From cb2ced73d8c7a38b5f699e267deadf2a2cfe911c Mon Sep 17 00:00:00 2001 From: Stefan Behrens Date: Fri, 2 Nov 2012 16:14:21 +0100 Subject: Btrfs: in scrub repair code, optimize the reading of mirrors In case that disk blocks need to be repaired (rewritten), the current code at first (for simplicity reasons) reads all alternate mirrors in the first step, afterwards selects the best one in a second step. This is now changed to read one alternate mirror after the other and to leave the loop early when a perfect mirror is found. Signed-off-by: Stefan Behrens Signed-off-by: Chris Mason --- fs/btrfs/scrub.c | 35 ++++++++++++----------------------- 1 file changed, 12 insertions(+), 23 deletions(-) (limited to 'fs/btrfs/scrub.c') diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 15ac82ae5770..7d38f4073243 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -819,26 +819,8 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) /* * now build and submit the bios for the other mirrors, check - * checksums - */ - for (mirror_index = 0; - mirror_index < BTRFS_MAX_MIRRORS && - sblocks_for_recheck[mirror_index].page_count > 0; - mirror_index++) { - if (mirror_index == failed_mirror_index) - continue; - - /* build and submit the bios, check checksums */ - ret = scrub_recheck_block(fs_info, - sblocks_for_recheck + mirror_index, - is_metadata, have_csum, csum, - generation, sctx->csum_size); - if (ret) - goto did_not_correct_error; - } - - /* - * first try to pick the mirror which is completely without I/O + * checksums. + * First try to pick the mirror which is completely without I/O * errors and also does not have a checksum error. * If one is found, and if a checksum is present, the full block * that is known to contain an error is rewritten. Afterwards @@ -854,10 +836,17 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) mirror_index < BTRFS_MAX_MIRRORS && sblocks_for_recheck[mirror_index].page_count > 0; mirror_index++) { - struct scrub_block *sblock_other = sblocks_for_recheck + - mirror_index; + struct scrub_block *sblock_other; - if (!sblock_other->header_error && + if (mirror_index == failed_mirror_index) + continue; + sblock_other = sblocks_for_recheck + mirror_index; + + /* build and submit the bios, check checksums */ + ret = scrub_recheck_block(fs_info, sblock_other, is_metadata, + have_csum, csum, generation, + sctx->csum_size); + if (!ret && !sblock_other->header_error && !sblock_other->checksum_error && sblock_other->no_io_error_seen) { int force_write = is_metadata || have_csum; -- cgit v1.2.3-58-ga151