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: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Pierguido Lambri <plambri@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 15261ba..f135f08 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -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);
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index cd8025a..c7b3c84 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -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,
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 1847aa8..851256e 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3765,7 +3765,8 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
/*
* 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;
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 789ff1d..2c227a9 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -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;
