This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Add a new METADATA_REMAP chunk type, which is a metadata chunk that holds the
remap tree.
This is needed for bootstrapping purposes: the remap tree can't itself
be remapped, and must be relocated the existing way, by COWing every
leaf. The remap tree can't go in the SYSTEM chunk as space there is
limited, because a copy of the chunk item gets placed in the superblock.
The changes in fs/btrfs/volumes.h are because we're adding a new block
group type bit after the profile bits, and so can no longer rely on the
const_ilog2 trick.
The sizing to 32MB per chunk, matching the SYSTEM chunk, is an estimate
here, we can adjust it later if it proves to be too big or too small.
This works out to be ~500,000 remap items, which for a 4KB block size
covers ~2GB of remapped data in the worst case and ~500TB in the best case.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add an incompat flag for the new remap-tree feature, and the constants
and definitions needed to support it.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The offload csum mode was introduced to allow developers to compare the
performance of generating checksum for data writes at different timings:
- During btrfs_submit_chunk()
This is the most common one, if any of the following condition is met
we go this path:
* The csum is fast
For now it's CRC32C and xxhash.
* It's a synchronous write
* Zoned
- Delay the checksum generation to a workqueue
However since commit dd57c78aec ("btrfs: introduce
btrfs_bio::async_csum") we no longer need to bother any of them.
As if it's an experimental build, async checksum generation at the
background will be faster anyway.
And if not an experimental build, we won't even have the offload csum
mode support.
Considering the async csum will be the new default, let's remove the
offload csum mode code.
There will be no impact to end users, and offload csum mode is still
under experimental features.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make btrfs use the library APIs instead of crypto_shash, for all
checksum computations. This has many benefits:
- Allows future checksum types, e.g. XXH3 or CRC64, to be more easily
supported. Only a library API will be needed, not crypto_shash too.
- Eliminates the overhead of the generic crypto layer, including an
indirect call for every function call and other API overhead. A
microbenchmark of btrfs_check_read_bio() with crc32c checksums shows a
speedup from 658 cycles to 608 cycles per 4096-byte block.
- Decreases the stack usage of btrfs by reducing the size of checksum
contexts from 384 bytes to 240 bytes, and by eliminating the need for
some functions to declare a checksum context at all.
- Increases reliability. The library functions always succeed and
return void. In contrast, crypto_shash can fail and return errors.
Also, the library functions are guaranteed to be available when btrfs
is loaded; there's no longer any need to use module softdeps to try to
work around the crypto modules sometimes not being loaded.
- Fixes a bug where blake2b checksums didn't work on kernels booted with
fips=1. Since btrfs checksums are for integrity only, it's fine for
them to use non-FIPS-approved algorithms.
Note that with having to handle 4 algorithms instead of just 1-2, this
commit does result in a slightly positive diffstat. That being said,
this wouldn't have been the case if btrfs had actually checked for
errors from crypto_shash, which technically it should have been doing.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove the newly introduced zoned statistics from sysfs, as sysfs can
only show a single page this will truncate the output on a busy
filesystem.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Provide statistics for zoned filesystems. These statistics include, the
number of active block-groups, how many of them are reclaimable or unused,
if the filesystem needs to be reclaimed, the currently assigned relocation
and treelog block-groups if they're present and a list of active zones.
Example:
active block-groups: 4
reclaimable: 0
unused: 2
need reclaim: false
data relocation block-group: 4294967296
active zones:
start: 1610612736, wp: 344064 used: 16384, reserved: 0, unusable: 327680
start: 1879048192, wp: 34963456 used: 131072, reserved: 0, unusable: 34832384
start: 4026531840, wp: 0 used: 0, reserved: 0, unusable: 0
start: 4294967296, wp: 0 used: 0, reserved: 0, unusable: 0
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We don't need it since we can grab fs_info from the given space_info.
So remove the fs_info argument.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we manually check the block size against 3 different values:
- 4K
- PAGE_SIZE
- MIN_BLOCKSIZE
Those 3 values can match or differ from each other. This makes it
pretty complex to output the supported block sizes.
