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2022-11-09xfs: add debug knob to slow down write for funiomap-write-races-6.2_2022-11-09Darrick J. Wong
Add a new error injection knob so that we can arbitrarily slow down pagecahe writes to test for race conditions and aberrant reclaim behavior if the writeback mechanisms are slow to issue writeback. This will enable functional testing for the ifork sequence counters introduced in commit XXXXXXXXXXXX that fixes write racing with reclaim writeback. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: add debug knob to slow down writeback for funDarrick J. Wong
Add a new error injection knob so that we can arbitrarily slow down writeback to test for race conditions and aberrant reclaim behavior if the writeback mechanisms are slow to issue writeback. This will enable functional testing for the ifork sequence counters introduced in commit 745b3f76d1c8 ("xfs: maintain a sequence count for inode fork manipulations"). Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: validate COW fork sequence counters during buffered writesDarrick J. Wong
In the previous patch, we transformed the iomap revalidation code to use an explicit context object where data and cow fork sequence counters are tracked explicitly. The existing validation function only validated the data fork sequence counter, so now let's make it validate both. I /think/ this isn't actually necessary here because we're writing to the page cache, and the page state does not track or care about cow status. However, this question came up when Dave and I were chatting about this patchset on IRC, so here it is for formal consideration. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: move the seq counters for buffered writes to a private structDarrick J. Wong
To avoid racing with writeback, XFS needs to revalidate (io)mappings after grabbing each folio lock. Right now, XFS stashes the sequence counter values in the (void *pointer) field of the iomap, which is not the greatest solution. First, we don't record which fork was sampled, which means that the current code which samples either fork and compares it to the data fork seqcount is wrong. Second, if another thread touches the cow fork, we (conservatively) want to revalidate because *something* has changed. The previous three patches reorganized the iomap callbacks to pass the iomap_iter to the ->iomap_{begin,end} functions and provided a way to set the iter->private field for a buffered write. Now we can update the buffered write paths in XFS to allocate the necessary memory to sample both forks' sequence counters and revalidate the data fork during a write operation. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09iomap: pass a private pointer to iomap_file_buffered_writeDarrick J. Wong
Allow filesystems to pass a filesystem-private pointer into iomap for writes into the pagecache. This will now be accessible from ->iomap_begin implementations, which is key to being able to revalidate mappings after taking folio locks. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09iomap: pass iter to ->iomap_end implementationsDarrick J. Wong
Clean up the ->iomap_end call sites by passing a pointer to the iter structure into the iomap_end functions. This isn't strictly needed, but it cleans up the callsites neatly. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09iomap: pass iter to ->iomap_begin implementationsDarrick J. Wong
Clean up the ->iomap_begin call sites by passing a pointer to the iter structure into the iomap_begin functions. This will be needed to clean up the xfs race condition fixes in the next patch, and will hopefully reduce register pressure as well. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: drop write error injection is unfixable, remove itDave Chinner
With the changes to scan the page cache for dirty data to avoid data corruptions from partial write cleanup racing with other page cache operations, the drop writes error injection no longer works the same way it used to and causes xfs/196 to fail. This is because xfs/196 writes to the file and populates the page cache before it turns on the error injection and starts failing -overwrites-. The result is that the original drop-writes code failed writes only -after- overwriting the data in the cache, followed by invalidates the cached data, then punching out the delalloc extent from under that data. On the surface, this looks fine. The problem is that page cache invalidation *doesn't guarantee that it removes anything from the page cache* and it doesn't change the dirty state of the folio. When block size == page size and we do page aligned IO (as xfs/196 does) everything happens to align perfectly and page cache invalidation removes the single page folios that span the written data. Hence the followup delalloc punch pass does not find cached data over that range and it can punch the extent out. IOWs, xfs/196 "works" for block size == page size with the new code. I say "works", because it actually only works for the case where IO is page aligned, and no data was read from disk before writes occur. Because the moment we actually read data first, the readahead code allocates multipage folios and suddenly the invalidate code goes back to zeroing subfolio ranges without changing dirty