On Tue, 2020-10-13 at 14:40 -0400, Vivek Goyal wrote: > > == the thread is stuck in the loop == > > [10813.290694] task:trinity-c33 state:D stack:25888 pid:254219 ppid: > > 87180 > > flags:0x00004004 > > [10813.292671] Call Trace: > > [10813.293379] __schedule+0x71d/0x1b50 > > [10813.294182] ? __sched_text_start+0x8/0x8 > > [10813.295146] ? mark_held_locks+0xb0/0x110 > > [10813.296117] schedule+0xbf/0x270 > > [10813.296782] ? __lock_page_killable+0x276/0x830 > > [10813.297867] io_schedule+0x17/0x60 > > [10813.298772] __lock_page_killable+0x33b/0x830 > > This seems to suggest that filemap_fault() is blocked on page lock and > is sleeping. For some reason it never wakes up. Not sure why. > > And this will be called from. > > fuse_fill_write_pages() > iov_iter_fault_in_readable() > > So fuse code will take inode_lock() and then looks like same process > is sleeping waiting on page lock. And rest of the processes get blocked > behind inode lock. > > If we are woken up (while waiting on page lock), we should make forward > progress. Question is what page it is and why the entity which is > holding lock is not releasing lock.
FYI, it was mentioned that this is likely a deadlock in FUSE: https://lore.kernel.org/linux-fsdevel/CAHk-=wh9Eu-gNHzqgfvUAAiO=vj+pwnzxkv+tx55xhgpfy+...@mail.gmail.com/
