There are several tracepoints for extent buffer locks that are not used
anymore:
* btrfs_tree_read_unlock_blocking
* btrfs_set_lock_blocking_read
* btrfs_set_lock_blocking_write
* btrfs_tree_read_lock_atomic
These stopped being used after we switched extent buffer locks from a
custom implementation to rw semaphores in commit 196d59ab9c
("btrfs: switch extent buffer tree lock to rw_semaphore").
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Most of our tracepoints have the 'btrfs_' prefix in their names but a few
of them are missing, making it inconsistent. So add the prefix to the ones
that are missing it, creating consistency, making it clear for users these
are btrfs tracepoints and eventually avoid name collisions with other
tracepoints defined by other kernel subsystems.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function needs only to return true or false, so there's no need to
return an integer. Currently it returns 0 when a range with the given
bits is set and 1 when not found, which is a bit counter intuitive too.
So change the function to return a bool instead, returning true when a
range is found and false otherwise. Update the function's documentation
to mention the return value too.
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>
Now that set_extent_bit() was renamed to btrfs_set_extent_bit(), there's
no need to have a __set_extent_bit() function, we can just remove the
double underscore prefix, which we try to avoid according to the coding
style conventions.
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>
Rename the remaning exported functions that don't have a 'btrfs_' prefix.
By convention exported functions should have such prefix to make it clear
they are btrfs specific and to avoid collisions with functions from
elsewhere in the kernel.
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>
This is an exported function so it should have a 'btrfs_' prefix by
convention, to make it clear it's btrfs specific and to avoid collisions
with functions from elsewhere in the kernel.
Rename the function to add 'btrfs_' prefix to it.
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel.
So add a 'btrfs_' prefix to their names to make it clear they are from
btrfs.
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel.
So add a 'btrfs_' prefix to their name to make it clear they are from
btrfs.
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>
We've tested that we are dealing with io tree that is associated to an
inode (its owner is IO_TREE_INODE_IO), so there's no need to call
btrfs_extent_io_tree_to_inode() in a separate line and we just assign
tree->inode to the local inode variable when we declare it.
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel.
So add a 'btrfs_' prefix to their name to make it clear they are from
btrfs. Also remove the 'const' suffix from extent_io_tree_to_inode_const()
since there's no non-const variant anymore and makes the naming consistent
with extent_io_tree_to_fs_info() (no 'const' suffix and returns a const
pointer).
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel.
So add a 'btrfs_' prefix to their name to make it clear they are from
btrfs.
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>
This is an exported function so it should have a 'btrfs_' prefix by
convention, to make it clear it's btrfs specific and to avoid collisions
with functions from elsewhere in the kernel.
So rename it to btrfs_set_extent_bit().
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel. One of them has a
double underscore prefix which is also discouraged.
So remove double underscore prefix where applicable and add a 'btrfs_'
prefix to their name to make it clear they are from btrfs.
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel. Their double
underscore prefix is also discouraged.
So remove their double underscore prefix, add a 'btrfs_' prefix to their
name to make it clear they are from btrfs and a '_bits' suffix to avoid
collision with btrfs_lock_extent() and btrfs_try_lock_extent().
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel. So add a prefix to
their name.
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>
These functions are exported so they should have a 'btrfs_' prefix by
convention, to make it clear they are btrfs specific and to avoid
collisions with functions from elsewhere in the kernel. So add a prefix to
their name.
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>
These trace events don't have the 'btrfs_' prefix in their name, unlike
the other trace events from extent-io-tree.c. So add the prefix to make
them consistent and follow coding style conventions too.
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>
These functions aren't used outside extent-io-tree.c, but yet one of them
(extent_io_tree_to_inode()) is unnecessarily exported in the header.
Furthermore their single use is in a pattern like this:
if (is_inode_io_tree(tree))
foo(extent_io_tree_to_inode(tree), ...);
So we're effectively unnecessarily adding more indirection, checking
twice if tree->owner == IO_TREE_INODE_IO before getting the inode and
doing a non-inline function call to get tree->inode.
Simplify this by removing these helper functions and instead doing
thing like this:
if (tree->owner == IO_TREE_INODE_IO)
foo(tree->inode, ...);
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>
Add more unlikely annotations to branches that lead to EUCLEAN, overall
in the tree checker this helps to reorder instructions for the no-error
case.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we use the following pattern to detect if the folio contains
the end of a file:
if (folio->index == end_index)
folio_zero_range();
But that only works if the folio is page sized.
For the following case, it will not work and leave the range beyond EOF
uninitialized:
The page size is 4K, and the fs block size is also 4K.
16K 20K 24K
| | | |
|
EOF at 22K
And we have a large folio sized 8K at file offset 16K.
In that case, the old "folio->index == end_index" will not work, thus
the range [22K, 24K) will not be zeroed out.
