We have a few places where we skip doing csums if we mounted with one of
the rescue options that ignores bad csum roots. In the future when
there are multiple csum roots it'll be costly to check and see if there
are any missing csum roots, so simply add a flag to indicate the fs
should skip loading csums in case of errors.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We used to need the root for btrfs_reserve_metadata_bytes to check the
orphan cleanup state, but we no longer need that, we simply need the
fs_info. Change btrfs_reserve_metadata_bytes() to use the fs_info, and
change both btrfs_block_rsv_refill() and btrfs_block_rsv_add() to do the
same as they simply call btrfs_reserve_metadata_bytes() and then
manipulate the block_rsv that is being used.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we don't care about the stage of the orphan_cleanup_state,
simply replace it with a bit on ->state to make sure we don't call the
orphan cleanup every time we wander into this root.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I forgot to convert this over when I introduced the global reserve
stealing code to the space flushing code. Evict was simply trying to
make its reservation and then if it failed it would steal from the
global rsv, which is racey because it's outside of the normal ticketing
code.
Fix this by setting ticket->steal if we are BTRFS_RESERVE_FLUSH_EVICT,
and then make the priority flushing path do the steal for us.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of getting the btrfs_item for this, simply pass in the slot of
the item and then use the btrfs_item_size_nr() helper inside of
btrfs_file_extent_inline_item_len().
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing a direct IO write against a file range that either has
preallocated extents in that range or has regular extents and the file
has the NOCOW attribute set, the write fails with -ENOSPC when all of
the following conditions are met:
1) There are no data blocks groups with enough free space matching
the size of the write;
2) There's not enough unallocated space for allocating a new data block
group;
3) The extents in the target file range are not shared, neither through
snapshots nor through reflinks.
This is wrong because a NOCOW write can be done in such case, and in fact
it's possible to do it using a buffered IO write, since when failing to
allocate data space, the buffered IO path checks if a NOCOW write is
possible.
The failure in direct IO write path comes from the fact that early on,
at btrfs_dio_iomap_begin(), we try to allocate data space for the write
and if it that fails we return the error and stop - we never check if we
can do NOCOW. But later, at btrfs_get_blocks_direct_write(), we check
if we can do a NOCOW write into the range, or a subset of the range, and
then release the previously reserved data space.
Fix this by doing the data reservation only if needed, when we must COW,
at btrfs_get_blocks_direct_write() instead of doing it at
btrfs_dio_iomap_begin(). This also simplifies a bit the logic and removes
the inneficiency of doing unnecessary data reservations.
The following example test script reproduces the problem:
$ cat dio-nocow-enospc.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
# Use a small fixed size (1G) filesystem so that it's quick to fill
# it up.
# Make sure the mixed block groups feature is not enabled because we
# later want to not have more space available for allocating data
# extents but still have enough metadata space free for the file writes.
mkfs.btrfs -f -b $((1024 * 1024 * 1024)) -O ^mixed-bg $DEV
mount $DEV $MNT
# Create our test file with the NOCOW attribute set.
touch $MNT/foobar
chattr +C $MNT/foobar
# Now fill in all unallocated space with data for our test file.
# This will allocate a data block group that will be full and leave
# no (or a very small amount of) unallocated space in the device, so
# that it will not be possible to allocate a new block group later.
echo
echo "Creating test file with initial data..."
xfs_io -c "pwrite -S 0xab -b 1M 0 900M" $MNT/foobar
# Now try a direct IO write against file range [0, 10M[.
# This should succeed since this is a NOCOW file and an extent for the
# range was previously allocated.
echo
echo "Trying direct IO write over allocated space..."
xfs_io -d -c "pwrite -S 0xcd -b 10M 0 10M" $MNT/foobar
umount $MNT
When running the test:
$ ./dio-nocow-enospc.sh
(...)
Creating test file with initial data...
wrote 943718400/943718400 bytes at offset 0
900 MiB, 900 ops; 0:00:01.43 (625.526 MiB/sec and 625.5265 ops/sec)
Trying direct IO write over allocated space...
pwrite: No space left on device
A test case for fstests will follow, testing both this direct IO write
scenario as well as the buffered IO write scenario to make it less likely
to get future regressions on the buffered IO case.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"The updates this time are more under the hood and enhancing existing
features (subpage with compression and zoned namespaces).
Performance related:
- misc small inode logging improvements (+3% throughput, -11% latency
on sample dbench workload)
- more efficient directory logging: bulk item insertion, less tree
searches and locking
- speed up bulk insertion of items into a b-tree, which is used when
logging directories, when running delayed items for directories
(fsync and transaction commits) and when running the slow path
(full sync) of an fsync (bulk creation run time -4%, deletion -12%)
Core:
- continued subpage support
- make defragmentation work
- make compression write work
- zoned mode
- support ZNS (zoned namespaces), zone capacity is number of
usable blocks in each zone
- add dedicated block group (zoned) for relocation, to prevent
out of order writes in some cases
- greedy block group reclaim, pick the ones with least usable
space first
- preparatory work for send protocol updates
- error handling improvements
- cleanups and refactoring
Fixes:
- lockdep warnings
- in show_devname callback, on seeding device
- device delete on loop device due to conversions to workqueues
- fix deadlock between chunk allocation and chunk btree modifications
- fix tracking of missing device count and status"
* tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (140 commits)
btrfs: remove root argument from check_item_in_log()
btrfs: remove root argument from add_link()
btrfs: remove root argument from btrfs_unlink_inode()
btrfs: remove root argument from drop_one_dir_item()
btrfs: clear MISSING device status bit in btrfs_close_one_device
btrfs: call btrfs_check_rw_degradable only if there is a missing device
btrfs: send: prepare for v2 protocol
btrfs: fix comment about sector sizes supported in 64K systems
btrfs: update device path inode time instead of bd_inode
fs: export an inode_update_time helper
btrfs: fix deadlock when defragging transparent huge pages
btrfs: sysfs: convert scnprintf and snprintf to sysfs_emit
btrfs: make btrfs_super_block size match BTRFS_SUPER_INFO_SIZE
btrfs: update comments for chunk allocation -ENOSPC cases
btrfs: fix deadlock between chunk allocation and chunk btree modifications
btrfs: zoned: use greedy gc for auto reclaim
btrfs: check-integrity: stop storing the block device name in btrfsic_dev_state
btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls
btrfs: add a btrfs_get_dev_args_from_path helper
btrfs: handle device lookup with btrfs_dev_lookup_args
...
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Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- mq-deadline accounting improvements (Bart)
- blk-wbt timer fix (Andrea)
- Untangle the block layer includes (Christoph)
- Rework the poll support to be bio based, which will enable adding
support for polling for bio based drivers (Christoph)
- Block layer core support for multi-actuator drives (Damien)
- blk-crypto improvements (Eric)
- Batched tag allocation support (me)
- Request completion batching support (me)
- Plugging improvements (me)
- Shared tag set improvements (John)
- Concurrent queue quiesce support (Ming)
- Cache bdev in ->private_data for block devices (Pavel)
- bdev dio improvements (Pavel)
- Block device invalidation and block size improvements (Xie)
- Various cleanups, fixes, and improvements (Christoph, Jackie,
Masahira, Tejun, Yu, Pavel, Zheng, me)
* tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits)
blk-mq-debugfs: Show active requests per queue for shared tags
block: improve readability of blk_mq_end_request_batch()
virtio-blk: Use blk_validate_block_size() to validate block size
loop: Use blk_validate_block_size() to validate block size
nbd: Use blk_validate_block_size() to validate block size
block: Add a helper to validate the block size
block: re-flow blk_mq_rq_ctx_init()
block: prefetch request to be initialized
block: pass in blk_mq_tags to blk_mq_rq_ctx_init()
block: add rq_flags to struct blk_mq_alloc_data
block: add async version of bio_set_polled
block: kill DIO_MULTI_BIO
block: kill unused polling bits in __blkdev_direct_IO()
block: avoid extra iter advance with async iocb
block: Add independent access ranges support
blk-mq: don't issue request directly in case that current is to be blocked
sbitmap: silence data race warning
blk-cgroup: synchronize blkg creation against policy deactivation
block: refactor bio_iov_bvec_set()
block: add single bio async direct IO helper
...
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Merge tag 'for-5.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Last minute fixes for crash on 32bit architectures when compression is
in use. It's a regression introduced in 5.15-rc and I'd really like
not let this into the final release, fixes via stable trees would add
unnecessary delay.
The problem is on 32bit architectures with highmem enabled, the pages
for compression may need to be kmapped, while the patches removed that
as we don't use GFP_HIGHMEM allocations anymore. The pages that don't
come from local allocation still may be from highmem. Despite being on
32bit there's enough such ARM machines in use so it's not a marginal
issue.
I did full reverts of the patches one by one instead of a huge one.
There's one exception for the "lzo" revert as there was an
intermediate patch touching the same code to make it compatible with
subpage. I can't revert that one too, so the revert in lzo.c is
manual. Qu Wenruo has worked on that with me and verified the changes"
* tag 'for-5.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Revert "btrfs: compression: drop kmap/kunmap from lzo"
Revert "btrfs: compression: drop kmap/kunmap from zlib"
Revert "btrfs: compression: drop kmap/kunmap from zstd"
Revert "btrfs: compression: drop kmap/kunmap from generic helpers"
The root argument passed to btrfs_unlink_inode() and its callee,
__btrfs_unlink_inode(), always matches the root of the given directory and
the given inode. So remove the argument and make __btrfs_unlink_inode()
use the root of the directory.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The member btrfs_bio::logical is only initialized by two call sites:
- btrfs_repair_one_sector()
No corresponding site to utilize it.
- btrfs_submit_direct()
The corresponding site to utilize it is btrfs_check_read_dio_bio().
However for btrfs_check_read_dio_bio(), we can grab the file_offset from
btrfs_dio_private::file_offset directly.
Thus it turns out we don't really need that btrfs_bio::logical member at
all.
For btrfs_bio, the logical bytenr can be fetched from its
bio->bi_iter.bi_sector directly.
So let's just remove the member to save 8 bytes for structure btrfs_bio.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The naming of "logical_offset" can be confused with logical bytenr of
the dio range.
In fact it's file offset, and the naming "file_offset" is already widely
used in all other sites.
Just do the rename to avoid confusion.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of checking whether qgroup processing for a dealyed ref has to
happen in the core of delayed ref, simply pull the check at init time of
respective delayed ref structures. This eliminates the final use of
real_root in delayed-ref core paving the way to making this member
optional.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In order to make 'real_root' used only in ref-verify it's required to
have the necessary context to perform the same checks that this member
is used for. So add 'mod_root' which will contain the root on behalf of
which a delayed ref was created and a 'skip_group' parameter which
will contain callsite-specific override of skip_qgroup.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a few flags that are inconsistently used to describe the fs in
different states of failure. As of 5963ffcaf3 ("btrfs: always abort
the transaction if we abort a trans handle") we will always set
BTRFS_FS_STATE_ERROR if we abort, so we don't have to check both ABORTED
and ERROR to see if things have gone wrong. Add a helper to check
BTRFS_FS_STATE_ERROR and then convert all checkers of FS_STATE_ERROR to
use the helper.
The TRANS_ABORTED bit check was added in af72273381 ("Btrfs: clean up
resources during umount after trans is aborted") but is not actually
specific.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we will abort the transaction if we get a random error (like
-EIO) while trying to remove the directory entries from the root log
during rename.
However since these are simply log tree related errors, we can mark the
trans as needing a full commit. Then if the error was truly
catastrophic we'll hit it during the normal commit and abort as
appropriate.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For compressed write, we use a mechanism called async COW, which unlike
regular run_delalloc_cow() or cow_file_range() will also unlock the
first page.
This mechanism allows us to continue handling next ranges, without
waiting for the time consuming compression.
But this has a problem for subpage case, as we could have the following
delalloc range for a page:
0 32K 64K
| |///////| |///////|
\- A \- B
In the above case, if we pass both ranges to cow_file_range_async(),
both range A and range B will try to unlock the full page [0, 64K).
And which one finishes later than the other one will try to do other
page operations like end_page_writeback() on a unlocked page, triggering
VM layer BUG_ON().
To make subpage compression work at least partially, here we add another
restriction for it, only allow compression if the delalloc range is
fully page aligned.
By that, async extent is always ensured to unlock the first page
exclusively, just like it used to be for regular sectorsize.
In theory, we only need to make sure the delalloc range fully covers its
first page, but the tail page will be locked anyway, blocking later
writeback until the compression finishes.
Thus here we choose to make sure the range is fully page aligned before
doing the compression.
In the future, we could optimize the situation by properly increasing
subpage::writers number for the locked page, but that also means we need
to change how we run delalloc range of page.
(Instead of running each delalloc range we hit, we need to find and lock
all delalloc ranges covering the page, then run each of them).
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
With experimental subpage compression enabled, a simple fsstress can
lead to self deadlock on page 720896:
mkfs.btrfs -f -s 4k $dev > /dev/null
mount $dev -o compress $mnt
$fsstress -p 1 -n 100 -w -d $mnt -v -s 1625511156
[CAUSE]
If we have a file layout looks like below:
0 32K 64K 96K 128K
|//| |///////////////|
4K
Then we run delalloc range for the inode, it will:
- Call find_lock_delalloc_range() with @delalloc_start = 0
Then we got a delalloc range [0, 4K).
This range will be COWed.
- Call find_lock_delalloc_range() again with @delalloc_start = 4K
Since find_lock_delalloc_range() never cares whether the range
is still inside page range [0, 64K), it will return range [64K, 128K).
This range meets the condition for subpage compression, will go
through async COW path.
And async COW path will return @page_started.
But that @page_started is now for range [64K, 128K), not for range
[0, 64K).
- writepage_dellloc() returned 1 for page [0, 64K)
Thus page [0, 64K) will not be unlocked, nor its page dirty status
will be cleared.
Next time when we try to lock page [0, 64K) we will deadlock, as there
is no one to release page [0, 64K).
This problem will never happen for regular page size as one page only
contains one sector. After the first find_lock_delalloc_range() call,
the @delalloc_end will go beyond @page_end no matter if we found a
delalloc range or not
Thus this bug only happens for subpage, as now we need multiple runs to
exhaust the delalloc range of a page.
[FIX]
Fix the problem by ensuring the delalloc range we ran at least started
inside @locked_page.
So that we will never get incorrect @page_started.
And to prevent such problem from happening again:
- Make find_lock_delalloc_range() return false if the found range is
beyond @end value passed in.
Since @end will be utilized now, add an ASSERT() to ensure we pass
correct @end into find_lock_delalloc_range().
This also means, for selftests we needs to populate @end before calling
find_lock_delalloc_range().
- New ASSERT() in find_lock_delalloc_range()
Now we will make sure the @start/@end passed in at least covers part
of the page.
- New ASSERT() in run_delalloc_range()
To make sure the range at least starts inside @locked page.
- Use @delalloc_start as proper cursor, while @delalloc_end is always
reset to @page_end.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a new helper, submit_uncompressed_range(), for async cow cases
where we fallback to COW.
There are some new updates introduced to the helper:
- Proper locked_page detection
It's possible that the async_extent range doesn't cover the locked
page. In that case we shouldn't unlock the locked page.
In the new helper, we will ensure that we only unlock the locked page
when:
* The locked page covers part of the async_extent range
* The locked page is not unlocked by cow_file_range() nor
extent_write_locked_range()
This also means extra comments are added focusing on the page locking.
- Add extra comment on some rare parameter used.
We use @unlock_page = 0 for cow_file_range(), where only two call
sites doing the same thing, including the new helper.
It's definitely worth some comments.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In function compress_file_range(), when the compression is finished, the
function just rounds up @total_in to PAGE_SIZE. This is fine for
regular sectorsize == PAGE_SIZE case, but not for subpage.
Just change the ALIGN(, PAGE_SIZE) to round_up(, sectorsize) so that
both regular sectorsize and subpage sectorsize will be happy.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are several cleanups for extent_write_locked_range(), most of them
are pure cleanups, but with some preparation for future subpage support.
- Add a proper comment for which call sites are suitable
Unlike regular synchronized extent write back, if async COW or zoned
COW happens, we have all pages in the range still locked.
Thus for those (only) two call sites, we need this function to submit
page content into bios and submit them.
- Remove @mode parameter
All the existing two call sites pass WB_SYNC_ALL. No need for @mode
parameter.
