From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:26672 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751067AbaENHfJ (ORCPT ); Wed, 14 May 2014 03:35:09 -0400 Message-ID: <53731BE3.5010604@cn.fujitsu.com> Date: Wed, 14 May 2014 15:31:47 +0800 From: Wang Shilong MIME-Version: 1.0 To: Eric Sandeen CC: linux-btrfs , Subject: Re: [PATCH] mkfs.btrfs: allow UUID specification at mkfs time References: <5372C457.3000706@redhat.com> In-Reply-To: <5372C457.3000706@redhat.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 05/14/2014 09:18 AM, Eric Sandeen wrote: > Allow the specification of the filesystem UUID at mkfs time. > > (Implemented only for mkfs.btrfs, not btrfs-convert). Just out of curiosity, this option is used for what kind of use case? I notice Ext4 also has this option.:-) > > Signed-off-by: Eric Sandeen > --- > > diff --git a/btrfs-convert.c b/btrfs-convert.c > index a8b2c51..d62d4f8 100644 > --- a/btrfs-convert.c > +++ b/btrfs-convert.c > @@ -2240,7 +2240,7 @@ static int do_convert(const char *devname, int datacsum, int packing, > goto fail; > } > ret = make_btrfs(fd, devname, ext2_fs->super->s_volume_name, > - blocks, total_bytes, blocksize, blocksize, > + NULL, blocks, total_bytes, blocksize, blocksize, > blocksize, blocksize, 0); > if (ret) { > fprintf(stderr, "unable to create initial ctree: %s\n", > diff --git a/man/mkfs.btrfs.8.in b/man/mkfs.btrfs.8.in > index bef509d..4450d03 100644 > --- a/man/mkfs.btrfs.8.in > +++ b/man/mkfs.btrfs.8.in > @@ -16,6 +16,7 @@ mkfs.btrfs \- create a btrfs filesystem > [ \fB\-r\fP\fI rootdir\fP ] > [ \fB\-K\fP ] > [ \fB\-O\fP\fI feature1,feature2,...\fP ] > +[ \fB\-U\fP\fI uuid\fP ] > [ \fB\-h\fP ] > [ \fB\-V\fP ] > \fI device\fP [ \fIdevice ...\fP ] > @@ -90,6 +91,9 @@ To see all run > > \fBmkfs.btrfs -O list-all\fR > .TP > +\fB\-U\fR, \fB\-\-uuid \fR > +Create the filesystem with the specified UUID. > +.TP > \fB\-V\fR, \fB\-\-version\fR > Print the \fBmkfs.btrfs\fP version and exit. > .SH UNIT > diff --git a/mkfs.c b/mkfs.c > index dbd83f5..eccb08f 100644 > --- a/mkfs.c > +++ b/mkfs.c > @@ -288,6 +288,7 @@ static void print_usage(void) > fprintf(stderr, "\t -r --rootdir the source directory\n"); > fprintf(stderr, "\t -K --nodiscard do not perform whole device TRIM\n"); > fprintf(stderr, "\t -O --features comma separated list of filesystem features\n"); > + fprintf(stderr, "\t -U --uuid specify the filesystem UUID\n"); > fprintf(stderr, "\t -V --version print the mkfs.btrfs version and exit\n"); > fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION); > exit(1); > @@ -351,6 +352,7 @@ static struct option long_options[] = { > { "rootdir", 1, NULL, 'r' }, > { "nodiscard", 0, NULL, 'K' }, > { "features", 0, NULL, 'O' }, > + { "uuid", 0, NULL, 'U' }, > { NULL, 0, NULL, 0} > }; > > @@ -1273,11 +1275,12 @@ int main(int ac, char **av) > int dev_cnt = 0; > int saved_optind; > char estr[100]; > + char *fs_uuid = NULL; > u64 features = DEFAULT_MKFS_FEATURES; > > while(1) { > int c; > - c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:O:r:VMK", > + c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:O:r:U:VMK", > long_options, &option_index); > if (c < 0) > break; > @@ -1346,6 +1349,9 @@ int main(int ac, char **av) > source_dir = optarg; > source_dir_set = 1; > break; > + case 'U': > + fs_uuid = optarg; > + break; > case 'K': > discard = 0; > break; > @@ -1514,7 +1520,7 @@ int main(int ac, char **av) > > process_fs_features(features); > > - ret = make_btrfs(fd, file, label, blocks, dev_block_count, > + ret = make_btrfs(fd, file, label, fs_uuid, blocks, dev_block_count, > nodesize, leafsize, > sectorsize, stripesize, features); > if (ret) { > diff --git a/utils.c b/utils.c > index 3e9c527..3f46e8f 100644 > --- a/utils.c > +++ b/utils.c > @@ -93,12 +93,12 @@ static u64 reference_root_table[] = { > [6] = BTRFS_CSUM_TREE_OBJECTID, > }; > > -int make_btrfs(int fd, const char *device, const char *label, > +int make_btrfs(int fd, const char *device, const char *label, char *fs_uuid, > u64 blocks[7], u64 num_bytes, u32 nodesize, > u32 leafsize, u32 sectorsize, u32 stripesize, u64 features) > { > struct btrfs_super_block super; > - struct extent_buffer *buf; > + struct extent_buffer *buf = NULL; > struct btrfs_root_item root_item; > struct btrfs_disk_key disk_key; > struct btrfs_extent_item *extent_item; > @@ -125,7 +125,14 @@ int make_btrfs(int fd, const char *device, const char *label, > memset(&super, 0, sizeof(super)); > > num_bytes = (num_bytes / sectorsize) * sectorsize; > - uuid_generate(super.fsid); > + if (fs_uuid) { > + if (uuid_parse(fs_uuid, super.fsid) != 0) { > + fprintf(stderr, "could not parse UUID: %s\n", fs_uuid); > + ret = -EINVAL; > + goto out; > + } > + } else > + uuid_generate(super.fsid); > uuid_generate(super.dev_item.uuid); > uuid_generate(chunk_tree_uuid); > > diff --git a/utils.h b/utils.h > index 3c62066..054cbb6 100644 > --- a/utils.h > +++ b/utils.h > @@ -40,7 +40,7 @@ > #define BTRFS_UUID_UNPARSED_SIZE 37 > > int make_btrfs(int fd, const char *device, const char *label, > - u64 blocks[6], u64 num_bytes, u32 nodesize, > + char *fs_uuid, u64 blocks[6], u64 num_bytes, u32 nodesize, > u32 leafsize, u32 sectorsize, u32 stripesize, u64 features); > int btrfs_make_root_dir(struct btrfs_trans_handle *trans, > struct btrfs_root *root, u64 objectid); > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > . >