mirror of
git://sourceware.org/git/lvm2.git
synced 2025-03-11 20:58:50 +03:00
fa793bed64
Using "[ ]" operator together with "&&" (or ",") inside causes the
string list to be matched if and only if all the items given match
the value reported and the number of items also match. This is
strict list matching and the original behaviour we already have.
In contrast to that, the new "{ }" operator together with "&&" inside
causes the string list to be matched if and only if all the items given
match the value reported but the number of items don't need to match.
So we can provide a subset in selection criteria and if the subset
is found, it matches.
For example:
$ lvs -o name,tags
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
$ lvs -o name,tags -S 'tags=[a,b]'
LV LV Tags
lvol1 a,b
$ lvs -o name,tags -S 'tags={a,b}'
LV LV Tags
lvol1 a,b
lvol3 a,b,y
So in the example above the a,b is subset of a,b,y and therefore
it also matches.
Clearly, when using "||" (or "#") inside, the { } and [ ] is the
same:
$ lvs -o name,tags -S 'tags=[a#b]'
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
$ lvs -o name,tags -S 'tags={a#b}'
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
Also in addition to the above feature, fix list with single value
matching when using [ ]:
Before this patch:
$ lvs -o name,tags -S 'tags=[a]'
LV LV Tags
lvol0 a
lvol1 a,b
lvol3 a,b,y
With this patch applied:
$ lvs -o name,tags -S 'tags=[a]'
LV LV Tags
lvol0 a
In case neither [] or {} is used, assume {} (the behaviour is not
changed here):
$ lvs -o name,tags -S 'tags=a'
LV LV Tags
lvol0 a
lvol1 a,b
lvol3 a,b,y
So in new terms 'tags=a' is equal to 'tags={a}'.