- Better error handling
Currently if we hit an error during the page iteration loop, we
overwrite @ret, causing only the last error can be recorded.
Here we add @found_error and @first_error variable to record if we hit
any error, and the first error we hit.
So the first error won't get lost.
- Don't reuse @start as the cursor
We reuse the parameter @start as the cursor to iterate the range, not
a big problem, but since we're here, introduce a proper @cur as the
cursor.
- Remove impossible branch
Since all pages are still locked after the ordered extent is inserted,
there is no way that pages can get its dirty bit cleared.
Remove the branch where page is not dirty and replace it with an
ASSERT().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a big chunk of code inside a while() loop, with tons of strange
jumps for error handling. It's definitely not to the code standard of
today. Move the code into a new function, submit_one_async_extent().
Since we're here, also do the following changes:
- Comment style change
To follow the current scheme
- Don't fallback to non-compressed write then hitting ENOSPC
If we hit ENOSPC for compressed write, how could we reserve more space
for non-compressed write?
Thus we go error path directly.
This removes the retry: label.
- Add more comment for super long parameter list
Explain which parameter is for, so we don't need to check the
prototype.
- Move the error handling to submit_one_async_extent()
Thus no strange code like:
out_free:
...
goto again;
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As the last caller in compression.c has been removed, we don't need that
function anymore.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Although in btrfs we have very limited usage of PageChecked flag, it's
still some page flag not yet subpage compatible.
Fix it by introducing btrfs_subpage::checked_offset to do the convert.
For most call sites, especially for free-space cache, COW fixup and
btrfs_invalidatepage(), they all work in full page mode anyway.
For other call sites, they work as subpage compatible mode.
Some call sites need extra modification:
- btrfs_drop_pages()
Needs extra parameter to get the real range we need to clear checked
flag.
Also since btrfs_drop_pages() will accept pages beyond the dirtied
range, update btrfs_subpage_clamp_range() to handle such case
by setting @len to 0 if the page is beyond target range.
- btrfs_invalidatepage()
We need to call subpage helper before calling __btrfs_releasepage(),
or it will trigger ASSERT() as page->private will be cleared.
- btrfs_verify_data_csum()
In theory we don't need the io_bio->csum check anymore, but it's
won't hurt. Just change the comment.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since async_extent holds the compressed page, it would trigger the new
ASSERT() in btrfs_mark_ordered_io_finished() which checks that the range
is inside the page.
Now btrfs_writepage_endio_finish_ordered() can accept @page == NULL,
just pass NULL to btrfs_writepage_endio_finish_ordered().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For structure async_chunk, we use a very strange member layout to grab
structure async_cow who owns this async_chunk.
At initialization, it goes like this:
async_chunk[i].pending = &ctx->num_chunks;
Then at async_cow_free() we do a super weird freeing:
/*
* Since the pointer to 'pending' is at the beginning of the array of
* async_chunk's, freeing it ensures the whole array has been freed.
*/
if (atomic_dec_and_test(async_chunk->pending))
kvfree(async_chunk->pending);
This is absolutely an abuse of kvfree().
Replace async_chunk::pending with async_chunk::async_cow, so that we can
grab the async_cow structure directly, without this strange dancing.
And with this change, there is no requirement for any specific member
location.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When inserting a batch of items into a btree, we end up looping over the
data sizes array 3 times:
1) Once in the caller of btrfs_insert_empty_items(), when it populates the
array with the data sizes for each item;
2) Once at btrfs_insert_empty_items() to sum the elements of the data
sizes array and compute the total data size;
3) And then once again at setup_items_for_insert(), where we do exactly
the same as what we do at btrfs_insert_empty_items(), to compute the
total data size.
That is not bad for small arrays, but when the arrays have hundreds of
elements, the time spent on looping is not negligible. For example when
doing batch inserts of delayed items for dir index items or when logging
a directory, it's common to have 200 to 260 dir index items in a single
batch when using a leaf size of 16K and using file names between 8 and 12
characters. For a 64K leaf size, multiply that by 4. Taking into account
that during directory logging or when flushing delayed dir index items we
can have many of those large batches, the time spent on the looping adds
up quickly.
It's also more important to avoid it at setup_items_for_insert(), since
we are holding a write lock on a leaf and, in some cases, on upper nodes
of the btree, which causes us to block other tasks that want to access
the leaf and nodes for longer than necessary.
So change the code so that setup_items_for_insert() and
btrfs_insert_empty_items() no longer compute the total data size, and
instead rely on the caller to supply it. This makes us loop over the
array only once, where we can both populate the data size array and
compute the total data size, taking advantage of spatial and temporal
locality. To make this more manageable, use a structure to contain
all the relevant details for a batch of items (keys array, data sizes
array, total data size, number of items), and use it as an argument
for btrfs_insert_empty_items() and setup_items_for_insert().
This patch is part of a small patchset that is comprised of the following
patches:
btrfs: loop only once over data sizes array when inserting an item batch
btrfs: unexport setup_items_for_insert()
btrfs: use single bulk copy operations when logging directories
This is patch 1/3 and performance results, and the specific tests, are
included in the changelog of patch 3/3.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Previously we had "struct btrfs_bio", which records IO context for
mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra
btrfs specific info for logical bytenr bio.
With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename
"btrfs_io_bio" to "btrfs_bio" which is a more suitable name now.
The struct btrfs_bio changes meaning by this commit. There was a
suggested name like btrfs_logical_bio but it's a bit long and we'd
prefer to use a shorter name.
This could be a concern for backports to older kernels where the
different meaning could possibly cause confusion or bugs. Comparing the
new and old structures, there's no overlap among the struct members so a
build would break in case of incorrect backport.
We haven't had many backports to bio code anyway so this is more of a
theoretical cause of bugs and a matter of precaution but we'll need to
keep the semantic change in mind.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After the first time we log a directory in the current transaction, for
each directory item in a changed leaf of the subvolume tree, we have to
check if we previously logged the item, in order to overwrite it in case
its data changed or skip it in case its data hasn't changed.
Checking if we have logged each item before not only wastes times, but it
also adds lock contention on the log tree. So in order to minimize the
number of times we do such checks, keep track of the offset of the last
key we logged for a directory and, on the next time we log the directory,
skip the checks for any new keys that have an offset greater than the
offset we have previously saved. This is specially effective for index
keys, because the offset for these keys comes from a monotonically
increasing counter.
This patch is part of a patchset comprised of the following 5 patches:
btrfs: remove root argument from btrfs_log_inode() and its callees
btrfs: remove redundant log root assignment from log_dir_items()
btrfs: factor out the copying loop of dir items from log_dir_items()
btrfs: insert items in batches when logging a directory when possible
btrfs: keep track of the last logged keys when logging a directory
This is patch 5/5.
The following test was used on a non-debug kernel to measure the impact
it has on a directory fsync:
$ cat test-dir-fsync.sh
#!/bin/bash
DEV=/dev/nvme0n1
MNT=/mnt/nvme0n1
NUM_NEW_FILES=100000
NUM_FILE_DELETES=1000
mkfs.btrfs -f $DEV
mount -o ssd $DEV $MNT
mkdir $MNT/testdir
for ((i = 1; i <= $NUM_NEW_FILES; i++)); do
echo -n > $MNT/testdir/file_$i
done
# fsync the directory, this will log the new dir items and the inodes
# they point to, because these are new inodes.
start=$(date +%s%N)
xfs_io -c "fsync" $MNT/testdir
end=$(date +%s%N)
dur=$(( (end - start) / 1000000 ))
echo "dir fsync took $dur ms after adding $NUM_NEW_FILES files"
# sync to force transaction commit and wipeout the log.
sync
del_inc=$(( $NUM_NEW_FILES / $NUM_FILE_DELETES ))
for ((i = 1; i <= $NUM_NEW_FILES; i += $del_inc)); do
rm -f $MNT/testdir/file_$i
done
# fsync the directory, this will only log dir items, there are no
# dentries pointing to new inodes.
start=$(date +%s%N)
xfs_io -c "fsync" $MNT/testdir
end=$(date +%s%N)
dur=$(( (end - start) / 1000000 ))
echo "dir fsync took $dur ms after deleting $NUM_FILE_DELETES files"
umount $MNT
Test results with NUM_NEW_FILES set to 100 000 and 1 000 000:
**** before patchset, 100 000 files, 1000 deletes ****
dir fsync took 848 ms after adding 100000 files
dir fsync took 175 ms after deleting 1000 files
**** after patchset, 100 000 files, 1000 deletes ****
dir fsync took 758 ms after adding 100000 files (-11.2%)
dir fsync took 63 ms after deleting 1000 files (-94.1%)
**** before patchset, 1 000 000 files, 1000 deletes ****
dir fsync took 9945 ms after adding 1000000 files
dir fsync took 473 ms after deleting 1000 files
**** after patchset, 1 000 000 files, 1000 deletes ****
dir fsync took 8677 ms after adding 1000000 files (-13.6%)
dir fsync took 146 ms after deleting 1000 files (-105.6%)
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Prepare for allowing preallocation for relocation inodes.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are several places in our codebase where we check if a root is the
root of the data reloc tree and subsequent patches will introduce more.
Factor out the check into a small helper function instead of open coding
it multiple times.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In preparation to fix a bug in btrfs_show_devname().
Convert fs_devices::latest_bdev type from struct block_device to struct
btrfs_device and, rename the member to fs_devices::latest_dev.
So that btrfs_show_devname() can use fs_devices::latest_dev::name.
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have written to the zone capacity, the device automatically
deactivates the zone. Sync up block group side (the active BG list and
zone_is_active flag) with it.
We need to do it both on data BGs and metadata BGs. On data side, we add a
hook to btrfs_finish_ordered_io(). On metadata side, we use
end_extent_buffer_writeback().
To reduce excess lookup of a block group, we mark the last extent buffer in
a block group with EXTENT_BUFFER_ZONE_FINISH flag. This cannot be done for
data (ordered_extent), because the address may change due to
REQ_OP_ZONE_APPEND.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.
Polling for the bio itself leads to a few advantages:
- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-cgroup.h pulls in blkdev.h and thus pretty much all the block
headers. Break this dependency chain by turning wbc_blkcg_css into a
macro and dropping the blk-cgroup.h include.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
- Simplify the bio_end_page usage in the buffered IO code.
- Support reading inline data at nonzero offsets for erofs.
- Fix some typos and bad grammar.
- Convert kmap_atomic usage in the inline data read path.
- Add some extra inline data input checking.
- Fix a memory corruption bug stemming from iomap_swapfile_activate
trying to activate more pages than mm was expecting.
- Pass errnos through the page writeback code so that writeback errors
are reported correctly instead of being munged to EIO.
- Replace iomap_apply with a open-coded iterator loops to reduce the
number of indirect calls by a third to a half.
- Refactor the fsdax code to use iomap iterators instead of the
open-coded iomap_apply code that it had before.
- Format file range iomap tracepoint data in hexadecimal and
standardize the names used in the pretty-print string.
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Merge tag 'iomap-5.15-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap updates from Darrick Wong:
"The most notable externally visible change for this cycle is the
addition of support for reads to inline tail fragments of files, which
was requested by the erofs developers; and a correction for a kernel
memory corruption bug if the sysadmin tries to activate a swapfile
with more pages than the swapfile header suggests.
We also now report writeback completion errors to the file mapping
correctly, instead of munging all errors into EIO.
Internally, the bulk of the changes are Christoph's patchset to reduce
the indirect function call count by a third to a half by converting
iomap iteration from a loop pattern to a generator/consumer pattern.
As an added bonus, fsdax no longer open-codes iomap apply loops.
Summary:
- Simplify the bio_end_page usage in the buffered IO code.
- Support reading inline data at nonzero offsets for erofs.
- Fix some typos and bad grammar.
- Convert kmap_atomic usage in the inline data read path.
- Add some extra inline data input checking.
- Fix a memory corruption bug stemming from iomap_swapfile_activate
trying to activate more pages than mm was expecting.
- Pass errnos through the page writeback code so that writeback
errors are reported correctly instead of being munged to EIO.
- Replace iomap_apply with a open-coded iterator loops to reduce the
number of indirect calls by a third to a half.
- Refactor the fsdax code to use iomap iterators instead of the
open-coded iomap_apply code that it had before.
- Format file range iomap tracepoint data in hexadecimal and
standardize the names used in the pretty-print string"
* tag 'iomap-5.15-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (41 commits)
iomap: standardize tracepoint formatting and storage
mm/swap: consider max pages in iomap_swapfile_add_extent
iomap: move loop control code to iter.c
iomap: constify iomap_iter_srcmap
fsdax: switch the fault handlers to use iomap_iter
fsdax: factor out a dax_fault_actor() helper
fsdax: factor out helpers to simplify the dax fault code
iomap: rework unshare flag
iomap: pass an iomap_iter to various buffered I/O helpers
iomap: remove iomap_apply
fsdax: switch dax_iomap_rw to use iomap_iter
iomap: switch iomap_swapfile_activate to use iomap_iter
iomap: switch iomap_seek_data to use iomap_iter
iomap: switch iomap_seek_hole to use iomap_iter
iomap: switch iomap_bmap to use iomap_iter
iomap: switch iomap_fiemap to use iomap_iter
iomap: switch __iomap_dio_rw to use iomap_iter
iomap: switch iomap_page_mkwrite to use iomap_iter
iomap: switch iomap_zero_range to use iomap_iter
iomap: switch iomap_file_unshare to use iomap_iter
...
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Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"The highlights of this round are integrations with fs-verity and
idmapped mounts, the rest is usual mix of minor improvements, speedups
and cleanups.
There are some patches outside of btrfs, namely updating some VFS
interfaces, all straightforward and acked.
Features:
- fs-verity support, using standard ioctls, backward compatible with
read-only limitation on inodes with previously enabled fs-verity
- idmapped mount support
- make mount with rescue=ibadroots more tolerant to partially damaged
trees
- allow raid0 on a single device and raid10 on two devices,
degenerate cases but might be useful as an intermediate step during
conversion to other profiles
- zoned mode block group auto reclaim can be disabled via sysfs knob
Performance improvements:
- continue readahead of node siblings even if target node is in
memory, could speed up full send (on sample test +11%)
- batching of delayed items can speed up creating many files
- fsync/tree-log speedups
- avoid unnecessary work (gains +2% throughput, -2% run time on
sample load)
- reduced lock contention on renames (on dbench +4% throughput,
up to -30% latency)
Fixes:
- various zoned mode fixes
- preemptive flushing threshold tuning, avoid excessive work on
almost full filesystems
Core:
- continued subpage support, preparation for implementing remaining
features like compression and defragmentation; with some
limitations, write is now enabled on 64K page systems with 4K
sectors, still considered experimental
- no readahead on compressed reads
- inline extents disabled
- disabled raid56 profile conversion and mount
- improved flushing logic, fixing early ENOSPC on some workloads
- inode flags have been internally split to read-only and read-write
incompat bit parts, used by fs-verity
- new tree items for fs-verity
- descriptor item
- Merkle tree item
- inode operations extended to be namespace-aware
- cleanups and refactoring
Generic code changes:
- fs: new export filemap_fdatawrite_wbc
- fs: removed sync_inode
- block: bio_trim argument type fixups
- vfs: add namespace-aware lookup"
* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
btrfs: reset replace target device to allocation state on close
btrfs: zoned: fix ordered extent boundary calculation
btrfs: do not do preemptive flushing if the majority is global rsv
btrfs: reduce the preemptive flushing threshold to 90%
btrfs: tree-log: check btrfs_lookup_data_extent return value
btrfs: avoid unnecessarily logging directories that had no changes
btrfs: allow idmapped mount
btrfs: handle ACLs on idmapped mounts
btrfs: allow idmapped INO_LOOKUP_USER ioctl
btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
btrfs: allow idmapped SNAP_DESTROY ioctls
btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
btrfs: check whether fsgid/fsuid are mapped during subvolume creation
btrfs: allow idmapped permission inode op
btrfs: allow idmapped setattr inode op
btrfs: allow idmapped tmpfile inode op
btrfs: allow idmapped symlink inode op
btrfs: allow idmapped mkdir inode op
...
This reverts commit f216562731.
[BUG]
It's no longer possible to create compressed inline extent after commit
f216562731 ("btrfs: compression: don't try to compress if we don't
have enough pages").
