At unlink_extrefs_not_in_log() we do an inode lookup of the directory but
we already have the directory inode accessible as a function argument, so
the lookup is redudant. Remove it and use the directory inode passed in as
an argument.
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 passing the inode and parent inode object IDs to
__add_inode_ref() and its helpers because we can get them by calling
btrfs_ino() against the inode and the directory inode, and we pass both
inodes to __add_inode_ref() and its helpers. So remove the object IDs
parameters to reduce arguments passed and to make things less confusing.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While replaying log trees we need to do searches and updates to subvolume
trees and for that we use a path that we allocate in replay_one_buffer()
and then pass it as a parameter to other functions deeper in the log
replay call chain. Instead of passing it as parameter, add it to struct
walk_control since we pass a pointer to that structure for every log
replay function.
This reduces the number of arguments passed to the functions and it will
be needed and important for an upcoming changes that improves error
reporting for log replay. Also name the new filed in struct walk_control
to 'subvol_path' - while that is longer to type, the naming makes it clear
it's used for subvolume tree operations since many of the log replay
functions operate both on subvolume and log trees, and for the log tree
searches we have struct walk_control::log_leaf to also make it obvious
it's an extent buffer for a log tree extent buffer.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At overwrite_item() we have a redundant btrfs_release_path() just before
failing with -ENOMEM, as the caller who passed in the path will free it
and therefore also release any refcounts and locks on the extent buffers
of the path. So remove it.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At replay_one_one() we have a redundant btrfs_release_path() just before
calling insert_one_name(), as some lines above we have already released
the path with another btrfs_release_path() call. So remove it.
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 allocate 'fixup_path' at replay_one_dir_item(), as the
path passed as an argument is unused by the time link_to_fixup_dir() is
called (replay_one_name() releases the path before it returns).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can avoid a path allocation in the btrfs_drop_extents() calls we have
at replay_one_extent() and replay_one_buffer() by passing the path we
already have in those contextes as it's unused by the time they call
btrfs_drop_extents().
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 allocate a path as our single caller already has a
path that we can use. So pass the caller's path and use it.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A lot of the log replay functions get passed the current log leaf being
processed as well as the current slot and the key at that slot. Instead
of passing them as parameters, add them to struct walk_control so that
we reduce the numbers of parameters. This is also going to be needed to
further changes that improve error reporting during log replay.
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 this boolean 'inode_item' to tell if we are processing an inode
item key and we use it in a couple of places while in another two places
we open code by checking if the key type matches the inode item type.
Make this consistent and use the boolean everywhere. Also rename it from
'inode_item' to 'is_inode_item', which makes it more clear that it's a
boolean and not an instance of struct btrfs_inode_item, and make it const
too.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We already have the extent buffer's level in an argument, there's no need
to first ensure the extent buffer's data is loaded (by calling
btrfs_read_extent_buffer()) and then call btrfs_header_level() to check
the level. So use the level argument and do the check before calling
btrfs_read_extent_buffer().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We already have the extent buffer's level in an argument, there's no need
to call btrfs_header_level(). So use the level argument and make the code
shorter.
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 passing the transaction and subvolume root as arguments to
overwrite_item(), pass the walk_control structure as we can grab them
from the structure. This reduces the number of arguments passed and it's
going to be needed by an incoming change that improves error reporting
for log replay.
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 passing the transaction as an argument to drop_one_dir_item()
and its helpers (link_to_fixup_dir() and unlink_inode_for_log_replay()),
pass the walk_control structure as we can access the transaction from it
and the subvolume root. This is going to be needed by an incoming change
that improves error reporting for log replay and also reduces the number
of arguments passed to link_to_fixup_dir().
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 passing the transaction and subvolume root and log tree as
arguments, pass the walk_control structure as we can grab all of those
from the structure. This reduces the number of arguments passed and it's
going to be needed by an incoming change that improves error reporting
for log replay.
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 passing the transaction, subvolume root and log tree as
arguments to add_inode_ref() and its helpers (__add_inode_ref(),
unlink_refs_not_in_log(), unlink_extrefs_not_in_log() and
unlink_old_inode_refs()), pass the walk_control structure as we can
access all of those from the structure. This reduces the number of
arguments passed and it's going to be needed by an incoming change
that improves error reporting for log replay.
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 passing the transaction and subvolume root as arguments to
replay_one_extent(), pass the walk_control structure as we can grab all
of those from the structure. This reduces the number of arguments passed
and it's going to be needed by an incoming change that improves error
reporting for log replay.
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 passing the transaction and log tree as arguments to
check_item_in_log(), pass the walk_control structure as we can grab those
from the structure. This reduces the number of arguments passed and it's
going to be needed by an incoming change that improves error reporting for
log replay. Notice that a NULL log root argument to check_item_in_log()
makes it unconditionally delete a directory entry, so since the
walk_control always has a non-NULL log root, we add an extra boolean to
check_item_in_log() to tell it if it should unconditionally delete a
directory entry, preserving the behaviour and also making it a bit more
clear.
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 passing the transaction, subvolume root and log tree as
arguments to replay_dir_deletes(), pass the walk_control structure as
we can grab all of those from the structure. This reduces the number of
arguments passed and it's going to be needed by an incoming change that
improves error reporting for log replay. This also requires changing
fixup_inode_link_counts() and fixup_inode_link_count() to take that
structure as an argument since fixup_inode_link_count() makes a call
to replay_dir_deletes().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In upcoming changes we need to pass struct walk_control as an argument to
replay_dir_deletes() and link_to_fixup_dir() so we need to move its
definition above the prototypes of those functions. So move it up right
below the enum that defines log replay stages and before any functions and
function prototypes are declared. Also fixup the comments while moving it
so that they comply with the preferred code style (capitalize the first
word in a sentence, end sentences with punctuation, makes lines wider and
closer to the 80 characters limit).
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 passing the transaction, subvolume root and log tree as
arguments to replay_xattr_deletes(), pass the walk_control structure as
we can grab all of those from the structure. This reduces the number of
arguments passed and it's going to be needed by an incoming change that
improves error reporting for log replay.
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 have this odd behaviour:
1) At btrfs_replay_log() we drop the reference of the log root tree if
the call to btrfs_recover_log_trees() failed;
2) But if the call to btrfs_recover_log_trees() did not fail, we don't
drop the reference in btrfs_replay_log() - we expect that
btrfs_recover_log_trees() does it in case it returns success.
Let's simplify this and make btrfs_replay_log() always drop the reference
on the log root tree, not only this simplifies code as it's what makes
sense since it's btrfs_replay_log() who grabbed the reference in the first
place.
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 setting log_root_tree->log_root to NULL as this is
already NULL, we never assigned anything to it before and it's meaningless
as a log root never has a value other than NULL for the ->log_root field,
that can be not NULL only for non log roots.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's unncessary to pass a transaction parameter since struct walk_control
already has a member that points to the transaction, so we can make the
functions access the structure.
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 duplicating the dropping of a log tree in case we jump to the
'error' label, move the dropping under the 'error' label and get rid of the
the unnecessary setting of the log root to NULL since we return immediately
after.
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 passing an extra log root parameter for the log tree walk
functions and callbacks, add the log tree to struct walk_control and
make those functions and callbacks extract the log root from that
structure, reducing the number of parameters. This also simplifies
further upcoming changes to report log tree replay failures.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Everywhere we have a log root we name it as 'log' or 'log_root' except in
walk_down_log_tree() and walk_up_log_tree() where we name it as 'root',
which not only it's inconsistent, it's also confusing since we typically
use 'root' when naming variables that refer to a subvolume tree. So for
clairty and consistency rename the 'root' argument to 'log'.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Everywhere else we refer to a subvolume root we are replaying to simply
as 'root', so rename from 'replay_dest' to 'root' for consistency and
having a more meaningful and shorter name. While at it also update the
comment to be more detailed and comply to preferred style (first word in
a sentence is capitalized and sentence ends with punctuation).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The 'free' and 'pin' member of struct walk_control, used during log replay
and when freeing a log tree, are defined as integers but in practice are
used as booleans. Change their type to bool and while at it update their
comments to be more detailed and comply with the preferred comment style
(first word in a sentence is capitalized, sentences end with punctuation
and the comment opening (/*) is on a line of its own).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Inside btrfs_fs_info we cache several bits shift like sectorsize_bits.
