[linux-cifs-client] [DFS support patchset: ] [4/5]: Provides DFS
shrinkable submounts functionality.
Q (Igor Mammedov)
qwerty0987654321 at mail.ru
Tue Dec 18 14:15:41 GMT 2007
Signed-off-by: Igor Mammedov <niallain at gmail.com>
---
fs/cifs/cifs_dfs_ref.c | 303 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/cifs_dfs_ref.h | 2 +
fs/cifs/cifsfs.c | 6 +
3 files changed, 311 insertions(+), 0 deletions(-)
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index 30b0ed1..441d520 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -21,12 +21,20 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/dcache.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/vfs.h>
+#include <linux/fs.h>
#include <keys/user-type.h>
#include <linux/key-type.h>
#include "cifsglob.h"
#include "cifsproto.h"
+#include "cifsfs.h"
#include "cifs_debug.h"
+LIST_HEAD(cifs_dfs_automount_list);
+
static int cifs_resolver_instantiate(struct key *key, const void *data,
size_t datalen)
{
@@ -118,4 +126,299 @@ cifs_resolve_server_name_to_ip(const char *unc, char **ip_addr) {
return rc;
}
+/*
+ * DFS functions
+ */
+
+static char *cifs_get_share_name(const char *node_name)
+{
+ int len;
+ char *UNC;
+ char *pSep;
+
+ len = strlen(node_name);
+ UNC = kmalloc(len+2 /*for term null and additional \ if it's missed */,
+ GFP_KERNEL);
+ if (!UNC)
+ return NULL;
+
+ /* get share name and server name */
+ if (node_name[1] != '\\') {
+ UNC[0] = '\\';
+ strncpy(UNC+1, node_name, len);
+ len++;
+ UNC[len] = 0;
+ } else {
+ strncpy(UNC, node_name, len);
+ UNC[len] = 0;
+ }
+
+ /* find server name end */
+ pSep = memchr(UNC+2, '\\', len-2);
+ if (!pSep) {
+ cERROR(1, ("%s: no server name end in node name: %s",
+ __FUNCTION__, node_name));
+ kfree(UNC);
+ return NULL;
+ }
+
+ /* find sharename end */
+ pSep++;
+ pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC));
+ if (!pSep) {
+ cERROR(1, ("%s:2 cant find share name in node name: %s",
+ __FUNCTION__, node_name));
+ kfree(UNC);
+ return NULL;
+ }
+ /* trim path up to sharename end
+ * * now we have share name in UNC */
+ *pSep = 0;
+ len = pSep-UNC;
+
+ return UNC;
+}
+
+
+struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
+ struct dentry *dentry, char *ref_unc)
+{
+ int rc;
+ struct cifs_sb_info *cifs_sb;
+ struct vfsmount *mnt = ERR_PTR(-ENOENT);
+ char *mountdata;
+ int md_len;
+ char *devname;
+ char *tkn_e;
+ char *srvIP = NULL;
+ char sep = ',';
+ int off, noff;
+
+ cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
+
+ if (cifs_sb->mountdata == NULL)
+ return ERR_PTR(-EINVAL);
+
+ devname = cifs_get_share_name(ref_unc);
+ rc = cifs_resolve_server_name_to_ip(devname, &srvIP);
+ if (rc != 0) {
+ kfree(devname);
+ cERROR(1, ("%s: failed to resolve server part of %s to IP",
+ __FUNCTION__, devname));
+ return ERR_PTR(rc);
+ }
+ md_len = strlen(cifs_sb->mountdata) + strlen(srvIP) +
+ strlen(ref_unc) + 3;
+ mountdata = kzalloc(md_len+1, GFP_KERNEL);
+
+ /* copy all options except of unc,ip,prefixpath */
+ off = 0;
