summaryrefslogtreecommitdiffstats
path: root/fs/erofs
AgeCommit message (Collapse)AuthorLines
2026-04-15Merge tag 'mm-stable-2026-04-13-21-45' of ↵Linus Torvalds-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...
2026-04-13Merge tag 'erofs-for-7.1-rc1' of ↵Linus Torvalds-47/+77
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs updates from Gao Xiang: - Validate xattr h_shared_count to report -EFSCORRUPTED explicitly for crafted images - Verify metadata accesses for file-backed mounts via rw_verify_area() - Fix FS_IOC_GETFSLABEL to include the trailing NUL byte, consistent with ext4 and xfs - Properly handle 48-bit on-disk blocks/uniaddr for extra devices - Fix an index underflow in the LZ4 in-place decompression that can cause out-of-bounds accesses with crafted images - Minor fixes and cleanups * tag 'erofs-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: error out obviously illegal extents in advance erofs: clean up encoded map flags erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap() erofs: handle 48-bit blocks/uniaddr for extra devices erofs: include the trailing NUL in FS_IOC_GETFSLABEL erofs: ensure all folios are managed in erofs_try_to_free_all_cached_folios() erofs: verify metadata accesses for file-backed mounts erofs: harden h_shared_count in erofs_init_inode_xattrs()
2026-04-13Merge tag 'lsm-pr-20260410' of ↵Linus Torvalds-1/+9
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull LSM updates from Paul Moore: "We only have five patches in the LSM tree, but three of the five are for an important bugfix relating to overlayfs and the mmap() and mprotect() access controls for LSMs. Highlights below: - Fix problems with the mmap() and mprotect() LSM hooks on overlayfs As we are dealing with problems both in mmap() and mprotect() there are essentially two components to this fix, spread across three patches with all marked for stable. The simplest portion of the fix is the creation of a new LSM hook, security_mmap_backing_file(), that is used to enforce LSM mmap() access controls on backing files in the stacked/overlayfs case. The existing security_mmap_file() does not have visibility past the user file. You can see from the associated SELinux hook callback the code is fairly straightforward. The mprotect() fix is a bit more complicated as there is no way in the mprotect() code path to inspect both the user and backing files, and bolting on a second file reference to vm_area_struct wasn't really an option. The solution taken here adds a LSM security blob and associated hooks to the backing_file struct that LSMs can use to capture and store relevant information from the user file. While the necessary SELinux information is relatively small, a single u32, I expect other LSMs to require more than that, and a dedicated backing_file LSM blob provides a storage mechanism without negatively impacting other filesystems. I want to note that other LSMs beyond SELinux have been involved in the discussion of the fixes presented here and they are working on their own related changes using these new hooks, but due to other issues those patches will be coming at a later date. - Use kstrdup_const()/kfree_const() for securityfs symlink targets - Resolve a handful of kernel-doc warnings in cred.h" * tag 'lsm-pr-20260410' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: selinux: fix overlayfs mmap() and mprotect() access checks lsm: add backing_file LSM hooks fs: prepare for adding LSM blob to backing_file securityfs: use kstrdup_const() to manage symlink targets cred: fix kernel-doc warnings in cred.h
2026-04-10erofs: error out obviously illegal extents in advanceGao Xiang-10/+15
Detect some corrupted extent cases during metadata parsing rather than letting them result in harmless decompression failures later: - For full-reference compressed extents, the compressed size must not exceed the decompressed size, which is a strict on-disk layout constraint; - For plain (shifted/interlaced) extents, the decoded size must not exceed the encoded size, even accounting for partial decoding. Both ways work but it should be better to report illegal extents as metadata layout violations rather than deferring as decompression failure. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-10erofs: clean up encoded map flagsGao Xiang-31/+30
- Remove EROFS_MAP_ENCODED since it was always set together with EROFS_MAP_MAPPED for compressed extents and checked redundantly; - Replace the EROFS_MAP_FULL_MAPPED flag with the opposite EROFS_MAP_PARTIAL_MAPPED flag so that extents are implicitly fully mapped initially to simplify the logic; - Make fragment extents independent of EROFS_MAP_MAPPED since they are not directly allocated on disk; thus fragment extents are no longer twisted with mapped extents. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-10erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()Junrui Luo-0/+1
Some crafted images can have illegal (!partial_decoding && m_llen < m_plen) extents, and the LZ4 inplace decompression path can be wrongly hit, but it cannot handle (outpages < inpages) properly: "outpages - inpages" wraps to a large value and the subsequent rq->out[] access reads past the decompressed_pages array. However, such crafted cases can correctly result in a corruption report in the normal LZ4 non-inplace path. Let's add an additional check to fix this for backporting. Reproducible image (base64-encoded gzipped blob): H4sIAJGR12kCA+3SPUoDQRgG4MkmkkZk8QRbRFIIi9hbpEjrHQI5ghfwCN5BLCzTGtLbBI+g dilSJo1CnIm7GEXFxhT6PDDwfrs73/ywIQD/1ePD4r7Ou6ETsrq4mu7XcWfj++Pb58nJU/9i PNtbjhan04/9GtX4qVYc814WDqt6FaX5s+ZwXXeq52lndT6IuVvlblytLMvh4Gzwaf90nsvz 2DF/21+20T/ldgp5s1jXRaN4t/8izsy/OUB6e/Qa79r+JwAAAAAAAL52vQVuGQAAAP6+my1w ywAAAAAAAADwu14ATsEYtgBQAAA= $ mount -t erofs -o cache_strategy=disabled foo.erofs /mnt $ dd if=/mnt/data of=/dev/null bs=4096 count=1 Fixes: 598162d05080 ("erofs: support decompress big pcluster for lz4 backend") Reported-by: Yuhao Jiang <danisjiang@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo <moonafterrain@outlook.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-07erofs: handle 48-bit blocks/uniaddr for extra devicesZhan Xusheng-4/+8
erofs_init_device() only reads blocks_lo and uniaddr_lo from the on-disk device slot, ignoring blocks_hi and uniaddr_hi that were introduced alongside the 48-bit block addressing feature. For the primary device (dif0), erofs_read_superblock() already handles this correctly by combining blocks_lo with blocks_hi when 48-bit layout is enabled. But the same logic was not applied to extra devices. With a 48-bit EROFS image using extra devices whose uniaddr or blocks exceed 32-bit range, the truncated values cause erofs_map_dev() to compute wrong physical addresses, leading to silent data corruption. Fix this by reading blocks_hi and uniaddr_hi in erofs_init_device() when 48-bit layout is enabled, consistent with the primary device handling. Also fix the erofs_deviceslot on-disk definition where blocks_hi was incorrectly declared as __le32 instead of __le16. Fixes: 61ba89b57905 ("erofs: add 48-bit block addressing on-disk support") Suggested-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-05mm: add vma_desc_test_all() and use itLorenzo Stoakes (Oracle)-2/+1
erofs and zonefs are using vma_desc_test_any() twice to check whether all of VMA_SHARED_BIT and VMA_MAYWRITE_BIT are set, this is silly, so add vma_desc_test_all() to test all flags and update erofs and zonefs to use it. While we're here, update the helper function comments to be more consistent. Also add the same to the VMA test headers. Link: https://lkml.kernel.org/r/568c8f8d6a84ff64014f997517cba7a629f7eed6.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Babu Moger <babu.moger@amd.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chao Yu <chao@kernel.org> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Chunhai Guo <guochunhai@vivo.com> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hongbo Li <lihongbo22@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naohiro Aota <naohiro.aota@wdc.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sandeep Dhavale <dhavale@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Yue Hu <zbestahu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05mm: rename VMA flag helpers to be more readableLorenzo Stoakes (Oracle)-2/+2
Patch series "mm: vma flag tweaks". The ongoing work around introducing non-system word VMA flags has introduced a number of helper functions and macros to make life easier when working with these flags and to make conversions from the legacy use of VM_xxx flags more straightforward. This series improves these to reduce confusion as to what they do and to improve consistency and readability. Firstly the series renames vma_flags_test() to vma_flags_test_any() to make it abundantly clear that this function tests whether any of the flags are set (as opposed to vma_flags_test_all()). It then renames vma_desc_test_flags() to vma_desc_test_any() for the same reason. Note that we drop the 'flags' suffix here, as vma_desc_test_any_flags() would be cumbersome and 'test' implies a flag test. Similarly, we rename vma_test_all_flags() to vma_test_all() for consistency. Next, we have a couple of instances (erofs, zonefs) where we are now testing for vma_desc_test_any(desc, VMA_SHARED_BIT) && vma_desc_test_any(desc, VMA_MAYWRITE_BIT). This is silly, so this series introduces vma_desc_test_all() so these callers can instead invoke vma_desc_test_all(desc, VMA_SHARED_BIT, VMA_MAYWRITE_BIT). We then observe that quite a few instances of vma_flags_test_any() and vma_desc_test_any() are in fact only testing against a single flag. Using the _any() variant here is just confusing - 'any' of single item reads strangely and is liable to cause confusion. So in these instances the series reintroduces vma_flags_test() and vma_desc_test() as helpers which test against a single flag. The fact that vma_flags_t is a struct and that vma_flag_t utilises sparse to avoid confusion with vm_flags_t makes it impossible for a user to misuse these helpers without it getting flagged somewhere. The series also updates __mk_vma_flags() and functions invoked by it to explicitly mark them always inline to match expectation and to be consistent with other VMA flag helpers. It also renames vma_flag_set() to vma_flags_set_flag() (a function only used by __mk_vma_flags()) to be consistent with other VMA flag helpers. Finally it updates the VMA tests for each of these changes, and introduces explicit tests for vma_flags_test() and vma_desc_test() to assert that they behave as expected. This patch (of 6): On reflection, it's confusing to have vma_flags_test() and vma_desc_test_flags() test whether any comma-separated VMA flag bit is set, while also having vma_flags_test_all() and vma_test_all_flags() separately test whether all flags are set. Firstly, rename vma_flags_test() to vma_flags_test_any() to eliminate this confusion. Secondly, since the VMA descriptor flag functions are becoming rather cumbersome, prefer vma_desc_test*() to vma_desc_test_flags*(), and also rename vma_desc_test_flags() to vma_desc_test_any(). Finally, rename vma_test_all_flags() to vma_test_all() to keep the VMA-specific helper consistent with the VMA descriptor naming convention and to help avoid confusion vs. vma_flags_test_all(). While we're here, also update whitespace to be consistent in helper functions. Link: https://lkml.kernel.org/r/cover.1772704455.git.ljs@kernel.org Link: https://lkml.kernel.org/r/0f9cb3c511c478344fac0b3b3b0300bb95be95e9.