Fix the following call sites which use the above pattern:
- add_ra_bio_pages()
- extent_writepage()
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>
Inside functions unlock_delalloc_folio() and lock_delalloc_folios(), we
have the following early exits:
if (index == locked_folio->index && end_index == index)
return;
This allows us to exit early if the range is inside the same locked
folio.
However the current check relies on page sized folios, if we have a large
folio that contains @index but not at @index, then the early exit will
no longer trigger.
Furthermore without the above early check, the existing code can handle it
well, as both __process_folios_contig() and lock_delalloc_folios() will
skip any folio page lock/unlock if it's on the locked folio.
Here we remove the early exits and let the existing code handle the
same index case, to make the code a little simpler.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of open coding btrfs_root_id() to get the ID of a root, use the
helper in the trace points, which also makes the code less verbose.
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>
The function itself is already taking large folios into consideration,
just remove the ASSERT(!folio_test_large()) line.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The subpage handling code has two locations not supporting large folios:
- btrfs_attach_subpage()
Which is doing a metadata specific ASSERT() check.
But for the future large data folios support, that check is too
generic. Since it's metadata specific, only check the ASSERT() for
metadata.
- btrfs_subpage_assert()
Just remove the "ASSERT(folio_order(folio) == 0)" check.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function is doing an ASSERT() checking the folio order, but all
later functions are handling large folios properly, thus we can safely
remove that ASSERT().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The only blockage is the ASSERT() rejecting large folios, just remove
it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function btrfs_page_mkwrite() has an explicit ASSERT() checking the
folio order.
To make it support large data folios, we need to:
- Remove the ASSERT(folio_order(folio) == 0)
- Use folio_contains() to check if the folio covers the last page
Otherwise the code is already supporting large folios well.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently put_file_data() can only accept a page sized folio. However
the function itself is not that complex, it's just copying data from
filemap folio into the send buffer.
Make it support large data folios:
- Change the loop to use file offset instead of page index
- Calculate @pg_offset and @cur_len after getting the folio
- Remove the "WARN_ON(folio_order(folio));" line
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The again label is here to retry to get the folio for the current index.
When triggering that label, there is no advance of the iterator.
So it can be replaced by a simple "continue" and remove the again label.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The most trivial pattern for the auto freeing when the variable is
declared with the macro and the final btrfs_free_path() is removed.
There are almost none goto -> return conversions and there's no other
function cleanup.
Reviewed-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's pointless to check if the current record's start offset is greater
than the end offset, as before we just tested if it was greater than the
start offset - and if it's not it means it's less than or equal to the
start offset, so it can not be greater than the end offset, as our start
offset is always smaller than the end offset.
So remove that check and also add an assertion to verify the start offset
is smaller then the end offset.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The overflow detection for the start offset of the next record is not
really necessary, we can just stop iterating if the current record ends at
or after out end offset. This removes the need to test if the current
record end offset is (u64)-1 and to check if adding 1 to the current
end offset results in 0.
By testing only if the current record ends at or after the end offset, we
also don't need anymore to test the new start offset at the head of the
while loop.
This makes both the source code and assembly code simpler, more efficient
and shorter (reducing the object text size).
Also remove the pointless initialization to NULL of the state variable, as
we don't use it before the first assignment to it. This may help avoid
some warnings with clang tools such as the one reported/fixed by commit
966de47ff0 ("btrfs: remove redundant initialization of variables in
log_new_ancestors").
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The tree_search() function always returns an entry that either contains
the search offset or the first entry in the tree that starts after the
offset. So checking at find_first_extent_bit_state() if the returned
entry ends at or after the search offset is pointless. Remove the check.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are several things wrong with the documentation:
1) At the top it's only mentioned that we search for an entry containing
the given offset, but when such entry does not exists we search for
the first entry that starts and ends after that offset;
2) It mentions that @node_ret and @parent_ret aren't changed if the
returned entry contains the given offset - that is true only if the
returned entry starts exactly at @offset, otherwise those arguments
are changed;
3) It mentions that if no entry containing offset is found then we return
the first entry ending before the offset - that is not true, we return
the first entry that starts and ends after that offset;
4) It also mentions that NULL is never returned. This is false as in case
there's no entry containing offset or any entry that starts and ends
after offset, NULL is returned.
So fix the documentation.
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 keeping track of the minimum start offset of the next record
and detecting overflow every time we update that offset to be the sum of
current record's end offset plus one, we can simply exit when the current
record ends at or beyond our end offset and forget about updating the
start offset on every iteration and testing for it at the top of the loop.
This makes both the source code and assembly code simpler, more efficient
and shorter (reducing the object text size).
Also remove the pointless initialization to NULL of the state variable, as
we don't use it before the first assignment to it. This may help avoid
some warnings with clang tools such as the one reported/fixed by commit
966de47ff0 ("btrfs: remove redundant initialization of variables in
log_new_ancestors").
