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* xfs: don't use current->journal_infoDave Chinner2024-03-254-21/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot reported an ext4 panic during a page fault where found a journal handle when it didn't expect to find one. The structure it tripped over had a value of 'TRAN' in the first entry in the structure, and that indicates it tripped over a struct xfs_trans instead of a jbd2 handle. The reason for this is that the page fault was taken during a copy-out to a user buffer from an xfs bulkstat operation. XFS uses an "empty" transaction context for bulkstat to do automated metadata buffer cleanup, and so the transaction context is valid across the copyout of the bulkstat info into the user buffer. We are using empty transaction contexts like this in XFS to reduce the risk of failing to release objects we reference during the operation, especially during error handling. Hence we really need to ensure that we can take page faults from these contexts without leaving landmines for the code processing the page fault to trip over. However, this same behaviour could happen from any other filesystem that triggers a page fault or any other exception that is handled on-stack from within a task context that has current->journal_info set. Having a page fault from some other filesystem bounce into XFS where we have to run a transaction isn't a bug at all, but the usage of current->journal_info means that this could result corruption of the outer task's journal_info structure. The problem is purely that we now have two different contexts that now think they own current->journal_info. IOWs, no filesystem can allow page faults or on-stack exceptions while current->journal_info is set by the filesystem because the exception processing might use current->journal_info itself. If we end up with nested XFS transactions whilst holding an empty transaction, then it isn't an issue as the outer transaction does not hold a log reservation. If we ignore the current->journal_info usage, then the only problem that might occur is a deadlock if the exception tries to take the same locks the upper context holds. That, however, is not a problem that setting current->journal_info would solve, so it's largely an irrelevant concern here. IOWs, we really only use current->journal_info for a warning check in xfs_vm_writepages() to ensure we aren't doing writeback from a transaction context. Writeback might need to do allocation, so it can need to run transactions itself. Hence it's a debug check to warn us that we've done something silly, and largely it is not all that useful. So let's just remove all the use of current->journal_info in XFS and get rid of all the potential issues from nested contexts where current->journal_info might get misused by another filesystem context. Reported-by: syzbot+cdee56dbcdf0096ef605@syzkaller.appspotmail.com Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Mark Tinguely <mark.tinguely@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* xfs: allow sunit mount option to repair bad primary sb stripe valuesDave Chinner2024-03-252-11/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a filesystem has a busted stripe alignment configuration on disk (e.g. because broken RAID firmware told mkfs that swidth was smaller than sunit), then the filesystem will refuse to mount due to the stripe validation failing. This failure is triggering during distro upgrades from old kernels lacking this check to newer kernels with this check, and currently the only way to fix it is with offline xfs_db surgery. This runtime validity checking occurs when we read the superblock for the first time and causes the mount to fail immediately. This prevents the rewrite of stripe unit/width via mount options that occurs later in the mount process. Hence there is no way to recover this situation without resorting to offline xfs_db rewrite of the values. However, we parse the mount options long before we read the superblock, and we know if the mount has been asked to re-write the stripe alignment configuration when we are reading the superblock and verifying it for the first time. Hence we can conditionally ignore stripe verification failures if the mount options specified will correct the issue. We validate that the new stripe unit/width are valid before we overwrite the superblock values, so we can ignore the invalid config at verification and fail the mount later if the new values are not valid. This, at least, gives users the chance of correcting the issue after a kernel upgrade without having to resort to xfs-db hacks. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* Merge tag 'xfs-6.9-merge-9' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2024-03-223-9/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | Pull xfs fixes from Chandan Babu: - Fix invalid pointer dereference by initializing xmbuf before tracepoint function is invoked - Use memalloc_nofs_save() when inserting into quota radix tree * tag 'xfs-6.9-merge-9' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: quota radix tree allocations need to be NOFS on insert xfs: fix dev_t usage in xmbuf tracepoints