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Suggested-by: Pedro Falcato <pfalcato@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Babu Moger <babu.moger@amd.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chao Yu <chao@kernel.org> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Chunhai Guo <guochunhai@vivo.com> Cc: Damien Le Maol <dlemoal@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hongbo Li <lihongbo22@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Johannes Thumshirn <jth@kernel.org> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naohiro Aota <naohiro.aota@wdc.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Sandeep Dhavale <dhavale@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Yue Hu <zbestahu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-03lsm: add backing_file LSM hooksPaul Moore-1/+9
Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2026-04-02erofs: include the trailing NUL in FS_IOC_GETFSLABELZhan Xusheng-1/+1
erofs_ioctl_get_volume_label() passes strlen(sbi->volume_name) as the length to copy_to_user(), which copies the label string without the trailing NUL byte. Since FS_IOC_GETFSLABEL callers expect a NUL-terminated string in the FSLABEL_MAX-sized buffer and may not pre-zero the buffer, this can cause userspace to read past the label into uninitialised stack memory. Fix this by using strlen() + 1 to include the NUL terminator, consistent with how ext4 and xfs implement FS_IOC_GETFSLABEL. Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Fixes: 1cf12c717741 ("erofs: Add support for FS_IOC_GETFSLABEL") Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Chunhai Guo <guochunhai@vivo.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-02erofs: ensure all folios are managed in erofs_try_to_free_all_cached_folios()Zhan Xusheng-2/+1
folio_trylock() in erofs_try_to_free_all_cached_folios() may successfully acquire the folio lock, but the subsequent check for erofs_folio_is_managed() can skip unlocking when the folio is not managed by EROFS. As Gao Xiang pointed out, this condition should not happen in practice because compressed_bvecs[] only holds valid cached folios at this point — any non-managed folio would have already been detached by z_erofs_cache_release_folio() under folio lock. Fix this by adding DBG_BUGON() to catch unexpected folios and ensure folio_unlock() is always called. Suggested-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Chunhai Guo <guochunhai@vivo.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-04-02erofs: verify metadata accesses for file-backed mountsGao Xiang-0/+14
For file-backed mounts, metadata is fetched via the page cache of backing inodes to avoid double caching and redundant copy ops out of RO uptodate folios, which is used by Android APEXes, ComposeFS, containerd. However, rw_verify_area() was missing prior to metadata accesses. Similar to vfs_iocb_iter_read(), fix this by: - Enabling fanotify pre-content hooks on metadata accesses; - security_file_permission() for security modules. Verified that fanotify pre-content hooks now works correctly. Fixes: fb176750266a ("erofs: add file-backed mount support") Acked-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Chunhai Guo <guochunhai@vivo.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-03-30erofs: harden h_shared_count in erofs_init_inode_xattrs()Utkal Singh-0/+8
`u8 h_shared_count` indicates the shared xattr count of an inode. It is read from the on-disk xattr ibody header, which should be corrupted if the size of the shared xattr array exceeds the space available in `xattr_isize`. It does not cause harmful consequence (e.g. crashes), since the image is already considered corrupted, it indeed results in the silent processing of garbage metadata. Let's harden it to report -EFSCORRUPTED earlier. Signed-off-by: Utkal Singh <singhutkal015@gmail.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-03-25erofs: fix .fadvise() for page cache sharingGao Xiang-2/+13
Currently, .fadvise() doesn't work well if page cache sharing is on since shared inodes belong to a pseudo fs generated with init_pseudo(), and sb->s_bdi is the default one &noop_backing_dev_info. Then, generic_fadvise() will just behave as a no-op if sb->s_bdi is &noop_backing_dev_info, but as the bdev fs (the bdev fs changes inode_to_bdi() instead), it's actually NOT a pure memfs. Let's generate a real bdi for erofs_ishare_mnt instead. Fixes: d86d7817c042 ("erofs: implement .fadvise for page cache share") Reviewed-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-03-25erofs: update the Kconfig descriptionGao Xiang-15/+30
Refine the description to better highlight its features and use cases. In addition, add instructions for building it as a module and clarify the compression option. Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-03-19erofs: add GFP_NOIO in the bio completion if neededJiucheng Xu-0/+3