[CAUSE]
For compression code, there are several possible reasons we have a range
that needs to be compressed while it's no more than one page.
- Compressed inline write
The data is always smaller than one sector and the test lacks the
condition to properly recognize a non-inline extent.
- Compressed subpage write
For the incoming subpage compressed write support, we require page
alignment of the delalloc range.
And for 64K page size, we can compress just one page into smaller
sectors.
For those reasons, the requirement for the data to be more than one page
is not correct, and is already causing regression for compressed inline
data writeback. The idea of skipping one page to avoid wasting CPU time
could be revisited in the future.
[FIX]
Fix it by reverting the offending commit.
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/afa2742.c084f5d6.17b6b08dffc@tnonline.net
Fixes: f216562731 ("btrfs: compression: don't try to compress if we don't have enough pages")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Creating subvolumes and snapshots is one of the core features of btrfs
and is even available to unprivileged users. Make it possible to use
subvolume and snapshot creation on idmapped mounts. This is a fairly
straightforward operation since all the permission checking helpers are
already capable of handling idmapped mounts. So we just need to pass
down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_permission() to handle idmapped mounts. This is just a
matter of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_setattr() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_tmpfile() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_symlink() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_mkdir() to handle idmapped mounts. This is just a matter of
passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_create() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_mknod() to handle idmapped mounts. This is just a matter of
passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_getattr() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable btrfs_rename() to handle idmapped mounts. This is just a matter
of passing down the mount's userns.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Extend btrfs_new_inode() to take the idmapped mount into account when
initializing a new inode. This is just a matter of passing down the
mount's userns. The rest is taken care of in inode_init_owner(). This is
a preliminary patch to make the individual btrfs inode operations
idmapped mount aware.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We call split_zoned_em() on an extent_map on submitting a bio for it. Thus,
we can assume the extent_map is PINNED, not LOGGING, and in the modified
list. Add ASSERT()s to ensure the extent_maps after the split also has the
proper flags set and are in the modified list.
Suggested-by: Filipe Manana <fdmanana@suse.com>
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>
At the very end of btrfs_rename_exchange(), in case an error happened, we
are checking if 'new_inode' is NULL, but that is not needed since during a
rename exchange, unlike regular renames, 'new_inode' can never be NULL,
and if it were, we would have a crashed much earlier when we dereference it
multiple times.
So remove the check because it is not necessary and because it is causing
static checkers to emit a warning. I probably introduced the check by
copy-pasting similar code from btrfs_rename(), where 'new_inode' can be
NULL, in commit 86e8aa0e77 ("Btrfs: unpin logs if rename exchange
operation fails").
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Writing out the verity data is too large of an operation to do in a
single transaction. If we are interrupted before we finish creating
fsverity metadata for a file, or fail to clean up already created
metadata after a failure, we could leak the verity items that we already
committed.
To address this issue, we use the orphan mechanism. When we start
enabling verity on a file, we also add an orphan item for that inode.
When we are finished, we delete the orphan. However, if we are
interrupted midway, the orphan will be present at mount and we can
cleanup the half-formed verity state.
There is a possible race with a normal unlink operation: if unlink and
verity run on the same file in parallel, it is possible for verity to
succeed and delete the still legitimate orphan added by unlink. Then, if
we are interrupted and mount in that state, we will never clean up the
inode properly. This is also possible for a file created with O_TMPFILE.
Check nlink==0 before deleting to avoid this race.
A final thing to note is that this is a resurrection of using orphans to
signal an operation besides "delete this inode". The old case was to
signal the need to do a truncate. That case still technically applies
for mounting very old file systems, so we need to take some care to not
clobber it. To that end, we just have to be careful that verity orphan
cleanup is a no-op for non-verity files.
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add support for fsverity in btrfs. To support the generic interface in
fs/verity, we add two new item types in the fs tree for inodes with
verity enabled. One stores the per-file verity descriptor and btrfs
verity item and the other stores the Merkle tree data itself.
Verity checking is done in end_page_read just before a page is marked
uptodate. This naturally handles a variety of edge cases like holes,
preallocated extents, and inline extents. Some care needs to be taken to
not try to verity pages past the end of the file, which are accessed by
the generic buffered file reading code under some circumstances like
reading to the end of the last page and trying to read again. Direct IO
on a verity file falls back to buffered reads.
Verity relies on PageChecked for the Merkle tree data itself to avoid
re-walking up shared paths in the tree. For this reason, we need to
cache the Merkle tree data. Since the file is immutable after verity is
turned on, we can cache it at an index past EOF.
Use the new inode ro_flags to store verity on the inode item, so that we
can enable verity on a file, then rollback to an older kernel and still
mount the file system and read the file. Since we can't safely write the
file anymore without ruining the invariants of the Merkle tree, we mark
a ro_compat flag on the file system when a file has verity enabled.
Acked-by: Eric Biggers <ebiggers@google.com>
Co-developed-by: Chris Mason <clm@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, inode flags are fully backwards incompatible in btrfs. If we
introduce a new inode flag, then tree-checker will detect it and fail.
This can even cause us to fail to mount entirely. To make it possible to
introduce new flags which can be read-only compatible, like VERITY, we
add new ro flags to btrfs without treating them quite so harshly in
tree-checker. A read-only file system can survive an unexpected flag,
and can be mounted.
As for the implementation, it unfortunately gets a little complicated.
The on-disk representation of the inode, btrfs_inode_item, has an __le64
for flags but the in-memory representation, btrfs_inode, uses a u32.
David Sterba had the nice idea that we could reclaim those wasted 32 bits
on disk and use them for the new ro_compat flags.
It turns out that the tree-checker code which checks for unknown flags
is broken, and ignores the upper 32 bits we are hoping to use. The issue
is that the flags use the literal 1 rather than 1ULL, so the flags are
signed ints, and one of them is specifically (1 << 31). As a result, the
mask which ORs the flags is a negative integer on machines where int is
32 bit twos complement. When tree-checker evaluates the expression:
btrfs_inode_flags(leaf, iitem) & ~BTRFS_INODE_FLAG_MASK)
The mask is something like 0x80000abc, which gets promoted to u64 with
sign extension to 0xffffffff80000abc. Negating that 64 bit mask leaves
all the upper bits zeroed, and we can't detect unexpected flags.
This suggests that we can't use those bits after all. Luckily, we have
good reason to believe that they are zero anyway. Inode flags are
metadata, which is always checksummed, so any bit flips that would
introduce 1s would cause a checksum failure anyway (excluding the
improbable case of the checksum getting corrupted exactly badly).
Further, unless the 1 << 31 flag is used, the cast to u64 of the 32 bit
inode flag should preserve its value and not add leading zeroes
(at least for twos complement). The only place that flag
(BTRFS_INODE_ROOT_ITEM_INIT) is used is in a special inode embedded in
the root item, and indeed for that inode we see 0xffffffff80000000 as
the flags on disk. However, that inode is never seen by tree checker,
nor is it used in a context where verity might be meaningful.
Theoretically, a future ro flag might cause trouble on that inode, so we
should proactively clean up that mess before it does.
With the introduction of the new ro flags, keep two separate unsigned
masks and check them against the appropriate u32. Since we no longer run
afoul of sign extension, this also stops writing out 0xffffffff80000000
in root_item inodes going forward.
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When btrfs_run_delalloc_range() failed, we will error out.
But there is a strange comment mentioning that
btrfs_run_delalloc_range() could have returned value >0 to indicate the
IO has already started.
Commit 40f765805f ("Btrfs: split up __extent_writepage to lower stack
usage") introduced the comment, but unfortunately at that time, we were
already using @page_started to indicate that case, and still return 0.
Furthermore, even if that comment was right (which is not), we would
return -EIO if the IO had already started.
By all means the comment is incorrect, just remove the comment along
with the dead check.
Just to be extra safe, add an ASSERT() in btrfs_run_delalloc_range() to
make sure we either return 0 or error, no positive return value.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
During renames we pin the logs of the roots a bit too early, before the
calls to btrfs_insert_inode_ref(). We can pin the logs after those calls,
since those will not change anything in a log tree.
In a scenario where we have multiple and diverse filesystem operations
running in parallel, those calls can take a significant amount of time,
due to lock contention on extent buffers, and delay log commits from other
tasks for longer than necessary.
So just pin logs after calls to btrfs_insert_inode_ref() and right before
the first operation that can update a log tree.
The following script that uses dbench was used for testing:
$ cat dbench-test.sh
#!/bin/bash
DEV=/dev/nvme0n1
MNT=/mnt/nvme0n1
MOUNT_OPTIONS="-o ssd"
MKFS_OPTIONS="-m single -d single"
echo "performance" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
umount $DEV &> /dev/null
mkfs.btrfs -f $MKFS_OPTIONS $DEV
mount $MOUNT_OPTIONS $DEV $MNT
dbench -D $MNT -t 120 16
umount $MNT
The tests were run on a machine with 12 cores, 64G of RAN, a NVMe device
and using a non-debug kernel config (Debian's default config).
The results compare a branch without this patch and without the previous
patch in the series, that has the subject:
"btrfs: eliminate some false positives when checking if inode was logged"
Versus the same branch with these two patches applied.
dbench with 8 clients, results before:
Operation Count AvgLat MaxLat
----------------------------------------
NTCreateX 4391359 0.009 249.745
Close 3225882 0.001 3.243
Rename 185953 0.065 240.643
Unlink 886669 0.049 249.906
Deltree 112 2.455 217.433
Mkdir 56 0.002 0.004
Qpathinfo 3980281 0.004 3.109
Qfileinfo 697579 0.001 0.187
Qfsinfo 729780 0.002 2.424
Sfileinfo 357764 0.004 1.415
Find 1538861 0.016 4.863
WriteX 2189666 0.010 3.327
ReadX 6883443 0.002 0.729
LockX 14298 0.002 0.073
UnlockX 14298 0.001 0.042
Flush 307777 2.447 303.663
Throughput 1149.6 MB/sec 8 clients 8 procs max_latency=303.666 ms
dbench with 8 clients, results after:
Operation Count AvgLat MaxLat
----------------------------------------
NTCreateX 4269920 0.009 213.532
Close 3136653 0.001 0.690
Rename 180805 0.082 213.858
Unlink 862189 0.050 172.893
Deltree 112 2.998 218.328
Mkdir 56 0.002 0.003
Qpathinfo 3870158 0.004 5.072
Qfileinfo 678375 0.001 0.194
Qfsinfo 709604 0.002 0.485
Sfileinfo 347850 0.004 1.304
Find 1496310 0.017 5.504
WriteX 2129613 0.010 2.882
ReadX 6693066 0.002 1.517
LockX 13902 0.002 0.075
UnlockX 13902 0.001 0.055
Flush 299276 2.511 220.189
Throughput 1187.33 MB/sec 8 clients 8 procs max_latency=220.194 ms
+3.2% throughput, -31.8% max latency
dbench with 16 clients, results before:
Operation Count AvgLat MaxLat
----------------------------------------
NTCreateX 5978334 0.028 156.507
Close 4391598 0.001 1.345
Rename 253136 0.241 155.057
Unlink 1207220 0.182 257.344
Deltree 160 6.123 36.277
Mkdir 80 0.003 0.005
Qpathinfo 5418817 0.012 6.867
Qfileinfo 949929 0.001 0.941
Qfsinfo 993560 0.002 1.386
Sfileinfo 486904 0.004 2.829
Find 2095088 0.059 8.164
WriteX 2982319 0.017 9.029
ReadX 9371484 0.002 4.052
LockX 19470 0.002 0.461
UnlockX 19470 0.001 0.990
Flush 418936 2.740 347.902
Throughput 1495.31 MB/sec 16 clients 16 procs max_latency=347.909 ms
dbench with 16 clients, results after:
Operation Count AvgLat MaxLat
----------------------------------------
NTCreateX 5711833 0.029 131.240
Close 4195897 0.001 1.732
Rename 241849 0.204 147.831
Unlink 1153341 0.184 231.322
Deltree 160 6.086 30.198
Mkdir 80 0.003 0.021
Qpathinfo 5177011 0.012 7.150
Qfileinfo 907768 0.001 0.793
Qfsinfo 949205 0.002 1.431
Sfileinfo 465317 0.004 2.454
Find 2001541 0.058 7.819
WriteX 2850661 0.017 9.110
ReadX 8952289 0.002 3.991
LockX 18596 0.002 0.655
UnlockX 18596 0.001 0.179
Flush 400342 2.879 293.607
Throughput 1565.73 MB/sec 16 clients 16 procs max_latency=293.611 ms
+4.6% throughput, -16.9% max latency
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When on SINGLE block group, btrfs_get_io_geometry() will return "the
size of the block group - the offset of the logical address within the
block group" as geom.len. Since we allow up to 8 GiB zone size on zoned
filesystem, we can have up to 8 GiB block group, so can have up to 8 GiB
geom.len as well. With this setup, we easily hit the "ASSERT(geom.len <=
INT_MAX);".
The ASSERT looks like to guard btrfs_bio_clone_partial() and bio_trim()
which both take "int" (now u64 due to the previous patch). So to be
precise the ASSERT should check if clone_len <= UINT_MAX. But actually,
clone_len is already capped by bio.bi_iter.bi_size which is unsigned
int. So the ASSERT is not necessary.
Drop the ASSERT and properly compare submit_len and geom.len in u64.
Then, let the implicit casting to convert it to u64.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
sync_inode() has some holes that can cause problems if we're under heavy
ENOSPC pressure. If there's writeback running on a separate thread
sync_inode() will skip writing the inode altogether. What we really
want is to make sure writeback has been started on all the pages to make
sure we can see the ordered extents and wait on them if appropriate.
Switch to this new helper which will allow us to accomplish this and
avoid ENOSPC'ing early.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I've been debugging an early ENOSPC problem in production and finally
root caused it to this problem. When we switched to the per-inode in
38d715f494 ("btrfs: use btrfs_start_delalloc_roots in
shrink_delalloc") I pulled out the async extent handling, because we
were doing the correct thing by calling filemap_flush() if we had async
extents set. This would properly wait on any async extents by locking
the page in the second flush, thus making sure our ordered extents were
properly set up.
However when I switched us back to page based flushing, I used
sync_inode(), which allows us to pass in our own wbc. The problem here
is that sync_inode() is smarter than the filemap_* helpers, it tries to
avoid calling writepages at all. This means that our second call could
skip calling do_writepages altogether, and thus not wait on the pagelock
for the async helpers. This means we could come back before any ordered
extents were created and then simply continue on in our flushing
mechanisms and ENOSPC out when we have plenty of space to use.
Fix this by putting back the async pages logic in shrink_delalloc. This
allows us to bulk write out everything that we need to, and then we can
wait in one place for the async helpers to catch up, and then wait on
any ordered extents that are created.
Fixes: e076ab2a2c ("btrfs: shrink delalloc pages instead of full inodes")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use the async_delalloc_pages mechanism to make sure that we've
completed our async work before trying to continue our delalloc
flushing. The reason for this is we need to see any ordered extents
that were created by our delalloc flushing. However we're waking up
before we do the submit work, which is before we create the ordered
extents. This is a pretty wide race window where we could potentially
think there are no ordered extents and thus exit shrink_delalloc
prematurely. Fix this by waking us up after we've done the work to
create ordered extents.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since now we support data and metadata read-write for subpage, remove
the RO requirement for subpage mount.
There are some extra limitations though:
- For now, subpage RW mount is still considered experimental
Thus that mount warning will still be there.
- No compression support
There are still quite some PAGE_SIZE hard coded and quite some call
sites use extent_clear_unlock_delalloc() to unlock locked_page.
This will screw up subpage helpers.
Now for subpage RW mount, no matter what mount option or inode attr is
set, all writes will not be compressed. Although reading compressed
data has no problem.
- No defrag for subpage case
The defrag support for subpage case will come in later patches, which
will also rework the defrag workflow.
- No inline extent will be created
This is mostly due to the fact that filemap_fdatawrite_range() will
trigger more write than the range specified.
In fallocate calls, this behavior can make us to writeback which can
be inlined, before we enlarge the i_size.
This is a very special corner case, and even current btrfs check won't
report error on such inline extent + regular extent.
