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>
Applications would need to know the uuid to manage the configurations
associated with the subvol and snapshots
Signed-off-by: Anand Jain <anand.jain@oracle.com>
The idea is that we usually use snapshot to backup/restore our data, and the
common way can be a cron script which makes lots of snapshots, so we can end
up with spending some time to find the latest snapshot to restore.
This adds a feature for 'btrfs subvolume list' to let it list snapshots by their
_created_ generation.
What we need to do is just to list them in descending order and get the latest
snapshot. What's more, we can find the oldest snapshot as well by listing
snapshots in ascending order.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Andrei Popa reported that there were two typos of default as dafault,
this patch fixes those two typos up.
Signed-off-by: Chris Samuel <chris@csamuel.org>
* mkfs.c (parse_size): ./mkfs.btrfs -A '' would read and possibly
write the byte before beginning of strdup'd heap buffer. All other
size-accepting options were similarly affected.
Reviewed-by: Josef Bacik <josef@redhat.com>
The new infrastructure offloads checking number of arguments passed to a
command to individual command handlers. Fix them up accordingly.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Separate every command group into its own file (cmds_<group>.c) and
rearrange includes. Remove btrfs_cmds.c.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Miao Xie