The bio completion path in the process context (e.g. dm-verity) will directly call into decompression rather than trigger another workqueue context for minimal scheduling latencies, which can then call vm_map_ram() with GFP_KERNEL. Due to insufficient memory, vm_map_ram() may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios. Trimmed down the call stack, as follows: f2fs_submit_read_io submit_bio //bio_list is initialized. mmc_blk_mq_recovery z_erofs_endio vm_map_ram __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait //bio_list is non-NULL, hang!!! Use memalloc_noio_{save,restore}() to wrap up this path. Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Jiucheng Xu <jiucheng.xu@amlogic.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-03-17erofs: set fileio bio failed in short read caseSheng Yong-4/+2
For file-backed mount, IO requests are handled by vfs_iocb_iter_read(). However, it can be interrupted by SIGKILL, returning the number of bytes actually copied. Unused folios in bio are unexpectedly marked as uptodate. vfs_read filemap_read filemap_get_pages filemap_readahead erofs_fileio_readahead erofs_fileio_rq_submit vfs_iocb_iter_read filemap_read filemap_get_pages <= detect signal erofs_fileio_ki_complete <= set all folios uptodate This patch addresses this by setting short read bio with an error directly. Fixes: bc804a8d7e86 ("erofs: handle end of filesystem properly for file-backed mounts") Reported-by: chenguanyou <chenguanyou@xiaomi.com> Signed-off-by: Yunlei He <heyunlei@xiaomi.com> Signed-off-by: Sheng Yong <shengyong1@xiaomi.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-25erofs: fix interlaced plain identification for encoded extentsGao Xiang-4/+5
Only plain data whose start position and on-disk physical length are both aligned to the block size should be classified as interlaced plain extents. Otherwise, it must be treated as shifted plain extents. This issue was found by syzbot using a crafted compressed image containing plain extents with unaligned physical lengths, which can cause OOB read in z_erofs_transform_plain(). Reported-and-tested-by: syzbot+d988dc155e740d76a331@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/699d5714.050a0220.cdd3c.03e7.GAE@google.com Fixes: 1d191b4ca51d ("erofs: implement encoded extent metadata") Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-24erofs: remove more unnecessary #ifdefsFerry Meng-49/+36
Many #ifdefs can be replaced with IS_ENABLED() to improve code readability. No functional changes. Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-23erofs: allow sharing page cache with the same aops onlyHongbo Li-15/+22
Inode with identical data but different @aops cannot be mixed because the page cache is managed by different subsystems (e.g., @aops for compressed on-disk inodes cannot handle plain on-disk inodes). In this patch, we never allow inodes to share the page cache among plain, compressed, and fileio cases. When a shared inode is created, we initialize @aops that is the same as the initial real inode, and subsequent inodes cannot share the page cache if the inferred @aops differ from the corresponding shared inode. This is reasonable as a first step because, in typical use cases, if an inode is compressible, it will fall into compressed inodes across different filesystem images unless users use plain filesystems. However, in that cases, users will use plain filesystems all the time. Fixes: 5ef3208e3be5 ("erofs: introduce the page cache share feature") Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook-2/+1
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds-2/+1
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds-14/+14
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook-30/+29
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-18Merge tag 'mm-stable-2026-02-18-19-48' of ↵Linus Torvalds-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a couple of issues in the demotion code - pages were failed demotion and were finding themselves demoted into disallowed nodes (Bing Jiao) - "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare mapledtree race and performs a number of cleanups (Liam Howlett) - "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them" implements a lot of cleanups following on from the conversion of the VMA flags into a bitmap (Lorenzo Stoakes) - "support batch checking of references and unmapping for large folios" implements batching to greatly improve the performance of reclaiming clean file-backed large folios (Baolin Wang) - "selftests/mm: add memory failure selftests" does as claimed (Miaohe Lin) * tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits) mm/page_alloc: clear page->private in free_pages_prepare() selftests/mm: add memory failure dirty pagecache test selftests/mm: add memory failure clean pagecache test selftests/mm: add memory failure anonymous page test mm: rmap: support batched unmapping for file large folios arm64: mm: implement the architecture-specific clear_flush_young_ptes() arm64: mm: support batch clearing of the young flag for large folios arm64: mm: factor out the address and ptep alignment into a new helper mm: rmap: support batched checks of the references for large folios tools/testing/vma: add VMA userland tests for VMA flag functions tools/testing/vma: separate out vma_internal.h into logical headers tools/testing/vma: separate VMA userland tests into separate files mm: make vm_area_desc utilise vma_flags_t only mm: update all remaining mmap_prepare users to use vma_flags_t mm: update shmem_[kernel]_file_*() functions to use vma_flags_t mm: update secretmem to use VMA flags on mmap_prepare mm: update hugetlbfs to use VMA flags on mmap_prepare mm: add basic VMA flag operation helper functions tools: bitmap: add missing bitmap_[subset(), andnot()] mm: add mk_vma_flags() bitmap flag macro helper ...
