493dfc9d1f
This allows us to change the use-visible UUID on filesytems from userspace if desired, by copying the existing UUID to the new location for metadata comparisons. If this is done, an incompat flag must be set to prevent older filesystems from mounting the filesystem, but the original UUID can be restored, and the incompat flag removed. This introduces the new -m|-M UUID options similar to current -u|-U UUID ones with the difference that we don't rewrite the fsid but just copy the old uuid and set a new one. Additionally running with [-M old-uuid] clears the incompat flag and retains only fsid on-disk. Additionally it's not allowed to intermix -m/-u/-U/-M options in a single invocation of btrfstune, nor is it allowed to change the uuid while there is a uuid rewrite in-progress. Also changing the uuid of a seed device is not currently allowed (can change in the future). Example: btrfstune -m /dev/loop1 btrfs inspect-internal dump-super /dev/loop1 superblock: bytenr=65536, device=/dev/loop1 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x4b7ea749 [match] <ommitted for brevity> fsid 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 metadata_uuid 352715e7-62cf-4ae0-92ee-85a574adc318 <ommitted for brevity> incompat_flags 0x541 ( MIXED_BACKREF | EXTENDED_IREF | SKINNY_METADATA | METADATA_UUID ) <omitted for brevity> dev_item.uuid 0610deee-dfc3-498b-9449-a06533cdec98 dev_item.fsid 352715e7-62cf-4ae0-92ee-85a574adc318 [match] <ommitted for brevity> mount /dev/loop1 btrfs-mnt/ btrfs fi show btrfs-mnt/ Label: none uuid: 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8 Total devices 1 FS bytes used 128.00KiB devid 1 size 5.00GiB used 536.00MiB path /dev/loop1 In this case a new btrfs filesystem was created and the original uuid was 352715e7-62cf-4ae0-92ee-85a574adc318, then btrfstune was run which copied that value over to metadata_uuid field and set the current fsid to 0efc41d3-4451-49f3-8108-7b8bdbcf5ae8. And as far as userspace is concerned this is the fsid of the fs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
---|---|---|
Documentation | ||
check | ||
convert | ||
image | ||
kernel-lib | ||
kernel-shared | ||
libbtrfsutil | ||
m4 | ||
mkfs | ||
tests | ||
travis | ||
.gitignore | ||
.travis.yml | ||
64-btrfs-dm.rules | ||
Android.mk | ||
CHANGES | ||
COPYING | ||
INSTALL | ||
Makefile | ||
Makefile.extrawarn | ||
Makefile.inc.in | ||
README.md | ||
VERSION | ||
androidcompat.h | ||
autogen.sh | ||
backref.c | ||
backref.h | ||
bcp | ||
btrfs-completion | ||
btrfs-corrupt-block.c | ||
btrfs-crc.c | ||
btrfs-debugfs | ||
btrfs-find-root.c | ||
btrfs-fragments.c | ||
btrfs-list.c | ||
btrfs-list.h | ||
btrfs-map-logical.c | ||
btrfs-sb-mod.c | ||
btrfs-select-super.c | ||
btrfs.c | ||
btrfsck.h | ||
btrfstune.c | ||
chunk-recover.c | ||
cmds-balance.c | ||
cmds-device.c | ||
cmds-fi-du.c | ||
cmds-fi-usage.c | ||
cmds-fi-usage.h | ||
cmds-filesystem.c | ||
cmds-inspect-dump-super.c | ||
cmds-inspect-dump-tree.c | ||
cmds-inspect-tree-stats.c | ||
cmds-inspect.c | ||
cmds-property.c | ||
cmds-qgroup.c | ||
cmds-quota.c | ||
cmds-receive.c | ||
cmds-replace.c | ||
cmds-rescue.c | ||
cmds-restore.c | ||
cmds-scrub.c | ||
cmds-send.c | ||
cmds-subvolume.c | ||
commands.h | ||
common-defs.h | ||
configure.ac | ||
ctree.c | ||
ctree.h | ||
delayed-ref.c | ||
delayed-ref.h | ||
dir-item.c | ||
disk-io.c | ||
disk-io.h | ||
extent-cache.c | ||
extent-cache.h | ||
extent-tree.c | ||
extent_io.c | ||
extent_io.h | ||
file-item.c | ||
file.c | ||
find-root.c | ||
find-root.h | ||
free-space-cache.c | ||
free-space-cache.h | ||
free-space-tree.c | ||
free-space-tree.h | ||
fsck.btrfs | ||
fsfeatures.c | ||
fsfeatures.h | ||
hash.h | ||
hasher.c | ||
help.c | ||
help.h | ||
inode-item.c | ||
inode-map.c | ||
inode.c | ||
internal.h | ||
ioctl-test.c | ||
ioctl.h | ||
kerncompat.h | ||
library-test.c | ||
messages.c | ||
messages.h | ||
print-tree.c | ||
print-tree.h | ||
props.c | ||
props.h | ||
qgroup-verify.c | ||
qgroup-verify.h | ||
qgroup.c | ||
qgroup.h | ||
