aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/lib/test_xarray.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-0/+93
Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-05XArray: set the marks correctly when splitting an entryMatthew Wilcox (Oracle)1-1/+13
If we created a new node to replace an entry which had search marks set, we were setting the search mark on every entry in that node. That works fine when we're splitting to order 0, but when splitting to a larger order, we must not set the search marks on the sibling entries. Link: https://lkml.kernel.org/r/20240501153120.4094530-1-willy@infradead.org Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/ZjFGCOYk3FK_zVy3@bombadil.infradead.org Tested-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05lib/test_xarray.c: fix error assumptions on check_xa_multi_store_adv_add()Luis Chamberlain1-4/+9
While testing lib/test_xarray in userspace I've noticed we can fail with: make -C tools/testing/radix-tree ./tools/testing/radix-tree/xarray BUG at check_xa_multi_store_adv_add:749 xarray: 0x55905fb21a00x head 0x55905fa1d8e0x flags 0 marks 0 0 0 0: 0x55905fa1d8e0x xarray: ../../../lib/test_xarray.c:749: check_xa_multi_store_adv_add: Assertion `0' failed. Aborted We get a failure with a BUG_ON(), and that is because we actually can fail due to -ENOMEM, the check in xas_nomem() will fix this for us so it makes no sense to expect no failure inside the loop. So modify the check and since this is also useful for instructional purposes clarify the situation. The check for XA_BUG_ON(xa, xa_load(xa, index) != p) is already done at the end of the loop so just remove the bogus on inside the loop. With this we now pass the test in both kernel and userspace: In userspace: ./tools/testing/radix-tree/xarray XArray: 149092856 of 149092856 tests passed In kernel space: XArray: 148257077 of 148257077 tests passed Link: https://lkml.kernel.org/r/20240423192221.301095-3-mcgrof@kernel.org Fixes: a60cc288a1a2 ("test_xarray: add tests for advanced multi-index use") Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm/filemap: optimize filemap folio addingKairui Song1-0/+59
Instead of doing multiple tree walks, do one optimism range check with lock hold, and exit if raced with another insertion. If a shadow exists, check it with a new xas_get_order helper before releasing the lock to avoid redundant tree walks for getting its order. Drop the lock and do the allocation only if a split is needed. In the best case, it only need to walk the tree once. If it needs to alloc and split, 3 walks are issued (One for first ranged conflict check and order retrieving, one for the second check after allocation, one for the insert after split). Testing with 4K pages, in an 8G cgroup, with 16G brd as block device: echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap --rw=randread --time_based \ --ramp_time=30s --runtime=5m --group_reporting Before: bw ( MiB/s): min= 1027, max= 3520, per=100.00%, avg=2445.02, stdev=18.90, samples=8691 iops : min=263001, max=901288, avg=625924.36, stdev=4837.28, samples=8691 After (+7.3%): bw ( MiB/s): min= 493, max= 3947, per=100.00%, avg=2625.56, stdev=25.74, samples=8651 iops : min=126454, max=1010681, avg=672142.61, stdev=6590.48, samples=8651 Test result with THP (do a THP randread then switch to 4K page in hope it issues a lot of splitting): echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap -thp=1 --readonly \ --rw=randread --time_based --ramp_time=30s --runtime=10m \ --group_reporting fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap \ --rw=randread --time_based --runtime=5s --group_reporting Before: bw ( KiB/s): min= 4141, max=14202, per=100.00%, avg=7935.51, stdev=96.85, samples=18976 iops : min= 1029, max= 3548, avg=1979.52, stdev=24.23, samples=18976ยท READ: bw=4545B/s (4545B/s), 4545B/s-4545B/s (4545B/s-4545B/s), io=64.0KiB (65.5kB), run=14419-14419msec After (+12.5%): bw ( KiB/s): min= 4611, max=15370, per=100.00%, avg=8928.74, stdev=105.17, samples=19146 iops : min= 1151, max= 3842, avg=2231.27, stdev=26.29, samples=19146 READ: bw=4635B/s (4635B/s), 4635B/s-4635B/s (4635B/s-4635B/s), io=64.0KiB (65.5kB), run=14137-14137msec The performance is better for both 4K (+7.5%) and THP (+12.5%) cached read. Link: https://lkml.kernel.org/r/20240415171857.19244-5-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25lib/xarray: introduce a new helper xas_get_orderKairui Song1-0/+34
It can be used after xas_load to check the order of loaded entries. Compared to xa_get_order, it saves an XA_STATE and avoid a rewalk. Added new test for xas_get_order, to make the test work, we have to export xas_get_order with EXPORT_SYMBOL_GPL. Also fix a sparse warning by checking the slot value with xa_entry instead of accessing it directly, as suggested by Matthew Wilcox. [kasong@tencent.com: simplify comment, sparse warning fix, per Matthew Wilcox] Link: https://lkml.kernel.org/r/20240416071722.45997-4-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20240415171857.19244-4-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22XArray: add cmpxchg order testDaniel Gomez1-0/+54