Apply this to max and min folio orders so that every time mapping order
needs to be applied we can skip the calculation.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently if we want to iterate all blocks inside a bio, we do something
like this:
bio_for_each_segment_all(bvec, bio, iter_all) {
for (off = 0; off < bvec->bv_len; off += sectorsize) {
/* Iterate blocks using bv + off */
}
}
That's fine for now, but it will not handle future bs > ps, as
bio_for_each_segment_all() is a single-page iterator, it will always
return a bvec that's no larger than a page.
But for bs > ps cases, we need a full folio (which covers at least one
block) so that we can work on the block.
To address this problem and handle future bs > ps cases better:
- Introduce a helper btrfs_bio_for_each_block_all()
This helper will create a local bvec_iter, which has the size of the
target bio. Then grab the current physical address of the current
location, then advance the iterator by block size.
- Use btrfs_bio_for_each_block_all() to replace existing call sites
Including:
* set_bio_pages_uptodate() in raid56
* verify_bio_data_sectors() in raid56
Both will result much easier to read code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently if we want to iterate a bio in block unit, we do something
like this:
while (iter->bi_size) {
struct bio_vec bv = bio_iter_iovec();
/* Do something with using the bv */
bio_advance_iter_single(&bbio->bio, iter, sectorsize);
}
That's fine for now, but it will not handle future bs > ps, as
bio_iter_iovec() returns a single-page bvec, meaning the bv_len will not
exceed page size.
This means the code using that bv can only handle a block if bs <= ps.
To address this problem and handle future bs > ps cases better:
- Introduce a helper btrfs_bio_for_each_block()
Instead of bio_vec, which has single and multiple page version and
multiple page version has quite some limits, use my favorite way to
represent a block, phys_addr_t.
For bs <= ps cases, nothing is changed, except we will do a very
small overhead to convert phys_addr_t to a folio, then use the proper
folio helpers to handle the possible highmem cases.
For bs > ps cases, all blocks will be backed by large folios, meaning
every folio will cover at least one block. And still use proper folio
helpers to handle highmem cases.
With phys_addr_t, we will handle both large folio and highmem
properly. So there is no better single variable to present a btrfs
block than phys_addr_t.
- Extract the data block csum calculation into a helper
The new helper, btrfs_calculate_block_csum() will be utilized by
btrfs_csum_one_bio().
- Use btrfs_bio_for_each_block() to replace existing call sites
Including:
* index_one_bio() from raid56.c
Very straight-forward.
* btrfs_check_read_bio()
Also update repair_one_sector() to grab the folio using phys_addr_t,
and do extra checks to make sure the folio covers at least one
block.
We do not need to bother bv_len at all now.
* btrfs_csum_one_bio()
Now we can move the highmem handling into a dedicated helper,
calculate_block_csum(), and use btrfs_bio_for_each_block() helper.
There is one exception in btrfs_decompress_buf2page(), which is copying
decompressed data into the original bio, which is not iterating using
block size thus we don't need to bother.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently for btrfs checksum verification, we do it in the following
pattern:
kaddr = kmap_local_*();
ret = btrfs_check_csum_csum(kaddr);
kunmap_local(kaddr);
It's OK for now, but it's still not following the patterns of helpers
inside linux/highmem.h, which never requires a virt memory address.
In those highmem helpers, they mostly accept a folio, some offset/length
inside the folio, and in the implementation they check if the folio
needs partial kmap, and do the handling.
Inspired by those formal highmem helpers, enhance the highmem handling
of data checksum verification by:
- Rename btrfs_check_sector_csum() to btrfs_check_block_csum()
To follow the more common term "block" used in all other major
filesystems.
- Pass a physical address into btrfs_check_block_csum() and
btrfs_data_csum_ok()
The physical address is always available even for a highmem page.
Since it's page frame number << PAGE_SHIFT + offset in page.
And with that physical address, we can grab the folio covering the
page, and do extra checks to ensure it covers at least one block.
This also allows us to do the kmap inside btrfs_check_block_csum().
This means all the extra HIGHMEM handling will be concentrated into
btrfs_check_block_csum(), and no callers will need to bother highmem
by themselves.
- Properly zero out the block if csum mismatch
Since btrfs_data_csum_ok() only got a paddr, we can not and should not
use memzero_bvec(), which only accepts single page bvec.
Instead use paddr to grab the folio and call folio_zero_range()
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently if block size < page size, btrfs only supports one single
config, 4K.
This is mostly to reduce the test configurations, as 4K is going to be
the default block size for all architectures.
However all other major filesystems have no artificial limits on the
support block size, and some are already supporting block size > page
sizes.
Since the btrfs subpage block support has been there for a long time,
it's time for us to enable all block size <= page size support.
So here enable all block sizes support as long as it's no larger than
page size for experimental builds.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Replace max_t() followed by min_t() with a single clamp().
As was pointed by David Laight in
https://lore.kernel.org/linux-btrfs/20250906122458.75dfc8f0@pumpkin/
the calculation may overflow u32 when the input value is too large, so
clamp_t() is not used. In practice the expected values are in range of
megabytes to gigabytes (throughput limit) so the bug would not happen.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
[ Use clamp() and add explanation. ]
Signed-off-by: David Sterba <dsterba@suse.com>
Annual typo fixing pass. Strangely codespell found only about 30% of
what is in this patch, the rest was done manually using text
spellchecker with a custom dictionary of acceptable terms.
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the compression workspace buffer size is always based on
PAGE_SIZE, but btrfs has support subpage sized block size for some time.
This means for one-shot compression algorithm like lzo, we're wasting
quite some memory if the block size is smaller than page size, as the
LZO only works on one block (thus one-shot).
On 64K page sized systems with 4K block size, it means we only need at
most 8K buffer space for lzo, but in reality we're allocating 64K
buffer.
So to reduce the memory usage, change all workspace buffer to base its
size based on block size other than page size.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since all workspace managers are per-fs, there is no need nor no way to
store them inside btrfs_compress_op::wsm anymore.
With that said, we can do the following modifications:
- Remove zstd_workspace_mananger::ops
Zstd always grab the global btrfs_compress_op[].
- Remove btrfs_compress_op::wsm member
- Rename btrfs_compress_op to btrfs_compress_levels
This should make it more clear that btrfs_compress_levels structures are
only to indicate the levels of each compress algorithm.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since all workspaces are handled by the per-fs workspace managers, we
can safely remove the old per-module managers.
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 several interfaces involved for each algorithm:
- alloc workspace
All algorithms allocate a workspace without the need for workspace
manager.
So no change needs to be done.
- get workspace
This involves checking the workspace manager to find a free one, and
if not, allocate a new one.
For none and lzo, they share the same generic btrfs_get_workspace()
helper, only needs to update that function to use the per-fs manager.
For zlib it uses a wrapper around btrfs_get_workspace(), so no special
work needed.
For zstd, update zstd_find_workspace() and zstd_get_workspace() to
utilize the per-fs manager.
- put workspace
For none/zlib/lzo they share the same btrfs_put_workspace(), update
that function to use the per-fs manager.
For zstd, it's zstd_put_workspace(), the same update.
- zstd specific timer
This is the timer to reclaim workspace, change it to grab the per-fs
workspace manager instead.
Now all workspace are managed by the per-fs manager.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This involves:
- Add (alloc|free)_workspace_manager helpers.
These are the helper to alloc/free workspace_manager structure.
The allocator will allocate a workspace_manager structure, initialize
it, and pre-allocate one workspace for it.
The freer will do the cleanup and set the manager pointer to NULL.
