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  1. 10 4月, 2013 13 次提交
  3. 06 4月, 2013 24 次提交
  5. 05 4月, 2013 3 次提交
    • M
      dm cache: reduce bio front_pad size in writeback mode · 19b0092e
      由 Mike Snitzer 提交于 
      A recent patch to fix the dm cache target's writethrough mode extended
the bio's front_pad to include a 1056-byte struct dm_bio_details.
Writeback mode doesn't need this, so this patch reduces the
per_bio_data_size to 16 bytes in this case instead of 1096.

The dm_bio_details structure was added in "dm cache: fix writes to
cache device in writethrough mode" which fixed commit e2e74d61 ("dm
cache: fix race in writethrough implementation").  In writeback mode
we avoid allocating the writethrough-specific members of the
per_bio_data structure (the dm_bio_details structure included).
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      19b0092e
    • D
      dm cache: fix writes to cache device in writethrough mode · b844fe69
      由 Darrick J. Wong 提交于 
      The dm-cache writethrough strategy introduced by commit e2e74d61
("dm cache: fix race in writethrough implementation") issues a bio to
the origin device, remaps and then issues the bio to the cache device.
This more conservative in-series approach was selected to favor
correctness over performance (of the previous parallel writethrough).
However, this in-series implementation that reuses the same bio to write
both the origin and cache device didn't take into account that the block
layer's req_bio_endio() modifies a completing bio's bi_sector and
bi_size.  So the new writethrough strategy needs to preserve these bio
fields, and restore them before submission to the cache device,
otherwise nothing gets written to the cache (because bi_size is 0).

This patch adds a struct dm_bio_details field to struct per_bio_data,
and uses dm_bio_record() and dm_bio_restore() to ensure the bio is
restored before reissuing to the cache device.  Adding such a large
structure to the per_bio_data is not ideal but we can improve this
later, for now correctness is the important thing.

This problem initially went unnoticed because the dm-cache test-suite
uses a linear DM device for the dm-cache device's origin device.
Writethrough worked as expected because DM submits a *clone* of the
original bio, so the original bio which was reused for the cache was
never touched.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NJoe Thornber <ejt@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
      b844fe69
    • R
      MIPS: Delete definition of SA_RESTORER. · 80fa8181
      由 Ralf Baechle 提交于 
      SA_RESTORER used to be defined as 0x04000000 but only the O32 ABI ever
supported its use and no libc was using it, so the entire sa-restorer
functionality was removed with lmo commit 39bffc12c3580ab [Zap sa_restorer.]
for 2.5.48 retaining only the SA_RESTORER definition as a reminder to avoid
accidental reuse of the mask bit.

Upstream cdef9602fbf1871a43f0f1b5cea10dd0f275167d [signal: always clear
sa_restorer on execve] adds code that assumes sa_sigaction has an
sa_restorer field, if SA_RESTORER is defined which would break MIPS.
So remove the SA_RESTORER definition before the v3.8.4 merge.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
(cherry picked from commit 17da8d63add23830892ac4dc2cbb3b5d4ffb79a8)
      80fa8181