XArray multi-index entries do not keep track of the order stored once the entry is being marked as used with cmpxchg (conditionally replaced with NULL). Add a test to check the order is actually lost. The test also verifies the order and entries for all the tied indexes before and after the NULL replacement with xa_cmpxchg. Add another entry at 1 << order that keeps the node around and the order information for the NULL-entry after xa_cmpxchg. Link: https://lkml.kernel.org/r/20240131225125.1370598-3-mcgrof@kernel.org Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22test_xarray: add tests for advanced multi-index useLuis Chamberlain1-0/+176
Patch series "test_xarray: advanced API multi-index tests", v2. This is a respin of the test_xarray multi-index tests [0] which use and demonstrate the advanced API which is used by the page cache. This should let folks more easily follow how we use multi-index to support for example a min order later in the page cache. It also lets us grow the selftests to mimic more of what we do in the page cache. This patch (of 2): The multi index selftests are great but they don't replicate how we deal with the page cache exactly, which makes it a bit hard to follow as the page cache uses the advanced API. Add tests which use the advanced API, mimicking what we do in the page cache, while at it, extend the example to do what is needed for min order support. [mcgrof@kernel.org: fix soft lockup for advanced-api tests] Link: https://lkml.kernel.org/r/20240216194329.840555-1-mcgrof@kernel.org [akpm@linux-foundation.org: s/i/loops/, make non-static] [akpm@linux-foundation.org: restore static storage for loop counter] Link: https://lkml.kernel.org/r/20240131225125.1370598-1-mcgrof@kernel.org Link: https://lkml.kernel.org/r/20240131225125.1370598-2-mcgrof@kernel.org Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: Daniel Gomez <da.gomez@samsung.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-03-28XArray: Fix xas_create_range() when multi-order entry presentMatthew Wilcox (Oracle)1-0/+22
If there is already an entry present that is of order >= XA_CHUNK_SHIFT when we call xas_create_range(), xas_create_range() will misinterpret that entry as a node and dereference xa_node->parent, generally leading to a crash that looks something like this: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 32 Comm: khugepaged Not tainted 5.17.0-rc8-syzkaller-00003-g56e337f2cf13 #0 RIP: 0010:xa_parent_locked include/linux/xarray.h:1207 [inline] RIP: 0010:xas_create_range+0x2d9/0x6e0 lib/xarray.c:725 It's deterministically reproducable once you know what the problem is, but producing it in a live kernel requires khugepaged to hit a race. While the problem has been present since xas_create_range() was introduced, I'm not aware of a way to hit it before the page cache was converted to use multi-index entries. Fixes: 6b24ca4a1a8d ("mm: Use multi-index entries in the page cache") Reported-by: syzbot+0d2b0bf32ca5cfd09f2e@syzkaller.appspotmail.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2021-03-30XArray: Fix splitting to non-zero ordersMatthew Wilcox (Oracle)1-12/+14
Splitting an order-4 entry into order-2 entries would leave the array containing pointers to 000040008000c000 instead of 000044448888cccc. This is a one-character fix, but enhance the test suite to check this case. Reported-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-20Merge tag 'xarray-5.9' of git://git.infradead.org/users/willy/xarrayLinus Torvalds1-6/+26
Pull XArray updates from Matthew Wilcox: - Fix the test suite after introduction of the local_lock - Fix a bug in the IDA spotted by Coverity - Change the API that allows the workingset code to delete a node - Fix xas_reload() when dealing with entries that occupy multiple indices - Add a few more tests to the test suite - Fix an unsigned int being shifted into an unsigned long * tag 'xarray-5.9' of git://git.infradead.org/users/willy/xarray: XArray: Fix xas_create_range for ranges above 4 billion radix-tree: fix the comment of radix_tree_next_slot() XArray: Fix xas_reload for multi-index entries XArray: Add private interface for workingset node deletion XArray: Fix xas_for_each_conflict documentation XArray: Test marked multiorder iterations XArray: Test two more things about xa_cmpxchg ida: Free allocated bitmap in error path radix tree test suite: Fix compilation
2020-10-16XArray: add xas_splitMatthew Wilcox (Oracle)1-0/+44
In order to use multi-index entries for huge pages in the page cache, we need to be able to split a multi-index entry (eg if a file is truncated in the middle of a huge page entry). This version does not support splitting more than one level of the tree at a time. This is an acceptable limitation for the page cache as we do not expect to support order-12 pages in the near future. [akpm@linux-foundation.org: export xas_split_alloc() to modules] [willy@infradead.org: fix xarray split] Link: https://lkml.kernel.org/r/20200910175450.GV6583@casper.infradead.org [willy@infradead.org: fix xarray] Link: https://lkml.kernel.org/r/20201001233943.GW20115@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Qian Cai <cai@lca.pw> Cc: Song Liu <songliubraving@fb.com> Link: https://lkml.kernel.org/r/20200903183029.14930-3-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16XArray: add xa_get_orderMatthew Wilcox (Oracle)1-0/+21