- Call alloc_workspace_manager() inside btrfs_alloc_compress_wsm()
- Call alloc_workspace_manager() inside btrfs_free_compress_wsm()
For none, zlib and lzo compression algorithms.
For now the generic per-fs workspace managers won't really have any effect,
and all compression is still going through the global workspace manager.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This involves:
- Add zstd_alloc_workspace_manager() and zstd_free_workspace_manager()
Those two functions will accept an fs_info pointer, and alloc/free
fs_info->compr_wsm[BTRFS_COMPRESS_ZSTD] pointer.
- Add btrfs_alloc_compress_wsm() and btrfs_free_compress_wsm()
Those are helpers allocating the workspace managers for all
algorithms.
For now only zstd is supported, and the timing is a little unusual,
the btrfs_alloc_compress_wsm() should only be called after the
sectorsize being initialized.
Meanwhile btrfs_free_fs_info_compress() is called in
btrfs_free_fs_info().
- Move the definition of btrfs_compression_type to "fs.h"
The reason is that "compression.h" has already included "fs.h", thus
we can not just include "compression.h" to get the definition of
BTRFS_NR_COMPRESS_TYPES to define fs_info::compr_wsm[].
For now the per-fs zstd workspace manager won't really have any effect,
and all compression is still going through the global workspace manager.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BACKGROUND]
Currently btrfs shares workspaces and their managers for all filesystems,
this is mostly fine as all those workspaces are using page size based
buffers, and btrfs only support block size (bs) <= page size (ps).
This means even if bs < ps, we at most waste some buffer space in the
workspace, but everything will still work fine.
The problem here is that is limiting our support for bs > ps cases.
As now a workspace now may need larger buffer to handle bs > ps cases,
but since the pool has no way to distinguish different workspaces, a
regular workspace (which is still using buffer size based on ps) can be
passed to a btrfs whose bs > ps.
In that case the buffer is not large enough, and will cause various
problems.
[ENHANCEMENT]
To prepare for the per-fs workspace migration, add an fs_info parameter
to all workspace related functions.
For now this new fs_info parameter is not yet utilized.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a very low chance that DEBUG_WARN() inside
btrfs_writepage_cow_fixup() can be triggered when
CONFIG_BTRFS_EXPERIMENTAL is enabled.
This only happens after run_delalloc_nocow() failed.
Unfortunately I haven't hit it for a while thus no real world dmesg for
now.
[CAUSE]
There is a race window where after run_delalloc_nocow() failed, error
handling can race with writeback thread.
Before we hit run_delalloc_nocow(), there is an inode with the following
dirty pages: (4K page size, 4K block size, no large folio)
0 4K 8K 12K 16K
|/////////|///////////|///////////|////////////|
The inode also have NODATACOW flag, and the above dirty range will go
through different extents during run_delalloc_range():
0 4K 8K 12K 16K
| NOCOW | COW | COW | NOCOW |
The race happen like this:
writeback thread A | writeback thread B
----------------------------------+--------------------------------------
Writeback for folio 0 |
run_delalloc_nocow() |
|- nocow_one_range() |
| For range [0, 4K), ret = 0 |
| |
|- fallback_to_cow() |
| For range [4K, 8K), ret = 0 |
| Folio 4K *UNLOCKED* |
| | Writeback for folio 4K
|- fallback_to_cow() | extent_writepage()
| For range [8K, 12K), failure | |- writepage_delalloc()
| | |
|- btrfs_cleanup_ordered_extents()| |
|- btrfs_folio_clear_ordered() | |
| Folio 0 still locked, safe | |
| | | Ordered extent already allocated.
| | | Nothing to do.
| | |- extent_writepage_io()
| | |- btrfs_writepage_cow_fixup()
|- btrfs_folio_clear_ordered() | |
Folio 4K hold by thread B, | |
UNSAFE! | |- btrfs_test_ordered()
| | Cleared by thread A,
| |
| |- DEBUG_WARN();
This is only possible after run_delalloc_nocow() failure, as
cow_file_range() will keep all folios and io tree range locked, until
everything is finished or after error handling.
The root cause is we allow fallback_to_cow() and nocow_one_range() to
unlock the folios after a successful run, so that during error handling
we're no longer safe to use btrfs_cleanup_ordered_extents() as the
folios are already unlocked.
[FIX]
- Make fallback_to_cow() and nocow_one_range() to keep folios locked
after a successful run
For fallback_to_cow() we can pass COW_FILE_RANGE_KEEP_LOCKED flag
into cow_file_range().
For nocow_one_range() we have to remove the PAGE_UNLOCK flag from
extent_clear_unlock_delalloc().
- Unlock folios if everything is fine in run_delalloc_nocow()
- Use extent_clear_unlock_delalloc() to handle range [@start,
@cur_offset) inside run_delalloc_nocow()
Since folios are still locked, we do not need
cleanup_dirty_folios() to do the cleanup.
extent_clear_unlock_delalloc() with "PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK" will clear the dirty flags.
- Remove cleanup_dirty_folios()
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently if we hit an error inside nocow_one_range(), we do not clear
the page dirty, and let the caller to handle it.
This is very different compared to fallback_to_cow(), when that function
failed, everything will be cleaned up by cow_file_range().
Enhance the situation by:
- Use a common error handling for nocow_one_range()
If we failed anything, use the same btrfs_cleanup_ordered_extents()
and extent_clear_unlock_delalloc().
btrfs_cleanup_ordered_extents() is safe even if we haven't created new
ordered extent, in that case there should be no OE and that function
will do nothing.
The same applies to extent_clear_unlock_delalloc(), and since we're
passing PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK, it
will also clear folio dirty flag during error handling.
- Avoid touching the failed range of nocow_one_range()
As the failed range will be cleaned up and unlocked by that function.
Here we introduce a new variable @nocow_end to record the failed range,
so that we can skip it during the error handling of run_delalloc_nocow().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When running emulated write error tests like generic/475, we can hit
error messages like this:
BTRFS error (device dm-12 state EA): run_delalloc_nocow failed, root=596 inode=264 start=1605632 len=73728: -5
BTRFS error (device dm-12 state EA): failed to run delalloc range, root=596 ino=264 folio=1605632 submit_bitmap=0-7 start=1605632 len=73728: -5
Which is normally buried by direct IO error messages.
However above error messages are not enough to determine which is the
real range that caused the error.
Considering we can have multiple different extents in one delalloc
range (e.g. some COW extents along with some NOCOW extents), just
outputting the error at the end of run_delalloc_nocow() is not enough.
To enhance the error messages:
- Remove the rate limit on the existing error messages
In the generic/475 example, most error messages are from direct IO,
not really from the delalloc range.
Considering how useful the delalloc range error messages are, we don't
want they to be rate limited.
- Add extra @cur_offset output for cow_file_range()
- Add extra variable output for run_delalloc_nocow()
This is especially important for run_delalloc_nocow(), as there
are extra error paths where we can hit error without into
nocow_one_range() nor fallback_to_cow().
- Add an error message for nocow_one_range()
That's the missing part.
For fallback_to_cow(), we have error message from cow_file_range()
already.
- Constify the @len and @end local variables for nocow_one_range()
This makes it much easier to make sure @len and @end are not modified
at runtime.
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>
Commit 79525b51ac ("io_uring: fix nvme's 32b cqes on mixed cq") split
out a separate io_uring_cmd_done32() helper for ->uring_cmd()
implementations that return 32-byte CQEs. The res2 value passed to
io_uring_cmd_done() is now unused because __io_uring_cmd_done() ignores
it when is_cqe32 is passed as false. So drop the parameter from
io_uring_cmd_done() to simplify the callers and clarify that it's not
possible to return an extra value beyond the 32-bit CQE result.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently the error handling of run_delalloc_nocow() modifies
@cur_offset to handle different parts of the delalloc range.
However the error handling can always be split into 3 parts:
1) The range with ordered extents allocated (OE cleanup)
We have to cleanup the ordered extents and unlock the folios.
