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

8 files changed, 181 insertions, 76 deletions

diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index 26e07df783b9..c3bbd6af996d 100644
--- a/fs/9p/fid.h
+++ b/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;
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 9b0f0222e8bb..047c791427aa 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -71,19 +71,19 @@ 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;
@@ -91,19 +91,26 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
         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);
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 7d3a1018db52..a7d567192998 100644
--- a/fs/9p/v9fs.h
+++ b/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 *,
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 6248f0e727a3..97d3aed57983 100644
--- a/fs/9p/vfs_addr.c
+++ b/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
  *
  */
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 0924d4477da3..88e3787c6ea9 100644
--- a/fs/9p/vfs_dir.c
+++ b/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 ???
  *
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index a616fff8906d..0d55affe37d4 100644
--- a/fs/9p/vfs_file.c
+++ b/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
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 6a28842052ea..40fa807bd929 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -129,6 +129,12 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
         return res;
 }
 
+/**
+ * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
+ * @uflags: flags to convert
+ *
+ */
+
 int v9fs_uflags2omode(int uflags)
 {
         int ret;
@@ -312,6 +318,14 @@ error:
 }
 */
 
+/**
+ * v9fs_inode_from_fid - populate an inode by issuing a attribute request
+ * @v9ses: session information
+ * @fid: fid to issue attribute request for
+ * @sb: superblock on which to create inode
+ *
+ */
+
 static struct inode *
 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
         struct super_block *sb)
@@ -384,9 +398,12 @@ v9fs_open_created(struct inode *inode, struct file *file)
 
 /**
  * v9fs_create - Create a file
+ * @v9ses: session information
+ * @dir: directory that dentry is being created in
  * @dentry:  dentry that is being created
  * @perm: create permissions
  * @mode: open mode
+ * @extension: 9p2000.u extension string to support devices, etc.
  *
  */
 static struct p9_fid *
@@ -461,7 +478,7 @@ error:
 
 /**
  * v9fs_vfs_create - VFS hook to create files
- * @inode: directory inode that is being created
+ * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @mode: create permissions
  * @nd: path information
@@ -519,7 +536,7 @@ error:
 
 /**
  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
- * @inode:  inode that is being unlinked
+ * @dir:  inode that is being unlinked
  * @dentry: dentry that is being unlinked
  * @mode: mode for new directory
  *
@@ -703,9 +720,9 @@ done:
 
 /**
  * v9fs_vfs_getattr - retrieve file metadata
- * @mnt - mount information
- * @dentry - file to get attributes on
- * @stat - metadata structure to populate
+ * @mnt: mount information
+ * @dentry: file to get attributes on
+ * @stat: metadata structure to populate
  *
  */
 
@@ -928,7 +945,7 @@ done:
 /**
  * v9fs_vfs_readlink - read a symlink's location
  * @dentry: dentry for symlink
- * @buf: buffer to load symlink location into
+ * @buffer: buffer to load symlink location into
  * @buflen: length of buffer
  *
  */
@@ -996,10 +1013,12 @@ static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
  * v9fs_vfs_put_link - release a symlink path
  * @dentry: dentry for symlink
  * @nd: nameidata
+ * @p: unused
  *
  */
 
-static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
+static void
+v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
 {
         char *s = nd_get_link(nd);
 
@@ -1008,6 +1027,15 @@ static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void
                 __putname(s);
 }
 
+/**
+ * v9fs_vfs_mkspecial - create a special file
+ * @dir: inode to create special file in
+ * @dentry: dentry to create
+ * @mode: mode to create special file
+ * @extension: 9p2000.u format extension string representing special file
+ *
+ */
+
 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
         int mode, const char *extension)
 {
@@ -1037,7 +1065,7 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
  * @dentry: dentry for symlink
  * @symname: symlink data
  *
- * See 9P2000.u RFC for more information
+ * See Also: 9P2000.u RFC for more information
  *
  */
 
@@ -1058,10 +1086,6 @@ v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
  *
  */
 
-/* XXX - lots of code dup'd from symlink and creates,
- * figure out a better reuse strategy
- */
-
 static int
 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
               struct dentry *dentry)
@@ -1098,7 +1122,7 @@ clunk_fid:
  * @dir: inode destination for new link
  * @dentry: dentry for file
  * @mode: mode for creation
- * @dev_t: device associated with special file
+ * @rdev: device associated with special file
  *
  */
 
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index a452ac67fc94..bf59c3960494 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -75,6 +75,7 @@ static int v9fs_set_super(struct super_block *s, void *data)
  * v9fs_fill_super - populate superblock with info
  * @sb: superblock
  * @v9ses: session information
+ * @flags: flags propagated from v9fs_get_sb()
  *
  */
 
@@ -127,29 +128,26 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
         fid = v9fs_session_init(v9ses, dev_name, data);
         if (IS_ERR(fid)) {
                 retval = PTR_ERR(fid);
-                fid = NULL;
-                kfree(v9ses);
-                v9ses = NULL;
-                goto error;
+                goto close_session;
         }
 
         st = p9_client_stat(fid);
         if (IS_ERR(st)) {
                 retval = PTR_ERR(st);
-                goto error;
+                goto clunk_fid;
         }
 
         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
         if (IS_ERR(sb)) {
                 retval = PTR_ERR(sb);
-                goto error;
+                goto free_stat;
         }
         v9fs_fill_super(sb, v9ses, flags);
 
         inode = v9fs_get_inode(sb, S_IFDIR | mode);
         if (IS_ERR(inode)) {
                 retval = PTR_ERR(inode);
-                goto error;
+                goto release_sb;
         }
 
         inode->i_uid = uid;
@@ -158,7 +156,7 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
         root = d_alloc_root(inode);
         if (!root) {
                 retval = -ENOMEM;
-                goto error;
+                goto release_sb;
         }
 
         sb->s_root = root;
@@ -169,21 +167,22 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 
         return simple_set_mnt(mnt, sb);
 
-error:
-        kfree(st);
-        if (fid)
-                p9_client_clunk(fid);
-
-        if (v9ses) {
-                v9fs_session_close(v9ses);
-                kfree(v9ses);
-        }
-
+release_sb:
         if (sb) {
                 up_write(&sb->s_umount);
                 deactivate_super(sb);
         }
 
+free_stat:
+        kfree(st);
+
+clunk_fid:
+        p9_client_clunk(fid);
+
+close_session:
+        v9fs_session_close(v9ses);
+        kfree(v9ses);
+
         return retval;
 }