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>
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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
...
In end_compressed_writeback() we just clear the full page writeback.
For subpage case, if there are two delalloc ranges in the same page, the
2nd range will trigger a BUG_ON() as the page writeback is already
cleared by previous range.
Fix it by using btrfs_page_clamp_clear_writeback() helper.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a WARN_ON() checking if @start is aligned to PAGE_SIZE, not
sectorsize, which will cause false alert for subpage. Fix it to check
against sectorsize.
Furthermore:
- Use ASSERT() to do the check
So that in the future we may skip the check for production build
- Also check alignment for @len
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_submit_compressed_write() will check
btrfs_bio_fits_in_stripe() each time a new page is going to be added.
Even if compressed extent is small, we don't really need to do that for
every page.
Align the behavior to extent_io.c, by determining the stripe boundary
when allocating a bio.
Unlike extent_io.c, in compressed.c we don't need to bother things like
different bio flags, thus no need to re-use bio_ctrl.
Here we just manually introduce new local variable, next_stripe_start,
and use that value returned from alloc_compressed_bio() to calculate
the stripe boundary.
Then each time we add some page range into the bio, we check if we
reached the boundary. And if reached, submit it.
Also, since we have @cur_disk_bytenr to determine whether we're the last
bio, we don't need a explicit last_bio: tag for error handling any more.
And since we use @cur_disk_bytenr to wait, there is no need for
pending_bios, also remove it to save some memory of compressed_bio.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_submit_compressed_read() will check
btrfs_bio_fits_in_stripe() each time a new page is going to be added.
Even if compressed extent is small, we don't really need to do that for
every page.
This patch will align the behavior to extent_io.c, by determining the
stripe boundary when allocating a bio.
Unlike extent_io.c, in compressed.c we don't need to bother things like
different bio flags, thus no need to re-use bio_ctrl.
Here we just manually introduce new local variable, next_stripe_start,
and teach alloc_compressed_bio() to calculate the stripe boundary.
Then each time we add some page range into the bio, we check if we
reached the boundary. And if reached, submit it.
Also, since we have @cur_disk_byte to determine whether we're the last
bio, we don't need a explicit last_bio: tag for error handling any more.
And we can use @cur_disk_byte to track which range has been added to
bio, we can also use @cur_disk_byte to calculate the wait condition, no
need for @pending_bios.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Just aggregate the bio allocation code into one helper, so that we can
replace 4 call sites.
There is one special note for zoned write.
Currently btrfs_submit_compressed_write() will only allocate the first
bio using ZONE_APPEND. If we have to submit current bio due to stripe
boundary, the new bio allocated will not use ZONE_APPEND.
In theory this should be a bug, but considering zoned mode currently
only support SINGLE profile, which doesn't have any stripe boundary
limit, it should never be a problem and we have assertions in place.
This function will provide a good entrance for any work which needs to
be done at bio allocation time. Like determining the stripe boundary.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The new helper, submit_compressed_bio(), will aggregate the following
work:
- Increase compressed_bio::pending_bios
- Remap the endio function
- Map and submit the bio
This slightly reorders calls to btrfs_csum_one_bio or
btrfs_lookup_bio_sums but but none of them does anything regarding IO
submission so this is effectively no change. We mainly care about order
of
- atomic_inc
- btrfs_bio_wq_end_io
- btrfs_map_bio
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Just like btrfs_submit_compressed_read(), there are quite some BUG_ON()s
inside btrfs_submit_compressed_write() for the bio submission path.
Fix them using the same method:
- For last bio, just endio the bio
As in that case, one of the endio function of all these submitted bio
will be able to free the compressed_bio
- For half-submitted bio, wait and finish the compressed_bio manually
In this case, as long as all other bio finish, we're the only one
referring the compressed bio, and can manually finish it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are quite some BUG_ON()s inside btrfs_submit_compressed_read(),
namely all errors inside the for() loop relies on BUG_ON() to handle
-ENOMEM.
Handle these errors properly by:
- Wait for submitted bios to finish first
Using wake_var_event() APIs to wait without introducing extra memory
overhead inside compressed_bio.
This allows us to wait for any submitted bio to finish, while still
keeps the compressed_bio from being freed.
- Introduce finish_compressed_bio_read() to finish the compressed_bio
- Properly end the bio and finish compressed_bio when error happens
Now in btrfs_submit_compressed_read() even when the bio submission
failed, we can properly handle the error without triggering BUG_ON().
