Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: implement optional loose read cache
  9p: Use kthread_stop instead of sending a SIGKILL.

11 files changed, 89 insertions, 13 deletions

diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX
index 4dc28cc93503..571785887a4f 100644
--- a/Documentation/filesystems/00-INDEX
+++ b/Documentation/filesystems/00-INDEX
@@ -4,6 +4,8 @@ Exporting
 	- explanation of how to make filesystems exportable.
 Locking
 	- info on locking rules as they pertain to Linux VFS.
+9p.txt
+	- 9p (v9fs) is an implementation of the Plan 9 remote fs protocol.
 adfs.txt
 	- info and mount options for the Acorn Advanced Disc Filing System.
 afs.txt
@@ -82,8 +84,6 @@ udf.txt
 	- info and mount options for the UDF filesystem.
 ufs.txt
 	- info on the ufs filesystem.
-v9fs.txt
-	- v9fs is a Unix implementation of the Plan 9 9p remote fs protocol.
 vfat.txt
 	- info on using the VFAT filesystem used in Windows NT and Windows 95
 vfs.txt
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 4d075a4558f9..bbd8b28c13de 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -40,6 +40,10 @@ OPTIONS
   aname=name	aname specifies the file tree to access when the server is
   		offering several exported file systems.
 
+  cache=mode	specifies a cacheing policy.  By default, no caches are used.
+			loose = no attempts are made at consistency,
+                                intended for exclusive, read-only mounts
+
   debug=n	specifies debug level.  The debug level is a bitmask.
   			0x01 = display verbose error messages
 			0x02 = developer debug (DEBUG_CURRENT)
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index a9b6301a04fc..90419715c7e9 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -136,7 +136,8 @@ struct v9fs_fid *v9fs_fid_lookup(struct dentry *dentry)
 }
 
 /**
- * v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and release it
+ * v9fs_fid_clone - lookup the fid for a dentry, clone a private copy and
+ * 			release it
  * @dentry: dentry to look for fid in
  *
  * find a fid in the dentry and then clone to a new private fid
diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index 147ceef8e537..c783874a9caf 100644
--- a/fs/9p/mux.c
+++ b/fs/9p/mux.c
@@ -256,7 +256,7 @@ static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
 	vpt->muxnum--;
 	if (!vpt->muxnum) {
 		dprintk(DEBUG_MUX, "destroy proc %p\n", vpt);
-		send_sig(SIGKILL, vpt->task, 1);
+		kthread_stop(vpt->task);
 		vpt->task = NULL;
 		v9fs_mux_poll_task_num--;
 	}
@@ -438,11 +438,8 @@ static int v9fs_poll_proc(void *a)
 
 	vpt = a;
 	dprintk(DEBUG_MUX, "start %p %p\n", current, vpt);
-	allow_signal(SIGKILL);
 	while (!kthread_should_stop()) {
 		set_current_state(TASK_INTERRUPTIBLE);
-		if (signal_pending(current))
-			break;
 
 		list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
 			v9fs_poll_mux(m);
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index d9b561ba5e58..6ad6f192b6e4 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -53,6 +53,8 @@ enum {
 	Opt_uname, Opt_remotename,
 	/* Options that take no arguments */
 	Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
+	/* Cache options */
+	Opt_cache_loose,
 	/* Error token */
 	Opt_err
 };
@@ -76,6 +78,8 @@ static match_table_t tokens = {
 	{Opt_fd, "fd"},
 	{Opt_legacy, "noextend"},
 	{Opt_nodevmap, "nodevmap"},
+	{Opt_cache_loose, "cache=loose"},
+	{Opt_cache_loose, "loose"},
 	{Opt_err, NULL}
 };
 
@@ -106,6 +110,7 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
 	v9ses->debug = 0;
 	v9ses->rfdno = ~0;
 	v9ses->wfdno = ~0;
+	v9ses->cache = 0;
 
 	if (!options)
 		return;
@@ -121,7 +126,6 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
 					"integer field, but no integer?\n");
 				continue;
 			}
-
 		}
 		switch (token) {
 		case Opt_port:
@@ -169,6 +173,9 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
 			break;
+		case Opt_cache_loose:
+			v9ses->cache = CACHE_LOOSE;
+			break;
 		default:
 			continue;
 		}
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index c134d104cb28..820bf5ca35d8 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -47,7 +47,7 @@ struct v9fs_session_info {
 	unsigned int afid;	/* authentication fid */
 	unsigned int rfdno;	/* read file descriptor number */
 	unsigned int wfdno;	/* write file descriptor number */
-
+	unsigned int cache;	/* cache mode */
 
 	char *name;		/* user name to mount as */
 	char *remotename;	/* name of remote hierarchy being mounted */
@@ -73,6 +73,13 @@ enum {
 	PROTO_FD,
 };
 
