open-behind: propagate errors from ob_wake_cbk

If opening fd in background fails, then remember the error and
fail all further calls on the fd.

Use the newly introduced call_unwind_error() function from
call-stub cleanup to fail the future calls.

Change-Id: I3b09b7969c98d915abd56590a2777ce833b81813
BUG: 846240
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4521
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>
read-ahead: re-enable support for variable page size

Support for variable size page-size was disabled with the introduction
of fixed size iobufs. Since the introduction of variable sized iobufs
there is no reason to not have configurable page-size in read-ahead.

This patch enables necessary changes in the translator for configurable
page-size.

Change-Id: I677d70fef50641eb041269aca92a088b9d4961cc
BUG: 764204
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4526
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <raghavendra@gluster.com>
cli: Display option 'device vg' only when bd backend enabled

Change-Id: If61c237948f51d48305f4897b3f226eead10bae8
BUG: 912997
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-on: http://review.gluster.org/4555
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
performance/write-behind: guarantee non-overlapping concurrent writes

Maintain a list of writes (either written behind or SYNC) which are
currently "in progress" (i.e, STACK_WIND'ed towards server) and hold
off any new STACK_WIND of write (either written behind or SYNC) which
overlaps with any of the "in progress" writes.

This is a guarantee which AFR's eager-lock depends upon (though not
strictly a write-behind requirement)

Change-Id: Icedd0b51b440366a906dc9223d62b7fd6ef2ca03
BUG: 857673
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4551
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <raghavendra@gluster.com>
testcase for the open-behind xlator when open fails

Test if the fops which are put into a stub and are waiting for
the open to complete should be unwound with the error if open
call itself fails.

Change-Id: I8c363d98303a7df1a0ca9ea6ef207c7123fdd388
BUG: 846240
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/4553
Reviewed-by: Anand Avati <avati@redhat.com>
Tested-by: Anand Avati <avati@redhat.com>
syncop: Fixed indentation and whitespaces.

Change-Id: I90e496b5d5027ac702ab3804ba52f26d537812a0
BUG: 764890
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/4554
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>