[CIFS] Migrate from prefixpath logic
Steve French [Fri, 27 May 2011 03:50:55 +0000 (03:50 +0000)]
Now we point superblock to a server share root and set a root dentry
appropriately. This let us share superblock between mounts like
//server/sharename/foo/bar and //server/sharename/foo further.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>

Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifs_fs_sb.h
fs/cifs/cifsfs.c
fs/cifs/cifsglob.h
fs/cifs/cifsproto.h
fs/cifs/connect.c
fs/cifs/dir.c
fs/cifs/inode.c

index a9d5692..c96b44b 100644 (file)
@@ -56,8 +56,6 @@ struct cifs_sb_info {
        mode_t  mnt_file_mode;
        mode_t  mnt_dir_mode;
        unsigned int mnt_cifs_flags;
-       int     prepathlen;
-       char   *prepath; /* relative path under the share to mount to */
        char   *mountdata; /* options received at mount time or via DFS refs */
        struct backing_dev_info bdi;
        struct delayed_work prune_tlinks;
index 1d2a93c..46fdd55 100644 (file)
@@ -415,8 +415,6 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m)
                seq_printf(s, ",nocase");
        if (tcon->retry)
                seq_printf(s, ",hard");
-       if (cifs_sb->prepath)
-               seq_printf(s, ",prepath=%s", cifs_sb->prepath);
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
                seq_printf(s, ",posixpaths");
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)
@@ -530,6 +528,100 @@ static const struct super_operations cifs_super_ops = {
 #endif
 };
 
+/*
+ * Get root dentry from superblock according to prefix path mount option.
+ * Return dentry with refcount + 1 on success and NULL otherwise.
+ */
+static struct dentry *
+cifs_get_root(struct smb_vol *vol, struct super_block *sb)
+{
+       int xid, rc;
+       struct inode *inode;
+       struct qstr name;
+       struct dentry *dparent = NULL, *dchild = NULL, *alias;
+       struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+       unsigned int i, full_len, len;
+       char *full_path = NULL, *pstart;
+       char sep;
+
+       full_path = cifs_build_path_to_root(vol, cifs_sb,
+                                           cifs_sb_master_tcon(cifs_sb));
+       if (full_path == NULL)
+               return NULL;
+
+       cFYI(1, "Get root dentry for %s", full_path);
+
+       xid = GetXid();
+       sep = CIFS_DIR_SEP(cifs_sb);
+       dparent = dget(sb->s_root);
+       full_len = strlen(full_path);
+       full_path[full_len] = sep;
+       pstart = full_path + 1;
+
+       for (i = 1, len = 0; i <= full_len; i++) {
+               if (full_path[i] != sep || !len) {
+                       len++;
+                       continue;
+               }
+
+               full_path[i] = 0;
+               cFYI(1, "get dentry for %s", pstart);
+
+               name.name = pstart;
+               name.len = len;
+               name.hash = full_name_hash(pstart, len);
+               dchild = d_lookup(dparent, &name);
+               if (dchild == NULL) {
+                       cFYI(1, "not exists");
+                       dchild = d_alloc(dparent, &name);
+                       if (dchild == NULL) {
+                               dput(dparent);
+                               dparent = NULL;
+                               goto out;
+                       }
+               }
+
+               cFYI(1, "get inode");
+               if (dchild->d_inode == NULL) {
+                       cFYI(1, "not exists");
+                       inode = NULL;
+                       if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
+                               rc = cifs_get_inode_info_unix(&inode, full_path,
+                                                             sb, xid);
+                       else
+                               rc = cifs_get_inode_info(&inode, full_path,
+                                                        NULL, sb, xid, NULL);
+                       if (rc) {
+                               dput(dchild);
+                               dput(dparent);
+                               dparent = NULL;
+                               goto out;
+                       }
+                       alias = d_materialise_unique(dchild, inode);
+                       if (alias != NULL) {
+                               dput(dchild);
+                               if (IS_ERR(alias)) {
+                                       dput(dparent);
+                                       dparent = NULL;
+                                       goto out;
+                               }
+                               dchild = alias;
+                       }
+               }
+               cFYI(1, "parent %p, child %p", dparent, dchild);
+
+               dput(dparent);
+               dparent = dchild;
+               len = 0;
+               pstart = full_path + i + 1;
+               full_path[i] = sep;
+       }
+out:
+       _FreeXid(xid);
+       kfree(full_path);
+       return dparent;
+}
+
 static struct dentry *
 cifs_do_mount(struct file_system_type *fs_type,
              int flags, const char *dev_name, void *data)
@@ -585,7 +677,10 @@ cifs_do_mount(struct file_system_type *fs_type,
 