| * xfs: quota radix tree allocations need to be NOFS on insertDave Chinner2024-03-151-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In converting the XFS code from GFP_NOFS to scoped contexts, we converted the quota radix tree to GFP_KERNEL. Unfortunately, it was not clearly documented that this set was because there is a dependency on the quotainfo->qi_tree_lock being taken in memory reclaim to remove dquots from the radix tree. In hindsight this is obvious, but the radix tree allocations on insert are not immediately obvious, and we avoid this for the inode cache radix trees by using preloading and hence completely avoiding the radix tree node allocation under tree lock constraints. Hence there are a few solutions here. The first is to reinstate GFP_NOFS for the radix tree and add a comment explaining why GFP_NOFS is used. The second is to use memalloc_nofs_save() on the radix tree insert context, which makes it obvious that the radix tree insert runs under GFP_NOFS constraints. The third option is to simply replace the radix tree and it's lock with an xarray which can do memory allocation safely in an insert context. The first is OK, but not really the direction we want to head. The second is my preferred short term solution. The third - converting XFS radix trees to xarray - is the longer term solution. Hence to fix the regression here, we take option 2 as it moves us in the direction we want to head with memory allocation and GFP_NOFS removal. Reported-by: syzbot+8fdff861a781522bda4d@syzkaller.appspotmail.com Reported-by: syzbot+d247769793ec169e4bf9@syzkaller.appspotmail.com Fixes: 94a69db2367e ("xfs: use __GFP_NOLOCKDEP instead of GFP_NOFS") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: fix dev_t usage in xmbuf tracepointsDarrick J. Wong2024-03-152-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix some inconsistencies in the xmbuf tracepoints -- they should be reporting the major/minor of the filesystem that they're associated with, so that we have some clue on whose behalf the xmbuf was created. Fix the xmbuf_free tracepoint to report the same. Don't call the trace function until the xmbuf is fully initialized. Fixes: 5076a6040ca1 ("xfs: support in-memory buffer cache target") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
* | Merge tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2024-03-13176-3515/+13139
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull xfs updates from Chandan Babu: - Online repair updates: - More ondisk structures being repaired: - Inode's mode field by trying to obtain file type value from the a directory entry - Quota counters - Link counts of inodes - FS summary counters - Support for in-memory btrees has been added to support repair of rmap btrees - Misc changes: - Report corruption of metadata to the health tracking subsystem - Enable indirect health reporting when resources are scarce - Reduce memory usage while repairing refcount btree - Extend "Bmap update" intent item to support atomic extent swapping on the realtime device - Extend "Bmap update" intent item to support extended attribute fork and unwritten extents - Code cleanups: - Bmap log intent - Btree block pointer checking - Btree readahead - Buffer target - Symbolic link code - Remove mrlock wrapper around the rwsem - Convert all the GFP_NOFS flag usages to use the scoped memalloc_nofs_save() API instead of direct calls with the GFP_NOFS - Refactor and simplify xfile abstraction. Lower level APIs in shmem.c are required to be exported in order to achieve this - Skip checking alignment constraints for inode chunk allocations when block size is larger than inode chunk size - Do not submit delwri buffers collected during log recovery when an error has been encountered - Fix SEEK_HOLE/DATA for file regions which have active COW extents - Fix lock order inversion when executing error handling path during shrinking a filesystem - Remove duplicate ifdefs * tag 'xfs-6.9-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (183 commits) xfs: shrink failure needs to hold AGI buffer mm/shmem.c: Use new form of *@param in kernel-doc kernel-doc: Add unary operator * to $type_param_ref xfs: use kvfree() in xlog_cil_free_logvec() xfs: xfs_btree_bload_prep_block() should use __GFP_NOFAIL xfs: fix scrub stats file permissions xfs: fix log recovery erroring out on refcount recovery failure xfs: move symlink target write function to libxfs xfs: move remote symlink target read function to libxfs xfs: move xfs_symlink_remote.c declarations to xfs_symlink_remote.h xfs: xfs_bmap_finish_one should map unwritten extents properly xfs: support deferred bmap updates on the attr fork xfs: support recovering bmap intent items targetting realtime extents xfs: add a realtime flag to the bmap update log redo items xfs: add a xattr_entry helper xfs: fix xfs_bunmapi to allow unmapping of partial rt extents xfs: move xfs_bmap_defer_add to xfs_bmap_item.c xfs: reuse xfs_bmap_update_cancel_item xfs: add a bi_entry helper xfs: remove xfs_trans_set_bmap_flags ...