But considering how much effort has been put to prevent such inline +
regular, I'd prefer to cut off inline extent completely until we have
a good solution.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When relocating partial preallocated data extents (part of the
preallocated extent is written) for subpage, it can cause the following
false alert and make the relocation to fail:
BTRFS info (device dm-3): balance: start -d
BTRFS info (device dm-3): relocating block group 13631488 flags data
BTRFS warning (device dm-3): csum failed root -9 ino 257 off 4096 csum 0x98757625 expected csum 0x00000000 mirror 1
BTRFS error (device dm-3): bdev /dev/mapper/arm_nvme-test errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
BTRFS warning (device dm-3): csum failed root -9 ino 257 off 4096 csum 0x98757625 expected csum 0x00000000 mirror 1
BTRFS error (device dm-3): bdev /dev/mapper/arm_nvme-test errs: wr 0, rd 0, flush 0, corrupt 2, gen 0
BTRFS info (device dm-3): balance: ended with status: -5
The minimal script to reproduce looks like this:
mkfs.btrfs -f -s 4k $dev
mount $dev -o nospace_cache $mnt
xfs_io -f -c "falloc 0 8k" $mnt/file
xfs_io -f -c "pwrite 0 4k" $mnt/file
btrfs balance start -d $mnt
[CAUSE]
Function btrfs_verify_data_csum() checks if the full range has
EXTENT_NODATASUM bit for data reloc inode, if *all* bytes of the range
have EXTENT_NODATASUM bit, then it skip the range.
This works pretty well for regular sectorsize, as in that case
btrfs_verify_data_csum() is called for each sector, thus no problem at
all.
But for subpage case, btrfs_verify_data_csum() is called on each bvec,
which can contain several sectors, and since it checks *all* bytes for
EXTENT_NODATASUM bit, if we have some range with csum, then we will
continue checking all the sectors.
For the preallocated sectors, it doesn't have any csum, thus obviously
the csum won't match and cause the false alert.
[FIX]
Move the EXTENT_NODATASUM check into the main loop, so that we can check
each sector for EXTENT_NODATASUM bit for subpage case.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a possible use-after-free bug when running generic/095.
BUG: Unable to handle kernel data access on write at 0x6b6b6b6b6b6b725b
Faulting instruction address: 0xc000000000283654
c000000000283078 do_raw_spin_unlock+0x88/0x230
c0000000012b1e14 _raw_spin_unlock_irqrestore+0x44/0x90
c000000000a918dc btrfs_subpage_clear_writeback+0xac/0xe0
c0000000009e0458 end_bio_extent_writepage+0x158/0x270
c000000000b6fd14 bio_endio+0x254/0x270
c0000000009fc0f0 btrfs_end_bio+0x1a0/0x200
c000000000b6fd14 bio_endio+0x254/0x270
c000000000b781fc blk_update_request+0x46c/0x670
c000000000b8b394 blk_mq_end_request+0x34/0x1d0
c000000000d82d1c lo_complete_rq+0x11c/0x140
c000000000b880a4 blk_complete_reqs+0x84/0xb0
c0000000012b2ca4 __do_softirq+0x334/0x680
c0000000001dd878 irq_exit+0x148/0x1d0
c000000000016f4c do_IRQ+0x20c/0x240
c000000000009240 hardware_interrupt_common_virt+0x1b0/0x1c0
[CAUSE]
There is very small race window like the following in generic/095.
Thread 1 | Thread 2
--------------------------------+------------------------------------
end_bio_extent_writepage() | btrfs_releasepage()
|- spin_lock_irqsave() | |
|- end_page_writeback() | |
| | |- if (PageWriteback() ||...)
| | |- clear_page_extent_mapped()
| | |- kfree(subpage);
|- spin_unlock_irqrestore().
The race can also happen between writeback and btrfs_invalidatepage(),
although that would be much harder as btrfs_invalidatepage() has much
more work to do before the clear_page_extent_mapped() call.
[FIX]
Here we "wait" for the subapge spinlock to be released before we detach
subpage structure.
So this patch will introduce a new function, wait_subpage_spinlock(), to
do the "wait" by acquiring the spinlock and release it.
Since the caller has ensured the page is not dirty nor writeback, and
page is already locked, the only way to hold the subpage spinlock is
from endio function.
Thus we only need to acquire the spinlock to wait for any existing
holder.
Reported-by: Ritesh Harjani <riteshh@linux.ibm.com>
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When running the following fsx command (extracted from generic/127) on
subpage filesystem, it can create inline extent with regular extents:
fsx -q -l 262144 -o 65536 -S 191110531 -N 9057 -R -W $mnt/file > /tmp/fsx
The offending extent would look like:
item 9 key (257 INODE_REF 256) itemoff 15703 itemsize 14
index 2 namelen 4 name: file
item 10 key (257 EXTENT_DATA 0) itemoff 14975 itemsize 728
generation 7 type 0 (inline)
inline extent data size 707 ram_bytes 707 compression 0 (none)
item 11 key (257 EXTENT_DATA 4096) itemoff 14922 itemsize 53
generation 7 type 2 (prealloc)
prealloc data disk byte 102346752 nr 4096
prealloc data offset 0 nr 4096
[CAUSE]
For subpage filesystem, the writeback is triggered in page units, which
means, even if we just want to writeback range [16K, 20K) for 64K page
system, we will still try to writeback any dirty sector of range [0, 64K).
This is never a problem if sectorsize == PAGE_SIZE, but for subpage,
this can cause unexpected problems.
For above test case, the last several operations from fsx are:
9055 trunc from 0x40000 to 0x2c3
9057 falloc from 0x164c to 0x19d2 (0x386 bytes)
In operation 9055, we dirtied sector [0, 4096), then in falloc, we call
btrfs_wait_ordered_range(inode, start=4096, len=4096), only expecting to
writeback any dirty data in [4096, 8192), but nothing else.
Unfortunately, in subpage case, above btrfs_wait_ordered_range() will
trigger writeback of the range [0, 64K), which includes the data at
[0, 4096).
And since at the call site, we haven't yet increased i_size, which is
still 707, this means cow_file_range() can insert an inline extent.
Resulting above inline + regular extent.
[WORKAROUND]
I don't really have any good short-term solution yet, as this means all
operations that would trigger writeback need to be reviewed for any
i_size change.
So here I choose to disable inline extent creation for subpage case as a
workaround. We have done tons of work just to avoid such extent, so I
don't to create an exception just for subpage.
This only affects inline extent creation, subpage has no problem reading
existing inline extents at all.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When testing experimental subpage compressed write support, it hits a
NULL pointer dereference inside read path:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
pc : __pi_memcmp+0x28/0x1ec
lr : check_data_csum+0xd0/0x274 [btrfs]
Call trace:
__pi_memcmp+0x28/0x1ec
btrfs_verify_data_csum+0xf4/0x244 [btrfs]
end_bio_extent_readpage+0x1d0/0x6b0 [btrfs]
bio_endio+0x15c/0x1dc
end_workqueue_fn+0x44/0x64 [btrfs]
btrfs_work_helper+0x74/0x250 [btrfs]
process_one_work+0x1d4/0x47c
worker_thread+0x180/0x400
kthread+0x11c/0x120
ret_from_fork+0x10/0x30
Code: 54000261 d100044c d343fd8c f8408403 (f8408424)
---[ end trace 9e2c59f33ea40866 ]---
[CAUSE]
When reading two compressed extents inside the same page, like the
following layout, we trigger above crash:
0 32K 64K
|-------|\\\\\\\|
| \- Compressed extent (A)
\--------- Compressed extent (B)
For compressed read, we don't need to populate its io_bio->csum, as we
rely on compressed_bio->csum to verify the compressed data, and then
copy the decompressed to inode pages.
Normally btrfs_verify_data_csum() skip such page by checking and
clearing its PageChecked flag
But since that flag is still for the full page, when endio for inode
page range [0, 32K) gets executed, it clears PageChecked flag for the
full page.
Then when endio for inode page range [32K, 64K) gets executed, since the
page no longer has PageChecked flag, it just continues checking, even
though io_bio->csum is NULL.
[FIX]
Thankfully there are only two users of PageChecked bit:
- Cow fixup
Since subpage has its own way to trace page dirty (dirty_bitmap) and
ordered bit (ordered_bitmap), it should never trigger cow fixup.
- Compressed read
We can distinguish such read by just checking io_bio->csum.
So just check io_bio->csum before doing the verification to avoid such
NULL pointer dereference.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In commit e65f152e43 ("btrfs: refactor how we finish ordered extent io
for endio functions") there was last caller not using 1 for the uptodate
parameter. Now there's only one, passing 1, so we can remove it and
simplify the code.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit d75855b451 ("btrfs: Remove
extent_io_ops::writepage_start_hook") removes the writepage_start_hook()
and adds btrfs_writepage_cow_fixup() function, there is no need to
follow the old hook parameters.
Remove the @start and @end hook, since currently the fixup check is full
page check, it doesn't need @start and @end hook.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When using the NO_HOLES feature and expanding the size of an inode, we
update the inode's last_trans, last_sub_trans and last_log_commit fields
at maybe_insert_hole() so that a fsync does know that the inode needs to
be logged (by making sure that btrfs_inode_in_log() returns false). This
happens for expanding truncate operations, buffered writes, direct IO
writes and when cloning extents to an offset greater than the inode's
i_size.
However the way we do it is racy, because in between setting the inode's
last_sub_trans and last_log_commit fields, the log transaction ID that was
assigned to last_sub_trans might be committed before we read the root's
last_log_commit and assign that value to last_log_commit. If that happens
it would make a future call to btrfs_inode_in_log() return true. This is
a race that should be extremely unlikely to be hit in practice, and it is
the same that was described by commit bc0939fcfa ("btrfs: fix race
between marking inode needs to be logged and log syncing").
The fix would simply be to set last_log_commit to the value we assigned
to last_sub_trans minus 1, like it was done in that commit. However
updating these two fields plus the last_trans field is pointless here
because all the callers of btrfs_cont_expand() (which is the only
caller of maybe_insert_hole()) always call btrfs_set_inode_last_trans()
or btrfs_update_inode() after calling btrfs_cont_expand(). Calling either
btrfs_set_inode_last_trans() or btrfs_update_inode() guarantees that the
next fsync will log the inode, as it makes btrfs_inode_in_log() return
false.
So just remove the code that explicitly sets the inode's last_trans,
last_sub_trans and last_log_commit fields.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The pages in compressed_pages are not from highmem anymore so we can
drop the mapping for checksum calculation and inline extent.
Signed-off-by: David Sterba <dsterba@suse.com>
Switch __iomap_dio_rw to use iomap_iter.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Cross-rename lacks a check when that would prevent exchanging a
directory and subvolume from different parent subvolume. This causes
data inconsistencies and is caught before commit by tree-checker,
turning the filesystem to read-only.
Calling the renameat2 with RENAME_EXCHANGE flags like
renameat2(AT_FDCWD, namesrc, AT_FDCWD, namedest, (1 << 1))
on two paths:
namesrc = dir1/subvol1/dir2
namedest = subvol2/subvol3
will cause key order problem with following write time tree-checker
report:
[1194842.307890] BTRFS critical (device loop1): corrupt leaf: root=5 block=27574272 slot=10 ino=258, invalid previous key objectid, have 257 expect 258
[1194842.322221] BTRFS info (device loop1): leaf 27574272 gen 8 total ptrs 11 free space 15444 owner 5
[1194842.331562] BTRFS info (device loop1): refs 2 lock_owner 0 current 26561
[1194842.338772] item 0 key (256 1 0) itemoff 16123 itemsize 160
[1194842.338793] inode generation 3 size 16 mode 40755
[1194842.338801] item 1 key (256 12 256) itemoff 16111 itemsize 12
[1194842.338809] item 2 key (256 84 2248503653) itemoff 16077 itemsize 34
[1194842.338817] dir oid 258 type 2
[1194842.338823] item 3 key (256 84 2363071922) itemoff 16043 itemsize 34
[1194842.338830] dir oid 257 type 2
[1194842.338836] item 4 key (256 96 2) itemoff 16009 itemsize 34
[1194842.338843] item 5 key (256 96 3) itemoff 15975 itemsize 34
[1194842.338852] item 6 key (257 1 0) itemoff 15815 itemsize 160
[1194842.338863] inode generation 6 size 8 mode 40755
[1194842.338869] item 7 key (257 12 256) itemoff 15801 itemsize 14
[1194842.338876] item 8 key (257 84 2505409169) itemoff 15767 itemsize 34
[1194842.338883] dir oid 256 type 2
[1194842.338888] item 9 key (257 96 2) itemoff 15733 itemsize 34
[1194842.338895] item 10 key (258 12 256) itemoff 15719 itemsize 14
[1194842.339163] BTRFS error (device loop1): block=27574272 write time tree block corruption detected
[1194842.339245] ------------[ cut here ]------------
[1194842.443422] WARNING: CPU: 6 PID: 26561 at fs/btrfs/disk-io.c:449 csum_one_extent_buffer+0xed/0x100 [btrfs]
[1194842.511863] CPU: 6 PID: 26561 Comm: kworker/u17:2 Not tainted 5.14.0-rc3-git+ #793
[1194842.511870] Hardware name: empty empty/S3993, BIOS PAQEX0-3 02/24/2008
[1194842.511876] Workqueue: btrfs-worker-high btrfs_work_helper [btrfs]
[1194842.511976] RIP: 0010:csum_one_extent_buffer+0xed/0x100 [btrfs]
[1194842.512068] RSP: 0018:ffffa2c284d77da0 EFLAGS: 00010282
[1194842.512074] RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff928867bd9978
[1194842.512078] RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff928867bd9970
[1194842.512081] RBP: ffff92876b958000 R08: 0000000000000001 R09: 00000000000c0003
[1194842.512085] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[1194842.512088] R13: ffff92875f989f98 R14: 0000000000000000 R15: 0000000000000000
[1194842.512092] FS: 0000000000000000(0000) GS:ffff928867a00000(0000) knlGS:0000000000000000
[1194842.512095] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1194842.512099] CR2: 000055f5384da1f0 CR3: 0000000102fe4000 CR4: 00000000000006e0
[1194842.512103] Call Trace:
[1194842.512128] ? run_one_async_free+0x10/0x10 [btrfs]
[1194842.631729] btree_csum_one_bio+0x1ac/0x1d0 [btrfs]
[1194842.631837] run_one_async_start+0x18/0x30 [btrfs]
[1194842.631938] btrfs_work_helper+0xd5/0x1d0 [btrfs]
[1194842.647482] process_one_work+0x262/0x5e0
[1194842.647520] worker_thread+0x4c/0x320
[1194842.655935] ? process_one_work+0x5e0/0x5e0
[1194842.655946] kthread+0x135/0x160
[1194842.655953] ? set_kthread_struct+0x40/0x40
[1194842.655965] ret_from_fork+0x1f/0x30
[1194842.672465] irq event stamp: 1729
[1194842.672469] hardirqs last enabled at (1735): [<ffffffffbd1104f5>] console_trylock_spinning+0x185/0x1a0
[1194842.672477] hardirqs last disabled at (1740): [<ffffffffbd1104cc>] console_trylock_spinning+0x15c/0x1a0
[1194842.672482] softirqs last enabled at (1666): [<ffffffffbdc002e1>] __do_softirq+0x2e1/0x50a
[1194842.672491] softirqs last disabled at (1651): [<ffffffffbd08aab7>] __irq_exit_rcu+0xa7/0xd0
The corrupted data will not be written, and filesystem can be unmounted
and mounted again (all changes since the last commit will be lost).
Add the missing check for new_ino so that all non-subvolumes must reside
under the same parent subvolume. There's an exception allowing to
exchange two subvolumes from any parents as the directory representing a
subvolume is only a logical link and does not have any other structures
related to the parent subvolume, unlike files, directories etc, that
are always in the inode namespace of the parent subvolume.
Fixes: cdd1fedf82 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.7+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Store the block device instead of the gendisk in the btrfs_ordered_extent
structure instead of acquiring a reference to it later.
Note: this is from series removing bdgrab/bdput, btrfs is one of the
last users.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Damien reported a test failure with btrfs/209. The test itself ran fine,
but the fsck ran afterwards reported a corrupted filesystem.
The filesystem corruption happens because we're splitting an extent and
then writing the extent twice. We have to split the extent though, because
we're creating too large extents for a REQ_OP_ZONE_APPEND operation.
When dumping the extent tree, we can see two EXTENT_ITEMs at the same
start address but different lengths.