state. Hence, with multipage folios in play, block size == page size is functionally identical to block size < page size behaviour, and drop-writes is manifestly broken w.r.t to this case. Invalidation of a subfolio range doesn't result in the folio being removed from the cache, just the range gets zeroed. Hence after we've sequentially walked over a folio that we've dirtied (via write data) and then invalidated, we end up with a dirty folio full of zeroed data. And because the new code skips punching ranges that have dirty folios covering them, we end up leaving the delalloc range intact after failing all the writes. Hence failed writes now end up writing zeroes to disk in the cases where invalidation zeroes folios rather than removing them from cache. This is a fundamental change of behaviour that is needed to avoid the data corruption vectors that exist in the old write fail path, and it renders the drop-writes injection non-functional and unworkable as it stands. As it is, I think the error injection is also now unnecessary, as partial writes that need delalloc extent are going to be a lot more common with stale iomap detection in place. Hence this patch removes the drop-writes error injection completely. xfs/196 can remain for testing kernels that don't have this data corruption fix, but those that do will report: xfs/196 3s ... [not run] XFS error injection drop_writes unknown on this kernel. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: use iomap_valid method to detect stale cached iomapsDave Chinner
Now that iomap supports a mechanism to validate cached iomaps for buffered write operations, hook it up to the XFS buffered write ops so that we can avoid data corruptions that result from stale cached iomaps. See: https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/ or the ->iomap_valid() introduction commit for exact details of the corruption vector. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09iomap: write iomap validity checksDave Chinner
A recent multithreaded write data corruption has been uncovered in the iomap write code. The core of the problem is partial folio writes can be flushed to disk while a new racing write can map it and fill the rest of the page: writeback new write allocate blocks blocks are unwritten submit IO ..... map blocks iomap indicates UNWRITTEN range loop { lock folio copyin data ..... IO completes runs unwritten extent conv blocks are marked written <iomap now stale> get next folio } Now add memory pressure such that memory reclaim evicts the partially written folio that has already been written to disk. When the new write finally gets to the last partial page of the new write, it does not find it in cache, so it instantiates a new page, sees the iomap is unwritten, and zeros the part of the page that it does not have data from. This overwrites the data on disk that was originally written. The full description of the corruption mechanism can be found here: https://lore.kernel.org/linux-xfs/20220817093627.GZ3600936@dread.disaster.area/ To solve this problem, we need to check whether the iomap is still valid after we lock each folio during the write. We have to do it after we lock the page so that we don't end up with state changes occurring while we wait for the folio to be locked. Hence we need a mechanism to be able to check that the cached iomap is still valid (similar to what we already do in buffered writeback), and we need a way for ->begin_write to back out and tell the high level iomap iterator that we need to remap the remaining write range. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: buffered write failure should not truncate the page cacheDave Chinner
xfs_buffered_write_iomap_end() currently invalidates the page cache over the unused range of the delalloc extent it allocated. While the write allocated the delalloc extent, it does not own it exclusively as the write does not hold any locks that prevent either writeback or mmap page faults from changing the state of either the page cache or the extent state backing this range. Whilst xfs_bmap_punch_delalloc_range() already handles races in extent conversion - it will only punch out delalloc extents and it ignores any other type of extent - the page cache truncate does not discriminate between data written by this write or some other task. As a result, truncating the page cache can result in data corruption if the write races with mmap modifications to the file over the same range. generic/346 exercises this workload, and if we randomly fail writes (as will happen when iomap gets stale iomap detection later in the patchset), it will randomly corrupt the file data because it removes data written by mmap() in the same page as the write() that failed. Hence we do not want to punch out the page cache over the range of the extent we failed to write to - what we actually need to do is detect the ranges that have dirty data in cache over them and *not punch them out*. TO do this, we have to walk the page cache over the range of the delalloc extent we want to remove. This is made complex by the fact we have to handle partially up-to-date folios correctly and this can happen even when the FSB size == PAGE_SIZE because we now support multi-page folios in the page cache. Because we are only interested in