1 files changed, 411 insertions, 0 deletions
diff --git a/sys/fs/p9fs/p9fs_subr.c b/sys/fs/p9fs/p9fs_subr.c
new file mode 100644
index 000000000000..d0f04f6c5e97
--- /dev/null
+++ b/sys/fs/p9fs/p9fs_subr.c
@@ -0,0 +1,411 @@
+/*-
+ * Copyright (c) 2017 Juniper Networks, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+/*-
+ * 9P filesystem subroutines. This file consists of all the Non VFS subroutines.
+ * It contains all of the functions related to the driver submission which form
+ * the upper layer i.e, p9fs driver. This will interact with the client to make
+ * sure we have correct API calls in the header.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/systm.h>
+#include <sys/limits.h>
+#include <sys/mount.h>
+#include <sys/sysctl.h>
+#include <sys/vnode.h>
+
+#include "p9fs_proto.h"
+
+#include <fs/p9fs/p9_client.h>
+#include <fs/p9fs/p9_debug.h>
+#include <fs/p9fs/p9_protocol.h>
+#include <fs/p9fs/p9fs.h>
+
+int
+p9fs_proto_dotl(struct p9fs_session *vses)
+{
+
+	return (vses->flags & P9FS_PROTO_2000L);
+}
+
+/* Initialize a p9fs session */
+struct p9_fid *
+p9fs_init_session(struct mount *mp, int *error)
+{
+	struct p9fs_session *vses;
+	struct p9fs_mount *virtmp;
+	struct p9_fid *fid;
+	char *access;
+
+	virtmp = VFSTOP9(mp);
+	vses = &virtmp->p9fs_session;
+	vses->uid = P9_NONUNAME;
+	vses->uname = P9_DEFUNAME;
+	vses->aname = P9_DEFANAME;
+
+	/*
+	 * Create the client structure. Call into the driver to create
+	 * driver structures for the actual IO transfer.
+	 */
+	vses->clnt = p9_client_create(mp, error, virtmp->mount_tag);
+
+	if (vses->clnt == NULL) {
+		P9_DEBUG(ERROR, "%s: p9_client_create failed\n", __func__);
+		return (NULL);
+	}
+	/*
+	 * Find the client version and cache the copy. We will use this copy
+	 * throughout FS layer.
+	 */
+	if (p9_is_proto_dotl(vses->clnt))
+		vses->flags |= P9FS_PROTO_2000L;
+	else if (p9_is_proto_dotu(vses->clnt))
+		vses->flags |= P9FS_PROTO_2000U;
+
+	/* Set the access mode */
+	access = vfs_getopts(mp->mnt_optnew, "access", error);
+	if (access == NULL)
+		vses->flags |= P9_ACCESS_USER;
+	else if (!strcmp(access, "any"))
+		vses->flags |= P9_ACCESS_ANY;
+	else if (!strcmp(access, "single"))
+		vses->flags |= P9_ACCESS_SINGLE;
+	else if (!strcmp(access, "user"))
+		vses->flags |= P9_ACCESS_USER;
+	else {
+		P9_DEBUG(ERROR, "%s: unknown access mode\n", __func__);
+		*error = EINVAL;
+		goto out;
+	}
+
+	*error = 0;
+	/* Attach with the backend host*/
+	fid = p9_client_attach(vses->clnt, NULL, vses->uname, P9_NONUNAME,
+	    vses->aname, error);
+	vses->mnt_fid = fid;
+
+	if (*error != 0) {
+		P9_DEBUG(ERROR, "%s: attach failed: %d\n", __func__, *error);
+		goto out;
+	}
+	P9_DEBUG(SUBR, "%s: attach successful fid :%p\n", __func__, fid);
+	fid->uid = vses->uid;
+
+	/* initialize the node list for the session */
+	STAILQ_INIT(&vses->virt_node_list);
+	P9FS_LOCK_INIT(vses);
+
+	P9_DEBUG(SUBR, "%s: INIT session successful\n", __func__);
+
+	return (fid);
+out:
+	p9_client_destroy(vses->clnt);
+	return (NULL);
+}
+
+/* Begin to terminate a session */
+void
+p9fs_prepare_to_close(struct mount *mp)
+{
+	struct p9fs_session *vses;
+	struct p9fs_mount *vmp;
+	struct p9fs_node *np, *pnp, *tmp;
+
+	vmp = VFSTOP9(mp);