Patch series "Fix read-only THP for non-tmpfs filesystems". As described more verbosely in the [3/3] changelog, we can inadvertently put an order-0 page in the page cache which occupies 512 consecutive entries. Users are running into this if they enable the READ_ONLY_THP_FOR_FS config option; see https://bugzilla.kernel.org/show_bug.cgi?id=206569 and Qian Cai has also reported it here: https://lore.kernel.org/lkml/20200616013309.GB815@lca.pw/ This is a rather intrusive way of fixing the problem, but has the advantage that I've actually been testing it with the THP patches, which means that it sees far more use than it does upstream -- indeed, Song has been entirely unable to reproduce it. It also has the advantage that it removes a few patches from my gargantuan backlog of THP patches. This patch (of 3): This function returns the order of the entry at the index. We need this because there isn't space in the shadow entry to encode its order. [akpm@linux-foundation.org: export xa_get_order to modules] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Qian Cai <cai@lca.pw> Cc: Song Liu <songliubraving@fb.com> Link: https://lkml.kernel.org/r/20200903183029.14930-1-willy@infradead.org Link: https://lkml.kernel.org/r/20200903183029.14930-2-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13XArray: Add private interface for workingset node deletionMatthew Wilcox (Oracle)1-6/+1
Move the tricky bits of dealing with the XArray from the workingset code to the XArray. Make it clear in the documentation that this is a private interface, and only export it for the benefit of the test suite. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-08XArray: Test marked multiorder iterationsMatthew Wilcox (Oracle)1-0/+22
Demonstrate that starting a marked iteration partway through a marked multi-order entry works. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-10-07XArray: Test two more things about xa_cmpxchgMatthew Wilcox (Oracle)1-0/+3
1. If we xa_cmpxchg() an entry in, it marks the index as not free. 2. If we xa_cmpxchg() NULL in, it marks the index as free. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2020-01-31XArray: Fix xas_pause for large multi-index entriesMatthew Wilcox (Oracle)1-0/+37
Inspired by the recent Coverity report, I looked for other places where the offset wasn't being converted to an unsigned long before being shifted, and I found one in xas_pause() when the entry being paused is of order >32. Fixes: b803b42823d0 ("xarray: Add XArray iterators") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org
2020-01-31XArray: Fix xa_find_next for large multi-index entriesMatthew Wilcox (Oracle)1-0/+18
Coverity pointed out that xas_sibling() was shifting xa_offset without promoting it to an unsigned long first, so the shift could cause an overflow and we'd get the wrong answer. The fix is obvious, and the new test-case provokes UBSAN to report an error: runtime error: shift exponent 60 is too large for 32-bit type 'int' Fixes: 19c30f4dd092 ("XArray: Fix xa_find_after with multi-index entries") Reported-by: Bjorn Helgaas <bhelgaas@google.com> Reported-by: Kees Cook <keescook@chromium.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org
2020-01-17XArray: Fix xas_find returning too many entriesMatthew Wilcox (Oracle)1-0/+5
If you call xas_find() with the initial index > max, it should have returned NULL but was returning the entry at index. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org
2020-01-17XArray: Fix xa_find_after with multi-index entriesMatthew Wilcox (Oracle)1-13/+19
If the entry is of an order which is a multiple of XA_CHUNK_SIZE, the current detection of sibling entries does not work. Factor out an xas_sibling() function to make xa_find_after() a little more understandable, and write a new implementation that doesn't suffer from the same bug. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org
2020-01-17XArray: Fix infinite loop with entry at ULONG_MAXMatthew Wilcox (Oracle)1-0/+17
If there is an entry at ULONG_MAX, xa_for_each() will overflow the 'index + 1' in xa_find_after() and wrap around to 0. Catch this case and terminate the loop by returning NULL. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@vger.kernel.org
2019-11-08XArray: Fix xas_pause at ULONG_MAXMatthew Wilcox (Oracle)1-0/+22
If we were unlucky enough to call xas_pause() when the index was at ULONG_MAX (or a multi-slot entry which ends at ULONG_MAX), we would wrap the index back around to 0 and restart the iteration from the beginning. Use the XAS_BOUNDS state to indicate that we should just stop the iteration. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2019-07-01XArray: Fix xas_next() with a single entry at 0Matthew Wilcox (Oracle)1-0/+24