Considering we're going to add block size > page size support soon, this
can make the support block size sysfs attribute much harder to
implement.
To make it easier, factor out a helper, btrfs_supported_blocksize() to
do a simple check for the block size.
Then utilize it in the two locations:
- btrfs_validate_super()
This is very straightforward
- supported_sectorsizes_show()
Iterate through all valid block sizes, and only output supported ones.
This is to make future full range block sizes support much easier.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Our message helpers accept NULL for the fs_info in the context that does
not provide and print the common header of the message. The use of pr_*
helpers is only for special reasons, like module loading, device
scanning or multi-line output (print-tree).
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When debugging/detecting outlier commit stalls, having an indicator that
we are currently in a long commit critical section can be very useful.
Extend the commit_stats sysfs file to also include the current commit
critical section duration.
Since this requires storing the last commit start time, use that rather
than a separate stack variable for storing the finished commit durations
as well.
This also requires slightly moving up the timing of the stats updating
to *inside* the critical section to avoid the transaction T+1 setting
the critical_section_start_time to 0 before transaction T can update its
stats, which would trigger the new ASSERT. This is an improvement in and
of itself, as it makes the stats more accurately represent the true
critical section time. It may be yet better to pull the stats up to where
start_transaction gets unblocked, rather than the next commit, but this
seems like a good enough place as well.
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce the tree-log sub-space_info, which is sub-space of
metadata space_info and dedicated for tree-log node allocation.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Current code assumes we have only one space_info for each block group type
(DATA, METADATA, and SYSTEM). We sometime need multiple space infos to
manage special block groups.
One example is handling the data relocation block group for the zoned mode.
That block group is dedicated for writing relocated data and we cannot
allocate any regular extent from that block group, which is implemented in
the zoned extent allocator. This block group still belongs to the normal
data space_info. So, when all the normal data block groups are full and
there is some free space in the dedicated block group, the space_info
looks to have some free space, while it cannot allocate normal extent
anymore. That results in a strange ENOSPC error. We need to have a
space_info for the relocation data block group to represent the situation
properly.
Adds a basic infrastructure for having a "sub-group" of a space_info:
creation and removing. A sub-group space_info belongs to one of the
primary space_infos and has the same flags as its parent.
This commit first introduces the relocation data sub-space_info, and the
next commit will introduce tree-log sub-space_info. In the future, it could
be useful to implement tiered storage for btrfs e.g. by implementing a
sub-group space_info for block groups resides on a fast storage.
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>
Currently we only support two block sizes, 4K and PAGE_SIZE.
This means on the most common architecture x86_64, we have no way to
test subpage block size. And that's exactly I have an aarch64 machine
dedicated for subpage tests.
But this is still a hurdle for a lot of btrfs developers, and to improve
the test coverage mostly on x86_64, here we enable debug builds to
accept 2K block size.
This involves:
- Introduce a dedicated minimal block size macro
BTRFS_MIN_BLOCKSIZE, which depends on if CONFIG_BTRFS_DEBUG is set.
If so it's 2K, otherwise it's 4K as usual.
- Allow 4K, PAGE_SIZE and BTRFS_MIN_BLOCKSIZE as block size
- Update subpage block size checks to be based on BTRFS_MIN_BLOCKSIZE
- Export the new supported blocksize through sysfs interfaces
As most of the subpage support is already pretty mature, there is no
extra work needed to support the extra 2K block size.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We now parse human-friendly size values (e.g. '1G', '2M') when setting
read policies.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
strncpy() is deprecated for NUL-terminated destination buffers. Use
strscpy() instead and don't zero-initialize the param array.
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For testing purposes allow to configure the read policy via module
parameter from the beginning. Available only with CONFIG_BTRFS_EXPERIMENTAL
Examples:
- Set the RAID1 balancing method to round-robin with a custom
min_contig_read of 4k:
$ modprobe btrfs read_policy=round-robin:4096
- Set the round-robin balancing method with the default
min_contiguous_read:
$ modprobe btrfs read_policy=round-robin
- Set the "devid" balancing method, defaulting to the latest device:
$ modprobe btrfs read_policy=devid
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add read policy that will force all reads to go to the given device
(specified by devid) on the RAID1 profiles.