+/* 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;
 
 int v9fs_session_init(struct v9fs_session_info *, const char *, char *);
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 450b0c1b385e..8ada4c5c5d70 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -40,8 +40,10 @@
 extern struct file_system_type v9fs_fs_type;
 extern const struct address_space_operations v9fs_addr_operations;
 extern const struct file_operations v9fs_file_operations;
+extern const struct file_operations v9fs_cached_file_operations;
 extern const struct file_operations v9fs_dir_operations;
 extern struct dentry_operations v9fs_dentry_operations;
+extern struct dentry_operations v9fs_cached_dentry_operations;
 
 struct inode *v9fs_get_inode(struct super_block *sb, int mode);
 ino_t v9fs_qid2ino(struct v9fs_qid *qid);
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index cc24abf232d5..bed48fa96521 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -63,6 +63,8 @@ static int v9fs_vfs_readpage(struct file *filp, struct page *page)
 	int total = 0;
 	int result = 0;
 
+	dprintk(DEBUG_VFS, "\n");
+
 	buffer = kmap(page);
 	do {
 		if (count < rsize)
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index 062daa6000ab..ddffd8aa902d 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -53,10 +53,31 @@
 static int v9fs_dentry_delete(struct dentry *dentry)
 {
 	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
+
 	return 1;
 }
 
 /**
+ * v9fs_cached_dentry_delete - called when dentry refcount equals 0
+ * @dentry:  dentry in question
+ *
+ * Only return 1 if our inode is invalid.  Only non-synthetic files
+ * (ones without mtime == 0) should be calling this function.
+ *
+ */
+
+static int v9fs_cached_dentry_delete(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
+
+	if(!inode)
+		return 1;
+
+	return 0;
+}
+
+/**
  * v9fs_dentry_release - called when dentry is going to be freed
  * @dentry:  dentry that is being release
  *
@@ -87,6 +108,11 @@ void v9fs_dentry_release(struct dentry *dentry)
 	}
 }
 
+struct dentry_operations v9fs_cached_dentry_operations = {
+	.d_delete = v9fs_cached_dentry_delete,
+	.d_release = v9fs_dentry_release,
+};
+
 struct dentry_operations v9fs_dentry_operations = {
 	.d_delete = v9fs_dentry_delete,
 	.d_release = v9fs_dentry_release,
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 6c78343cf690..653dfa5b2531 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -79,6 +79,13 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 	vfid->filp = file;
 	kfree(fcall);
 
+	if((vfid->qid.version) && (v9ses->cache)) {
+		dprintk(DEBUG_VFS, "cached");
+		/* enable cached file options */
+		if(file->f_op == &v9fs_file_operations)
+			file->f_op = &v9fs_cached_file_operations;
+	}
+
 	return 0;
 
 Clunk_Fid:
@@ -238,6 +245,17 @@ v9fs_file_write(struct file *filp, const char __user * data,
 	return total;
 }
 
+const struct file_operations v9fs_cached_file_operations = {
+	.llseek = generic_file_llseek,
+	.read = do_sync_read,
+	.aio_read = generic_file_aio_read,
+	.write = v9fs_file_write,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+	.lock = v9fs_file_lock,
+	.mmap = generic_file_mmap,
+};
+
 const struct file_operations v9fs_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_file_read,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 5cf22134826b..124a085d1f2e 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -504,7 +504,10 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 		goto error;
 	}
 
-	dentry->d_op = &v9fs_dentry_operations;
+	if(v9ses->cache)
+		dentry->d_op = &v9fs_cached_dentry_operations;
+	else
+		dentry->d_op = &v9fs_dentry_operations;
 	d_instantiate(dentry, inode);
 
 	if (nd && nd->flags & LOOKUP_OPEN) {
@@ -589,7 +592,10 @@ static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 		goto error;
 	}
 
-	dentry->d_op = &v9fs_dentry_operations;
+	if(v9ses->cache)
+		dentry->d_op = &v9fs_cached_dentry_operations;
+	else
+		dentry->d_op = &v9fs_dentry_operations;
 	d_instantiate(dentry, inode);
 	return 0;
 
@@ -626,7 +632,6 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 
 	sb = dir->i_sb;
 	v9ses = v9fs_inode2v9ses(dir);
-	dentry->d_op = &v9fs_dentry_operations;
 	dirfid = v9fs_fid_lookup(dentry->d_parent);
 
 	if(IS_ERR(dirfid))
@@ -697,6 +702,10 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 
 	fid->qid = fcall->params.rstat.stat.qid;
 	v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
+	if((fid->qid.version)&&(v9ses->cache))
+		dentry->d_op = &v9fs_cached_dentry_operations;
+	else
+		dentry->d_op = &v9fs_dentry_operations;
 
 	d_add(dentry, inode);
 	kfree(fcall);
@@ -1184,7 +1193,10 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
 		goto free_vfid;
 	}
 
-	dentry->d_op = &v9fs_dentry_operations;
+	if(v9ses->cache)
+		dentry->d_op = &v9fs_cached_dentry_operations;
+	else
+		dentry->d_op = &v9fs_dentry_operations;
 	d_instantiate(dentry, inode);
 	return 0;