        sb->s_flags |= MS_ACTIVE;
 
-       root = dget(sb->s_root);
+       root = cifs_get_root(volume_info, sb);
+       if (root == NULL)
+               goto out_super;
+       cFYI(1, "dentry root is: %p", root);
        goto out;
 
 out_super:
index 30699d9..68ec457 100644 (file)
@@ -155,6 +155,61 @@ struct cifs_cred {
  *****************************************************************
  */
 
+struct smb_vol {
+       char *username;
+       char *password;
+       char *domainname;
+       char *UNC;
+       char *UNCip;
+       char *iocharset;  /* local code page for mapping to and from Unicode */
+       char source_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* clnt nb name */
+       char target_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* srvr nb name */
+       uid_t cred_uid;
+       uid_t linux_uid;
+       gid_t linux_gid;
+       mode_t file_mode;
+       mode_t dir_mode;
+       unsigned secFlg;
+       bool retry:1;
+       bool intr:1;
+       bool setuids:1;
+       bool override_uid:1;
+       bool override_gid:1;
+       bool dynperm:1;
+       bool noperm:1;
+       bool no_psx_acl:1; /* set if posix acl support should be disabled */
+       bool cifs_acl:1;
+       bool no_xattr:1;   /* set if xattr (EA) support should be disabled*/
+       bool server_ino:1; /* use inode numbers from server ie UniqueId */
+       bool direct_io:1;
+       bool strict_io:1; /* strict cache behavior */
+       bool remap:1;      /* set to remap seven reserved chars in filenames */
+       bool posix_paths:1; /* unset to not ask for posix pathnames. */
+       bool no_linux_ext:1;
+       bool sfu_emul:1;
+       bool nullauth:1;   /* attempt to authenticate with null user */
+       bool nocase:1;     /* request case insensitive filenames */
+       bool nobrl:1;      /* disable sending byte range locks to srv */
+       bool mand_lock:1;  /* send mandatory not posix byte range lock reqs */
+       bool seal:1;       /* request transport encryption on share */
+       bool nodfs:1;      /* Do not request DFS, even if available */
+       bool local_lease:1; /* check leases only on local system, not remote */
+       bool noblocksnd:1;
+       bool noautotune:1;
+       bool nostrictsync:1; /* do not force expensive SMBflush on every sync */
+       bool fsc:1;     /* enable fscache */
+       bool mfsymlinks:1; /* use Minshall+French Symlinks */
+       bool multiuser:1;
+       unsigned int rsize;
+       unsigned int wsize;
+       bool sockopt_tcp_nodelay:1;
+       unsigned short int port;
+       unsigned long actimeo; /* attribute cache timeout (jiffies) */
+       char *prepath;
+       struct sockaddr_storage srcaddr; /* allow binding to a local IP */
+       struct nls_table *local_nls;
+};
+
 struct TCP_Server_Info {
        struct list_head tcp_ses_list;
        struct list_head smb_ses_list;
@@ -517,6 +572,26 @@ static inline char CIFS_DIR_SEP(const struct cifs_sb_info *cifs_sb)
                return '\\';
 }
 