This will be used for testing, e.g. to read from stale device. Users may
find other use cases.
Can be set in sysfs, the value format is "devid:<devid>" to the file
/sys/fs/btrfs/FSID/read_policy
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add round-robin read policy that balances reads over available devices
(all RAID1 block group profiles). Switch to the next devices is done
after a number of blocks is read, which is 256K by default and is
configurable in sysfs.
The format is "round-robin:<min-contig-read>" and can be set in file
/sys/fs/btrfs/FSID/read_policy
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable specifying additional configuration values along the RAID1
balancing read policy in a single input string.
Update btrfs_read_policy_to_enum() to parse and handle a value
associated with the policy in the format "policy:value", the value part
if present is converted to 64-bit integer.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce btrfs_read_policy_to_enum() helper to simplify the conversion
of a string read policy to its corresponding enum value. This reduces
duplication and improves code clarity in btrfs_read_policy_store().
The parameter is copied locally to allow modification, enabling the
separation of the method and its value. This prepares for the addition of
more functionality in subsequent patches.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Refactor the logic in btrfs_read_policy_show() for easier extension with
more balancing methods. Streamline the space and bracket handling
around the active policy without altering the functional output. This
is in preparation to add more methods.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The following sysfs entries are reading super block member directly,
which can have a different endian and cause wrong values:
- sys/fs/btrfs/<uuid>/nodesize
- sys/fs/btrfs/<uuid>/sectorsize
- sys/fs/btrfs/<uuid>/clone_alignment
Thankfully those values (nodesize and sectorsize) are always aligned
inside the btrfs_super_block, so it won't trigger unaligned read errors,
just endian problems.
Fix them by using the native cached members instead.
Fixes: df93589a17 ("btrfs: export more from FS_INFO to sysfs")
CC: stable@vger.kernel.org
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are advertising experimental features through sysfs if
CONFIG_BTRFS_DEBUG is set, without looking if CONFIG_BTRFS_EXPERIMENTAL
is set. This is wrong as it will result in reporting experimental
features as supported when CONFIG_BTRFS_EXPERIMENTAL is not set but
CONFIG_BTRFS_DEBUG is set.
Fix this by checking for CONFIG_BTRFS_EXPERIMENTAL instead of
CONFIG_BTRFS_DEBUG.
Fixes: 67cd3f2217 ("btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG")
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently CONFIG_BTRFS_EXPERIMENTAL is not only for the extra debugging
output, but also for experimental features.
This is not ideal to distinguish planned but not yet stable features
from those purely designed for debugging.
This patch splits the following features into CONFIG_BTRFS_EXPERIMENTAL:
- Extent map shrinker
This seems to be the first one to exit experimental.
- Extent tree v2
This seems to be the last one to graduate from experimental.
- Raid stripe tree
- Csum offload mode
- Send protocol v3
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This new mount option allows the kernel to skip the super flags check,
it's mostly to allow the kernel to do a rescue mount of an interrupted
checksum conversion.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce "rescue=ignoremetacsums" to ignore metadata csums, all the
other metadata sanity checks are still kept as is.
This new mount option is mostly to allow the kernel to mount an
interrupted checksum conversion (at the metadata csum overwrite stage).
And since the main part of metadata sanity checks is inside
tree-checker, we shouldn't lose much safety, and the new mount option is
rescue mount option it requires full read-only mount.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We currently employ a edge-triggered block group reclaim strategy which
marks block groups for reclaim as they free down past a threshold.
With a dynamic threshold, this is worse than doing it in a
level-triggered fashion periodically. That is because the reclaim
itself happens periodically, so the threshold at that point in time is
what really matters, not the threshold at freeing time. If we mark the
reclaim in a big pass, then sort by usage and do reclaim, we also
benefit from a negative feedback loop preventing unnecessary reclaims as
we crunch through the "best" candidates.