If there is only a single entry at 0, the first time we call xas_next(), we return the entry. Unfortunately, all subsequent times we call xas_next(), we also return the entry at 0 instead of noticing that the xa_index is now greater than zero. This broke find_get_pages_contig(). Fixes: 64d3e9a9e0cc ("xarray: Step through an XArray") Reported-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2019-06-02XArray tests: Add check_insertMatthew Wilcox1-0/+38
A simple test which just checks that inserting an entry into an empty array succeeds. Try various different interesting indices. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-21XArray: Fix xa_reserve for 2-byte aligned entriesMatthew Wilcox1-0/+10
If we reserve index 0, the next entry to be stored there might be 2-byte aligned. That means we have to create the root xa_node at the time of reserving the initial entry. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-21XArray: Fix xa_erase of 2-byte aligned entriesMatthew Wilcox1-1/+15
xas_store() was interpreting the entry it found in the array as a node entry if the bottom two bits had value 2. That's only true if either the entry is in the root node or in a non-leaf node. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-20XArray: Fix xa_release in allocating arraysMatthew Wilcox1-4/+24
xa_cmpxchg() was a little too magic in turning ZERO entries into NULL, and would leave the entry set to the ZERO entry instead of releasing it for future use. After careful review of existing users of xa_cmpxchg(), change the semantics so that it does not translate either incoming argument from NULL into ZERO entries. Add several tests to the test-suite to make sure this problem doesn't come back. Reported-by: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-09XArray: Mark xa_insert and xa_reserve as must_checkMatthew Wilcox1-5/+5
If the user doesn't care about the return value from xa_insert(), then they should be using xa_store() instead. The point of xa_reserve() is to get the return value early before taking another lock, so this should also be __must_check. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-06XArray: Add cyclic allocationMatthew Wilcox1-0/+53
This differs slightly from the IDR equivalent in five ways. 1. It can allocate up to UINT_MAX instead of being limited to INT_MAX, like xa_alloc(). Also like xa_alloc(), it will write to the 'id' pointer before placing the entry in the XArray. 2. The 'next' cursor is allocated separately from the XArray instead of being part of the IDR. This saves memory for all the users which do not use the cyclic allocation API and suits some users better. 3. It returns -EBUSY instead of -ENOSPC. 4. It will attempt to wrap back to the minimum value on memory allocation failure as well as on an -EBUSY error, assuming that a user would rather allocate a small ID than suffer an ID allocation failure. 5. It reports whether it has wrapped, which is important to some users. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-06XArray: Redesign xa_alloc APIMatthew Wilcox1-16/+70
It was too easy to forget to initialise the start index. Add an xa_limit data structure which can be used to pass min & max, and define a couple of special values for common cases. Also add some more tests cribbed from the IDR test suite. Change the return value from -ENOSPC to -EBUSY to match xa_insert(). Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-06XArray: Add support for 1s-based allocationMatthew Wilcox1-33/+55
A lot of places want to allocate IDs starting at 1 instead of 0. While the xa_alloc() API supports this, it's not very efficient if lots of IDs are allocated, due to having to walk down to the bottom of the tree to see if ID 1 is available, then all the way over to the next non-allocated ID. This method marks ID 0 as being occupied which wastes one slot in the XArray, but preserves xa_empty() as working. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-06XArray: Change xa_insert to return -EBUSYMatthew Wilcox1-2/+2
Userspace translates EEXIST to "File exists" which isn't a very good error message for the problem. "Device or resource busy" is a better indication of what went wrong. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-02-04XArray tests: RCU lock prohibits GFP_KERNELMatthew Wilcox1-0/+3
Drop and reacquire the RCU read lock while using GFP_KERNEL. Reported-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-01-14XArray tests: Check mark 2 gets squashedMatthew Wilcox1-3/+3
We do not currently check that the loop in xas_squash_marks() doesn't have an off-by-one error in it. It didn't, but a patch which introduced an off-by-one error wasn't caught by any existing test. Switch the roles of XA_MARK_1 and XA_MARK_2 to catch that bug. Reported-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-01-06XArray: Honour reserved entries in xa_insertMatthew Wilcox1-3/+5
xa_insert() should treat reserved entries as occupied, not as available. Also, it should treat requests to insert a NULL pointer as a request to reserve the slot. Add xa_insert_bh() and xa_insert_irq() for completeness. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-01-06XArray: Permit storing 2-byte-aligned pointersMatthew Wilcox1-0/+30
