cifs: Percolate error up to the caller during get/set acls [try #4]

Modify get/set_cifs_acl* calls to reutrn error code and percolate the
error code up to the caller.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsacl.c

@@ -560,7 +560,7 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
 	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 
 	if (IS_ERR(tlink))
-		return NULL;
+		return ERR_CAST(tlink);
 
 	xid = GetXid();
 	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
@@ -568,7 +568,9 @@ static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
 
 	cifs_put_tlink(tlink);
 
-	cFYI(1, "GetCIFSACL rc = %d ACL len %d", rc, *pacllen);
+	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
+	if (rc)
+		return ERR_PTR(rc);
 	return pntsd;
 }
 
@@ -583,7 +585,7 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
 	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 
 	if (IS_ERR(tlink))
-		return NULL;
+		return ERR_CAST(tlink);
 
 	tcon = tlink_tcon(tlink);
 	xid = GetXid();
@@ -591,18 +593,17 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
 	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, 0,
 			 &fid, &oplock, NULL, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
-	if (rc) {
-		cERROR(1, "Unable to open file to get ACL");
-		goto out;
+	if (!rc) {
+		rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
+		CIFSSMBClose(xid, tcon, fid);
 	}
 
-	rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
-	cFYI(1, "GetCIFSACL rc = %d ACL len %d", rc, *pacllen);
-
-	CIFSSMBClose(xid, tcon, fid);
- out:
 	cifs_put_tlink(tlink);
 	FreeXid(xid);
+
+	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
+	if (rc)
+		return ERR_PTR(rc);
 	return pntsd;
 }
 
@@ -695,7 +696,7 @@ static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 }
 
 /* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
-void
+int
 cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 		  struct inode *inode, const char *path, const __u16 *pfid)
 {
@@ -711,13 +712,17 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 		pntsd = get_cifs_acl(cifs_sb, inode, path, &acllen);
 
 	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
-	if (pntsd)
+	if (IS_ERR(pntsd)) {
+		rc = PTR_ERR(pntsd);
+		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
+	} else {
 		rc = parse_sec_desc(pntsd, acllen, fattr);
-	if (rc)
-		cFYI(1, "parse sec desc failed rc = %d", rc);
+		kfree(pntsd);
+		if (rc)
+			cERROR(1, "parse sec desc failed rc = %d", rc);
+	}
 
-	kfree(pntsd);
-	return;
+	return rc;
 }
 
 /* Convert mode bits to an ACL so we can update the ACL on the server */
@@ -736,7 +741,10 @@ int mode_to_acl(struct inode *inode, const char *path, __u64 nmode)
 	/* Add three ACEs for owner, group, everyone getting rid of
 	   other ACEs as chmod disables ACEs and set the security descriptor */
 
-	if (pntsd) {
+	if (IS_ERR(pntsd)) {
+		rc = PTR_ERR(pntsd);
+		cERROR(1, "%s: error %d getting sec desc", __func__, rc);
+	} else {
 		/* allocate memory for the smb header,
 		   set security descriptor request security descriptor
 		   parameters, and secuirty descriptor itself */

fs/cifs/cifsproto.h

@@ -130,7 +130,7 @@ extern int cifs_get_file_info_unix(struct file *filp);
 extern int cifs_get_inode_info_unix(struct inode **pinode,
 			const unsigned char *search_path,
 			struct super_block *sb, int xid);
-extern void cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
+extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
 			      struct cifs_fattr *fattr, struct inode *inode,
 			      const char *path, const __u16 *pfid);
 extern int mode_to_acl(struct inode *inode, const char *path, __u64);