From: Ye Bin yebin10@huawei.com
[ Upstream commit 8ee81ed581ff35882b006a5205100db0b57bf070 ]
There's issue as follows: XFS: Assertion failed: (bmv->bmv_iflags & BMV_IF_DELALLOC) != 0, file: fs/xfs/xfs_bmap_util.c, line: 329 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 14612 Comm: xfs_io Not tainted 6.3.0-rc2-next-20230315-00006-g2729d23ddb3b-dirty #422 RIP: 0010:assfail+0x96/0xa0 RSP: 0018:ffffc9000fa178c0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888179a18000 RDX: 0000000000000000 RSI: ffff888179a18000 RDI: 0000000000000002 RBP: 0000000000000000 R08: ffffffff8321aab6 R09: 0000000000000000 R10: 0000000000000001 R11: ffffed1105f85139 R12: ffffffff8aacc4c0 R13: 0000000000000149 R14: ffff888269f58000 R15: 000000000000000c FS: 00007f42f27a4740(0000) GS:ffff88882fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000b92388 CR3: 000000024f006000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> xfs_getbmap+0x1a5b/0x1e40 xfs_ioc_getbmap+0x1fd/0x5b0 xfs_file_ioctl+0x2cb/0x1d50 __x64_sys_ioctl+0x197/0x210 do_syscall_64+0x39/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Above issue may happen as follows: ThreadA ThreadB do_shared_fault __do_fault xfs_filemap_fault __xfs_filemap_fault filemap_fault xfs_ioc_getbmap -> Without BMV_IF_DELALLOC flag xfs_getbmap xfs_ilock(ip, XFS_IOLOCK_SHARED); filemap_write_and_wait do_page_mkwrite xfs_filemap_page_mkwrite __xfs_filemap_fault xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); iomap_page_mkwrite ... xfs_buffered_write_iomap_begin xfs_bmapi_reserve_delalloc -> Allocate delay extent xfs_ilock_data_map_shared(ip) xfs_getbmap_report_one ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0) -> trigger BUG_ON
As xfs_filemap_page_mkwrite() only hold XFS_MMAPLOCK_SHARED lock, there's small window mkwrite can produce delay extent after file write in xfs_getbmap(). To solve above issue, just skip delalloc extents.
Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Dave Chinner dchinner@redhat.com Signed-off-by: Dave Chinner david@fromorbit.com Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Acked-by: Chandan Babu R chandanbabu@kernel.org --- fs/xfs/xfs_bmap_util.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 867645b74d88..351087cde27e 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -314,15 +314,13 @@ xfs_getbmap_report_one( if (isnullstartblock(got->br_startblock) || got->br_startblock == DELAYSTARTBLOCK) { /* - * Delalloc extents that start beyond EOF can occur due to - * speculative EOF allocation when the delalloc extent is larger - * than the largest freespace extent at conversion time. These - * extents cannot be converted by data writeback, so can exist - * here even if we are not supposed to be finding delalloc - * extents. + * Take the flush completion as being a point-in-time snapshot + * where there are no delalloc extents, and if any new ones + * have been created racily, just skip them as being 'after' + * the flush and so don't get reported. */ - if (got->br_startoff < XFS_B_TO_FSB(ip->i_mount, XFS_ISIZE(ip))) - ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0); + if (!(bmv->bmv_iflags & BMV_IF_DELALLOC)) + return 0;
p->bmv_oflags |= BMV_OF_DELALLOC; p->bmv_block = -2;