From c1fdeec999a427d3b49713901f5b6bf9a2aee00d Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Mon, 1 Jun 2009 12:43:31 +0000 Subject: [PATCH] Fix readahead calculation problems. During vgreduce is failed mirror image replaced with error segment, this segmant type has always area_count == 0. Current code expects that there is at least one area with device, patch fixes it by additional check (fixes segfault during vgreduce). Also do not calculate readahead in every lv_info call, we only need to cache PV readahead before activation calls which locks memory. --- WHATS_NEW | 2 ++ lib/activate/activate.c | 11 ++++++----- lib/activate/dev_manager.c | 2 +- lib/metadata/metadata.c | 19 +++++++++++++------ lib/metadata/metadata.h | 2 +- 5 files changed, 23 insertions(+), 13 deletions(-) diff --git a/WHATS_NEW b/WHATS_NEW index c0840caeb..43705309f 100644 --- a/WHATS_NEW +++ b/WHATS_NEW @@ -1,5 +1,7 @@ Version 2.02.48 - =============================== + Cache underlying device readahead only before activation calls. + Fix segfault when calculating readahead on missing device in vgreduce. Remove verbose 'visited' messages. Handle multi-extent mirror log allocation when smallest PV has only 1 extent. Add LSB standard headers and functions (incl. reload) to clvmd initscript. diff --git a/lib/activate/activate.c b/lib/activate/activate.c index 12e8b20e8..aa75e5b28 100644 --- a/lib/activate/activate.c +++ b/lib/activate/activate.c @@ -469,11 +469,6 @@ static int _lv_info(struct cmd_context *cmd, const struct logical_volume *lv, in info->live_table = dminfo.live_table; info->inactive_table = dminfo.inactive_table; - /* - * Cache read ahead value for PV devices now (before possible suspend) - */ - (void)lv_calculate_readhead(lv); - if (name) dm_pool_free(cmd->mem, name); @@ -879,6 +874,8 @@ static int _lv_suspend(struct cmd_context *cmd, const char *lvid_s, goto out; } + lv_calculate_readahead(lv, NULL); + /* If VG was precommitted, preload devices for the LV */ if ((lv_pre->vg->status & PRECOMMITTED)) { if (!_lv_preload(lv_pre, &flush_required)) { @@ -1010,6 +1007,8 @@ int lv_deactivate(struct cmd_context *cmd, const char *lvid_s) goto out; } + lv_calculate_readahead(lv, NULL); + if (!monitor_dev_for_events(cmd, lv, 0)) stack; @@ -1093,6 +1092,8 @@ static int _lv_activate(struct cmd_context *cmd, const char *lvid_s, goto out; } + lv_calculate_readahead(lv, NULL); + if (exclusive) lv->status |= ACTIVATE_EXCL; diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c index 5a932a696..ab618177a 100644 --- a/lib/activate/dev_manager.c +++ b/lib/activate/dev_manager.c @@ -1023,7 +1023,7 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree, /* we need RA at least twice a whole stripe - see the comment in md/raid0.c */ read_ahead = max_stripe_size * 2; if (!read_ahead) - read_ahead = lv_calculate_readhead(lv); + lv_calculate_readahead(lv, &read_ahead); read_ahead_flags = DM_READ_AHEAD_MINIMUM_FLAG; } diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c index 2b93bfbff..1ee8e5de7 100644 --- a/lib/metadata/metadata.c +++ b/lib/metadata/metadata.c @@ -1422,7 +1422,7 @@ static int _lv_read_ahead_single(struct logical_volume *lv, void *data) struct lv_segment *seg = first_seg(lv); uint32_t seg_read_ahead = 0, *read_ahead = data; - if (seg && seg_type(seg, 0) == AREA_PV) + if (seg && seg->area_count && seg_type(seg, 0) == AREA_PV) dev_get_read_ahead(seg_pv(seg, 0)->dev, &seg_read_ahead); if (seg_read_ahead > *read_ahead) @@ -1431,15 +1431,22 @@ static int _lv_read_ahead_single(struct logical_volume *lv, void *data) return 1; } -uint32_t lv_calculate_readhead(const struct logical_volume *lv) +/* + * Calculate readahead for logical volume from underlying PV devices. + * If read_ahead is NULL, only ensure that readahead of PVs are preloaded + * into PV struct device in dev cache. + */ +void lv_calculate_readahead(const struct logical_volume *lv, uint32_t *read_ahead) { - uint32_t read_ahead = 0; + uint32_t _read_ahead = 0; if (lv->read_ahead == DM_READ_AHEAD_AUTO) - _lv_postorder((struct logical_volume *)lv, _lv_read_ahead_single, &read_ahead); + _lv_postorder((struct logical_volume *)lv, _lv_read_ahead_single, &_read_ahead); - log_debug("Calculated readahead of LV %s is %u", lv->name, read_ahead); - return read_ahead; + if (read_ahead) { + log_debug("Calculated readahead of LV %s is %u", lv->name, _read_ahead); + *read_ahead = _read_ahead; + } } int vg_validate(struct volume_group *vg) diff --git a/lib/metadata/metadata.h b/lib/metadata/metadata.h index 380e6395d..ceb089ccf 100644 --- a/lib/metadata/metadata.h +++ b/lib/metadata/metadata.h @@ -347,7 +347,7 @@ unsigned snapshot_count(const struct volume_group *vg); /* * Calculate readahead from underlying PV devices */ -uint32_t lv_calculate_readhead(const struct logical_volume *lv); +void lv_calculate_readahead(const struct logical_volume *lv, uint32_t *read_ahead); /* * For internal metadata caching.