On Sat, Jun 26, 2010 at 09:24:27PM +0200, Milan Broz wrote: > On 06/26/2010 08:36 PM, Arno Wagner wrote: >> On Sat, Jun 26, 2010 at 04:21:52PM +0200, Christoph Anton Mitterer wrote: > >>> And I'm not even sure if flushing alone is enough,... or where one needs >>> something like barriers... >> >> Barriesrs are a filesystem concept and play no role here. > > Nope, "IO barriers" here are block level functionality. > > See Documentation/block/barrier.txt in kernel > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/block/barrier.txt;hb=HEAD > > (yes, it is confusing:-) Ah, I see. Must have confused it with something. Thanks and sorry for my misstatement. >> Flushing ("fdatasync" or "fsunc") is not enough in some cases, >> hence the ro-remount, which is. > > fsycn currently in kerenl issues barrier in block layer and > then waits for it. Good. My information here is admittedly pretty old. > But if because ever reads can cause some metadata updates (last > access on file stamp), remounting read-only is there. Ok.Thanks again. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