2) The range that have been cleaned up (skip)
For now it's only for the range of fallback_to_cow().
We should not touch it at all.
3) The range that is not yet touched (untouched)
We have to unlock the folios and clear any reserved space.
This 3 ranges split has the same principle as cow_file_range(), however
the NOCOW/COW handling makes the above 3 range split much more complex:
a) Failure immediately after a successful OE allocation
Thus no @cow_start nor @cow_end set.
start cur_offset end
| OE cleanup | untouched |
b) Failure after hitting a COW range but before calling
fallback_to_cow()
start cow_start cur_offset end
| OE Cleanup | untouched |
c) Failure to call fallback_to_cow()
start cow_start cow_end end
| OE Cleanup | skip | untouched |
Instead of modifying @cur_offset, do proper range calculation for
OE-cleanup and untouched ranges using above 3 cases with proper range
charts.
This avoid updating @cur_offset, as it will an extra output for debug
purposes later, and explain the behavior easier.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The ref_tracker infrastructure aids debugging but is not enabled by
default as it has a performance impact. Add mount option 'ref_tracker'
so it can be selectively enabled on a filesystem. Currently it track
references of 'delayed inodes'.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are seeing soft lockups in kill_all_delayed_nodes due to a
delayed_node with a lingering reference count of 1. Printing at this
point will reveal the guilty stack trace. If the delayed_node has no
references there should be no output.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add ref_tracker infrastructure for struct btrfs_delayed_node.
It is a response to the largest btrfs related crash in our fleet. We're
seeing soft lockups in btrfs_kill_all_delayed_nodes() that seem to be a
result of delayed_nodes not being released properly.
A ref_tracker object is allocated on reference count increases and freed
on reference count decreases. The ref_tracker object stores a stack
trace of where it is allocated. The ref_tracker_dir object is embedded
in btrfs_delayed_node and keeps track of all current and some old/freed
ref_tracker objects. When a leak is detected we can print the stack
traces for all ref_trackers that have not yet been freed.
Here is a common example of taking a reference to a delayed_node and
freeing it with ref_tracker.
struct btrfs_ref_tracker tracker;
struct btrfs_delayed_node *node;
node = btrfs_get_delayed_node(inode, &tracker);
// use delayed_node...
btrfs_release_delayed_node(node, &tracker);
There are two special cases where the delayed_node reference is "long
lived", meaning that the thread that takes the reference and the thread
that releases the reference are different. The 'inode_cache_tracker'
tracks the delayed_node stored in btrfs_inode. The 'node_list_tracker'
tracks the delayed_node stored in the btrfs_delayed_root
node_list/prepare_list. These trackers are embedded in the
btrfs_delayed_node.
btrfs_ref_tracker and btrfs_ref_tracker_dir are wrappers that either
compile to the corresponding ref_tracker structs or empty structs
depending on CONFIG_BTRFS_DEBUG. There are also btrfs wrappers for
the ref_tracker API.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're almost done cleaning misused int/bool parameters. Convert a bunch
of them, found by manual grepping. Note that btrfs_sync_fs() needs an
int as it's mandated by the struct super_operations prototype.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove CONFIG_BTRFS_FS_REF_VERIFY Kconfig and add it as part of
CONFIG_BTRFS_DEBUG. This should not be impactful to the performance
of debug. The struct btrfs_ref takes an additional u64, btrfs_fs_info
takes an additional spinlock_t and rb_root. All of the ref_verify logic
is still protected by a mount option.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the standard error pointer macro to simplify the code.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: Xichao Zhao <zhao.xichao@vivo.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>
[BEHAVIOR DIFFERENCE BETWEEN COMPRESSION ALGOS]
Currently LZO compression algorithm will check if we're making the
compressed data larger after compressing more than 2 blocks.
But zlib and zstd do the same checks after compressing more than 8192
bytes.
This is not a big deal, but since we're already supporting larger block
size (e.g. 64K block size if page size is also 64K), this check is not
suitable for all block sizes.
For example, if our page and block size are both 16KiB, and after the
first block compressed using zlib, the resulted compressed data is
slightly larger than 16KiB, we will immediately abort the compression.
This makes zstd and zlib compression algorithms to behave slightly
different from LZO, which only aborts after compressing two blocks.
[ENHANCEMENT]
To unify the behavior, only abort the compression after compressing at
least two blocks.
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>
For the 3 supported compression algorithms, two of them (zstd and zlib)
are already grabbing the btrfs inode for error messages.
It's more common to pass btrfs_inode and grab the address space from it.
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 hint block group selection in the extent allocator is wrong in the
first place, as it can select the dedicated data relocation block group for
the normal data allocation.
Since we separated the normal data space_info and the data relocation
space_info, we can easily identify a block group is for data relocation or
not. Do not choose it for the normal data allocation.
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>
If you run a workload with:
- a cgroup that does tons of parallel data reading, with a working set
much larger than its memory limit
- a second cgroup that writes relatively fewer files, with overwrites,
with no memory limit
(see full code listing at the bottom for a reproducer)
Then what quickly occurs is:
- we have a large number of threads trying to read the csum tree
- we have a decent number of threads deleting csums running delayed refs
- we have a large number of threads in direct reclaim and thus high
memory pressure
The result of this is that we writeback the csum tree repeatedly mid
transaction, to get back the extent_buffer folios for reclaim. As a
result, we repeatedly COW the csum tree for the delayed refs that are
deleting csums. This means repeatedly write locking the higher levels of
the tree.
As a result of this, we achieve an unpleasant priority inversion. We
have:
- a high degree of contention on the csum root node (and other upper
nodes) eb rwsem
- a memory starved cgroup doing tons of reclaim on CPU.
- many reader threads in the memory starved cgroup "holding" the sem
as readers, but not scheduling promptly. i.e., task __state == 0, but
not running on a cpu.
- btrfs_commit_transaction stuck trying to acquire the sem as a writer.
(running delayed_refs, deleting csums for unreferenced data extents)
This results in arbitrarily long transactions. This then results in
seriously degraded performance for any cgroup using the filesystem (the
victim cgroup in the script).
It isn't an academic problem, as we see this exact problem in production
at Meta with one cgroup over its memory limit ruining btrfs performance
for the whole system, stalling critical system services that depend on
btrfs syncs.
The underlying scheduling "problem" with global rwsems is sort of thorny
and apparently well known and was discussed at LPC 2024, for example.
As a result, our main lever in the short term is just trying to reduce
contention on our various rwsems with an eye to reducing the frequency
of write locking, to avoid disabling the read lock fast acquisition path.
Luckily, it seems likely that many reads are for old extents written
many transactions ago, and that for those we *can* in fact search the
commit root. The commit_root_sem only gets taken write once, near the
end of transaction commit, no matter how much memory pressure there is,
so we have much less contention between readers and writers.
This change detects when we are trying to read an old extent (according
to extent map generation) and then wires that through bio_ctrl to the
btrfs_bio, which unfortunately isn't allocated yet when we have this
information. When we go to lookup the csums in lookup_bio_sums we can
check this condition on the btrfs_bio and do the commit root lookup
accordingly.
Note that a single bio_ctrl might collect a few extent_maps into a single
bio, so it is important to track a maximum generation across all the
extent_maps used for each bio to make an accurate decision on whether it
is valid to look in the commit root. If any extent_map is updated in the
current generation, we can't use the commit root.