discovering the edges of data ranges in the page cache (i.e. hole-data boundaries) we can make use of mapping_seek_hole_data() to find those transitions in the page cache. As we hold the invalidate_lock, we know that the boundaries are not going to change while we walk the range. This interface is also byte-based and is sub-page block aware, so we can find the data ranges in the cache based on byte offsets rather than page, folio or fs block sized chunks. This greatly simplifies the logic of finding dirty cached ranges in the page cache. Once we've identified a range that contains cached data, we can then iterate the range folio by folio. This allows us to determine if the data is dirty and hence perform the correct delalloc extent punching operations. The seek interface we use to iterate data ranges will give us sub-folio start/end granularity, so we may end up looking up the same folio multiple times as the seek interface iterates across each discontiguous data region in the folio. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09xfs: use byte ranges for write cleanup rangesDave Chinner
xfs_buffered_write_iomap_end() currently converts the byte ranges passed to it to filesystem blocks to pass them to the bmap code to punch out delalloc blocks, but then has to convert filesytem blocks back to byte ranges for page cache truncate. We're about to make the page cache truncate go away and replace it with a page cache walk, so having to convert everything to/from/to filesystem blocks is messy and error-prone. It is much easier to pass around byte ranges and convert to page indexes and/or filesystem blocks only where those units are needed. In preparation for the page cache walk being added, add a helper that converts byte ranges to filesystem blocks and calls xfs_bmap_punch_delalloc_range() and convert xfs_buffered_write_iomap_end() to calculate limits in byte ranges. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-11-09xfs: punching delalloc extents on write failure is racyDave Chinner
xfs_buffered_write_iomap_end() has a comment about the safety of punching delalloc extents based holding the IOLOCK_EXCL. This comment is wrong, and punching delalloc extents is not race free. When we punch out a delalloc extent after a write failure in xfs_buffered_write_iomap_end(), we punch out the page cache with truncate_pagecache_range() before we punch out the delalloc extents. At this point, we only hold the IOLOCK_EXCL, so there is nothing stopping mmap() write faults racing with this cleanup operation, reinstantiating a folio over the range we are about to punch and hence requiring the delalloc extent to be kept. If this race condition is hit, we can end up with a dirty page in the page cache that has no delalloc extent or space reservation backing it. This leads to bad things happening at writeback time. To avoid this race condition, we need the page cache truncation to be atomic w.r.t. the extent manipulation. We can do this by holding the mapping->invalidate_lock exclusively across this operation - this will prevent new pages from being inserted into the page cache whilst we are removing the pages and the backing extent and space reservation. Taking the mapping->invalidate_lock exclusively in the buffered write IO path is safe - it naturally nests inside the IOLOCK (see truncate and fallocate paths). iomap_zero_range() can be called from under the mapping->invalidate_lock (from the truncate path via either xfs_zero_eof() or xfs_truncate_page(), but iomap_zero_iter() will not instantiate new delalloc pages (because it skips holes) and hence will not ever need to punch out delalloc extents on failure. Fix the locking issue, and clean up the code logic a little to avoid unnecessary work if we didn't allocate the delalloc extent or wrote the entire region we allocated. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-11-09xfs: write page faults in iomap are not buffered writesDave Chinner
When we reserve a delalloc region in xfs_buffered_write_iomap_begin, we mark the iomap as IOMAP_F_NEW so that the the write context understands that it allocated the delalloc region. If we then fail that buffered write, xfs_buffered_write_iomap_end() checks for the IOMAP_F_NEW flag and if it is set, it punches out the unused delalloc region that was allocated for the write. The assumption this code makes is that all buffered write operations that can allocate space are run under an exclusive lock (i_rwsem). This is an invalid assumption: page faults in mmap()d regions call through this same function pair to map the file range being faulted and this runs only holding the inode->i_mapping->invalidate_lock in shared mode. IOWs, we can have races between page faults and write() calls that fail the nested page cache write operation that result in data loss. That is, the failing iomap_end call will punch out the data that the other racing iomap iteration brought into the page cache. This can be reproduced with generic/34[46] if we arbitrarily fail page cache copy-in operations from write() syscalls. Code analysis tells us that the iomap_page_mkwrite() function holds the already instantiated and uptodate folio locked across the iomap mapping iterations. Hence the folio cannot be removed from memory whilst we are mapping the range it covers, and as such we do not care if the mapping changes state underneath the iomap iteration loop: 1. if the folio is not already dirty, there is no writeback races possible. 