Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/ericvh/v9fs

* 'for-linus' of ssh://master.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: fix error path during early mount
  9p: make cryptic unknown error from server less scary
  9p: fix flags length in net
  9p: Correct fidpool creation failure in p9_client_create
  9p: use struct mutex instead of struct semaphore
  9p: propagate parse_option changes to client and transports
  fs/9p/v9fs.c (v9fs_parse_options): Handle kstrdup and match_strdup failure.
  9p: Documentation updates
  add match_strlcpy() us it to make v9fs make uname and remotename parsing more robust

fs/9p/fid.h

@@ -22,6 +22,21 @@
 
 #include <linux/list.h>
 
+/**
+ * struct v9fs_dentry - 9p private data stored in dentry d_fsdata
+ * @lock: protects the fidlist
+ * @fidlist: list of FIDs currently associated with this dentry
+ *
+ * This structure defines the 9p private data associated with
+ * a particular dentry.  In particular, this private data is used
+ * to lookup which 9P FID handle should be used for a particular VFS
+ * operation.  FID handles are associated with dentries instead of
+ * inodes in order to more closely map functionality to the Plan 9
+ * expected behavior for FID reclaimation and tracking.
+ *
+ * See Also: Mapping FIDs to Linux VFS model in
+ * Design and Implementation of the Linux 9P File System documentation
+ */
 struct v9fs_dentry {
 	spinlock_t lock; /* protect fidlist */
 	struct list_head fidlist;

fs/9p/v9fs.c

@@ -71,39 +71,46 @@ static match_table_t tokens = {
 
 /**
  * v9fs_parse_options - parse mount options into session structure
- * @options: options string passed from mount
  * @v9ses: existing v9fs session information
  *
+ * Return 0 upon success, -ERRNO upon failure.
  */
 
-static void v9fs_parse_options(struct v9fs_session_info *v9ses)
+static int v9fs_parse_options(struct v9fs_session_info *v9ses)
 {
 	char *options;
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
 	int option = 0;
 	char *s, *e;
-	int ret;
+	int ret = 0;
 
 	/* setup defaults */
 	v9ses->afid = ~0;
 	v9ses->debug = 0;
 	v9ses->cache = 0;
 
 	if (!v9ses->options)
-		return;
+		return 0;
 
 	options = kstrdup(v9ses->options, GFP_KERNEL);
+	if (!options) {
+		P9_DPRINTK(P9_DEBUG_ERROR,
+			   "failed to allocate copy of option string\n");
+		return -ENOMEM;
+	}
+
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
 		if (!*p)
 			continue;
 		token = match_token(p, tokens, args);
 		if (token < Opt_uname) {
-			ret = match_int(&args[0], &option);
-			if (ret < 0) {
+			int r = match_int(&args[0], &option);
+			if (r < 0) {
 				P9_DPRINTK(P9_DEBUG_ERROR,
 					"integer field, but no integer?\n");
+				ret = r;
 				continue;
 			}
 		}
@@ -125,10 +132,10 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 			v9ses->afid = option;
 			break;
 		case Opt_uname:
-			match_strcpy(v9ses->uname, &args[0]);
+			match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
 			break;
 		case Opt_remotename:
-			match_strcpy(v9ses->aname, &args[0]);
+			match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
 			break;
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
@@ -139,6 +146,13 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 
 		case Opt_access:
 			s = match_strdup(&args[0]);
+			if (!s) {
+				P9_DPRINTK(P9_DEBUG_ERROR,
+					   "failed to allocate copy"
+					   " of option argument\n");
+				ret = -ENOMEM;
+				break;
+			}
 			v9ses->flags &= ~V9FS_ACCESS_MASK;
 			if (strcmp(s, "user") == 0)
 				v9ses->flags |= V9FS_ACCESS_USER;
@@ -158,6 +172,7 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 		}
 	}
 	kfree(options);
+	return ret;
 }
 
 /**
@@ -173,6 +188,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 {
 	int retval = -EINVAL;
 	struct p9_fid *fid;
+	int rc;
 
 	v9ses->uname = __getname();
 	if (!v9ses->uname)
@@ -190,8 +206,21 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	v9ses->uid = ~0;
 	v9ses->dfltuid = V9FS_DEFUID;
 	v9ses->dfltgid = V9FS_DEFGID;
-	v9ses->options = kstrdup(data, GFP_KERNEL);
-	v9fs_parse_options(v9ses);
+	if (data) {
+		v9ses->options = kstrdup(data, GFP_KERNEL);
+		if (!v9ses->options) {
+			P9_DPRINTK(P9_DEBUG_ERROR,
+			   "failed to allocate copy of option string\n");
+			retval = -ENOMEM;
+			goto error;
+		}
+	}
+
+	rc = v9fs_parse_options(v9ses);
+	if (rc < 0) {
+		retval = rc;
+		goto error;
+	}
 
 	v9ses->clnt = p9_client_create(dev_name, v9ses->options);
 
