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| author | Zdenek Kabelac <zkabelac@redhat.com> | 2021-09-27 17:14:56 +0200 |
|---|---|---|
| committer | Zdenek Kabelac <zkabelac@redhat.com> | 2021-09-27 18:56:13 +0200 |
| commit | 61a6f9905e87e650f0bddae83fec6923bb100a57 (patch) | |
| tree | f39f328f0247eb2d44ed5dfe9c2901a637107985 | |
| parent | 24e90f9594a79a8be851cffe1a5e47741dbff663 (diff) | |
| download | lvm2-61a6f9905e87e650f0bddae83fec6923bb100a57.tar.gz | |
metadata: optimize reading metadata copies in scan
While being in lockless scanning phase, we can avoid reading and checking
matching metadata copies if we already know them from other PV
and just rely on matching metadata header information.
These copies will be examined later during locked metadata read/write
access.
This patch may postpone discovering some read failures to locked phase.
| -rw-r--r-- | WHATS_NEW | 1 | ||||
| -rw-r--r-- | lib/format_text/format-text.c | 8 |
2 files changed, 7 insertions, 2 deletions
@@ -1,5 +1,6 @@ Version 2.03.14 - ================================== + Reduce metadata readings during scanning phase. Optimize computation of crc32 check sum with multiple PVs. Enhance recover path on cache creation failure. Filter out unsupported MQ/SMQ cache policy setting. diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c index 29efa8ff6..b2bbf3c66 100644 --- a/lib/format_text/format-text.c +++ b/lib/format_text/format-text.c @@ -1570,7 +1570,11 @@ int read_metadata_location_summary(const struct format_type *fmt, /* Keep track of largest metadata size we find. */ lvmcache_save_metadata_size(rlocn->size); - lvmcache_lookup_mda(vgsummary); + if (lvmcache_lookup_mda(vgsummary)) { + log_debug("Skipping read of already known VG metadata with matching mda checksum on %s.", + dev_name(dev_area->dev)); + goto out; + } if (!text_read_metadata_summary(fmt, dev_area->dev, MDA_CONTENT_REASON(primary_mda), (off_t) (dev_area->start + rlocn->offset), @@ -1591,7 +1595,7 @@ int read_metadata_location_summary(const struct format_type *fmt, (unsigned long long)(dev_area->start + rlocn->offset)); return 0; } - +out: log_debug_metadata("Found metadata summary on %s at %llu size %llu for VG %s", dev_name(dev_area->dev), (unsigned long long)(dev_area->start + rlocn->offset), |