kernel/linux.git/fs/iomap, branch linux-6.0.y

iomap: iomap: fix memory corruption when recording errors during writeback

2022-10-21T10:38:36+00:00

[ Upstream commit 3d5f3ba1ac28059bdf7000cae2403e4e984308d2 ] Every now and then I see this crash on arm64: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8 Buffer I/O error on dev dm-0, logical block 8733687, async page read Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 64k pages, 42-bit VAs, pgdp=0000000139750000 [00000000000000f8] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP Buffer I/O error on dev dm-0, logical block 8733688, async page read Dumping ftrace buffer: Buffer I/O error on dev dm-0, logical block 8733689, async page read (ftrace buffer empty) XFS (dm-0): log I/O error -5 Modules linked in: dm_thin_pool dm_persistent_data XFS (dm-0): Metadata I/O Error (0x1) detected at xfs_trans_read_buf_map+0x1ec/0x590 [xfs] (fs/xfs/xfs_trans_buf.c:296). dm_bio_prison XFS (dm-0): Please unmount the filesystem and rectify the problem(s) XFS (dm-0): xfs_imap_lookup: xfs_ialloc_read_agi() returned error -5, agno 0 dm_bufio dm_log_writes xfs nft_chain_nat xt_REDIRECT nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip6t_REJECT potentially unexpected fatal signal 6. nf_reject_ipv6 potentially unexpected fatal signal 6. ipt_REJECT nf_reject_ipv4 CPU: 1 PID: 122166 Comm: fsstress Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7 rpcsec_gss_krb5 auth_rpcgss xt_tcpudp ip_set_hash_ip ip_set_hash_net xt_set nft_compat ip_set_hash_mac ip_set nf_tables Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021 pstate: 60001000 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--) ip_tables pc : 000003fd6d7df200 x_tables lr : 000003fd6d7df1ec overlay nfsv4 CPU: 0 PID: 54031 Comm: u4:3 Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7405 Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021 Workqueue: writeback wb_workfn sp : 000003ffd9522fd0 (flush-253:0) pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--) pc : errseq_set+0x1c/0x100 x29: 000003ffd9522fd0 x28: 0000000000000023 x27: 000002acefeb6780 x26: 0000000000000005 x25: 0000000000000001 x24: 0000000000000000 x23: 00000000ffffffff x22: 0000000000000005 lr : __filemap_set_wb_err+0x24/0xe0 x21: 0000000000000006 sp : fffffe000f80f760 x29: fffffe000f80f760 x28: 0000000000000003 x27: fffffe000f80f9f8 x26: 0000000002523000 x25: 00000000fffffffb x24: fffffe000f80f868 x23: fffffe000f80fbb0 x22: fffffc0180c26a78 x21: 0000000002530000 x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000001 x13: 0000000000470af3 x12: fffffc0058f70000 x11: 0000000000000040 x10: 0000000000001b20 x9 : fffffe000836b288 x8 : fffffc00eb9fd480 x7 : 0000000000f83659 x6 : 0000000000000000 x5 : 0000000000000869 x4 : 0000000000000005 x3 : 00000000000000f8 x20: 000003fd6d740020 x19: 000000000001dd36 x18: 0000000000000001 x17: 000003fd6d78704c x16: 0000000000000001 x15: 000002acfac87668 x2 : 0000000000000ffa x1 : 00000000fffffffb x0 : 00000000000000f8 Call trace: errseq_set+0x1c/0x100 __filemap_set_wb_err+0x24/0xe0 iomap_do_writepage+0x5e4/0xd5c write_cache_pages+0x208/0x674 iomap_writepages+0x34/0x60 xfs_vm_writepages+0x8c/0xcc [xfs 7a861f39c43631f15d3a5884246ba5035d4ca78b] x14: 0000000000000000 x13: 2064656e72757465 x12: 0000000000002180 x11: 000003fd6d8a82d0 x10: 0000000000000000 x9 : 000003fd6d8ae288 x8 : 0000000000000083 x7 : 00000000ffffffff x6 : 00000000ffffffee x5 : 00000000fbad2887 x4 : 000003fd6d9abb58 x3 : 000003fd6d740020 x2 : 0000000000000006 x1 : 000000000001dd36 x0 : 0000000000000000 CPU: 1 PID: 122167 Comm: fsstress Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7 do_writepages+0x90/0x1c4 __writeback_single_inode+0x4c/0x4ac Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021 writeback_sb_inodes+0x214/0x4ac wb_writeback+0xf4/0x3b0 pstate: 60001000 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--) wb_workfn+0xfc/0x580 process_one_work+0x1e8/0x480 pc : 000003fd6d7df200 worker_thread+0x78/0x430 This crash is a result of iomap_writepage_map encountering some sort of error during writeback and wanting to set that error code in the file mapping so that fsync will report it. Unfortunately, the code dereferences folio->mapping after unlocking the folio, which means that another thread could have removed the page from the page cache (writeback doesn't hold the invalidation lock) and give it to somebody else. At best we crash the system like above; at worst, we corrupt memory or set an error on some other unsuspecting file while failing to record the problems with *this* file. Regardless, fix the problem by reporting the error to the inode mapping. NOTE: Commit 598ecfbaa742 lifted the XFS writeback code to iomap, so this fix should be backported to XFS in the 4.6-5.4 kernels in addition to iomap in the 5.5-5.19 kernels. Fixes: e735c0079465 ("iomap: Convert iomap_add_to_ioend() to take a folio") # 5.17 onward Fixes: 598ecfbaa742 ("iomap: lift the xfs writeback code to iomap") # 5.5-5.16, needs backporting Fixes: 150d5be09ce4 ("xfs: remove xfs_cancel_ioend") # 4.6-5.4, needs backporting Signed-off-by: Darrick J. Wong Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Sasha Levin

Merge tag 'iomap-6.0-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2022-08-11T20:11:49+00:00

Pull more iomap updates from Darrick Wong: "In the past 10 days or so I've not heard any ZOMG STOP style complaints about removing ->writepage support from gfs2 or zonefs, so here's the pull request removing them (and the underlying fs iomap support) from the kernel: - Remove iomap_writepage and all callers, since the mm apparently never called the zonefs or gfs2 writepage functions" * tag 'iomap-6.0-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: iomap: remove iomap_writepage zonefs: remove ->writepage gfs2: remove ->writepage gfs2: stop using generic_writepages in gfs2_ail1_start_one

new iov_iter flavour - ITER_UBUF

2022-08-09T02:37:15+00:00

Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro

Merge tag 'iomap-5.20-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2022-08-03T22:16:49+00:00

Pull iomap updates from Darrick Wong: "The most notable change in this first batch is that we no longer schedule pages beyond i_size for writeback, preferring instead to let truncate deal with those pages. Next week, there may be a second pull request to remove iomap_writepage from the other two filesystems (gfs2/zonefs) that use iomap for buffered IO. This follows in the same vein as the recent removal of writepage from XFS, since it hasn't been triggered in a few years; it does nothing during direct reclaim; and as far as the people who examined the patchset can tell, it's moving the codebase in the right direction. However, as it was a late addition to for-next, I'm holding off on that section for another week of testing to see if anyone can come up with a solid reason for holding off in the meantime. Summary: - Skip writeback for pages that are completely beyond EOF - Minor code cleanups" * tag 'iomap-5.20-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: dax: set did_zero to true when zeroing successfully iomap: set did_zero to true when zeroing successfully iomap: skip pages past eof in iomap_do_writepage()

Merge tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-08-03T20:50:22+00:00

Pull vfs iov_iter updates from Al Viro: "Part 1 - isolated cleanups and optimizations. One of the goals is to reduce the overhead of using ->read_iter() and ->write_iter() instead of ->read()/->write(). new_sync_{read,write}() has a surprising amount of overhead, in particular inside iocb_flags(). That's the explanation for the beginning of the series is in this pile; it's not directly iov_iter-related, but it's a part of the same work..." * tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: first_iovec_segment(): just return address iov_iter: massage calling conventions for first_{iovec,bvec}_segment() iov_iter: first_{iovec,bvec}_segment() - simplify a bit iov_iter: lift dealing with maxpages out of first_{iovec,bvec}_segment() iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT iov_iter_bvec_advance(): don't bother with bvec_iter copy_page_{to,from}_iter(): switch iovec variants to generic keep iocb_flags() result cached in struct file iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC struct file: use anonymous union member for rcuhead and llist btrfs: use IOMAP_DIO_NOSYNC teach iomap_dio_rw() to suppress dsync No need of likely/unlikely on calls of check_copy_size()

Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache

2022-08-03T17:35:43+00:00

Pull folio updates from Matthew Wilcox: - Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) * tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits) fs: remove the NULL get_block case in mpage_writepages fs: don't call ->writepage from __mpage_writepage fs: remove the nobh helpers jfs: stop using the nobh helper ext2: remove nobh support ntfs3: refactor ntfs_writepages mm/folio-compat: Remove migration compatibility functions fs: Remove aops->migratepage() secretmem: Convert to migrate_folio hugetlb: Convert to migrate_folio aio: Convert to migrate_folio f2fs: Convert to filemap_migrate_folio() ubifs: Convert to filemap_migrate_folio() btrfs: Convert btrfs_migratepage to migrate_folio mm/migrate: Add filemap_migrate_folio() mm/migrate: Convert migrate_page() to migrate_folio() nfs: Convert to migrate_folio btrfs: Convert btree_migratepage to migrate_folio mm/migrate: Convert expected_page_refs() to folio_expected_refs() mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio() ...

Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block

2022-08-02T20:46:35+00:00

Pull block updates from Jens Axboe: - Improve the type checking of request flags (Bart) - Ensure queue mapping for a single queues always picks the right queue (Bart) - Sanitize the io priority handling (Jan) - rq-qos race fix (Jinke) - Reserved tags handling improvements (John) - Separate memory alignment from file/disk offset aligment for O_DIRECT (Keith) - Add new ublk driver, userspace block driver using io_uring for communication with the userspace backend (Ming) - Use try_cmpxchg() to cleanup the code in various spots (Uros) - Finally remove bdevname() (Christoph) - Clean up the zoned device handling (Christoph) - Clean up independent access range support (Christoph) - Clean up and improve block sysfs handling (Christoph) - Clean up and improve teardown of block devices. This turns the usual two step process into something that is simpler to implement and handle in block drivers (Christoph) - Clean up chunk size handling (Christoph) - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu, Ming, Sebastian, Yang, Ying) * tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits) ublk_drv: fix double shift bug ublk_drv: make sure that correct flags(features) returned to userspace ublk_drv: fix error handling of ublk_add_dev ublk_drv: fix lockdep warning block: remove __blk_get_queue block: call blk_mq_exit_queue from disk_release for never added disks blk-mq: fix error handling in __blk_mq_alloc_disk ublk: defer disk allocation ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask ublk: fold __ublk_create_dev into ublk_ctrl_add_dev ublk: cleanup ublk_ctrl_uring_cmd ublk: simplify ublk_ch_open and ublk_ch_release ublk: remove the empty open and release block device operations ublk: remove UBLK_IO_F_PREFLUSH ublk: add a MAINTAINERS entry block: don't allow the same type rq_qos add more than once mmc: fix disk/queue leak in case of adding disk failure ublk_drv: fix an IS_ERR() vs NULL check ublk: remove UBLK_IO_F_INTEGRITY ublk_drv: remove unneeded semicolon ...

mm/migrate: Add filemap_migrate_folio()

2022-08-02T16:34:04+00:00

There is nothing iomap-specific about iomap_migratepage(), and it fits a pattern used by several other filesystems, so move it to mm/migrate.c, convert it to be filemap_migrate_folio() and convert the iomap filesystems to use it. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong

iomap: Return -EAGAIN from iomap_write_iter()

2022-07-25T00:39:31+00:00

If iomap_write_iter() encounters -EAGAIN, return -EAGAIN to the caller. Signed-off-by: Stefan Roesch Reviewed-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220623175157.1715274-7-shr@fb.com Reviewed-by: Christoph Hellwig [axboe: make the suggested ternary edit] Signed-off-by: Jens Axboe

iomap: Add async buffered write support

2022-07-25T00:39:31+00:00

This adds async buffered write support to iomap. This replaces the call to balance_dirty_pages_ratelimited() with the call to balance_dirty_pages_ratelimited_flags. This allows to specify if the write request is async or not. In addition this also moves the above function call to the beginning of the function. If the function call is at the end of the function and the decision is made to throttle writes, then there is no request that io-uring can wait on. By moving it to the beginning of the function, the write request is not issued, but returns -EAGAIN instead. io-uring will punt the request and process it in the io-worker. By moving the function call to the beginning of the function, the write throttling will happen one page later. Signed-off-by: Stefan Roesch Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220623175157.1715274-6-shr@fb.com Signed-off-by: Jens Axboe