Currently EC tries to reopen fd's that have been opened while a brick
was down. This is done as part of regular write operations, just after
having acquired the locks, and it's sent as a sub-fop of the main write
fop.

There were two problems:

1. The reopen was attempted on all UP bricks, even if a previous lock
didn't succeed. This is incorrect because most probably the open will
fail.

2. If reopen is sent and fails, the error is propagated to the main
operation, causing it to fail when it shouldn't.

To fix this, we only attempt reopens on bricks where the current fop
owns a lock, and we prevent any error to be propagated to the main
fop.

To implement this behaviour an argument used to indicate the minimum
number of required answers has overloaded to also include some flags. To
make the change consistent, it has been necessary to rename the
argument, which means that a lot of files have been changed. However
there are no functional changes.

This change has also uncovered a problem in discard code, which didn't
correctely process requests of small sizes because no real discard fop
was being processed, only a write of 0's on some region. In this case
some fields of the fop remained uninitialized or with incorrect values.
To fix this, a new function has been created to simulate success on a
fop and it's used in the discard case.

Thanks to Pranith for providing a test script that has also detected an
issue in this patch. This patch includes a small modification of this
script to force data to be written into bricks before stopping them.

Backport of:
> Change-Id: If272343873369186c2fb8f43c1d9c52c3ea304ec
> BUG: bz#1699866
> Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

Change-Id: If272343873369186c2fb8f43c1d9c52c3ea304ec
Fixes: bz#1699917
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation <> in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR <srangana@redhat.com>

When compiling in other architectures there appear many warnings. Some
of them are actual problems that prevent gluster to work correctly on
those architectures.

Change-Id: Icdc7107a2bc2da662903c51910beddb84bdf03c0
fixes: bz#1632717
Signed-off-by: Xavi Hernandez <xhernandez@redhat.com>

Change-Id: Ia84cc24c8924e6d22d02ac15f611c10e26db99b4
Signed-off-by: Nigel Babu <nigelb@redhat.com>

{ec-heal|ec-combine|ec-helpers|ec-inode-read}.c

For const strings, just do compile time size calc instead of runtime.

Compile-tested only!

Change-Id: If92ba0a7a20f64b898d01c6e3b6708190ca93e04
updates: bz#1193929
Signed-off-by: Yaniv Kaul <ykaul@redhat.com>

Existing EC code doesn't try to heal the OpenFD to
avoid unnecessary healing of the data later.

Fix implements the healing of open FDs before
carrying out file operations on them by making an
attempt to open the FDs on required up nodes.

BUG: 1431955
Change-Id: Ib696f59c41ffd8d5678a484b23a00bb02764ed15
Signed-off-by: Sunil Kumar Acharya <sheggodu@redhat.com>

At the moment in EC, [f]getxattr operations wait to acquire a lock
while other operations are in progress even when it is in the same mount with a
lock on the file/directory. This happens because [f]getxattr operations
follow the model where the operation is wound on 'k' of the bricks and are
matched to make sure the data returned is same on all of them. This consistency
check requires that no other operations are on-going while [f]getxattr
operations are wound to the bricks. We can perform [f]getxattr in
another way as well, where we find the good_mask from the lock that is already
granted and wind the operation on any one of the good bricks and unwind the
answer after adjusting size/blocks to the parent xlator. Since we are taking
into account good_mask, the reply we get will either be before or after a
possible on-going operation. Using this method, the operation doesn't need to
depend on completion of on-going operations which could be taking long time (In
case of some slow disks and writes are in progress etc). Thus we reduce the
time to serve [f]getxattr requests.

I changed [f]getxattr to dispatch-one and added extra logic in
ec_link_has_lock_conflict() to not have any conflicts for fops with
EC_MINIMUM_ONE as fop->minimum to achieve the effect described above.
Modified scripts to make sure READ fop is received in EC to trigger heals.

Updates gluster/glusterfs#368
Change-Id: I3b4ebf89181c336b7b8d5471b0454f016cdaf296
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

Problem:
Ec at the moment sends one modification fop after another, so if some of
the disks become slow, for a while then the wait time for the writes that
are waiting in the queue becomes really bad.

Fix:
Allow parallel writes when possible. For this we need to make 3 changes.
1) Each fop now has range parameters they will be updating.
2) Xattrop is changed to handle parallel xattrop requests where some
   would be modifying just dirty xattr.
3) Fops that refer to size now take locks and update the locks.

Fixes #251
Change-Id: Ibc3c15372f91bbd6fb617f0d99399b3149fa64b2
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

This patch removes old functions to align offsets and sizes
to stripe size boundaries and adds new ones to offer more
possibilities.

The new functions are:

 * ec_adjust_offset_down()
     Aligns a given offset to a multiple of the stripe size
     equal or smaller than the initial one. It returns the
     size of the gap between the aligned offset and the given
     one.

 * ec_adjust_offset_up()
     Aligns a given offset to a multiple of the stripe size
     equal or greater than the initial one. It returns the
     size of the skipped region between the given offset and
     the aligned one. If an overflow happens, the returned
     valid has negative sign (but correct value) and the
     offset is set to the maximum value (not aligned).

 * ec_adjust_size_down()
     Aligns the given size to a multiple of the stripe size
     equal or smaller than the initial one. It returns the
     size of the missed region between the aligned size and
     the given one.

 * ec_adjust_size_up()
     Aligns the given size to a multiple of the stripe size
     equal or greater than the initial one. It returns the
     size of the gap between the given size and the aligned
     one. If an overflow happens, the returned value has
     negative sign (but correct value) and the size is set
     to the maximum value (not aligned).

These functions have been defined in ec-helpers.h as static
inline since they are very small and compilers can optimize
them (specially the 'scale' argument).

Change-Id: I4c91009ad02f76c73772034dfde27ee1c78a80d7
Signed-off-by: Xavier Hernandez <jahernan@redhat.com>

When a SEEK_HOLE was issued near to the end of file, sometimes an
offset beyond the end of file was returned. Another problem was that
using some offsets greater than the end of file returned successfully
instead of failing with ENXIO.

Change-Id: I238d2884ba02fd19a78116b0f8f8e8d6338fb3f5
BUG: 1449348
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: https://review.gluster.org/17228
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>