From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Christoph Hellwig reported seeing the following assertion in generic/051: XFS: Assertion failed: tp->t_firstblock == NULLFSBLOCK, file: fs/xfs/libxfs5 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! invalid opcode: 0000 [#1] SMP PTI CPU: 2 PID: 20757 Comm: fsstress Not tainted 4.18.0-rc4+ #3969 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/4 RIP: 0010:assfail+0x23/0x30 Code: c3 66 0f 1f 44 00 00 48 89 f1 41 89 d0 48 c7 c6 88 e0 8c 82 48 89 fa RSP: 0018:ffff88012dc43c08 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88012dc43ca0 RCX: 0000000000000000 RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828480eb RBP: ffff88012aa92758 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: f000000000000000 R12: 0000000000000000 R13: ffff88012dc43d48 R14: ffff88013092e7e8 R15: 0000000000000014 FS: 00007f8d689b8e80(0000) GS:ffff88013fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8d689c7000 CR3: 000000012ba6a000 CR4: 00000000000006e0 Call Trace: xfs_defer_init+0xff/0x160 xfs_reflink_remap_extent+0x31b/0xa00 xfs_reflink_remap_blocks+0xec/0x4a0 xfs_reflink_remap_range+0x3a1/0x650 xfs_file_dedupe_range+0x39/0x50 vfs_dedupe_file_range+0x218/0x260 do_vfs_ioctl+0x262/0x6a0 ? __se_sys_newfstat+0x3c/0x60 ksys_ioctl+0x35/0x60 __x64_sys_ioctl+0x11/0x20 do_syscall_64+0x4b/0x190 entry_SYSCALL_64_after_hwframe+0x49/0xbe The root cause of the assertion failure is that xfs_defer_finish doesn't roll the transaction after processing all the deferred items. Therefore it returns a dirty transaction to the caller, which leaves the caller at risk of exceeding the transaction reservation if it logs more items. Brian Foster's patchset to move the defer_ops firstblock into the transaction requires t_firstblock == NULLFSBLOCK upon defer_ops initialization, which is how this was noticed at all. Reported-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --- fs/xfs/libxfs/xfs_defer.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c index c3e5bffda4f5..3ba8bb308c3c 100644 --- a/fs/xfs/libxfs/xfs_defer.c +++ b/fs/xfs/libxfs/xfs_defer.c @@ -424,6 +424,12 @@ xfs_defer_finish( cleanup_fn(*tp, state, error); } + /* + * Roll the transaction once more to avoid returning to the caller + * with a dirty transaction. + */ + if ((*tp)->t_flags & XFS_TRANS_DIRTY) + error = xfs_defer_trans_roll(tp, dop); out: (*tp)->t_agfl_dfops = orig_dop; if (error) -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
