There are a lot of call sites where we use the following code snippet:
u8 super_block_data[BTRFS_SUPER_INFO_SIZE];
struct btrfs_super_block *sb;
u64 ret;
sb = (struct btrfs_super_block *)super_block_data;
The reason for this is, structure btrfs_super_block was smaller than
BTRFS_SUPER_INFO_SIZE.
Thus for anything with csum involved, we have to use a proper 4K buffer.
Since the recent unification of sizeof(struct btrfs_super_block), we no
longer need such workaround, and can use struct btrfs_super_block
directly to do any operation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The term 'path' is confusing as we normally use it for filesystem paths,
while for multipath it's more related to the physical path by which the
devices are connected (though it also shows up as another path in the
filesystem).
Rename the helper doing the multipath detection so it's clear what path
is meant by that.
Signed-off-by: David Sterba <dsterba@suse.com>
Since libudev doesn't provide a static version of the library for static
build btrfs-progs will have to provide manual fallback. This change does
this by parsing the udev database files hosted at /run/udev/data/.
Under that directory every block device should have a file with the
following name: bMAJ:MIN. So implement the bare minimum code necessary
to parse this file and search for the presence of DM_MULTIPATH_DEVICE_PATH
udev attribute. This could likely be racy since access to the udev
database is done outside of libudev but that's the best that can be
done when implementing this manually and is only for a limited usecase
where static build has to be used.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs-progs will happily enumerate any device which has a
btrfs filesystem on it irrespective of its type. For the majority of
use cases that's fine and there haven't been any problems with that.
However, there was a recent report that in multipath scenario when
running "btrfs fi show" after a path flap (path going down and then
coming back up) instead of the multipath device being show the device
which represents the flapped path is shown. So a multipath filesystem
might look like:
Label: none uuid: d3c1261f-18be-4015-9fef-6b35759dfdba
Total devices 1 FS bytes used 192.00KiB
devid 1 size 10.00GiB used 536.00MiB path /dev/mapper/3600140501cc1f49e5364f0093869c763
/dev/mapper/xxx is actually backed by an arbitrary number of paths,
which in turn are presented to the system as ordinary SCSI devices i.e
/dev/sdX. If a path flaps and a user re-runs 'btrfs fi show' the output
would look like:
Label: none uuid: d3c1261f-18be-4015-9fef-6b35759dfdba
Total devices 1 FS bytes used 192.00KiB
devid 1 size 10.00GiB used 536.00MiB path /dev/sdd
This only occurs on unmounted filesystems as those are enumerated by
btrfs-progs, for mounted filesystem the kernel properly deals only with
the actual multipath device.
Turns out the output of this command is consumed by libraries and the
presence of a path device rather than the actual multipath causes
issues.
Fix this by checking for the presence of DM_MULTIPATH_DEVICE_PATH
udev attribute as multipath path devices are tagged with this attribute
by the multipath udev scripts.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 8ef9313cf2 ("btrfs-progs: zoned: implement log-structured
superblock") changed to write BTRFS_SUPER_INFO_SIZE bytes to device.
The before num of bytes to be written is sectorsize.
It causes mkfs.btrfs failed on my 16k pagesize kvm:
$ /usr/bin/mkfs.btrfs -s 16k -f -mraid0 /dev/vdb2 /dev/vdb3
btrfs-progs v5.12
See http://btrfs.wiki.kernel.org for more information.
ERROR: superblock magic doesn't match
ERROR: superblock magic doesn't match
common/device-scan.c:195: btrfs_add_to_fsid: BUG_ON `ret != sectorsize`
triggered, value 1
/usr/bin/mkfs.btrfs(btrfs_add_to_fsid+0x274)[0xaaab4fe8a5fc]
/usr/bin/mkfs.btrfs(main+0x1188)[0xaaab4fe4dc8c]
/usr/lib/libc.so.6(__libc_start_main+0xe8)[0xffff7223c538]
/usr/bin/mkfs.btrfs(+0xc558)[0xaaab4fe4c558]
[1] 225842 abort (core dumped) /usr/bin/mkfs.btrfs -s 16k -f -mraid0
/dev/vdb2 /dev/vdb3
btrfs_add_to_fsid() now always calls sbwrite() to write
BTRFS_SUPER_INFO_SIZE bytes to device, so change condition of
the BUG_ON().
Also add comments for sbread() and sbwrite().
Signed-off-by: Su Yue <l@damenly.su>
Signed-off-by: David Sterba <dsterba@suse.com>
There's a group of functions that are related to opening filesystem in
various modes, this can be moved to a separate file.
Signed-off-by: David Sterba <dsterba@suse.com>
Decrease dependency on system headers, remove where they're not needed
or became stale after code moved. The path-utils.h encapsulate path
operations so include linux/limits.h here, that's where PATH_MAX is
defined.
Signed-off-by: David Sterba <dsterba@suse.com>
Superblock (and its copies) is the only data structure in btrfs which has a
fixed location on a device. Since we cannot overwrite in a sequential write
required zone, we cannot place superblock in the zone. One easy solution
is limiting superblock and copies to be placed only in conventional zones.
However, this method has two downsides: one is reduced number of superblock
copies. The location of the second copy of superblock is 256GB, which is in
a sequential write required zone on typical devices in the market today.
So, the number of superblock and copies is limited to be two. Second
downside is that we cannot support devices which have no conventional zones
at all.
To solve these two problems, we employ superblock log writing. It uses two
adjacent zones as a circular buffer to write updated superblocks. Once the
first zone is filled up, start writing into the second one. Then, when
both zones are filled up and before starting to write to the first zone
again, reset the first zone.
We can determine the position of the latest superblock by reading write
pointer information from a device. One corner case is when both zones are
full. For this situation, we read out the last superblock of each zone, and
compare them to determine which zone is older.
The following zones are reserved as the circular buffer on ZONED btrfs.
- primary superblock: offset 0B (and the following zone)
- first copy: offset 512G (and the following zone)
- Second copy: offset 4T (4096G, and the following zone)
If these reserved zones are conventional, superblock is written fixed at
the start of the zone without logging.
Currently, superblock reading/writing is done by pread/pwrite. This
commit replace the call sites with sbread/sbwrite to wrap the functions.
For zoned btrfs, btrfs_sb_io which is called from sbread/sbwrite
reverses the IO position back to a mirror number, maps the mirror number
into the superblock logging position, and do the IO.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Get the zone information (number of zones and zone size) from all the
devices, if the volume contains a zoned block device. To avoid costly
run-time zone report commands to test the device zones type during block
allocation, it also records all the zone status (zone type, write
pointer position, etc.).
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Likewise in the kernel code, provide fs_info access from struct
btrfs_device. This will help to unify the code between the kernel and
the userland.
Since fs_info can be NULL at the time of btrfs_add_to_fsid(), let's use
btrfs_open_devices() to set fs_info to the devices.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function btrfs_scan_devices() is being used by commands such as
'btrfs filesystem' and 'btrfs device', by having the verbose argument in
the btrfs_scan_devices() we can control which threads to print the
messages when verbose is enabled by the global option.
Add an option %verbose to btrfs_scan_devices().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's theoretically possible to add multiple devices with sizes that add up
to or exceed 16EiB. A file system will be created successfully but will
have a superblock with incorrect values for total_bytes and other fields.
Kernels up to v5.0 will crash when they encounter this scenario.
We need to check for overflow and reject the device if it would overflow.
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1099147
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo
David Sterba
Nikolay Borisov
Su Yue
Naohiro Aota
Anand Jain
Jeff Mahoney