As the delayed root is now in the fs_info we can pass it to
btrfs_first_delayed_node().
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
In all cases the delayed_root is used once in a function, we don't need
to use a local variable for that.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_info::delayed_root is allocated dynamically but there's only one
instance per filesystem so we can embed it into the fs_info itself.
The two object have the same lifetime and delayed roots are always
present so we don't need to allocate it on demand from slab.
There's still some space left in fs_info until the 4K so there won't be
an spill over to next page on release config (size grows from 3880 to
3952). In case we want to shrink fs_info there are still holes to fill
or we can separate other non-core or optional structures if needed.
Link: https://lore.kernel.org/all/cover.1767979013.git.dsterba@suse.com/
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we do not check the alignment of extent_map structure.
The reasons are the inode and extent-map tests use unaligned values
for start offsets and lengths.
Thankfully those legacy problems are properly addressed by previous
patches, now we can finally put the alignment checks into
validate_extent_map().
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the extent map self tests have the following points that will
cause false alerts for the incoming strict extent map alignment checks:
- Incorrect inlined extent map size
Which is not following what the kernel is doing for inlined extents,
as btrfs_extent_item_to_extent_map() always uses the fs block size as
the length, not the ram_bytes.
Fix it by using SZ_4K as extent map's length.
- Incorrect btrfs_fs_info::sectorsize
As we always use PAGE_SIZE, which can be values larger than 4K.
Meanwhile all the immediate numbers used are based on 4K fs block size
in the test case.
Fix it by using fixed SZ_4K fs block size when allocating the dummy
btrfs_fs_info.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the inode self tests, there are several problems:
- Invalid file extents
E.g. hole range [4K, 4K + 4) is completely invalid.
Only inlined extent maps can have an unaligned ram_bytes, and even for
that case, the generated extent map will use sectorsize as em->len.
- Unaligned hole after inlined extent
The kernel never does this by itself, the current btrfs_get_extent()
will only return a single inlined extent map that covers the first
block.
- Incorrect numbers in the comment
E.g. 12291 no matter if you add or dec 1, is not aligned to 4K.
The properly number for 12K is 12288, I don't know why there is even a
diff of 3, and this completely doesn't match the extent map we
inserted later.
- Hard-to-modify sequence in setup_file_extents()
If some unfortunate person, just like me, needs to modify
setup_file_extents(), good luck not screwing up the file offset.
Fix them by:
- Remove invalid unaligned extent maps
This mostly means remove the [4K, 4K + 4) hole case.
The remaining ones are already properly aligned.
This slightly changes the on-disk data extent allocation, with that
removed, the regular extents at [4K, 8K) and [8K , 12K) can be merged.
So also add a 4K gap between those two data extents to prevent em
merge.
- Remove the implied hole after an inlined extent
Just like what the kernel is doing for inlined extents in the real
world.
- Update the commit using proper numbers with 'K' suffixes
Since there is no unaligned range except the first inlined one, we can
always use numbers with 'K' suffixes, which is way more easier to read,
and will always be aligned to 1024 at least.
- Add comments in setup_file_extents()
So that we're clear about the file offset for each test file extent.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a single transaction abort that can be caused either by a failure
from a call to btrfs_mark_extent_written(), if we are dealing with a
write to a prealloc extent, or otherwise from a call to
insert_ordered_extent_file_extent(). So when the transaction abort happens
we can not know for sure which case failed. Unfold the aborts so that it's
clear in case of a failure.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In case the root does not exists, which is unexpected, btrfs_extent_root()
returns NULL, but we ignore that and so if it happens we can trigger a
NULL pointer dereference later. So verify if we found the root and log an
error message in case it's missing.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need to pass the maximum between the block group's start offset
and BTRFS_SUPER_INFO_OFFSET (64K) since we can't have any block groups
allocated in the first megabyte, as that's reserved space. Furthermore,
even if we could, the correct thing to do was to pass the block group's
start offset anyway - and that's precisely what we do for block groups
that happen to contain superblock mirror (the range for the super block
is never marked as free and it's marked as dirty in the
fs_info->excluded_extents io tree).
So simplify this and get rid of that maximum expression.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BACKGROUND]
Inspired by a recent kernel bug report, which is related to direct IO
buffer modification during writeback, that leads to contents mismatch of
different RAID1 mirrors.
