Dave Wysochanski [Mon, 25 Oct 2010 14:09:08 +0000 (14:09 +0000)]
Add lvm_lv_get_property() generic function to obtain value of any lv propert
Add a generic LV property function to lvm2app, similar to VG function.
Return lvm_property_value and require caller to check 'is_valid' flag
and lvm_errno() for API error.
Dave Wysochanski [Mon, 25 Oct 2010 14:08:55 +0000 (14:08 +0000)]
Add lvm_pv_get_property() generic function to obtain value of any pv property.
Add a generic PV property function to lvm2app, similar to VG function.
Return lvm_property_value and require caller to check 'is_valid' flag
before using the value. If 'is_valid' is not set, then lvm_errno()
should be used to obtain the specific error.
Add a generic VG property function to lvm2app. Call the internal library
vg_get_property() function. Strings are dup'd internally.
Rework lvm_vg_get_property to return lvm_property_value and require caller
to check 'is_valid' flag. If !is_valid, the caller can check lvm_errno()
for the specific error.
Create a 'get_property' function, local to lvm2app, that factors out
most of the common code that copies the components of lvm_property_type
into lvm_property_value. This allows for a 1-line function for each
of the generic property functions exported by lvm2app.
Zdenek Kabelac [Mon, 25 Oct 2010 12:57:00 +0000 (12:57 +0000)]
Fix potential NULL pointer dereference
Makes clang happier as it covers all code paths and avoids NULL pointer
dereference through the 'com' pointer (which is NULL by default static
initialisation).
Zdenek Kabelac [Mon, 25 Oct 2010 11:57:06 +0000 (11:57 +0000)]
Fix clang warning for ntohl(*((uint32_t *)buf))
We cast (char*) to (uint32_t*) that changes alignment requierements.
For our case the code has been correct as alloca() returns properly
aligned buffer, however this patch make it cleaner and more readable
and avoids warning generation.
Mike Snitzer [Sun, 24 Oct 2010 17:36:58 +0000 (17:36 +0000)]
Never scan a device which is using the error target
A merged snapshot's DM device is made to use the "error" target as part
of lvm's transaction to merge a snapshot. This snapshot merge use-case
aside, any device using the error target shouldn't be scanned.
Dave Wysochanski [Thu, 21 Oct 2010 14:49:43 +0000 (14:49 +0000)]
Rename fields in lvm_property_type.
Based on review comments, rename a few fields in lvm_property_type.
In particular, change 'is_writeable' to 'is_settable', which is
more intuitive to the intent of the bitfield (a 'set' function
exists for this field/property). Also, remove the char array
for 'id' - unnecessary as we can just use the string passed in
to do the strcmp. Finally rename the union members from n_val
to 'integer' and 's_val' to 'string'.
Petr Rockai [Wed, 20 Oct 2010 14:46:45 +0000 (14:46 +0000)]
Fix a deadlock in clvmd.
The signalling code (pthread_cond_signal/pthread_cond_wait) in the
pre_and_post_thread was using the wait mutex (see man pthread_cond_wait)
incorrectly, and this could cause clvmd to deadlock when timing was
right. Detailed explanation of the problem follows.
There is a single mutex around (L for Lock, U for Unlock), a signal (S) and a
wait (W). C for pthread_create. Time flows from left to right, each arrow is a
thread.
So first the "naive" scenario, with no mutex (PPT = pre_and_post_thread, MCT =
main clvmd thread; well actually the thread that does read_from_local_sock). I
will also use X, for a moment when MCT actually waits for something to happen
that PPT was supposed to do.
MCT -----C ------S--X-----S----X----------------------S------XXXXXXXXX
| everything OK up to this --> <-- point...
PPT -----WWW-----WWWW------------------------------WWWWWWWWWWWWW
Ok, so pthread API actually does not let you use W/S like that. It goes out of
its way to tell you that you need a mutex to protect the W so that the above
cannot happen. *But* if you are creative and just lock around the W's and S's,
this happens:
Ooops. Nothing changed (the above is what actually was done by clvmd before
this satch). So let's do it differently, holding L locked *all* the time in
PPT, unless we are actually in W (this is something that the pthread API does
itself, see the man page).
MCT ----C-----LSU------X---LSU---X-----LLLLLLLSU----X----
| (and they live happily ever after)
PPT L---WWWWW---------WWWW----------------W----------
So W actually ensures that L is unlocked *atomically* together with entering
the wait. That means that unless PPT is actually waiting, it cannot be
signalled by MCT. So if MCT happens to signal it too soon (it wasn't waiting
yet), it (MCT) will be blocked on the mutex (L), until PPT is actually ready to
do something.
Petr Rockai [Fri, 15 Oct 2010 16:28:14 +0000 (16:28 +0000)]
Implement automatic snapshot extension with dmeventd, and add two new options
to lvm.conf in the activation section: 'snapshot_autoextend_threshold' and
'snapshot_autoextend_percent', that define how to handle automatic snapshot
extension. The former defines when the snapshot should be extended: when its
space usage exceeds this many percent. The latter defines how much extra space
should be allocated for the snapshot, in percent of its current size.