| * xfs: shrink failure needs to hold AGI bufferDave Chinner2024-03-071-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chandan reported a AGI/AGF lock order hang on xfs/168 during recent testing. The cause of the problem was the task running xfs_growfs to shrink the filesystem. A failure occurred trying to remove the free space from the btrees that the shrink would make disappear, and that meant it ran the error handling for a partial failure. This error path involves restoring the per-ag block reservations, and that requires calculating the amount of space needed to be reserved for the free inode btree. The growfs operation hung here: [18679.536829] down+0x71/0xa0 [18679.537657] xfs_buf_lock+0xa4/0x290 [xfs] [18679.538731] xfs_buf_find_lock+0xf7/0x4d0 [xfs] [18679.539920] xfs_buf_lookup.constprop.0+0x289/0x500 [xfs] [18679.542628] xfs_buf_get_map+0x2b3/0xe40 [xfs] [18679.547076] xfs_buf_read_map+0xbb/0x900 [xfs] [18679.562616] xfs_trans_read_buf_map+0x449/0xb10 [xfs] [18679.569778] xfs_read_agi+0x1cd/0x500 [xfs] [18679.573126] xfs_ialloc_read_agi+0xc2/0x5b0 [xfs] [18679.578708] xfs_finobt_calc_reserves+0xe7/0x4d0 [xfs] [18679.582480] xfs_ag_resv_init+0x2c5/0x490 [xfs] [18679.586023] xfs_ag_shrink_space+0x736/0xd30 [xfs] [18679.590730] xfs_growfs_data_private.isra.0+0x55e/0x990 [xfs] [18679.599764] xfs_growfs_data+0x2f1/0x410 [xfs] [18679.602212] xfs_file_ioctl+0xd1e/0x1370 [xfs] trying to get the AGI lock. The AGI lock was held by a fstress task trying to do an inode allocation, and it was waiting on the AGF lock to allocate a new inode chunk on disk. Hence deadlock. The fix for this is for the growfs code to hold the AGI over the transaction roll it does in the error path. It already holds the AGF locked across this, and that is what causes the lock order inversion in the xfs_ag_resv_init() call. Reported-by: Chandan Babu R <chandanbabu@kernel.org> Fixes: 46141dc891f7 ("xfs: introduce xfs_ag_shrink_space()") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: use kvfree() in xlog_cil_free_logvec()Dave Chinner2024-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The xfs_log_vec items are allocated by xlog_kvmalloc(), and so need to be freed with kvfree. This was missed when coverting from the kmem_free() API. Fixes: 49292576136f ("xfs: convert kmem_free() for kvmalloc users to kvfree()") Reported-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: xfs_btree_bload_prep_block() should use __GFP_NOFAILDave Chinner2024-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | This was missed in the conversion from KM* flags. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: fix scrub stats file permissionsDarrick J. Wong2024-02-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the kernel is in lockdown mode, debugfs will only show files that are world-readable and cannot be written, mmaped, or used with ioctl. That more or less describes the scrub stats file, except that the permissions are wrong -- they should be 0444, not 0644. You can't write the stats file, so the 0200 makes no sense. Meanwhile, the clear_stats file is only writable, but it got mode 0400 instead of 0200, which would make more sense. Fix both files so that they make sense. Fixes: d7a74cad8f451 ("xfs: track usage statistics of online fsck") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: fix log recovery erroring out on refcount recovery failureDarrick J. Wong2024-02-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Per the comment in the error case of xfs_reflink_recover_cow, zero out any error (after shutting down the log) so that we actually kill any new intent items that might have gotten logged by later recovery steps. Discovered by xfs/434, which few people actually seem to run. Fixes: 2c1e31ed5c88 ("xfs: place intent recovery under NOFS allocation context") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
| * xfs: move symlink target write function to libxfsDarrick J. Wong2024-02-223-64/+84
| | | | | | | | | | | | | | | | Move xfs_symlink_write_target to xfs_symlink_remote.c so that kernel and mkfs can share the same function. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: move remote symlink target read function to libxfsDarrick J. Wong2024-02-225-77/+80
