On Fri 14-06-24 08:56:10, NeilBrown wrote: > On Thu, 13 Jun 2024, Jan Kara wrote: > > @@ -698,12 +700,14 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) > > struct nfs_pageio_descriptor pgio; > > struct nfs_io_completion *ioc = NULL; > > unsigned int mntflags = NFS_SERVER(inode)->flags; > > + struct nfs_server *nfss = NFS_SERVER(inode); > > int priority = 0; > > int err; > > > > - if (wbc->sync_mode == WB_SYNC_NONE && > > - NFS_SERVER(inode)->write_congested) > > - return 0; > > + /* Wait with writeback until write congestion eases */ > > + if (wbc->sync_mode == WB_SYNC_NONE && nfss->write_congested) > > + wait_event(nfss->write_congestion_wait, > > + nfss->write_congested == 0); > > If there is a network problem or the server reboot, this could wait > indefinitely. Maybe wait_event_idle() ?? > > Is this only called from the writeback thread that is dedicated to this > fs? If so that should be fine. If it can be reached from a user > processes, then wait_event_killable() might be needed. Usually yes, but e.g. sync_file_range() can issue writeback that will block here as well. So I guess wait_event_killable() is a good idea. I'll update it. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