@@ -233,7 +262,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	return fid;
 
 error:
-	v9fs_session_close(v9ses);
 	return ERR_PTR(retval);
 }
 
@@ -256,9 +284,12 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
 }
 
 /**
- * v9fs_session_cancel - mark transport as disconnected
- * 	and cancel all pending requests.
+ * v9fs_session_cancel - terminate a session
+ * @v9ses: session to terminate
+ *
+ * mark transport as disconnected and cancel all pending requests.
  */
+
 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
 	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 	p9_client_disconnect(v9ses->clnt);

fs/9p/v9fs.h

@@ -21,18 +21,69 @@
  *
  */
 
-/*
-  * Session structure provides information for an opened session
-  *
-  */
+/**
+ * enum p9_session_flags - option flags for each 9P session
+ * @V9FS_EXTENDED: whether or not to use 9P2000.u extensions
+ * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
+ * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
+ * @V9FS_ACCESS_ANY: use a single attach for all users
+ * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
+ *
+ * Session flags reflect options selected by users at mount time
+ */
+enum p9_session_flags {
+	V9FS_EXTENDED		= 0x01,
+	V9FS_ACCESS_SINGLE	= 0x02,
+	V9FS_ACCESS_USER	= 0x04,
+	V9FS_ACCESS_ANY		= 0x06,
+	V9FS_ACCESS_MASK	= 0x06,
+};
+
+/* possible values of ->cache */
+/**
+ * enum p9_cache_modes - user specified cache preferences
+ * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
+ * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
+ *
+ * eventually support loose, tight, time, session, default always none
+ */
+
+enum p9_cache_modes {
+	CACHE_NONE,
+	CACHE_LOOSE,
+};
+
+/**
+ * struct v9fs_session_info - per-instance session information
+ * @flags: session options of type &p9_session_flags
+ * @nodev: set to 1 to disable device mapping
+ * @debug: debug level
+ * @afid: authentication handle
+ * @cache: cache mode of type &p9_cache_modes
+ * @options: copy of options string given by user
+ * @uname: string user name to mount hierarchy as
+ * @aname: mount specifier for remote hierarchy
+ * @maxdata: maximum data to be sent/recvd per protocol message
+ * @dfltuid: default numeric userid to mount hierarchy as
+ * @dfltgid: default numeric groupid to mount hierarchy as
+ * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
+ * @clnt: reference to 9P network client instantiated for this session
+ * @debugfs_dir: reference to debugfs_dir which can be used for add'l debug
+ *
+ * This structure holds state for each session instance established during
+ * a sys_mount() .
+ *
+ * Bugs: there seems to be a lot of state which could be condensed and/or
+ * removed.
+ */
 
 struct v9fs_session_info {
 	/* options */
-	unsigned char flags;	/* session flags */
-	unsigned char nodev;	/* set to 1 if no disable device mapping */
-	unsigned short debug;	/* debug level */
-	unsigned int afid;	/* authentication fid */
-	unsigned int cache;	/* cache mode */
+	unsigned char flags;
+	unsigned char nodev;
+	unsigned short debug;
+	unsigned int afid;
+	unsigned int cache;
 
 	char *options;		/* copy of mount options */
 	char *uname;		/* user name to mount as */
@@ -45,22 +96,6 @@ struct v9fs_session_info {
 	struct dentry *debugfs_dir;
 };
 
-/* session flags */
-enum {
-	V9FS_EXTENDED		= 0x01,	/* 9P2000.u */
-	V9FS_ACCESS_MASK	= 0x06,	/* access mask */
-	V9FS_ACCESS_SINGLE	= 0x02,	/* only one user can access the files */
-	V9FS_ACCESS_USER	= 0x04,	/* attache per user */
-	V9FS_ACCESS_ANY		= 0x06,	/* use the same attach for all users */
-};
-
-/* possible values of ->cache */
-/* eventually support loose, tight, time, session, default always none */
-enum {
-	CACHE_NONE,		/* default */
-	CACHE_LOOSE,		/* no consistency */
-};
-
 extern struct dentry *v9fs_debugfs_root;
 
 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,

fs/9p/vfs_addr.c

@@ -43,7 +43,7 @@
 /**
  * v9fs_vfs_readpage - read an entire page in from 9P
  *
- * @file: file being read
+ * @filp: file being read
  * @page: structure to page
  *
  */

fs/9p/vfs_dir.c

@@ -60,7 +60,7 @@ static inline int dt_type(struct p9_stat *mistat)
 
 /**
  * v9fs_dir_readdir - read a directory
- * @filep: opened file structure
+ * @filp: opened file structure
  * @dirent: directory structure ???
  * @filldir: function to populate directory structure ???
  *

fs/9p/vfs_file.c

@@ -90,10 +90,11 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 
 /**
  * v9fs_file_lock - lock a file (or directory)
- * @inode: inode to be opened
- * @file: file being opened
+ * @filp: file to be locked
+ * @cmd: lock command
+ * @fl: file lock structure
  *
- * XXX - this looks like a local only lock, we should extend into 9P
+ * Bugs: this looks like a local only lock, we should extend into 9P
  *       by using open exclusive
  */
 
@@ -118,7 +119,7 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 
 /**
  * v9fs_file_read - read from a file
- * @filep: file pointer to read
+ * @filp: file pointer to read
  * @data: data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
@@ -142,7 +143,7 @@ v9fs_file_read(struct file *filp, char __user * data, size_t count,
 
 /**
  * v9fs_file_write - write to a file
- * @filep: file pointer to write
+ * @filp: file pointer to write
  * @data: data buffer to write data from
  * @count: size of buffer
  * @offset: offset at which to write data