Commit 374402a2 authored by Sachin Prabhu's avatar Sachin Prabhu Committed by Steve French
Browse files

cifs_get_root shouldn't use path with tree name 



When a server returns the optional flag SMB_SHARE_IS_IN_DFS in response
to a tree connect, cifs_build_path_to_root() will return a pathname
which includes the hostname. This causes problems with cifs_get_root()
which separates each component and does a lookup for each component of
the path which in this case will incorrectly include looking up the
hostname component as a path component.

We encountered a problem with dfs shares hosted by a Netapp. When
connecting to nodes pointed to by the DFS share. The tree connect for
these nodes return SMB_SHARE_IS_IN_DFS resulting failures in lookup
in cifs_get_root().

RH bz: 1373153
The patch was tested against a Netapp simulator and by a user using an
actual Netapp server.

Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
Reported-by: default avatarPierguido Lambri <plambri@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 39566443

fs/cifs/cifsfs.c

+1 −1
Original line number Diff line number Diff line
@@ -615,7 +615,7 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) 
		return dget(sb->s_root);



	full_path = cifs_build_path_to_root(vol, cifs_sb,

					    cifs_sb_master_tcon(cifs_sb));

				cifs_sb_master_tcon(cifs_sb), 0);

	if (full_path == NULL)

		return ERR_PTR(-ENOMEM);

fs/cifs/cifsproto.h

+2 −1
Original line number Diff line number Diff line
@@ -63,7 +63,8 @@ extern void exit_cifs_spnego(void); 
extern char *build_path_from_dentry(struct dentry *);

extern char *cifs_build_path_to_root(struct smb_vol *vol,

				     struct cifs_sb_info *cifs_sb,

				     struct cifs_tcon *tcon);

				     struct cifs_tcon *tcon,

				     int add_treename);

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,

fs/cifs/connect.c

+2 −1
Original line number Diff line number Diff line
@@ -3765,7 +3765,8 @@ remote_path_check: 
		/*

		 * cifs_build_path_to_root works only when we have a valid tcon

		 */

		full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon);

		full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon,

					tcon->Flags & SMB_SHARE_IS_IN_DFS);

		if (full_path == NULL) {

			rc = -ENOMEM;

			goto mount_fail_check;

fs/cifs/dir.c

+2 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ renew_parental_timestamps(struct dentry *direntry) 


char *

cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,

			struct cifs_tcon *tcon)

			struct cifs_tcon *tcon, int add_treename)

{

	int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;

	int dfsplen;
@@ -59,7 +59,7 @@ cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, 
		return full_path;

	}



	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)

	if (add_treename)

		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);

	else

		dfsplen = 0;

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