| | | | | | | | | | | | | | | | | | | | Move xfs_readlink_bmap_ilocked to xfs_symlink_remote.c so that the swapext code can use it to convert a remote format symlink back to shortform format after a metadata repair. While we're at it, fix a broken printf prefix. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: move xfs_symlink_remote.c declarations to xfs_symlink_remote.hDarrick J. Wong2024-02-228-14/+28
| | | | | | | | | | | | | | | | Move declarations for libxfs symlink functions into a separate header file like we do for most everything else. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: xfs_bmap_finish_one should map unwritten extents properlyDarrick J. Wong2024-02-221-0/+2
| | | | | | | | | | | | | | | | | | The deferred bmap work state and the log item can transmit unwritten state, so the XFS_BMAP_MAP handler must map in extents with that unwritten state. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: support deferred bmap updates on the attr forkDarrick J. Wong2024-02-224-38/+29
| | | | | | | | | | | | | | | | The deferred bmap update log item has always supported the attr fork, so plumb this in so that higher layers can access this. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: support recovering bmap intent items targetting realtime extentsDarrick J. Wong2024-02-221-0/+9
| | | | | | | | | | | | | | | | Now that we have reflink on the realtime device, bmap intent items have to support remapping extents on the realtime volume. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: add a realtime flag to the bmap update log redo itemsDarrick J. Wong2024-02-223-6/+29
| | | | | | | | | | | | | | | | | | Extend the bmap update (BUI) log items with a new realtime flag that indicates that the updates apply against a realtime file's data fork. We'll wire up the actual code later. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: fix xfs_bunmapi to allow unmapping of partial rt extentsDarrick J. Wong2024-02-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When XFS_BMAPI_REMAP is passed to bunmapi, that means that we want to remove part of a block mapping without touching the allocator. For realtime files with rtextsize > 1, that also means that we should skip all the code that changes a partial remove request into an unwritten extent conversion. IOWs, bunmapi in this mode should handle removing the mapping from the rt file and nothing else. Note that XFS_BMAPI_REMAP callers are required to decrement the reference count and/or free the space manually. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: add a xattr_entry helperDarrick J. Wong2024-02-221-4/+7
| | | | | | | | | | | | | | | | | | | | Add a helper to translate from the item list head to the attr_intent item structure and use it so shorten assignments and avoid the need for extra local variables. Inspired-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: move xfs_bmap_defer_add to xfs_bmap_item.cDarrick J. Wong2024-02-224-8/+20
| | | | | | | | | | | | | | | | | | | | | | | | Move the code that adds the incore xfs_bmap_item deferred work data to a transaction live with the BUI log item code. This means that the file mapping code no longer has to know about the inner workings of the BUI log items. As a consequence, we can hide the _get_group helper. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: reuse xfs_bmap_update_cancel_itemDarrick J. Wong2024-02-221-13/+12
| | | | | | | | | | | | | | | | | | Reuse xfs_bmap_update_cancel_item to put the AG/RTG and free the item in a few places that currently open code the logic. Inspired-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: add a bi_entry helperDarrick J. Wong2024-02-221-10/+9
| | | | | | | | | | | | | | | | | | | | Add a helper to translate from the item list head to the bmap_intent structure and use it so shorten assignments and avoid the need for extra local variables. Inspired-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: remove xfs_trans_set_bmap_flagsDarrick J. Wong2024-02-221-25/+13
| | | | | | | | | | | | | | Remove this single-use helper. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: clean up bmap log intent item tracepoint callsitesDarrick J. Wong2024-02-224-47/+33
| | | | | | | | | | | | | | | | Pass the incore bmap structure to the tracepoints instead of open-coding the argument passing. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: split tracepoint classes for deferred itemsDarrick J. Wong2024-02-221-85/+166