[CAUSE AND PROBLEMS]
The root cause is exactly the same explained in commit 968f19c5b1
("btrfs: always fallback to buffered write if the inode requires
checksum"), that we can not trust direct IO buffer which can be modified
halfway during writeback.
Unlike data checksum verification, if this happened on inodes without
data checksum but has the data has extra mirrors, it will lead to
stealth data mismatch on different mirrors.
This will be way harder to detect without data checksum.
Furthermore for RAID56, we can even have data without checksum and data
with checksum mixed inside the same full stripe.
In that case if the direct IO buffer got changed halfway for the
nodatasum part, the data with checksum immediately lost its ability to
recover, e.g.:
" " = Good old data or parity calculated using good old data
"X" = Data modified during writeback
0 32K 64K
Data 1 | | Has csum
Data 2 |XXXXXXXXXXXXXXXX | No csum
Parity | |
In above case, the parity is calculated using data 1 (has csum, from
page cache, won't change during writeback), and old data 2 (has no csum,
direct IO write).
After parity is calculated, but before submission to the storage, direct
IO buffer of data 2 is modified, causing the range [0, 32K) of data 2
has a different content.
Now all data is submitted to the storage, and the fs got fully synced.
Then the device of data 1 is lost, has to be rebuilt from data 2 and
parity. But since the data 2 has some modified data, and the parity is
calculated using old data, the recovered data is no the same for data 1,
causing data checksum mismatch.
[FIX]
Fix the problem by checking the data allocation profile.
If our data allocation profile is either RAID0 or SINGLE, we can allow
true zero-copy direct IO and the end user is fully responsible for any
race.
However this is not going to fix all situations, as it's still possible
to race with balance where the fs got a new data profile after the data
allocation profile check.
But this fix should still greatly reduce the window of the original bug.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=99171
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's supposed to be called with the block group locked, in order to read
and set its size_class member, so assert it's locked.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need to pass the block group since we can extract it from
the given caching control structure. Same goes for its helper function
sample_block_group_extent_item().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of allocating and freeing a path in every iteration of
load_block_group_size_class(), through its helper function
sample_block_group_extent_item(), allocate the path in the former and
pass it to the later. The path is allocated on stack since it's short
and we are in a workqueue context so there's not much stack usage.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no point in returning anything since determining and setting a
size class for a block group is an optimization, not something critical.
The only caller of load_block_group_size_class() (the caching thread)
does not do anything with the return value anyway, exactly because having
a size class is just an optimization and it can always be set later when
adding reserved bytes to a block group (btrfs_add_reserved_bytes()).
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.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 zstd_decompress_bio() is using
compressed_bio->compressed_folios[] array to grab each compressed folio.
However cb->compressed_folios[] is just a pointer to each folio of the
compressed bio, meaning we can just replace the compressed_folios[]
array by just grabbing the folio inside the compressed bio.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently zlib_decompress_bio() is using
compressed_bio->compressed_folios[] array to grab each compressed folio.
However cb->compressed_folios[] is just a pointer to each folio of the
compressed bio, meaning we can just replace the compressed_folios[]
array by just grabbing the folio inside the compressed bio.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently lzo_decompress_bio() is using
compressed_bio->compressed_folios[] array to grab each compressed folio.
This is making the code much easier to read, as we only need to maintain
a single iterator, @cur_in, and can easily grab any random folio using
@cur_in >> min_folio_shift as an index.
However lzo_decompress_bio() itself is ensured to only advance to the
next folio at one time, and compressed_folios[] is just a pointer to
each folio of the compressed bio, thus we have no real random access
requirement for lzo_decompress_bio().
Replace the compressed_folios[] access by a helper, get_current_folio(),
which uses folio_iter and an external folio counter to properly switch
the folio when needed.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Move the filesystem state validation from btrfs_reclaim_bgs_work() into
btrfs_should_reclaim() to centralize the reclaim eligibility logic.