quick-test.c | ||
random-test.c | ||
rbtree-utils.c | ||
rbtree-utils.h | ||
repair.c | ||
repair.h | ||
root-tree.c | ||
send-dump.c | ||
send-dump.h | ||
send-stream.c | ||
send-stream.h | ||
send-utils.c | ||
send-utils.h | ||
send.h | ||
show-blocks | ||
string-table.c | ||
string-table.h | ||
super-recover.c | ||
task-utils.c | ||
task-utils.h | ||
transaction.c | ||
transaction.h | ||
utils-lib.c | ||
utils.c | ||
utils.h | ||
uuid-tree.c | ||
version.h.in | ||
volumes.c | ||
volumes.h |
README.md
Btrfs-progs
Userspace utilities to manage btrfs filesystems. License: GPLv2.
Btrfs is a copy on write (COW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration.
This repository hosts following utilities:
- btrfs — the main administration tool (manual page)
- mkfs.btrfs — utility to create the filesystem (manual page)
The C and python 3 bindings are provided by a LGPL library libbtrfsutil see libbtrfsutil/README.md for more.
See INSTALL for build instructions and tests/README.md for testing information.
Release cycle
The major version releases are time-based and follow the cycle of the linux kernel releases. The cycle usually takes 2 months. A minor version releases may happen in the meantime if there are bug fixes or minor useful improvements queued.
The release tags are signed with a GPG key ID F2B4 1200 C54E FB30 380C 1756 C565 D5F9 D76D 583B
,
release tarballs are hosted at kernel.org.
See file CHANGES or changelogs on wiki.
Reporting bugs
There are several ways, each has its own specifics and audience that can give feedback or work on a fix. The following list is sorted in the order of preference:
- github issue tracker
- to the mailing list linux-btrfs@vger.kernel.org -- (not required to subscribe), beware that the mail might get overlooked in other traffic
- IRC (irc.freenode.net #btrfs) -- good for discussions eg. if a bug is already known, but reports could miss developers' attention
- bugzilla.kernel.org -- (requires registration), set the product to Filesystems and component Btrfs, please put 'btrfs-progs' into the subject so it's clear that it's not a kernel bug report
Development
The patch submissions, development or general discussions take place at linux-btrfs@vger.kernel.org mailinglist, subsciption is not required to post.
The GitHub pull requests will not be accepted directly, the preferred way is to send patches to the mailinglist instead. You can link to a branch in any git repository if the mails do not make it to the mailinglist or just for convenience (makes it easier to test).
The development model of btrfs-progs shares a lot with the kernel model. The github way is different in some ways. We, the upstream community, expect that the patches meet some criteria (often lacking in github contributions):
- one logical change per patch: eg. not mixing bugfixes, cleanups, features etc., sometimes it's not clear and will be usually pointed out during reviews
- proper subject line: eg. prefix with btrfs-progs: subpart, ... ,
descriptive yet not too long, see
git log --oneline
for some inspiration - proper changelog: the changelogs are often missing or lacking explanation why the change was made, or how is something broken, what are user-visible effects of the bug or the fix, how does an improvement help or the intended usecase
- the Signed-off-by line: this documents who authored the change, you can read
more about the
The Developer's Certificate of Origin (chapter 11)
- if you are not used to the signed-off style, your contributions won't be rejected just because of it's missing, the Author: tag will be added as a substitute in order to allow contributions without much bothering with formalities
Documentation updates
Documentation fixes or updates do not need much explanation so sticking to the code rules in the previous section is not necessary. GitHub pull requests are OK, patches could be sent to me directly and not required to be also in the mailinglist. Pointing out typos via IRC also works, although might get accidentally lost in the noise.