To test and reproduce this issue, I used the following script and
accompanying C program (to avoid bottlenecks in constantly forking
thousands of dd processes):
====== big-read.c ======
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#define BUF_SZ (128 * (1 << 10UL))
int read_once(int fd, size_t sz) {
char buf[BUF_SZ];
size_t rd = 0;
int ret = 0;
while (rd < sz) {
ret = read(fd, buf, BUF_SZ);
if (ret < 0) {
if (errno == EINTR)
continue;
fprintf(stderr, "read failed: %d\n", errno);
return -errno;
} else if (ret == 0) {
break;
} else {
rd += ret;
}
}
return rd;
}
int read_loop(char *fname) {
int fd;
struct stat st;
size_t sz = 0;
int ret;
while (1) {
fd = open(fname, O_RDONLY);
if (fd == -1) {
perror("open");
return 1;
}
if (!sz) {
if (!fstat(fd, &st)) {
sz = st.st_size;
} else {
perror("stat");
return 1;
}
}
ret = read_once(fd, sz);
close(fd);
}
}
int main(int argc, char *argv[]) {
int fd;
struct stat st;
off_t sz;
char *buf;
int ret;
if (argc != 2) {
fprintf(stderr, "Usage: %s <filename>\n", argv[0]);
return 1;
}
return read_loop(argv[1]);
}
====== repro.sh ======
#!/usr/bin/env bash
SCRIPT=$(readlink -f "$0")
DIR=$(dirname "$SCRIPT")
dev=$1
mnt=$2
shift
shift
CG_ROOT=/sys/fs/cgroup
BAD_CG=$CG_ROOT/bad-nbr
GOOD_CG=$CG_ROOT/good-nbr
NR_BIGGOS=1
NR_LITTLE=10
NR_VICTIMS=32
NR_VILLAINS=512
START_SEC=$(date +%s)
_elapsed() {
echo "elapsed: $(($(date +%s) - $START_SEC))"
}
_stats() {
local sysfs=/sys/fs/btrfs/$(findmnt -no UUID $dev)
echo "================"
date
_elapsed
cat $sysfs/commit_stats
cat $BAD_CG/memory.pressure
}
_setup_cgs() {
echo "+memory +cpuset" > $CG_ROOT/cgroup.subtree_control
mkdir -p $GOOD_CG
mkdir -p $BAD_CG
echo max > $BAD_CG/memory.max
# memory.high much less than the working set will cause heavy reclaim
echo $((1 << 30)) > $BAD_CG/memory.high
# victims get a subset of villain CPUs
echo 0 > $GOOD_CG/cpuset.cpus
echo 0,1,2,3 > $BAD_CG/cpuset.cpus
}
_kill_cg() {
local cg=$1
local attempts=0
echo "kill cgroup $cg"
[ -f $cg/cgroup.procs ] || return
while true; do
attempts=$((attempts + 1))
echo 1 > $cg/cgroup.kill
sleep 1
procs=$(wc -l $cg/cgroup.procs | cut -d' ' -f1)
[ $procs -eq 0 ] && break
done
rmdir $cg
echo "killed cgroup $cg in $attempts attempts"
}
_biggo_vol() {
echo $mnt/biggo_vol.$1
}
_biggo_file() {
echo $(_biggo_vol $1)/biggo
}
_subvoled_biggos() {
total_sz=$((10 << 30))
per_sz=$((total_sz / $NR_VILLAINS))
dd_count=$((per_sz >> 20))
echo "create $NR_VILLAINS subvols with a file of size $per_sz bytes for a total of $total_sz bytes."
for i in $(seq $NR_VILLAINS)
do
btrfs subvol create $(_biggo_vol $i) &>/dev/null
dd if=/dev/zero of=$(_biggo_file $i) bs=1M count=$dd_count &>/dev/null
done
echo "done creating subvols."
}
_setup() {
[ -f .done ] && rm .done
findmnt -n $dev && exit 1
if [ -f .re-mkfs ]; then
mkfs.btrfs -f -m single -d single $dev >/dev/null || exit 2
else
echo "touch .re-mkfs to populate the test fs"
fi
mount -o noatime $dev $mnt || exit 3
[ -f .re-mkfs ] && _subvoled_biggos
_setup_cgs
}
_my_cleanup() {
echo "CLEANUP!"
_kill_cg $BAD_CG
_kill_cg $GOOD_CG
sleep 1
umount $mnt
}
_bad_exit() {
_err "Unexpected Exit! $?"
_stats
exit $?
}
trap _my_cleanup EXIT
trap _bad_exit INT TERM
_setup
# Use a lot of page cache reading the big file
_villain() {
local i=$1
echo $BASHPID > $BAD_CG/cgroup.procs
$DIR/big-read $(_biggo_file $i)
}
# Hit del_csum a lot by overwriting lots of small new files
_victim() {
echo $BASHPID > $GOOD_CG/cgroup.procs
i=0;
while (true)
do
local tmp=$mnt/tmp.$i
dd if=/dev/zero of=$tmp bs=4k count=2 >/dev/null 2>&1
i=$((i+1))
[ $i -eq $NR_LITTLE ] && i=0
done
}
_one_sync() {
echo "sync..."
before=$(date +%s)
sync
after=$(date +%s)
echo "sync done in $((after - before))s"
_stats
}
# sync in a loop
_sync() {
echo "start sync loop"
syncs=0
echo $BASHPID > $GOOD_CG/cgroup.procs
while true
do
[ -f .done ] && break
_one_sync
syncs=$((syncs + 1))
[ -f .done ] && break
sleep 10
done
if [ $syncs -eq 0 ]; then
echo "do at least one sync!"
_one_sync
fi
echo "sync loop done."
}
_sleep() {
local time=${1-60}
local now=$(date +%s)
local end=$((now + time))
while [ $now -lt $end ];
do
echo "SLEEP: $((end - now))s left. Sleep 10."
sleep 10
now=$(date +%s)
done
}
echo "start $NR_VILLAINS villains"
for i in $(seq $NR_VILLAINS)
do
_villain $i &
disown # get rid of annoying log on kill (done via cgroup anyway)
done
echo "start $NR_VICTIMS victims"
for i in $(seq $NR_VICTIMS)
do
_victim &
disown
done
_sync &
SYNC_PID=$!
_sleep $1
_elapsed
touch .done
wait $SYNC_PID
echo "OK"
exit 0
Without this patch, that reproducer:
- Ran for 6+ minutes instead of 60s
- Hung hundreds of threads in D state on the csum reader lock
- Got a commit stuck for 3 minutes
sync done in 388s
================
Wed Jul 9 09:52:31 PM UTC 2025
elapsed: 420
commits 2
cur_commit_ms 0
last_commit_ms 159446
max_commit_ms 159446
total_commit_ms 160058
some avg10=99.03 avg60=98.97 avg300=75.43 total=418033386
full avg10=82.79 avg60=80.52 avg300=59.45 total=324995274
419 hits state R, D comms big-read
btrfs_tree_read_lock_nested
btrfs_read_lock_root_node
btrfs_search_slot
btrfs_lookup_csum
btrfs_lookup_bio_sums
btrfs_submit_bbio
1 hits state D comms btrfs-transacti
btrfs_tree_lock_nested
btrfs_lock_root_node
btrfs_search_slot
btrfs_del_csums
__btrfs_run_delayed_refs
btrfs_run_delayed_refs
With the patch, the reproducer exits naturally, in 65s, completing a
pretty decent 4 commits, despite heavy memory pressure. Occasionally you
can still trigger a rather long commit (couple seconds) but never one
that is minutes long.
sync done in 3s
================
elapsed: 65
commits 4
cur_commit_ms 0
last_commit_ms 485
max_commit_ms 689
total_commit_ms 2453
some avg10=98.28 avg60=64.54 avg300=19.39 total=64849893
full avg10=74.43 avg60=48.50 avg300=14.53 total=48665168
some random rwalker samples showed the most common stack in reclaim,
rather than the csum tree:
145 hits state R comms bash, sleep, dd, shuf
shrink_folio_list
shrink_lruvec
shrink_node
do_try_to_free_pages
try_to_free_mem_cgroup_pages
reclaim_high
Link: https://lpc.events/event/18/contributions/1883/
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
In messages.h there's linux/types.h included more than once.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=22939
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that btrfs_zone_finish_endio_workfn() is directly calling
do_zone_finish() the only caller of btrfs_zone_finish_endio() is
btrfs_finish_one_ordered().
btrfs_finish_one_ordered() already has error handling in-place so
btrfs_zone_finish_endio() can return an error if the block group lookup
fails.