2. if we allocated the mapping (delalloc or unwritten), the folio cannot already be dirty. See #1. 3. If the folio is already dirty, it must be up to date. As we hold it locked, it cannot be reclaimed from memory. Hence we always have valid data in the page cache while iterating the mapping. 4. Valid data in the page cache can exist when the underlying mapping is DELALLOC, UNWRITTEN or WRITTEN. Having the mapping change from DELALLOC->UNWRITTEN or UNWRITTEN->WRITTEN does not change the data in the page - it only affects actions if we are initialising a new page. Hence #3 applies and we don't care about these extent map transitions racing with iomap_page_mkwrite(). 5. iomap_page_mkwrite() checks for page invalidation races (truncate, hole punch, etc) after it locks the folio. We also hold the mapping->invalidation_lock here, and hence the mapping cannot change due to extent removal operations while we are iterating the folio. As such, filesystems that don't use bufferheads will never fail the iomap_folio_mkwrite_iter() operation on the current mapping, regardless of whether the iomap should be considered stale. Further, the range we are asked to iterate is limited to the range inside EOF that the folio spans. Hence, for XFS, we will only map the exact range we are asked for, and we will only do speculative preallocation with delalloc if we are mapping a hole at the EOF page. The iterator will consume the entire range of the folio that is within EOF, and anything beyond the EOF block cannot be accessed. We never need to truncate this post-EOF speculative prealloc away in the context of the iomap_page_mkwrite() iterator because if it remains unused we'll remove it when the last reference to the inode goes away. Hence we don't actually need an .iomap_end() cleanup/error handling path at all for iomap_page_mkwrite() for XFS. This means we can separate the page fault processing from the complexity of the .iomap_end() processing in the buffered write path. This also means that the buffered write path will also be able to take the mapping->invalidate_lock as necessary. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-11-09xfs: don't return -EFSCORRUPTED from repair when resources cannot be grabbedDarrick J. Wong
If we tried to repair something but the repair failed with -EDEADLOCK, that means that the repair function couldn't grab some resource it needed and wants us to try again. If we try again (with TRY_HARDER) but still can't get all the resources we need, the repair fails and errors remain on the filesystem. Right now, repair returns the -EDEADLOCK to the caller as -EFSCORRUPTED, which results in XFS_SCRUB_OFLAG_CORRUPT being passed out to userspace. This is not correct because repair has not determined that anything is corrupt. If the repair had been invoked on an object that could be optimized but wasn't corrupt (OFLAG_PREEN), the inability to grab resources will be reported to userspace as corrupt metadata, and users will be unnecessarily alarmed that their suboptimal metadata turned into a corruption. Fix this by returning zero so that the results of the actual scrub will be copied back out to userspace. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-09iomap: directly use logical block sizeKeith Busch
Don't transform the logical block size to a bit shift only to shift it back to the original block size. Just use the size. Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-11-08xfs: Print XFS UUID on mount and umount events.xfs-6.2-merge-1Lukas Herbolt
As of now only device names are printed out over __xfs_printk(). The device names are not persistent across reboots which in case of searching for origin of corruption brings another task to properly identify the devices. This patch add XFS UUID upon every mount/umount event which will make the identification much easier. Signed-off-by: Lukas Herbolt <lukas@herbolt.com> [sandeen: rebase onto current upstream kernel] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: fix incorrect error-out in xfs_removeDarrick J. Wong
Clean up resources if resetting the dotdot entry doesn't succeed. Observed through code inspection. Fixes: 5838d0356bb3 ("xfs: reset child dir '..' entry when unlinking child") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
2022-11-08xfs: teach scrub to flag non-extents format cow forksDarrick J. Wong
CoW forks only exist in memory, which means that they can only ever have an incore extent tree. Hence they must always be FMT_EXTENTS, so check this when we're scrubbing them. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: check that CoW fork extents are not sharedDarrick J. Wong
Ensure that extents in an inode's CoW fork are not marked as shared in the refcount btree. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: check quota files for unwritten extentsDarrick J. Wong
Teach scrub to flag quota files containing unwritten extents. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: block map scrub should handle incore delalloc reservationsDarrick J. Wong