Since it is the only caller of btrfs_should_reclaim(), there's no
functional change.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Problems with current implementation:
1. reclaimable_bytes is signed while chunk_sz is unsigned, causing
negative reclaimable_bytes to trigger reclaim unexpectedly
2. The "space must be freed between scans" assumption breaks the
two-scan requirement: first scan marks block groups, second scan
reclaims them. Without the second scan, no reclamation occurs.
Instead, track actual reclaim progress: pause reclaim when block groups
will be reclaimed, and resume only when progress is made. This ensures
reclaim continues until no further progress can be made. And resume
periodic reclaim when there's enough free space.
And we take care if reclaim is making any progress now, so it's
unnecessary to set periodic_reclaim_ready to false when failed to reclaim
a block group.
Fixes: 813d4c6422 ("btrfs: prevent pathological periodic reclaim loops")
CC: stable@vger.kernel.org # 6.12+
Suggested-by: Boris Burkov <boris@bur.io>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need to pass both the block_group and block_group::io_ctl to
__btrfs_write_out_cache().
Remove passing io_ctl to __btrfs_write_out_cache() and dereference it
inside __btrfs_write_out_cache().
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>
We have a helper to calculate an extent map's exclusive end offset, but
we only use it in some places. Update every site that open codes the
calculation to use the helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a helper to calculate a block group's exclusive end offset, but
we only use it in some places. Update every site that open codes the
calculation to use the helper.
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>
Dan reported a new smatch warning in free-space-cache.c:
New smatch warnings:
fs/btrfs/free-space-cache.c:1207 write_pinned_extent_entries() warn: variable dereferenced before check 'block_group' (see line 1203)
But the check if the block_group pointer is NULL is bogus, because to
get to this point block_group::io_ctl has already been dereferenced
further up the call-chain when calling __btrfs_write_out_cache() from
btrfs_write_out_cache().
Remove the bogus checks for block_group == NULL in
__btrfs_write_out_cache() and it's siblings.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202601170636.WsePMV5H-lkp@intel.com/
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>
Add a function btrfs_populate_fully_remapped_bgs_list() which gets
called on mount, which looks for fully remapped block groups
(i.e. identity_remap_count == 0) which haven't yet had their chunk
stripes and device extents removed.
This happens when a filesystem is unmounted while async discard has not
yet finished, as otherwise the data range occupied by the chunk stripes
would be permanently unusable.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Discard normally works by iterating over the free-space entries of a
block group. This doesn't work for fully-remapped block groups, as we
removed their free-space entries when we started relocation.
For sync discard, call btrfs_discard_extent() when we commit the
transaction in which the last identity remap was removed.
For async discard, add a new function btrfs_trim_fully_remapped_block_group()
to be called by the discard worker, which iterates over the block
group's range using the normal async discard rules. Once we reach the
end, remove the chunk's stripes and device extents to get back its free
space.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Balancing the METADATA_REMAP chunk, i.e. the chunk in which the remap tree
lives, is a special case.
We can't use the remap tree itself for this, as then we'd have no way to
boostrap it on mount. And we can't use the pre-remap tree code for this
as it relies on walking the extent tree, and we're not creating backrefs
for METADATA_REMAP chunks.
So instead, if a balance would relocate any METADATA_REMAP block groups, mark
those block groups as readonly and COW every leaf of the remap tree.
There's more sophisticated ways of doing this, such as only COWing nodes
within a block group that's to be relocated, but they're fiddly and with
lots of edge cases. Plus it's not anticipated that
a) the number of METADATA_REMAP chunks is going to be particularly large, or
b) that users will want to only relocate some of these chunks - the main
use case here is to unbreak RAID conversion and device removal.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_discard_extent() can be called either when an extent is removed
or from walking the free-space tree. With a remapped block group these
two things are no longer equivalent: the extent's addresses are
remapped, while the free-space tree exclusively uses underlying
addresses.
Add a do_remap parameter to btrfs_discard_extent() and
btrfs_map_discard(), saying whether or not the address needs to be run
through the remap tree first.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a function do_remap_tree_reloc(), which does the actual work of
doing a relocation using the remap tree.
In a loop we call do_remap_reloc_trans(), which searches for the first
identity remap for the block group. We call btrfs_reserve_extent() to
find space elsewhere for it, and read the data into memory and write it
to the new location. We then carve out the identity remap and replace it
with an actual remap, which points to the new location in which to look.
