On Sat, 2008-06-21 at 09:21 -0500, Jody French wrote: > Evgeniy Polyakov wrote: > >> Either way, if we really want to do a second attempt to write out > the > >> pagevec, then adding some code to cifs_writepages that sleeps for a > bit > >> and implements this seems like the thing to do. I'm not convinced > that > >> it will actually make much difference, but it seems unlikely to > hurt > >> anything. > >> > > > > If server returns serious error then there is no other way except to > > discard data with error, but if server does not respond or respond EBUSY > > or that kind of error, then subsequent write can succeed and at least > > should not harm. As a simple case, it is possible to sleep a bit and > > resend in writepages(), but it is also possible just to return from the > > callback and allow VFS to call it again (frequently it will happen very > > soon though) with the same pages (or even increased chunk). > > > In the particular case we are looking at, the network stack (TCP perhaps > due a temporary glitch in > the network adapter or routing infrastructure or temporary memory > pressure) is returning EAGAIN > for more than 15 seconds (on the tcp send of the Write request) but the > server itself has not crashed, > (subsequent parts of the file written via later writepages requests are > eventually written out), eventually > we give up in writepages and return EIO on the next fsync or flush/close If you are getting EAGAIN, you shouldn't give up with an error. It would be better to call redirty_page_for_writeback() and let the page stay dirty a bit longer. Shaggy -- David Kleikamp IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
