From: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> Do not bother with locked clusters. For llseek we can ignore all concurrent operations. Do not call ploop_bat_entries() on every cluster as this is slow. Just remember md and read it directly.
https://virtuozzo.atlassian.net/browse/VSTOR-91817 Signed-off-by: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> --- drivers/md/dm-ploop-map.c | 27 ++++++++------------------- 1 file changed, 8 insertions(+), 19 deletions(-) diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c index 90b408337c13..014124d20988 100644 --- a/drivers/md/dm-ploop-map.c +++ b/drivers/md/dm-ploop-map.c @@ -2084,32 +2084,21 @@ ALLOW_ERROR_INJECTION(ploop_prepare_reloc_index_wb, ERRNO); loff_t ploop_llseek_hole(struct dm_target *ti, loff_t offset, int whence) { struct ploop *ploop = ti->private; - u32 clu, dst_clu; + u32 clu, dst_clu, id, *bat; + struct md_page *md; loff_t result; clu = SEC_TO_CLU(ploop, to_sector(offset) + ploop->skip_off); + id = U32_MAX; while (clu < ploop->nr_bat_entries) { - - /* - * Assume a locked cluster to have a data. - * In worst case someone will read zeroes - */ - if (ploop_postpone_if_cluster_locked(ploop, NULL, clu)) { - if (whence & SEEK_DATA) - break; - if (whence & SEEK_HOLE) { - clu++; - continue; - } + if (id != ploop_bat_clu_to_page_nr(clu)) { + id = ploop_bat_clu_to_page_nr(clu); + md = ploop_md_page_find(ploop, id); } - /* - * It *may* be possible to speed this up by iterating over clusters - * in mapped metadata page, but this is a bit problematic - * since we want to check if cluster is locked - */ - dst_clu = ploop_bat_entries(ploop, clu, NULL, NULL); + bat = md->kmpage; + dst_clu = READ_ONCE(bat[ploop_bat_clu_idx_in_page(clu)]); if (whence & SEEK_DATA && dst_clu != BAT_ENTRY_NONE) break; -- 2.43.0 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