Once the last identity remap has been removed we call
last_identity_remap_gone(), which, as with deletions, removes the
chunk's stripes and device extents.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If when relocating a block group we find that `remap_bytes` > 0 in its
block group item, that means that it has been the destination block
group for another that has been remapped.
We need to search the remap tree for any remap backrefs within this
range, and move the data to a third block group. This is because
otherwise btrfs_translate_remap() could end up following an unbounded
chain of remaps, which would only get worse over time.
We only relocate one block group at a time, so `remap_bytes` will only
ever go down while we are doing this. Once we're finished we set the
REMAPPED flag on the block group, which will permanently prevent any
other data from being moved to within it.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Handle the preliminary work for relocating a block group in a filesystem
with the remap-tree flag set.
If the block group is SYSTEM btrfs_relocate_block_group() proceeds as it
does already, as bootstrapping issues mean that these block groups have
to be processed the existing way. Similarly with METADATA_REMAP blocks, which
are dealt with in a later patch.
Otherwise we walk the free-space tree for the block group in question,
recording any holes. These get converted into identity remaps and placed
in the remap tree, and the block group's REMAPPED flag is set. From now
on no new allocations are possible within this block group, and any I/O
to it will be funnelled through btrfs_translate_remap(). We store the
number of identity remaps in `identity_remap_count`, so that we know
when we've removed the last one and the block group is fully remapped.
The change in btrfs_read_roots() is because data relocations no longer
rely on the data reloc tree as a hidden subvolume in which to do
snapshots.
(Thanks to Sun YangKai for his suggestions.)
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Handle the case where we free an extent from a block group that has the
REMAPPED flag set. Because the remap tree is orthogonal to the extent
tree, for data this may be within any number of identity remaps or
actual remaps. If we're freeing a metadata node, this will be wholly
inside one or the other.
btrfs_remove_extent_from_remap_tree() searches the remap tree for the
remaps that cover the range in question, then calls
remove_range_from_remap_tree() for each one, to punch a hole in the
remap and adjust the free-space tree.
For an identity remap, remove_range_from_remap_tree() will adjust the
block group's `identity_remap_count` if this changes. If it reaches
zero we mark the block group as fully remapped.
For an identity remap, remove_range_from_remap_tree() will adjust the
block group's `identity_remap_count` if this changes. If it reaches
zero we mark the block group as fully remapped.
Fully remapped block groups have their chunk stripes removed and their
device extents freed, which makes the disk space available again to the
chunk allocator. This happens asynchronously: in the cleaner thread for
sync discard and nodiscard, and (in a later patch) in the discard worker
for async discard.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Change btrfs_map_block() so that if the block group has the REMAPPED
flag set, we call btrfs_translate_remap() to obtain a new address.
btrfs_translate_remap() searches the remap tree for a range
corresponding to the logical address passed to btrfs_map_block(). If it
is within an identity remap, this part of the block group hasn't yet
been relocated, and so we use the existing address.
If it is within an actual remap, we subtract the start of the remap
range and add the address of its destination, contained in the item's
payload.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we encounter a filesystem with the remap-tree incompat flag set,
validate its compatibility with the other flags, and load the remap tree
using the values that have been added to the superblock.
The remap-tree feature depends on the free-space-tree, but no-holes and
block-group-tree have been made dependencies to reduce the testing
matrix. Similarly I'm not aware of any reason why mixed-bg and zoned would be
incompatible with remap-tree, but this is blocked for the time being
until it can be fully tested.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a struct btrfs_block_group_item_v2, which is used in the block group
tree if the remap-tree incompat flag is set.
This adds two new fields to the block group item: `remap_bytes` and
`identity_remap_count`.
`remap_bytes` records the amount of data that's physically within this
block group, but nominally in another, remapped block group. This is
necessary because this data will need to be moved first if this block
group is itself relocated. If `remap_bytes` > 0, this is an indicator to
the relocation thread that it will need to search the remap-tree for
backrefs. A block group must also have `remap_bytes` == 0 before it can
be dropped.