+	vses = &vmp->p9fs_session;
+
+	/* break the node->parent references */
+	STAILQ_FOREACH_SAFE(np, &vses->virt_node_list, p9fs_node_next, tmp) {
+		if (np->parent && np->parent != np) {
+			pnp = np->parent;
+			np->parent = NULL;
+			vrele(P9FS_NTOV(pnp));
+		}
+	}
+
+	/* We are about to teardown, we dont allow anything other than clunk after this.*/
+	p9_client_begin_disconnect(vses->clnt);
+}
+
+/* Shutdown a session */
+void
+p9fs_complete_close(struct mount *mp)
+{
+	struct p9fs_session *vses;
+	struct p9fs_mount *vmp;
+
+	vmp = VFSTOP9(mp);
+	vses = &vmp->p9fs_session;
+
+	/* Finish the close*/
+	p9_client_disconnect(vses->clnt);
+}
+
+
+/* Call from unmount. Close the session. */
+void
+p9fs_close_session(struct mount *mp)
+{
+	struct p9fs_session *vses;
+	struct p9fs_mount *vmp;
+
+	vmp = VFSTOP9(mp);
+	vses = &vmp->p9fs_session;
+
+	p9fs_complete_close(mp);
+	/* Clean up the clnt structure. */
+	p9_client_destroy(vses->clnt);
+	P9FS_LOCK_DESTROY(vses);
+	P9_DEBUG(SUBR, "%s: Clean close session .\n", __func__);
+}
+
+/*
+ * Remove all the fids of a particular type from a p9fs node
+ * as well as destroy/clunk them.
+ */
+void
+p9fs_fid_remove_all(struct p9fs_node *np, int leave_ofids)
+{
+	struct p9_fid *fid, *tfid;
+
+	STAILQ_FOREACH_SAFE(fid, &np->vfid_list, fid_next, tfid) {
+		STAILQ_REMOVE(&np->vfid_list, fid, p9_fid, fid_next);
+		p9_client_clunk(fid);
+	}
+
+	if (!leave_ofids) {
+		STAILQ_FOREACH_SAFE(fid, &np->vofid_list, fid_next, tfid) {
+			STAILQ_REMOVE(&np->vofid_list, fid, p9_fid, fid_next);
+			p9_client_clunk(fid);
+		}
+	}
+}
+
+
+/* Remove a fid from its corresponding fid list */
+void
+p9fs_fid_remove(struct p9fs_node *np, struct p9_fid *fid, int fid_type)
+{
+
+	switch (fid_type) {
+	case VFID:
+		P9FS_VFID_LOCK(np);
+		STAILQ_REMOVE(&np->vfid_list, fid, p9_fid, fid_next);
+		P9FS_VFID_UNLOCK(np);
+		break;
+	case VOFID:
+		P9FS_VOFID_LOCK(np);
+		STAILQ_REMOVE(&np->vofid_list, fid, p9_fid, fid_next);
+		P9FS_VOFID_UNLOCK(np);
+		break;
+	}
+}
+
+/* Add a fid to the corresponding fid list */
+void
+p9fs_fid_add(struct p9fs_node *np, struct p9_fid *fid, int fid_type)
+{
+
+	switch (fid_type) {
+	case VFID:
+		P9FS_VFID_LOCK(np);
+		STAILQ_INSERT_TAIL(&np->vfid_list, fid, fid_next);
+		P9FS_VFID_UNLOCK(np);
+		break;
+	case VOFID:
+		P9FS_VOFID_LOCK(np);
+		STAILQ_INSERT_TAIL(&np->vofid_list, fid, fid_next);
+		P9FS_VOFID_UNLOCK(np);
+		break;
+	}
+}
+
+/* Build the path from root to current directory */
+static int
+p9fs_get_full_path(struct p9fs_node *np, char ***names)
+{
+	int i, n;
+	struct p9fs_node *node;
+	char **wnames;
+
+	n = 0;
+	for (node = np ; (node != NULL) && !IS_ROOT(node) ; node = node->parent)
+		n++;
+
+	if (node == NULL)
+		return (0);
+
+	wnames = malloc(n * sizeof(char *), M_TEMP, M_ZERO|M_WAITOK);
+
+	for (i = n-1, node = np; i >= 0 ; i--, node = node->parent)
+		wnames[i] = node->inode.i_name;
+
+	*names = wnames;
+	return (n);
+}
+
+/*
+ * Return TRUE if this fid can be used for the requested mode.
+ */
+static int
+p9fs_compatible_mode(struct p9_fid *fid, int mode)
+{
+	/*
+	 * Return TRUE for an exact match. For OREAD and OWRITE, allow
+	 * existing ORDWR fids to match. Only check the low two bits
+	 * of mode.
