This patch introduces '-g' '-c' '--sort' options
The option '-g' can help you filter the subvolumes by the generation, you may
use it just like:
btrfs subvol list -g +/-value <path>
'+' means the generation of the subvolumes should >= the value you specified.
'-' means the generation should <= the value
If you don't input either '+' nor '-', this command will list the subvolumes
that their generation equals to the value.
However if you want to find gengeration between value1 and value2
you may use the above like:
btrfs sub list -g -value1 -g +value2 <path>
The option '-c' can help you filter the subvolumes by the ogeneration, you may
use it just like:
btrfs subvol list -c +/-value <path>
The usage is the same to '-g'
You might want to list subvolumes in order of some items, such as root id, gen
and so on, you can use '--sort'. Now you can sort the subvolumes by root id,
gen, ogen and path.
For example:
If you want to list subvolumes in order of rootid, you can use the option like
that:
btrfs sub list --sort=+/-rooid <path>
Here, '+' means the result is sorted by ascending order. '-' is by descending
order. If you don't specify either '+' nor '-', the result is sorted by
default - ascending order.
If you want to combine sort items, you do it like that:
btrfs sub list --sort=-rootid,+path,ogen,gen <path>
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
We want 'btrfs subvolume list' only to list readonly subvolumes, this patch set
introduces a new option 'r' to implement it.
You can use the command like that:
btrfs subvolume list -r <path>
Original-Signed-off-by: Zhou Bo <zhoub-fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
The current code of list_subvols() has very bad scalability, if we want to
add new filter conditions or new sort methods, we have to modify lots of code.
Beside that, the most code of list_snapshots() is similar to list_subvols(),
So I restructure list_subvols(), and split the subvolume filter function,
the subvolume sort function and the output function from list_subvols().
In order to implement it, we defined some importtant structures:
struct btrfs_list_filter {
btrfs_list_filter_func filter_func;
void *data;
};
struct btrfs_list_comparer {
btrfs_list_comp_func comp_func;
int is_descending;
};
struct {
char *name;
char *column_name;
int need_print;
} btrfs_list_columns[];
If we want to add a new filter condition, we can choose a suitable filter
function, or implement a new filter function[1], and add it into a set of
the filters, and then pass the filter set into list_subvols(). We also can
mix several filters (just add those filters into the set, and pass the set
into list_subvols()) if the users specify two or more filter conditions.
The subvolume sort function is similar to the subvolume filter function. The
differentiation is the order of comparers in the array which is passed into
list_subvols() show us the priority of the sort methods.
The output function is different with the above two functions, we define a
array to manage all the columns that can be outputed, and use a member variant
(->need_print) to control the output of the relative column. Some columns are
outputed by default. But we can change it according to the requirement of the
users.
After appling this patch, we needn't implement a independent list_snapshots()
function, just pass a filter function which is used to identify the snapshot
into list_subvols().
[1]: If we implement new filter functions or compare functions, we must add
them into the array all_filter_funcs or the array all_comp_funcs, and modify
the relative enum variants(btrfs_list_filter_enum, btrfs_list_comp_enum).
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
This patch fixes the following warning:
cmds-subvolume.c:283:3: warning: implicit declaration of function "list_snapshots"
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
wangshilong