btrfs-progs: btrfstune: force to set seeding flags

Now we can use -f with -S option when setting seeding flags or clearing
seeding flags

Reported-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Signed-off-by: Fan Chengniang <fancn.fnst@cn.fujitsu.com>
[updated docs]
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/Documentation/btrfstune.txt b/Documentation/btrfstune.txt
index d49a974..9620221 100644 (file)
--- a/Documentation/btrfstune.txt
+++ b/Documentation/btrfstune.txt
@@ -25,7 +25,8 @@ Enable extended inode refs.
 -x::
 Enable skinny metadata extent refs.
 -f::
-Allow dangerous changes, e.g. clear the seeding flag
+Allow dangerous changes, e.g. clear the seeding flag. Make sure that you are
+aware of the dangers.
 
 When mounting the new device, btrfs will check whether the seeding flag is set
 when try to open seeding device.  If the user clears the seeding flag of the

diff --git a/btrfstune.c b/btrfstune.c
index cba00a8..075fbc6 100644 (file)
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -33,6 +33,7 @@
 #include "version.h"
 
 static char *device;
+static int force = 0;
 
 static int update_seeding_flag(struct btrfs_root *root, int set_flag)
 {
@@ -44,8 +45,10 @@ static int update_seeding_flag(struct btrfs_root *root, int set_flag)
        super_flags = btrfs_super_flags(disk_super);
        if (set_flag) {
                if (super_flags & BTRFS_SUPER_FLAG_SEEDING) {
-                       fprintf(stderr, "seeding flag is already set on %s\n",
-                               device);
+                       if (force)
+                               return 0;
+                       else
+                               fprintf(stderr, "seeding flag is already set on %s\n", device);
                        return 1;
                }
                super_flags |= BTRFS_SUPER_FLAG_SEEDING;
@@ -104,7 +107,7 @@ static void print_usage(void)
        fprintf(stderr, "\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n");
        fprintf(stderr, "\t-r \t\tenable extended inode refs\n");
        fprintf(stderr, "\t-x \t\tenable skinny metadata extent refs\n");
-       fprintf(stderr, "\t-f \t\tforce to clear flags, make sure that you are aware of the dangers\n");
+       fprintf(stderr, "\t-f \t\tforce to set or clear flags, make sure that you are aware of the dangers\n");
 }
 
 int main(int argc, char *argv[])
@@ -116,7 +119,6 @@ int main(int argc, char *argv[])
        int seeding_flag = 0;
        u64 seeding_value = 0;
        int skinny_flag = 0;
-       int force = 0;
        int ret;
 
        optind = 1;