$ btrfs inspect dump-tree /dev/nullb1 -t extent
...
item 19 key (269484032 EXTENT_ITEM 126976) itemoff 15470 itemsize 53
refs 1 gen 7 flags DATA
extent data backref root FS_TREE objectid 257 offset 786432 count 1
item 20 key (269484032 EXTENT_ITEM 262144) itemoff 15417 itemsize 53
refs 1 gen 7 flags DATA
extent data backref root FS_TREE objectid 257 offset 786432 count 1
The duplicated EXTENT_ITEMs originally come from wrongly split extent_map in
extract_ordered_extent(). Since extract_ordered_extent() uses
create_io_em() to split an existing extent_map, we will have
split->orig_start != split->start. Then, it will be logged with non-zero
"extent data offset". Finally, the logged entries are replayed into
a duplicated EXTENT_ITEM.
Introduce and use proper splitting function for extent_map. The function is
intended to be simple and specific usage for extract_ordered_extent() e.g.
not supporting compression case (we do not allow splitting compressed
extent_map anyway).
There was a question raised by Qu, in summary why we want to split the
extent map (and not the bio):
The problem is not the limit on the zone end, which as you mention is
the same as the block group end. The problem is that data write use zone
append (ZA) operations. ZA BIOs cannot be split so a large extent may
need to be processed with multiple ZA BIOs, While that is also true for
regular writes, the major difference is that ZA are "nameless" write
operation giving back the written sectors on completion. And ZA
operations may be reordered by the block layer (not intentionally
though). Combine both of these characteristics and you can see that the
data for a large extent may end up being shuffled when written resulting
in data corruption and the impossibility to map the extent to some start
sector.
To avoid this problem, zoned btrfs uses the principle "one data extent
== one ZA BIO". So large extents need to be split. This is unfortunate,
but we can revisit this later and optimize, e.g. merge back together the
fragments of an extent once written if they actually were written
sequentially in the zone.
Reported-by: Damien Le Moal <damien.lemoal@wdc.com>
Fixes: d22002fd37 ("btrfs: zoned: split ordered extent when bio is sent")
CC: stable@vger.kernel.org # 5.12+
CC: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The early check if we should attempt compression does not take into
account the number of input pages. It can happen that there's only one
page, eg. a tail page after some ranges of the BTRFS_MAX_UNCOMPRESSED
have been processed, or an isolated page that won't be converted to an
inline extent.
The single page would be compressed but a later check would drop it
again because the result size must be at least one block shorter than
the input. That can never work with just one page.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
With current btrfs subpage rw support, the following script can lead to
fs hang:
$ mkfs.btrfs -f -s 4k $dev
$ mount $dev -o nospace_cache $mnt
$ fsstress -w -n 100 -p 1 -s 1608140256 -v -d $mnt
The fs will hang at btrfs_start_ordered_extent().
[CAUSE]
In above test case, btrfs_invalidate() will be called with the following
parameters:
offset = 0 length = 53248 page dirty = 1 subpage dirty bitmap = 0x2000
Since @offset is 0, btrfs_invalidate() will try to invalidate the full
page, and finally call clear_page_extent_mapped() which will detach
subpage structure from the page.
And since the page no longer has subpage structure, the subpage dirty
bitmap will be cleared, preventing the dirty range from being written
back, thus no way to wake up the ordered extent.
[FIX]
Just follow other filesystems, only to invalidate the page if the range
covers the full page.
There are cases like truncate_setsize() which can call
btrfs_invalidatepage() with offset == 0 and length != 0 for the last
page of an inode.
Although the old code will still try to invalidate the full page, we are
still safe to just wait for ordered extent to finish.
So it shouldn't cause extra problems.
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Only set_page_dirty() and SetPageUptodate() is not subpage compatible.
Convert them to subpage helpers, so that __extent_writepage_io() can
submit page content correctly.
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_truncate_block() itself is already mostly subpage compatible, the
only missing part is the page dirtying code.
Currently if we have a sector that needs to be truncated, we set the
sector aligned range delalloc, then set the full page dirty.
The problem is, current subpage code requires subpage dirty bit to be
set, or __extent_writepage_io() won't submit bio, thus leads to ordered
extent never to finish.
So this patch will make btrfs_truncate_block() to call
btrfs_page_set_dirty() helper to replace set_page_dirty() to fix the
problem.
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function btrfs_set_range_writeback() currently just sets the page
writeback unconditionally.
Change it to call the subpage helper so that we can handle both cases
well.
Since the subpage helpers needs btrfs_fs_info, also change the parameter
to accept btrfs_inode.
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In cow_file_range(), after we have succeeded creating an inline extent,
we unlock the page with extent_clear_unlock_delalloc() by passing
locked_page == NULL.
For sectorsize == PAGE_SIZE case, this is just making the page lock and
unlock harder to grab.
But for incoming subpage case, it can be a big problem.
For incoming subpage case, page locking have two entry points:
- __process_pages_contig()
In that case, we know exactly the range we want to lock (which only
requires sector alignment).
To handle the subpage requirement, we introduce btrfs_subpage::writers
to page::private, and will update it in __process_pages_contig().
- Other directly lock/unlock_page() call sites
Those won't touch btrfs_subpage::writers at all.
This means, page locked by __process_pages_contig() can only be unlocked
by __process_pages_contig().
Thankfully we already have the existing infrastructure in the form of
@locked_page in various call sites.
Unfortunately, extent_clear_unlock_delalloc() in cow_file_range() after
creating an inline extent is the exception.
It intentionally call extent_clear_unlock_delalloc() with locked_page ==
NULL, to also unlock current page (and clear its dirty/writeback bits).
To co-operate with incoming subpage modifications, and make the page
lock/unlock pair easier to understand, this patch will still call
extent_clear_unlock_delalloc() with locked_page, and only unlock the
page in __extent_writepage().
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This involves the following modification:
- Ordered extent creation
This is done in process_one_page(), now PAGE_SET_ORDERED will call
subpage helper to do the work.
- endio functions
This is done in btrfs_mark_ordered_io_finished().
- btrfs_invalidatepage()
- btrfs_cleanup_ordered_extents()
Use the subpage page helper, and add an extra branch to exit if the
locked page have covered the full range.
Now the usage of page Ordered flag for ordered extent accounting is fully
subpage compatible.
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64]
Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When running subpage preparation patches on x86, btrfs/125 will hang
forever with one ordered extent never finished.
[CAUSE]
The test case btrfs/125 itself will always fail as the fix is never merged.
When the test fails at balance, btrfs needs to cleanup the ordered
extent in btrfs_cleanup_ordered_extents() for data reloc inode.
The problem is in the sequence how we cleanup the page Order bit.
Currently it works like:
btrfs_cleanup_ordered_extents()
|- find_get_page();
|- btrfs_page_clear_ordered(page);
| Now the page doesn't have Ordered bit anymore.
| !!! This also includes the first (locked) page !!!
|
|- offset += PAGE_SIZE
| This is to skip the first page
|- __endio_write_update_ordered()
|- btrfs_mark_ordered_io_finished(NULL)
Except the first page, all ordered extents are finished.
Then the locked page is cleaned up in __extent_writepage():
__extent_writepage()
|- If (PageError(page))
|- end_extent_writepage()
|- btrfs_mark_ordered_io_finished(page)
|- if (btrfs_test_page_ordered(page))
|- !!! The page gets skipped !!!
The ordered extent is not decreased as the page doesn't
have ordered bit anymore.
This leaves the ordered extent with bytes_left == sectorsize, thus never
finish.
[FIX]
The fix is to ensure we never clear page Ordered bit without running the
ordered extent accounting.
Here we choose to skip the locked page in
btrfs_cleanup_ordered_extents() so that later end_extent_writepage() can
properly finish the ordered extent.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Inside btrfs we use Private2 page status to indicate we have an ordered
extent with pending IO for the sector.
But the page status name, Private2, tells us nothing about the bit
itself, so this patch will rename it to Ordered.
And with extra comment about the bit added, so reader who is still
uncertain about the page Ordered status, will find the comment pretty
easily.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will refactor btrfs_invalidatepage() for the incoming subpage
support.
The involved modifications are:
- Use while() loop instead of "goto again;"
- Use single variable to determine whether to delete extent states
Each branch will also have comments why we can or cannot delete the
extent states
- Do qgroup free and extent states deletion per-loop
Current code can only work for PAGE_SIZE == sectorsize case.
This refactor also makes it clear what we do for different sectors:
- Sectors without ordered extent
We're completely safe to remove all extent states for the sector(s)
- Sectors with ordered extent, but no Private2 bit
This means the endio has already been executed, we can't remove all
extent states for the sector(s).
- Sectors with ordere extent, still has Private2 bit
This means we need to decrease the ordered extent accounting.
And then it comes to two different variants:
* We have finished and removed the ordered extent
Then it's the same as "sectors without ordered extent"
* We didn't finished the ordered extent
We can remove some extent states, but not all.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The existing comments in btrfs_invalidatepage() don't really get to the
point, especially for what Private2 is really representing and how the
race avoidance is done.
The truth is, there are only three entrances to do ordered extent
accounting:
- btrfs_writepage_endio_finish_ordered()
- __endio_write_update_ordered()
Those two entrance are just endio functions for dio and buffered
write.
- btrfs_invalidatepage()
But there is a pitfall, in endio functions there is no check on whether
the ordered extent is already accounted.
They just blindly clear the Private2 bit and do the accounting.
So it's all btrfs_invalidatepage()'s responsibility to make sure we
won't do double account for the same sector.
That's why in btrfs_invalidatepage() we have to wait for page writeback,
this will ensure all submitted bios have finished, thus their endio
functions have finished the accounting on the ordered extent.
Then we also check page Private2 to ensure that, we only run ordered
extent accounting on pages who has no bio submitted.
This patch will rework related comments to make it more clear on the
race and how we use wait_on_page_writeback() and Private2 to prevent
double accounting on ordered extent.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs has two endio functions to mark certain io range finished for
ordered extents:
- __endio_write_update_ordered()
This is for direct IO
- btrfs_writepage_endio_finish_ordered()
This for buffered IO.
However they go different routines to handle ordered extent io:
- Whether to iterate through all ordered extents
__endio_write_update_ordered() will but
btrfs_writepage_endio_finish_ordered() will not.
In fact, iterating through all ordered extents will benefit later
subpage support, while for current PAGE_SIZE == sectorsize requirement
this behavior makes no difference.
- Whether to update page Private2 flag
__endio_write_update_ordered() will not update page Private2 flag as
for iomap direct IO, the page can not be even mapped.
While btrfs_writepage_endio_finish_ordered() will clear Private2 to
prevent double accounting against btrfs_invalidatepage().
Those differences are pretty subtle, and the ordered extent iterations
code in callers makes code much harder to read.
So this patch will introduce a new function,
btrfs_mark_ordered_io_finished(), to do the heavy lifting:
- Iterate through all ordered extents in the range
- Do the ordered extent accounting
- Queue the work for finished ordered extent
This function has two new feature:
- Proper underflow detection and recovery
The old underflow detection will only detect the problem, then
continue.
No proper info like root/inode/ordered extent info, nor noisy enough
to be caught by fstests.
Furthermore when underflow happens, the ordered extent will never
finish.
New error detection will reset the bytes_left to 0, do proper
kernel warning, and output extra info including root, ino, ordered
extent range, the underflow value.
- Prevent double accounting based on Private2 flag
Now if we find a range without Private2 flag, we will skip to next
range.
As that means someone else has already finished the accounting of
ordered extent.
This makes no difference for current code, but will be a critical part
for incoming subpage support, as we can call
btrfs_mark_ordered_io_finished() for multiple sectors if they are
beyond inode size.
Thus such double accounting prevention is a key feature for subpage.
Now both endio functions only need to call that new function.
And since the only caller of btrfs_dec_test_first_ordered_pending() is
removed, also remove btrfs_dec_test_first_ordered_pending() completely.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we use page Private2 bit to indicate that we have ordered
extent for the page range.
But the lifespan of it is not consistent, during regular writeback path,
there are two locations to clear the same PagePrivate2:
T ----- Page marked Dirty
|
+ ----- Page marked Private2, through btrfs_run_dealloc_range()
|
+ ----- Page cleared Private2, through btrfs_writepage_cow_fixup()
| in __extent_writepage_io()
| ^^^ Private2 cleared for the first time
|
+ ----- Page marked Writeback, through btrfs_set_range_writeback()
| in __extent_writepage_io().
|
+ ----- Page cleared Private2, through
| btrfs_writepage_endio_finish_ordered()
| ^^^ Private2 cleared for the second time.
|
+ ----- Page cleared Writeback, through
btrfs_writepage_endio_finish_ordered()
Currently PagePrivate2 is mostly to prevent ordered extent accounting
being executed for both endio and invalidatepage.
Thus only the one who cleared page Private2 is responsible for ordered
extent accounting.
But the fact is, in btrfs_writepage_endio_finish_ordered(), page
Private2 is cleared and ordered extent accounting is executed
unconditionally.
The race prevention only happens through btrfs_invalidatepage(), where
we wait for the page writeback first, before checking the Private2 bit.
This means, Private2 is also protected by Writeback bit, and there is no
need for btrfs_writepage_cow_fixup() to clear Priavte2.
This patch will change btrfs_writepage_cow_fixup() to just check
PagePrivate2, not to clear it.
The clearing will happen in either btrfs_invalidatepage() or
btrfs_writepage_endio_finish_ordered().
This makes the Private2 bit easier to understand, just meaning the page
has unfinished ordered extent attached to it.
And this patch is a hard requirement for the incoming refactoring for
how we finished ordered IO for endio context, as the coming patch will
check Private2 to determine if we need to do the ordered extent
accounting. Thus this patch is definitely needed or we will hang due to
unfinished ordered extent.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a pretty bad abuse of btrfs_writepage_endio_finish_ordered() in
end_compressed_bio_write().
It passes compressed pages to btrfs_writepage_endio_finish_ordered(),
which is only supposed to accept inode pages.
Thankfully the important info here is the inode, so let's pass
btrfs_inode directly into btrfs_writepage_endio_finish_ordered(), and
make @page parameter optional.
By this, end_compressed_bio_write() can happily pass page=NULL while
still getting everything done properly.
Also, to cooperate with such modification, replace @page parameter for
trace_btrfs_writepage_end_io_hook() with btrfs_inode.
Although this removes page_index info, the existing start/len should be
enough for most usage.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a lot of code inside extent_io.c needs both "struct bio
**bio_ret" and "unsigned long prev_bio_flags", along with some
parameters like "unsigned long bio_flags".
Such strange parameters are here for bio assembly.
For example, we have such inode page layout:
0 4K 8K 12K
|<-- Extent A-->|<- EB->|
Then what we do is:
- Page [0, 4K)
*bio_ret = NULL
So we allocate a new bio to bio_ret,
Add page [0, 4K) to *bio_ret.
- Page [4K, 8K)
*bio_ret != NULL
We found this page is continuous to *bio_ret,
and if we're not at stripe boundary, we
add page [4K, 8K) to *bio_ret.
- Page [8K, 12K)
*bio_ret != NULL
But we found this page is not continuous, so
we submit *bio_ret, then allocate a new bio,
and add page [8K, 12K) to the new bio.
This means we need to record both the bio and its bio_flag, but we
record them manually using those strange parameter list, other than
encapsulating them into their own structure.
So this patch will introduce a new structure, btrfs_bio_ctrl, to record
both the bio, and its bio_flags.
Also, in above case, for all pages added to the bio, we need to check if
the new page crosses stripe boundary. This check itself can be time
consuming, and we don't really need to do that for each page.
This patch also integrates the stripe boundary check into btrfs_bio_ctrl.
When a new bio is allocated, the stripe and ordered extent boundary is
also calculated, so no matter how large the bio will be, we only
calculate the boundaries once, to save some CPU time.
The following functions/structures are affected:
- struct extent_page_data
Replace its bio pointer with structure btrfs_bio_ctrl (embedded
structure, not pointer)
- end_write_bio()
- flush_write_bio()
Just change how bio is fetched
- btrfs_bio_add_page()
Use pre-calculated boundaries instead of re-calculating them.
And use @bio_ctrl to replace @bio and @prev_bio_flags.
- calc_bio_boundaries()
New function
- submit_extent_page() callers
- btrfs_do_readpage() callers
- contiguous_readpages() callers
To Use @bio_ctrl to replace @bio and @prev_bio_flags, and how to grab
bio.
