kernel/linux.git/fs/ext4/file.c, branch linux-6.0.y

ext4: avoid crash when inline data creation follows DIO write

2022-10-21T10:37:49+00:00

commit 4bb26f2885ac6930984ee451b952c5a6042f2c0e upstream. When inode is created and written to using direct IO, there is nothing to clear the EXT4_STATE_MAY_INLINE_DATA flag. Thus when inode gets truncated later to say 1 byte and written using normal write, we will try to store the data as inline data. This confuses the code later because the inode now has both normal block and inline data allocated and the confusion manifests for example as: kernel BUG at fs/ext4/inode.c:2721! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 359 Comm: repro Not tainted 5.19.0-rc8-00001-g31ba1e3b8305-dirty #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 RIP: 0010:ext4_writepages+0x363d/0x3660 RSP: 0018:ffffc90000ccf260 EFLAGS: 00010293 RAX: ffffffff81e1abcd RBX: 0000008000000000 RCX: ffff88810842a180 RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000 RBP: ffffc90000ccf650 R08: ffffffff81e17d58 R09: ffffed10222c680b R10: dfffe910222c680c R11: 1ffff110222c680a R12: ffff888111634128 R13: ffffc90000ccf880 R14: 0000008410000000 R15: 0000000000000001 FS: 00007f72635d2640(0000) GS:ffff88811b000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000565243379180 CR3: 000000010aa74000 CR4: 0000000000150eb0 Call Trace: do_writepages+0x397/0x640 filemap_fdatawrite_wbc+0x151/0x1b0 file_write_and_wait_range+0x1c9/0x2b0 ext4_sync_file+0x19e/0xa00 vfs_fsync_range+0x17b/0x190 ext4_buffered_write_iter+0x488/0x530 ext4_file_write_iter+0x449/0x1b90 vfs_write+0xbcd/0xf40 ksys_write+0x198/0x2c0 __x64_sys_write+0x7b/0x90 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix the problem by clearing EXT4_STATE_MAY_INLINE_DATA when we are doing direct IO write to a file. Cc: stable@kernel.org Reported-by: Tadeusz Struk Reported-by: syzbot+bd13648a53ed6933ca49@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=a1e89d09bbbcbd5c4cb45db230ee28c822953984 Signed-off-by: Jan Kara Reviewed-by: Lukas Czerner Tested-by: Tadeusz Struk Link: https://lore.kernel.org/r/20220727155753.13969-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

iomap: add per-iomap_iter private data

2022-05-16T15:17:32+00:00

Allow the file system to keep state for all iterations. For now only wire it up for direct I/O as there is an immediate need for it there. Reviewed-by: Darrick J. Wong Reviewed-by: Nikolay Borisov Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba Signed-off-by: David Sterba

fs: Pass an iocb to generic_perform_write()

2022-04-01T18:40:44+00:00

We can extract both the file pointer and the pos from the iocb. This simplifies each caller as well as allowing generic_perform_write() to see more of the iocb contents in the future. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: Christian Brauner Reviewed-by: Al Viro Acked-by: Al Viro

ext4: support direct I/O with fscrypt using blk-crypto

2022-02-08T19:02:12+00:00

Encrypted files traditionally haven't supported DIO, due to the need to encrypt/decrypt the data. However, when the encryption is implemented using inline encryption (blk-crypto) instead of the traditional filesystem-layer encryption, it is straightforward to support DIO. Therefore, make ext4 support DIO on files that are using inline encryption. Since ext4 uses iomap for DIO, and fscrypt support was already added to iomap DIO, this just requires two small changes: - Let DIO proceed when supported, by checking fscrypt_dio_supported() instead of assuming that encrypted files never support DIO. - In ext4_iomap_begin(), use fscrypt_limit_io_blocks() to limit the length of the mapping in the rare case where a DUN discontiguity occurs in the middle of an extent. The iomap DIO implementation requires this, since it assumes that it can submit a bio covering (up to) the whole mapping, without checking fscrypt constraints itself. Co-developed-by: Satya Tangirala Signed-off-by: Satya Tangirala Acked-by: Theodore Ts'o Reviewed-by: Jaegeuk Kim Link: https://lore.kernel.org/r/20220128233940.79464-4-ebiggers@kernel.org Signed-off-by: Eric Biggers

ext4: use ext4_journal_start/stop for fast commit transactions

2021-12-23T23:13:25+00:00

This patch drops all calls to ext4_fc_start_update() and ext4_fc_stop_update(). To ensure that there are no ongoing journal updates during fast commit, we also make jbd2_fc_begin_commit() lock journal for updates. This way we don't have to maintain two different transaction start stop APIs for fast commit and full commit. This patch doesn't remove the functions altogether since in future we want to have inode level locking for fast commits. Signed-off-by: Harshad Shirwadkar Link: https://lore.kernel.org/r/20211223202140.2061101-2-harshads@google.com Signed-off-by: Theodore Ts'o

Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

2021-11-02T19:25:03+00:00

Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher: "Functions gfs2_file_read_iter and gfs2_file_write_iter are both accessing the user buffer to write to or read from while holding the inode glock. In the most basic deadlock scenario, that buffer will not be resident and it will be mapped to the same file. Accessing the buffer will trigger a page fault, and gfs2 will deadlock trying to take the same inode glock again while trying to handle that fault. Fix that and similar, more complex scenarios by disabling page faults while accessing user buffers. To make this work, introduce a small amount of new infrastructure and fix some bugs that didn't trigger so far, with page faults enabled" * tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix mmap + page fault deadlocks for direct I/O iov_iter: Introduce nofault flag to disable page faults gup: Introduce FOLL_NOFAULT flag to disable page faults iomap: Add done_before argument to iomap_dio_rw iomap: Support partial direct I/O on user copy failures iomap: Fix iomap_dio_rw return value for user copies gfs2: Fix mmap + page fault deadlocks for buffered I/O gfs2: Eliminate ip->i_gh gfs2: Move the inode glock locking to gfs2_file_buffered_write gfs2: Introduce flag for glock holder auto-demotion gfs2: Clean up function may_grant gfs2: Add wrapper for iomap_file_buffered_write iov_iter: Introduce fault_in_iov_iter_writeable iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} powerpc/kvm: Fix kvm_use_magic_page iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value

iomap: Add done_before argument to iomap_dio_rw

2021-10-24T13:26:05+00:00

Add a done_before argument to iomap_dio_rw that indicates how much of the request has already been transferred. When the request succeeds, we report that done_before additional bytes were tranferred. This is useful for finishing a request asynchronously when part of the request has already been completed synchronously. We'll use that to allow iomap_dio_rw to be used with page faults disabled: when a page fault occurs while submitting a request, we synchronously complete the part of the request that has already been submitted. The caller can then take care of the page fault and call iomap_dio_rw again for the rest of the request, passing in the number of bytes already tranferred. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong

block: switch polling to be bio based

2021-10-18T12:17:36+00:00

Replace the blk_poll interface that requires the caller to keep a queue and cookie from the submissions with polling based on the bio. Polling for the bio itself leads to a few advantages: - the cookie construction can made entirely private in blk-mq.c - the caller does not need to remember the request_queue and cookie separately and thus sidesteps their lifetime issues - keeping the device and the cookie inside the bio allows to trivially support polling BIOs remapping by stacking drivers - a lot of code to propagate the cookie back up the submission path can be removed entirely. Signed-off-by: Christoph Hellwig Tested-by: Mark Wunderlich Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de Signed-off-by: Jens Axboe

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

2021-09-02T16:37:09+00:00

Pull ext4 updates from Ted Ts'o: "In addition to some ext4 bug fixes and cleanups, this cycle we add the orphan_file feature, which eliminates bottlenecks when doing a large number of parallel truncates and file deletions, and move the discard operation out of the jbd2 commit thread when using the discard mount option, to better support devices with slow discard operations" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (23 commits) ext4: make the updating inode data procedure atomic ext4: remove an unnecessary if statement in __ext4_get_inode_loc() ext4: move inode eio simulation behind io completeion ext4: Improve scalability of ext4 orphan file handling ext4: Orphan file documentation ext4: Speedup ext4 orphan inode handling ext4: Move orphan inode handling into a separate file ext4: Support for checksumming from journal triggers ext4: fix race writing to an inline_data file while its xattrs are changing jbd2: add sparse annotations for add_transaction_credits() ext4: fix sparse warnings ext4: Make sure quota files are not grabbed accidentally ext4: fix e2fsprogs checksum failure for mounted filesystem ext4: if zeroout fails fall back to splitting the extent node ext4: reduce arguments of ext4_fc_add_dentry_tlv ext4: flush background discard kwork when retry allocation ext4: get discard out of jbd2 commit kthread contex ext4: remove the repeated comment of ext4_trim_all_free ext4: add new helper interface ext4_try_to_trim_range() ext4: remove the 'group' parameter of ext4_trim_extent ...

ext4: Support for checksumming from journal triggers

2021-08-31T03:36:50+00:00

JBD2 layer support triggers which are called when journaling layer moves buffer to a certain state. We can use the frozen trigger, which gets called when buffer data is frozen and about to be written out to the journal, to compute block checksums for some buffer types (similarly as does ocfs2). This avoids unnecessary repeated recomputation of the checksum (at the cost of larger window where memory corruption won't be caught by checksumming) and is even necessary when there are unsynchronized updaters of the checksummed data. So add superblock and journal trigger type arguments to ext4_journal_get_write_access() and ext4_journal_get_create_access() so that frozen triggers can be set accordingly. Also add inode argument to ext4_walk_page_buffers() and all the callbacks used with that function for the same purpose. This patch is mostly only a change of prototype of the above mentioned functions and a few small helpers. Real checksumming will come later. Reviewed-by: Theodore Ts'o Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz Signed-off-by: Theodore Ts'o