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, 40 insertions, 1 deletions

diff --git a/xlators/performance/md-cache/src/md-cache.c b/xlators/performance/md-cache/src/md-cache.c
index 24924200dae..0b2c94319fb 100644
--- a/xlators/performance/md-cache/src/md-cache.c
+++ b/xlators/performance/md-cache/src/md-cache.c
@@ -1849,6 +1849,44 @@ mdc_readdir (call_frame_t *frame, xlator_t *this, fd_t *fd,
 	return 0;
 }
 
+int
+mdc_fallocate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
+                  int32_t op_ret, int32_t op_errno,
+                  struct iatt *prebuf, struct iatt *postbuf, dict_t *xdata)
+{
+        mdc_local_t  *local = NULL;
+
+        local = frame->local;
+
+        if (op_ret != 0)
+                goto out;
+
+        if (!local)
+                goto out;
+
+        mdc_inode_iatt_set_validate(this, local->fd->inode, prebuf, postbuf);
+
+out:
+        MDC_STACK_UNWIND (fallocate, frame, op_ret, op_errno, prebuf, postbuf,
+                          xdata);
+
+        return 0;
+}
+
+int mdc_fallocate(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t mode,
+		  off_t offset, size_t len, dict_t *xdata)
+{
+	mdc_local_t *local;
+
+	local = mdc_local_get(frame);
+	local->fd = fd_ref(fd);
+
+	STACK_WIND(frame, mdc_fallocate_cbk, FIRST_CHILD(this),
+		   FIRST_CHILD(this)->fops->fallocate, fd, mode, offset, len,
+		   xdata);
+
+	return 0;
+}
 
 int
 mdc_forget (xlator_t *this, inode_t *inode)
@@ -1977,7 +2015,8 @@ struct xlator_fops fops = {
         .getxattr    = mdc_getxattr,
         .fgetxattr   = mdc_fgetxattr,
 	.readdirp    = mdc_readdirp,
-	.readdir     = mdc_readdir
+	.readdir     = mdc_readdir,
+	.fallocate   = mdc_fallocate,
 };