Also as btrfs_zone_finish_endio() already checks for zoned filesystems and
returns early, there's no need to do this in the caller.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When btrfs_zone_finish_endio_workfn() is calling btrfs_zone_finish_endio()
it already has a pointer to the block group. Furthermore
btrfs_zone_finish_endio() does additional checks if the block group can be
finished or not.
But in the context of btrfs_zone_finish_endio_workfn() only the actual
call to do_zone_finish() is of interest, as the skipping condition when
there is still room to allocate from the block group cannot be checked.
Directly call do_zone_finish() on the block group.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's one only one caller of unaccount_log_buffer() and both this
function and the caller are short, so move its code into the caller.
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>
Instead of extracting again the disk_bytenr and disk_num_bytes values from
the file extent item to pass to btrfs_qgroup_trace_extent(), use the key
local variable 'ins' which already has those values, reducing the size of
the source code.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of having an if statement to check for regular and prealloc
extents first, process them in a block, and then following with an else
statement to check for an inline extent, check for an inline extent first,
process it and jump to the 'update_inode' label, allowing us to avoid
having the code for processing regular and prealloc extents inside a
block, reducing the high indentation level by one and making the code
easier to read and avoid line splittings too.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At replay_one_extent(), we can jump to the code that updates the file
extent range and updates the inode when processing a file extent item that
represents a hole and we don't have the NO_HOLES feature enabled. This
helps reduce the high indentation level by one in replay_one_extent() and
avoid splitting some lines to make the code easier to read.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the replay_one_buffer() log tree walk callback we return errors to the
log tree walk caller and then the caller aborts the transaction, if we
have one, or turns the fs into error state if we don't have one. While
this reduces code it makes it harder to figure out where exactly an error
came from. So add the transaction aborts after every failure inside the
replay_one_buffer() callback and the functions it calls, making it as
fine grained as possible, so that it helps figuring out why failures
happen.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If read_alloc_one_name() we explicitly return -ENOMEM and currently that
is fine since it's the only error read_alloc_one_name() can return for
now. However this is fragile and not future proof, so return instead what
read_alloc_one_name() returned.
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>
Instead of keep dereferencing the walk_control structure to extract the
transaction handle whenever is needed, do it once by storing it in a local
variable and then use the variable everywhere. This reduces code verbosity
and eliminates the need for some split lines.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the process_one_buffer() log tree walk callback we return errors to the
log tree walk caller and then the caller aborts the transaction, if we
have one, or turns the fs into error state if we don't have one. While
this reduces code it makes it harder to figure out where exactly an error
came from. So add the transaction aborts after every failure inside the
process_one_buffer() callback, so that it helps figuring out why failures
happen.
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>
We do several things while walking a log tree (for replaying and for
freeing a log tree) like reading extent buffers and cleaning them up,
but we don't immediately abort the transaction, or turn the fs into an
error state, when one of these things fails. Instead we the transaction
abort or turn the fs into error state in the caller of the entry point
function that walks a log tree - walk_log_tree() - which means we don't
get to know exactly where an error came from.
Improve on this by doing a transaction abort / turn fs into error state
after each such failure so that when it happens we have a better
understanding where the failure comes from. This deliberately leaves
the transaction abort / turn fs into error state in the callers of
walk_log_tree() as to ensure we don't get into an inconsistent state in
case we forget to do it deeper in call chain. It also deliberately does
not do it after errors from the calls to the callback defined in
struct walk_control::process_func(), as we will do it later on another
patch.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function cow_file_range() has two boolean parameters. Replace it
with a single @flags parameter, with two flags:
- COW_FILE_RANGE_NO_INLINE
- COW_FILE_RANGE_KEEP_LOCKED
And since we're here, also update the comments of cow_file_range() to
replace the old "page" usage with "folio".
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull a few more btrfs fixes from David Sterba:
- in tree-checker, fix wrong size of check for inode ref item
- in ref-verify, handle combination of mount options that allow
partially damaged extent tree (reported by syzbot)
- additional validation of compression mount option to catch invalid
string as level
* tag 'for-6.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: reject invalid compression level
btrfs: ref-verify: handle damaged extent root tree
btrfs: tree-checker: fix the incorrect inode ref size check
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This patch adds a new WQ_PERCPU flag to all the fs subsystem users to
explicitly request the use of the per-CPU behavior. Both flags coexist
for one release cycle to allow callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
All existing users have been updated accordingly.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/20250916082906.77439-4-marco.crivellari@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/20250916082906.77439-2-marco.crivellari@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Inspired by recent changes to compression level parsing in
6db1df415d ("btrfs: accept and ignore compression level for lzo")
it turns out that we do not do any extra validation for compression
level input string, thus allowing things like "compress=lzo:invalid" to
be accepted without warnings.
Although we accept levels that are beyond the supported algorithm
ranges, accepting completely invalid level specification is not correct.
Fix the too loose checks for compression level, by doing proper error
handling of kstrtoint(), so that we will reject not only too large
values (beyond int range) but also completely wrong levels like
"lzo:invalid".
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Inside check_inode_ref(), we need to make sure every structure,
including the btrfs_inode_extref header, is covered by the item. But
our code is incorrectly using "sizeof(iref)", where @iref is just a
pointer.
This means "sizeof(iref)" will always be "sizeof(void *)", which is much
smaller than "sizeof(struct btrfs_inode_extref)".
This will allow some bad inode extrefs to sneak in, defeating tree-checker.
[FIX]
Fix the typo by calling "sizeof(*iref)", which is the same as
"sizeof(struct btrfs_inode_extref)", and will be the correct behavior we
want.
Fixes: 71bf92a9b8 ("btrfs: tree-checker: Add check for INODE_REF")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- in zoned mode, turn assertion to proper code when reserving space in
relocation block group
- fix search key of extended ref (hardlink) when replaying log
- fix initialization of file extent tree on filesystems without
no-holes feature
- add harmless data race annotation to block group comparator
* tag 'for-6.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: annotate block group access with data_race() when sorting for reclaim
btrfs: initialize inode::file_extent_tree after i_mode has been set
btrfs: zoned: fix incorrect ASSERT in btrfs_zoned_reserve_data_reloc_bg()
btrfs: fix invalid extref key setup when replaying dentry
generic_delete_inode() is rather misleading for what the routine is
doing. inode_just_drop() should be much clearer.
The new naming is inconsistent with generic_drop_inode(), so rename that
one as well with inode_ as the suffix.
No functional changes.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
When sorting the block group list for reclaim we are using a block group's
used bytes counter without taking the block group's spinlock, so we can
race with a concurrent task updating it (at btrfs_update_block_group()),
which makes tools like KCSAN unhappy and report a race.
Since the sorting is not strictly needed from a functional perspective
and such races should rarely cause any ordering changes (only load/store
tearing could cause them), not to mention that after the sorting the
ordering may no longer be accurate due to concurrent allocations and
deallocations of extents in a block group, annotate the accesses to the
used counter with data_race() to silence KCSAN and similar tools.
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>
btrfs_init_file_extent_tree() uses S_ISREG() to determine if the file is
a regular file. In the beginning of btrfs_read_locked_inode(), the i_mode
hasn't been read from inode item, then file_extent_tree won't be used at
all in volumes without NO_HOLES.
Fix this by calling btrfs_init_file_extent_tree() after i_mode is
initialized in btrfs_read_locked_inode().
Fixes: 3d7db6e8bd ("btrfs: don't allocate file extent tree for non regular files")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: austinchang <austinchang@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When moving a block-group to the dedicated data relocation space-info in
btrfs_zoned_reserve_data_reloc_bg() it is asserted that the newly
created block group for data relocation does not contain any
zone_unusable bytes.
But on disks with zone_capacity < zone_size, the difference between
zone_size and zone_capacity is accounted as zone_unusable.
Instead of asserting that the block-group does not contain any
zone_unusable bytes, remove them from the block-groups total size.
