Commit 5bb30a4d authored by Paulo Alcantara (SUSE)'s avatar Paulo Alcantara (SUSE) Committed by Steve French
Browse files

cifs: Fix retrieval of DFS referrals in cifs_mount() 



Make sure that DFS referrals are sent to newly resolved root targets
as in a multi tier DFS setup.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Link: https://lkml.kernel.org/r/05aa2995-e85e-0ff4-d003-5bb08bd17a22@canonical.com


Cc: stable@vger.kernel.org
Tested-by: default avatarMatthew Ruffell <matthew.ruffell@canonical.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 84a1f5b1

fs/cifs/connect.c

+22 −10
Original line number Diff line number Diff line
@@ -4786,6 +4786,17 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol, 
}



#ifdef CONFIG_CIFS_DFS_UPCALL

static inline void set_root_tcon(struct cifs_sb_info *cifs_sb,

				 struct cifs_tcon *tcon,

				 struct cifs_tcon **root)

{

	spin_lock(&cifs_tcp_ses_lock);

	tcon->tc_count++;

	tcon->remap = cifs_remap(cifs_sb);

	spin_unlock(&cifs_tcp_ses_lock);

	*root = tcon;

}



int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol)

{

	int rc = 0;
@@ -4887,18 +4898,10 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) 
	/* Cache out resolved root server */

	(void)dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),

			     root_path + 1, NULL, NULL);

	/*

	 * Save root tcon for additional DFS requests to update or create a new

	 * DFS cache entry, or even perform DFS failover.

	 */

	spin_lock(&cifs_tcp_ses_lock);

	tcon->tc_count++;

	tcon->dfs_path = root_path;

	kfree(root_path);

	root_path = NULL;

	tcon->remap = cifs_remap(cifs_sb);

	spin_unlock(&cifs_tcp_ses_lock);



	root_tcon = tcon;

	set_root_tcon(cifs_sb, tcon, &root_tcon);



	for (count = 1; ;) {

		if (!rc && tcon) {
@@ -4935,6 +4938,15 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) 
			mount_put_conns(cifs_sb, xid, server, ses, tcon);

			rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses,

					     &tcon);

			/*

			 * Ensure that DFS referrals go through new root server.

			 */

			if (!rc && tcon &&

			    (tcon->share_flags & (SHI1005_FLAGS_DFS |

						  SHI1005_FLAGS_DFS_ROOT))) {

				cifs_put_tcon(root_tcon);

				set_root_tcon(cifs_sb, tcon, &root_tcon);

			}

		}

		if (rc) {

			if (rc == -EACCES || rc == -EOPNOTSUPP)

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