2026-02-12mm: update all remaining mmap_prepare users to use vma_flags_tLorenzo Stoakes-2/+3
We will be shortly removing the vm_flags_t field from vm_area_desc so we need to update all mmap_prepare users to only use the dessc->vma_flags field. This patch achieves that and makes all ancillary changes required to make this possible. This lays the groundwork for future work to eliminate the use of vm_flags_t in vm_area_desc altogether and more broadly throughout the kernel. While we're here, we take the opportunity to replace VM_REMAP_FLAGS with VMA_REMAP_FLAGS, the vma_flags_t equivalent. No functional changes intended. Link: https://lkml.kernel.org/r/fb1f55323799f09fe6a36865b31550c9ec67c225.1769097829.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Damien Le Moal <dlemoal@kernel.org> [zonefs] Acked-by: "Darrick J. Wong" <djwong@kernel.org> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Yury Norov <ynorov@nvidia.com> Cc: Chris Mason <clm@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-09Merge tag 'erofs-for-7.0-rc1' of ↵Linus Torvalds-395/+773
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs updates from Gao Xiang: "In this cycle, inode page cache sharing among filesystems on the same machine is now supported, which is particularly useful for high-density hosts running tens of thousands of containers. In addition, we fully isolate the EROFS core on-disk format from other optional encoded layouts since the core on-disk part is designed to be simple, effective, and secure. Users can use the core format to build unique golden immutable images and import their filesystem trees directly from raw block devices via DMA, page-mapped DAX devices, and/or file-backed mounts without having to worry about unnecessary intrinsic consistency issues found in other generic filesystems by design. However, the full vision is still working in progress and will spend more time to achieve final goals. There are other improvements and bug fixes as usual, as listed below: - Support inode page cache sharing among filesystems - Formally separate optional encoded (aka compressed) inode layouts (and the implementations) from the EROFS core on-disk aligned plain format for future zero-trust security usage - Improve performance by caching the fact that an inode does not have a POSIX ACL - Improve LZ4 decompression error reporting - Enable LZMA by default and promote DEFLATE and Zstandard algorithms out of EXPERIMENTAL status - Switch to inode_set_cached_link() to cache symlink lengths - random bugfixes and minor cleanups" * tag 'erofs-for-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: (31 commits) erofs: fix UAF issue for file-backed mounts w/ directio option erofs: update compression algorithm status erofs: fix inline data read failure for ztailpacking pclusters erofs: avoid some unnecessary #ifdefs erofs: handle end of filesystem properly for file-backed mounts erofs: separate plain and compressed filesystems formally erofs: use inode_set_cached_link() erofs: mark inodes without acls in erofs_read_inode() erofs: implement .fadvise for page cache share erofs: support compressed inodes for page cache share erofs: support unencoded inodes for page cache share erofs: pass inode to trace_erofs_read_folio erofs: introduce the page cache share feature erofs: using domain_id in the safer way erofs: add erofs_inode_set_aops helper to set the aops erofs: support user-defined fingerprint name erofs: decouple `struct erofs_anon_fs_type` fs: Export alloc_empty_backing_file erofs: tidy up erofs_init_inode_xattrs() erofs: add missing documentation about `directio` mount option ...
2026-02-09Merge tag 'vfs-7.0-rc1.iomap' of ↵Linus Torvalds-21/+46
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs iomap updates from Christian Brauner: - Erofs page cache sharing preliminaries: Plumb a void *private parameter through iomap_read_folio() and iomap_readahead() into iomap_iter->private, matching iomap DIO. Erofs uses this to replace a bogus kmap_to_page() call, as preparatory work for page cache sharing. - Fix for invalid folio access: Fix an invalid folio access when a folio without iomap_folio_state is fully submitted to the IO helper — the helper may call folio_end_read() at any time, so ctx->cur_folio must be invalidated after full submission. * tag 'vfs-7.0-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iomap: fix invalid folio access after folio_end_read() erofs: hold read context in iomap_iter if needed iomap: stash iomap read ctx in the private field of iomap_iter
