inode->i_sb->s_blocksize_bits;
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
pgoff, isector, repair_endio, repair_arg);
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, pgoff,
isector, failed_bio->bi_end_io, dip);
bio->bi_opf = REQ_OP_READ | read_mode;
btrfs_debug(BTRFS_I(inode)->root->fs_info,
"repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
read_mode, failrec->this_mirror, failrec->in_validation);
refcount_inc(&dip->refs);
status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
if (status) {
free_io_failure(failure_tree, io_tree, failrec);
bio_put(bio);
refcount_dec(&dip->refs);
}
return status;
}
struct btrfs_retry_complete {
struct completion done;
struct inode *inode;
u64 start;
int uptodate;
};
static void btrfs_retry_endio_nocsum(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct inode *inode = done->inode;
struct bio_vec *bvec;
struct extent_io_tree *io_tree, *failure_tree;
struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
ASSERT(bio->bi_vcnt == 1);
io_tree = &BTRFS_I(inode)->io_tree;
failure_tree = &BTRFS_I(inode)->io_failure_tree;
ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
done->uptodate = 1;
ASSERT(!bio_flagged(bio, BIO_CLONED));
bio_for_each_segment_all(bvec, bio, iter_all)
clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
io_tree, done->start, bvec->bv_page,
btrfs_ino(BTRFS_I(inode)), 0);
end:
complete(&done->done);
bio_put(bio);
}
static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
struct btrfs_io_bio *io_bio)
{
struct btrfs_fs_info *fs_info;
struct bio_vec bvec;
struct bvec_iter iter;
struct btrfs_retry_complete done;
u64 start;
unsigned int pgoff;
u32 sectorsize;
int nr_sectors;
blk_status_t ret;
blk_status_t err = BLK_STS_OK;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = fs_info->sectorsize;
start = io_bio->logical;
done.inode = inode;
io_bio->bio.bi_iter = io_bio->iter;
bio_for_each_segment(bvec, &io_bio->bio, iter) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
next_block_or_try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num,
btrfs_retry_endio_nocsum, &done);
if (ret) {
err = ret;
goto next;
}
wait_for_completion_io(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto next_block_or_try_again;
}
next:
start += sectorsize;
nr_sectors--;
if (nr_sectors) {
pgoff += sectorsize;
ASSERT(pgoff < PAGE_SIZE);
goto next_block_or_try_again;
}
}
return err;
}
static void btrfs_retry_endio(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct extent_io_tree *io_tree, *failure_tree;
struct inode *inode = done->inode;
struct bio_vec *bvec;
int uptodate;
int ret;
int i = 0;
struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
uptodate = 1;
ASSERT(bio->bi_vcnt == 1);
ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
io_tree = &BTRFS_I(inode)->io_tree;
failure_tree = &BTRFS_I(inode)->io_failure_tree;
ASSERT(!bio_flagged(bio, BIO_CLONED));
bio_for_each_segment_all(bvec, bio, iter_all) {
ret = check_data_csum(inode, io_bio, i, bvec->bv_page,
bvec->bv_offset, done->start,
bvec->bv_len);
if (!ret)
clean_io_failure(BTRFS_I(inode)->root->fs_info,
failure_tree, io_tree, done->start,
bvec->bv_page,
btrfs_ino(BTRFS_I(inode)),
bvec->bv_offset);
else
uptodate = 0;
i++;
}
done->uptodate = uptodate;
end:
complete(&done->done);
bio_put(bio);
}
static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, blk_status_t err)
{
struct btrfs_fs_info *fs_info;
struct bio_vec bvec;
struct bvec_iter iter;
struct btrfs_retry_complete done;
u64 start;
u64 offset = 0;
u32 sectorsize;
int nr_sectors;
unsigned int pgoff;
int csum_pos;
bool uptodate = (err == 0);
int ret;
blk_status_t status;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = fs_info->sectorsize;
err = BLK_STS_OK;
start = io_bio->logical;
done.inode = inode;
io_bio->bio.bi_iter = io_bio->iter;
bio_for_each_segment(bvec, &io_bio->bio, iter) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
next_block:
if (uptodate) {
csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
ret = check_data_csum(inode, io_bio, csum_pos,
bvec.bv_page, pgoff, start,
sectorsize);
if (likely(!ret))
goto next;
}
try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num, btrfs_retry_endio,
&done);
if (status) {
err = status;
goto next;
}
wait_for_completion_io(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto try_again;
}
next:
offset += sectorsize;
start += sectorsize;
ASSERT(nr_sectors);
nr_sectors--;
if (nr_sectors) {
pgoff += sectorsize;
ASSERT(pgoff < PAGE_SIZE);
goto next_block;
}
}
return err;
}
static blk_status_t btrfs_check_read_dio_bio(struct inode *inode,
struct btrfs_io_bio *io_bio,
blk_status_t err)
const bool uptodate)
{
bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
const u32 sectorsize = fs_info->sectorsize;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
struct bio_vec bvec;
struct bvec_iter iter;
u64 start = io_bio->logical;
int icsum = 0;
blk_status_t err = BLK_STS_OK;
if (skip_csum) {
if (unlikely(err))
return __btrfs_correct_data_nocsum(inode, io_bio);
else
return BLK_STS_OK;
} else {
return __btrfs_subio_endio_read(inode, io_bio, err);
__bio_for_each_segment(bvec, &io_bio->bio, iter, io_bio->iter) {
unsigned int i, nr_sectors, pgoff;
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
for (i = 0; i < nr_sectors; i++) {
ASSERT(pgoff < PAGE_SIZE);
if (uptodate &&
(!csum || !check_data_csum(inode, io_bio, icsum,
bvec.bv_page, pgoff,
start, sectorsize))) {
clean_io_failure(fs_info, failure_tree, io_tree,
start, bvec.bv_page,
btrfs_ino(BTRFS_I(inode)),
pgoff);
} else {
blk_status_t status;
status = dio_read_error(inode, &io_bio->bio,
bvec.bv_page, pgoff,
start,
start + sectorsize - 1,
io_bio->mirror_num);
if (status)
err = status;
}
start += sectorsize;
icsum++;
pgoff += sectorsize;
}
}
return err;
}
static void __endio_write_update_ordered(struct inode *inode,
@ -7785,7 +7601,7 @@ static void btrfs_end_dio_bio(struct bio *bio)
if (bio_op(bio) == REQ_OP_READ) {
err = btrfs_check_read_dio_bio(dip->inode, btrfs_io_bio(bio),
err);
!err);
}
if (err)