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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00
lvm2/libdm
Peter Rajnoha 82f6dbfaf7 select: fix matching reserved values while <,<=,>,>= is used in selection criteria
Scenario:

$ vgs -o+vg_mda_copies
  VG     #PV #LV #SN Attr   VSize VFree #VMdaCps
  fedora   1   2   0 wz--n- 9.51g    0  unmanaged
  vg      16   9   0 wz--n- 1.94g 1.83g         2

$ lvs -o+read_ahead vg/lvol6 vg/lvol7
  LV    VG   Attr       LSize Pool Origin Data%  Rahead
  lvol6 vg   Vwi-a-tz-- 1.00g pool lvol5  0.00      auto
  lvol7 vg   Vwi---tz-k 1.00g pool lvol6         256.00k

Before this patch:

$vgs -o vg_name,vg_mda_copies -S 'vg_mda_copies < unmanaged'
  VG   #VMdaCps
  vg          2

Problem:
Reserved values can be only used with exact match = or !=, not <,<=,>,>=.
In the example above, the "unamanaged" is internally represented as
18446744073709551615, but this should be ignored while not comparing
field directly with "unmanaged" reserved name with = or !=. Users
should not be aware of this internal mapping of the reserved value
name to its internal value and hence it doesn't make sense for such
reserved value to take place in results of <,<=,> and >=.
There's no order defined for reserved values!!! It's a special
*reserved* value that is taken out of the usual value range
of that type.

This is very similar to what we have already fixed with
2f7f6932dc, but it's the other way round
now - we're using reserved value name in selection criteria now
(in the patch 2f7f693, we had concrete value and we compared it
with the reserved value). So this patch completes patch 2f7f693.

This patch also fixes this problem:

$ lvs -o+read_ahead vg/lvol6 vg/lvol7 -S 'read_ahead > 32k'
  LV    VG   Attr       LSize Pool Origin Data%  Rahead
  lvol6 vg   Vwi-a-tz-- 1.00g pool lvol5  0.00      auto
  lvol7 vg   Vwi---tz-k 1.00g pool lvol6         256.00k

Problem:
In the example above, the internal reserved value "auto" is in the
range of selection "> 32k" - it shouldn't match as well. Here the
"auto" is internally represented as MAX_DBL and of course, numerically,
MAX_DBL > 256k. But for users, the reserved value should be uncomparable
to any number so the mapping of the reserved value name to its interna
 value is transparent to users. Again, there's no order defined for
reserved values and hence it should never match if using <,<=,>,>=
operators.

This is actually exactly the same problem as already described in
2f7f6932dc, but that patch failed for
size field types because of incorrect internal representation used.

With this patch applied, both problematic scenarios mentioned
above are fixed now:

$ vgs -o vg_name,vg_mda_copies -S 'vg_mda_copies < unmanaged'
(blank)

$ lvs -o+read_ahead vg/lvol6 vg/lvol7 -S 'read_ahead > 32k'
  LV    VG   Attr       LSize Pool Origin Rahead
  lvol7 vg   Vwi---tz-k 1.00g pool lvol6  256.00k
2015-04-24 09:48:57 +02:00
..
datastruct Use void pointer instead of char for binary key 2011-03-10 12:48:40 +00:00
ioctl libdm: Add uuid/devno to ioctl failure log message. 2015-04-23 19:26:52 +01:00
misc libdm: Add DM_INTERNAL_SUSPEND_FLAG. 2015-04-23 18:39:04 +01:00
mm cleanup: indents comments backtraces 2014-11-10 22:05:49 +01:00
regex cleanup: add braces for if() 2014-07-02 10:45:43 +02:00
.exported_symbols dmsetup: Support remove --deferred. 2014-08-16 00:34:48 +01:00
libdevmapper.h libdm: report: add dm_report_object_is_selected 2015-02-10 16:04:38 +01:00
libdevmapper.pc.in Switch to use Requires.private for devmapper.pc and lvm2app.pc 2010-05-11 08:54:11 +00:00
libdm-common.c libdm: revert incorrect path length size for sscanf 2014-08-29 13:10:18 +02:00
libdm-common.h libdm: introduce and use DEV_UUID macro 2012-10-10 17:16:15 +02:00
libdm-config.c cleanup: drop unused value assign 2015-02-19 14:43:25 +01:00
libdm-deptree.c thin: errrorwhenfull support 2015-01-14 14:52:05 +01:00
libdm-file.c Drop unreachable code 2012-02-08 12:59:45 +00:00
libdm-report.c select: fix matching reserved values while <,<=,>,>= is used in selection criteria 2015-04-24 09:48:57 +02:00
libdm-string.c cleanup: libdm simplier error comparation 2014-07-02 10:45:42 +02:00
Makefile.in configure: Look for valgrind.h independently of VALGRIND_POOLS. 2015-02-05 13:50:34 +01:00