* quick question about write-intent bitmap @ 2011-12-01 6:34 Marcus Sorensen 2011-12-01 7:18 ` NeilBrown 0 siblings, 1 reply; 2+ messages in thread From: Marcus Sorensen @ 2011-12-01 6:34 UTC (permalink / raw) To: linux-raid I would appreciate being pointed to any sort of in-depth documentation on how the write intent bitmap works. To make my question quick, I'm wondering how the write-intent bitmap holds up to writeback caching. It seems like md would assume that the cached writes had made it to disk, and only rebuild writes that happened since the disk was removed, leaving an inconsistent array. ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: quick question about write-intent bitmap 2011-12-01 6:34 quick question about write-intent bitmap Marcus Sorensen @ 2011-12-01 7:18 ` NeilBrown 0 siblings, 0 replies; 2+ messages in thread From: NeilBrown @ 2011-12-01 7:18 UTC (permalink / raw) To: Marcus Sorensen; +Cc: linux-raid [-- Attachment #1: Type: text/plain, Size: 722 bytes --] On Wed, 30 Nov 2011 23:34:13 -0700 Marcus Sorensen <shadowsor@gmail.com> wrote: > I would appreciate being pointed to any sort of in-depth documentation > on how the write intent bitmap works. To make my question quick, I'm > wondering how the write-intent bitmap holds up to writeback caching. > It seems like md would assume that the cached writes had made it to > disk, and only rebuild writes that happened since the disk was > removed, leaving an inconsistent array. > md writes bitmaps with REQ_WRITE | REQ_SYNC | REQ_FLUSH | REQ_FUA If that returns before the data is truly safe, then you have a bug somewhere. i.e. md tries to write-through an cache that might be in the way. NeilBrown [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 828 bytes --] ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2011-12-01 7:18 UTC | newest] Thread overview: 2+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2011-12-01 6:34 quick question about write-intent bitmap Marcus Sorensen 2011-12-01 7:18 ` NeilBrown
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).