kernel.git/fs/ext4/inode.c, branch linux-6.15.y

ext4: Make sure BH_New bit is cleared in ->write_end handler

2025-08-15T10:16:46Z

[ Upstream commit 91b8ca8b26729b729dda8a4eddb9aceaea706f37 ] Currently we clear BH_New bit in case of error and also in the standard ext4_write_end() handler (in block_commit_write()). However ext4_journalled_write_end() misses this clearing and thus we are leaving stale BH_New bits behind. Generally ext4_block_write_begin() clears these bits before any harm can be done but in case blocksize < pagesize and we hit some error when processing a page with these stale bits, we'll try to zero buffers with these stale BH_New bits and jbd2 will complain (as buffers were not prepared for writing in this transaction). Fix the problem by clearing BH_New bits in ext4_journalled_write_end() and WARN if ext4_block_write_begin() sees stale BH_New bits. Reported-by: Baolin Liu Reported-by: Zhi Long Fixes: 3910b513fcdf ("ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffers") Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250709084831.23876-2-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: only dirty folios when data journaling regular files

2025-06-27T10:13:04Z

commit e26268ff1dcae5662c1b96c35f18cfa6ab73d9de upstream. fstest generic/388 occasionally reproduces a crash that looks as follows: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: ext4_block_zero_page_range+0x30c/0x380 [ext4] ext4_truncate+0x436/0x440 [ext4] ext4_process_orphan+0x5d/0x110 [ext4] ext4_orphan_cleanup+0x124/0x4f0 [ext4] ext4_fill_super+0x262d/0x3110 [ext4] get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x26/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4ed/0x6b0 do_syscall_64+0x82/0x170 ... This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash. To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly. Fixes: d84c9ebdac1e ("ext4: Mark pages with journalled data dirty") Signed-off-by: Brian Foster Link: https://patch.msgid.link/20250516173800.175577-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: ensure i_size is smaller than maxbytes

2025-06-27T10:13:03Z

commit 1a77a028a392fab66dd637cdfac3f888450d00af upstream. The inode i_size cannot be larger than maxbytes, check it while loading inode from the disk. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: fix incorrect punch max_end

2025-06-27T10:13:03Z

commit 29ec9bed2395061350249ae356fb300dd82a78e7 upstream. For the extents based inodes, the maxbytes should be sb->s_maxbytes instead of sbi->s_bitmap_maxbytes. Additionally, for the calculation of max_end, the -sb->s_blocksize operation is necessary only for indirect-block based inodes. Correct the maxbytes and max_end value to correct the behavior of punch hole. Fixes: 2da376228a24 ("ext4: limit length to bitmap_maxbytes - blocksize in punch_hole") Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: fix out of bounds punch offset

2025-06-27T10:13:03Z

commit b5e58bcd79625423487fa3ecba8e8411b5396327 upstream. Punching a hole with a start offset that exceeds max_end is not permitted and will result in a negative length in the truncate_inode_partial_folio() function while truncating the page cache, potentially leading to undesirable consequences. A simple reproducer: truncate -s 9895604649994 /mnt/foo xfs_io -c "pwrite 8796093022208 4096" /mnt/foo xfs_io -c "fpunch 8796093022213 25769803777" /mnt/foo kernel BUG at include/linux/highmem.h:275! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 710 Comm: xfs_io Not tainted 6.15.0-rc3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:zero_user_segments.constprop.0+0xd7/0x110 RSP: 0018:ffffc90001cf3b38 EFLAGS: 00010287 RAX: 0000000000000005 RBX: ffffea0001485e40 RCX: 0000000000001000 RDX: 000000000040b000 RSI: 0000000000000005 RDI: 000000000040b000 RBP: 000000000040affb R08: ffff888000000000 R09: ffffea0000000000 R10: 0000000000000003 R11: 00000000fffc7fc5 R12: 0000000000000005 R13: 000000000040affb R14: ffffea0001485e40 R15: ffff888031cd3000 FS: 00007f4f63d0b780(0000) GS:ffff8880d337d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000001ae0b038 CR3: 00000000536aa000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: truncate_inode_partial_folio+0x3dd/0x620 truncate_inode_pages_range+0x226/0x720 ? bdev_getblk+0x52/0x3e0 ? ext4_get_group_desc+0x78/0x150 ? crc32c_arch+0xfd/0x180 ? __ext4_get_inode_loc+0x18c/0x840 ? ext4_inode_csum+0x117/0x160 ? jbd2_journal_dirty_metadata+0x61/0x390 ? __ext4_handle_dirty_metadata+0xa0/0x2b0 ? kmem_cache_free+0x90/0x5a0 ? jbd2_journal_stop+0x1d5/0x550 ? __ext4_journal_stop+0x49/0x100 truncate_pagecache_range+0x50/0x80 ext4_truncate_page_cache_block_range+0x57/0x3a0 ext4_punch_hole+0x1fe/0x670 ext4_fallocate+0x792/0x17d0 ? __count_memcg_events+0x175/0x2a0 vfs_fallocate+0x121/0x560 ksys_fallocate+0x51/0xc0 __x64_sys_fallocate+0x24/0x40 x64_sys_call+0x18d2/0x4170 do_syscall_64+0xa7/0x220 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fix this by filtering out cases where the punching start offset exceeds max_end. Fixes: 982bf37da09d ("ext4: refactor ext4_punch_hole()") Reported-by: Liebes Wang Closes: https://lore.kernel.org/linux-ext4/ac3a58f6-e686-488b-a9ee-fc041024e43d@huawei.com/ Tested-by: Liebes Wang Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-1-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'ext4_for_linus-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2025-04-13T14:15:50Z