Enhance the block map scrubber to check delayed allocation reservations. Though there are no physical space allocations to check, we do need to make sure that the range of file offsets being mapped are correct, and to bump the lastoff cursor so that key order checking works correctly. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: teach scrub to check for adjacent bmaps when rmap larger than bmapDarrick J. Wong
When scrub is checking file fork mappings against rmap records and the rmap record starts before or ends after the bmap record, check the adjacent bmap records to make sure that they're adjacent to the one we're checking. This helps us to detect cases where the rmaps cover territory that the bmaps do not. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: fix perag loop in xchk_bmap_check_rmapsDarrick J. Wong
sparse complains that we can return an uninitialized error from this function and that pag could be uninitialized. We know that there are no zero-AG filesystems and hence we had to call xchk_bmap_check_ag_rmaps at least once, so this is not actually possible, but I'm too worn out from automated complaints from unsophisticated AIs so let's just fix this and move on to more interesting problems, eh? Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: online checking of the free rt extent countDarrick J. Wong
Teach the summary count checker to count the number of free realtime extents and compare that to the superblock copy. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: skip fscounters comparisons when the scan is incompleteDarrick J. Wong
If any part of the per-AG summary counter scan loop aborts without collecting all of the data we need, the scrubber's observation data will be invalid. Set the incomplete flag so that we abort the scrub without reporting false corruptions. Document the data dependency here too. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: make rtbitmap ILOCKing consistent when scanning the rt bitmap fileDarrick J. Wong
xfs_rtalloc_query_range scans the realtime bitmap file in order of increasing file offset, so this caller can take ILOCK_SHARED on the rt bitmap inode instead of ILOCK_EXCL. This isn't going to yield any practical benefits at mount time, but we'd like to make the locking usage consistent around xfs_rtalloc_query_all calls. Make all the places we do this use the same xfs_ilock lockflags for consistency. Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: load rtbitmap and rtsummary extent mapping btrees at mount timeDarrick J. Wong
It turns out that GETFSMAP and online fsck have had a bug for years due to their use of ILOCK_SHARED to coordinate their linear scans of the realtime bitmap. If the bitmap file's data fork happens to be in BTREE format and the scan occurs immediately after mounting, the incore bmbt will not be populated, leading to ASSERTs tripping over the incorrect inode state. Because the bitmap scans always lock bitmap buffers in increasing order of file offset, it is appropriate for these two callers to take a shared ILOCK to improve scalability. To fix this problem, load both data and attr fork state into memory when mounting the realtime inodes. Realtime metadata files aren't supposed to have an attr fork so the second step is likely a nop. On most filesystems this is unlikely since the rtbitmap data fork is usually in extents format, but it's possible to craft a filesystem that will by fragmenting the free space in the data section and growfsing the rt section. Fixes: 4c934c7dd60c ("xfs: report realtime space information via the rtbitmap") Also-Fixes: 46d9bfb5e706 ("xfs: cross-reference the realtime bitmap") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: don't retry repairs harder when EAGAIN is returnedDarrick J. Wong
Repair functions will not return EAGAIN -- if they were not able to obtain resources, they should return EDEADLOCK (like the rest of online fsck) to signal that we need to grab all the resources and try again. Hence we don't need to deal with this case except as a debugging assertion. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: fix return code when fatal signal encountered during dquot scrubDarrick J. Wong
If the scrub process is sent a fatal signal while we're checking dquots, the predicate for this will set the error code to -EINTR. Don't then squash that into -ECANCELED, because the wrong errno turns up in the trace output. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: return EINTR when a fatal signal terminates scrubDarrick J. Wong
If the program calling online fsck is terminated with a fatal signal, bail out to userspace by returning EINTR, not EAGAIN. EAGAIN is used by scrubbers to indicate that we should try again with more resources locked, and not to indicate that the operation was cancelled. The miswiring is mostly harmless, but it shows up in the trace data. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: pivot online scrub away from kmem.[ch]Darrick J. Wong
Convert all the online scrub code to use the Linux slab allocator functions directly instead of going through the kmem wrappers. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: initialize the check_owner object fullyDarrick J. Wong
Initialize the check_owner list head so that we don't corrupt the list. Reduce the scope of the object pointer. Fixes: 858333dcf021 ("xfs: check btree block ownership with bnobt/rmapbt when scrubbing btree") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: standardize GFP flags usage in online scrubDarrick J. Wong