- btrfs_bio_fits_in_ordered_extent()
Removed, as now the ordered extent size limit is done at bio
allocation time, no need to check for each page range.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function btrfs_bio_fits_in_stripe() now requires a bio with at least one
page added. Or btrfs_get_chunk_map() will fail with -ENOENT.
But in fact this requirement is not needed at all, as we can just pass
sectorsize for btrfs_get_chunk_map().
This tiny behavior change is important for later subpage refactoring on
submit_extent_page().
As for 64K page size, we can have a page range with pgoff=0 and size=64K.
If the logical bytenr is just 16K before the stripe boundary, we have to
split the page range into two bios.
This means, we must check page range against stripe boundary, even adding
the range to an empty bio.
This tiny refactoring is for the incoming changes, but on its own,
regular sectorsize == PAGE_SIZE is not affected anyway.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter @len is not really used in btrfs_bio_fits_in_stripe(),
just remove it.
It got removed in 4203431319 ("btrfs: let callers of
btrfs_get_io_geometry pass the em"), before that btrfs_get_chunk_map
utilized it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_truncate() where we truncate the inode either to the same size
or to a smaller size, we always set the full sync flag on the inode.
This is needed in case the truncation drops or trims any file extent items
that start beyond or cross the new inode size, so that the next fsync
drops all inode items from the log and scans again the fs/subvolume tree
to find all items that must be logged.
However if the truncation does not drop or trims any file extent items, we
do not need to set the full sync flag and force the next fsync to use the
slow code path. So do not set the full sync flag in such cases.
One use case where it is frequent to do truncations that do not change
the inode size and do not drop any extents (no prealloc extents beyond
i_size) is when running Microsoft's SQL Server inside a Docker container.
One example workload is the one Philipp Fent reported recently, in the
thread with a link below. In this workload a large number of fsyncs are
preceded by such truncate operations.
After this change I constantly get the runtime for that workload from
Philipp to be reduced by about -12%, for example from 184 seconds down
to 162 seconds.
Link: https://lore.kernel.org/linux-btrfs/93c4600e-5263-5cba-adf0-6f47526e7561@in.tum.de/
Tested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The comment at the top of btrfs_truncate() mentions that csum items are
dropped or truncated to the new i_size, but this is wrong and non sense,
as they are unrelated to the i_size and are located in the csums tree and
not on a tree with inode items (fs/subvolume tree or a log tree). Instead
that claim applies to file extent items, so fix the comment to refer to
them instead.
While at it make the whole comment for the function more descriptive and
follow the kernel doc style.
Tested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_submit_read_repair() has some extra check on whether the
failed bio needs extra validation for repair. But we can avoid all
these extra mechanisms if we submit the repair for each sector.
By this, each read repair can be easily handled without the need to
verify which sector is corrupted.
This will also benefit subpage, as one subpage bvec can contain several
sectors, making the extra verification more complex.
So this patch will:
- Introduce repair_one_sector()
The main code submitting repair, which is more or less the same as old
btrfs_submit_read_repair().
But this time, it only repairs one sector.
- Make btrfs_submit_read_repair() to handle sectors differently
There are 3 different cases:
* Good sector
We need to release the page and extent, set the range uptodate.
* Bad sector and failed to submit repair bio
We need to release the page and extent, but not set the range
uptodate.
* Bad sector but repair bio submitted
The page and extent release will be handled by the submitted repair
bio. Nothing needs to be done.
Since btrfs_submit_read_repair() will handle the page and extent
release now, we need to skip to next bvec even we hit some error.
- Change the lifespan of @uptodate in end_bio_extent_readpage()
Since now btrfs_submit_read_repair() will handle the full bvec
which contains any corruption, we don't need to bother updating
@uptodate bit anymore.
Just let @uptodate to be local variable inside the main loop,
so that any error from one bvec won't affect later bvec.
- Only export btrfs_repair_one_sector(), unexport
btrfs_submit_read_repair()
The only outside caller for read repair is DIO, which already submits
its repair for just one sector.
Only export btrfs_repair_one_sector() for DIO.
This patch will focus on the change on the repair path, the extra
validation code is still kept as is, and will be cleaned up later.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This will provide the basis for later per-sector repair for subpage,
while still keeping the existing code happy.
As if all csums match, the return value will be 0, same as now.
Only when csum mismatches, the return value is different.
The new return value will be a bitmap, for 4K sectorsize and 4K page
size, it will be either 1, instead of the -EIO (which is not used
directly by the callers, no effective change).
But for 4K sectorsize and 64K page size, aka subpage case, since the
bvec can contain multiple sectors, knowing which sectors are corrupted
will allow us to submit repair only for corrupted sectors.
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-5.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Error handling improvements, caught by error injection:
- handle errors during checksum deletion
- set error on mapping when ordered extent io cannot be finished
- inode link count fixup in tree-log
- missing return value checks for inode updates in tree-log
- abort transaction in rename exchange if adding second reference
fails
Fixes:
- fix fsync failure after writes to prealloc extents
- fix deadlock when cloning inline extents and low on available space
- fix compressed writes that cross stripe boundary"
* tag 'for-5.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
MAINTAINERS: add btrfs IRC link
btrfs: fix deadlock when cloning inline extents and low on available space
btrfs: fix fsync failure and transaction abort after writes to prealloc extents
btrfs: abort in rename_exchange if we fail to insert the second ref
btrfs: check error value from btrfs_update_inode in tree log
btrfs: fixup error handling in fixup_inode_link_counts
btrfs: mark ordered extent and inode with error if we fail to finish
btrfs: return errors from btrfs_del_csums in cleanup_ref_head
btrfs: fix error handling in btrfs_del_csums
btrfs: fix compressed writes that cross stripe boundary
Error injection stress uncovered a problem where we'd leave a dangling
inode ref if we failed during a rename_exchange. This happens because
we insert the inode ref for one side of the rename, and then for the
other side. If this second inode ref insert fails we'll leave the first
one dangling and leave a corrupt file system behind. Fix this by
aborting if we did the insert for the first inode ref.
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While doing error injection testing I saw that sometimes we'd get an
abort that wouldn't stop the current transaction commit from completing.
This abort was coming from finish ordered IO, but at this point in the
transaction commit we should have gotten an error and stopped.
It turns out the abort came from finish ordered io while trying to write
out the free space cache. It occurred to me that any failure inside of
finish_ordered_io isn't actually raised to the person doing the writing,
so we could have any number of failures in this path and think the
ordered extent completed successfully and the inode was fine.
Fix this by marking the ordered extent with BTRFS_ORDERED_IOERR, and
marking the mapping of the inode with mapping_set_error, so any callers
that simply call fdatawait will also get the error.
With this we're seeing the IO error on the free space inode when we fail
to do the finish_ordered_io.
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_use_zone_append only needs the passed in extent_map's block_start
member, so there's no need to pass in the full extent map.
This also enables the use of btrfs_use_zone_append in places where we only
have a start byte but no extent_map.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more fixes:
- fix fiemap to print extents that could get misreported due to
internal extent splitting and logical merging for fiemap output
- fix RCU stalls during delayed iputs
- fix removed dentries still existing after log is synced"
* tag 'for-5.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix removed dentries still existing after log is synced
btrfs: return whole extents in fiemap
btrfs: avoid RCU stalls while running delayed iputs
btrfs: return 0 for dev_extent_hole_check_zoned hole_start in case of error
Generally a delayed iput is added when we might do the final iput, so
usually we'll end up sleeping while processing the delayed iputs
naturally. However there's no guarantee of this, especially for small
files. In production we noticed 5 instances of RCU stalls while testing
a kernel release overnight across 1000 machines, so this is relatively
common:
host count: 5
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: ....: (20998 ticks this GP) idle=59e/1/0x4000000000000002 softirq=12333372/12333372 fqs=3208
(t=21031 jiffies g=27810193 q=41075) NMI backtrace for cpu 1
CPU: 1 PID: 1713 Comm: btrfs-cleaner Kdump: loaded Not tainted 5.6.13-0_fbk12_rc1_5520_gec92bffc1ec9 #1
Call Trace:
<IRQ> dump_stack+0x50/0x70
nmi_cpu_backtrace.cold.6+0x30/0x65
? lapic_can_unplug_cpu.cold.30+0x40/0x40
nmi_trigger_cpumask_backtrace+0xba/0xca
rcu_dump_cpu_stacks+0x99/0xc7
rcu_sched_clock_irq.cold.90+0x1b2/0x3a3
? trigger_load_balance+0x5c/0x200
? tick_sched_do_timer+0x60/0x60
? tick_sched_do_timer+0x60/0x60
update_process_times+0x24/0x50
tick_sched_timer+0x37/0x70
__hrtimer_run_queues+0xfe/0x270
hrtimer_interrupt+0xf4/0x210
smp_apic_timer_interrupt+0x5e/0x120
apic_timer_interrupt+0xf/0x20 </IRQ>
RIP: 0010:queued_spin_lock_slowpath+0x17d/0x1b0
RSP: 0018:ffffc9000da5fe48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff889fa81d0cd8 RCX: 0000000000000029
RDX: ffff889fff86c0c0 RSI: 0000000000080000 RDI: ffff88bfc2da7200
RBP: ffff888f2dcdd768 R08: 0000000001040000 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff82a55560 R12: ffff88bfc2da7200
R13: 0000000000000000 R14: ffff88bff6c2a360 R15: ffffffff814bd870
? kzalloc.constprop.57+0x30/0x30
list_lru_add+0x5a/0x100
inode_lru_list_add+0x20/0x40
iput+0x1c1/0x1f0
run_delayed_iput_locked+0x46/0x90
btrfs_run_delayed_iputs+0x3f/0x60
cleaner_kthread+0xf2/0x120
kthread+0x10b/0x130
Fix this by adding a cond_resched_lock() to the loop processing delayed
iputs so we can avoid these sort of stalls.
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"First batch of various fixes, here's a list of notable ones:
- fix unmountable seed device after fstrim
- fix silent data loss in zoned mode due to ordered extent splitting
- fix race leading to unpersisted data and metadata on fsync
- fix deadlock when cloning inline extents and using qgroups"
* tag 'for-5.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: initialize return variable in cleanup_free_space_cache_v1
btrfs: zoned: sanity check zone type
btrfs: fix unmountable seed device after fstrim
btrfs: fix deadlock when cloning inline extents and using qgroups
btrfs: fix race leading to unpersisted data and metadata on fsync
btrfs: do not consider send context as valid when trying to flush qgroups
btrfs: zoned: fix silent data loss after failure splitting ordered extent
There are many places where kmap/memset/kunmap patterns occur.
Use the newly lifted memzero_page() to eliminate direct uses of kmap and
leverage the new core functions use of kmap_local_page().
The development of this patch was aided by the following coccinelle
script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap/memset/kunmap pattern and replace with memset*page calls
//
// NOTE: Offsets and other expressions may be more complex than what the script
// will automatically generate. Therefore a catchall rule is provided to find
// the pattern which then must be evaluated by hand.
//
// Confidence: Low
// Copyright: (C) 2021 Intel Corporation
// URL: http://coccinelle.lip6.fr/
// Comments:
// Options:
//
// Then the memset pattern
//
@ memset_rule1 @
expression page, V, L, Off;
identifier ptr;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
-memset(ptr, 0, L);
+memzero_page(page, 0, L);
|
-memset(ptr + Off, 0, L);
+memzero_page(page, Off, L);
|
-memset(ptr, V, L);
+memset_page(page, V, 0, L);
|
-memset(ptr + Off, V, L);
+memset_page(page, V, Off, L);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memset_rule1
@
identifier memset_rule1.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
//
// Catch all
//
@ memset_rule2 @
expression page;
identifier ptr;
expression GenTo, GenSize, GenValue;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
//
// Some call sites have complex expressions within the memset/memcpy
// The follow are catch alls which need to be evaluated by hand.
//
-memset(GenTo, 0, GenSize);
+memzero_pageExtra(page, GenTo, GenSize);
|
-memset(GenTo, GenValue, GenSize);
+memset_pageExtra(page, GenValue, GenTo, GenSize);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memset_rule2
@
identifier memset_rule2.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
// </smpl>
Link: https://lkml.kernel.org/r/20210309212137.2610186-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are a few exceptional cases where cloning an inline extent needs to
copy the inline extent data into a page of the destination inode.
When this happens, we end up starting a transaction while having a dirty
page for the destination inode and while having the range locked in the
destination's inode iotree too. Because when reserving metadata space
for a transaction we may need to flush existing delalloc in case there is
not enough free space, we have a mechanism in place to prevent a deadlock,
which was introduced in commit 3d45f221ce ("btrfs: fix deadlock when
cloning inline extent and low on free metadata space").
However when using qgroups, a transaction also reserves metadata qgroup
space, which can also result in flushing delalloc in case there is not
enough available space at the moment. When this happens we deadlock, since
flushing delalloc requires locking the file range in the inode's iotree
and the range was already locked at the very beginning of the clone
operation, before attempting to start the transaction.
When this issue happens, stack traces like the following are reported:
[72747.556262] task:kworker/u81:9 state:D stack: 0 pid: 225 ppid: 2 flags:0x00004000
[72747.556268] Workqueue: writeback wb_workfn (flush-btrfs-1142)
[72747.556271] Call Trace:
[72747.556273] __schedule+0x296/0x760
[72747.556277] schedule+0x3c/0xa0
[72747.556279] io_schedule+0x12/0x40
[72747.556284] __lock_page+0x13c/0x280
[72747.556287] ? generic_file_readonly_mmap+0x70/0x70
[72747.556325] extent_write_cache_pages+0x22a/0x440 [btrfs]
[72747.556331] ? __set_page_dirty_nobuffers+0xe7/0x160
[72747.556358] ? set_extent_buffer_dirty+0x5e/0x80 [btrfs]
[72747.556362] ? update_group_capacity+0x25/0x210
[72747.556366] ? cpumask_next_and+0x1a/0x20
[72747.556391] extent_writepages+0x44/0xa0 [btrfs]
[72747.556394] do_writepages+0x41/0xd0
[72747.556398] __writeback_single_inode+0x39/0x2a0
[72747.556403] writeback_sb_inodes+0x1ea/0x440
[72747.556407] __writeback_inodes_wb+0x5f/0xc0
[72747.556410] wb_writeback+0x235/0x2b0
[72747.556414] ? get_nr_inodes+0x35/0x50
[72747.556417] wb_workfn+0x354/0x490
[72747.556420] ? newidle_balance+0x2c5/0x3e0
[72747.556424] process_one_work+0x1aa/0x340
[72747.556426] worker_thread+0x30/0x390
[72747.556429] ? create_worker+0x1a0/0x1a0
[72747.556432] kthread+0x116/0x130
[72747.556435] ? kthread_park+0x80/0x80
[72747.556438] ret_from_fork+0x1f/0x30
[72747.566958] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[72747.566961] Call Trace:
[72747.566964] __schedule+0x296/0x760
[72747.566968] ? finish_wait+0x80/0x80
[72747.566970] schedule+0x3c/0xa0
[72747.566995] wait_extent_bit.constprop.68+0x13b/0x1c0 [btrfs]
[72747.566999] ? finish_wait+0x80/0x80
[72747.567024] lock_extent_bits+0x37/0x90 [btrfs]
[72747.567047] btrfs_invalidatepage+0x299/0x2c0 [btrfs]
[72747.567051] ? find_get_pages_range_tag+0x2cd/0x380
[72747.567076] __extent_writepage+0x203/0x320 [btrfs]
[72747.567102] extent_write_cache_pages+0x2bb/0x440 [btrfs]
[72747.567106] ? update_load_avg+0x7e/0x5f0
[72747.567109] ? enqueue_entity+0xf4/0x6f0
[72747.567134] extent_writepages+0x44/0xa0 [btrfs]
[72747.567137] ? enqueue_task_fair+0x93/0x6f0
[72747.567140] do_writepages+0x41/0xd0
[72747.567144] __filemap_fdatawrite_range+0xc7/0x100
[72747.567167] btrfs_run_delalloc_work+0x17/0x40 [btrfs]
[72747.567195] btrfs_work_helper+0xc2/0x300 [btrfs]
[72747.567200] process_one_work+0x1aa/0x340
[72747.567202] worker_thread+0x30/0x390
[72747.567205] ? create_worker+0x1a0/0x1a0
[72747.567208] kthread+0x116/0x130
[72747.567211] ? kthread_park+0x80/0x80
[72747.567214] ret_from_fork+0x1f/0x30
[72747.569686] task:fsstress state:D stack: 0 pid:841421 ppid:841417 flags:0x00000000
[72747.569689] Call Trace:
[72747.569691] __schedule+0x296/0x760
[72747.569694] schedule+0x3c/0xa0
[72747.569721] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569725] ? finish_wait+0x80/0x80
[72747.569753] btrfs_qgroup_reserve_data+0x34/0x50 [btrfs]
[72747.569781] btrfs_check_data_free_space+0x5f/0xa0 [btrfs]
[72747.569804] btrfs_buffered_write+0x1f7/0x7f0 [btrfs]
[72747.569810] ? path_lookupat.isra.48+0x97/0x140
[72747.569833] btrfs_file_write_iter+0x81/0x410 [btrfs]
[72747.569836] ? __kmalloc+0x16a/0x2c0
[72747.569839] do_iter_readv_writev+0x160/0x1c0
[72747.569843] do_iter_write+0x80/0x1b0
[72747.569847] vfs_writev+0x84/0x140
[72747.569869] ? btrfs_file_llseek+0x38/0x270 [btrfs]
[72747.569873] do_writev+0x65/0x100
[72747.569876] do_syscall_64+0x33/0x40
[72747.569879] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[72747.569899] task:fsstress state:D stack: 0 pid:841424 ppid:841417 flags:0x00004000
[72747.569903] Call Trace:
[72747.569906] __schedule+0x296/0x760
[72747.569909] schedule+0x3c/0xa0
[72747.569936] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569940] ? finish_wait+0x80/0x80
[72747.569967] __btrfs_qgroup_reserve_meta+0x36/0x50 [btrfs]
[72747.569989] start_transaction+0x279/0x580 [btrfs]
[72747.570014] clone_copy_inline_extent+0x332/0x490 [btrfs]
[72747.570041] btrfs_clone+0x5b7/0x7a0 [btrfs]
[72747.570068] ? lock_extent_bits+0x64/0x90 [btrfs]
[72747.570095] btrfs_clone_files+0xfc/0x150 [btrfs]
[72747.570122] btrfs_remap_file_range+0x3d8/0x4a0 [btrfs]
[72747.570126] do_clone_file_range+0xed/0x200
[72747.570131] vfs_clone_file_range+0x37/0x110
[72747.570134] ioctl_file_clone+0x7d/0xb0
[72747.570137] do_vfs_ioctl+0x138/0x630
[72747.570140] __x64_sys_ioctl+0x62/0xc0
[72747.570143] do_syscall_64+0x33/0x40
[72747.570146] entry_SYSCALL_64_after_hwframe+0x44/0xa9
So fix this by skipping the flush of delalloc for an inode that is
flagged with BTRFS_INODE_NO_DELALLOC_FLUSH, meaning it is currently under
such a special case of cloning an inline extent, when flushing delalloc
during qgroup metadata reservation.