+static inline void
+convert_delimiter(char *path, char delim)
+{
+       int i;
+       char old_delim;
+
+       if (path == NULL)
+               return;
+
+       if (delim == '/')
+               old_delim = '\\';
+       else
+               old_delim = '/';
+
+       for (i = 0; path[i] != '\0'; i++) {
+               if (path[i] == old_delim)
+                       path[i] = delim;
+       }
+}
+
 #ifdef CONFIG_CIFS_STATS
 #define cifs_stats_inc atomic_inc
 
index eb3b58d..e41f607 100644 (file)
@@ -57,8 +57,9 @@ extern int init_cifs_idmap(void);
 extern void exit_cifs_idmap(void);
 extern void cifs_destroy_idmaptrees(void);
 extern char *build_path_from_dentry(struct dentry *);
-extern char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb,
-                                       struct cifsTconInfo *tcon);
+extern char *cifs_build_path_to_root(struct smb_vol *vol,
+                                    struct cifs_sb_info *cifs_sb,
+                                    struct cifsTconInfo *tcon);
 extern char *build_wildcard_path_from_dentry(struct dentry *direntry);
 extern char *cifs_compose_mount_options(const char *sb_mountdata,
                const char *fullpath, const struct dfs_info3_param *ref,
index 581654f..4956881 100644 (file)
 
 extern mempool_t *cifs_req_poolp;
 
-struct smb_vol {
-       char *username;
-       char *password;
-       char *domainname;
-       char *UNC;
-       char *UNCip;
-       char *iocharset;  /* local code page for mapping to and from Unicode */
-       char source_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* clnt nb name */
-       char target_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* srvr nb name */
-       uid_t cred_uid;
-       uid_t linux_uid;
-       gid_t linux_gid;
-       mode_t file_mode;
-       mode_t dir_mode;
-       unsigned secFlg;
-       bool retry:1;
-       bool intr:1;
-       bool setuids:1;
-       bool override_uid:1;
-       bool override_gid:1;
-       bool dynperm:1;
-       bool noperm:1;
-       bool no_psx_acl:1; /* set if posix acl support should be disabled */
-       bool cifs_acl:1;
-       bool no_xattr:1;   /* set if xattr (EA) support should be disabled*/
-       bool server_ino:1; /* use inode numbers from server ie UniqueId */
-       bool direct_io:1;
-       bool strict_io:1; /* strict cache behavior */
-       bool remap:1;      /* set to remap seven reserved chars in filenames */
-       bool posix_paths:1; /* unset to not ask for posix pathnames. */
-       bool no_linux_ext:1;
-       bool sfu_emul:1;
-       bool nullauth:1;   /* attempt to authenticate with null user */
-       bool nocase:1;     /* request case insensitive filenames */
-       bool nobrl:1;      /* disable sending byte range locks to srv */
-       bool mand_lock:1;  /* send mandatory not posix byte range lock reqs */
-       bool seal:1;       /* request transport encryption on share */
-       bool nodfs:1;      /* Do not request DFS, even if available */
-       bool local_lease:1; /* check leases only on local system, not remote */
-       bool noblocksnd:1;
-       bool noautotune:1;
-       bool nostrictsync:1; /* do not force expensive SMBflush on every sync */
-       bool fsc:1;     /* enable fscache */
-       bool mfsymlinks:1; /* use Minshall+French Symlinks */
-       bool multiuser:1;
-       unsigned int rsize;
-       unsigned int wsize;
-       bool sockopt_tcp_nodelay:1;
-       unsigned short int port;
-       unsigned long actimeo; /* attribute cache timeout (jiffies) */
-       char *prepath;
-       struct sockaddr_storage srcaddr; /* allow binding to a local IP */
-       struct nls_table *local_nls;
-};
-
 /* FIXME: should these be tunable? */
 #define TLINK_ERROR_EXPIRE     (1 * HZ)
 #define TLINK_IDLE_EXPIRE      (600 * HZ)
@@ -2569,12 +2514,6 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
                                        CIFS_MOUNT_POSIX_PATHS;
                }
 
