Zdenek Kabelac [Fri, 1 Oct 2021 14:19:53 +0000 (16:19 +0200)]
archiving: refactor code to allocate less memory
Do not store full path with each archived name reduces memory usage if
the directory has thousands of entries and just add 'dir' path when
needed.
Also emit info print message to a user if the total size of archived
files for a VG is more then 128MiB or 8192 files.
TODO: Consider wheather adding a new 'lvm.conf archive{option}' to support
trimming these wild archive sizes can make situation better.
We already support retain_min && retain_days - but if user is
generating too many and too large archives with minutes - maybe archiving
should be disabled by a user - as it's not producing anything largely usable
and just slows-down command ??
If we add 'retain_max & retain_max_size' the condition will go against
each other and we need to chose priorities.
David Teigland [Tue, 28 Sep 2021 19:58:03 +0000 (14:58 -0500)]
handle bad metadata text in vg_read path
Corrupt metadata text (with good mda header) was being handled
in the label_scan phase, but not in the vg_read phase. This
was sufficient because metadata areas would always be read and
checksummed during label_scan (metadata parsing was skipped
previously as an optimization.)
Now, some metadata areas will not be read and checksummed
at all during the label_scan phase, only during the vg_read
phase. This means that bad metadata text may first be detected
in the vg_read phase. So, add equivalent bad metadata handling
to the vg_read path to match the label_scan path.
With larger metadata, decoding 'localtime()' for hinting time creation
of every LV may cause excessive check of /etc/localtime file.
Set TZ to ":/etc/localtime" so glibc reads this file just once
instead of check everytime if there has anything changed.
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.
When creating lvm2 metadata for VG, lvm2 allocate some buffer,
and if buffer is not big enough, the buffer is 'reallocated' bigger,
and whole metadata creation is repeated until metadata fits.
We can try to use 'previous' metadata size as hint to reduce looping
here.
Previous patch f853a1bc7afdebb44aeb8c1167e8784d155cad84 enabled
ima measurement unconditionally for every status call,
but it needs to be set only for 'dmsetup measure' command.
Useful when asking for UUID of each device where the list
could be now returned directly with NAME && UUID for each device.
Returning UUID is done in backward-compatible way. There's one unused
32-bit word value after the event number. This patch sets the bit
DM_NAME_LIST_FLAG_HAS_UUID if UUID is present and
DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID if it isn't (if none of these bits is
set, then we have an old kernel that doesn't support returning UUIDs). The
UUID is stored after this word. The 'next' value is updated to point after
the UUID, so that old version of libdevmapper will skip the UUID without
attempting to interpret it.
It's basically irrelavant which value we assing to optarg,
since it's set by getopt() function, but Coverity tool
is incorrectly reporting possibly dereference of NULL.
sysconf() may also return -1 although rather theoretically.
Default to 4K when such case would happen.
Also in function call it just once and keep as static variable.
Analyzer here was rather confused about possiblity of loosing previously
assigned device pointers - fixed by passing zero initialize memory
before first assign.
Ensure only nonNULL 'du' pointer is dereference altough the comment
to the last assign 'du' pointer already suggest 'NULL' case should not happen.
So just being explicit.
Adrian Ratiu [Thu, 9 Sep 2021 14:51:47 +0000 (17:51 +0300)]
man-generator: initialize struct stat to avoid MSAN error
When building lvm2 in Gentoo/ChromeOS with the ASAN memory
sanitizer enabled, man-generator fails with the following
error. Initializing makes the error go away.
* SUMMARY: MemorySanitizer: use-of-uninitialized-value /build/amd64-generic/tmp/portage/sys-fs/lvm2-2.02.187-r3/work/LVM2.2.02.187/tools/man-generator.c:3316:6 in _include_description_file
* Exiting
* ASAN error detected:
* ==2548047==WARNING: MemorySanitizer: use-of-uninitialized-value
* #0 0x558b00ab4730 in _include_description_file /build/amd64-generic/tmp/portage/sys-fs/lvm2-2.02.187-r3/work/LVM2.2.02.187/tools/man-generator.c:3316:6
* #1 0x558b00ab4730 in _print_man /build/amd64-generic/tmp/portage/sys-fs/lvm2-2.02.187-r3/work/LVM2.2.02.187/tools/man-generator.c:3426:21
* #2 0x558b00ab4730 in main /build/amd64-generic/tmp/portage/sys-fs/lvm2-2.02.187-r3/work/LVM2.2.02.187/tools/man-generator.c:3570:7
* #0 0x7fa9b2cbb807 in find_derivation /var/tmp/portage/cross-x86_64-cros-linux-gnu/glibc-2.33-r8/work/glibc-2.33/iconv/gconv_db.c:583:15
* #1 0x558b00a29559 in ?? ??:0
*
* Uninitialized value was created by an allocation of 'statbuf.i.i' in the stack frame of function 'main'
* #0 0x558b00ab1d4d in main /build/amd64-generic/tmp/portage/sys-fs/lvm2-2.02.187-r3/work/LVM2.2.02.187/tools/man-generator.c:3505