2026-02-09Merge tag 'vfs-7.0-rc1.fserror' of ↵Linus Torvalds-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs error reporting updates from Christian Brauner: "This contains the changes to support generic I/O error reporting. Filesystems currently have no standard mechanism for reporting metadata corruption and file I/O errors to userspace via fsnotify. Each filesystem (xfs, ext4, erofs, f2fs, etc.) privately defines EFSCORRUPTED, and error reporting to fanotify is inconsistent or absent entirely. This introduces a generic fserror infrastructure built around struct super_block that gives filesystems a standard way to queue metadata and file I/O error reports for delivery to fsnotify. Errors are queued via mempools and queue_work to avoid holding filesystem locks in the notification path; unmount waits for pending events to drain. A new super_operations::report_error callback lets filesystem drivers respond to file I/O errors themselves (to be used by an upcoming XFS self-healing patchset). On the uapi side, EFSCORRUPTED and EUCLEAN are promoted from private per-filesystem definitions to canonical errno.h values across all architectures" * tag 'vfs-7.0-rc1.fserror' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: ext4: convert to new fserror helpers xfs: translate fsdax media errors into file "data lost" errors when convenient xfs: report fs metadata errors via fsnotify iomap: report file I/O errors to the VFS fs: report filesystem and file I/O errors to fsnotify uapi: promote EFSCORRUPTED and EUCLEAN to errno.h
2026-02-06erofs: fix UAF issue for file-backed mounts w/ directio optionChao Yu-1/+6
[ 9.269940][ T3222] Call trace: [ 9.269948][ T3222] ext4_file_read_iter+0xac/0x108 [ 9.269979][ T3222] vfs_iocb_iter_read+0xac/0x198 [ 9.269993][ T3222] erofs_fileio_rq_submit+0x12c/0x180 [ 9.270008][ T3222] erofs_fileio_submit_bio+0x14/0x24 [ 9.270030][ T3222] z_erofs_runqueue+0x834/0x8ac [ 9.270054][ T3222] z_erofs_read_folio+0x120/0x220 [ 9.270083][ T3222] filemap_read_folio+0x60/0x120 [ 9.270102][ T3222] filemap_fault+0xcac/0x1060 [ 9.270119][ T3222] do_pte_missing+0x2d8/0x1554 [ 9.270131][ T3222] handle_mm_fault+0x5ec/0x70c [ 9.270142][ T3222] do_page_fault+0x178/0x88c [ 9.270167][ T3222] do_translation_fault+0x38/0x54 [ 9.270183][ T3222] do_mem_abort+0x54/0xac [ 9.270208][ T3222] el0_da+0x44/0x7c [ 9.270227][ T3222] el0t_64_sync_handler+0x5c/0xf4 [ 9.270253][ T3222] el0t_64_sync+0x1bc/0x1c0 EROFS may encounter above panic when enabling file-backed mount w/ directio mount option, the root cause is it may suffer UAF in below race condition: - z_erofs_read_folio wq s_dio_done_wq - z_erofs_runqueue - erofs_fileio_submit_bio - erofs_fileio_rq_submit - vfs_iocb_iter_read - ext4_file_read_iter - ext4_dio_read_iter - iomap_dio_rw : bio was submitted and return -EIOCBQUEUED - dio_aio_complete_work - dio_complete - dio->iocb->ki_complete (erofs_fileio_ki_complete()) - kfree(rq) : it frees iocb, iocb.ki_filp can be UAF in file_accessed(). - file_accessed : access NULL file point Introduce a reference count in struct erofs_fileio_rq, and initialize it as two, both erofs_fileio_ki_complete() and erofs_fileio_rq_submit() will decrease reference count, the last one decreasing the reference count to zero will free rq. Cc: stable@kernel.org Fixes: fb176750266a ("erofs: add file-backed mount support") Fixes: 6422cde1b0d5 ("erofs: use buffered I/O for file-backed mounts by default") Signed-off-by: Chao Yu <chao@kernel.org> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-05erofs: update compression algorithm statusGao Xiang-9/+3
The following changes are proposed in the upcoming Linux 7.0: - Enable LZMA support by default, as it's already in use by Fedora 42/43 and some Android vendors for minimal filesystem sizes; - Promote DEFLATE and Zstandard out of EXPERIMENTAL status, given that they have been landed and well-tested for over a year and are already ready for general use. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-05erofs: fix inline data read failure for ztailpacking pclustersGao Xiang-14/+16
Compressed folios for ztailpacking pclusters must be valid before adding these pclusters to I/O chains. Otherwise, z_erofs_decompress_pcluster() may assume they are already valid and then trigger a NULL pointer dereference. It is somewhat hard to reproduce because the inline data is in the same block as the tail of the compressed indexes, which are usually read just before. However, it may still happen if a fatal signal arrives while read_mapping_folio() is running, as shown below: erofs: (device dm-1): z_erofs_pcluster_begin: failed to get inline data -4 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ... pc : z_erofs_decompress_queue+0x4c8/0xa14 lr : z_erofs_decompress_queue+0x160/0xa14 sp : ffffffc08b3eb3a0 x29: ffffffc08b3eb570 x28: ffffffc08b3eb418 x27: 0000000000001000 x26: ffffff8086ebdbb8 x25: ffffff8086ebdbb8 x24: 0000000000000001 x23: 0000000000000008 x22: 00000000fffffffb x21: dead000000000700 x20: 00000000000015e7 x19: ffffff808babb400 x18: ffffffc089edc098 x17: 00000000c006287d x16: 00000000c006287d x15: 0000000000000004 x14: ffffff80ba8f8000 x13: 0000000000000004 x12: 00000006589a77c9 x11: 0000000000000015 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : ffffffffffffffe0 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: z_erofs_decompress_queue+0x4c8/0xa14 z_erofs_runqueue+0x908/0x97c z_erofs_read_folio+0x128/0x228 filemap_read_folio+0x68/0x128 filemap_get_pages+0x44c/0x8b4 filemap_read+0x12c/0x5b8 generic_file_read_iter+0x4c/0x15c do_iter_readv_writev+0x188/0x1e0 vfs_iter_read+0xac/0x1a4 backing_file_read_iter+0x170/0x34c ovl_read_iter+0xf0/0x140 vfs_read+0x28c/0x344 ksys_read+0x80/0xf0 __arm64_sys_read+0x24/0x34 invoke_syscall+0x60/0x114 el0_svc_common+0x88/0xe4 do_el0_svc+0x24/0x30 el0_svc+0x40/0xa8 el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1bc/0x1c0 Fix this by reading the inline data before allocating and adding the pclusters to the I/O chains. Fixes: cecf864d3d76 ("erofs: support inline data decompression") Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com> Reviewed-and-tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-03erofs: avoid some unnecessary #ifdefsFerry Meng-24/+14