| | | | | | | | | | | | | | | | | | We're about to start adding support for deferred log intent items for realtime extents, so split these four types into separate classes so that we can customize them as the transition happens. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: port refcount repair to the new refcount bag structureDarrick J. Wong2024-02-224-107/+81
| | | | | | | | | | | | | | | | Port the refcount record generating code to use the new refcount bag data structure. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: create refcount bag structure for btree repairsDarrick J. Wong2024-02-225-0/+401
| | | | | | | | | | | | | | | | Create a bag structure for refcount information that uses the refcount bag btree defined in the previous patch. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: define an in-memory btree for storing refcount bag info during repairsDarrick J. Wong2024-02-225-1/+390
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a new in-memory btree type so that we can store refcount bag info in a much more memory-efficient and performant format. Recall that the refcount recordset regenerator computes the new recordset from browsing the rmap records. Let's say that the rmap records are: {agbno: 10, length: 40, ...} {agbno: 11, length: 3, ...} {agbno: 12, length: 20, ...} {agbno: 15, length: 1, ...} It is convenient to have a data structure that could quickly tell us the refcount for an arbitrary agbno without wasting memory. An array or a list could do that pretty easily. List suck because of the pointer overhead. xfarrays are a lot more compact, but we want to minimize sparse holes in the xfarray to constrain memory usage. Maintaining any kind of record order isn't needed for correctness, so I created the "rcbag", which is shorthand for an unordered list of (excerpted) reverse mappings. So we add the first rmap to the rcbag, and it looks like: 0: {agbno: 10, length: 40} The refcount for agbno 10 is 1. Then we move on to block 11, so we add the second rmap: 0: {agbno: 10, length: 40} 1: {agbno: 11, length: 3} The refcount for agbno 11 is 2. We move on to block 12, so we add the third: 0: {agbno: 10, length: 40} 1: {agbno: 11, length: 3} 2: {agbno: 12, length: 20} The refcount for agbno 12 and 13 is 3. We move on to block 14, and remove the second rmap: 0: {agbno: 10, length: 40} 1: NULL 2: {agbno: 12, length: 20} The refcount for agbno 14 is 2. We move on to block 15, and add the last rmap. But we don't care where it is and we don't want to expand the array so we put it in slot 1: 0: {agbno: 10, length: 40} 1: {agbno: 15, length: 1} 2: {agbno: 12, length: 20} The refcount for block 15 is 3. Notice how order doesn't matter in this list? That's why repair uses an unordered list, or "bag". The data structure is not a set because it does not guarantee uniqueness. That said, adding and removing specific items is now an O(n) operation because we have no idea where that item might be in the list. Overall, the runtime is O(n^2) which is bad. I realized that I could easily refactor the btree code and reimplement the refcount bag with an xfbtree. Adding and removing is now O(log2 n), so the runtime is at least O(n log2 n), which is much faster. In the end, the rcbag becomes a sorted list, but that's merely a detail of the implementation. The repair code doesn't care. (Note: That horrible xfs_db bmap_inflate command can be used to exercise this sort of rcbag insanity by cranking up refcounts quickly.) Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: hook live rmap operations during a repair operationDarrick J. Wong2024-02-2212-39/+392
| | | | | | | | | | | | | | | | | | Hook the regular rmap code when an rmapbt repair operation is running so that we can unlock the AGF buffer to scan the filesystem and keep the in-memory btree up to date during the scan. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: create a shadow rmap btree during rmap repairDarrick J. Wong2024-02-229-84/+377
| | | | | | | | | | | | | | | | Create an in-memory btree of rmap records instead of an array. This enables us to do live record collection instead of freezing the fs. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: repair the rmapbtDarrick J. Wong2024-02-2218-19/+1608
