On 03/29/2018 08:41 PM, Matthew Wilcox wrote: > From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> > > I'd like to thank Andrew for taking the first eight XArray patches > into -next. He's understandably nervous about taking the rest of the > patches into -next given how few of the remaining patches have review > tags on them. So ... if you're on the cc, I'd really appreciate a review > on something that you feel somewhat responsible for, eg the particular > filesystem (nilfs, f2fs, lustre) that I've touched, or something in the > mm/ or fs/ directories that you've worked on recently. > > This is against next-20180329. > I applied this series to next-20180329 and booted in a debug environment. My root fs is ext4, and next-20180329 had the first (bad) fix in bug https://bugzilla.kernel.org/show_bug.cgi?id=199185 so, I had to apply the revised fix. Running with this XArray series on top of next-20180329 consistently 'hangs' on shutdown looping (?forever?) in tag_pages_for_writeback/xas_for_each_tag. All I have to do is make sure there is some activity on the ext4 fs before shutdown. Not sure if this is a 'next-20180329' issue or XArray issue. But the fact that we are looping in xas_for_each_tag looks suspicious. #0 xas_find_chunk (tag=<optimized out>, advance=<optimized out>, xas=<optimized out>) at ./include/linux/xarray.h:886 #1 xas_next_tag (tag=<optimized out>, max=<optimized out>, xas=<optimized out>) at ./include/linux/xarray.h:915 #2 tag_pages_for_writeback (mapping=<optimized out>, start=<optimized out>, end=2251799813685247) at mm/page-writeback.c:2109 #3 0xffffffff812eccf0 in ext4_writepages (mapping=0xffff88012bf9b918, wbc=<optimized out>) at fs/ext4/inode.c:2793 #4 0xffffffff811bbe4b in do_writepages (mapping=0xffffc90001727a28, wbc=0xffffffffffffffff) at mm/page-writeback.c:2332 #5 0xffffffff812743bd in __writeback_single_inode (inode=0xffffc90001727a28, wbc=0xffffc90001727cc0) at fs/fs-writeback.c:1315 #6 0xffffffff81274aaf in writeback_sb_inodes (sb=0xffff88012e2e2e98, wb=0xffff88012c02e000, work=0xffff88012c4aae18) at fs/fs-writeback.c:1579 #7 0xffffffff81274ff7 in wb_writeback (wb=0xffff88012c02e000, work=0xffff88012c4aae18) at fs/fs-writeback.c:1755 #8 0xffffffff812757df in wb_do_writeback (wb=<optimized out>) at fs/fs-writeback.c:1900 #9 wb_workfn (work=0xffffc90001727a28) at fs/fs-writeback.c:1941 #10 0xffffffff810b7415 in process_one_work (worker=0xffff88012eff6d68, work=0xffff88012c02e190) at kernel/workqueue.c:2145 #11 0xffffffff810b762e in worker_thread (__worker=0xffff88012eff6d68) at kernel/workqueue.c:2279 #12 0xffffffff810bd7c3 in kthread (_create=0xffff88012e88fc28) at kernel/kthread.c:238 #13 0xffffffff81a00205 in ret_from_fork () at arch/x86/entry/entry_64.S:411 #14 0x0000000000000000 in ?? () -- Mike Kravetz