Since this is quite a different model, it requires some additional
support. The edge triggered reclaim has a good heuristic for not
reclaiming fresh block groups, so we need to replace that with a typical
GC sweep mark which skips block groups that have seen an allocation
since the last sweep.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
We can currently recover allocated block_groups by:
- explicitly starting balance operations
- "auto reclaim" via bg_reclaim_threshold
The latter works by checking against a fixed threshold on frees. If we
pass from above the threshold to below, relocation triggers and the
block group will get reclaimed by the cleaner thread (assuming it is
still eligible)
Picking a threshold is challenging. Too high, and you end up trying to
reclaim very full block_groups which is quite costly, and you don't do
reclaim on block_groups that don't get quite THAT full, but could still
be quite fragmented and stranding a lot of space. Too low, and you
similarly miss out on reclaim even if you badly need it to avoid running
out of unallocated space, if you have heavily fragmented block groups
living above the threshold.
No matter the threshold, it suffers from a workload that happens to
bounce around that threshold, which can introduce arbitrary amounts of
reclaim waste.
To improve this situation, introduce a dynamic threshold. The basic idea
behind this threshold is that it should be very lax when there is plenty
of unallocated space, and increasingly aggressive as we approach zero
unallocated space. To that end, it sets a target for unallocated space
(10 chunks) and then linearly increases the threshold as the amount of
space short of the target we are increases. The formula is:
(target - unalloc) / target
I tested this by running it on three interesting workloads:
1. bounce allocations around X% full.
2. fill up all the way and introduce full fragmentation.
3. write in a fragmented way until the filesystem is just about full.
1. and 2. attack the weaknesses of a fixed threshold; fixed either works
perfectly or fully falls apart, depending on the threshold. Dynamic
always handles these cases well.
3. attacks dynamic by checking whether it is too zealous to reclaim in
conditions with low unallocated and low unused. It tends to claw back
1GiB of unallocated fairly aggressively, but not much more. Early
versions of dynamic threshold struggled on this test.
Additional work could be done to intelligently ratchet up the urgency of
reclaim in very low unallocated conditions. Existing mechanisms are
already useless in that case anyway.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
When evaluating various reclaim strategies/thresholds against each
other, it is useful to collect data about the amount of reclaim
happening. Expose a count, error count, and byte count via sysfs
per space_info.
Note that this is only for automatic reclaim, not manually invoked
balances or other codepaths that use "relocate_block_group"
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are open coded tests of BTRFS_FS_STATE_DUMMY_FS_INFO and we have a
wrapper for that that's a compile-time constant when self-tests are not
built in. As this is only for development we can save some bytes and
conditions on release configs by using the helper in the remaining
cases.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We disable offloading checksum to workqueues and do it synchronously when
the checksum algorithm is fast. However, as reported in the link below,
RAID0 with multiple devices may suffer from the sync checksum, because
"fast checksum" is still not fast enough to catch up with RAID0 writing.
We don't have an effective way to determine whether to offload or not,
for now add a sysfs knob so this can be debugged. This is intentionally
under CONFIG_BTRFS_DEBUG so ti's not exposed to users as it may be
removed in the future agin.
Introduce fs_devices->offload_csum_mode, so that a btrfs developer can
change the behavior by writing to /sys/fs/btrfs/<uuid>/offload_csum. The
default is "auto" which is the same as the previous behavior. Or, you
can set "on" or "off" (or "y" or "n" whatever kstrtobool() accepts) to
always/never offload checksum.
More benchmark need to be collected with this knob to implement a proper
criteria to enable/disable checksum offloading.
Link: https://lore.kernel.org/linux-btrfs/20230731152223.4EFB.409509F4@e16-tech.com/
Link: https://lore.kernel.org/linux-btrfs/p3vo3g7pqn664mhmdhlotu5dzcna6vjtcoc2hb2lsgo2fwct7k@xzaxclba5tae/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The IS_ENABLED() macro already guarantees the result will be a
suitable boolean return value ("1" for enabled, and "0" for disabled).
Thus, it seems that the "!!" used right before is unnecessary to force
the 0/1 values.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we can read/modify the value from the sysfs interface concurrently,
it would be better to protect it from compiler optimizations.