The special cases for cloning inline extents were added in kernel 5.7 by
by commit 05a5a7621c ("Btrfs: implement full reflink support for
inline extents"), while having qgroup metadata space reservation flushing
delalloc when low on space was added in kernel 5.9 by commit
c53e965360 ("btrfs: qgroup: try to flush qgroup space when we get
-EDQUOT"). So use a "Fixes:" tag for the later commit to ease stable
kernel backports.
Reported-by: Wang Yugui <wangyugui@e16-tech.com>
Link: https://lore.kernel.org/linux-btrfs/20210421083137.31E3.409509F4@e16-tech.com/
Fixes: c53e965360 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.9+
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>
Pull fileattr conversion updates from Miklos Szeredi via Al Viro:
"This splits the handling of FS_IOC_[GS]ETFLAGS from ->ioctl() into a
separate method.
The interface is reasonably uniform across the filesystems that
support it and gives nice boilerplate removal"
* 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits)
ovl: remove unneeded ioctls
fuse: convert to fileattr
fuse: add internal open/release helpers
fuse: unsigned open flags
fuse: move ioctl to separate source file
vfs: remove unused ioctl helpers
ubifs: convert to fileattr
reiserfs: convert to fileattr
ocfs2: convert to fileattr
nilfs2: convert to fileattr
jfs: convert to fileattr
hfsplus: convert to fileattr
efivars: convert to fileattr
xfs: convert to fileattr
orangefs: convert to fileattr
gfs2: convert to fileattr
f2fs: convert to fileattr
ext4: convert to fileattr
ext2: convert to fileattr
btrfs: convert to fileattr
...
btrfs_record_root_in_trans will return errors in the future, so handle
the error properly in btrfs_delete_subvolume.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_record_root_in_trans will return errors in the future, so handle
the error properly in btrfs_rename.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_record_root_in_trans will return errors in the future, so handle
the error properly in btrfs_rename_exchange.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_invalidatepage() we re-declare @tree variable as
btrfs_ordered_inode_tree.
Since it's only used to do the spinlock, we can grab it from inode
directly, and remove the unnecessary declaration completely.
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>
In btrfs_invalidatepage() we introduce a temporary variable, new_len, to
update ordered->truncated_len. But we can use min() to replace it
completely and no need for the variable.
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>
btrfs_orphan_cleanup() has a comment referring to find_dead_roots, but
function does not exists since commit cb517eabba ("Btrfs: cleanup the
similar code of the fs root read"). What we use now to find and load dead
roots is btrfs_find_orphan_roots(). So update the comment and make it a
bit more detailed about why we can not delete an orphan item for a root.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use a simple coccinelle script to help convert the most common
kmap()/kunmap() patterns to kmap_local_page()/kunmap_local().
Note that some kmaps which were caught by this script needed to be
handled by hand because of the strict unmapping order of kunmap_local()
so they are not included in this patch. But this script got us started.
There's another temp variable added for the final length write to the
first page so it does not interfere with cpage_out that is used for
mapping other pages.
The development of this patch was aided by the follow script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap and replace with kmap_local_page then mark kunmap
//
// Confidence: Low
// Copyright: (C) 2021 Intel Corporation
// URL: http://coccinelle.lip6.fr/
@ catch_all @
expression e, e2;
@@
(
-kmap(e)
+kmap_local_page(e)
)
...
(
-kunmap(...)
+kunmap_local()
)
// </smpl>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a race between marking that an inode needs to be logged, either
at btrfs_set_inode_last_trans() or at btrfs_page_mkwrite(), and between
btrfs_sync_log(). The following steps describe how the race happens.
1) We are at transaction N;
2) Inode I was previously fsynced in the current transaction so it has:
inode->logged_trans set to N;
3) The inode's root currently has:
root->log_transid set to 1
root->last_log_commit set to 0
Which means only one log transaction was committed to far, log
transaction 0. When a log tree is created we set ->log_transid and
->last_log_commit of its parent root to 0 (at btrfs_add_log_tree());
4) One more range of pages is dirtied in inode I;
5) Some task A starts an fsync against some other inode J (same root), and
so it joins log transaction 1.
Before task A calls btrfs_sync_log()...
6) Task B starts an fsync against inode I, which currently has the full
sync flag set, so it starts delalloc and waits for the ordered extent
to complete before calling btrfs_inode_in_log() at btrfs_sync_file();
7) During ordered extent completion we have btrfs_update_inode() called
against inode I, which in turn calls btrfs_set_inode_last_trans(),
which does the following:
spin_lock(&inode->lock);
inode->last_trans = trans->transaction->transid;
inode->last_sub_trans = inode->root->log_transid;
inode->last_log_commit = inode->root->last_log_commit;
spin_unlock(&inode->lock);
So ->last_trans is set to N and ->last_sub_trans set to 1.
But before setting ->last_log_commit...
8) Task A is at btrfs_sync_log():
- it increments root->log_transid to 2
- starts writeback for all log tree extent buffers
- waits for the writeback to complete
- writes the super blocks
- updates root->last_log_commit to 1
It's a lot of slow steps between updating root->log_transid and
root->last_log_commit;
9) The task doing the ordered extent completion, currently at
btrfs_set_inode_last_trans(), then finally runs:
inode->last_log_commit = inode->root->last_log_commit;
spin_unlock(&inode->lock);
Which results in inode->last_log_commit being set to 1.
The ordered extent completes;
10) Task B is resumed, and it calls btrfs_inode_in_log() which returns
true because we have all the following conditions met:
inode->logged_trans == N which matches fs_info->generation &&
inode->last_subtrans (1) <= inode->last_log_commit (1) &&
inode->last_subtrans (1) <= root->last_log_commit (1) &&
list inode->extent_tree.modified_extents is empty
And as a consequence we return without logging the inode, so the
existing logged version of the inode does not point to the extent
that was written after the previous fsync.
It should be impossible in practice for one task be able to do so much
progress in btrfs_sync_log() while another task is at
btrfs_set_inode_last_trans() right after it reads root->log_transid and
before it reads root->last_log_commit. Even if kernel preemption is enabled
we know the task at btrfs_set_inode_last_trans() can not be preempted
because it is holding the inode's spinlock.
However there is another place where we do the same without holding the
spinlock, which is in the memory mapped write path at:
vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
(...)
BTRFS_I(inode)->last_trans = fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
(...)
So with preemption happening after setting ->last_sub_trans and before
setting ->last_log_commit, it is less of a stretch to have another task
do enough progress at btrfs_sync_log() such that the task doing the memory
mapped write ends up with ->last_sub_trans and ->last_log_commit set to
the same value. It is still a big stretch to get there, as the task doing
btrfs_sync_log() has to start writeback, wait for its completion and write
the super blocks.
So fix this in two different ways:
1) For btrfs_set_inode_last_trans(), simply set ->last_log_commit to the
value of ->last_sub_trans minus 1;
2) For btrfs_page_mkwrite() only set the inode's ->last_sub_trans, just
like we do for buffered and direct writes at btrfs_file_write_iter(),
which is all we need to make sure multiple writes and fsyncs to an
inode in the same transaction never result in an fsync missing that
the inode changed and needs to be logged. Turn this into a helper
function and use it both at btrfs_page_mkwrite() and at
btrfs_file_write_iter() - this also fixes the problem that at
btrfs_page_mkwrite() we were setting those fields without the
protection of the inode's spinlock.
This is an extremely unlikely race to happen in practice.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We need to be able to exclude page_mkwrite from happening concurrently
with certain operations. To facilitate this, add a i_mmap_lock to our
inode, down_read() it in our mkwrite, and add a new ILOCK flag to
indicate that we want to take the i_mmap_lock as well. I used pahole to
check the size of the btrfs_inode, the sizes are as follows
no lockdep:
before: 1120 (3 per 4k page)
after: 1160 (3 per 4k page)
lockdep:
before: 2072 (1 per 4k page)
after: 2224 (1 per 4k page)
We're slightly larger but it doesn't change how many objects we can fit
per page.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter mirror is not used and does not make sense for checksum
verification of the given bio.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
force_cow can be calculated from inode and does not need to be passed as
an argument.
This simplifies run_delalloc_nocow() call from btrfs_run_delalloc_range()
A new function, should_nocow() checks if the range should be NOCOWed or
not. The function returns true iff either BTRFS_INODE_NODATA or
BTRFS_INODE_PREALLOC, but is not a defrag extent.
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_extent_readonly() checks if the block group is readonly, the bool
return type should be used.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_extent_readonly() is used by can_nocow_extent() in inode.c. So
move it from extent-tree.c to inode.c and declare it as static.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the fileattr API to let the VFS handle locking, permission checking and
conversion.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Fixes for issues that have some user visibility and are simple enough
for this time of development cycle:
- a few fixes for rescue= mount option, adding more checks for
missing trees
- fix sleeping in atomic context on qgroup deletion
- fix subvolume deletion on mount
- fix build with M= syntax
- fix checksum mismatch error message for direct io"
* tag 'for-5.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix check_data_csum() error message for direct I/O
btrfs: fix sleep while in non-sleep context during qgroup removal
btrfs: fix subvolume/snapshot deletion not triggered on mount
btrfs: fix build when using M=fs/btrfs
btrfs: do not initialize dev replace for bad dev root
btrfs: initialize device::fs_info always
btrfs: do not initialize dev stats if we have no dev_root
btrfs: zoned: remove outdated WARN_ON in direct IO
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Merge tag 'for-5.12-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"There are still regressions being found and fixed in the zoned mode
and subpage code, the rest are fixes for bugs reported by users.
Regressions:
- subpage block support:
- readahead works on the proper block size
- fix last page zeroing
- zoned mode:
- linked list corruption for tree log
Fixes:
- qgroup leak after falloc failure
- tree mod log and backref resolving:
- extent buffer cloning race when resolving backrefs
- pin deleted leaves with active tree mod log users
- drop debugging flag from slab cache"
* tag 'for-5.12-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: always pin deleted leaves when there are active tree mod log users
btrfs: fix race when cloning extent buffer during rewind of an old root
btrfs: fix slab cache flags for free space tree bitmap
btrfs: subpage: make readahead work properly
btrfs: subpage: fix wild pointer access during metadata read failure
btrfs: zoned: fix linked list corruption after log root tree allocation failure
btrfs: fix qgroup data rsv leak caused by falloc failure
btrfs: track qgroup released data in own variable in insert_prealloc_file_extent
btrfs: fix wrong offset to zero out range beyond i_size
Commit 1dae796aabf6 ("btrfs: inode: sink parameter start and len to
check_data_csum()") replaced the start parameter to check_data_csum()
with page_offset(), but page_offset() is not meaningful for direct I/O
pages. Bring back the start parameter.
Fixes: 265d4ac03f ("btrfs: sink parameter start and len to check_data_csum")
CC: stable@vger.kernel.org # 5.11+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_submit_direct() there's a WAN_ON_ONCE() that will trigger if
we're submitting a DIO write on a zoned filesystem but are not using
REQ_OP_ZONE_APPEND to submit the IO to the block device.
This is a left over from a previous version where btrfs_dio_iomap_begin()
didn't use btrfs_use_zone_append() to check for sequential write only
zones.
It is an oversight from the development phase. In v11 (I think) I've
added 08f455593f ("btrfs: zoned: cache if block group is on a
sequential zone") and forgot to remove the WARN_ON_ONCE() for
544d24f9de ("btrfs: zoned: enable zone append writing for direct IO").
When developing auto relocation I got hit by the WARN as a block groups
where relocated to conventional zone and the dio code calls
btrfs_use_zone_append() introduced by 08f455593f to check if it can
use zone append (a.k.a. if it's a sequential zone) or not and sets the
appropriate flags for iomap.
I've never hit it in testing before, as I was relying on emulation to
test the conventional zones code but this one case wasn't hit, because
on emulation fs_info->max_zone_append_size is 0 and the WARN doesn't
trigger either.
Fixes: 544d24f9de ("btrfs: zoned: enable zone append writing for direct IO")
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The free space tree bitmap slab cache is created with SLAB_RED_ZONE but
that's a debugging flag and not always enabled. Also the other slabs are
created with at least SLAB_MEM_SPREAD that we want as well to average
the memory placement cost.
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 3acd48507d ("btrfs: fix allocation of free space cache v1 bitmap pages")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When running fsstress with only falloc workload, and a very low qgroup
limit set, we can get qgroup data rsv leak at unmount time.
BTRFS warning (device dm-0): qgroup 0/5 has unreleased space, type 0 rsv 20480
BTRFS error (device dm-0): qgroup reserved space leaked
The minimal reproducer looks like:
#!/bin/bash
dev=/dev/test/test
mnt="/mnt/btrfs"
fsstress=~/xfstests-dev/ltp/fsstress
runtime=8
workload()
{
umount $dev &> /dev/null
umount $mnt &> /dev/null
mkfs.btrfs -f $dev > /dev/null
mount $dev $mnt
btrfs quota en $mnt
btrfs quota rescan -w $mnt
btrfs qgroup limit 16m 0/5 $mnt
$fsstress -w -z -f creat=10 -f fallocate=10 -p 2 -n 100 \
-d $mnt -v > /tmp/fsstress
umount $mnt
if dmesg | grep leak ; then
echo "!!! FAILED !!!"
exit 1
fi
}
for (( i=0; i < $runtime; i++)); do
echo "=== $i/$runtime==="
workload
done
Normally it would fail before round 4.
[CAUSE]
In function insert_prealloc_file_extent(), we first call
btrfs_qgroup_release_data() to know how many bytes are reserved for
qgroup data rsv.
