| Message ID | 20230328142129.2636535-1-yebin@huaweicloud.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] xfs: fix BUG_ON in xfs_getbmap() | expand |
On Tue, Mar 28, 2023 at 10:21:29PM +0800, Ye Bin wrote: > From: Ye Bin <yebin10@huawei.com> > > 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> > --- > fs/xfs/xfs_bmap_util.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index a09dd2606479..d2a109ceb922 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -322,7 +322,8 @@ xfs_getbmap_report_one( > * extents. > */ > 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; Why only hide the delalloc mapping if it's below EOF? --D > > p->bmv_oflags |= BMV_OF_DELALLOC; > p->bmv_block = -2; > -- > 2.31.1 >
On 2023/3/29 9:02, Darrick J. Wong wrote: > On Tue, Mar 28, 2023 at 10:21:29PM +0800, Ye Bin wrote: >> From: Ye Bin <yebin10@huawei.com> >> >> 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> >> --- >> fs/xfs/xfs_bmap_util.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c >> index a09dd2606479..d2a109ceb922 100644 >> --- a/fs/xfs/xfs_bmap_util.c >> +++ b/fs/xfs/xfs_bmap_util.c >> @@ -322,7 +322,8 @@ xfs_getbmap_report_one( >> * extents. >> */ >> 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; > Why only hide the delalloc mapping if it's below EOF? > > --D There should be no concurrency issues with normal buffer writes. But since we need to skip here, we won't make any distinction. I will send another version. >> >> p->bmv_oflags |= BMV_OF_DELALLOC; >> p->bmv_block = -2; >> -- >> 2.31.1 >> > . >
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index a09dd2606479..d2a109ceb922 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -322,7 +322,8 @@ xfs_getbmap_report_one( * extents. */ 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;