Fix for bug 637936: killing both redundant logs causes deadlock
Problem:
When both legs of a mirrored log fail, neither the log nor the parent
mirror can proceed. The repair code must be careful to replace the
log with an error target before operating on the parent - otherwise,
the parent can get stuck trying to suspend because it can't push through
any writes. The steps to replace the log device with an error target
were incomplete and resulted in the replacement not happening at all!
The code originally had all the necessary logic to complete the
replacement task, but was pulled out in a effort to clean-up that
section of code, while fixing another bug:
<offending commit msg>
In addition, I added following three changes.
- Removed tmp_orphan_lvs handling procedure
It seems that _delete_lv() can handle detached_log_lv properly
without adding mirror legs in mirrored log to tmp_orphan_lvs.
Therefore, I removed the procedure.
- Removed vg_write()/vg_commit()
Metadata is saved by vg_write()/vg_commit() just after detached_log_lv
is handled. Therefore, I removed vg_write()/vg_commit().
</offending commit msg>
Mike Snitzer [Wed, 13 Oct 2010 21:26:37 +0000 (21:26 +0000)]
Convey need for snapshot-merge target in lvconvert error message and man
page.
Add ->target_name to segtype_handler to allow a more specific target
name to be returned based on the state of the segment.
Result of trying to merge a snapshot using a kernel that doesn't have
the snapshot-merge target:
Before:
# lvconvert --merge vg/snap
Can't expand LV lv: snapshot target support missing from kernel?
Failed to suspend origin lv
After:
# lvconvert --merge vg/snap
Can't process LV lv: snapshot-merge target support missing from kernel?
Failed to suspend origin lv
Unable to merge LV "snap" into it's origin.
Zdenek Kabelac [Wed, 13 Oct 2010 12:18:53 +0000 (12:18 +0000)]
Don't use floor() in _bitset_with_random_bits
Use _even_rand() function instead of floor() in _bitset_with_random_bits().
floor() function is missing in dietlibc (on architectures other than x86).
Moreover using floor() to clip rand results does not assure even result
distribution. _even_rand() uses integer arithmetic only and is designed to
return evenly distributed results.
> Looks OK to me. It took a while to decipher what is the exact meaning of
> the loop in _even_rand (to a non-pseudorandomness-expert) but I am
> fairly comfortable with it now. If I understand this correctly, it
> rejects numbers that come from an "incomplete" slice of the RAND_MAX
> space (considering the number space [0, RAND_MAX] is divided into some
> "max"-sized slices and at most a single smaller slice, between [n*max,
> RAND_MAX] for suitable n -- numbers from this last slice are discarded
> because they could distort the distribution in favour of smaller
> numbers).
Petr Rockai [Wed, 13 Oct 2010 10:34:31 +0000 (10:34 +0000)]
Implement vgextend --restoremissing (BZ 537913), which makes it possible to
re-add a physical volume that has gone missing previously, due to a transient
device failure, without re-initialising it.
Signed-off-by: Petr Rockai <prockai@redhat.com> Reviewed-by: Alasdair Kergon <agk@redhat.com>
Zdenek Kabelac [Fri, 8 Oct 2010 15:02:05 +0000 (15:02 +0000)]
Add support for noninterctive shell execution
Try to distinguish between the case of using interactive shell and non
interactive running - different combinations of '-y' and '-p' option
needs to be used for fsck.
Zdenek Kabelac [Fri, 8 Oct 2010 14:55:19 +0000 (14:55 +0000)]
Fix detection of mounted filesystem.
Update the way how fsadm detects mounted filesystem.
With udev /dev/dm-XXX paths are now returned - but mount or /proc/mounts
prints names in form of /dev/mapper/vg-lv - so the match was not found.
Fixex RHBZ #638050.
Current solution uses same trick as mount and detects vg-lv name through
/sys where available - this should be reasonable safe.
Instead of calling mount without parameter to get actual mount table,
switch to use /proc/mounts directly.
Zdenek Kabelac [Fri, 8 Oct 2010 12:35:56 +0000 (12:35 +0000)]
Fix a serious bug in the behavior of fasdm tool when breaked.
Under certain conditions it was possible to break (^C) fsadm before actually
resizing filesystem, but lvresize which executed fsadm will think resize
was succesful and shrinks partitions with unresized filesystem on it.
Fix by returning error (1) for this case - this stops lvresize from futher
proceding in resize operation.
Rename 'flags' to 'status' for struct metadata_area.
In other LVM memory structures such as volume_group, the field
used to store flags is called "status", and on-disk fields are called
'flags', so rename the one inside metadata_area to be consistent.
Not only is it more consistent with existing code but is cleaner
to say "the status of this mda is ignored".
Background for this patch - prajnoha pinged me on IRC this morning
about a fix he was working on related to metadataignore when
metadata/dirs was set. I was reviewing my patches from this year
and realized the 'flags' field was probably not the best choice
when I originally did the metadataignore patches.