On m68k, statically allocated pointers may only be two-byte aligned. This clashes with the XArray's method for tagging internal pointers. Permit storing these pointers in single slots (ie not in multislots). Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-01-06XArray: Change xa_for_each iteratorMatthew Wilcox1-6/+5
There were three problems with this API: 1. It took too many arguments; almost all users wanted to iterate over every element in the array rather than a subset. 2. It required that 'index' be initialised before use, and there's no realistic way to make GCC catch that. 3. 'index' and 'entry' were the opposite way round from every other member of the XArray APIs. So split it into three different APIs: xa_for_each(xa, index, entry) xa_for_each_start(xa, index, entry, start) xa_for_each_marked(xa, index, entry, filter) Signed-off-by: Matthew Wilcox <willy@infradead.org>
2019-01-06XArray tests: Add RCU lockingMatthew Wilcox1-0/+2
0day picked up that I'd forgotten to add locking to this new test. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-13XArray: Fix xa_alloc when id exceeds maxMatthew Wilcox1-0/+33
Specifying a starting ID greater than the maximum ID isn't something attempted very often, but it should fail. It was succeeding due to xas_find_marked() returning the wrong error state, so add tests for both xa_alloc() and xas_find_marked(). Fixes: b803b42823d0 ("xarray: Add XArray iterators") Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-06XArray tests: Check iterating over multiorder entriesMatthew Wilcox1-0/+31
There was no bug here, but there was no test coverage for this scenario. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-06XArray tests: Handle larger indices more elegantlyMatthew Wilcox1-43/+48
xa_mk_value() only handles values up to LONG_MAX. I successfully hid that inside xa_store_index() and xa_erase_index(), but it turned out I also needed it for testing xa_alloc() on 32-bit machines. So extract xa_mk_index() from the above two functions, and convert the non-constant users of xa_mk_value() to xa_mk_index(). Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-11-19XArray tests: Add missing lockingMatthew Wilcox1-0/+10
Lockdep caught me being sloppy in the test suite and failing to lock the XArray appropriately. Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-11-16XArray tests: Correct some 64-bit assumptionsMatthew Wilcox1-2/+2
The test-suite caught these two mistakes when compiled for 32-bit. I had only been running the test-suite in 64-bit mode. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-11-05XArray: Regularise xa_reserveMatthew Wilcox1-0/+6
The xa_reserve() function was a little unusual in that it attempted to be callable for all kinds of locking scenarios. Make it look like the other APIs with __xa_reserve, xa_reserve_bh and xa_reserve_irq variants. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-11-05XArray: Fix xa_for_each with a single element at 0Matthew Wilcox1-1/+29
The following sequence of calls would result in an infinite loop in xa_find_after(): xa_store(xa, 0, x, GFP_KERNEL); index = 0; xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) { } xa_find_after() was confusing the situation where we found no entry in the tree with finding a multiorder entry, so it would look for the successor entry forever. Just check for this case explicitly. Includes a few new checks in the test suite to be sure this doesn't reappear. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21xarray: Add range store functionalityMatthew Wilcox1-0/+34
This version of xa_store_range() really only supports load and store. Our only user only needs basic load and store functionality, so there's no need to do the extra work to support marking and overlapping stores correctly yet. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21xarray: Move multiorder_check to in-kernel testsMatthew Wilcox1-0/+44
This version is a little less thorough in order to be a little quicker, but tests the important edge cases. Also test adding a multiorder entry at a non-canonical index, and erasing it. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21xarray: Move multiorder_shrink to kernel testsMatthew Wilcox1-0/+37
Test this functionality inside the kernel as well as in userspace. Also remove insert_bug() as there's no comparable thing to test in the XArray code. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21xarray: Move multiorder account test in-kernelMatthew Wilcox1-0/+32
Move this test to the in-kernel test suite, and enhance it to test several different orders. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21radix tree: Remove radix_tree_clear_tagsMatthew Wilcox1-0/+40
The page cache was the only user of this interface and it has now been converted to the XArray. Transform the test into a test of xas_init_marks(). Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-10-21shmem: Convert find_swap_entry to XArrayMatthew Wilcox1-0/+56
This is a 1:1 conversion. The major part of this patch is converting the test framework from userspace to kernel space and mirroring the algorithm now used in find_swap_entry(). Signed-off-by: Matthew Wilcox <willy@infradead.org>