On Fri, Dec 30, 2011 at 5:01 AM, Darrick J. Wong <djwong@xxxxxxxxxx> wrote: > On Wed, Dec 28, 2011 at 01:56:43PM -0500, Ted Ts'o wrote: >> On Tue, Nov 15, 2011 at 04:07:53PM +0800, Yongqiang Yang wrote: >> > When switching from journal data mode, the data blocks >> > in journal will have no revoke record. Thus, data could be >> > corrupted during replay. However, there is no such problem in >> > switching to journal data mode. So we flush journal only in >> > the case that swithes from journal data mode. >> > >> > Signed-off-by: Yongqiang Yang <xiaoqiangnk@xxxxxxxxx> >> >> Applied, with a slightly different (and more explanatory commit >> message): >> >> ext4: flush journal when switching from data=journal mode >> >> From: Yongqiang Yang <xiaoqiangnk@xxxxxxxxx> >> >> It's necessary to flush the journal when switching away from >> data=journal mode. This is because there are no revoke records when >> we are data blocks are journalled, > > Minor nit, but did you mean "when data blocks are journalled" ? Yes! chattr +j can change journal mode of a file to data mode. Yongqiang. > > --D >> which are required in the other journal modes. >> >> However, it is not necessary to flush the journal when switching into >> data=journal mode, and flushing the journal is expensive. So let's >> avoid it in that case. >> >> Signed-off-by: Yongqiang Yang <xiaoqiangnk@xxxxxxxxx> >> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> >> >> - Ted >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- Best Wishes Yongqiang Yang -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