+ if (strncmp(cifs_sb->mountdata, "sep=", 4) == 0) {
+ sep = cifs_sb->mountdata[4];
+ strncpy(mountdata, cifs_sb->mountdata, 5);
+ off += 5;
+ }
+ while ((tkn_e = strchr(cifs_sb->mountdata+off, sep))) {
+ noff = (tkn_e - (cifs_sb->mountdata+off)) + 1;
+ if (strnicmp(cifs_sb->mountdata+off, "unc=", 4) == 0) {
+ off += noff;
+ continue;
+ }
+ if (strnicmp(cifs_sb->mountdata+off, "ip=", 3) == 0) {
+ off += noff;
+ continue;
+ }
+ if (strnicmp(cifs_sb->mountdata+off, "prefixpath=", 3) == 0) {
+ off += noff;
+ continue;
+ }
+ strncat(mountdata, cifs_sb->mountdata+off, noff);
+ off += noff;
+ }
+ strcat(mountdata, cifs_sb->mountdata+off);
+ mountdata[md_len] = '\0';
+ strcat(mountdata, ",ip=");
+ strcat(mountdata, srvIP);
+ strcat(mountdata, ",unc=");
+ strcat(mountdata, devname);
+ /* find prefixpath */
+ tkn_e = strchr(ref_unc+2, '\\');
+ if (tkn_e) {
+ tkn_e = strchr(tkn_e+1, '\\');
+ if (tkn_e) {
+ strcat(mountdata, ",prefixpath=");
+ strcat(mountdata, tkn_e);
+ }
+ }
+
+ /*cFYI(1,("%s: old mountdata: %s", __FUNCTION__,cifs_sb->mountdata));*/
+ /*cFYI(1, ("%s: new mountdata: %s", __FUNCTION__, mountdata ));*/
+
+ mnt = vfs_kern_mount(&cifs_fs_type, 0, devname, mountdata);
+ kfree(srvIP);
+ kfree(devname);
+ kfree(mountdata);
+ return mnt;
+
+}
+
+static char *build_full_dfs_path_from_dentry(struct dentry *dentry)
+{
+ char *full_path = NULL;
+ char *search_path;
+ char *tmp_path;
+ size_t l_max_len;
+ struct cifs_sb_info *cifs_sb;
+
+ if (dentry->d_inode == NULL)
+ return NULL;
+
+ cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
+
+ if (cifs_sb->tcon == NULL)
+ return NULL;
+
+ search_path = build_path_from_dentry(dentry);
+ if (search_path == NULL)
+ return NULL;
+
+ if (cifs_sb->tcon->Flags & 0x2) {
+ /* we should use full path name to correct working with DFS */
+ l_max_len = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE+1) +
+ strnlen(search_path, MAX_PATHCONF) + 1;
+ tmp_path = kmalloc(l_max_len, GFP_KERNEL);
+ if (tmp_path == NULL) {
+ kfree(search_path);
+ return NULL;
+ }
+ strncpy(tmp_path, cifs_sb->tcon->treeName, l_max_len);
+ strcat(tmp_path, search_path);
+ tmp_path[l_max_len-1] = 0;
+ full_path = tmp_path;
+ kfree(search_path);
+ } else {
+ full_path = search_path;
+ }
+ return full_path;
+}
+
+static void*
+cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
+{
+ struct dfs_info3_param *referrals = NULL;
+ unsigned int num_referrals = 0;
+ struct cifs_sb_info *cifs_sb;
+ struct cifsSesInfo *ses;
+ char *full_path = NULL;
+ int xid, i;
+ int rc = 0;
+ struct vfsmount *mnt = ERR_PTR(-ENOENT);
+
+ cFYI(1, ("in %s", __FUNCTION__));
+ BUG_ON(IS_ROOT(dentry));
+
+ xid = GetXid();
+
+ dput(nd->dentry);
+ nd->dentry = dget(dentry);
+ if (d_mountpoint(nd->dentry))
+ goto out_follow;
+
+ if (dentry->d_inode == NULL) {
+ rc = -EINVAL;
+ goto out_err;
+ }
+
+ cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
+ ses = cifs_sb->tcon->ses;
+
+ if (!ses) {
+ rc = -EINVAL;
+ goto out_err;
+ }
+
+ full_path = build_full_dfs_path_from_dentry(dentry);