Memory allocation usage is the same throughout online fsck -- we want kernel memory, we have to be able to back out if we can't allocate memory, and we don't want to spray dmesg with memory allocation failure reports. Standardize the GFP flag usage and document these requirements. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: make AGFL repair function avoid crosslinked blocksDarrick J. Wong
Teach the AGFL repair function to check each block of the proposed AGFL against the rmap btree. If the rmapbt finds any mappings that are not OWN_AG, strike that block from the list. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: log the AGI/AGF buffers when rolling transactions during an AG repairDarrick J. Wong
Currently, the only way to lock an allocation group is to hold the AGI and AGF buffers. If a repair needs to roll the transaction while repairing some AG metadata, it maintains that lock by holding the two buffers across the transaction roll and joins them afterwards. However, repair is not like other parts of XFS that employ the bhold - roll - bjoin sequence because it's possible that the AGI or AGF buffers are not actually dirty before the roll. This presents two problems -- First, we need to redirty those buffers to keep them moving along in the log to avoid pinning the log tail. Second, a clean buffer log item can detach from the buffer. If this happens, the buffer type state is discarded along with the bli and must be reattached before the next time the buffer is logged. If it is not, the logging code will complain and log recovery will not work properly. An earlier version of this patch tried to fix the second problem by re-setting the buffer type in the bli after joining the buffer to the new transaction, but that looked weird and didn't solve the first problem. Instead, solve both problems by logging the buffer before rolling the transaction. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: don't track the AGFL buffer in the scrub AG contextDarrick J. Wong
While scrubbing an allocation group, we don't need to hold the AGFL buffer as part of the scrub context. All that is necessary to lock an AG is to hold the AGI and AGF buffers, so fix all the existing users of the AGFL buffer to grab them only when necessary. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: fully initialize xfs_da_args in xchk_directory_blocksDarrick J. Wong
While running the online fsck test suite, I noticed the following assertion in the kernel log (edited for brevity): XFS: Assertion failed: 0, file: fs/xfs/xfs_health.c, line: 571 ------------[ cut here ]------------ WARNING: CPU: 3 PID: 11667 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs] CPU: 3 PID: 11667 Comm: xfs_scrub Tainted: G W 5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:assfail+0x46/0x4a [xfs] Call Trace: <TASK> xfs_dir2_isblock+0xcc/0xe0 xchk_directory_blocks+0xc7/0x420 xchk_directory+0x53/0xb0 xfs_scrub_metadata+0x2b6/0x6b0 xfs_scrubv_metadata+0x35e/0x4d0 xfs_ioc_scrubv_metadata+0x111/0x160 xfs_file_ioctl+0x4ec/0xef0 __x64_sys_ioctl+0x82/0xa0 do_syscall_64+0x2b/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 This assertion triggers in xfs_dirattr_mark_sick when the caller passes in a whichfork value that is neither of XFS_{DATA,ATTR}_FORK. The cause of this is that xchk_directory_blocks only partially initializes the xfs_da_args structure that is passed to xfs_dir2_isblock. If the data fork is not correct, the XFS_IS_CORRUPT clause will trigger. My development branch reports this failure to the health monitoring subsystem, which accesses the uninitialized args->whichfork field, leading the the assertion tripping. We really shouldn't be passing random stack contents around, so the solution here is to force the compiler to zero-initialize the struct. Found by fuzzing u3.bmx[0].blockcount = middlebit on xfs/1554. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-11-08xfs: fix sb write verify for lazysbcountLong Li
When lazysbcount is enabled, fsstress and loop mount/unmount test report the following problems: XFS (loop0): SB summary counter sanity check failed XFS (loop0): Metadata corruption detected at xfs_sb_write_verify+0x13b/0x460, xfs_sb block 0x0 XFS (loop0): Unmount and run xfs_repair XFS (loop0): First 128 bytes of corrupted metadata buffer: 00000000: 58 46 53 42 00 00 10 00 00 00 00 00 00 28 00 00 XFSB.........(.. 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000020: 69 fb 7c cd 5f dc 44 af 85 74 e0 cc d4 e3 34 5a i.|._.D..t....4Z 00000030: 00 00 00 00 00 20 00 06 00 00 00 00 00 00 00 80 ..... .......... 00000040: 00 00 00 00 00 00 00 81 00 00 00 00 00 00 00 82 ................ 00000050: 00 00 00 01 00 0a 00 00 00 00 00 04 00 00 00 00 ................ 00000060: 00 00 0a 00 b4 b5 02 00 02 00 00 08 00 00 00 00 ................ 00000070: 00 00 00 00 00 00 00 00 0c 09 09 03 14 00 00 19 ................ XFS (loop0): Corruption of in-memory data (0x8) detected at _xfs_buf_ioapply +0xe1e/0x10e0 (fs/xfs/xfs_buf.c:1580). Shutting down filesystem. XFS (loop0): Please unmount the filesystem and rectify the problem(s) XFS (loop0): log mount/recovery failed: error -117 XFS (loop0): log mount failed This corruption will shutdown the file system and the file system will no longer be mountable. The following script can reproduce the problem, but it may take a long time. #!