Currently, there is only one read policy BTRFS_READ_POLICY_PID available,
so no actual problem can happen now. This is a preparation for the future
expansion.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The value set as scrub_speed_max accepts size with suffixes
(k/m/g/t/p/e) but we should still validate it for trailing characters,
similar to what we do with chunk_size_store.
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This adds sysfs objects to indicate temp_fsid feature support and
its status.
/sys/fs/btrfs/features/temp_fsid
/sys/fs/btrfs/<UUID>/temp_fsid
For example:
Consider two cloned and mounted devices.
$ blkid /dev/sdc[1-2]
/dev/sdc1: UUID="509ad44b-ad2a-4a8a-bc8d-fe69db7220d5" ..
/dev/sdc2: UUID="509ad44b-ad2a-4a8a-bc8d-fe69db7220d5" ..
One gets actual fsid, and the other gets the temp_fsid when
mounted.
$ btrfs filesystem show -m
Label: none uuid: 509ad44b-ad2a-4a8a-bc8d-fe69db7220d5
Total devices 1 FS bytes used 54.14MiB
devid 1 size 300.00MiB used 144.00MiB path /dev/sdc1
Label: none uuid: 33bad74e-c91b-43a5-aef8-b3cab97ae63a
Total devices 1 FS bytes used 54.14MiB
devid 1 size 300.00MiB used 144.00MiB path /dev/sdc2
Their sysfs as below.
$ cat /sys/fs/btrfs/features/temp_fsid
0
$ cat /sys/fs/btrfs/509ad44b-ad2a-4a8a-bc8d-fe69db7220d5/temp_fsid
0
$ cat /sys/fs/btrfs/33bad74e-c91b-43a5-aef8-b3cab97ae63a/temp_fsid
1
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the generation field of struct btrfs_fs_info is always modified
while holding fs_info->trans_lock locked. Most readers will access this
field without taking that lock but while holding a transaction handle,
which is safe to do due to the transaction life cycle.
However there are other readers that are neither holding the lock nor
holding a transaction handle open:
1) When reading an inode from disk, at btrfs_read_locked_inode();
2) When reading the generation to expose it to sysfs, at
btrfs_generation_show();
3) Early in the fsync path, at skip_inode_logging();
4) When creating a hole at btrfs_cont_expand(), during write paths,
truncate and reflinking;
5) In the fs_info ioctl (btrfs_ioctl_fs_info());
6) While mounting the filesystem, in the open_ctree() path. In these
cases it's safe to directly read fs_info->generation as no one
can concurrently start a transaction and update fs_info->generation.
In case of the fsync path, races here should be harmless, and in the worst
case they may cause a fsync to log an inode when it's not really needed,
so nothing bad from a functional perspective. In the other cases it's not
so clear if functional problems may arise, though in case 1 rare things
like a load/store tearing [1] may cause the BTRFS_INODE_NEEDS_FULL_SYNC
flag not being set on an inode and therefore result in incorrect logging
later on in case a fsync call is made.
To avoid data race warnings from tools like KCSAN and other issues such
as load and store tearing (amongst others, see [1]), create helpers to
access the generation field of struct btrfs_fs_info using READ_ONCE() and
WRITE_ONCE(), and use these helpers where needed.
[1] https://lwn.net/Articles/793253/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add an entry in the features directory for the new incompat flag
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a new sysfs file /sys/fs/btrfs/<uuid>/qgroups/mode
which prints out the mode qgroups is running in. The possible modes are
qgroup, and squota.
If quotas are not enabled, then the qgroups directory will not exist,
so don't handle that mode.
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
If a filesystem with a raid-stripe-tree is mounted, show the RST feature
in sysfs, currently still under the CONFIG_BTRFS_DEBUG option.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
ACL support depends on the compile-time configuration option
CONFIG_BTRFS_FS_POSIX_ACL. Prior to mounting a btrfs filesystem, it is not
possible to determine whether ACL support has been compiled in. To address
this, add a sysfs interface, /sys/fs/btrfs/features/acl, and check for ACL
support in the system's btrfs.
