[PATCH] vfs: parse sloppy mount option in correct order

[Ian Kent <raven@themaw.net>]

From: Roberto Bergantinos Corpas <rbergant@redhat.com>

With addition of fs_context support, options string is parsed
sequentially, if 'sloppy' option is not leftmost one, we may
return ENOPARAM to userland if a non-valid option preceeds sloopy
and mount will fail :

host# mount -o quota,sloppy 172.23.1.225:/share /mnt
mount.nfs: an incorrect mount option was specified
host# mount -o sloppy,quota 172.23.1.225:/share /mnt
host#

This patch correct that behaviour so that sloppy takes precedence
if specified anywhere on the string

changes since v1:
- add a boolean to fs context and postpone error reporting until
  parsing is done.

Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
---
 fs/cifs/fs_context.c       |    4 ++--
 fs/cifs/fs_context.h       |    1 -
 fs/fs_context.c            |   14 ++++++++++++--
 fs/nfs/fs_context.c        |    5 +++--
 fs/nfs/internal.h          |    1 -
 include/linux/fs_context.h |    2 ++
 6 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 0e13dec86b25..32c3fdd7d27a 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -864,7 +864,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 	if (!skip_parsing) {
 		opt = fs_parse(fc, smb3_fs_parameters, param, &result);
 		if (opt < 0)
-			return ctx->sloppy ? 1 : opt;
+			return fc->sloppy ? 1 : opt;
 	}
 
 	switch (opt) {
@@ -1420,7 +1420,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 		ctx->multiuser = true;
 		break;
 	case Opt_sloppy:
-		ctx->sloppy = true;
+		fc->sloppy = true;
 		break;
 	case Opt_nosharesock:
 		ctx->nosharesock = true;
diff --git a/fs/cifs/fs_context.h b/fs/cifs/fs_context.h
index bbaee4c2281f..75e4c41466fa 100644
--- a/fs/cifs/fs_context.h
+++ b/fs/cifs/fs_context.h
@@ -157,7 +157,6 @@ struct smb3_fs_context {
 	bool uid_specified;
 	bool cruid_specified;
 	bool gid_specified;
-	bool sloppy;
 	bool got_ip;
 	bool got_version;
 	bool got_rsize;
diff --git a/fs/fs_context.c b/fs/fs_context.c
index df04e5fc6d66..911a36bf2226 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -157,8 +157,15 @@ int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
 	if (ret != -ENOPARAM)
 		return ret;
 
-	return invalf(fc, "%s: Unknown parameter '%s'",
-		      fc->fs_type->name, param->key);
+	/* We got an invalid parameter, but sloppy may have been specified
+	 * later on param string.
+	 * Let's wait to process whole params to return EINVAL.
+	 */
+
+	fc->param_inval = true;
+	errorf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name, param->key);
+
+	return 0;
 }
 EXPORT_SYMBOL(vfs_parse_fs_param);
 
@@ -234,6 +241,9 @@ int generic_parse_monolithic(struct fs_context *fc, void *data)
 		}
 	}
 
+	if (!fc->sloppy && fc->param_inval)
+		ret = -EINVAL;
+
 	return ret;
 }
 EXPORT_SYMBOL(generic_parse_monolithic);
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 4da701fd1424..09da63cc84f7 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -485,7 +485,7 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
 
 	opt = fs_parse(fc, nfs_fs_parameters, param, &result);
 	if (opt < 0)
-		return (opt == -ENOPARAM && ctx->sloppy) ? 1 : opt;
+		return (opt == -ENOPARAM && fc->sloppy) ? 1 : opt;
 
 	if (fc->security)
 		ctx->has_sec_mnt_opts = 1;
@@ -853,7 +853,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
 		 * Special options
 		 */
 	case Opt_sloppy:
-		ctx->sloppy = true;
+		fc->sloppy = true;
+		dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
 		break;
 	}
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 898dd95bc7a7..83552def96f1 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -90,7 +90,6 @@ struct nfs_fs_context {
 	bool			internal;
 	bool			skip_reconfig_option_check;
 	bool			need_mount;
-	bool			sloppy;
 	unsigned int		flags;		/* NFS{,4}_MOUNT_* flags */
 	unsigned int		rsize, wsize;
 	unsigned int		timeo, retrans;
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index ff1375a16c8c..d91d42bc06ce 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -111,6 +111,8 @@ struct fs_context {
 	bool			need_free:1;	/* Need to call ops->free() */
 	bool			global:1;	/* Goes into &init_user_ns */
 	bool			oldapi:1;	/* Coming from mount(2) */
+	bool                    sloppy:1;       /* If fs support it and was specified */
+	bool                    param_inval:1;  /* If set, check sloppy value */
 };
 
 struct fs_context_operations {