restore: Add regex matching of paths and files to be restored

The option -m is used to specify the regex string. -c is used to
specify case insensitive matching. -i was already taken.

In order to restore only a single folder somewhere in the btrfs
tree, it is unfortunately neccessary to construct a slightly
nontrivial regex, e.g.:

restore -m '^/(|home(|/username(|/Desktop(|/.*))))$' /dev/sdb2 /output

This is needed in order to match each directory along the way to the
Desktop directory, as well as all contents below the Desktop directory.

Signed-off-by: Peter Stuge <peter@stuge.se>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/cmds-restore.c b/cmds-restore.c
index e48df40..1aae390 100644 (file)
--- a/cmds-restore.c
+++ b/cmds-restore.c
@@ -27,9 +27,11 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <lzo/lzoconf.h>
 #include <lzo/lzo1x.h>
 #include <zlib.h>
+#include <regex.h>
 
 #include "ctree.h"
 #include "disk-io.h"
@@ -539,7 +541,8 @@ set_size:
 }
 
 static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
-                     const char *output_rootdir, const char *dir)
+                     const char *output_rootdir, const char *dir,
+                     const regex_t *mreg)
 {
        struct btrfs_path *path;
        struct extent_buffer *leaf;
@@ -646,6 +649,9 @@ static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
                /* full path from root of btrfs being restored */
                snprintf(fs_name, 4096, "%s/%s", dir, filename);
 
+               if (REG_NOMATCH == regexec(mreg, fs_name, 0, NULL, 0))
+                       goto next;
+
                /* full path from system root */
                snprintf(path_name, 4096, "%s%s", output_rootdir, fs_name);
 
@@ -759,7 +765,7 @@ static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
                        }
                        loops = 0;
                        ret = search_dir(search_root, &location,
-                                        output_rootdir, dir);
+                                        output_rootdir, dir, mreg);
                        free(dir);
                        if (ret) {
                                if (ignore_errors)
@@ -990,8 +996,13 @@ int cmd_restore(int argc, char **argv)
        int super_mirror = 0;
        int find_dir = 0;
        int list_roots = 0;
+       const char *match_regstr = NULL;
+       int match_cflags = REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
+       regex_t match_reg, *mreg = NULL;
+       char reg_err[256];
+
+       while ((opt = getopt(argc, argv, "sviot:u:df:r:lcm:")) != -1) {
 
-       while ((opt = getopt(argc, argv, "sviot:u:df:r:l")) != -1) {
                switch (opt) {
                        case 's':
                                get_snaps = 1;
@@ -1045,6 +1056,12 @@ int cmd_restore(int argc, char **argv)
                        case 'l':
                                list_roots = 1;
                                break;
+                       case 'c':
+                               match_cflags |= REG_ICASE;
+                               break;
+                       case 'm':
+                               match_regstr = optarg;
+                               break;
                        default:
                                usage(cmd_restore_usage);
                }
@@ -1116,9 +1133,21 @@ int cmd_restore(int argc, char **argv)
                key.objectid = BTRFS_FIRST_FREE_OBJECTID;
        }
 
-       ret = search_dir(root, &key, dir_name, "");
+       if (match_regstr) {
+               ret = regcomp(&match_reg, match_regstr, match_cflags);
+               if (ret) {
+                       regerror(ret, &match_reg, reg_err, sizeof(reg_err));
+                       fprintf(stderr, "Regex compile failed: %s\n", reg_err);
+                       goto out;
+               }
+               mreg = &match_reg;
+       }
+
+       ret = search_dir(root, &key, dir_name, "", mreg);
 
 out:
+       if (mreg)
+               regfree(mreg);
        close_ctree(root);
        return ret;
 }