From 2fe6303e7cd099334cdb09370cece6bc168de131 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Fri, 12 Sep 2014 18:43:59 +0800 Subject: [PATCH] Btrfs: split bio_readpage_error into several functions The data repair function of direct read will be implemented later, and some code in bio_readpage_error will be reused, so split bio_readpage_error into several functions which will be used in direct read repair later. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 159 ++++++++++++++++++++++++++----------------- fs/btrfs/extent_io.h | 28 ++++++++ 2 files changed, 123 insertions(+), 64 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c7648f53f63d..c191ea58750f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1962,25 +1962,6 @@ static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) SetPageUptodate(page); } -/* - * When IO fails, either with EIO or csum verification fails, we - * try other mirrors that might have a good copy of the data. This - * io_failure_record is used to record state as we go through all the - * mirrors. If another mirror has good data, the page is set up to date - * and things continue. If a good mirror can't be found, the original - * bio end_io callback is called to indicate things have failed. - */ -struct io_failure_record { - struct page *page; - u64 start; - u64 len; - u64 logical; - unsigned long bio_flags; - int this_mirror; - int failed_mirror; - int in_validation; -}; - static int free_io_failure(struct inode *inode, struct io_failure_record *rec) { int ret; @@ -2156,40 +2137,24 @@ out: return 0; } -/* - * this is a generic handler for readpage errors (default - * readpage_io_failed_hook). if other copies exist, read those and write back - * good data to the failed position. does not investigate in remapping the - * failed extent elsewhere, hoping the device will be smart enough to do this as - * needed - */ - -static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, - struct page *page, u64 start, u64 end, - int failed_mirror) +int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end, + struct io_failure_record **failrec_ret) { - struct io_failure_record *failrec = NULL; + struct io_failure_record *failrec; u64 private; struct extent_map *em; - struct inode *inode = page->mapping->host; struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; - struct bio *bio; - struct btrfs_io_bio *btrfs_failed_bio; - struct btrfs_io_bio *btrfs_bio; - int num_copies; int ret; - int read_mode; u64 logical; - BUG_ON(failed_bio->bi_rw & REQ_WRITE); - ret = get_state_private(failure_tree, start, &private); if (ret) { failrec = kzalloc(sizeof(*failrec), GFP_NOFS); if (!failrec) return -ENOMEM; + failrec->start = start; failrec->len = end - start + 1; failrec->this_mirror = 0; @@ -2209,11 +2174,11 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, em = NULL; } read_unlock(&em_tree->lock); - if (!em) { kfree(failrec); return -EIO; } + logical = start - em->start; logical = em->block_start + logical; if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { @@ -2222,8 +2187,10 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, extent_set_compress_type(&failrec->bio_flags, em->compress_type); } - pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, " - "len=%llu\n", logical, start, failrec->len); + + pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n", + logical, start, failrec->len); + failrec->logical = logical; free_extent_map(em); @@ -2243,8 +2210,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, } } else { failrec = (struct io_failure_record *)(unsigned long)private; - pr_debug("bio_readpage_error: (found) logical=%llu, " - "start=%llu, len=%llu, validation=%d\n", + pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n", failrec->logical, failrec->start, failrec->len, failrec->in_validation); /* @@ -2253,6 +2219,17 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, * clean_io_failure() clean all those errors at once. */ } + + *failrec_ret = failrec; + + return 0; +} + +int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio, + struct io_failure_record *failrec, int failed_mirror) +{ + int num_copies; + num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, failrec->logical, failrec->len); if (num_copies == 1) { @@ -2261,10 +2238,9 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, * all the retry and error correction code that follows. no * matter what the error is, it is very likely to persist. */ - pr_debug("bio_readpage_error: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", + pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", num_copies, failrec->this_mirror, failed_mirror); - free_io_failure(inode, failrec); - return -EIO; + return 0; } /* @@ -2284,7 +2260,6 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, BUG_ON(failrec->in_validation); failrec->in_validation = 1; failrec->this_mirror = failed_mirror; - read_mode = READ_SYNC | REQ_FAILFAST_DEV; } else { /* * we're ready to fulfill a) and b) alongside. get a good copy @@ -2300,22 +2275,32 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, failrec->this_mirror++; if (failrec->this_mirror == failed_mirror) failrec->this_mirror++; - read_mode = READ_SYNC; } if (failrec->this_mirror > num_copies) { - pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", + pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", num_copies, failrec->this_mirror, failed_mirror); - free_io_failure(inode, failrec); - return -EIO; + return 0; } + return 1; +} + + +struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, + struct io_failure_record *failrec, + struct page *page, int pg_offset, int icsum, + bio_end_io_t *endio_func) +{ + struct bio *bio; + struct btrfs_io_bio *btrfs_failed_bio; + struct btrfs_io_bio *btrfs_bio; + bio = btrfs_io_bio_alloc(GFP_NOFS, 1); - if (!bio) { - free_io_failure(inode, failrec); - return -EIO; - } - bio->bi_end_io = failed_bio->bi_end_io; + if (!bio) + return NULL; + + bio->bi_end_io = endio_func; bio->bi_iter.bi_sector = failrec->logical >> 9; bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; bio->bi_iter.bi_size = 0; @@ -2327,17 +2312,63 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, btrfs_bio = btrfs_io_bio(bio); btrfs_bio->csum = btrfs_bio->csum_inline; - phy_offset >>= inode->i_sb->s_blocksize_bits; - phy_offset *= csum_size; - memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + phy_offset, + icsum *= csum_size; + memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum, csum_size); } - bio_add_page(bio, page, failrec->len, start - page_offset(page)); + bio_add_page(bio, page, failrec->len, pg_offset); + + return bio; +} + +/* + * this is a generic handler for readpage errors (default + * readpage_io_failed_hook). if other copies exist, read those and write back + * good data to the failed position. does not investigate in remapping the + * failed extent elsewhere, hoping the device will be smart enough to do this as + * needed + */ + +static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, + struct page *page, u64 start, u64 end, + int failed_mirror) +{ + struct io_failure_record *failrec; + struct inode *inode = page->mapping->host; + struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; + struct bio *bio; + int read_mode; + int ret; + + BUG_ON(failed_bio->bi_rw & REQ_WRITE); + + ret = btrfs_get_io_failure_record(inode, start, end, &failrec); + if (ret) + return ret; + + ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror); + if (!ret) { + free_io_failure(inode, failrec); + return -EIO; + } + + if (failed_bio->bi_vcnt > 1) + read_mode = READ_SYNC | REQ_FAILFAST_DEV; + else + read_mode = READ_SYNC; + + phy_offset >>= inode->i_sb->s_blocksize_bits; + bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, + start - page_offset(page), + (int)phy_offset, failed_bio->bi_end_io); + if (!bio) { + free_io_failure(inode, failrec); + return -EIO; + } - pr_debug("bio_readpage_error: submitting new read[%#x] to " - "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode, - failrec->this_mirror, num_copies, failrec->in_validation); + pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n", + read_mode, failrec->this_mirror, failrec->in_validation); ret = tree->ops->submit_bio_hook(inode, read_mode, bio, failrec->this_mirror, diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 844b4c5029cd..75b621b7cd9f 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -344,6 +344,34 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start, int end_extent_writepage(struct page *page, int err, u64 start, u64 end); int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb, int mirror_num); + +/* + * When IO fails, either with EIO or csum verification fails, we + * try other mirrors that might have a good copy of the data. This + * io_failure_record is used to record state as we go through all the + * mirrors. If another mirror has good data, the page is set up to date + * and things continue. If a good mirror can't be found, the original + * bio end_io callback is called to indicate things have failed. + */ +struct io_failure_record { + struct page *page; + u64 start; + u64 len; + u64 logical; + unsigned long bio_flags; + int this_mirror; + int failed_mirror; + int in_validation; +}; + +int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end, + struct io_failure_record **failrec_ret); +int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio, + struct io_failure_record *failrec, int fail_mirror); +struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, + struct io_failure_record *failrec, + struct page *page, int pg_offset, int icsum, + bio_end_io_t *endio_func); #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS noinline u64 find_lock_delalloc_range(struct inode *inode, struct extent_io_tree *tree, -- 2.30.2