gluster: add fallocate fop support

Implement support for the fallocate file operation. fallocate
allocates blocks for a particular inode such that future writes
to the associated region of the file are guaranteed not to fail
with ENOSPC.

This patch adds fallocate support to the following areas:

	- libglusterfs
	- mount/fuse
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

BUG: 949242
Change-Id: Ice8e61351f9d6115c5df68768bc844abbf0ce8bd
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/4969
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/libglusterfs/src/syncop.c b/libglusterfs/src/syncop.c
index 8e5db41fda7..f57e8da5a72 100644
--- a/libglusterfs/src/syncop.c
+++ b/libglusterfs/src/syncop.c
@@ -1917,6 +1917,37 @@ syncop_access (xlator_t *subvol, loc_t *loc, int32_t mask)
 
 
 int
+syncop_fallocate_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                      int op_ret, int op_errno, struct iatt *prebuf,
+                      struct iatt *postbuf, dict_t *xdata)
+{
+	struct syncargs *args = NULL;
+
+        args = cookie;
+
+        args->op_ret   = op_ret;
+        args->op_errno = op_errno;
+
+        __wake (args);
+
+	return 0;
+}
+
+int
+syncop_fallocate(xlator_t *subvol, fd_t *fd, int32_t keep_size, off_t offset,
+		 size_t len)
+{
+        struct syncargs args = {0, };
+
+        SYNCOP (subvol, (&args), syncop_fallocate_cbk, subvol->fops->fallocate,
+                fd, keep_size, offset, len, NULL);
+
+        errno = args.op_errno;
+        return args.op_ret;
+}
+
+
+int
 syncop_lk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 	       int op_ret, int op_errno, struct gf_flock *flock,
 	       dict_t *xdata)