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>
For btrfs_submit_compressed_read() and btrfs_submit_compressed_write(),
we have a pretty weird dance around compressed_bio::pending_bios:
btrfs_submit_compressed_read/write()
{
cb = kmalloc()
refcount_set(&cb->pending_bios, 0);
bio = btrfs_alloc_bio();
/* NOTE here, we haven't yet submitted any bio */
refcount_set(&cb->pending_bios, 1);
for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
if (submit) {
/* Here we submit bio, but we always have one
* extra pending_bios */
refcount_inc(&cb->pending_bios);
ret = btrfs_map_bio();
}
}
/* Submit the last bio */
ret = btrfs_map_bio();
}
There are two reasons why we do this:
- compressed_bio::pending_bios is a refcount
Thus if it's reduced to 0, it can not be increased again.
- To ensure the compressed_bio is not freed by some submitted bios
If the submitted bio is finished before the next bio submitted,
we can free the compressed_bio completely.
But the above code is sometimes confusing, and we can do it better by
introducing a new member, compressed_bio::pending_sectors.
Now we use compressed_bio::pending_sectors to indicate whether we have
any pending sectors under IO or not yet submitted.
If pending_sectors == 0, we're definitely the last bio of compressed_bio,
and is OK to release the compressed bio.
Now the workflow looks like this:
btrfs_submit_compressed_read/write()
{
cb = kmalloc()
atomic_set(&cb->pending_bios, 0);
refcount_set(&cb->pending_sectors,
compressed_len >> sectorsize_bits);
bio = btrfs_alloc_bio();
for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
if (submit) {
refcount_inc(&cb->pending_bios);
ret = btrfs_map_bio();
}
}
/* Submit the last bio */
refcount_inc(&cb->pending_bios);
ret = btrfs_map_bio();
}
For now we still need pending_bios for later error handling, but will
remove pending_bios eventually after properly handling the errors.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
If we remove the subpage limitation in add_ra_bio_pages(), then read a
compressed extent which has part of its range in next page, like the
following inode layout:
0 32K 64K 96K 128K
|<--------------|-------------->|
Btrfs will trigger ASSERT() in endio function:
assertion failed: atomic_read(&subpage->readers) >= nbits
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3431!
Internal error: Oops - BUG: 0 [#1] SMP
Workqueue: btrfs-endio btrfs_work_helper [btrfs]
Call trace:
assertfail.constprop.0+0x28/0x2c [btrfs]
btrfs_subpage_end_reader+0x148/0x14c [btrfs]
end_page_read+0x8c/0x100 [btrfs]
end_bio_extent_readpage+0x320/0x6b0 [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
---[ end trace c8b7b552d3bb408c ]---
[CAUSE]
When we read the page range [0, 64K), we find it's a compressed extent,
and we will try to add extra pages in add_ra_bio_pages() to avoid
reading the same compressed extent.
But when we add such page into the read bio, it doesn't follow the
behavior of btrfs_do_readpage() to properly set subpage::readers.
This means, for page [64K, 128K), its subpage::readers is still 0.
And when endio is executed on both pages, since page [64K, 128K) has 0
subpage::readers, it triggers above ASSERT()
[FIX]
Function add_ra_bio_pages() is far from subpage compatible, it always
assume PAGE_SIZE == sectorsize, thus when it skip to next range it
always just skip PAGE_SIZE.
Make it subpage compatible by:
- Skip to next page properly when needed
If we find there is already a page cache, we need to skip to next page.
For that case, we shouldn't just skip PAGE_SIZE bytes, but use
@pg_index to calculate the next bytenr and continue.
- Only add the page range covered by current extent map
We need to calculate which range is covered by current extent map and
only add that part into the read bio.
- Update subpage::readers before submitting the bio
- Use proper cursor other than confusing @last_offset
- Calculate the missed threshold based on sector size
It's no longer using missed pages, as for 64K page size, we have at
most 3 pages to skip. (If aligned only 2 pages)
- Add ASSERT() to make sure our bytenr is always aligned
- Add comment for the function
Add a special note for subpage case, as the function won't really
work well for subpage cases.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Variable @nr_pages only gets increased but never used. Remove it.