/bin/bash device=/dev/sda testdir=/mnt/test round=0 function fail() { echo "$*" exit 1 } mkdir -p $testdir while [ $round -lt 10000 ] do echo "******* round $round ********" mkfs.xfs -f $device mount $device $testdir || fail "mount failed!" fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null & sleep 4 killall -w fsstress umount $testdir xfs_repair -e $device > /dev/null if [ $? -eq 2 ];then echo "ERR CODE 2: Dirty log exception during repair." exit 1 fi round=$(($round+1)) done With lazysbcount is enabled, There is no additional lock protection for reading m_ifree and m_icount in xfs_log_sb(), if other cpu modifies the m_ifree, this will make the m_ifree greater than m_icount. For example, consider the following sequence and ifreedelta is postive: CPU0 CPU1 xfs_log_sb xfs_trans_unreserve_and_mod_sb ---------- ------------------------------ percpu_counter_sum(&mp->m_icount) percpu_counter_add_batch(&mp->m_icount, idelta, XFS_ICOUNT_BATCH) percpu_counter_add(&mp->m_ifree, ifreedelta); percpu_counter_sum(&mp->m_ifree) After this, incorrect inode count (sb_ifree > sb_icount) will be writen to the log. In the subsequent writing of sb, incorrect inode count (sb_ifree > sb_icount) will fail to pass the boundary check in xfs_validate_sb_write() that cause the file system shutdown. When lazysbcount is enabled, we don't need to guarantee that Lazy sb counters are completely correct, but we do need to guarantee that sb_ifree <= sb_icount. On the other hand, the constraint that m_ifree <= m_icount must be satisfied any time that there /cannot/ be other threads allocating or freeing inode chunks. If the constraint is violated under these circumstances, sb_i{count,free} (the ondisk superblock inode counters) maybe incorrect and need to be marked sick at unmount, the count will be rebuilt on the next mount. Fixes: 8756a5af1819 ("libxfs: add more bounds checking to sb sanity checks") Signed-off-by: Long Li <leo.lilong@huawei.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-11-06Linux 6.1-rc4v6.1-rc4Linus Torvalds
2022-11-06Merge tag 'cxl-fixes-for-6.1-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl fixes from Dan Williams: "Several fixes for CXL region creation crashes, leaks and failures. This is mainly fallout from the original implementation of dynamic CXL region creation (instantiate new physical memory pools) that arrived in v6.0-rc1. Given the theme of "failures in the presence of pass-through decoders" this also includes new regression test infrastructure for that case. Summary: - Fix region creation crash with pass-through decoders - Fix region creation crash when no decoder allocation fails - Fix region creation crash when scanning regions to enforce the increasing physical address order constraint that CXL mandates - Fix a memory leak for cxl_pmem_region objects, track 1:N instead of 1:1 memory-device-to-region associations. - Fix a memory leak for cxl_region objects when regions with active targets are deleted - Fix assignment of NUMA nodes to CXL regions by CFMWS (CXL Window) emulated proximity domains. - Fix region creation failure for switch attached devices downstream of a single-port host-bridge - Fix false positive memory leak of cxl_region objects by recycling recently used region ids rather than freeing them - Add regression test infrastructure for a pass-through decoder configuration - Fix some mailbox payload handling corner cases" * tag 'cxl-fixes-for-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/region: Recycle region ids cxl/region: Fix 'distance' calculation with passthrough ports tools/testing/cxl: Add a single-port host-bridge regression config tools/testing/cxl: Fix some error exits cxl/pmem: Fix cxl_pmem_region and cxl_memdev leak cxl/region: Fix cxl_region leak, cleanup targets at region delete cxl/region: Fix region HPA ordering validation cxl/pmem: Use size_add() against integer overflow cxl/region: Fix decoder allocation crash ACPI: NUMA: Add CXL CFMWS 'nodes' to the possible nodes set cxl/pmem: Fix failure to account for 8 byte header for writes to the device LSA. cxl/region: Fix null pointer dereference due to pass through decoder commit cxl/mbox: Add a check on input payload size
2022-11-06Merge tag 'hwmon-for-v6.1-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging Pull hwmon fixes from Guenter Roeck: "Fix two regressions: - Commit 54cc3dbfc10d ("hwmon: (pmbus) Add regulator supply into macro") resulted in regulator undercount when disabling regulators. Revert it. - The thermal subsystem rework caused the scmi driver to no longer register with the thermal subsystem because index values no longer match. To fix the problem, the scmi driver now directly registers with the thermal subsystem, no longer through the hwmon core" * tag 'hwmon-for-v6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: Revert "hwmon: (pmbus) Add regulator supply into macro" hwmon: (scmi) Register explicitly with Thermal Framework
