The new hard link detection and creation support is done by maintaining
an rb tree with the following members:
- st_ino, st_dev
This is to record the stat() report from the host fs.
With this two, we can detect if it's really a hard link (st_dev
determines one filesystem/subvolume, and st_ino determines the inode
number inside the fs).
- root
This is btrfs root pointer. This a special requirement for the recent
introduced "--subvol" option.
As we can have the following corner case:
rootdir/
|- foobar_hardlink1
|- foobar_hardlink2
|- subv/ <- To be a subvolume inside btrfs
|- foobar_hardlink3
In above case, on the host fs, `subv/` directory is just a regular
directory, but in the new btrfs it will be a subvolume.
In that case, `foobar_hardlink3` cannot be created as a hard link,
but a new inode.
- st_nlink and found_nlink
Records the original reported number of links, and the nlinks we
created inside btrfs.
This is recorded in case we created all hard links and can remove
the entry early.
- btrfs_ino
This is the inode number inside btrfs.
And since we can handle hard links safely, remove all the related
warnings, and add a new note for `--subvol` option, warning about the
case where we need to split hard links due to subvolume boundary.
Pull-request: #873
Signed-off-by: Qu Wenruo <wqu@suse.com>
Change --subvol that it can accept flags, and add a "default" flag that
allows you to mark a subvolume as the default.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Add a new option --subvol, which tells mkfs.btrfs to create the
specified directories as subvolumes when used with --rootdir.
Given a populated directory dir, the command
$ mkfs.btrfs --rootdir dir --subvol usr --subvol home --subvol home/username img
will create subvolumes 'usr' and 'home' within the toplevel subvolume,
and subvolume 'username' within the 'home' subvolume. It will fail if
any of the directories do not yet exist.
Pull-request: #868
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add new option --recursive 'btrfs subvol delete', causing it to pass the
BTRFS_UTIL_DELETE_SUBVOLUME_RECURSIVE flag through to libbtrfsutil.
This can work in two modes, depending on the user:
- regular user - this will skip subvolumes that are not accessible
- root (CAP_SYS_ADMIN) - no limitations
Pull-request: #861
Signed-off-by: Mark Harmstone <maharmstone@meta.com>
Co-authored-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ Add details to man page, fix indent in the doc. ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Explain the difference, in case somebody want's to use it as a source to
correct that on Wikipedia.
[ ci skip ]
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs-ioctl.rst was laid out like it should be a man page, including
having a section number, but it wasn't getting installed because there
was not enough content.
Pull-request: #892
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Added 0x prefix to HEX numbers and transform some tables to new format.
Pull-request: #881
Signed-off-by: Yuwei Han <hrx@bupt.moe>
[ Fix RST grammar errors ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
The way the CRC32C checksum used for btrfs-send differs from the way
it's used elsewhere in btrfs. Without making the distinction, it's easy
to make the flawed assumption that CRC32C always refers to the same, and
end up with code that produces the wrong checksums.
This small note should guide the reader to the right function.
The best notes on the protocol I found are here:
https://archive.kernel.org/oldwiki/btrfs.wiki.kernel.org/index.php/Design_notes_on_Send/Receive.html
The crc32c might be used in two meanings and this could be confusing
when implementing the send stream protocol.
Rust code describing the algorithm for the crc crate that worked for me:
pub const CRC_32_BTRFS_SEND: crc::Algorithm<u32> = crc::Algorithm {
width: 32, poly: 0x1edc6f41, init: 0, refin: true, refout: true,
xorout: 0, check: 0xe3069283, residue: 0xb798b438
};
(it's a slight variation on the one used in ISCSI)
Note: Documentation/dev/dev-send-stream.rst briefly mentions that
Pull-request: #794
Author: rhn <gihu.rhn@porcupinefactory.org>
[ rephrase changelog and copy text from pull request and add link to
developer documentation of the send stream ]
Signed-off-by: David Sterba <dsterba@suse.com>
Make it more visible what the result of snapshotted subvolume is. This
partially duplicates the other section.
[ci skip]
Issue: #644
Signed-off-by: David Sterba <dsterba@suse.com>
It is possible to create swapfile on a multi-device filesystem but it's
not reliable. The check that verifies that in kernel:
10698 } else if (device != map->stripes[0].dev) {
10699 btrfs_warn(fs_info, "swapfile must be on one device");
10700 ret = -EINVAL;
10701 goto out;
10702 }
This does not count devices but rather the actual placement of the
swapfile extents, so multi-device filesystem with single profile can
create it as long as there's enough space and the allocator decides to
place it properly.
[ci skip]
Pull-request: #839
Signed-off-by: David Sterba <dsterba@suse.com>
The filename sanitization is not recommended as it introduces mismatches
between DIR_ITEM and INODE_REF.
Even hash collision mode (double "-s" option) is not ensured to always
find a hash collision, and when fails to find one, a mismatch happens.
And when a mismatch happens, the kernel will not resolve the path
correctly since kernel uses the hash from DIR_ITEM to lookup the child
inode.
So add a warning into the "-s" option of btrfs-image.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Filenames can contain a newline (or other funny characters), this makes
the dump-tree output confusing, same for xattr names or values that can
binary data. Encode the special characters in the C-style ('\e' ->
"\e", or \NNN if there's no single letter representation). This is based
on the isprint() as it's espected either on a terminal or in a dump
file.
