zfs/module
Richard Yao a765a34a31 Clean up zvol request processing to pass uio and fix porting regressions
In illumos-gate, `zvol_read` and `zvol_write` are both passed uio_t
rather than bio_t. Since we are translating from bio to uio for both, we
might as well unify the logic and have code more similar to its illumos
counterpart. At the same time, we can fix some regressions that occurred
versus the original code from illumos-gate.

We refactor zvol_write to take uio and also correct the
following problems:

1. We did `dnode_hold()` on each IO when we already had a hold.
2. We would attempt to send writes that exceeded `DMU_MAX_ACCESS` to the
DMU.
3. We could call `zil_commit()` twice. In this case, this is because
Linux uses the `->write` function to send flushes and can aggregate the
flush with a write. If a synchronous write occurred with the flush, we
effectively flushed twice when there is no need to do that.

zvol_read also suffers from the first two problems. Other platforms
suffer from the first, so we leave that for a second patch so that there
is a discrete patch for them to cherry-pick.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes #4316
2016-02-18 10:23:30 -08:00
..
avl Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
nvpair Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
unicode Support parallel build trees (VPATH builds) 2015-07-17 13:42:51 -07:00
zcommon Illumos 4929 - want prevsnap property 2016-01-11 11:58:26 -08:00
zfs Clean up zvol request processing to pass uio and fix porting regressions 2016-02-18 10:23:30 -08:00
zpios Add large block support to zpios(1) benchmark 2015-09-22 09:13:20 -07:00
.gitignore gitignore: anchor entries at their respective directory 2013-04-02 10:50:17 -07:00
Makefile.in Prevent rm modules.* when make install 2015-12-02 14:39:12 -08:00