kernel.git/fs/ext4/inode.c, branch linux-6.4.y

ext4: only update i_reserved_data_blocks on successful block allocation

2023-07-23T11:53:57Z

commit de25d6e9610a8b30cce9bbb19b50615d02ebca02 upstream. In our fault injection test, we create an ext4 file, migrate it to non-extent based file, then punch a hole and finally trigger a WARN_ON in the ext4_da_update_reserve_space(): EXT4-fs warning (device sda): ext4_da_update_reserve_space:369: ino 14, used 11 with only 10 reserved data blocks When writing back a non-extent based file, if we enable delalloc, the number of reserved blocks will be subtracted from the number of blocks mapped by ext4_ind_map_blocks(), and the extent status tree will be updated. We update the extent status tree by first removing the old extent_status and then inserting the new extent_status. If the block range we remove happens to be in an extent, then we need to allocate another extent_status with ext4_es_alloc_extent(). use old to remove to add new |----------|------------|------------| old extent_status The problem is that the allocation of a new extent_status failed due to a fault injection, and __es_shrink() did not get free memory, resulting in a return of -ENOMEM. Then do_writepages() retries after receiving -ENOMEM, we map to the same extent again, and the number of reserved blocks is again subtracted from the number of blocks in that extent. Since the blocks in the same extent are subtracted twice, we end up triggering WARN_ON at ext4_da_update_reserve_space() because used > ei->i_reserved_data_blocks. For non-extent based file, we update the number of reserved blocks after ext4_ind_map_blocks() is executed, which causes a problem that when we call ext4_ind_map_blocks() to create a block, it doesn't always create a block, but we always reduce the number of reserved blocks. So we move the logic for updating reserved blocks to ext4_ind_map_blocks() to ensure that the number of reserved blocks is updated only after we do succeed in allocating some new blocks. Fixes: 5f634d064c70 ("ext4: Fix quota accounting error with fallocate") Cc: stable@kernel.org Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230424033846.4732-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: disallow ea_inodes with extended attributes

2023-05-30T19:33:57Z

An ea_inode stores the value of an extended attribute; it can not have extended attributes itself, or this will cause recursive nightmares. Add a check in ext4_iget() to make sure this is the case. Cc: stable@kernel.org Reported-by: syzbot+e44749b6ba4d0434cd47@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230524034951.779531-4-tytso@mit.edu Signed-off-by: Theodore Ts'o

ext4: add EA_INODE checking to ext4_iget()

2023-05-28T18:18:03Z

Add a new flag, EXT4_IGET_EA_INODE which indicates whether the inode is expected to have the EA_INODE flag or not. If the flag is not set/clear as expected, then fail the iget() operation and mark the file system as corrupted. This commit also makes the ext4_iget() always perform the is_bad_inode() check even when the inode is already inode cache. This allows us to remove the is_bad_inode() check from the callers of ext4_iget() in the ea_inode code. Reported-by: syzbot+cbb68193bdb95af4340a@syzkaller.appspotmail.com Reported-by: syzbot+62120febbd1ee3c3c860@syzkaller.appspotmail.com Reported-by: syzbot+edce54daffee36421b4c@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230524034951.779531-2-tytso@mit.edu Signed-off-by: Theodore Ts'o

ext4: check iomap type only if ext4_iomap_begin() does not fail

2023-05-13T22:05:04Z

When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may fail for some reason (e.g. memory allocation failure, bare disk write), and later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4 iomap_begin() returns an error, it is normal that the type of iomap->type may not match the expectation. Therefore, we only determine if iomap->type is as expected when ext4_iomap_begin() is executed successfully. Cc: stable@kernel.org Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@google.com Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@huawei.com Signed-off-by: Theodore Ts'o

ext4: avoid deadlock in fs reclaim with page writeback

2023-05-13T22:05:04Z

Ext4 has a filesystem wide lock protecting ext4_writepages() calls to avoid races with switching of journalled data flag or inode format. This lock can however cause a deadlock like: CPU0 CPU1 ext4_writepages() percpu_down_read(sbi->s_writepages_rwsem); ext4_change_inode_journal_flag() percpu_down_write(sbi->s_writepages_rwsem); - blocks, all readers block from now on ext4_do_writepages() ext4_init_io_end() kmem_cache_zalloc(io_end_cachep, GFP_KERNEL) fs_reclaim frees dentry... dentry_unlink_inode() iput() - last ref => iput_final() - inode dirty => write_inode_now()... ext4_writepages() tries to acquire sbi->s_writepages_rwsem and blocks forever Make sure we cannot recurse into filesystem reclaim from writeback code to avoid the deadlock. Reported-by: syzbot+6898da502aef574c5f8a@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/0000000000004c66b405fa108e27@google.com Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal mode and ext4_writepages") CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230504124723.20205-1-jack@suse.cz Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-05-01T18:00:04Z

Pull ext4 fixes from Ted Ts'o: "Some ext4 regression and bug fixes" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: clean up error handling in __ext4_fill_super() ext4: reflect error codes from ext4_multi_mount_protect() to its callers ext4: fix lost error code reporting in __ext4_fill_super() ext4: fix unused iterator variable warnings ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline ext4: fix i_disksize exceeding i_size problem in paritally written case

ext4: fix i_disksize exceeding i_size problem in paritally written case

2023-04-28T15:07:19Z

It is possible for i_disksize can exceed i_size, triggering a warning. generic_perform_write copied = iov_iter_copy_from_user_atomic(len) // copied < len ext4_da_write_end | ext4_update_i_disksize | new_i_size = pos + copied; | WRITE_ONCE(EXT4_I(inode)->i_disksize, newsize) // update i_disksize | generic_write_end | copied = block_write_end(copied, len) // copied = 0 | if (unlikely(copied < len)) | if (!PageUptodate(page)) | copied = 0; | if (pos + copied > inode->i_size) // return false if (unlikely(copied == 0)) goto again; if (unlikely(iov_iter_fault_in_readable(i, bytes))) { status = -EFAULT; break; } We get i_disksize greater than i_size here, which could trigger WARNING check 'i_size_read(inode) < EXT4_I(inode)->i_disksize' while doing dio: ext4_dio_write_iter iomap_dio_rw __iomap_dio_rw // return err, length is not aligned to 512 ext4_handle_inode_extension WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize) // Oops WARNING: CPU: 2 PID: 2609 at fs/ext4/file.c:319 CPU: 2 PID: 2609 Comm: aa Not tainted 6.3.0-rc2 RIP: 0010:ext4_file_write_iter+0xbc7 Call Trace: vfs_write+0x3b1 ksys_write+0x77 do_syscall_64+0x39 Fix it by updating 'copied' value before updating i_disksize just like ext4_write_inline_data_end() does. A reproducer can be found in the buganizer link below. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217209 Fixes: 64769240bd07 ("ext4: Add delayed allocation support in data=writeback mode") Signed-off-by: Zhihao Cheng Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230321013721.89818-1-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o

Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-04-28T02:42:02Z

Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...

Revert "ext4: Fix warnings when freezing filesystem with journaled data"

2023-04-15T00:02:37Z

After making ext4_writepages() properly clean all pages there is no need for special treatment of filesystem freezing. Revert commit e6c28a26b799c7640b77daff3e4a67808c74381c. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230329154950.19720-13-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: Update comment in mpage_prepare_extent_to_map()

2023-04-14T23:58:33Z

Since filemap_write_and_wait() is now enough to get journalled data to final location update the comment in mpage_prepare_extent_to_map(). Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230329154950.19720-12-jack@suse.cz Signed-off-by: Theodore Ts'o