-               /* We might be setting the path sep back to a different
-               form if we are reconnecting and the server switched its
-               posix path capability for this share */
-               if (sb && (CIFS_SB(sb)->prepathlen > 0))
-                       CIFS_SB(sb)->prepath[0] = CIFS_DIR_SEP(CIFS_SB(sb));
-
                if (sb && (CIFS_SB(sb)->rsize > 127 * 1024)) {
                        if ((cap & CIFS_UNIX_LARGE_READ_CAP) == 0) {
                                CIFS_SB(sb)->rsize = 127 * 1024;
@@ -2619,26 +2558,6 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
        }
 }
 
-static void
-convert_delimiter(char *path, char delim)
-{
-       int i;
-       char old_delim;
-
-       if (path == NULL)
-               return;
-
-       if (delim == '/')
-               old_delim = '\\';
-       else
-               old_delim = '/';
-
-       for (i = 0; path[i] != '\0'; i++) {
-               if (path[i] == old_delim)
-                       path[i] = delim;
-       }
-}
-
 void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
                        struct cifs_sb_info *cifs_sb)
 {
@@ -2659,18 +2578,6 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
                /* Windows ME may prefer this */
                cFYI(1, "readsize set to minimum: 2048");
        }
-       /* calculate prepath */
-       cifs_sb->prepath = pvolume_info->prepath;
-       if (cifs_sb->prepath) {
-               cifs_sb->prepathlen = strlen(cifs_sb->prepath);
-               /* we can not convert the / to \ in the path
-               separators in the prefixpath yet because we do not
-               know (until reset_cifs_unix_caps is called later)
-               whether POSIX PATH CAP is available. We normalize
-               the / to \ after reset_cifs_unix_caps is called */
-               pvolume_info->prepath = NULL;
-       } else
-               cifs_sb->prepathlen = 0;
        cifs_sb->mnt_uid = pvolume_info->linux_uid;
        cifs_sb->mnt_gid = pvolume_info->linux_gid;
        cifs_sb->mnt_file_mode = pvolume_info->file_mode;
@@ -2834,24 +2741,13 @@ build_unc_path_to_root(const struct smb_vol *volume_info,
        char *full_path;
 
        int unc_len = strnlen(volume_info->UNC, MAX_TREE_SIZE + 1);
-       full_path = kmalloc(unc_len + cifs_sb->prepathlen + 1, GFP_KERNEL);
+       full_path = kmalloc(unc_len + 1, GFP_KERNEL);
        if (full_path == NULL)
                return ERR_PTR(-ENOMEM);
 
        strncpy(full_path, volume_info->UNC, unc_len);
-       if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
-               int i;
-               for (i = 0; i < unc_len; i++) {
-                       if (full_path[i] == '\\')
-                               full_path[i] = '/';
-               }
-       }
-
-       if (cifs_sb->prepathlen)
-               strncpy(full_path + unc_len, cifs_sb->prepath,
-                               cifs_sb->prepathlen);
-
-       full_path[unc_len + cifs_sb->prepathlen] = 0; /* add trailing null */
+       full_path[unc_len] = 0; /* add trailing null */
+       convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
        return full_path;
 }
 
@@ -3049,10 +2945,6 @@ try_mount_again:
                CIFSSMBQFSAttributeInfo(xid, tcon);
        }
 
-       /* convert forward to back slashes in prepath here if needed */
-       if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
-               convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
-
        if ((tcon->unix_ext == 0) && (cifs_sb->rsize > (1024 * 127))) {
                cifs_sb->rsize = 1024 * 127;
                cFYI(DBG2, "no very large read support, rsize now 127K");
@@ -3082,10 +2974,10 @@ remote_path_check:
        }
 #endif
 