+	 *
+	 * TODO: figure out if this is correct for O_APPEND
+	 */
+	int fid_mode = fid->mode & 3;
+	if (fid_mode == mode)
+		return (TRUE);
+	if (fid_mode == P9PROTO_ORDWR)
+		return (mode == P9PROTO_OREAD || mode == P9PROTO_OWRITE);
+	return (FALSE);
+}
+
+/*
+ * Retrieve fid structure corresponding to a particular
+ * uid and fid type for a p9fs node
+ */
+static struct p9_fid *
+p9fs_get_fid_from_uid(struct p9fs_node *np, uid_t uid, int fid_type, int mode)
+{
+	struct p9_fid *fid;
+
+	switch (fid_type) {
+	case VFID:
+		P9FS_VFID_LOCK(np);
+		STAILQ_FOREACH(fid, &np->vfid_list, fid_next) {
+			if (fid->uid == uid) {
+				P9FS_VFID_UNLOCK(np);
+				return (fid);
+			}
+		}
+		P9FS_VFID_UNLOCK(np);
+		break;
+	case VOFID:
+		P9FS_VOFID_LOCK(np);
+		STAILQ_FOREACH(fid, &np->vofid_list, fid_next) {
+			if (fid->uid == uid && p9fs_compatible_mode(fid, mode)) {
+				P9FS_VOFID_UNLOCK(np);
+				return (fid);
+			}
+		}
+		P9FS_VOFID_UNLOCK(np);
+		break;
+	}
+
+	return (NULL);
+}
+
+/*
+ * Function returns the fid sturcture for a file corresponding to current user id.
+ * First it searches in the fid list of the corresponding p9fs node.
+ * New fid will be created if not already present and added in the corresponding
+ * fid list in the p9fs node.
+ * If the user is not already attached then this will attach the user first
+ * and then create a new fid for this particular file by doing dir walk.
+ */
+struct p9_fid *
+p9fs_get_fid(struct p9_client *clnt, struct p9fs_node *np, struct ucred *cred,
+    int fid_type, int mode, int *error)
+{
+	uid_t uid;
+	struct p9_fid *fid, *oldfid;
+	struct p9fs_node *root;
+	struct p9fs_session *vses;
+	int i, l, clone;
+	char **wnames = NULL;
+	uint16_t nwnames;
+
+	oldfid = NULL;
+	vses = np->p9fs_ses;
+
+	if (vses->flags & P9_ACCESS_ANY)
+		uid = vses->uid;
+	else if (cred)
+		uid = cred->cr_uid;
+	else
+		uid = 0;
+
+	/*
+	 * Search for the fid in corresponding fid list.
+	 * We should return NULL for VOFID if it is not present in the list.
+	 * Because VOFID should have been created during the file open.
+	 * If VFID is not present in the list then we should create one.
+	 */
+	fid = p9fs_get_fid_from_uid(np, uid, fid_type, mode);
+	if (fid != NULL || fid_type == VOFID)
+		return (fid);
+
+	/* Check root if the user is attached */
+	root = &np->p9fs_ses->rnp;
+	fid = p9fs_get_fid_from_uid(root, uid, fid_type, mode);
+	if(fid == NULL) {
+		/* Attach the user */
+		fid = p9_client_attach(clnt, NULL, NULL, uid,
+		    vses->aname, error);
+		if (*error != 0)
+			return (NULL);
+		p9fs_fid_add(root, fid, fid_type);
+	}
+
+	/* If we are looking for root then return it */
+	if (IS_ROOT(np))
+		return (fid);
+
+	/* Get full path from root to p9fs node */
+	nwnames = p9fs_get_full_path(np, &wnames);
+
+	/*
+	 * Could not get full path.
+	 * If p9fs node is not deleted, parent should exist.
+	 */
+	KASSERT(nwnames != 0, ("%s: Directory of %s doesn't exist", __func__, np->inode.i_name));
+
+	clone = 1;
+	i = 0;
+	while (i < nwnames) {
+		l = MIN(nwnames - i, P9_MAXWELEM);
+
+		fid = p9_client_walk(fid, l, wnames, clone, error);
+		if (*error != 0) {
+			if (oldfid)
+				p9_client_clunk(oldfid);
+			fid = NULL;
+			goto bail_out;
+		}
+		oldfid = fid;
+		clone = 0;
+		i += l ;
+	}
+	p9fs_fid_add(np, fid, fid_type);
+bail_out:
+	free(wnames, M_TEMP);
+	return (fid);
+}