This reverts commit 60263d5889e6dc5987dc51b801be4955ff2e4aa7. Reverting since this commit opens a potential avenue for abuse.
The C-reproducer and more information can be found at the link below. With this patch applied, I can no longer get the repro to trigger. kernel BUG at fs/ext4/inode.c:2647! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 459 Comm: syz-executor359 Tainted: G W 5.10.93-syzkaller-01028-g0347b1658399 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mpage_prepare_extent_to_map+0xbe9/0xc00 fs/ext4/inode.c:2647 Code: e8 fc bd c3 ff e9 80 f6 ff ff 44 89 e9 80 e1 07 38 c1 0f 8c a6 fe ff ff 4c 89 ef e8 e1 bd c3 ff e9 99 fe ff ff e8 87 c9 89 ff <0f> 0b e8 80 c9 89 ff 0f 0b e8 79 1e b8 02 66 0f 1f 84 00 00 00 00 RSP: 0018:ffffc90000e2e9c0 EFLAGS: 00010293 RAX: ffffffff81e321f9 RBX: 0000000000000000 RCX: ffff88810c12cf00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000e2eb90 R08: ffffffff81e31e71 R09: fffff940008d68b1 R10: fffff940008d68b1 R11: 0000000000000000 R12: ffffea00046b4580 R13: ffffc90000e2ea80 R14: 000000000000011e R15: dffffc0000000000 FS: 00007fcfd0717700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcfd07d5520 CR3: 000000010a142000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_writepages+0xcbb/0x3950 fs/ext4/inode.c:2776 do_writepages+0x13a/0x280 mm/page-writeback.c:2358 __filemap_fdatawrite_range+0x356/0x420 mm/filemap.c:427 filemap_write_and_wait_range+0x64/0xe0 mm/filemap.c:660 __iomap_dio_rw+0x621/0x10c0 fs/iomap/direct-io.c:495 iomap_dio_rw+0x35/0x80 fs/iomap/direct-io.c:611 ext4_dio_write_iter fs/ext4/file.c:571 [inline] ext4_file_write_iter+0xfc5/0x1b70 fs/ext4/file.c:681 do_iter_readv_writev+0x548/0x740 include/linux/fs.h:1941 do_iter_write+0x182/0x660 fs/read_write.c:866 vfs_iter_write+0x7c/0xa0 fs/read_write.c:907 iter_file_splice_write+0x7fb/0xf70 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0xfe/0x130 fs/splice.c:933 splice_direct_to_actor+0x4f4/0xbc0 fs/splice.c:888 do_splice_direct+0x28b/0x3e0 fs/splice.c:976 do_sendfile+0x914/0x1390 fs/read_write.c:1257 Link: https://syzkaller.appspot.com/bug?extid=41c966bf0729a530bd8d >From the patch: Cc: Stable <sta...@vger.kernel.org> Cc: Christoph Hellwig <h...@lst.de> Cc: Dave Chinner <dchin...@redhat.com> Cc: Goldwyn Rodrigues <rgold...@suse.com> Cc: Darrick J. Wong <darrick.w...@oracle.com> Cc: Bob Peterson <rpete...@redhat.com> Cc: Damien Le Moal <damien.lem...@wdc.com> Cc: Theodore Ts'o <ty...@mit.edu> # for ext4 Cc: Andreas Gruenbacher <agrue...@redhat.com> Cc: Ritesh Harjani <rite...@linux.ibm.com> Others: Cc: Johannes Thumshirn <j...@kernel.org> Cc: linux-...@vger.kernel.org Cc: linux-fsde...@vger.kernel.org Cc: linux-e...@vger.kernel.org Cc: cluster-devel@redhat.com Fixes: 60263d5889e6d ("iomap: fall back to buffered writes for invalidation failures") Reported-by: syzbot+0ed9f769264276638...@syzkaller.appspotmail.com Signed-off-by: Lee Jones <lee.jo...@linaro.org> --- fs/ext4/file.c | 2 -- fs/gfs2/file.c | 3 +-- fs/iomap/direct-io.c | 16 +++++----------- fs/iomap/trace.h | 1 - fs/xfs/xfs_file.c | 4 ++-- fs/zonefs/super.c | 7 ++----- 6 files changed, 10 insertions(+), 23 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 3ed8c048fb12c..cb347c3b35535 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -551,8 +551,6 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) iomap_ops = &ext4_iomap_overwrite_ops; ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops, is_sync_kiocb(iocb) || unaligned_io || extend); - if (ret == -ENOTBLK) - ret = 0; if (extend) ret = ext4_handle_inode_extension(inode, offset, ret, count); diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index b39b339feddc9..847adb97380d3 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -835,8 +835,7 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from, ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, is_sync_kiocb(iocb)); - if (ret == -ENOTBLK) - ret = 0; + out: gfs2_glock_dq(gh); out_uninit: diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 933f234d5becd..ddcd06c0c452d 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -10,7 +10,6 @@ #include <linux/backing-dev.h> #include <linux/uio.h> #include <linux/task_io_accounting_ops.h> -#include "trace.h" #include "../internal.h" @@ -413,9 +412,6 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, * can be mapped into multiple disjoint IOs and only a subset of the IOs issued * may be pure data writes. In that case, we still need to do a full data sync * completion. - * - * Returns -ENOTBLK In case of a page invalidation invalidation failure for - * writes. The callers needs to fall back to buffered I/O in this case. */ struct iomap_dio * __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, @@ -493,15 +489,13 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iov_iter_rw(iter) == WRITE) { /* * Try to invalidate cache pages for the range we are writing. - * If this invalidation fails, let the caller fall back to - * buffered I/O. + * If this invalidation fails, tough, the write will still work, + * but racing two incompatible write paths is a pretty crazy + * thing to do, so we don't support it 100%. */ if (invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT, - end >> PAGE_SHIFT)) { - trace_iomap_dio_invalidate_fail(inode, pos, count); - ret = -ENOTBLK; - goto out_free_dio; - } + end >> PAGE_SHIFT)) + dio_warn_stale_pagecache(iocb->ki_filp); if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) { ret = sb_init_dio_done_wq(inode->i_sb); diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h index fdc7ae388476f..5693a39d52fb6 100644 --- a/fs/iomap/trace.h +++ b/fs/iomap/trace.h @@ -74,7 +74,6 @@ DEFINE_EVENT(iomap_range_class, name, \ DEFINE_RANGE_EVENT(iomap_writepage); DEFINE_RANGE_EVENT(iomap_releasepage); DEFINE_RANGE_EVENT(iomap_invalidatepage); -DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail); #define IOMAP_TYPE_STRINGS \ { IOMAP_HOLE, "HOLE" }, \ diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 5b0f93f738372..43e2c057214d9 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -589,8 +589,8 @@ xfs_file_dio_aio_write( xfs_iunlock(ip, iolock); /* - * No fallback to buffered IO after short writes for XFS, direct I/O - * will either complete fully or return an error. + * No fallback to buffered IO on errors for XFS, direct IO will either + * complete fully or fail. */ ASSERT(ret < 0 || ret == count); return ret; diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c index bec47f2d074be..d54fbef3db4df 100644 --- a/fs/zonefs/super.c +++ b/fs/zonefs/super.c @@ -851,11 +851,8 @@ static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size) return -EFBIG; - if (iocb->ki_flags & IOCB_DIRECT) { - ssize_t ret = zonefs_file_dio_write(iocb, from); - if (ret != -ENOTBLK) - return ret; - } + if (iocb->ki_flags & IOCB_DIRECT) + return zonefs_file_dio_write(iocb, from); return zonefs_file_buffered_write(iocb, from); } -- 2.35.0.263.gb82422642f-goog
