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| author | NeilBrown <neilb@cse.unsw.edu.au> | 2005-09-10 01:23:54 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-10 01:39:12 +0200 |
| commit | 72626685dc66d455742a7f215a0535c551628b9e (patch) | |
| tree | 91e19a61a5a3b782007132b6b2e353e8936dd656 /drivers/md/raid6main.c | |
| parent | [PATCH] md: limit size of sb read/written to appropriate amount (diff) | |
| download | linux-72626685dc66d455742a7f215a0535c551628b9e.tar.xz linux-72626685dc66d455742a7f215a0535c551628b9e.zip | |
[PATCH] md: add write-intent-bitmap support to raid5
Most awkward part of this is delaying write requests until bitmap updates have
been flushed.
To achieve this, we have a sequence number (seq_flush) which is incremented
each time the raid5 is unplugged.
If the raid thread notices that this has changed, it flushes bitmap changes,
and assigned the value of seq_flush to seq_write.
When a write request arrives, it is given the number from seq_write, and that
write request may not complete until seq_flush is larger than the saved seq
number.
We have a new queue for storing stripes which are waiting for a bitmap flush
and an extra flag for stripes to record if the write was 'degraded' and so
should not clear the a bit in the bitmap.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/raid6main.c')
0 files changed, 0 insertions, 0 deletions