2022-11-06Merge tag 'perf_urgent_for_v6.1_rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Add Cooper Lake's stepping to the PEBS guest/host events isolation fixed microcode revisions checking quirk - Update Icelake and Sapphire Rapids events constraints - Use the standard energy unit for Sapphire Rapids in RAPL - Fix the hw_breakpoint test to fail more graciously on !SMP configs * tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[] perf/x86/intel: Fix pebs event constraints for SPR perf/x86/intel: Fix pebs event constraints for ICL perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain perf/hw_breakpoint: test: Skip the test if dependencies unmet
2022-11-06Merge tag 'x86_urgent_for_v6.1_rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add new Intel CPU models - Enforce that TDX guests are successfully loaded only on TDX hardware where virtualization exception (#VE) delivery on kernel memory is disabled because handling those in all possible cases is "essentially impossible" - Add the proper include to the syscall wrappers so that BTF can see the real pt_regs definition and not only the forward declaration * tag 'x86_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add several Intel server CPU model numbers x86/tdx: Panic on bad configs that #VE on "private" memory access x86/tdx: Prepare for using "INFO" call for a second purpose x86/syscall: Include asm/ptrace.h in syscall_wrapper header
2022-11-06Merge tag 'kbuild-fixes-v6.1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Use POSIX-compatible grep options - Document git-related tips for reproducible builds - Fix a typo in the modpost rule - Suppress SIGPIPE error message from gcc-ar and llvm-ar - Fix segmentation fault in the menuconfig search * tag 'kbuild-fixes-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: fix segmentation fault in menuconfig search kbuild: fix SIGPIPE error message for AR=gcc-ar and AR=llvm-ar kbuild: fix typo in modpost Documentation: kbuild: Add description of git for reproducible builds kbuild: use POSIX-compatible grep option
2022-11-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix the pKVM stage-1 walker erronously using the stage-2 accessor - Correctly convert vcpu->kvm to a hyp pointer when generating an exception in a nVHE+MTE configuration - Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them - Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE - Document the boot requirements for FGT when entering the kernel at EL1 x86: - Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() - Make argument order consistent for kvcalloc() - Userspace API fixes for DEBUGCTL and LBRs" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Fix a typo about the usage of kvcalloc() KVM: x86: Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl() KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs arm64: booting: Document our requirements for fine grained traps with SME KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling them KVM: arm64: Fix bad dereference on MTE-enabled systems KVM: arm64: Use correct accessor to parse stage-1 PTEs
2022-11-06Merge tag 'for-linus-6.1-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "One fix for silencing a smatch warning, and a small cleanup patch" * tag 'for-linus-6.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: simplify sysenter and syscall setup x86/xen: silence smatch warning in pmu_msr_chk_emulated()
2022-11-06Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Fix a number of bugs, including some regressions, the most serious of which was one which would cause online resizes to fail with file systems with metadata checksums enabled. Also fix a warning caused by the newly added fortify string checker, plus some bugs that were found using fuzzed file systems" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix fortify warning in fs/ext4/fast_commit.c:1551 ext4: fix wrong return err in ext4_load_and_init_journal() ext4: fix warning in 'ext4_da_release_space' ext4: fix BUG_ON() when directory entry has invalid rec_len ext4: update the backup superblock's at the end of the online resize
2022-11-06Merge tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs fixes from Steve French: "One symlink handling fix and two fixes foir multichannel issues with iterating channels, including for oplock breaks when leases are disabled" * tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix use-after-free on the link name cifs: avoid unnecessary iteration of tcp sessions cifs: always iterate smb sessions using primary channel
2022-11-06Merge tag 'trace-v6.1-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull `lTracing fixes for 6.1-rc3: - Fixed NULL pointer dereference in the ring buffer wait-waiters code for machines that have less CPUs than what nr_cpu_ids returns. The buffer array is of size nr_cpu_ids, but only the online CPUs get initialized. - Fixed use after free call in ftrace_shutdown. - Fix accounting of if a kprobe is enabled - Fix NULL pointer dereference on error path of fprobe rethook_alloc(). - Fix unregistering of fprobe_kprobe_handler - Fix memory leak in kprobe test module * tag 'trace-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd() tracing/fprobe: Fix to check whether fprobe is registered correctly fprobe: Check rethook_alloc() return in rethook initialization kprobe: reverse kp->flags when arm_kprobe failed ftrace: Fix use-after-free for dynamic ftrace_ops ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()