Signed-off-by: Qu Wenruo <wqu@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>
The helper btrfs_bio_alloc() is almost the same as btrfs_io_bio_alloc(),
except it's allocating using BIO_MAX_VECS as @nr_iovecs, and initializes
bio->bi_iter.bi_sector.
However the naming itself is not using "btrfs_io_bio" to indicate its
parameter is "strcut btrfs_io_bio" and can be easily confused with
"struct btrfs_bio".
Considering assigned bio->bi_iter.bi_sector is such a simple work and
there are already tons of call sites doing that manually, there is no
need to do that in a helper.
Remove btrfs_bio_alloc() helper, and enhance btrfs_io_bio_alloc()
function to provide a fail-safe value for its @nr_iovecs.
And then replace all btrfs_bio_alloc() callers with
btrfs_io_bio_alloc().
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 no need to pull blk-cgroup.h and thus blkdev.h in here, so
break the include chain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are several bugs inside the function btrfs_decompress_buf2page()
- @start_byte doesn't take bvec.bv_offset into consideration
Thus it can't handle case where the target range is not page aligned.
- Too many helper variables
There are tons of helper variables, @buf_offset, @current_buf_start,
@start_byte, @prev_start_byte, @working_bytes, @bytes.
This hurts anyone who wants to read the function.
- No obvious main cursor for the iteartion
A new problem caused by previous problem.
- Comments for parameter list makes no sense
Like @buf_start is the offset to @buf, or offset inside the full
decompressed extent? (Spoiler alert, the later case)
And @total_out acts more like @buf_start + @size_of_buf.
The worst is @disk_start.
The real meaning of it is the file offset of the full decompressed
extent.
This patch will rework the whole function by:
- Add a proper comment with ASCII art to explain the parameter list
- Rework parameter list
The old @buf_start is renamed to @decompressed, to show how many bytes
are already decompressed inside the full decompressed extent.
The old @total_out is replaced by @buf_len, which is the decompressed
data size.
For old @disk_start and @bio, just pass @compressed_bio in.
- Use single main cursor
The main cursor will be @cur_file_offset, to show what's the current
file offset.
Other helper variables will be declared inside the main loop, and only
minimal amount of helper variables:
* offset_inside_decompressed_buf: The only real helper
* copy_start_file_offset: File offset we start memcpy
* bvec_file_offset: File offset of current bvec
Even with all these extensive comments, the final function is still
smaller than the original function, which is definitely a win.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When subpage compressed read write support is enabled, btrfs/038 always
fails with EIO.
A simplified script can easily trigger the problem:
mkfs.btrfs -f -s 4k $dev
mount $dev $mnt -o compress=lzo
xfs_io -f -c "truncate 118811" $mnt/foo
xfs_io -c "pwrite -S 0x0d -b 39987 92267 39987" $mnt/foo > /dev/null
sync
btrfs subvolume snapshot -r $mnt $mnt/mysnap1
xfs_io -c "pwrite -S 0x3e -b 80000 200000 80000" $mnt/foo > /dev/null
sync
xfs_io -c "pwrite -S 0xdc -b 10000 250000 10000" $mnt/foo > /dev/null
xfs_io -c "pwrite -S 0xff -b 10000 300000 10000" $mnt/foo > /dev/null
sync
btrfs subvolume snapshot -r $mnt $mnt/mysnap2
cat $mnt/mysnap2/foo
# Above cat will fail due to EIO
[CAUSE]
The problem is in btrfs_submit_compressed_read().
When it tries to grab the extent map of the read range, it uses the
following call:
em = lookup_extent_mapping(em_tree,
page_offset(bio_first_page_all(bio)),
fs_info->sectorsize);
The problem is in the page_offset(bio_first_page_all(bio)) part.
The offending inode has the following file extent layout
item 10 key (257 EXTENT_DATA 131072) itemoff 15639 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 13680640 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0 (none)
item 11 key (257 EXTENT_DATA 135168) itemoff 15586 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 0 nr 0
item 12 key (257 EXTENT_DATA 196608) itemoff 15533 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 13676544 nr 4096
extent data offset 0 nr 53248 ram 86016
extent compression 2 (lzo)
And the bio passed in has the following parameters:
page_offset(bio_first_page_all(bio)) = 131072
bio_first_bvec_all(bio)->bv_offset = 65536
If we use page_offset(bio_first_page_all(bio) without adding bv_offset,
we will get an extent map for file offset 131072, not 196608.