-       /* check if a whole path (including prepath) is not remote */
+       /* check if a whole path is not remote */
        if (!rc && tcon) {
                /* build_path_to_root works only when we have a valid tcon */
-               full_path = cifs_build_path_to_root(cifs_sb, tcon);
+               full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon);
                if (full_path == NULL) {
                        rc = -ENOMEM;
                        goto mount_fail_check;
@@ -3111,10 +3003,6 @@ remote_path_check:
                        rc = -ELOOP;
                        goto mount_fail_check;
                }
-               /* convert forward to back slashes in prepath here if needed */
-               if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
-                       convert_delimiter(cifs_sb->prepath,
-                                       CIFS_DIR_SEP(cifs_sb));
 
                rc = expand_dfs_referral(xid, pSesInfo, volume_info, cifs_sb,
                                         true);
@@ -3340,7 +3228,6 @@ cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb)
        struct rb_root *root = &cifs_sb->tlink_tree;
        struct rb_node *node;
        struct tcon_link *tlink;
-       char *tmp;
 
        cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
 
@@ -3357,11 +3244,6 @@ cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb)
        }
        spin_unlock(&cifs_sb->tlink_tree_lock);
 
-       tmp = cifs_sb->prepath;
-       cifs_sb->prepathlen = 0;
-       cifs_sb->prepath = NULL;
-       kfree(tmp);
-
        return 0;
 }
 
index 0521492..aa0669a 100644 (file)
@@ -50,7 +50,6 @@ build_path_from_dentry(struct dentry *direntry)
 {
        struct dentry *temp;
        int namelen;
-       int pplen;
        int dfsplen;
        char *full_path;
        char dirsep;
@@ -63,13 +62,12 @@ build_path_from_dentry(struct dentry *direntry)
                when the server crashed */
 
        dirsep = CIFS_DIR_SEP(cifs_sb);
-       pplen = cifs_sb->prepathlen;
        if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
                dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
        else
                dfsplen = 0;
 cifs_bp_rename_retry:
-       namelen = pplen + dfsplen;
+       namelen = dfsplen;
        for (temp = direntry; !IS_ROOT(temp);) {
                namelen += (1 + temp->d_name.len);
                temp = temp->d_parent;
@@ -100,7 +98,7 @@ cifs_bp_rename_retry:
                        return NULL;
                }
        }
-       if (namelen != pplen + dfsplen) {
+       if (namelen != dfsplen) {
                cERROR(1, "did not end path lookup where expected namelen is %d",
                        namelen);
                /* presumably this is only possible if racing with a rename
@@ -126,7 +124,6 @@ cifs_bp_rename_retry:
                        }
                }
        }
-       strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
        return full_path;
 }
 
index 5e278d3..53ea625 100644 (file)
@@ -735,10 +735,10 @@ static const struct inode_operations cifs_ipc_inode_ops = {
        .lookup = cifs_lookup,
 };
 
-char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb,
-                               struct cifsTconInfo *tcon)
+char *cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
+                             struct cifsTconInfo *tcon)
 {
-       int pplen = cifs_sb->prepathlen;
+       int pplen = vol->prepath ? strlen(vol->prepath) : 0;
        int dfsplen;
        char *full_path = NULL;
 
@@ -772,7 +772,7 @@ char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb,
                        }
                }
        }
-       strncpy(full_path + dfsplen, cifs_sb->prepath, pplen);
+       strncpy(full_path + dfsplen, vol->prepath, pplen);
        full_path[dfsplen + pplen] = 0; /* add trailing null */
        return full_path;
 }
@@ -884,19 +884,13 @@ struct inode *cifs_root_iget(struct super_block *sb)
        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
        struct inode *inode = NULL;
        long rc;
-       char *full_path;
        struct cifsTconInfo *tcon = cifs_sb_master_tcon(cifs_sb);
 
-       full_path = cifs_build_path_to_root(cifs_sb, tcon);
-       if (full_path == NULL)
-               return ERR_PTR(-ENOMEM);
-
        xid = GetXid();
        if (tcon->unix_ext)
-               rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
+               rc = cifs_get_inode_info_unix(&inode, "", sb, xid);
        else
-               rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
-                                               xid, NULL);
+               rc = cifs_get_inode_info(&inode, "", NULL, sb, xid, NULL);
 
        if (!inode) {
                inode = ERR_PTR(rc);
@@ -922,7 +916,6 @@ struct inode *cifs_root_iget(struct super_block *sb)
        }
 
 out:
-       kfree(full_path);
        /* can not call macro FreeXid here since in a void func
         * TODO: This is no longer true
         */