| | | | | | | | | | | | | | | | | | | | | | Rebuild the reverse mapping btree from all primary metadata. This first patch establishes the bare mechanics of finding records and putting together a new ondisk tree; more complex pieces are needed to make it work properly. Link: Documentation/filesystems/xfs-online-fsck-design.rst Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: create agblock bitmap helper to count the number of set regionsDarrick J. Wong2024-02-223-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the next patch, the rmap btree repair code will need to estimate the size of the new ondisk rmapbt. The size is a function of the number of records that will be written to disk, and the size of the recordset is the number of observations made while scanning the filesystem plus the number of OWN_AG records that will be injected into the rmap btree. OWN_AG rmap records track the free space btrees, the AGFL, and the new rmap btree itself. The repair tool uses a bitmap to record the space used for all four structures, which is why we need a function to count the number of set regions. A reviewer requested that this be pulled into a separate patch with its own justification, so here it is. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: create a helper to decide if a file mapping targets the rt volumeDarrick J. Wong2024-02-224-4/+14
| | | | | | | | | | | | | | | | Create a helper so that we can stop open-coding this decision everywhere. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: launder in-memory btree buffers before transaction commitDarrick J. Wong2024-02-227-0/+236
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we've noted in various places, all current users of in-memory btrees are online fsck. Online fsck only stages a btree long enough to rebuild an ondisk data structure, which means that the in-memory btree is ephemeral. Furthermore, if we encounter /any/ errors while updating an in-memory btree, all we do is tear down all the staged data and return an errno to userspace. In-memory btrees need not be transactional, so their buffers should not be committed to the ondisk log, nor should they be checkpointed by the AIL. That's just as well since the ephemeral nature of the btree means that the buftarg and the buffers may disappear quickly anyway. Therefore, we need a way to launder the btree buffers that get attached to the transaction by the generic btree code. Because the buffers are directly mapped to backing file pages, there's no need to bwrite them back to the tmpfs file. All we need to do is clean enough of the buffer log item state so that the bli can be detached from the buffer, remove the bli from the transaction's log item list, and reset the transaction dirty state as if the laundered items had never been there. For simplicity, create xfbtree transaction commit and cancel helpers that launder the in-memory btree buffers for callers. Once laundered, call the write verifier on non-stale buffers to avoid integrity issues, or punch a hole in the backing file for stale buffers. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: support in-memory btreesDarrick J. Wong2024-02-2213-39/+673
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Adapt the generic btree cursor code to be able to create a btree whose buffers come from a (presumably in-memory) buftarg with a header block that's specific to in-memory btrees. We'll connect this to other parts of online scrub in the next patches. Note that in-memory btrees always have a block size matching the system memory page size for efficiency reasons. There are also a few things we need to do to finalize a btree update; that's covered in the next patch. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: add a xfs_btree_ptrs_equal helperChristoph Hellwig2024-02-221-13/+17
| | | | | | | | | | | | | | | | | | | | This only has a single caller and thus might be a bit questionable, but I think it really improves the readability of xfs_btree_visit_block. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: support in-memory buffer cache targetsDarrick J. Wong2024-02-228-46/+369