This means we read uncompressed data from disk, and later decompression
will definitely fail.
[FIX]
Take bv_offset into consideration when trying to grab an extent map.
And add an ASSERT() to ensure we're really getting a compressed extent.
Thankfully this won't affect anything but subpage, thus we only need to
ensure this patch get merged before we enabled basic subpage support.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For current subpage support, we only support 64K page size with 4K
sector size.
This makes compressed readahead less effective, as maximum compressed
extent size is only 128K, 2x the page size.
On the other hand, the function add_ra_bio_pages() is still assuming
sectorsize == PAGE_SIZE, and code change may affect 4K page size
systems.
So for now, let's disable subpage compressed readahead for now.
Signed-off-by: Qu Wenruo <wqu@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>
The highmem flag is used for allocating pages for compression and for
raid56 pages. The high memory makes sense on 32bit systems but is not
without problems. On 64bit system's it's just another layer of wrappers.
The time the pages are allocated for compression or raid56 is relatively
short (about a transaction commit), so the pages are not blocked
indefinitely. As the number of pages depends on the amount of data being
written/read, there's a theoretical problem. A fast device on a 32bit
system could use most of the low memory pool, while with the highmem
allocation that would not happen. This was possibly the original idea
long time ago, but nowadays we optimize for 64bit systems.
This patch removes all usage of the __GFP_HIGHMEM flag for page
allocation, the kmap/kunmap are still in place and will be removed in
followup patches. Remaining is masking out the bit in
alloc_extent_state and __lookup_free_space_inode, that can safely stay.
Signed-off-by: David Sterba <dsterba@suse.com>
In compression write endio sequence, the range which the compressed_bio
writes is marked as uptodate if the last bio of the compressed (sub)bios
is completed successfully. There could be previous bio which may
have failed which is recorded in cb->errors.
Set the writeback range as uptodate only if cb->errors is zero, as opposed
to checking only the last bio's status.
Backporting notes: in all versions up to 4.4 the last argument is always
replaced by "!cb->errors".
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit 8140dc30a4 ("btrfs: btrfs_decompress_bio() could accept
compressed_bio instead"), btrfs_decompress_bio() accepts
"struct compressed_bio" other than open-coded parameter list.
Thus the comments for the parameter list is no longer needed.
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>
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>
Commit e5d7490236 ("btrfs: derive maximum output size in the
compression implementation") removed @max_out argument in
btrfs_compress_pages() but its comment remained, remove it.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Patch "btrfs: reduce compressed_bio member's types" reduced some
member's size. Function arguments @len, @compressed_len and @nr_pages
can be declared as unsigned int.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Patch "btrfs: reduce compressed_bio member's types" reduced some
member's size. Declare the variables @compressed_len, @nr_pages and
@pg_index size as an unsigned int in the function
btrfs_submit_compressed_read.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Several members of compressed_bio are of type that's unnecessarily big
for the values that they'd hold:
- the size of the uncompressed and compressed data is 128K now, we can
keep is as int
- same for number of pages
- the compress type fits to a byte
- the errors is 0/1
The size of the unpatched structure is 80 bytes with several holes.
Reordering nr_pages next to the pages the hole after pending_bios is
filled and the resulting size is 56 bytes. This keeps the csums array
aligned to 8 bytes, which is nice. Further size optimizations may be
possible but right now it looks good to me:
struct compressed_bio {
refcount_t pending_bios; /* 0 4 */
unsigned int nr_pages; /* 4 4 */
struct page * * compressed_pages; /* 8 8 */
struct inode * inode; /* 16 8 */
u64 start; /* 24 8 */
unsigned int len; /* 32 4 */
unsigned int compressed_len; /* 36 4 */
u8 compress_type; /* 40 1 */
u8 errors; /* 41 1 */
/* XXX 2 bytes hole, try to pack */
int mirror_num; /* 44 4 */
struct bio * orig_bio; /* 48 8 */
u8 sums[]; /* 56 0 */
/* size: 56, cachelines: 1, members: 12 */
/* sum members: 54, holes: 1, sum holes: 2 */
/* last cacheline: 56 bytes */
};
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To be able to construct a zone append bio we need to look up the
btrfs_device. The code doing the chunk map lookup to get the device is
present in btrfs_submit_compressed_write and submit_extent_page.
Factor out the lookup calls into a helper and use it in the submission
paths.
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-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
[BUG]
When running btrfs/027 with "-o compress" mount option, it always
crashes with the following call trace:
BTRFS critical (device dm-4): mapping failed logical 298901504 bio len 12288 len 8192
------------[ cut here ]------------
kernel BUG at fs/btrfs/volumes.c:6651!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 5 PID: 31089 Comm: kworker/u24:10 Tainted: G OE 5.13.0-rc2-custom+ #26
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
RIP: 0010:btrfs_map_bio.cold+0x58/0x5a [btrfs]
Call Trace:
btrfs_submit_compressed_write+0x2d7/0x470 [btrfs]
submit_compressed_extents+0x3b0/0x470 [btrfs]
? mark_held_locks+0x49/0x70
btrfs_work_helper+0x131/0x3e0 [btrfs]
process_one_work+0x28f/0x5d0
worker_thread+0x55/0x3c0
? process_one_work+0x5d0/0x5d0
kthread+0x141/0x160
? __kthread_bind_mask+0x60/0x60
ret_from_fork+0x22/0x30
---[ end trace 63113a3a91f34e68 ]---
[CAUSE]
The critical message before the crash means we have a bio at logical
bytenr 298901504 length 12288, but only 8192 bytes can fit into one
stripe, the remaining 4096 bytes go to another stripe.
In btrfs, all bios are properly split to avoid cross stripe boundary,
but commit 764c7c9a46 ("btrfs: zoned: fix parallel compressed writes")
changed the behavior for compressed writes.
Previously if we find our new page can't be fitted into current stripe,
ie. "submit == 1" case, we submit current bio without adding current
page.
submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio, 0);
page->mapping = NULL;
if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) <
PAGE_SIZE) {
But after the modification, we will add the page no matter if it crosses
stripe boundary, leading to the above crash.
submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio, 0);
if (pg_index == 0 && use_append)
len = bio_add_zone_append_page(bio, page, PAGE_SIZE, 0);
else
len = bio_add_page(bio, page, PAGE_SIZE, 0);
page->mapping = NULL;
if (submit || len < PAGE_SIZE) {
[FIX]
It's no longer possible to revert to the original code style as we have
two different bio_add_*_page() calls now.
The new fix is to skip the bio_add_*_page() call if @submit is true.
Also to avoid @len to be uninitialized, always initialize it to zero.
If @submit is true, @len will not be checked.
If @submit is not true, @len will be the return value of
bio_add_*_page() call.
Either way, the behavior is still the same as the old code.
Reported-by: Josef Bacik <josef@toxicpanda.com>
Fixes: 764c7c9a46 ("btrfs: zoned: fix parallel compressed writes")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When multiple processes write data to the same block group on a
compressed zoned filesystem, the underlying device could report I/O
errors and data corruption is possible.
This happens because on a zoned file system, compressed data writes
where sent to the device via a REQ_OP_WRITE instead of a
REQ_OP_ZONE_APPEND operation. But with REQ_OP_WRITE and parallel
submission it cannot be guaranteed that the data is always submitted
aligned to the underlying zone's write pointer.
The change to using REQ_OP_ZONE_APPEND instead of REQ_OP_WRITE on a
zoned filesystem is non intrusive on a regular file system or when
submitting to a conventional zone on a zoned filesystem, as it is
guarded by btrfs_use_zone_append.
Reported-by: David Sterba <dsterba@suse.com>
Fixes: 9d294a685f ("btrfs: zoned: enable to mount ZONED incompat flag")
CC: stable@vger.kernel.org # 5.12.x: e380adfc21: btrfs: zoned: pass start block to btrfs_use_zone_append
CC: stable@vger.kernel.org # 5.12.x
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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>
[BUG]
When running btrfs/071 with inode_need_compress() removed from
compress_file_range(), we got the following crash:
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
RIP: 0010:compress_file_range+0x476/0x7b0 [btrfs]
Call Trace:
? submit_compressed_extents+0x450/0x450 [btrfs]
async_cow_start+0x16/0x40 [btrfs]
btrfs_work_helper+0xf2/0x3e0 [btrfs]
process_one_work+0x278/0x5e0
worker_thread+0x55/0x400
? process_one_work+0x5e0/0x5e0
kthread+0x168/0x190
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x22/0x30
---[ end trace 65faf4eae941fa7d ]---
This is already after the patch "btrfs: inode: fix NULL pointer
dereference if inode doesn't need compression."
[CAUSE]
@pages is firstly created by kcalloc() in compress_file_extent():
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
Then passed to btrfs_compress_pages() to be utilized there:
ret = btrfs_compress_pages(...
pages,
&nr_pages,
...);
btrfs_compress_pages() will initialize each page as output, in
zlib_compress_pages() we have:
pages[nr_pages] = out_page;
nr_pages++;
Normally this is completely fine, but there is a special case which
is in btrfs_compress_pages() itself:
switch (type) {
default:
return -E2BIG;
}
In this case, we didn't modify @pages nor @out_pages, leaving them
untouched, then when we cleanup pages, the we can hit NULL pointer
dereference again:
if (pages) {
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
...
}
Since pages[i] are all initialized to zero, and btrfs_compress_pages()
doesn't change them at all, accessing pages[i]->mapping would lead to
NULL pointer dereference.
This is not possible for current kernel, as we check
inode_need_compress() before doing pages allocation.
But if we're going to remove that inode_need_compress() in
compress_file_extent(), then it's going to be a problem.
[FIX]
When btrfs_compress_pages() hits its default case, modify @out_pages to
0 to prevent such problem from happening.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212331
CC: stable@vger.kernel.org # 5.10+
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>
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>
Pull kmap conversion updates from David Sterba:
"This contains changes regarding kmap API use and eg conversion from
kmap_atomic to kmap_local_page.
The API belongs to memory management but to save cross-tree
dependency headaches we've agreed to take it through the btrfs tree
because there are some trivial conversions possible, while the rest
will need some time and getting the easy cases out of the way would be
convenient.
The changes can be grouped:
- function exports, new helpers
- new VM_BUG_ON for additional verification; it's been discussed if
it should be VM_BUG_ON or BUG_ON, the former was chosen due to
performance reasons
- code replaced by relevant helpers"
[ This is an updated version of a request that originally came in during
the merge window, but I asked for some updates:
https://lore.kernel.org/lkml/cover.1614090658.git.dsterba@suse.com/
which is why this got merge after the merge window closed. - Linus ]
* 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: use copy_highpage() instead of 2 kmaps()
btrfs: use memcpy_[to|from]_page() and kmap_local_page()
mm/highmem: Add VM_BUG_ON() to mem*_page() calls
mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page()
mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page()
mm/highmem: Lift memcpy_[to|from]_page to core
There are many places where the pattern kmap/memcpy/kunmap occurs.
This pattern was lifted to the core common functions
memcpy_[to|from]_page().
Use these new functions to reduce the code, eliminate direct uses of
kmap, and leverage the new core functions use of kmap_local_page().
Also, there is 1 place where a kmap/memcpy is followed by an
optional memset. Here we leave the kmap open coded to avoid remapping
the page but use kmap_local_page() directly.
Development of this patch was aided by the coccinelle script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap/memcpy/kunmap pattern and replace with memcpy*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:
//
// simple memcpy version
//
@ memcpy_rule1 @
expression page, T, F, B, Off;
identifier ptr;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
-memcpy(ptr + Off, F, B);
+memcpy_to_page(page, Off, F, B);
|
-memcpy(ptr, F, B);
+memcpy_to_page(page, 0, F, B);
|
-memcpy(T, ptr + Off, B);
+memcpy_from_page(T, page, Off, B);
|
-memcpy(T, ptr, B);
+memcpy_from_page(T, page, 0, B);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memcpy_rule1
@
identifier memcpy_rule1.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
//
// Some callers kmap without a temp pointer
//
@ memcpy_rule2 @
expression page, T, Off, F, B;
@@
<+...
(
-memcpy(kmap(page) + Off, F, B);
+memcpy_to_page(page, Off, F, B);
|
-memcpy(kmap(page), F, B);
+memcpy_to_page(page, 0, F, B);
|
-memcpy(T, kmap(page) + Off, B);
+memcpy_from_page(T, page, Off, B);
|
-memcpy(T, kmap(page), B);
+memcpy_from_page(T, page, 0, B);
)
...+>
-kunmap(page);
// No need for the ptr variable removal
//
// Catch all
//
@ memcpy_rule3 @
expression page;
expression GenTo, GenFrom, GenSize;
identifier ptr;
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 memcpy
// match a catch all to be evaluated by hand.
//
-memcpy(GenTo, GenFrom, GenSize);
+memcpy_to_pageExtra(page, GenTo, GenFrom, GenSize);
+memcpy_from_pageExtra(GenTo, page, GenFrom, GenSize);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memcpy_rule3
@
identifier memcpy_rule3.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
// <smpl>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently check_compressed_csum() completely relies on sectorsize ==
PAGE_SIZE to do checksum verification for compressed extents.
To make it subpage compatible, this patch will:
- Do extra calculation for the csum range
Since we have multiple sectors inside a page, we need to only hash
the range we want, not the full page anymore.
- Do sector-by-sector hash inside the page
With this patch and previous conversion on
btrfs_submit_compressed_read(), now we can read subpage compressed
extents properly, and do proper csum verification.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For compressed read, we always submit page read using page size. This
doesn't work well with subpage, as for subpage one page can contain
several sectors. Such submission will read range out of what we want,
and cause problems.
Thankfully to make it subpage compatible, we only need to change how the
last page of the compressed extent is read.
Instead of always adding a full page to the compressed read bio, if we're
at the last page, calculate the size using compressed length, so that we
only add part of the range into the compressed read bio.
Since we are here, also change the PAGE_SIZE used in
lookup_extent_mapping() to sectorsize.
This modification won't cause any functional change, as
lookup_extent_mapping() can handle the case where the search range is
larger than found extent range.
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>
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>
Refactor btrfs_lookup_bio_sums() by:
- Remove the @file_offset parameter
There are two factors making the @file_offset parameter useless:
* For csum lookup in csum tree, file offset makes no sense
We only need disk_bytenr, which is unrelated to file_offset
* page_offset (file offset) of each bvec is not contiguous.
Pages can be added to the same bio as long as their on-disk bytenr
is contiguous, meaning we could have pages at different file offsets
in the same bio.
Thus passing file_offset makes no sense any more.
The only user of file_offset is for data reloc inode, we will use
a new function, search_file_offset_in_bio(), to handle it.
- Extract the csum tree lookup into search_csum_tree()
The new function will handle the csum search in csum tree.
The return value is the same as btrfs_find_ordered_sum(), returning
the number of found sectors which have checksum.
- Change how we do the main loop
The only needed info from bio is:
* the on-disk bytenr
* the length
After extracting the above info, we can do the search without bio
at all, which makes the main loop much simpler:
for (cur_disk_bytenr = orig_disk_bytenr;
cur_disk_bytenr < orig_disk_bytenr + orig_len;
cur_disk_bytenr += count * sectorsize) {
/* Lookup csum tree */
count = search_csum_tree(fs_info, path, cur_disk_bytenr,
search_len, csum_dst);
if (!count) {
/* Csum hole handling */
}
}
- Use single variable as the source to calculate all other offsets
Instead of all different type of variables, we use only one main
variable, cur_disk_bytenr, which represents the current disk bytenr.
All involved values can be calculated from that variable, and
all those variable will only be visible in the inner loop.
The above refactoring makes btrfs_lookup_bio_sums() way more robust than
it used to be, especially related to the file offset lookup. Now
file_offset lookup is only related to data reloc inode, otherwise we
don't need to bother file_offset at all.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit 72deb455b5 ("block: remove CONFIG_LBDAF") (5.2) the
sector_t type is u64 on all arches and configs so we don't need to
typecast it. It used to be unsigned long and the result of sector size
shifts were not guaranteed to fit in the type.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove local variable that is then used just once and replace it with
fs_info::csum_size.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_info value is 32bit, switch also the local u16 variables. This
leads to a better assembly code generated due to movzwl.
This simple change will shave some bytes on x86_64 and release config:
text data bss dec hex filename
1090000 17980 14912 1122892 11224c pre/btrfs.ko
1089794 17980 14912 1122686 11217e post/btrfs.ko
DELTA: -206
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_get_16 shows up in the system performance profiles (helper to read
16bit values from on-disk structures). This is partially because of the
checksum size that's frequently read along with data reads/writes, other
u16 uses are from item size or directory entries.
Replace all calls to btrfs_super_csum_size by the cached value from
fs_info.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