Issue: #350
Issue: #407
Signed-off-by: David Sterba <dsterba@suse.com>
Similar to the manual page on terminal preview, also do the html output
that will be on the RTD page. Due to the way how it's displayed in the
CI action summary the CSS is missing and there are some visual
artifacts, e.g. in the option lists or special characters.
Issue: #824
Signed-off-by: David Sterba <dsterba@suse.com>
tree-stats currently displays only some global trees and fs-tree 5. Add
support to show the stats of a specified tree.
Issue: #268
Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Extend CI workflow of devel branch to generate manual page preview as it
would be rendered in a terminal. The output is in the workflow summary
page, for each file changed (if any).
Issue: #824
Signed-off-by: David Sterba <dsterba@suse.com>
Enhance the rescue mount option group by:
- Add a simple explanation on each rescue option
- Add the new 'ignoremetacsums' option
Signed-off-by: Qu Wenruo <wqu@suse.com>
Recent patches updated stale qgroup handling, using 'unlinked' and
'dropped' where we otherwise use 'deleted' and 'cleaned'.
Signed-off-by: David Sterba <dsterba@suse.com>
Currently `btrfs qgroup show` command shows any 0 level qgroup without a
root backref as `<stale>`, which is not correct.
There are several more cases:
- Under deletion
The subvolume is not yet full dropped, but unlinked.
In that case we would not have a root backref item, but the qgroup is
not stale.
- Squota space holder
This is for squota mode, that a fully dropped subvolume still have
extents accounting on the already-gone subvolume.
In this case it's not stale either, and future accounting relies on
it.
This patch would add above special cases, and add an extra `SPECIAL
PATHS` section to explain all the cases, including `<stale>`.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The inode_cache functionality is long gone and the 'rescue' group
provides the clearning functionality, no point keeping it in check.
Move the --clear-space-cache option to the deprecaeted section so it can
be removed soon.
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 9da773aa46.
There are several problems related to the --delete-qgroup option:
- Currently kernel doesn't allow to delete non-empty qgroups
- A qgroup can only be empty after fully dropped and a transaction is
committed
The tool doesn't take either factor into consideration
- Things like drop_subtree_threshold or other operations can mark qgroup
inconsistent and skip accounting
This can mean the target qgroup will never be empty until next rescan
On the other hand, even we do it the proper way, it would hugely delay
the command (wait until the subvolume to be cleaned).
Furthermore, even if the waiting is handled properly,
drop_subtree_threshold can still prevent us deleting the qgroup (qgroup
numbers are inconsistent, and accounting is skipped completely).
So the qgroup cleanup needs kernel to make it work properly.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Since commit 8049446bb0 ("btrfs-progs: docs: placeholder for
contents.rst file on older sphinx version"), on systems with much newer
sphinx-build, "make" would not work for Documentation directory:
$ make clean-all && ./autogen.sh && ./configure --prefix=/usr/ && make -j12
$ ls -alh Documentation/_build
ls: cannot access 'Documentation/_build': No such file or directory
The sphinx-build has a much newer version:
$ sphinx-build --version
sphinx-build 7.2.6
[CAUSE]
On systems which don't need the workaround, the phony target of
contents.rst seems to cause a dependency loop:
GNU Make 4.4.1
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2023 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Reading makefiles...
Reading makefile 'Makefile'...
Updating makefiles....
Considering target file 'Makefile'.
Looking for an implicit rule for 'Makefile'.
Trying pattern rule '%:' with stem 'Makefile'.
Found implicit rule '%:' for 'Makefile'.
Finished prerequisites of target file 'Makefile'.
No need to remake target 'Makefile'.
Updating goal targets....
Considering target file 'contents.rst'.
File 'contents.rst' does not exist.
Finished prerequisites of target file 'contents.rst'.
Must remake target 'contents.rst'.
Makefile:35: update target 'contents.rst' due to: target is .PHONY
if [ "$(sphinx-build --version | cut -d' ' -f2)" \< "1.7.7" ]; then \
touch contents.rst; \
fi
Putting child 0x64ee81960130 (contents.rst) PID 66833 on the chain.
Live child 0x64ee81960130 (contents.rst) PID 66833
Reaping winning child 0x64ee81960130 PID 66833
Removing child 0x64ee81960130 PID 66833 from chain.
Successfully remade target file 'contents.rst'.
All the default make doing is just try to generate contents.rst, but
since we have much newer version, we won't generate the file at all.
[FIX]
Instead of a phony target, just move the contents.rst generation into
man page target so that we won't cause loop target on contents.rst.
Fixes: 8049446bb0 ("btrfs-progs: docs: placeholder for contents.rst file on older sphinx version")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add some missing entries. Changes to supported levels:
- increase to 6.8 from 6.7 where applicable, there were fixes to squota
and temp-fsid
- raid-stripe-tree declares support from 6.7, however this is still
behind CONFIG_BTRFS_DEBUG option in kernel, there are some bugs
and the known lack of RAID56 support
[ci skip]
Signed-off-by: David Sterba <dsterba@suse.com>
A user who wants to shrink a btrfs filesystem within some other logical
device (like a partition) will likely want to adapt the size of the
underlying device, too.
This commit adds documentation that describes how the length of the
portion that btrfs uses of some device can be found out.
Thanks go out to Roman Mamedov <rm@romanrm.net> for hinting `btrfs
filesystem show` as alternative command.
Note: the granularity is one sectorsize and the input values are
silently rounded down to avoid bugs from converted filesystems that
would not adhere to the native btrfs constraints.
[ci skip]
Pull-request: #775
Signed-off-by: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>
Signed-off-by: David Sterba <dsterba@suse.com>