They can either be removed or replaced with IS_ENABLED(). Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-03erofs: handle end of filesystem properly for file-backed mountsGao Xiang-12/+8
I/O requests beyond the end of the filesystem should be zeroed out, similar to loopback devices and that is what we expect. Fixes: ce63cb62d794 ("erofs: support unencoded inodes for fileio") Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-03erofs: separate plain and compressed filesystems formallyGao Xiang-42/+36
The EROFS on-disk format uses a tiny, plain metadata design that prioritizes performance and minimizes complex inconsistencies against common writable disk filesystems (almost all serious metadata inconsistency cannot happen in well-designed immutable filesystems like EROFS). EROFS deliberately avoids artificial design flaws to eliminate serious security risks from untrusted remote sources by design, although human-made implementation bugs can still happen sometimes. Currently, there is no strict check to prevent compressed inodes, especially LZ4-compressed inodes, from being read in plain filesystems. Starting with erofs-utils 1.0 and Linux 5.3, LZ4_0PADDING sb feature is automatically enabled for LZ4-compressed EROFS images to support in-place decompression. Furthermore, since Linux 5.4 LTS is no longer supported, we no longer need to handle ancient LZ4-compressed EROFS images generated by erofs-utils prior to 1.0. To formally distinguish different filesystem types for improved security: - Use the presence of LZ4_0PADDING or a non-zero `dsb->u1.lz4_max_distance` as a marker for compressed filesystems containing LZ4-compressed inodes only; - For other algorithms, use `dsb->u1.available_compr_algs` bitmap. Note: LZ4_0PADDING has been supported since Linux 5.4 (the first formal kernel version), so exposing it via sysfs is no longer necessary and is now deprecated (but remain it for five more years until 2031): `dsb->u1` has been strictly non-zero for all EROFS images containing compressed inodes starting with erofs-utils v1.3 and it is actually a much better marker for compressed filesystems. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-02-03erofs: use inode_set_cached_link()Gao Xiang-13/+21
Symlink lengths are now cached in in-memory inodes directly so that readlink can be sped up. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-28erofs: mark inodes without acls in erofs_read_inode()Gao Xiang-1/+26
Similar to commit 91ef18b567da ("ext4: mark inodes without acls in __ext4_iget()"), the ACL state won't be read when the file owner performs a lookup, and the RCU fast path for lookups won't work because the ACL state remains unknown. If there are no extended attributes, or if the xattr filter indicates that no ACL xattr is present, call cache_no_acl() directly. Reviewed-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: implement .fadvise for page cache shareHongzhen Luo-0/+7
This patch implements the .fadvise interface for page cache share. Similar to overlayfs, it drops those clean, unused pages through vfs_fadvise(). Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: support compressed inodes for page cache shareHongzhen Luo-16/+24
This patch adds page cache sharing functionality for compressed inodes. Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: support unencoded inodes for page cache shareHongbo Li-19/+81
This patch adds inode page cache sharing functionality for unencoded files. I conducted experiments in the container environment. Below is the memory usage for reading all files in two different minor versions of container images: +-------------------+------------------+-------------+---------------+ | Image | Page Cache Share | Memory (MB) | Memory | | | | | Reduction (%) | +-------------------+------------------+-------------+---------------+ | | No | 241 | - | | redis +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 163 | 33% | +-------------------+------------------+-------------+---------------+ | | No | 872 | - | | postgres +------------------+-------------+---------------+ | 16.1 & 16.2 | Yes | 630 | 28% | +-------------------+------------------+-------------+---------------+ | | No | 2771 | - | | tensorflow +------------------+-------------+---------------+ | 2.11.0 & 2.11.1 | Yes | 2340 | 16% | +-------------------+------------------+-------------+---------------+ | | No | 926 | - | | mysql +------------------+-------------+---------------+ | 8.0.11 & 8.0.12 | Yes | 735 | 21% | +-------------------+------------------+-------------+---------------+ | | No | 390 | - | | nginx +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 219 | 44% | +-------------------+------------------+-------------+---------------+ | tomcat | No | 924 | - | | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ | | Yes | 474 | 49% | +-------------------+------------------+-------------+---------------+ Additionally, the table below shows the runtime memory usage of the container: +-------------------+------------------+-------------+---------------+ | Image | Page Cache Share | Memory (MB) | Memory | | | | | Reduction (%) | +-------------------+------------------+-------------+---------------+ | | No | 35 | - | | redis +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 28 | 20% | +-------------------+------------------+-------------+---------------+ | | No | 149 | - | | postgres +------------------+-------------+---------------+ | 16.1 & 16.2 | Yes | 95 | 37% | +-------------------+------------------+-------------+---------------+ | | No | 1028 | - | | tensorflow +------------------+-------------+---------------+ | 2.11.0 & 2.11.1 | Yes | 930 | 10% | +-------------------+------------------+-------------+---------------+ | | No | 155 | - | | mysql +------------------+-------------+---------------+ | 8.0.11 & 8.0.12 | Yes | 132 | 15% | +-------------------+------------------+-------------+---------------+ | | No | 25 | - | | nginx +------------------+-------------+---------------+ | 7.2.4 & 7.2.5 | Yes | 20 | 20% | +-------------------+------------------+-------------+---------------+ | tomcat | No | 186 | - | | 10.1.25 & 10.1.26 +------------------+-------------+---------------+ | | Yes | 98 | 48% | +-------------------+------------------+-------------+---------------+ Co-developed-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: pass inode to trace_erofs_read_folioHongbo Li-6/+4
The trace_erofs_read_folio accesses inode information through folio, but this method fails if the real inode is not associated with the folio(such as in the upcoming page cache sharing case). Therefore, we pass the real inode to it so that the inode information can be printed out in that case. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: introduce the page cache share featureHongzhen Luo-2/+296
Currently, reading files with different paths (or names) but the same content will consume multiple copies of the page cache, even if the content of these page caches is the same. For example, reading identical files (e.g., *.so files) from two different minor versions of container images will cost multiple copies of the same page cache, since different containers have different mount points. Therefore, sharing the page cache for files with the same content can save memory. This introduces the page cache share feature in erofs. It allocate a shared inode and use its page cache as shared. Reads for files with identical content will ultimately be routed to the page cache of the shared inode. In this way, a single page cache satisfies multiple read requests for different files with the same contents. We introduce new mount option `inode_share` to enable the page sharing mode during mounting. This option is used in conjunction with `domain_id` to share the page cache within the same trusted domain. Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: using domain_id in the safer wayHongbo Li-8/+6
Either the existing fscache usecase or the upcoming page cache sharing case, the `domain_id` should be protected as sensitive information, so we use the safer helpers to allocate, free and display domain_id. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: add erofs_inode_set_aops helper to set the aopsHongbo Li-23/+23
Add erofs_inode_set_aops helper to set the inode->i_mapping->a_ops and use IS_ENABLED to make it cleaner. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: support user-defined fingerprint nameHongzhen Luo-2/+36
When creating the EROFS image, users can specify the fingerprint name. This is to prepare for the upcoming inode page cache share. Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: decouple `struct erofs_anon_fs_type`Gao Xiang-13/+16
- Move the `struct erofs_anon_fs_type` to super.c and expose it in preparation for the upcoming page cache share feature; - Remove the `.owner` field, as they are all internal mounts and fully managed by EROFS. Retaining `.owner` would unnecessarily increment module reference counts, preventing the EROFS kernel module from being unloaded. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23Merge branch 'vfs-7.0.iomap' of ↵Gao Xiang-21/+46
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull 'vfs-7.0.iomap' to allow iomap page cache users to set `iomap_iter::private` for the upcoming page cache sharing support. It also includes a patch to avoid triggering inline data reads for the FIEMAP operation. Signed-off-by: Gao Xiang <xiang@kernel.org>
2026-01-23erofs: tidy up erofs_init_inode_xattrs()Gao Xiang-37/+25
Mainly get rid of the use of `struct erofs_xattr_iter`, as it is no longer needed now that meta buffers are used. This also simplifies the code and uses an early return when there are no xattrs. Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-01-23erofs: tidy up synchronous decompressionGao Xiang-29/+16
- Get rid of `sbi->opt.max_sync_decompress_pages` since it's fixed as 3 all the time; - Add Z_EROFS_MAX_SYNC_DECOMPRESS_BYTES in bytes instead of in pages, since for non-4K pages, 3-page limitation makes no sense; - Move `sync_decompress` to sbi to avoid unexpected remount impact; - Fold z_erofs_is_sync_decompress() into its caller; - Better description of sysfs entry `sync_decompress`. Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>