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>
Several places are using clear_extent_bit() and passing a NULL value for
the 'cached' argument, which is pointless as they can use instead
clear_extent_bits().
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 using __clear_extent_bit() we can use clear_extent_bits() since
we pass a NULL value for the cached and changeset arguments.
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 using __clear_extent_bit() we can use clear_extent_bit() since
we pass a NULL value for the changeset argument.
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>
[BUG WITH EXPERIMENTAL LARGE FOLIOS]
When testing the experimental large data folio support with compression,
there are several ASSERT()s triggered from btrfs_decompress_buf2page()
when running fsstress with compress=zstd mount option:
- ASSERT(copy_len) from btrfs_decompress_buf2page()
- VM_BUG_ON(offset + len > PAGE_SIZE) from memcpy_to_page()
[CAUSE]
Inside btrfs_decompress_buf2page(), we need to grab the file offset from
the current bvec.bv_page, to check if we even need to copy data into the
bio.
And since we're using single page bvec, and no large folio, every page
inside the folio should have its index properly setup.
But when large folios are involved, only the first page (aka, the head
page) of a large folio has its index properly initialized.
The other pages inside the large folio will not have their indexes
properly initialized.
Thus the page_offset() call inside btrfs_decompress_buf2page() will
result garbage, and completely screw up the @copy_len calculation.
[FIX]
Instead of using page->index directly, go with page_pgoff(), which can
handle non-head pages correctly.
So introduce a helper, file_offset_from_bvec(), to get the file offset
from a single page bio_vec, so the copy_len calculation can be done
correctly.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Simplify conditionally reading an rb_entry(), there's the
rb_entry_safe() helper that checks the node pointer for NULL so we don't
have to write it explicitly.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Allow get_range_bits() to take an extent state pointer to pointer argument
so that we can cache the first extent state record in the target range, so
that a caller can use it for subsequent operations without doing a full
tree search. Currently the only user is try_release_extent_state(), which
then does a call to __clear_extent_bit() which can use such a cached state
record.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When the release_folio callback (from struct address_space_operations) is
invoked we don't allow the folio to be released if its range is currently
locked in the inode's io_tree, as it may indicate the folio may be needed
by the task that locked the range.
However if the range is locked because an ordered extent is finishing,
then we can safely allow the folio to be released because ordered extent
completion doesn't need to use the folio at all.
When we are under memory pressure, the kernel starts writeback of dirty
pages (folios) with the goal of releasing the pages from the page cache
after writeback completes, however this often is not possible on btrfs
because:
* Once the writeback completes we queue the ordered extent completion;
* Once the ordered extent completion starts, we lock the range in the
inode's io_tree (at btrfs_finish_one_ordered());
* If the release_folio callback is called while the folio's range is
locked in the inode's io_tree, we don't allow the folio to be
released, so the kernel has to try to release memory elsewhere,
which may result in triggering more writeback or releasing other
pages from the page cache which may be more useful to have around
for applications.
In contrast, when the release_folio callback is invoked after writeback
finishes and before ordered extent completion starts or locks the range,
we allow the folio to be released, as well as when the release_folio
callback is invoked after ordered extent completion unlocks the range.
Improve on this by detecting if the range is locked for ordered extent
completion and if it is, allow the folio to be released. This detection
is achieved by adding a new extent flag in the io_tree that is set when
the range is locked during ordered extent completion.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Drop reference to pages from the comment since the function is fully folio
aware and works regardless of how many pages are in the folio. Also while
at it, capitalize the first word and make it more explicit that
release_folio is a callback from struct address_space_operations.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function btrfs_punch_hole_lock_range() needs to make sure there is
no other folio in the range, thus it goes with filemap_range_has_page(),
which works pretty fine.
But if we have large folios, under the following case
filemap_range_has_page() will always return true, forcing
btrfs_punch_hole_lock_range() to do a very time consuming busy loop:
start end
| |
|//|//|//|//| | | | | | | | |//|//|
\ / \ /
Folio A Folio B
In the above case, folio A and B contain our start/end indexes, and there
are no other folios in the range. Thus we do not need to retry inside
btrfs_punch_hole_lock_range().
To prepare for large data folios, introduce a helper,
check_range_has_page(), which will:
- Shrink the search range towards page boundaries
If the rounded down end (exclusive, otherwise it can underflow when @end
is inside the folio at file offset 0) is no larger than the rounded up
start, it means the range contains no other pages other than the ones
covering @start and @end.
Can return false directly in that case.
- Grab all the folios inside the range
- Skip any large folios that cover the start and end indexes
- If any other folios are found return true
- Otherwise return false
This new helper is going to handle both large folios and regular ones.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
