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author | NeilBrown | 2017-03-15 04:05:12 +0100 |
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committer | Shaohua Li | 2017-03-23 03:15:57 +0100 |
commit | 16d997b78b157315f5c90fcbc2f9ce575cb3879f (patch) | |
tree | ae10253861afd7ce27aae967a4cf075f4b2621af /drivers/md/raid5-log.h | |
parent | md/raid5: use md_write_start to count stripes, not bios (diff) | |
download | kernel-qcow2-linux-16d997b78b157315f5c90fcbc2f9ce575cb3879f.tar.gz kernel-qcow2-linux-16d997b78b157315f5c90fcbc2f9ce575cb3879f.tar.xz kernel-qcow2-linux-16d997b78b157315f5c90fcbc2f9ce575cb3879f.zip |
md/raid5: simplfy delaying of writes while metadata is updated.
If a device fails during a write, we must ensure the failure is
recorded in the metadata before the completion of the write is
acknowleged.
Commit c3cce6cda162 ("md/raid5: ensure device failure recorded before
write request returns.") added code for this, but it was
unnecessarily complicated. We already had similar functionality for
handling updates to the bad-block-list, thanks to Commit de393cdea66c
("md: make it easier to wait for bad blocks to be acknowledged.")
So revert most of the former commit, and instead avoid collecting
completed writes if MD_CHANGE_PENDING is set. raid5d() will then flush
the metadata and retry the stripe_head.
As this change can leave a stripe_head ready for handling immediately
after handle_active_stripes() returns, we change raid5_do_work() to
pause when MD_CHANGE_PENDING is set, so that it doesn't spin.
We check MD_CHANGE_PENDING *after* analyse_stripe() as it could be set
asynchronously. After analyse_stripe(), we have collected stable data
about the state of devices, which will be used to make decisions.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid5-log.h')
0 files changed, 0 insertions, 0 deletions