On Tue, May 07, 2024 at 03:06:55PM +0530, Ritesh Harjani (IBM) wrote: > An async dio write to a sparse file can generate a lot of extents > and when we unlink this file (using rm), the kernel can be busy in umapping > and freeing those extents as part of transaction processing. > > Similarly xfs reflink remapping path can also iterate over a million > extent entries in xfs_reflink_remap_blocks(). > > Since we can busy loop in these two functions, so let's add cond_resched() > to avoid softlockup messages like these. > > watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/1:0:82435] > CPU: 1 PID: 82435 Comm: kworker/1:0 Tainted: G S L 6.9.0-rc5-0-default #1 > Workqueue: xfs-inodegc/sda2 xfs_inodegc_worker > NIP [c000000000beea10] xfs_extent_busy_trim+0x100/0x290 > LR [c000000000bee958] xfs_extent_busy_trim+0x48/0x290 > Call Trace: > xfs_alloc_get_rec+0x54/0x1b0 (unreliable) > xfs_alloc_compute_aligned+0x5c/0x144 > xfs_alloc_ag_vextent_size+0x238/0x8d4 > xfs_alloc_fix_freelist+0x540/0x694 > xfs_free_extent_fix_freelist+0x84/0xe0 > __xfs_free_extent+0x74/0x1ec > xfs_extent_free_finish_item+0xcc/0x214 > xfs_defer_finish_one+0x194/0x388 > xfs_defer_finish_noroll+0x1b4/0x5c8 > xfs_defer_finish+0x2c/0xc4 > xfs_bunmapi_range+0xa4/0x100 > xfs_itruncate_extents_flags+0x1b8/0x2f4 > xfs_inactive_truncate+0xe0/0x124 > xfs_inactive+0x30c/0x3e0 > xfs_inodegc_worker+0x140/0x234 > process_scheduled_works+0x240/0x57c > worker_thread+0x198/0x468 > kthread+0x138/0x140 > start_kernel_thread+0x14/0x18 > > run fstests generic/175 at 2024-02-02 04:40:21 > [ C17] watchdog: BUG: soft lockup - CPU#17 stuck for 23s! [xfs_io:7679] > watchdog: BUG: soft lockup - CPU#17 stuck for 23s! [xfs_io:7679] > CPU: 17 PID: 7679 Comm: xfs_io Kdump: loaded Tainted: G X 6.4.0 > NIP [c008000005e3ec94] xfs_rmapbt_diff_two_keys+0x54/0xe0 [xfs] > LR [c008000005e08798] xfs_btree_get_leaf_keys+0x110/0x1e0 [xfs] > Call Trace: > 0xc000000014107c00 (unreliable) > __xfs_btree_updkeys+0x8c/0x2c0 [xfs] > xfs_btree_update_keys+0x150/0x170 [xfs] > xfs_btree_lshift+0x534/0x660 [xfs] > xfs_btree_make_block_unfull+0x19c/0x240 [xfs] > xfs_btree_insrec+0x4e4/0x630 [xfs] > xfs_btree_insert+0x104/0x2d0 [xfs] > xfs_rmap_insert+0xc4/0x260 [xfs] > xfs_rmap_map_shared+0x228/0x630 [xfs] > xfs_rmap_finish_one+0x2d4/0x350 [xfs] > xfs_rmap_update_finish_item+0x44/0xc0 [xfs] > xfs_defer_finish_noroll+0x2e4/0x740 [xfs] > __xfs_trans_commit+0x1f4/0x400 [xfs] > xfs_reflink_remap_extent+0x2d8/0x650 [xfs] > xfs_reflink_remap_blocks+0x154/0x320 [xfs] > xfs_file_remap_range+0x138/0x3a0 [xfs] > do_clone_file_range+0x11c/0x2f0 > vfs_clone_file_range+0x60/0x1c0 > ioctl_file_clone+0x78/0x140 > sys_ioctl+0x934/0x1270 > system_call_exception+0x158/0x320 > system_call_vectored_common+0x15c/0x2ec > > Cc: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx> > Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx> LGTM, Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx> --D > --- > fs/xfs/libxfs/xfs_bmap.c | 1 + > fs/xfs/xfs_reflink.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index 656c95a22f2e..44d5381bc66f 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -6354,6 +6354,7 @@ xfs_bunmapi_range( > error = xfs_defer_finish(tpp); > if (error) > goto out; > + cond_resched(); > } > out: > return error; > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 7da0e8f961d3..5f26a608bc09 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -1417,6 +1417,7 @@ xfs_reflink_remap_blocks( > destoff += imap.br_blockcount; > len -= imap.br_blockcount; > remapped_len += imap.br_blockcount; > + cond_resched(); > } > > if (error) > -- > 2.44.0 > >