1 files changed, 308 insertions, 0 deletions
diff --git a/source3/modules/vfs_gpfs_prefetch.c b/source3/modules/vfs_gpfs_prefetch.c
new file mode 100644
index 0000000000..77f265fc24
--- /dev/null
+++ b/source3/modules/vfs_gpfs_prefetch.c
@@ -0,0 +1,308 @@
+/*
+   Unix SMB/CIFS implementation.
+   Make use of gpfs prefetch functionality
+
+   Copyright (C) Volker Lendecke 2008
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include "includes.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_VFS
+
+#include <gpfs.h>
+#include <gpfs_fcntl.h>
+
+static int (*gpfs_fcntl_fn)(int fd, void *arg);
+
+static int smbd_gpfs_fcntl(int fd, void *arg)
+{
+	static void *libgpfs_handle = NULL;
+
+	DEBUG(10, ("smbd_gpfs_fcntl called for %d\n", fd));
+
+	if (gpfs_fcntl_fn == NULL) {
+		libgpfs_handle = sys_dlopen("libgpfs.so", RTLD_LAZY);
+
+		if (libgpfs_handle == NULL) {
+			DEBUG(10, ("sys_dlopen for libgpfs failed: %s\n",
+				   strerror(errno)));
+			return;
+		}
+
+		gpfs_fcntl_fn = sys_dlsym(libgpfs_handle, "gpfs_fcntl");
+		if (gpfs_fcntl_fn == NULL) {
+			DEBUG(3, ("libgpfs.so does not contain the symbol "
+				  "'gpfs_fcntl'\n"));
+			errno = ENOSYS;
+			return -1;
+		}
+	}
+
+	return gpfs_fcntl_fn(fd, arg);
+}
+
+struct gpfs_prefetch_config {
+	name_compare_entry *namelist;
+	size_t size;
+};
+
+struct gpfs_prefetch_hints {
+	blksize_t st_blksize;
+	/*
+	 * The current center around which config->size bytes are
+	 * prefetched
+	 */
+	SMB_OFF_T center;
+};
+
+static void gpfs_prefetch_recenter(vfs_handle_struct *handle,
+				   files_struct *fsp,
+				   SMB_OFF_T offset, size_t size,
+				   struct gpfs_prefetch_hints *hints)
+{
+	int ret;
+	SMB_OFF_T new_center;
+
+	struct {
+		gpfsFcntlHeader_t hdr;
+		gpfsMultipleAccessRange_t acc;
+	} arg;
+
+
+	if (hints->st_blksize == 0) {
+		SMB_STRUCT_STAT sbuf;
+
+		if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
+			return;
+		}
+		DEBUG(10, ("gpfs_prefetch_recenter: st_blksize = %d\n",
+			   (int)sbuf.st_blksize));
+		hints->st_blksize = sbuf.st_blksize;
+	}
+
+	new_center = (offset > size) ? offset : 0;
+
+	DEBUG(10, ("gpfs_prefetch_recenter: size=%d, offset=%d, "
+		   "old_center=%d, new_center=%d\n", (int)size, (int)offset,
+		   (int)hints->center, (int)new_center));
+
+	ZERO_STRUCT(arg);
+
+	arg.hdr.totalLength = sizeof(arg);
+	arg.hdr.fcntlVersion = GPFS_FCNTL_CURRENT_VERSION;
+	arg.hdr.fcntlReserved = 0;
+	arg.acc.structLen = sizeof(arg.acc);
+	arg.acc.structType = GPFS_MULTIPLE_ACCESS_RANGE;
+	arg.acc.accRangeCnt = 1;
+	arg.acc.relRangeCnt = 1;
+
+	arg.acc.accRangeArray[0].blockNumber = new_center/hints->st_blksize;
+	arg.acc.accRangeArray[0].start = 0;
+	arg.acc.accRangeArray[0].length = size;
+	arg.acc.accRangeArray[0].isWrite = 0;
+
+	arg.acc.relRangeArray[0].blockNumber = hints->center/hints->st_blksize;
+	arg.acc.relRangeArray[0].start = 0;
+	arg.acc.relRangeArray[0].length = size;
+	arg.acc.relRangeArray[0].isWrite = 0;
+
+	ret = smbd_gpfs_fcntl(fsp->fh->fd, &arg);
+	if (ret == -1) {
+		DEBUG(5, ("gpfs_fcntl returned %s\n", strerror(errno)));
+	}
+
+	hints->center = new_center;
+}
+
+static ssize_t gpfs_prefetch_pread(vfs_handle_struct *handle,
+				   files_struct *fsp, void *data,
+				   size_t n, SMB_OFF_T offset)
+{
+	struct gpfs_prefetch_config *config =
+		(struct gpfs_prefetch_config *)handle->data;
+	struct gpfs_prefetch_hints *hints = (struct gpfs_prefetch_hints *)
+		VFS_FETCH_FSP_EXTENSION(handle, fsp);
+	SMB_OFF_T out_of_center;
+
+	/*
+	 * How far away from the center of the prefetch region is the
+	 * request?
+	 */
+
+	out_of_center = (offset > hints->center)
+		? (offset - hints->center) : (hints->center - offset);
+
+	DEBUG(10, ("gpfs_prefetch_pread: n=%d, offset=%d, center=%d, "
+		   "out_of_center=%d, size=%d\n", (int)n, (int)offset,
+		   (int)hints->center, (int)out_of_center,
+		   (int)config->size));
+	/*
+	 * Are we completely out of the prefetch range or less than
+	 * 10% at its borders?