+ if (full_path == NULL) {
+ rc = -ENOMEM;
+ goto out_err;
+ }
+
+ rc = get_dfs_path(xid, ses , full_path, cifs_sb->local_nls,
+ &num_referrals, &referrals,
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+
+ for (i = 0; i < num_referrals; i++) {
+ cFYI(1, ("%s: ref path: %s", __FUNCTION__,
+ referrals[i].path_name));
+ cFYI(1, ("%s: node path: %s", __FUNCTION__,
+ referrals[i].node_name));
+ cFYI(1, ("%s: fl: %hd, srv_type: %hd",
+ __FUNCTION__, referrals[i].flags,
+ referrals[i].server_type));
+ cFYI(1, ("%s: ref_flags: %hd, path_consumed: %hd",
+ __FUNCTION__,
+ referrals[i].ref_flag,
+ referrals[i].PathConsumed));
+
+ /* connect to storage node */
+ if (referrals[i].flags & DFSREF_STORAGE_SERVER) {
+ int len;
+ len = strlen(referrals[i].node_name);
+ if (len < 2) {
+ cERROR(1, ("%s: Net Address path too short: %s",
+ __FUNCTION__, referrals[i].node_name));
+ rc = -EINVAL;
+ goto out_err;
+ } else {
+ mnt = cifs_dfs_do_refmount(nd->mnt,
+ nd->dentry,
+ referrals[i].node_name);
+ cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
+ __FUNCTION__,
+ referrals[i].node_name, mnt));
+ if (!rc) {
+ /* have server so stop here & return */
+ break;
+ }
+ }
+ }
+ }
+
+ rc = PTR_ERR(mnt);
+ if (IS_ERR(mnt))
+ goto out_err;
+
+ mntget(mnt);
+ rc = do_add_mount(mnt, nd, nd->mnt->mnt_flags,
+ &cifs_dfs_automount_list);
+ if (rc < 0) {
+ mntput(mnt);
+ if (rc == -EBUSY)
+ goto out_follow;
+ goto out_err;
+ }
+ mntput(nd->mnt);
+ dput(nd->dentry);
+ nd->mnt = mnt;
+ nd->dentry = dget(mnt->mnt_root);
+
+out:
+ FreeXid(xid);
+ free_dfs_info_array(referrals, num_referrals);
+ cFYI(1, ("leaving %s" , __FUNCTION__));
+ return ERR_PTR(rc);
+out_err:
+ kfree(full_path);
+ path_release(nd);
+ goto out;
+out_follow:
+ /* BB ??? */
+ while (d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry)) ;
+ rc = 0;
+ goto out;
+}
+
+struct inode_operations cifs_dfs_referral_inode_operations = {
+ .follow_link = cifs_dfs_follow_mountpoint,
+};
diff --git a/fs/cifs/cifs_dfs_ref.h b/fs/cifs/cifs_dfs_ref.h
index 312a0bb..6b8b31f 100644
--- a/fs/cifs/cifs_dfs_ref.h
+++ b/fs/cifs/cifs_dfs_ref.h
@@ -24,6 +24,8 @@
#ifdef __KERNEL__
extern struct key_type key_type_cifs_resolver;
+extern struct list_head cifs_dfs_automount_list;
+extern struct inode_operations cifs_dfs_referral_inode_operations;
#endif /* KERNEL */
#endif /* _CIFS_DFS_REF_H */
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index b459e47..7e8e356 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -471,6 +471,12 @@ static void cifs_umount_begin(struct vfsmount *vfsmnt, int flags)
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *tcon;
+#ifdef CONFIG_CIFS_DFS_UPCALL
+ mark_mounts_for_expiry(&cifs_dfs_automount_list);
+ mark_mounts_for_expiry(&cifs_dfs_automount_list);
+ shrink_submounts(vfsmnt, &cifs_dfs_automount_list);
+#endif
+
if (!(flags & MNT_FORCE))
return;
cifs_sb = CIFS_SB(vfsmnt->mnt_sb);
--
1.5.3.7
More information about the linux-cifs-client
mailing list