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Link: https://lore.kernel.org/linux-block/CAHj4cs8-cS2E+-xQ-d2Bj6vMJZ+CwT_cbdWBTju4BV35LsvEYw@mail.gmail.com/
Fixes: daa0fde322 ("btrfs: zoned: fix data relocation block group reservation")
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The offset for an extref item's key is not the object ID of the parent
dir, otherwise we would not need the extref item and would use plain ref
items. Instead the offset is the result of a hash computation that uses
the object ID of the parent dir and the name associated to the entry.
So fix this by setting the key offset at replay_one_name() to be the
result of calling btrfs_extref_hash().
Fixes: 725af92a62 ("btrfs: Open-code name_in_log_ref in replay_one_name")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
extent_buffers are global and shared so their pages should not belong to
any particular cgroup (currently whichever cgroups happens to allocate the
extent_buffer).
Btrfs tree operations should not arbitrarily block on cgroup reclaim or
have the shared extent_buffer pages on a cgroup's reclaim lists.
Link: https://lkml.kernel.org/r/2ee99832619a3fdfe80bf4dc9760278662d2d746.1755812945.git.boris@bur.io
Signed-off-by: Boris Burkov <boris@bur.io>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Tested-by: syzbot@syzkaller.appspotmail.com
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qu Wenruo <wqu@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
At this point MIGRATEPAGE_SUCCESS is misnamed for all folio users,
and now that we remove MIGRATEPAGE_UNMAP, it's really the only "success"
return value that the code uses and expects.
Let's just get rid of MIGRATEPAGE_SUCCESS completely and just use "0"
for success.
Link: https://lkml.kernel.org/r/20250811143949.1117439-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com> [mm]
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> [jfs]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Byungchul Park <byungchul@sk.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Eugenio Pé rez <eperezma@redhat.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Lance Yang <lance.yang@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge tag 'for-6.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix delayed inode tracking in xarray, eviction can race with
insertion and leave behind a disconnected inode
- on systems with large page (64K) and small block size (4K) fix
compression read that can return partially filled folio
- slightly relax compression option format for backward compatibility,
allow to specify level for LZO although there's only one
- fix simple quota accounting of compressed extents
- validate minimum device size in 'device add'
- update maintainers' entry
* tag 'for-6.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: don't allow adding block device of less than 1 MB
MAINTAINERS: update btrfs entry
btrfs: fix subvolume deletion lockup caused by inodes xarray race
btrfs: fix corruption reading compressed range when block size is smaller than page size
btrfs: accept and ignore compression level for lzo
btrfs: fix squota compressed stats leak
Commit 15ae0410c37a79 ("btrfs-progs: add error handling for
device_get_partition_size_fd_stat()") in btrfs-progs inadvertently
changed it so that if the BLKGETSIZE64 ioctl on a block device returned
a size of 0, this was no longer seen as an error condition.
Unfortunately this is how disconnected NBD devices behave, meaning that
with btrfs-progs 6.16 it's now possible to add a device you can't
remove:
# btrfs device add /dev/nbd0 /root/temp
# btrfs device remove /dev/nbd0 /root/temp
ERROR: error removing device '/dev/nbd0': Invalid argument
This check should always have been done kernel-side anyway, so add a
check in btrfs_init_new_device() that the new device doesn't have a size
less than BTRFS_DEVICE_RANGE_RESERVED (i.e. 1 MB).
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.17-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix a few races related to inode link count
- fix inode leak on failure to add link to inode
- move transaction aborts closer to where they happen
* tag 'for-6.17-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: avoid load/store tearing races when checking if an inode was logged
btrfs: fix race between setting last_dir_index_offset and inode logging
btrfs: fix race between logging inode and checking if it was logged before
btrfs: simplify error handling logic for btrfs_link()
btrfs: fix inode leak on failure to add link to inode
btrfs: abort transaction on failure to add link to inode
There is a race condition between inode eviction and inode caching that
can cause a live struct btrfs_inode to be missing from the root->inodes
xarray. Specifically, there is a window during evict() between the inode
being unhashed and deleted from the xarray. If btrfs_iget() is called
for the same inode in that window, it will be recreated and inserted
into the xarray, but then eviction will delete the new entry, leaving
nothing in the xarray:
Thread 1 Thread 2
---------------------------------------------------------------
evict()
remove_inode_hash()
btrfs_iget_path()
btrfs_iget_locked()
btrfs_read_locked_inode()
btrfs_add_inode_to_root()
destroy_inode()
btrfs_destroy_inode()
btrfs_del_inode_from_root()
__xa_erase
In turn, this can cause issues for subvolume deletion. Specifically, if
an inode is in this lost state, and all other inodes are evicted, then
btrfs_del_inode_from_root() will call btrfs_add_dead_root() prematurely.
If the lost inode has a delayed_node attached to it, then when
btrfs_clean_one_deleted_snapshot() calls btrfs_kill_all_delayed_nodes(),
it will loop forever because the delayed_nodes xarray will never become
empty (unless memory pressure forces the inode out). We saw this
manifest as soft lockups in production.
Fix it by only deleting the xarray entry if it matches the given inode
(using __xa_cmpxchg()).
Fixes: 310b2f5d5a ("btrfs: use an xarray to track open inodes in a root")
Cc: stable@vger.kernel.org # 6.11+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Co-authored-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
With 64K page size (aarch64 with 64K page size config) and 4K btrfs
block size, the following workload can easily lead to a corrupted read:
mkfs.btrfs -f -s 4k $dev > /dev/null
mount -o compress $dev $mnt
xfs_io -f -c "pwrite -S 0xff 0 64k" $mnt/base > /dev/null
echo "correct result:"
od -Ad -t x1 $mnt/base
xfs_io -f -c "reflink $mnt/base 32k 0 32k" \
-c "reflink $mnt/base 0 32k 32k" \
-c "pwrite -S 0xff 60k 4k" $mnt/new > /dev/null
echo "incorrect result:"
od -Ad -t x1 $mnt/new
umount $mnt
This shows the following result:
correct result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
incorrect result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0032768 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
0061440 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
Notice the zero in the range [32K, 60K), which is incorrect.
[CAUSE]
With extra trace printk, it shows the following events during od:
(some unrelated info removed like CPU and context)
od-3457 btrfs_do_readpage: enter r/i=5/258 folio=0(65536) prev_em_start=0000000000000000
The "r/i" is indicating the root and inode number. In our case the file
"new" is using ino 258 from fs tree (root 5).
Here notice the @prev_em_start pointer is NULL. This means the
btrfs_do_readpage() is called from btrfs_read_folio(), not from
btrfs_readahead().
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=0 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=4096 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=8192 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=12288 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=16384 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=20480 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=24576 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=28672 got em start=0 len=32768
These above 32K blocks will be read from the first half of the
compressed data extent.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=32768 got em start=32768 len=32768
Note here there is no btrfs_submit_compressed_read() call. Which is
incorrect now.
Although both extent maps at 0 and 32K are pointing to the same compressed
data, their offsets are different thus can not be merged into the same
read.
So this means the compressed data read merge check is doing something
wrong.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=36864 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=40960 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=45056 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=49152 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=53248 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=57344 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=61440 skip uptodate
od-3457 btrfs_submit_compressed_read: cb orig_bio: file off=0 len=61440
The function btrfs_submit_compressed_read() is only called at the end of
folio read. The compressed bio will only have an extent map of range [0,
32K), but the original bio passed in is for the whole 64K folio.
This will cause the decompression part to only fill the first 32K,
leaving the rest untouched (aka, filled with zero).
This incorrect compressed read merge leads to the above data corruption.
There were similar problems that happened in the past, commit 808f80b467
("Btrfs: update fix for read corruption of compressed and shared
extents") is doing pretty much the same fix for readahead.
But that's back to 2015, where btrfs still only supports bs (block size)
== ps (page size) cases.
This means btrfs_do_readpage() only needs to handle a folio which
contains exactly one block.