+	 */
+
+	if ((out_of_center > config->size)
+	    || ((config->size - out_of_center) * 10 < config->size)) {
+		/*
+		 * Re-center the prefetch area
+		 */
+		gpfs_prefetch_recenter(handle, fsp, offset, config->size,
+				       hints);
+	}
+
+	return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
+}
+
+static int gpfs_prefetch_open(vfs_handle_struct *handle,  const char *fname,
+			      files_struct *fsp, int flags, mode_t mode)
+{
+	int fd, ret;
+	struct gpfs_prefetch_hints *hints;
+	struct gpfs_prefetch_config *config =
+		(struct gpfs_prefetch_config *)handle->data;
+
+	struct {
+		gpfsFcntlHeader_t hdr;
+		gpfsAccessRange_t acc;
+	} arg;
+
+	DEBUG(10, ("gpfs_prefetch_open called for %s, config=%p, "
+		   "config->namelist = %p, config->size=%d\n", fname,
+		   config, config->namelist, (int)config->size));
+
+	if (!is_in_path(fname, config->namelist,
+			handle->conn->case_sensitive)) {
+		DEBUG(10, ("gpfs_prefetch_open not in list: %s\n", fname));
+		return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
+	}
+
+	hints = (struct gpfs_prefetch_hints *)VFS_ADD_FSP_EXTENSION(
+		handle, fsp, struct gpfs_prefetch_hints);
+	if (hints == NULL) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	fd = SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
+	if (fd == -1) {
+		VFS_REMOVE_FSP_EXTENSION(handle, fsp);
+		return -1;
+	}
+
+	arg.hdr.totalLength = sizeof(arg);
+	arg.hdr.fcntlVersion = GPFS_FCNTL_CURRENT_VERSION;
+	arg.hdr.fcntlReserved = 0;
+	arg.acc.structLen = sizeof(arg.acc);
+	arg.acc.structType = GPFS_ACCESS_RANGE;
+	arg.acc.start = 0;
+	arg.acc.length = 1;
+	arg.acc.isWrite = 0;
+
+	ret = smbd_gpfs_fcntl(fd, &arg);
+	if (ret == -1) {
+		DEBUG(5, ("gpfs_fcntl returned %s\n", strerror(errno)));
+	}
+
+	hints->st_blksize = 0;
+	hints->center = 0;
+
+	return fd;
+}
+
+static void gpfs_prefetch_config_free(void **data)
+{
+	struct gpfs_prefetch_config **config =
+		(struct gpfs_prefetch_config **)data;
+
+	free_namearray((*config)->namelist);
+	TALLOC_FREE(*config);
+}
+
+static int gpfs_prefetch_connect(struct vfs_handle_struct *handle,
+				 const char *service,
+				 const char *user)
+{
+	struct gpfs_prefetch_config *config;
+	const char *mask;
+
+	config = talloc(handle, struct gpfs_prefetch_config);
+	if (config == NULL) {
+		DEBUG(0, ("talloc failed\n"));
+		errno = ENOMEM;
+		return -1;
+	}
+
+	mask = lp_parm_const_string(SNUM(handle->conn), "gpfs_prefetch",
+				    "mask", "");
+
+	set_namearray(&config->namelist, mask);
+	config->size = lp_parm_int(SNUM(handle->conn), "gpfs_prefetch",
+				   "size", 1024);
+
+	/*
+	 * The size calculations in the core routines assume that
+	 * config->size is the size from the center to the border of
+	 * the prefetched area. So we need to multiply by 1024/2 here
+	 * to get the whole prefetch area in kilobytes.
+	 */
+	config->size *= 1024/2;
+
+	SMB_VFS_HANDLE_SET_DATA(handle, config, gpfs_prefetch_config_free,
+				struct gpfs_prefetch_config, goto fail);
+
+	return SMB_VFS_NEXT_CONNECT(handle, service, user);
+
+fail:
+	free_namearray(config->namelist);
+	TALLOC_FREE(config);
+	return -1;
+}
+
+/* VFS operations structure */
+
+static vfs_op_tuple gpfs_prefetch_op_tuples[] = {
+
+	{SMB_VFS_OP(gpfs_prefetch_open),	SMB_VFS_OP_OPEN,
+	 SMB_VFS_LAYER_TRANSPARENT },
+	{SMB_VFS_OP(gpfs_prefetch_pread),	SMB_VFS_OP_PREAD,
+	 SMB_VFS_LAYER_TRANSPARENT },
+	{SMB_VFS_OP(gpfs_prefetch_connect),	SMB_VFS_OP_CONNECT,
+	 SMB_VFS_LAYER_TRANSPARENT },
+
+        { SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP }
+};
+
+/*
+ * When done properly upstream (GPL issue resolved), change this
+ * routine name to vfs_gpfs_prefetch_init!!
+ */
+
+NTSTATUS init_samba_module(void);
+NTSTATUS init_samba_module(void)
+{
+	NTSTATUS status;
+
+	DEBUG(10, ("vfs_gpfs_prefetch_init called\n"));
+
+	status = smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "gpfs_prefetch",
+				  gpfs_prefetch_op_tuples);
+	DEBUG(10, ("smb_register_vfs returned %s\n",
+		   nt_errstr(status)));
+
+	return status;
+}