btrfstune -s <dev> prints "Seeding flag is currently [un]set", based on whether or not BTRFS_SUPER_FLAG_SEEDING is enabled for the given device.
Signed-off-by: David Disseldorp <[email protected]> --- Documentation/btrfstune.asciidoc | 3 +++ btrfstune.c | 29 +++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/Documentation/btrfstune.asciidoc b/Documentation/btrfstune.asciidoc index 27100964..992da95d 100644 --- a/Documentation/btrfstune.asciidoc +++ b/Documentation/btrfstune.asciidoc @@ -30,6 +30,9 @@ Enable seeding on a given device. Value 1 will enable seeding, 0 will disable it A seeding filesystem is forced to be mounted read-only. A new device can be added to the filesystem and will capture all writes keeping the seeding device intact. +-s:: +Print whether or not seeding is enabled for a given device. + -r:: (since kernel: 3.7) + diff --git a/btrfstune.c b/btrfstune.c index 1e378ba1..603242b7 100644 --- a/btrfstune.c +++ b/btrfstune.c @@ -73,6 +73,15 @@ static int update_seeding_flag(struct btrfs_root *root, int set_flag) return ret; } +static void check_seeding_flag(struct btrfs_root *root) +{ + struct btrfs_super_block *disk_super = root->fs_info->super_copy; + u64 super_flags = btrfs_super_flags(disk_super); + + printf("Seeding flag is currently %sset\n", + (super_flags & BTRFS_SUPER_FLAG_SEEDING ? "" : "un")); +} + static int set_super_incompat_flags(struct btrfs_root *root, u64 flags) { struct btrfs_trans_handle *trans; @@ -374,6 +383,7 @@ static void print_usage(void) { printf("usage: btrfstune [options] device\n"); printf("\t-S value\tpositive value will enable seeding, zero to disable, negative is not allowed\n"); + printf("\t-s \t\tcheck whether seeding is enabled\n"); printf("\t-r \t\tenable extended inode refs\n"); printf("\t-x \t\tenable skinny metadata extent refs\n"); printf("\t-n \t\tenable no-holes feature (more efficient sparse file representation)\n"); @@ -390,6 +400,7 @@ int main(int argc, char *argv[]) int total = 0; int seeding_flag = 0; u64 seeding_value = 0; + int check_seeding = 0; int random_fsid = 0; char *new_fsid_str = NULL; int ret; @@ -401,7 +412,7 @@ int main(int argc, char *argv[]) { "help", no_argument, NULL, GETOPT_VAL_HELP}, { NULL, 0, NULL, 0 } }; - int c = getopt_long(argc, argv, "S:rxfuU:n", long_options, NULL); + int c = getopt_long(argc, argv, "S:srxfuU:n", long_options, NULL); if (c < 0) break; @@ -410,6 +421,9 @@ int main(int argc, char *argv[]) seeding_flag = 1; seeding_value = arg_strtou64(optarg); break; + case 's': + check_seeding = 1; + break; case 'r': super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF; break; @@ -448,7 +462,12 @@ int main(int argc, char *argv[]) error("random fsid can't be used with specified fsid"); return 1; } - if (!super_flags && !seeding_flag && !(random_fsid || new_fsid_str)) { + if (seeding_flag && check_seeding) { + error("check seeding can't be used alongside set seeding"); + return 1; + } + if (!super_flags && !seeding_flag && !check_seeding && + !(random_fsid || new_fsid_str)) { error("at least one option should be specified"); print_usage(); return 1; @@ -512,6 +531,12 @@ int main(int argc, char *argv[]) total++; } + if (check_seeding) { + check_seeding_flag(root); + success++; + total++; + } + if (super_flags) { ret = set_super_incompat_flags(root, super_flags); if (!ret) -- 2.13.7