Pull ext4 fixes from Ted Ts'o: "A few more miscellaneous ext4 bug fixes and cleanups including some syzbot failures and fixing a stale file handing refeencing an inode previously used as a regular file, but which has been deleted and reused as an ea_inode would result in ext4 erroneously considering this a case of fs corruption" * tag 'ext4_for_linus-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix off-by-one error in do_split ext4: make block validity check resistent to sb bh corruption ext4: avoid -Wflex-array-member-not-at-end warning Documentation: ext4: Add fields to ext4_super_block documentation ext4: don't treat fhandle lookup of ea_inode as FS corruption

ext4: make block validity check resistent to sb bh corruption

2025-04-13T02:01:37Z

Block validity checks need to be skipped in case they are called for journal blocks since they are part of system's protected zone. Currently, this is done by checking inode->ino against sbi->s_es->s_journal_inum, which is a direct read from the ext4 sb buffer head. If someone modifies this underneath us then the s_journal_inum field might get corrupted. To prevent against this, change the check to directly compare the inode with journal->j_inode. **Slight change in behavior**: During journal init path, check_block_validity etc might be called for journal inode when sbi->s_journal is not set yet. In this case we now proceed with ext4_inode_block_valid() instead of returning early. Since systems zones have not been set yet, it is okay to proceed so we can perform basic checks on the blocks. Suggested-by: Baokun Li Reviewed-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Signed-off-by: Ojaswin Mujoo Link: https://patch.msgid.link/0c06bc9ebfcd6ccfed84a36e79147bf45ff5adc1.1743142920.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o

ext4: don't treat fhandle lookup of ea_inode as FS corruption

2025-04-10T14:53:50Z

A file handle that userspace provides to open_by_handle_at() can legitimately contain an outdated inode number that has since been reused for another purpose - that's why the file handle also contains a generation number. But if the inode number has been reused for an ea_inode, check_igot_inode() will notice, __ext4_iget() will go through ext4_error_inode(), and if the inode was newly created, it will also be marked as bad by iget_failed(). This all happens before the point where the inode generation is checked. ext4_error_inode() is supposed to only be used on filesystem corruption; it should not be used when userspace just got unlucky with a stale file handle. So when this happens, let __ext4_iget() just return an error. Fixes: b3e6bcb94590 ("ext4: add EA_INODE checking to ext4_iget()") Signed-off-by: Jann Horn Reviewed-by: Jan Kara Link: https://patch.msgid.link/20241129-ext4-ignore-ea-fhandle-v1-1-e532c0d1cee0@google.com Signed-off-by: Theodore Ts'o

Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-04-01T16:29:18Z

Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...

Merge tag 'ext4-for_linus-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2025-03-27T20:27:08Z

Pull ext4 updates from Ted Ts'o: "Ext4 bug fixes and cleanups, including: - hardening against maliciously fuzzed file systems - backwards compatibility for the brief period when we attempted to ignore zero-width characters - avoid potentially BUG'ing if there is a file system corruption found during the file system unmount - fix free space reporting by statfs when project quotas are enabled and the free space is less than the remaining project quota Also improve performance when replaying a journal with a very large number of revoke records (applicable for Lustre volumes)" * tag 'ext4-for_linus-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (71 commits) ext4: fix OOB read when checking dotdot dir ext4: on a remount, only log the ro or r/w state when it has changed ext4: correct the error handle in ext4_fallocate() ext4: Make sb update interval tunable ext4: avoid journaling sb update on error if journal is destroying ext4: define ext4_journal_destroy wrapper ext4: hash: simplify kzalloc(n * 1, ...) to kzalloc(n, ...) jbd2: add a missing data flush during file and fs synchronization ext4: don't over-report free space or inodes in statvfs ext4: clear DISCARD flag if device does not support discard jbd2: remove jbd2_journal_unfile_buffer() ext4: reorder capability check last ext4: update the comment about mb_optimize_scan jbd2: fix off-by-one while erasing journal ext4: remove references to bh->b_page ext4: goto right label 'out_mmap_sem' in ext4_setattr() ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all() ext4: introduce ITAIL helper jbd2: remove redundant function jbd2_journal_has_csum_v2or3_feature ext4: remove redundant function ext4_has_metadata_csum ...