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>

3 files changed, 50 insertions, 0 deletions

diff --git a/api/examples/gfapi.py b/api/examples/gfapi.py
index 7d7a5bab12d..8dfe2791d0c 100755
--- a/api/examples/gfapi.py
+++ b/api/examples/gfapi.py
@@ -98,6 +98,9 @@ class File(object):
         def write (self, data, flags=0):
                 return api.glfs_write(self.fd,data,len(data),flags)
 
+	def fallocate (self, mode, offset, len):
+		return api.glfs_fallocate(self.fd, mode, offset, len)
+
 class Dir(object):
 
         def __init__ (self, fd):
@@ -349,6 +352,16 @@ if __name__ == "__main__":
                         return False, "wrong listxattr value %s" % repr(xattrs)
                 return True, "listxattr worked"
 
+        def test_fallocate (vol, path, data):
+                mypath = path + ".io"
+                fd = vol.creat(mypath,os.O_WRONLY|os.O_EXCL,0644)
+                if not fd:
+                        return False, "creat error"
+		rc = fd.fallocate(0, 0, 1024)
+                if rc != 0:
+                        return False, "fallocate error"
+                return True, "fallocate worked"
+
         test_list = (
                 test_create_write,
                 test_open_read,
@@ -363,6 +376,7 @@ if __name__ == "__main__":
                 test_setxattr,
                 test_getxattr,
                 test_listxattr,
+		test_fallocate,
         )
 
         ok_to_fail = (
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index 66e7d69f14d..4bc0bb1b6d3 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -2632,6 +2632,40 @@ out:
 
 
 int
+glfs_fallocate (struct glfs_fd *glfd, int keep_size, off_t offset, size_t len)
+{
+	int              ret = -1;
+	xlator_t        *subvol = NULL;
+	fd_t		*fd = NULL;
+
+	__glfs_entry_fd (glfd);
+
+	subvol = glfs_active_subvol (glfd->fs);
+	if (!subvol) {
+		ret = -1;
+		errno = EIO;
+		goto out;
+	}
+
+	fd = glfs_resolve_fd (glfd->fs, subvol, glfd);
+	if (!fd) {
+		ret = -1;
+		errno = EBADFD;
+		goto out;
+	}
+
+	ret = syncop_fallocate (subvol, fd, keep_size, offset, len);
+out:
+	if (fd)
+		fd_unref(fd);
+
+	glfs_subvol_done (glfd->fs, subvol);
+
+	return ret;
+}
+
+
+int
 glfs_chdir (struct glfs *fs, const char *path)
 {
 	int              ret = -1;
diff --git a/api/src/glfs.h b/api/src/glfs.h
index f472ca4ea1e..3888a103eb9 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -448,6 +448,8 @@ int glfs_lremovexattr (glfs_t *fs, const char *path, const char *name);
 
 int glfs_fremovexattr (glfs_fd_t *fd, const char *name);
 
+int glfs_fallocate(glfs_fd_t *fd, int keep_size, off_t offset, size_t len);
+
 char *glfs_getcwd (glfs_t *fs, char *buf, size_t size);
 
 int glfs_chdir (glfs_t *fs, const char *path);