| | | | | | | | | | | | | | | | | | | | | | | | | | Allow the buffer cache to target in-memory files by making it possible to have a buftarg that maps pages from private shmem files. As the prevous patch alludes, the in-memory buftarg contains its own cache, points to a shmem file, and does not point to a block_device. The next few patches will make it possible to construct an xfs_btree in pageable memory by using this buftarg. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: teach buftargs to maintain their own buffer hashtableDarrick J. Wong2024-02-225-38/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cached buffers are indexed by per-AG hashtables. This works great for the data device, but won't work for in-memory btrees. To handle that use case, buftargs will need to be able to index buffers independently of other data structures. We accomplish this by hoisting the rhashtable and its lock into a separate xfs_buf_cache structure, make the buftarg point to the _buf_cache structure, and rework various functions to use it. This will enable the in-memory buftarg to come up with its own _buf_cache. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * xfs: move setting bt_logical_sectorsize out of xfs_setsize_buftargChristoph Hellwig2024-02-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | bt_logical_sectorsize and the associated mask is set based on the constant logical block size in the block_device structure and thus doesn't need to be updated in xfs_setsize_buftarg. Move it into xfs_alloc_buftarg so that it is only done once per buftarg. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: remove xfs_setsize_buftarg_earlyChristoph Hellwig2024-02-221-15/+7
| | | | | | | | | | | | | | | | | | Open code the logic in the only caller, and improve the comment explaining what is being done here. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: remove the xfs_buftarg_t typedefChristoph Hellwig2024-02-224-16/+16
| | | | | | | | | | | | | | | | Switch the few remaining holdouts to the struct version. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: split xfs_buf_rele for cached vs uncached buffersChristoph Hellwig2024-02-221-15/+31
| | | | | | | | | | | | | | | | | | | | | | | | xfs_buf_rele is a bit confusing because it mixes up handling of normal cached and the special uncached buffers without much explanation. Split the handling into two different helpers, and use a clearly named helper that checks the hash key to distinguish the two cases instead of checking the pag pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: move and rename xfs_btree_read_buflChristoph Hellwig2024-02-223-51/+25
| | | | | | | | | | | | | | | | | | | | | | Despite its name, xfs_btree_read_bufl doesn't contain any btree-related functionaliy and isn't used by the btree code. Move it to xfs_bmap.c, hard code the refval and ops arguments and rename it to xfs_bmap_read_buf. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: remove xfs_btree_reada_bufsChristoph Hellwig2024-02-223-42/+14
| | | | | | | | | | | | | | | | | | | | xfs_btree_reada_bufl just wraps xfs_btree_readahead and a agblock to daddr conversion. Just open code it's three callsites in the two callers (One of which isn't even btree related). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: remove xfs_btree_reada_buflChristoph Hellwig2024-02-222-35/+6
| | | | | | | | | | | | | | | | | | | | xfs_btree_reada_bufl just wraps xfs_btree_readahead and a fsblock to daddr conversion. Just open code it's two callsites in the only caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: factor out a __xfs_btree_check_lblock_hdr helperChristoph Hellwig2024-02-221-7/+23
| | | | | | | | | | | | | | | | This will allow sharing code with the in-memory block checking helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: rename btree helpers that depends on the block number representationChristoph Hellwig2024-02-227-59/+61
| | | | | | | | | | | | | | | | | | | | | | All these helpers hardcode fsblocks or agblocks and not just the pointer size. Rename them so that the names are still fitting when we add the long format in-memory blocks and adjust the checks when calling them to check the btree types and not just pointer length. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: consolidate btree block verificationChristoph Hellwig2024-02-223-58/+32
| | | | | | | | | | | | | | | | | | | | | | Add a __xfs_btree_check_block helper that can be called by the scrub code to validate a btree block of any form, and move the duplicate error handling code from xfs_btree_check_sblock and xfs_btree_check_lblock into xfs_btree_check_block and thus remove these two helpers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| * xfs: tighten up validation of root block in inode forksChristoph Hellwig2024-02-221-3/+13
| | | | | | | | | | | | | | | | | | Check that root blocks that sit in the inode fork and thus have a NULL bp don't have siblings. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>