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

23 files changed, 1014 insertions, 215 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;