To determine ACL support:
Return 0 indicates ACL is not supported:
$ cat /sys/fs/btrfs/features/acl
0
Return 1 indicates ACL is supported:
$ cat /sys/fs/btrfs/features/acl
1
IMO, this is a better approach, so that we also know if kernel is older.
On an older kernel
$ ls /sys/fs/btrfs/features/acl
ls: cannot access '/sys/fs/btrfs/features/acl': No such file or directory
mount a btrfs filesystem
$ cat /proc/self/mounts | grep btrfs | grep -q noacl
$ echo $?
0
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, /sys/fs/btrfs/<UUID>/bg_reclaim_threshold is limited to 0
(disable) or [50 .. 100]%, so we need to fill 50% of a device to start the
auto reclaim process. It is cumbersome to do so when we want to shake out
possible race issues of normal write vs reclaim.
Relax the threshold check under the BTRFS_DEBUG option.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make it possible to see the distribution of size classes for block
groups. Helpful for testing and debugging the allocator w.r.t. to size
classes.
The new stats can be found at the path:
/sys/fs/btrfs/<FSID>/allocation/<bg-type>/size_class
but they will only be non-zero for bg-type = data.
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definitions to prevent
modification at runtime.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Since the introduction of per-fs feature sysfs interface
(/sys/fs/btrfs/<UUID>/features/), the content of that directory is never
updated.
Thus for the following case, that directory will not show the new
features like RAID56:
# mkfs.btrfs -f $dev1 $dev2 $dev3
# mount $dev1 $mnt
# btrfs balance start -f -mconvert=raid5 $mnt
# ls /sys/fs/btrfs/$uuid/features/
extended_iref free_space_tree no_holes skinny_metadata
While after unmount and mount, we got the correct features:
# umount $mnt
# mount $dev1 $mnt
# ls /sys/fs/btrfs/$uuid/features/
extended_iref free_space_tree no_holes raid56 skinny_metadata
[CAUSE]
Because we never really try to update the content of per-fs features/
directory.
We had an attempt to update the features directory dynamically in commit
14e46e0495 ("btrfs: synchronize incompat feature bits with sysfs
files"), but unfortunately it get reverted in commit e410e34fad
("Revert "btrfs: synchronize incompat feature bits with sysfs files"").
The problem in the original patch is, in the context of
btrfs_create_chunk(), we can not afford to update the sysfs group.
The exported but never utilized function, btrfs_sysfs_feature_update()
is the leftover of such attempt. As even if we go sysfs_update_group(),
new files will need extra memory allocation, and we have no way to
specify the sysfs update to go GFP_NOFS.
[FIX]
This patch will address the old problem by doing asynchronous sysfs
update in the cleaner thread.
This involves the following changes:
- Make __btrfs_(set|clear)_fs_(incompat|compat_ro) helpers to set
BTRFS_FS_FEATURE_CHANGED flag when needed
- Update btrfs_sysfs_feature_update() to use sysfs_update_group()
And drop unnecessary arguments.
- Call btrfs_sysfs_feature_update() in cleaner_kthread
If we have the BTRFS_FS_FEATURE_CHANGED flag set.
- Wake up cleaner_kthread in btrfs_commit_transaction if we have
BTRFS_FS_FEATURE_CHANGED flag
By this, all the previously dangerous call sites like
btrfs_create_chunk() need no new changes, as above helpers would
have already set the BTRFS_FS_FEATURE_CHANGED flag.
The real work happens at cleaner_kthread, thus we pay the cost of
delaying the update to sysfs directory, but the delayed time should be
small enough that end user can not distinguish though it might get
delayed if the cleaner thread is busy with removing subvolumes or
defrag.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The div_factor* helpers calculate fraction or percentage fraction. The
name is a bit confusing, we use it only for percentage calculations and
there are two helpers.
There's a helper mult_frac that's for general fractions, that tries to
be accurate but we multiply and divide by small numbers so we can use
the div_u64 helper.
Rename the div_factor* helpers and use 1..100 percentage range, also drop
the case checking for percentage == 100, it's never hit.
The conversions:
* div_factor calculates tenths and the numbers need to be adjusted
* div_factor_fine is direct replacement
Signed-off-by: David Sterba <dsterba@suse.com>
