add prefix to fs_context->log

... turning it into struct p_log embedded into fs_context.  Initialize
the prefix with fs_type->name, turning fs_parse() into a trivial
inline wrapper for __fs_parse().

This makes fs_parameter_description->name completely unused.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ceph/super.c

@@ -250,7 +250,7 @@ static int ceph_parse_source(struct fs_parameter *param, struct fs_context *fc)
 		dout("server path '%s'\n", fsopt->server_path);
 
 	ret = ceph_parse_mon_ips(param->string, dev_name_end - dev_name,
-				 pctx->copts, fc->log);
+				 pctx->copts, fc->log.log);
 	if (ret)
 		return ret;
 
@@ -268,7 +268,7 @@ static int ceph_parse_mount_param(struct fs_context *fc,
 	unsigned int mode;
 	int token, ret;
 
-	ret = ceph_parse_param(param, pctx->copts, fc->log);
+	ret = ceph_parse_param(param, pctx->copts, fc->log.log);
 	if (ret != -ENOPARAM)
 		return ret;
 

fs/fs_context.c

@@ -271,6 +271,7 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
 	fc->fs_type	= get_filesystem(fs_type);
 	fc->cred	= get_current_cred();
 	fc->net_ns	= get_net(current->nsproxy->net_ns);
+	fc->log.prefix	= fs_type->name;
 
 	mutex_init(&fc->uapi_mutex);
 
@@ -364,8 +365,8 @@ struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc)
 	get_net(fc->net_ns);
 	get_user_ns(fc->user_ns);
 	get_cred(fc->cred);
-	if (fc->log)
-		refcount_inc(&fc->log->usage);
+	if (fc->log.log)
+		refcount_inc(&fc->log.log->usage);
 
 	/* Can't call put until we've called ->dup */
 	ret = fc->ops->dup(fc, src_fc);
@@ -442,12 +443,12 @@ EXPORT_SYMBOL(logfc);
  */
 static void put_fc_log(struct fs_context *fc)
 {
-	struct fc_log *log = fc->log;
+	struct fc_log *log = fc->log.log;
 	int i;
 
 	if (log) {
 		if (refcount_dec_and_test(&log->usage)) {
-			fc->log = NULL;
+			fc->log.log = NULL;
 			for (i = 0; i <= 7; i++)
 				if (log->need_free & (1 << i))
 					kfree(log->buffer[i]);

fs/fs_parser.c

@@ -243,16 +243,6 @@ int __fs_parse(struct p_log *log,
 }
 EXPORT_SYMBOL(__fs_parse);
 
-int fs_parse(struct fs_context *fc,
-	     const struct fs_parameter_description *desc,
-	     struct fs_parameter *param,
-	     struct fs_parse_result *result)
-{
-	struct p_log log = {.prefix = desc->name, .log = fc->log};
-	return __fs_parse(&log, desc, param, result);
-}
-EXPORT_SYMBOL(fs_parse);
-
 /**
  * fs_lookup_param - Look up a path referred to by a parameter
  * @fc: The filesystem context to log errors through.

fs/fsopen.c

@@ -25,7 +25,7 @@ static ssize_t fscontext_read(struct file *file,
 			      char __user *_buf, size_t len, loff_t *pos)
 {
 	struct fs_context *fc = file->private_data;
-	struct fc_log *log = fc->log;
+	struct fc_log *log = fc->log.log;
 	unsigned int logsize = ARRAY_SIZE(log->buffer);
 	ssize_t ret;
 	char *p;
@@ -97,11 +97,11 @@ static int fscontext_create_fd(struct fs_context *fc, unsigned int o_flags)
 
 static int fscontext_alloc_log(struct fs_context *fc)
 {
-	fc->log = kzalloc(sizeof(*fc->log), GFP_KERNEL);
-	if (!fc->log)
+	fc->log.log = kzalloc(sizeof(*fc->log.log), GFP_KERNEL);
+	if (!fc->log.log)
 		return -ENOMEM;
-	refcount_set(&fc->log->usage, 1);
-	fc->log->owner = fc->fs_type->owner;
+	refcount_set(&fc->log.log->usage, 1);
+	fc->log.log->owner = fc->fs_type->owner;
 	return 0;
 }
 

include/linux/fs_context.h

@@ -97,7 +97,7 @@ struct fs_context {
 	struct user_namespace	*user_ns;	/* The user namespace for this mount */
 	struct net		*net_ns;	/* The network namespace for this mount */
 	const struct cred	*cred;		/* The mounter's credentials */
-	struct fc_log		*log;		/* Logging buffer */
+	struct p_log		log;		/* Logging buffer */
 	const char		*source;	/* The source name (eg. dev path) */
 	void			*security;	/* Linux S&M options */
 	void			*s_fs_info;	/* Proposed s_fs_info */
@@ -189,7 +189,7 @@ struct fc_log {
 extern __attribute__((format(printf, 4, 5)))
 void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...);
 
-#define __logfc(fc, l, fmt, ...) logfc((fc)->log, NULL, \
+#define __logfc(fc, l, fmt, ...) logfc((fc)->log.log, NULL, \
 					l, fmt, ## __VA_ARGS__)
 #define __plog(p, l, fmt, ...) logfc((p)->log, (p)->prefix, \
 					l, fmt, ## __VA_ARGS__)

include/linux/fs_parser.h

@@ -78,10 +78,15 @@ extern int __fs_parse(struct p_log *log,
 		    const struct fs_parameter_description *desc,
 		    struct fs_parameter *value,
 		    struct fs_parse_result *result);
-extern int fs_parse(struct fs_context *fc,
+
+static inline int fs_parse(struct fs_context *fc,
 	     const struct fs_parameter_description *desc,
-		    struct fs_parameter *value,
-		    struct fs_parse_result *result);
+	     struct fs_parameter *param,
+	     struct fs_parse_result *result)
+{
+	return __fs_parse(&fc->log, desc, param, result);
+}
+
 extern int fs_lookup_param(struct fs_context *fc,
 			   struct fs_parameter *param,
 			   bool want_bdev,