Only btrfs_readahead() can lead to a read covering multiple blocks.
Thus only btrfs_readahead() passes a non-NULL @prev_em_start pointer.
With v5.15 kernel btrfs introduced bs < ps support. This breaks the above
assumption that a folio can only contain one block.
Now btrfs_read_folio() can also read multiple blocks in one go.
But btrfs_read_folio() doesn't pass a @prev_em_start pointer, thus the
existing bio force submission check will never be triggered.
In theory, this can also happen for btrfs with large folios, but since
large folio is still experimental, we don't need to bother it, thus only
bs < ps support is affected for now.
[FIX]
Instead of passing @prev_em_start to do the proper compressed extent
check, introduce one new member, btrfs_bio_ctrl::last_em_start, so that
the existing bio force submission logic will always be triggered.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The compression level is meaningless for lzo, but before commit
3f093ccb95 ("btrfs: harden parsing of compression mount options"),
it was silently ignored if passed.
After that commit, passing a level with lzo fails to mount:
BTRFS error: unrecognized compression value lzo:1
It seems reasonable for users to expect that lzo would permit a numeric
level option, as all the other algos do, even though the kernel's
implementation of LZO currently only supports a single level. Because it
has always worked to pass a level, it seems likely to me that users in
the real world are relying on doing so.
This patch restores the old behavior, giving "lzo:N" the same semantics
as all of the other compression algos.
To be clear, silly variants like "lzo:one", "lzo:the_first_option", or
"lzo:armageddon" also used to work. This isn't meant to suggest that
any possible mis-interpretation of mount options that once worked must
continue to work forever. This is an exceptional case where it makes
sense to preserve compatibility, both because the mis-interpretation is
reasonable, and because nothing tangible is sacrificed.
Finally update btrfs_show_options() to ignore the level of LZO, as it
is only the default level without any extra meaning.
Fixes: 3f093ccb95 ("btrfs: harden parsing of compression mount options")
Reviewed-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The following workload on a squota enabled fs:
btrfs subvol create mnt/subvol
# ensure subvol extents get accounted
sync
btrfs qgroup create 1/1 mnt
btrfs qgroup assign mnt/subvol 1/1 mnt
btrfs qgroup delete mnt/subvol
# make the cleaner thread run
btrfs filesystem sync mnt
sleep 1
btrfs filesystem sync mnt
btrfs qgroup destroy 1/1 mnt
will fail with EBUSY. The reason is that 1/1 does the quick accounting
when we assign subvol to it, gaining its exclusive usage as excl and
excl_cmpr. But then when we delete subvol, the decrement happens via
record_squota_delta() which does not update excl_cmpr, as squotas does
not make any distinction between compressed and normal extents. Thus,
we increment excl_cmpr but never decrement it, and are unable to delete
1/1. The two possible fixes are to make squota always mirror excl and
excl_cmpr or to make the fast accounting separately track the plain and
cmpr numbers. The latter felt cleaner to me so that is what I opted for.
Fixes: 1e0e9d5771 ("btrfs: add helper for recording simple quota deltas")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
At inode_logged() we do a couple lockless checks for ->logged_trans, and
these are generally safe except the second one in case we get a load or
store tearing due to a concurrent call updating ->logged_trans (either at
btrfs_log_inode() or later at inode_logged()).
In the first case it's safe to compare to the current transaction ID since
once ->logged_trans is set the current transaction, we never set it to a
lower value.
In the second case, where we check if it's greater than zero, we are prone
to load/store tearing races, since we can have a concurrent task updating
to the current transaction ID with store tearing for example, instead of
updating with a single 64 bits write, to update with two 32 bits writes or
four 16 bits writes. In that case the reading side at inode_logged() could
see a positive value that does not match the current transaction and then
return a false negative.
Fix this by doing the second check while holding the inode's spinlock, add
some comments about it too. Also add the data_race() annotation to the
first check to avoid any reports from KCSAN (or similar tools) and comment
about it.
Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At inode_logged() if we find that the inode was not logged before we
update its ->last_dir_index_offset to (u64)-1 with the goal that the
next directory log operation will see the (u64)-1 and then figure out
it must check what was the index of the last logged dir index key and
update ->last_dir_index_offset to that key's offset (this is done in
update_last_dir_index_offset()).
This however has a possibility for a time window where a race can happen
and lead to directory logging skipping dir index keys that should be
logged. The race happens like this:
1) Task A calls inode_logged(), sees ->logged_trans as 0 and then checks
that the inode item was logged before, but before it sets the inode's
->last_dir_index_offset to (u64)-1...
2) Task B is at btrfs_log_inode() which calls inode_logged() early, and
that has set ->last_dir_index_offset to (u64)-1;
3) Task B then enters log_directory_changes() which calls
update_last_dir_index_offset(). There it sees ->last_dir_index_offset
is (u64)-1 and that the inode was logged before (ctx->logged_before is
true), and so it searches for the last logged dir index key in the log
tree and it finds that it has an offset (index) value of N, so it sets
->last_dir_index_offset to N, so that we can skip index keys that are
less than or equal to N (later at process_dir_items_leaf());
4) Task A now sets ->last_dir_index_offset to (u64)-1, undoing the update
that task B just did;
5) Task B will now skip every index key when it enters
process_dir_items_leaf(), since ->last_dir_index_offset is (u64)-1.
Fix this by making inode_logged() not touch ->last_dir_index_offset and
initializing it to 0 when an inode is loaded (at btrfs_alloc_inode()) and
then having update_last_dir_index_offset() treat a value of 0 as meaning
we must check the log tree and update with the index of the last logged
index key. This is fine since the minimum possible value for
->last_dir_index_offset is 1 (BTRFS_DIR_START_INDEX - 1 = 2 - 1 = 1).
This also simplifies the management of ->last_dir_index_offset and now
all accesses to it are done under the inode's log_mutex.
Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's a race between checking if an inode was logged before and logging
an inode that can cause us to mark an inode as not logged just after it
was logged by a concurrent task:
1) We have inode X which was not logged before neither in the current
transaction not in past transaction since the inode was loaded into
memory, so it's ->logged_trans value is 0;
2) We are at transaction N;
3) Task A calls inode_logged() against inode X, sees that ->logged_trans
is 0 and there is a log tree and so it proceeds to search in the log
tree for an inode item for inode X. It doesn't see any, but before
it sets ->logged_trans to N - 1...
3) Task B calls btrfs_log_inode() against inode X, logs the inode and
sets ->logged_trans to N;
4) Task A now sets ->logged_trans to N - 1;
5) At this point anyone calling inode_logged() gets 0 (inode not logged)
since ->logged_trans is greater than 0 and less than N, but our inode
was really logged. As a consequence operations like rename, unlink and
link that happen afterwards in the current transaction end up not
updating the log when they should.
Fix this by ensuring inode_logged() only updates ->logged_trans in case
the inode item is not found in the log tree if after tacking the inode's
lock (spinlock struct btrfs_inode::lock) the ->logged_trans value is still
zero, since the inode lock is what protects setting ->logged_trans at
btrfs_log_inode().
Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of incrementing the inode's link count and refcount early before
adding the link, updating the inode and deleting orphan item, do it after
all those steps succeeded right before calling d_instantiate(). This makes
the error handling logic simpler by avoiding the need for the 'drop_inode'
variable to signal if we need to undo the link count increment and the
inode refcount increase under the 'fail' label.
This also reduces the level of indentation by one, making the code easier
to read.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we fail to update the inode or delete the orphan item we leak the inode
since we update its refcount with the ihold() call to account for the
d_instantiate() call which never happens in case we fail those steps. Fix
this by setting 'drop_inode' to true in case we fail those steps.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we fail to update the inode or delete the orphan item, we must abort
the transaction to prevent persisting an inconsistent state. For example
if we fail to update the inode item, we have the inconsistency of having
a persisted inode item with a link count of N but we have N + 1 inode ref
items and N + 1 directory entries pointing to our inode in case the
transaction gets committed.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana