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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix freeing allocated id for anon dev when snapshot creation fails
- fiemap fixes:
- followup for a recent deadlock fix, ranges that fiemap can access
can still race with ordered extent completion
- make sure fiemap with SYNC flag does not race with writes
* tag 'for-6.8-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix double free of anonymous device after snapshot creation failure
btrfs: ensure fiemap doesn't race with writes when FIEMAP_FLAG_SYNC is given
btrfs: fix race between ordered extent completion and fiemap
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When FIEMAP_FLAG_SYNC is given to fiemap the expectation is that that
are no concurrent writes and we get a stable view of the inode's extent
layout.
When the flag is given we flush all IO (and wait for ordered extents to
complete) and then lock the inode in shared mode, however that leaves open
the possibility that a write might happen right after the flushing and
before locking the inode. So fix this by flushing again after locking the
inode - we leave the initial flushing before locking the inode to avoid
holding the lock and blocking other RO operations while waiting for IO
and ordered extents to complete. The second flushing while holding the
inode's lock will most of the time do nothing or very little since the
time window for new writes to have happened is small.
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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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few regular fixes and one fix for space reservation regression since
6.7 that users have been reporting:
- fix over-reservation of metadata chunks due to not keeping proper
balance between global block reserve and delayed refs reserve; in
practice this leaves behind empty metadata block groups, the
workaround is to reclaim them by using the '-musage=1' balance
filter
- other space reservation fixes:
- do not delete unused block group if it may be used soon
- do not reserve space for checksums for NOCOW files
- fix extent map assertion failure when writing out free space inode
- reject encoded write if inode has nodatasum flag set
- fix chunk map leak when loading block group zone info"
* tag 'for-6.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: don't refill whole delayed refs block reserve when starting transaction
btrfs: zoned: fix chunk map leak when loading block group zone info
btrfs: reject encoded write if inode has nodatasum flag set
btrfs: don't reserve space for checksums when writing to nocow files
btrfs: add new unused block groups to the list of unused block groups
btrfs: do not delete unused block group if it may be used soon
btrfs: add and use helper to check if block group is used
btrfs: don't drop extent_map for free space inode on write error
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Currently we allow an encoded write against inodes that have the NODATASUM
flag set, either because they are NOCOW files or they were created while
the filesystem was mounted with "-o nodatasum". This results in having
compressed extents without corresponding checksums, which is a filesystem
inconsistency reported by 'btrfs check'.
For example, running btrfs/281 with MOUNT_OPTIONS="-o nodatacow" triggers
this and 'btrfs check' errors out with:
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space tree
[4/7] checking fs roots
root 256 inode 257 errors 1040, bad file extent, some csum missing
root 256 inode 258 errors 1040, bad file extent, some csum missing
ERROR: errors found in fs roots
(...)
So reject encoded writes if the target inode has NODATASUM set.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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While running the CI for an unrelated change I hit the following panic
with generic/648 on btrfs_holes_spacecache.
assertion failed: block_start != EXTENT_MAP_HOLE, in fs/btrfs/extent_io.c:1385
------------[ cut here ]------------
kernel BUG at fs/btrfs/extent_io.c:1385!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 2695096 Comm: fsstress Kdump: loaded Tainted: G W 6.8.0-rc2+ #1
RIP: 0010:__extent_writepage_io.constprop.0+0x4c1/0x5c0
Call Trace:
<TASK>
extent_write_cache_pages+0x2ac/0x8f0
extent_writepages+0x87/0x110
do_writepages+0xd5/0x1f0
filemap_fdatawrite_wbc+0x63/0x90
__filemap_fdatawrite_range+0x5c/0x80
btrfs_fdatawrite_range+0x1f/0x50
btrfs_write_out_cache+0x507/0x560
btrfs_write_dirty_block_groups+0x32a/0x420
commit_cowonly_roots+0x21b/0x290
btrfs_commit_transaction+0x813/0x1360
btrfs_sync_file+0x51a/0x640
__x64_sys_fdatasync+0x52/0x90
do_syscall_64+0x9c/0x190
entry_SYSCALL_64_after_hwframe+0x6e/0x76
This happens because we fail to write out the free space cache in one
instance, come back around and attempt to write it again. However on
the second pass through we go to call btrfs_get_extent() on the inode to
get the extent mapping. Because this is a new block group, and with the
free space inode we always search the commit root to avoid deadlocking
with the tree, we find nothing and return a EXTENT_MAP_HOLE for the
requested range.
This happens because the first time we try to write the space cache out
we hit an error, and on an error we drop the extent mapping. This is
normal for normal files, but the free space cache inode is special. We
always expect the extent map to be correct. Thus the second time
through we end up with a bogus extent map.
Since we're deprecating this feature, the most straightforward way to
fix this is to simply skip dropping the extent map range for this failed
range.
I shortened the test by using error injection to stress the area to make
it easier to reproduce. With this patch in place we no longer panic
with my error injection test.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- zoned mode fixes:
- fix slowdown when writing large file sequentially by looking up
block groups with enough space faster
- locking fixes when activating a zone
- new mount API fixes:
- preserve mount options for a ro/rw mount of the same subvolume
- scrub fixes:
- fix use-after-free in case the chunk length is not aligned to
64K, this does not happen normally but has been reported on
images converted from ext4
- similar alignment check was missing with raid-stripe-tree
- subvolume deletion fixes:
- prevent calling ioctl on already deleted subvolume
- properly track flag tracking a deleted subvolume
- in subpage mode, fix decompression of an inline extent (zlib, lzo,
zstd)
- fix crash when starting writeback on a folio, after integration with
recent MM changes this needs to be started conditionally
- reject unknown flags in defrag ioctl
- error handling, API fixes, minor warning fixes
* tag 'for-6.8-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: scrub: limit RST scrub to chunk boundary
btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned
btrfs: don't unconditionally call folio_start_writeback in subpage
btrfs: use the original mount's mount options for the legacy reconfigure
btrfs: don't warn if discard range is not aligned to sector
btrfs: tree-checker: fix inline ref size in error messages
btrfs: zstd: fix and simplify the inline extent decompression
btrfs: lzo: fix and simplify the inline extent decompression
btrfs: zlib: fix and simplify the inline extent decompression
btrfs: defrag: reject unknown flags of btrfs_ioctl_defrag_range_args
btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted
btrfs: don't abort filesystem when attempting to snapshot deleted subvolume
btrfs: zoned: fix lock ordering in btrfs_zone_activate()
btrfs: fix unbalanced unlock of mapping_tree_lock
btrfs: ref-verify: free ref cache before clearing mount opt
btrfs: fix kvcalloc() arguments order in btrfs_ioctl_send()
btrfs: zoned: optimize hint byte for zoned allocator
btrfs: zoned: factor out prepare_allocation_zoned()
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being deleted
Sweet Tea spotted a race between subvolume deletion and snapshotting
that can result in the root item for the snapshot having the
BTRFS_ROOT_SUBVOL_DEAD flag set. The race is:
Thread 1 | Thread 2
----------------------------------------------|----------
btrfs_delete_subvolume |
btrfs_set_root_flags(BTRFS_ROOT_SUBVOL_DEAD)|
|btrfs_mksubvol
| down_read(subvol_sem)
| create_snapshot
| ...
| create_pending_snapshot
| copy root item from source
down_write(subvol_sem) |
This flag is only checked in send and swap activate, which this would
cause to fail mysteriously.
create_snapshot() now checks the root refs to reject a deleted
subvolume, so we can fix this by locking subvol_sem earlier so that the
BTRFS_ROOT_SUBVOL_DEAD flag and the root refs are updated atomically.
CC: stable@vger.kernel.org # 4.14+
Reported-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"There are no exciting changes for users, it's been mostly API
conversions and some fixes or refactoring.
The mount API conversion is a base for future improvements that would
come with VFS. Metadata processing has been converted to folios, not
yet enabling the large folios but it's one patch away once everything
gets tested enough.
Core changes:
- convert extent buffers to folios:
- direct API conversion where possible
- performance can drop by a few percent on metadata heavy
workloads, the folio sizes are not constant and the calculations
add up in the item helpers
- both regular and subpage modes
- data cannot be converted yet, we need to port that to iomap and
there are some other generic changes required
- convert mount to the new API, should not be user visible:
- options deprecated long time ago have been removed: inode_cache,
recovery
- the new logic that splits mount to two phases slightly changes
timing of device scanning for multi-device filesystems
- LSM options will now work (like for selinux)
- convert delayed nodes radix tree to xarray, preserving the
preload-like logic that still allows to allocate with GFP_NOFS
- more validation of sysfs value of scrub_speed_max
- refactor chunk map structure, reduce size and improve performance
- extent map refactoring, smaller data structures, improved
performance
- reduce size of struct extent_io_tree, embedded in several
structures
- temporary pages used for compression are cached and attached to a
shrinker, this may slightly improve performance
- in zoned mode, remove redirty extent buffer tracking, zeros are
written in case an out-of-order is detected and proper data are
written to the actual write pointer
- cleanups, refactoring, error message improvements, updated tests
- verify and update branch name or tag
- remove unwanted text"
* tag 'for-6.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (89 commits)
btrfs: pass btrfs_io_geometry into btrfs_max_io_len
btrfs: pass struct btrfs_io_geometry to set_io_stripe
btrfs: open code set_io_stripe for RAID56
btrfs: change block mapping to switch/case in btrfs_map_block
btrfs: factor out block mapping for single profiles
btrfs: factor out block mapping for RAID5/6
btrfs: reduce scope of data_stripes in btrfs_map_block
btrfs: factor out block mapping for RAID10
btrfs: factor out block mapping for DUP profiles
btrfs: factor out RAID1 block mapping
btrfs: factor out block-mapping for RAID0
btrfs: re-introduce struct btrfs_io_geometry
btrfs: factor out helper for single device IO check
btrfs: migrate btrfs_repair_io_failure() to folio interfaces
btrfs: migrate eb_bitmap_offset() to folio interfaces
btrfs: migrate various end io functions to folios
btrfs: migrate subpage code to folio interfaces
btrfs: migrate get_eb_page_index() and get_eb_offset_in_page() to folios
btrfs: don't double put our subpage reference in alloc_extent_buffer
btrfs: cleanup metadata page pointer usage
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
- Peng Zhang has done some mapletree maintainance work in the series
'maple_tree: add mt_free_one() and mt_attr() helpers'
'Some cleanups of maple tree'
- In the series 'mm: use memmap_on_memory semantics for dax/kmem'
Vishal Verma has altered the interworking between memory-hotplug
and dax/kmem so that newly added 'device memory' can more easily
have its memmap placed within that newly added memory.
- Matthew Wilcox continues folio-related work (including a few fixes)
in the patch series
'Add folio_zero_tail() and folio_fill_tail()'
'Make folio_start_writeback return void'
'Fix fault handler's handling of poisoned tail pages'
'Convert aops->error_remove_page to ->error_remove_folio'
'Finish two folio conversions'
'More swap folio conversions'
- Kefeng Wang has also contributed folio-related work in the series
'mm: cleanup and use more folio in page fault'
- Jim Cromie has improved the kmemleak reporting output in the series
'tweak kmemleak report format'.
- In the series 'stackdepot: allow evicting stack traces' Andrey
Konovalov to permits clients (in this case KASAN) to cause eviction
of no longer needed stack traces.
- Charan Teja Kalla has fixed some accounting issues in the page
allocator's atomic reserve calculations in the series 'mm:
page_alloc: fixes for high atomic reserve caluculations'.
- Dmitry Rokosov has added to the samples/ dorectory some sample code
for a userspace memcg event listener application. See the series
'samples: introduce cgroup events listeners'.
- Some mapletree maintanance work from Liam Howlett in the series
'maple_tree: iterator state changes'.
- Nhat Pham has improved zswap's approach to writeback in the series
'workload-specific and memory pressure-driven zswap writeback'.
- DAMON/DAMOS feature and maintenance work from SeongJae Park in the
series
'mm/damon: let users feed and tame/auto-tune DAMOS'
'selftests/damon: add Python-written DAMON functionality tests'
'mm/damon: misc updates for 6.8'
- Yosry Ahmed has improved memcg's stats flushing in the series 'mm:
memcg: subtree stats flushing and thresholds'.
- In the series 'Multi-size THP for anonymous memory' Ryan Roberts
has added a runtime opt-in feature to transparent hugepages which
improves performance by allocating larger chunks of memory during
anonymous page faults.
- Matthew Wilcox has also contributed some cleanup and maintenance
work against eh buffer_head code int he series 'More buffer_head
cleanups'.
- Suren Baghdasaryan has done work on Andrea Arcangeli's series
'userfaultfd move option'. UFFDIO_MOVE permits userspace heap
compaction algorithms to move userspace's pages around rather than
UFFDIO_COPY'a alloc/copy/free.
- Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm:
Add ksm advisor'. This is a governor which tunes KSM's scanning
aggressiveness in response to userspace's current needs.
- Chengming Zhou has optimized zswap's temporary working memory use
in the series 'mm/zswap: dstmem reuse optimizations and cleanups'.
- Matthew Wilcox has performed some maintenance work on the writeback
code, both code and within filesystems. The series is 'Clean up the
writeback paths'.
- Andrey Konovalov has optimized KASAN's handling of alloc and free
stack traces for secondary-level allocators, in the series 'kasan:
save mempool stack traces'.
- Andrey also performed some KASAN maintenance work in the series
'kasan: assorted clean-ups'.
- David Hildenbrand has gone to town on the rmap code. Cleanups, more
pte batching, folio conversions and more. See the series 'mm/rmap:
interface overhaul'.
- Kinsey Ho has contributed some maintenance work on the MGLRU code
in the series 'mm/mglru: Kconfig cleanup'.
- Matthew Wilcox has contributed lruvec page accounting code cleanups
in the series 'Remove some lruvec page accounting functions'"
* tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits)
mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER
mm, treewide: introduce NR_PAGE_ORDERS
selftests/mm: add separate UFFDIO_MOVE test for PMD splitting
selftests/mm: skip test if application doesn't has root privileges
selftests/mm: conform test to TAP format output
selftests: mm: hugepage-mmap: conform to TAP format output
selftests/mm: gup_test: conform test to TAP format output
mm/selftests: hugepage-mremap: conform test to TAP format output
mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING
mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large
mm/memcontrol: remove __mod_lruvec_page_state()
mm/khugepaged: use a folio more in collapse_file()
slub: use a folio in __kmalloc_large_node
slub: use folio APIs in free_large_kmalloc()
slub: use alloc_pages_node() in alloc_slab_page()
mm: remove inc/dec lruvec page state functions
mm: ratelimit stat flush from workingset shrinker
kasan: stop leaking stack trace handles
mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE
mm/mglru: add dummy pmd_dirty()
...
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Although subpage itself is conflicting with higher folio, since subpage
(sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE) means we will never
need higher order folio, there is a hidden pitfall:
- btrfs_page_*() helpers
Those helpers are an abstraction to handle both subpage and non-subpage
cases, which means we're going to pass pages pointers to those helpers.
And since those helpers are shared between data and metadata paths, it's
unavoidable to let them to handle folios, including higher order
folios).
Meanwhile for true subpage case, we should only have a single page
backed folios anyway, thus add a new ASSERT() for btrfs_subpage_assert()
to ensure that.
Also since those helpers are shared between both data and metadata, add
some extra ASSERT()s for data path to make sure we only get single page
backed folio for now.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Although we have migrated extent_buffer::pages[] to folios[], we're
still mostly using the folio_page() help to grab the page.
This patch would do the following cleanups for metadata:
- Introduce num_extent_folios() helper
This is to replace most num_extent_pages() callers.
- Use num_extent_folios() to iterate future large folios
This allows us to use things like
bio_add_folio()/bio_add_folio_nofail(), and only set the needed flags
for the folio (aka the leading/tailing page), which reduces the loop
iteration to 1 for large folios.
- Change metadata related functions to use folio pointers
Including their function name, involving:
* attach_extent_buffer_page()
* detach_extent_buffer_page()
* page_range_has_eb()
* btrfs_release_extent_buffer_pages()
* btree_clear_page_dirty()
* btrfs_page_inc_eb_refs()
* btrfs_page_dec_eb_refs()
- Change btrfs_is_subpage() to accept an address_space pointer
This is to allow both page->mapping and folio->mapping to be utilized.
As data is still using the old per-page code, and may keep so for a
while.
- Special corner case place holder for future order mismatches between
extent buffer and inode filemap
For now it's just a block of comments and a dead ASSERT(), no real
handling yet.
The subpage code would still go page, just because subpage and large
folio are conflicting conditions, thus we don't need to bother subpage
with higher order folios at all. Just folio_page(folio, 0) would be
enough.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor styling tweaks ]
Signed-off-by: David Sterba <dsterba@suse.com>
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Currently alloc_extent_buffer() utilizes find_or_create_page() to
allocate one page a time for an extent buffer.
This method has the following disadvantages:
- find_or_create_page() is the legacy way of allocating new pages
With the new folio infrastructure, find_or_create_page() is just
redirected to filemap_get_folio().
- Lacks the way to support higher order (order >= 1) folios
As we can not yet let filemap give us a higher order folio.
This patch would change the workflow by the following way:
Old | new
-----------------------------------+-------------------------------------
| ret = btrfs_alloc_page_array();
for (i = 0; i < num_pages; i++) { | for (i = 0; i < num_pages; i++) {
p = find_or_create_page(); | ret = filemap_add_folio();
/* Attach page private */ | /* Reuse page cache if needed */
/* Reused eb if needed */ |
| /* Attach page private and
| reuse eb if needed */
| }
By this we split the page allocation and private attaching into two
parts, allowing future updates to each part more easily, and migrate to
folio interfaces (especially for possible higher order folios).
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The radix-tree has been superseded by the xarray
(https://lwn.net/Articles/745073), this patch converts the
btrfs_root::delayed_nodes, the APIs are used in a simple way.
First idea is to do xa_insert() but this would require GFP_ATOMIC
allocation which we want to avoid if possible. The preload mechanism of
radix-tree can be emulated within the xarray API.
- xa_reserve() with GFP_NOFS outside of the lock, the reserved entry
is inserted atomically at most once
- xa_store() under a lock, in case something races in we can detect that
and xa_load() returns a valid pointer
All uses of xa_load() must check for a valid pointer in case they manage
to get between the xa_reserve() and xa_store(), this is handled in
btrfs_get_delayed_node().
Otherwise the functionality is equivalent, xarray implements the
radix-tree and there should be no performance difference.
The patch continues the efforts started in 253bf57555e451 ("btrfs: turn
delayed_nodes_tree into an XArray") and fixes the problems with locking
and GFP flags 088aea3b97e0ae ("Revert "btrfs: turn delayed_nodes_tree
into an XArray"").
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Currently, in struct extent_map, we use an unsigned int (32 bits) to
identify the compression type of an extent and an unsigned long (64 bits
on a 64 bits platform, 32 bits otherwise) for flags. We are only using
6 different flags, so an unsigned long is excessive and we can use flags
to identify the compression type instead of using a dedicated 32 bits
field.
We can easily have tens or hundreds of thousands (or more) of extent maps
on busy and large filesystems, specially with compression enabled or many
or large files with tons of small extents. So it's convenient to have the
extent_map structure as small as possible in order to use less memory.
So remove the compression type field from struct extent_map, use flags
to identify the compression type and shorten the flags field from an
unsigned long to a u32. This saves 8 bytes (on 64 bits platforms) and
reduces the size of the structure from 136 bytes down to 128 bytes, using
now only two cache lines, and increases the number of extent maps we can
have per 4K page from 30 to 32. By using a u32 for the flags instead of
an unsigned long, we no longer use test_bit(), set_bit() and clear_bit(),
but that level of atomicity is not needed as most flags are never cleared
once set (before adding an extent map to the tree), and the ones that can
be cleared or set after an extent map is added to the tree, are always
performed while holding the write lock on the extent map tree, while the
reader holds a lock on the tree or tests for a flag that never changes
once the extent map is in the tree (such as compression flags).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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At unpin_extent_range() we trigger a WARN_ON() when we don't find an
extent map or we find one with a start offset not matching the start
offset of the target range. This however isn't very useful for debugging
because:
1) We don't know which condition was triggered, as they are both in the
same WARN_ON() call;
2) We don't know which inode was affected, from which root, for which
range, what's the start offset of the extent map, and so on.
So trigger a separate warning for each case and log a message for each
case providing information about the inode, its root, the target range,
the generation and the start offset of the extent map we found.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The file_extent_tree was added in 41a2ee75aab0 ("btrfs: introduce
per-inode file extent tree") so we have an explicit mapping of the file
extents to know where it is safe to update i_size. When the feature
NO_HOLES is enabled, and it's been a mkfs default since 5.15, the tree
is not necessary.
To save some space in the inode, allocate the tree only when necessary.
This reduces size by 16 bytes from 1096 to 1080 on a x86_64 release
config.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When profiling a workload I noticed we were constantly calling getxattr.
These were mostly coming from __remove_privs, which will lookup if
security.capability exists to remove it. However instrumenting getxattr
showed we get called nearly constantly on an idle machine on a lot of
accesses.
These are wasteful and not free. Other security LSMs have a way to
cache their results, but capability doesn't have this, so it's asking us
all the time for the xattr.
Fix this by setting a flag in our inode that it doesn't have a
security.capability xattr. We set this on new inodes and after a failed
lookup of security.capability. If we set this xattr at all we'll clear
the flag.
I haven't found a test in fsperf that this makes a visible difference
on, but I assume fs_mark related tests would show it clearly. This is a
perf report output of the smallfiles100k run where it shows 20% of our
time spent in __remove_privs because we're looking up the non-existent
xattr.
--21.86%--btrfs_write_check.constprop.0
--21.62%--__file_remove_privs
--21.55%--security_inode_need_killpriv
--21.54%--cap_inode_need_killpriv
--21.53%--__vfs_getxattr
--20.89%--btrfs_getxattr
Obviously this is just CPU time in a mostly IO bound test, so the actual
effect of removing this callchain is minimal. However in just normal
testing of an idle system tracing showed around 100 getxattr calls per
minute, and with this patch there are 0.
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 extent_io_tree is embedded in several structures, notably in struct
btrfs_inode. The fs_info is only used for reporting errors and for
reference in trace points. We can get to the pointer through the inode,
but not all io trees set it. However, we always know the owner and
can recognize if inode is valid. For access helpers are provided, const
variant for the trace points.
This reduces size of extent_io_tree by 8 bytes and following structures
in turn:
- btrfs_inode 1104 -> 1088
- btrfs_device 520 -> 512
- btrfs_root 1360 -> 1344
- btrfs_transaction 456 -> 440
- btrfs_fs_info 3600 -> 3592
- reloc_control 1520 -> 1512
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The per-inode file extent tree was added in 41a2ee75aab0 ("btrfs:
introduce per-inode file extent tree"), it's the only tree type
that requires the lockdep class. Move it to the file where it is
actually used.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently we abuse the extent_map structure for two purposes:
1) To actually represent extents for inodes;
2) To represent chunk mappings.
This is odd and has several disadvantages:
1) To create a chunk map, we need to do two memory allocations: one for
an extent_map structure and another one for a map_lookup structure, so
more potential for an allocation failure and more complicated code to
manage and link two structures;
2) For a chunk map we actually only use 3 fields (24 bytes) of the
respective extent map structure: the 'start' field to have the logical
start address of the chunk, the 'len' field to have the chunk's size,
and the 'orig_block_len' field to contain the chunk's stripe size.
Besides wasting a memory, it's also odd and not intuitive at all to
have the stripe size in a field named 'orig_block_len'.
We are also using 'block_len' of the extent_map structure to contain
the chunk size, so we have 2 fields for the same value, 'len' and
'block_len', which is pointless;
3) When an extent map is associated to a chunk mapping, we set the bit
EXTENT_FLAG_FS_MAPPING on its flags and then make its member named
'map_lookup' point to the associated map_lookup structure. This means
that for an extent map associated to an inode extent, we are not using
this 'map_lookup' pointer, so wasting 8 bytes (on a 64 bits platform);
4) Extent maps associated to a chunk mapping are never merged or split so
it's pointless to use the existing extent map infrastructure.
So add a dedicated data structure named 'btrfs_chunk_map' to represent
chunk mappings, this is basically the existing map_lookup structure with
some extra fields:
1) 'start' to contain the chunk logical address;
2) 'chunk_len' to contain the chunk's length;
3) 'stripe_size' for the stripe size;
4) 'rb_node' for insertion into a rb tree;
5) 'refs' for reference counting.
This way we do a single memory allocation for chunk mappings and we don't
waste memory for them with unused/unnecessary fields from an extent_map.
We also save 8 bytes from the extent_map structure by removing the
'map_lookup' pointer, so the size of struct extent_map is reduced from
144 bytes down to 136 bytes, and we can now have 30 extents map per 4K
page instead of 28.
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>
|
|
As a cleanup and preparation for future folio migration, this patch
would replace all page->private to folio version. This includes:
- PagePrivate()
-> folio_test_private()
- page->private
-> folio_get_private()
- attach_page_private()
-> folio_attach_private()
- detach_page_private()
-> folio_detach_private()
Since we're here, also remove the forced cast on page->private, since
it's (void *) already, we don't really need to do the cast.
For now even if we missed some call sites, it won't cause any problem
yet, as we're only using order 0 folio (single page), thus all those
folio/page flags should be synced.
But for the future conversion to utilize higher order folio, the page
<-> folio flag sync is no longer guaranteed, thus we have to migrate to
utilize folio flags.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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 is a preparation for managing compression pages in a cache-like
manner, instead of asking the allocator each time. The common allocation
and free wrappers are introduced and are functionally equivalent to the
current code.
The freeing helpers need to be carefully placed where the last reference
is dropped. This is either after directly allocating (error handling)
or when there are no other users of the pages (after copying the contents).
It's safe to not use the helper and use put_page() that will handle the
reference count. Not using the helper means there's lower number of
pages that could be reused without passing them back to allocator.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Some fixes to quota accounting code, mostly around error handling and
correctness:
- free reserves on various error paths, after IO errors or
transaction abort
- don't clear reserved range at the folio release time, it'll be
properly cleared after final write
- fix integer overflow due to int used when passing around size of
freed reservations
- fix a regression in squota accounting that missed some cases with
delayed refs"
* tag 'for-6.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: ensure releasing squota reserve on head refs
btrfs: don't clear qgroup reserved bit in release_folio
btrfs: free qgroup pertrans reserve on transaction abort
btrfs: fix qgroup_free_reserved_data int overflow
btrfs: free qgroup reserve when ORDERED_IOERR is set
|
|
There were already assertions that we were not passing a tail page to
error_remove_page(), so make the compiler enforce that by converting
everything to pass and use a folio.
Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The reserved data counter and input parameter is a u64, but we
inadvertently accumulate it in an int. Overflowing that int results in
freeing the wrong amount of data and breaking reserve accounting.
Unfortunately, this overflow rot spreads from there, as the qgroup
release/free functions rely on returning an int to take advantage of
negative values for error codes.
Therefore, the full fix is to return the "released" or "freed" amount by
a u64 argument and to return 0 or negative error code via the return
value.
Most of the call sites simply ignore the return value, though some
of them handle the error and count the returned bytes. Change all of
them accordingly.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix potential overflow in returned value from SEARCH_TREE_V2
ioctl on 32bit architecture
- zoned mode fixes:
- drop unnecessary write pointer check for RAID0/RAID1/RAID10
profiles, now it works because of raid-stripe-tree
- wait for finishing the zone when direct IO needs a new
allocation
- simple quota fixes:
- pass correct owning root pointer when cleaning up an
aborted transaction
- fix leaking some structures when processing delayed refs
- change key type number of BTRFS_EXTENT_OWNER_REF_KEY,
reorder it before inline refs that are supposed to be
sorted, keeping the original number would complicate a lot
of things; this change needs an updated version of
btrfs-progs to work and filesystems need to be recreated
- fix error pointer dereference after failure to allocate fs
devices
- fix race between accounting qgroup extents and removing a
qgroup
* tag 'for-6.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: make OWNER_REF_KEY type value smallest among inline refs
btrfs: fix qgroup record leaks when using simple quotas
btrfs: fix race between accounting qgroup extents and removing a qgroup
btrfs: fix error pointer dereference after failure to allocate fs devices
btrfs: make found_logical_ret parameter mandatory for function queue_scrub_stripe()
btrfs: get correct owning_root when dropping snapshot
btrfs: zoned: wait for data BG to be finished on direct IO allocation
btrfs: zoned: drop no longer valid write pointer check
btrfs: directly return 0 on no error code in btrfs_insert_raid_extent()
btrfs: use u64 for buffer sizes in the tree search ioctls
|
|
Running the fio command below on a ZNS device results in "Resource
temporarily unavailable" error.
$ sudo fio --name=w --directory=/mnt --filesize=1GB --bs=16MB --numjobs=16 \
--rw=write --ioengine=libaio --iodepth=128 --direct=1
fio: io_u error on file /mnt/w.2.0: Resource temporarily unavailable: write offset=117440512, buflen=16777216
fio: io_u error on file /mnt/w.2.0: Resource temporarily unavailable: write offset=134217728, buflen=16777216
...
This happens because -EAGAIN error returned from btrfs_reserve_extent()
called from btrfs_new_extent_direct() is spilling over to the userland.
btrfs_reserve_extent() returns -EAGAIN when there is no active zone
available. Then, the caller should wait for some other on-going IO to
finish a zone and retry the allocation.
This logic is already implemented for buffered write in cow_file_range(),
but it is missing for the direct IO counterpart. Implement the same logic
for it.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 2ce543f47843 ("btrfs: zoned: wait until zone is finished when allocation didn't progress")
CC: stable@vger.kernel.org # 6.1+
Tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.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>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"New features:
- raid-stripe-tree
New tree for logical file extent mapping where the physical mapping
may not match on multiple devices. This is now used in zoned mode
to implement RAID0/RAID1* profiles, but can be used in non-zoned
mode as well. The support for RAID56 is in development and will
eventually fix the problems with the current implementation. This
is a backward incompatible feature and has to be enabled at mkfs
time.
- simple quota accounting (squota)
A simplified mode of qgroup that accounts all space on the initial
extent owners (a subvolume), the snapshots are then cheap to create
and delete. The deletion of snapshots in fully accounting qgroups
is a known CPU/IO performance bottleneck.
The squota is not suitable for the general use case but works well
for containers where the original subvolume exists for the whole
time. This is a backward incompatible feature as it needs extending
some structures, but can be enabled on an existing filesystem.
- temporary filesystem fsid (temp_fsid)
The fsid identifies a filesystem and is hard coded in the
structures, which disallows mounting the same fsid found on
different devices.
For a single device filesystem this is not strictly necessary, a
new temporary fsid can be generated on mount e.g. after a device is
cloned. This will be used by Steam Deck for root partition A/B
testing, or can be used for VM root images.
Other user visible changes:
- filesystems with partially finished metadata_uuid conversion cannot
be mounted anymore and the uuid fixup has to be done by btrfs-progs
(btrfstune).
Performance improvements:
- reduce reservations for checksum deletions (with enabled free space
tree by factor of 4), on a sample workload on file with many
extents the deletion time decreased by 12%
- make extent state merges more efficient during insertions, reduce
rb-tree iterations (run time of critical functions reduced by 5%)
Core changes:
- the integrity check functionality has been removed, this was a
debugging feature and removal does not affect other integrity
checks like checksums or tree-checker
- space reservation changes:
- more efficient delayed ref reservations, this avoids building up
too much work or overusing or exhausting the global block
reserve in some situations
- move delayed refs reservation to the transaction start time,
this prevents some ENOSPC corner cases related to exhaustion of
global reserve
- improvements in reducing excessive reservations for block group
items
- adjust overcommit logic in near full situations, account for one
more chunk to eventually allocate metadata chunk, this is mostly
relevant for small filesystems (<10GiB)
- single device filesystems are scanned but not registered (except
seed devices), this allows temp_fsid to work
- qgroup iterations do not need GFP_ATOMIC allocations anymore
- cleanups, refactoring, reduced data structure size, function
parameter simplifications, error handling fixes"
* tag 'for-6.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (156 commits)
btrfs: open code timespec64 in struct btrfs_inode
btrfs: remove redundant log root tree index assignment during log sync
btrfs: remove redundant initialization of variable dirty in btrfs_update_time()
btrfs: sysfs: show temp_fsid feature
btrfs: disable the device add feature for temp-fsid
btrfs: disable the seed feature for temp-fsid
btrfs: update comment for temp-fsid, fsid, and metadata_uuid
btrfs: remove pointless empty log context list check when syncing log
btrfs: update comment for struct btrfs_inode::lock
btrfs: remove pointless barrier from btrfs_sync_file()
btrfs: add and use helpers for reading and writing last_trans_committed
btrfs: add and use helpers for reading and writing fs_info->generation
btrfs: add and use helpers for reading and writing log_transid
btrfs: add and use helpers for reading and writing last_log_commit
btrfs: support cloned-device mount capability
btrfs: add helper function find_fsid_by_disk
btrfs: stop reserving excessive space for block group item insertions
btrfs: stop reserving excessive space for block group item updates
btrfs: reorder btrfs_inode to fill gaps
btrfs: open code btrfs_ordered_inode_tree in btrfs_inode
...
|
|
Convert to using the new inode timestamp accessor functions.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-21-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The type of timespec64::tv_nsec is 'unsigned long', while we have only
u32 for on-disk and in-memory. This wastes a few bytes in btrfs_inode.
Add separate members for sec and nsec with the corresponding type width.
This creates a 4 byte hole in btrfs_inode which can be utilized in the
future.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The variable dirty is initialized with a value that is never read, it
is being re-assigned later on. Remove the redundant initialization.
Cleans up clang scan build warning:
fs/btrfs/inode.c:5965:7: warning: Value stored to 'dirty' during its
initialization is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently the generation field of struct btrfs_fs_info is always modified
while holding fs_info->trans_lock locked. Most readers will access this
field without taking that lock but while holding a transaction handle,
which is safe to do due to the transaction life cycle.
However there are other readers that are neither holding the lock nor
holding a transaction handle open:
1) When reading an inode from disk, at btrfs_read_locked_inode();
2) When reading the generation to expose it to sysfs, at
btrfs_generation_show();
3) Early in the fsync path, at skip_inode_logging();
4) When creating a hole at btrfs_cont_expand(), during write paths,
truncate and reflinking;
5) In the fs_info ioctl (btrfs_ioctl_fs_info());
6) While mounting the filesystem, in the open_ctree() path. In these
cases it's safe to directly read fs_info->generation as no one
can concurrently start a transaction and update fs_info->generation.
In case of the fsync path, races here should be harmless, and in the worst
case they may cause a fsync to log an inode when it's not really needed,
so nothing bad from a functional perspective. In the other cases it's not
so clear if functional problems may arise, though in case 1 rare things
like a load/store tearing [1] may cause the BTRFS_INODE_NEEDS_FULL_SYNC
flag not being set on an inode and therefore result in incorrect logging
later on in case a fsync call is made.
To avoid data race warnings from tools like KCSAN and other issues such
as load and store tearing (amongst others, see [1]), create helpers to
access the generation field of struct btrfs_fs_info using READ_ONCE() and
WRITE_ONCE(), and use these helpers where needed.
[1] https://lwn.net/Articles/793253/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The structure btrfs_ordered_inode_tree is used only in one place, in
btrfs_inode. The structure itself has a 4 byte hole which is wasted
space.
Move the btrfs_ordered_inode_tree members to btrfs_inode with a common
prefix 'ordered_tree_' where the hole can be utilized and shrink inode
size.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The semantics of test_range_bit() with filled == 0 is now in it's own
helper so test_range_bit will check the whole range unconditionally.
The detection logic is flipped and assumes success by default and
catches exceptions.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The existing helper test_range_bit works in two ways, checks if the whole
range contains all the bits, or stop on the first occurrence. By adding
a specific helper for the latter case, the inner loop can be simplified
and contains fewer conditionals, making it a bit faster.
There's no caller that uses the cached state pointer so this reduces the
argument count further.
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The root argument for maybe_insert_hole() always matches the root of the
given inode, so remove the root argument and get it from the inode
argument.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The root argument for btrfs_delayed_update_inode() always matches the root
of the given inode, so remove the root argument and get it from the inode
argument.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The root argument for btrfs_update_inode_item() always matches the root of
the given inode, so remove the root argument and get it from the inode
argument.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The root argument for btrfs_update_inode() always matches the root of the
given inode, so remove the root argument and get it from the inode
argument.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The root argument for btrfs_update_inode_fallback() always matches the
root of the given inode, so remove the root argument and get it from the
inode argument.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The noinline attribute of btrfs_update_inode() is pointless as the
function is exported and widely used, so remove it.
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>
|
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The following condition at btrfs_dirty_inode() is redundant:
if (ret && (ret == -ENOSPC || ret == -EDQUOT))
The first check for a non-zero 'ret' value is pointless, we can simplify
this to simply:
if (ret == -ENOSPC || ret == -EDQUOT)
Not only this makes it easier to read, it also slightly reduces the text
size of the btrfs kernel module:
$ size fs/btrfs/btrfs.ko.before
text data bss dec hex filename
1641400 168265 16864 1826529 1bdee1 fs/btrfs/btrfs.ko.before
$ size fs/btrfs/btrfs.ko.after
text data bss dec hex filename
1641224 168181 16864 1826269 1bdddd fs/btrfs/btrfs.ko.after
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There are two callbacks defined in btrfs_work but only two actually make
use of them, otherwise there are NULLs. We can get rid of the freeing
callback making it a special case of the normal work. This reduces the
size of btrfs_work by 8 bytes, final layout:
struct btrfs_work {
btrfs_func_t func; /* 0 8 */
btrfs_ordered_func_t ordered_func; /* 8 8 */
struct work_struct normal_work; /* 16 32 */
struct list_head ordered_list; /* 48 16 */
/* --- cacheline 1 boundary (64 bytes) --- */
struct btrfs_workqueue * wq; /* 64 8 */
long unsigned int flags; /* 72 8 */
/* size: 80, cachelines: 2, members: 6 */
/* last cacheline: 16 bytes */
};
This in turn reduces size of other structures (on a release config):
- async_chunk 160 -> 152
- async_submit_bio 152 -> 144
- btrfs_async_delayed_work 104 -> 96
- btrfs_caching_control 176 -> 168
- btrfs_delalloc_work 144 -> 136
- btrfs_fs_info 3608 -> 3600
- btrfs_ordered_extent 440 -> 424
- btrfs_writepage_fixup 104 -> 96
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Add support for inserting stripe extents into the raid stripe tree on
completion of every write that needs an extra logical-to-physical
translation when using RAID.
Inserting the stripe extents happens after the data I/O has completed,
this is done to
a) support zone-append and
b) rule out the possibility of a RAID-write-hole.
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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When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(),
we check if its generation matches the running transaction and if not we
just print a warning. Such mismatch is an indicator that something really
went wrong and only printing a warning message (and stack trace) is not
enough to prevent a corruption. Allowing a transaction to commit with such
an extent buffer will trigger an error if we ever try to read it from disk
due to a generation mismatch with its parent generation.
So abort the current transaction with -EUCLEAN if we notice a generation
mismatch. For this we need to pass a transaction handle to
btrfs_mark_buffer_dirty() which is always available except in test code,
in which case we can pass NULL since it operates on dummy extent buffers
and all test roots have a single node/leaf (root node at level 0).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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Function name in the comment does not bring much value to code not
exposed as API and we don't stick to the kdoc format anymore. Update
formatting of parameter descriptions.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more followup fixes to the directory listing.
People have noticed different behaviour compared to other filesystems
after changes in 6.5. This is now unified to more "logical" and
expected behaviour while still within POSIX. And a few more fixes for
stable.
- change behaviour of readdir()/rewinddir() when new directory
entries are created after opendir(), properly tracking the last
entry
- fix race in readdir when multiple threads can set the last entry
index for a directory
Additionally:
- use exclusive lock when direct io might need to drop privs and call
notify_change()
- don't clear uptodate bit on page after an error, this may lead to a
deadlock in subpage mode
- fix waiting pattern when multiple readers block on Merkle tree
data, switch to folios"
* tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix race between reading a directory and adding entries to it
btrfs: refresh dir last index during a rewinddir(3) call
btrfs: set last dir index to the current last index when opening dir
btrfs: don't clear uptodate on write errors
btrfs: file_remove_privs needs an exclusive lock in direct io write
btrfs: convert btrfs_read_merkle_tree_page() to use a folio
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When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:
Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc
The race leading to the problem happens like this:
1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());
2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.
Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...
3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...
4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;
5) Task B assigns 101 to the index_cnt field of inode X;
6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.
Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.
Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When opening a directory we find what's the index of its last entry and
then store it in the directory's file handle private data (struct
btrfs_file_private::last_index), so that in the case new directory entries
are added to a directory after an opendir(3) call we don't end up in an
infinite loop (see commit 9b378f6ad48c ("btrfs: fix infinite directory
reads")) when calling readdir(3).
However once rewinddir(3) is called, POSIX states [1] that any new
directory entries added after the previous opendir(3) call, must be
returned by subsequent calls to readdir(3):
"The rewinddir() function shall reset the position of the directory
stream to which dirp refers to the beginning of the directory.
It shall also cause the directory stream to refer to the current
state of the corresponding directory, as a call to opendir() would
have done."
We currently don't refresh the last_index field of the struct
btrfs_file_private associated to the directory, so after a rewinddir(3)
we are not returning any new entries added after the opendir(3) call.
Fix this by finding the current last index of the directory when llseek
is called against the directory.
This can be reproduced by the following C program provided by Ian Johnson:
#include <dirent.h>
#include <stdio.h>
int main(void) {
DIR *dir = opendir("test");
FILE *file;
file = fopen("test/1", "w");
fwrite("1", 1, 1, file);
fclose(file);
file = fopen("test/2", "w");
fwrite("2", 1, 1, file);
fclose(file);
rewinddir(dir);
struct dirent *entry;
while ((entry = readdir(dir))) {
printf("%s\n", entry->d_name);
}
closedir(dir);
return 0;
}
Reported-by: Ian Johnson <ian@ianjohnson.dev>
Link: https://lore.kernel.org/linux-btrfs/YR1P0S.NGASEG570GJ8@ianjohnson.dev/
Fixes: 9b378f6ad48c ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When opening a directory for reading it, we set the last index where we
stop iteration to the value in struct btrfs_inode::index_cnt. That value
does not match the index of the most recently added directory entry but
it's instead the index number that will be assigned the next directory
entry.
This means that if after the call to opendir(3) new directory entries are
added, a readdir(3) call will return the first new directory entry. This
is fine because POSIX says the following [1]:
"If a file is removed from or added to the directory after the most
recent call to opendir() or rewinddir(), whether a subsequent call to
readdir() returns an entry for that file is unspecified."
For example for the test script from commit 9b378f6ad48c ("btrfs: fix
infinite directory reads"), where we have 2000 files in a directory, ext4
doesn't return any new directory entry after opendir(3), while xfs returns
the first 13 new directory entries added after the opendir(3) call.
If we move to a shorter example with an empty directory when opendir(3) is
called, and 2 files added to the directory after the opendir(3) call, then
readdir(3) on btrfs will return the first file, ext4 and xfs return the 2
files (but in a different order). A test program for this, reported by
Ian Johnson, is the following:
#include <dirent.h>
#include <stdio.h>
int main(void) {
DIR *dir = opendir("test");
FILE *file;
file = fopen("test/1", "w");
fwrite("1", 1, 1, file);
fclose(file);
file = fopen("test/2", "w");
fwrite("2", 1, 1, file);
fclose(file);
struct dirent *entry;
while ((entry = readdir(dir))) {
printf("%s\n", entry->d_name);
}
closedir(dir);
return 0;
}
To make this less odd, change the behaviour to never return new entries
that were added after the opendir(3) call. This is done by setting the
last_index field of the struct btrfs_file_private attached to the
directory's file handle with a value matching btrfs_inode::index_cnt
minus 1, since that value always matches the index of the next new
directory entry and not the index of the most recently added entry.
[1] https://pubs.opengroup.org/onlinepubs/007904875/functions/readdir_r.html
Link: https://lore.kernel.org/linux-btrfs/YR1P0S.NGASEG570GJ8@ianjohnson.dev/
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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