-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/29/2013 02:57 AM, NeilBrown wrote: > On Thu, 11 Apr 2013 15:18:33 +0200 Jes.Sorensen@xxxxxxxxxx wrote: > >> From: Harald Hoyer <harald@xxxxxxxxxx> >> >> This does not trigger the udev inotify twice and saves a lot of blk I/O >> for the raid members. >> >> Also fixes: https://bugzilla.redhat.com/show_bug.cgi?id=947815 >> >> Signed-off-by: Harald Hoyer <harald@xxxxxxxxxx> Signed-off-by: Jes >> Sorensen <Jes.Sorensen@xxxxxxxxxx> > > (Sorry for delays. Thanks for reminders). > > That patch seems to make sense, but the description above is awfully thin. > > Why is double-open a problem exactly? What does it make udev do? And how > does that related to ID_FS_TYPE being wrong as mentioned in the bugzilla > entry. > > NeilBrown > udevd with watch enabled (inotify on /dev/sd*) gets triggered on close(), when you opened it writeable. So, if you double open() and udev wakes up from the first close(), not all information are written to disk yet, it will not get the ID_FS_TYPE. Seems like the second close() does not trigger an inotify sometimes, so it is missing afterwards all the time. Watch via inotify is just a lazy workaround, so we don't have to modify every tool to emit a "change" uevent, after they changed the disk. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJRfgYhAAoJEANOs3ABTfJw0uUQALrm0pEjlLd6XgojMTQ6xJGy y98MVcobi10O/WJyg3HV1RqjnYNu7wfpp+lFIzKRmE/sxIBj8X9ATFfjaopCGWYC /MPGsdehrCpGPPOZBlt47vTdoaKWB5meKsBm3X1I0AhA+uOxgeV2qfaijoOkHeim a4RbIUoOJIjIyvbdKCuVbs8mqcr62eMUiZBDPv/b3FcBtOOjYkWVZU14ylqujNtM WzE+soKyd6L70DvPWVY2KzJ4/5bg/fRuvFcc464k88hAqa8U36FU6MzfTuT4K+ZH a4FYJtpdrggL+IZuG5XToNR5lpR/YW/B1UBhfCjItXbr1dhX3alk+Y3xZCWvpbRF FFwAA1GJfcB8UmKp3loBX0YH4gJ8h8d6EITE0Quj38VqG4MlCl89J6ClQZYgXsf8 ZCVDX+lomiQkEp5xYyC85hmwfwepibncqfqKef8+4ABc5xWswQr89gDFPVsFZUE/ PbHzCUlAkz8lvuRSNH6k54b7nFeGn116eJgO7sKESt4uygP0o1A6WpWZI+YAMMg5 CBkxrLYM/iERP7sf8kHr3Wd5EWJNTYm6UsJjVtWStGHuB7LNDo6qPBXxzf84Mkek 1fnIqBfl6QDQBcYb+02p2vGhcTA+P/byi+j+eFQmwV8g2gbkwxhV6/t0Sizj57tC SlUZAaWHeeNK9HDgoNJ0 =zkJO -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