Then use that @qgroup_released number to continue our work.
But after we call btrfs_qgroup_release_data(), we should either queue
@qgroup_released to delayed ref or free them manually in error path.
Unfortunately, we lack the error handling to free the released bytes,
leaking qgroup data rsv.
All the error handling function outside won't help at all, as we have
released the range, meaning in inode io tree, the EXTENT_QGROUP_RESERVED
bit is already cleared, thus all btrfs_qgroup_free_data() call won't
free any data rsv.
[FIX]
Add free_qgroup tag to manually free the released qgroup data rsv.
Reported-by: Nikolay Borisov <nborisov@suse.com>
Reported-by: David Sterba <dsterba@suse.cz>
Fixes: 9729f10a60 ("btrfs: inode: move qgroup reserved space release to the callers of insert_reserved_file_extent()")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a piece of weird code in insert_prealloc_file_extent(), which
looks like:
ret = btrfs_qgroup_release_data(inode, file_offset, len);
if (ret < 0)
return ERR_PTR(ret);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
file_offset, &stack_fi,
true, ret);
...
}
extent_info.is_new_extent = true;
extent_info.qgroup_reserved = ret;
...
Note how the variable @ret is abused here, and if anyone is adding code
just after btrfs_qgroup_release_data() call, it's super easy to
overwrite the @ret and cause tons of qgroup related bugs.
Fix such abuse by introducing new variable @qgroup_released, so that we
won't reuse the existing variable @ret.
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-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"More regression fixes and stabilization.
Regressions:
- zoned mode
- count zone sizes in wider int types
- fix space accounting for read-only block groups
- subpage: fix page tail zeroing
Fixes:
- fix spurious warning when remounting with free space tree
- fix warning when creating a directory with smack enabled
- ioctl checks for qgroup inheritance when creating a snapshot
- qgroup
- fix missing unlock on error path in zero range
- fix amount of released reservation on error
- fix flushing from unsafe context with open transaction,
potentially deadlocking
- minor build warning fixes"
* tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: do not account freed region of read-only block group as zone_unusable
btrfs: zoned: use sector_t for zone sectors
btrfs: subpage: fix the false data csum mismatch error
btrfs: fix warning when creating a directory with smack enabled
btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
btrfs: export and rename qgroup_reserve_meta
btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata
btrfs: fix spurious free_space_tree remount warning
btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl
btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors
btrfs: ref-verify: use 'inline void' keyword ordering
Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:
* ae5e070eac ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")
* 6f23277a49 ("btrfs: qgroup: don't commit transaction when we already
hold the handle")
Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:
PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test"
#0 __schedule at ffffffffa529e07d
#1 schedule at ffffffffa529e4ff
#2 schedule_timeout at ffffffffa52a1bdd
#3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held
#4 start_delalloc_inodes at ffffffffc0380db5
#5 btrfs_start_delalloc_snapshot at ffffffffc0393836
#6 try_flush_qgroup at ffffffffc03f04b2
#7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes.
#8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex
#9 btrfs_update_inode at ffffffffc0385ba8
#10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED
#11 touch_atime at ffffffffa4cf0000
#12 generic_file_read_iter at ffffffffa4c1f123
#13 new_sync_read at ffffffffa4ccdc8a
#14 vfs_read at ffffffffa4cd0849
#15 ksys_read at ffffffffa4cd0bd1
#16 do_syscall_64 at ffffffffa4a052eb
#17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c
This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:
PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30"
#0 __schedule at ffffffffa529e07d
#1 schedule at ffffffffa529e4ff
#2 schedule_preempt_disabled at ffffffffa529e80a
#3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up.
#4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex
#5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding
#6 cow_file_range_inline.constprop.78 at ffffffffc0386be7
#7 cow_file_range at ffffffffc03879c1
#8 btrfs_run_delalloc_range at ffffffffc038894c
#9 writepage_delalloc at ffffffffc03a3c8f
#10 __extent_writepage at ffffffffc03a4c01
#11 extent_write_cache_pages at ffffffffc03a500b
#12 extent_writepages at ffffffffc03a6de2
#13 do_writepages at ffffffffa4c277eb
#14 __filemap_fdatawrite_range at ffffffffa4c1e5bb
#15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes
#16 normal_work_helper at ffffffffc03b706c
#17 process_one_work at ffffffffa4aba4e4
#18 worker_thread at ffffffffa4aba6fd
#19 kthread at ffffffffa4ac0a3d
#20 ret_from_fork at ffffffffa54001ff
To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.
Fixes: c53e965360 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"This is the first batch of fixes that usually arrive during the merge
window code freeze. Regressions and stable material.
Regressions:
- fix deadlock in log sync in zoned mode
- fix bugs in subpage mode still wrongly assuming sectorsize == page
size
Fixes:
- fix missing kunmap of the Q stripe in RAID6
- block group fixes:
- fix race between extent freeing/allocation when using bitmaps
- avoid double put of block group when emptying cluster
- swapfile fixes:
- fix swapfile writes vs running scrub
- fix swapfile activation vs snapshot creation
- fix stale data exposure after cloning a hole with NO_HOLES enabled
- remove tree-checker check that does not work in case information
from other leaves is necessary"
* tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: fix deadlock on log sync
btrfs: avoid double put of block group when emptying cluster
btrfs: fix stale data exposure after cloning a hole with NO_HOLES enabled
btrfs: tree-checker: do not error out if extent ref hash doesn't match
btrfs: fix race between swap file activation and snapshot creation
btrfs: fix race between writes to swap files and scrub
btrfs: avoid checking for RO block group twice during nocow writeback
btrfs: fix race between extent freeing/allocation when using bitmaps
btrfs: make check_compressed_csum() to be subpage compatible
btrfs: make btrfs_submit_compressed_read() subpage compatible
btrfs: fix raid6 qstripe kmap
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
When creating a snapshot we check if the current number of swap files, in
the root, is non-zero, and if it is, we error out and warn that we can not
create the snapshot because there are active swap files.
However this is racy because when a task started activation of a swap
file, another task might have started already snapshot creation and might
have seen the counter for the number of swap files as zero. This means
that after the swap file is activated we may end up with a snapshot of the
same root successfully created, and therefore when the first write to the
swap file happens it has to fall back into COW mode, which should never
happen for active swap files.
Basically what can happen is:
1) Task A starts snapshot creation and enters ioctl.c:create_snapshot().
There it sees that root->nr_swapfiles has a value of 0 so it continues;
2) Task B enters btrfs_swap_activate(). It is not aware that another task
started snapshot creation but it did not finish yet. It increments
root->nr_swapfiles from 0 to 1;
3) Task B checks that the file meets all requirements to be an active
swap file - it has NOCOW set, there are no snapshots for the inode's
root at the moment, no file holes, no reflinked extents, etc;
4) Task B returns success and now the file is an active swap file;
5) Task A commits the transaction to create the snapshot and finishes.
The swap file's extents are now shared between the original root and
the snapshot;
6) A write into an extent of the swap file is attempted - there is a
snapshot of the file's root, so we fall back to COW mode and therefore
the physical location of the extent changes on disk.
So fix this by taking the snapshot lock during swap file activation before
locking the extent range, as that is the order in which we lock these
during buffered writes.
Fixes: ed46ff3d42 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we active a swap file, at btrfs_swap_activate(), we acquire the
exclusive operation lock to prevent the physical location of the swap
file extents to be changed by operations such as balance and device
replace/resize/remove. We also call there can_nocow_extent() which,
among other things, checks if the block group of a swap file extent is
currently RO, and if it is we can not use the extent, since a write
into it would result in COWing the extent.
However we have no protection against a scrub operation running after we
activate the swap file, which can result in the swap file extents to be
COWed while the scrub is running and operating on the respective block
group, because scrub turns a block group into RO before it processes it
and then back again to RW mode after processing it. That means an attempt
to write into a swap file extent while scrub is processing the respective
block group, will result in COWing the extent, changing its physical
location on disk.
Fix this by making sure that block groups that have extents that are used
by active swap files can not be turned into RO mode, therefore making it
not possible for a scrub to turn them into RO mode. When a scrub finds a
block group that can not be turned to RO due to the existence of extents
used by swap files, it proceeds to the next block group and logs a warning
message that mentions the block group was skipped due to active swap
files - this is the same approach we currently use for balance.
Fixes: ed46ff3d42 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
During the nocow writeback path, we currently iterate the rbtree of block
groups twice: once for checking if the target block group is RO with the
call to btrfs_extent_readonly()), and once again for getting a nocow
reference on the block group with a call to btrfs_inc_nocow_writers().
Since btrfs_inc_nocow_writers() already returns false when the target
block group is RO, remove the call to btrfs_extent_readonly(). Not only
we avoid searching the blocks group rbtree twice, it also helps reduce
contention on the lock that protects it (specially since it is a spin
lock and not a read-write lock). That may make a noticeable difference
on very large filesystems, with thousands of allocated block groups.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When truncating a file, file buffers which have already been allocated
but not yet written may be truncated. Truncating these buffers could
cause breakage of a sequential write pattern in a block group if the
truncated blocks are for example followed by blocks allocated to another
file. To avoid this problem, always wait for write out of all unwritten
buffers before proceeding with the truncate execution.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If more than one IO is issued for one file extent, these IO can be
written to separate regions on a device. Since we cannot map one file
extent to such a separate area on a zoned filesystem, we need to follow
the "one IO == one ordered extent" rule.
The normal buffered, uncompressed and not pre-allocated write path (used
by cow_file_range()) sometimes does not follow this rule. It can write a
part of an ordered extent when specified a region to write e.g., when
its called from fdatasync().
Introduce a dedicated (uncompressed buffered) data write path for zoned
filesystems, that will COW the region and write it at once.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Likewise to buffered IO, enable zone append writing for direct IO when
its used on a zoned block device.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Enable zone append writing for zoned mode. When using zone append, a
bio is issued to the start of a target zone and the device decides to
place it inside the zone. Upon completion the device reports the actual
written position back to the host.
Three parts are necessary to enable zone append mode. First, modify the
bio to use REQ_OP_ZONE_APPEND in btrfs_submit_bio_hook() and adjust the
bi_sector to point the beginning of the zone.
Second, record the returned physical address (and disk/partno) to the
ordered extent in end_bio_extent_writepage() after the bio has been
completed. We cannot resolve the physical address to the logical address
because we can neither take locks nor allocate a buffer in this end_bio
context. So, we need to record the physical address to resolve it later
in btrfs_finish_ordered_io().
And finally, rewrite the logical addresses of the extent mapping and
checksum data according to the physical address using btrfs_rmap_block.
If the returned address matches the originally allocated address, we can
skip this rewriting process.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To ensure that an ordered extent maps to a contiguous region on disk, we
need to maintain a "one bio == one ordered extent" rule.
Ensure that constructing bio does not span more than an ordered extent.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For a zone append write, the device decides the location the data is being
written to. Therefore we cannot ensure that two bios are written
consecutively on the device. In order to ensure that an ordered extent
maps to a contiguous region on disk, we need to maintain a "one bio ==
one ordered extent" rule.
Implement splitting of an ordered extent and extent map on bio submission
to adhere to the rule.
extract_ordered_extent() hooks into btrfs_submit_data_bio() and splits the
corresponding ordered extent so that the ordered extent's region fits into
one bio and the corresponding device limits.
Several sanity checks need to be done in extract_ordered_extent() e.g.
- We cannot split once end_bio'd ordered extent because we cannot divide
ordered->bytes_left for the split ones
- We do not expect a compressed ordered extent
- We should not have checksum list because we omit the list splitting.
Since the function is called before btrfs_wq_submit_bio() or
btrfs_csum_one_bio(), this should be always ensured.
We also need to split an extent map by creating a new one. If not,
unpin_extent_cache() complains about the difference between the start of
the extent map and the file's logical offset.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Zoned filesystems use REQ_OP_ZONE_APPEND bios for writing to actual
devices.
Let btrfs_end_bio() and btrfs_op be aware of it, by mapping
REQ_OP_ZONE_APPEND to BTRFS_MAP_WRITE and using btrfs_op() instead of
bio_op().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To support subpage sector size, data also need extra info to make sure
which sectors in a page are uptodate/dirty/...
This patch will make pages for data inodes get btrfs_subpage structure
attached, and detached when the page is freed.
This patch also slightly changes the timing when
set_page_extent_mapped() is called to make sure:
- We have page->mapping set
page->mapping->host is used to grab btrfs_fs_info, thus we can only
call this function after page is mapped to an inode.
One call site attaches pages to inode manually, thus we have to modify
the timing of set_page_extent_mapped() a bit.
- As soon as possible, before other operations
Since memory allocation can fail, we have to do extra error handling.
Calling set_page_extent_mapped() as soon as possible can simply the
error handling for several call sites.
The idea is pretty much the same as iomap_page, but with more bitmaps
for btrfs specific cases.
Currently the plan is to switch iomap if iomap can provide sector
aligned write back (only write back dirty sectors, but not the full
page, data balance require this feature).
So we will stick to btrfs specific bitmap for now.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
PAGE_CLEAR_DIRTY and PAGE_SET_WRITEBACK are two defines used in
__process_pages_contig(), to let the function know to clear page dirty
bit and then set page writeback.
However page writeback and dirty bits are conflicting (at least for
sector size == PAGE_SIZE case), this means these two have to be always
updated together.
This means we can merge PAGE_CLEAR_DIRTY and PAGE_SET_WRITEBACK to
PAGE_START_WRITEBACK.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Before this change, the btrfs_get_io_geometry() function was calling
btrfs_get_chunk_map() to get the extent mapping, necessary for
calculating the I/O geometry. It was using that extent mapping only
internally and freeing the pointer after its execution.
That resulted in calling btrfs_get_chunk_map() de facto twice by the
__btrfs_map_block() function. It was calling btrfs_get_io_geometry()
first and then calling btrfs_get_chunk_map() directly to get the extent
mapping, used by the rest of the function.
Change that to passing the extent mapping to the btrfs_get_io_geometry()
function as an argument.
This could improve performance in some cases. For very large
filesystems, i.e. several thousands of allocated chunks, not only this
avoids searching two times the rbtree, saving time, it may also help
reducing contention on the lock that protects the tree - thinking of
writeback starting for multiple inodes, other tasks allocating or
removing chunks, and anything else that requires access to the rbtree.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Michal Rostecki <mrostecki@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add Filipe's analysis ]
Signed-off-by: David Sterba <dsterba@suse.com>
Commit dbfdb6d1b3 ("Btrfs: Search for all ordered extents that could
span across a page") make btrfs_invalidapage() to search all ordered
extents.
The offending code looks like this:
again:
start = page_start;
ordered = btrfs_lookup_ordered_range(inode, start, page_end - start + 1);
if (ordred) {
end = min(page_end,
ordered->file_offset + ordered->num_bytes - 1);
/* Do the cleanup */
start = end + 1;
if (start < page_end)
goto again;
}
The behavior is indeed necessary for the incoming subpage support, but
when it iterates through all the ordered extents, it also resets the
search range @start.
This means, for the following cases, we can double account the ordered
extents, causing its bytes_left underflow:
Page offset
0 16K 32K
|<--- OE 1 --->|<--- OE 2 ---->|
As the first iteration will find ordered extent (OE) 1, which doesn't
cover the full page, thus after cleanup code, we need to retry again.
But again label will reset start to page_start, and we got OE 1 again,
which causes double accounting on OE 1, and cause OE 1's byte_left to
underflow.
This problem can only happen for subpage case, as for regular sectorsize
== PAGE_SIZE case, we will always find a OE ends at or after page end,
thus no way to trigger the problem.
Move the again label after start = page_start. There will be more
comprehensive rework to convert the open coded loop to a proper while
loop for subpage support.
Fixes: dbfdb6d1b3 ("Btrfs: Search for all ordered extents that could span across a page")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The comment for can_nocow_extent() says that the function will flush
ordered extents, however that never happens and was never true before the
comment was added in commit e4ecaf90bc ("btrfs: add comments for
btrfs_check_can_nocow() and can_nocow_extent()"). This is true only for
the function btrfs_check_can_nocow(), which after that commit was renamed
to check_can_nocow(). So just remove that part of the comment.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Fixes fs/btrfs/inode.c:3101: warning: Function parameter or member 'fs_info' not described in 'btrfs_wait_on_delayed_iputs'
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