`identity_remap_count` records how many identity remap items are located
in the remap tree for this block group. When relocation is begun for
this block group, this is set to the number of holes in the free-space
tree for this range. As identity remaps are converted into actual remaps
by the relocation process, this number is decreased. Once it reaches 0,
either because of relocation or because extents have been deleted, the
block group has been fully remapped and its chunk's device extents are
removed.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename the field commit_used in struct btrfs_block_group to last_used,
for clarity and consistency with the similar fields we're about to add.
It's not obvious that commit_flags means "flags as of the last commit"
rather than "flags related to a commit".
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is the following potential problem with the remap tree and delayed refs:
* Remapped extent freed in a delayed ref, which removes an entry from the
remap tree
* Remap tree now small enough to fit in a single leaf
* Corruption as we now have a level-0 block with a level-1 metadata item
in the extent tree
One solution to this would be to rework the remap tree code so that it operates
via delayed refs. But as we're hoping to remove cow-only metadata items in the
future anyway, change things so that the remap tree doesn't have any entries in
the extent tree. This also has the benefit of reducing write amplification.
We also make it so that the clear_cache mount option is a no-op, as with the
extent tree v2, as the free-space tree can no longer be recreated from the
extent tree.
Finally disable relocating the remap tree itself, which is added back in
a later patch. As it is we would get corruption as the traditional
relocation method walks the extent tree, and we're removing its metadata
items.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
No new allocations can be done from block groups that have the REMAPPED
flag set, so there's no value in their having entries in the free-space
tree.
Prevent a search through the free-space tree being scheduled for such a
block group, and prevent any additions to the in-memory free-space tree.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a chunk has been fully remapped, we are going to set its
num_stripes to 0, as it will no longer represent a physical location on
disk.
Change tree-checker to allow for this, and fix read_one_chunk() to avoid
a divide by zero.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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>
We have currently three places that compute how much available space a
block group has. Add a helper function for this and use it in those
places.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We don't expect to get errors unless we have a corrupted fs, bad RAM or a
bug. So tag the error handling as unlikely.
This slightly reduces the module's text size on x86_64 using gcc 14.2.0-19
from Debian.
Before this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1939458 172512 15592 2127562 2076ca fs/btrfs/btrfs.ko
After this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1939398 172512 15592 2127502 20768e fs/btrfs/btrfs.ko
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no need for an else branch to deal with an unexpected delayed ref
type. We can just change the previous branch to deal with this by checking
if the ref type is not BTRFS_EXTENT_OWNER_REF_KEY, since that branch is
useless as it only sets 'ret' to zero when it's already zero. So merge the
two branches.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no need to BUG(), we can just return an error and log an error
message.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_verify_dev_extents() iterates through the entire device tree
during mount to verify dev extents against chunks. Since this function
scans the whole tree, READA_FORWARD_ALWAYS is more appropriate than
READA_FORWARD.
While the device tree is typically small (a few hundred KB even for
multi-TB filesystems), using the correct readahead mode for full-tree
iteration is more consistent with the intended usage.
Signed-off-by: robbieko <robbieko@synology.com>
Signed-off-by: jinbaohong <jinbaohong@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are two main causes of holes inside btrfs_device:
- The single bytes member of last_flush_error
Not only it's a single byte member, but we never really care about the
exact error number.
- The @devt member
Which is placed between two u64 members.
Shrink the size of btrfs_device by:
- Use a single bit flag for flush error
Use BTRFS_DEV_STATE_FLUSH_FAILED so that we no longer need that
dedicated member.
- Move @devt to the hole after dev_stat_values[]
This reduces the size of btrfs_device from 528 to exact 512 bytes for
x86_64.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make the comment more detailed about why we need to flush delalloc and
wait for ordered extent completion before attempting to invalidate the
page cache.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@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>
There are two tests in btrfs_fs_closing() but checking the
BTRFS_FS_CLOSING_DONE bit is done only in one place
load_extent_tree_free(). As this is an inline we can reduce size of the
generated code. The types can be also changed to bool as this becomes a
simple condition.
text data bss dec hex filename
1674006 146704 15560 1836270 1c04ee pre/btrfs.ko
1673772 146704 15560 1836036 1c0404 post/btrfs.ko
DELTA: -234
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba
Qu Wenruo
Filipe Manana
Sun YangKai
Johannes Thumshirn
Mark Harmstone
jinbaohong