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: (22 commits)
  9p: fix sparse warnings in new xattr code
  fs/9p: remove sparse warning in vfs_inode
  fs/9p: destroy fid on failed remove
  fs/9p: Prevent parallel rename when doing fid_lookup
  fs/9p: Add support user. xattr
  net/9p: Implement TXATTRCREATE 9p call
  net/9p: Implement attrwalk 9p call
  9p: Implement LOPEN
  fs/9p: This patch implements TLCREATE for 9p2000.L protocol.
  9p: Implement TMKDIR
  9p: Implement TMKNOD
  9p: Define and implement TSYMLINK for 9P2000.L
  9p: Define and implement TLINK for 9P2000.L
  9p: Define and implement TLINK for 9P2000.L
  9p: Implement client side of setattr for 9P2000.L protocol.
  9p: getattr client implementation for 9P2000.L protocol.
  fs/9p: Pass the correct user credentials during attach
  net/9p: Handle the server returned error properly
  9p: readdir implementation for 9p2000.L
  9p: Make use of iounit for read/write
  ...

fs/9p/Makefile

@@ -8,6 +8,8 @@ obj-$(CONFIG_9P_FS) := 9p.o
 	vfs_dir.o \
 	vfs_dentry.o \
 	v9fs.o \
-	fid.o
+	fid.o  \
+	xattr.o \
+	xattr_user.o
 
 9p-$(CONFIG_9P_FSCACHE) += cache.o

fs/9p/fid.c

@@ -97,6 +97,34 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
 	return ret;
 }
 
+/*
+ * We need to hold v9ses->rename_sem as long as we hold references
+ * to returned path array. Array element contain pointers to
+ * dentry names.
+ */
+static int build_path_from_dentry(struct v9fs_session_info *v9ses,
+				  struct dentry *dentry, char ***names)
+{
+	int n = 0, i;
+	char **wnames;
+	struct dentry *ds;
+
+	for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent)
+		n++;
+
+	wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL);
+	if (!wnames)
+		goto err_out;
+
+	for (ds = dentry, i = (n-1); i >= 0; i--, ds = ds->d_parent)
+		wnames[i] = (char  *)ds->d_name.name;
+
+	*names = wnames;
+	return n;
+err_out:
+	return -ENOMEM;
+}
+
 /**
  * v9fs_fid_lookup - lookup for a fid, try to walk if not found
  * @dentry: dentry to look for fid in
@@ -112,7 +140,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 	int i, n, l, clone, any, access;
 	u32 uid;
 	struct p9_fid *fid, *old_fid = NULL;
-	struct dentry *d, *ds;
+	struct dentry *ds;
 	struct v9fs_session_info *v9ses;
 	char **wnames, *uname;
 
@@ -139,49 +167,62 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 	fid = v9fs_fid_find(dentry, uid, any);
 	if (fid)
 		return fid;
-
+	/*
+	 * we don't have a matching fid. To do a TWALK we need
+	 * parent fid. We need to prevent rename when we want to
+	 * look at the parent.
+	 */
+	down_read(&v9ses->rename_sem);
 	ds = dentry->d_parent;
 	fid = v9fs_fid_find(ds, uid, any);
-	if (!fid) { /* walk from the root */
-		n = 0;
-		for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent)
-			n++;
+	if (fid) {
+		/* Found the parent fid do a lookup with that */
+		fid = p9_client_walk(fid, 1, (char **)&dentry->d_name.name, 1);
+		goto fid_out;
+	}
+	up_read(&v9ses->rename_sem);
 
-		fid = v9fs_fid_find(ds, uid, any);
-		if (!fid) { /* the user is not attached to the fs yet */
-			if (access == V9FS_ACCESS_SINGLE)
-				return ERR_PTR(-EPERM);
+	/* start from the root and try to do a lookup */
+	fid = v9fs_fid_find(dentry->d_sb->s_root, uid, any);
+	if (!fid) {
+		/* the user is not attached to the fs yet */
+		if (access == V9FS_ACCESS_SINGLE)
+			return ERR_PTR(-EPERM);
 
-			if (v9fs_proto_dotu(v9ses))
+		if (v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses))
 				uname = NULL;
-			else
-				uname = v9ses->uname;
+		else
+			uname = v9ses->uname;
 
-			fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
-				v9ses->aname);
-
-			if (IS_ERR(fid))
-				return fid;
-
-			v9fs_fid_add(ds, fid);
-		}
-	} else /* walk from the parent */
-		n = 1;
+		fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
+				       v9ses->aname);
+		if (IS_ERR(fid))
+			return fid;
 
-	if (ds == dentry)
+		v9fs_fid_add(dentry->d_sb->s_root, fid);
+	}
+	/* If we are root ourself just return that */
+	if (dentry->d_sb->s_root == dentry)
 		return fid;
-
-	wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL);
-	if (!wnames)
-		return ERR_PTR(-ENOMEM);
-
-	for (d = dentry, i = (n-1); i >= 0; i--, d = d->d_parent)
-		wnames[i] = (char *) d->d_name.name;
-
+	/*
+	 * Do a multipath walk with attached root.
+	 * When walking parent we need to make sure we
+	 * don't have a parallel rename happening
+	 */
+	down_read(&v9ses->rename_sem);
+	n  = build_path_from_dentry(v9ses, dentry, &wnames);
+	if (n < 0) {
+		fid = ERR_PTR(n);
+		goto err_out;
+	}
 	clone = 1;
 	i = 0;
 	while (i < n) {
 		l = min(n - i, P9_MAXWELEM);
+		/*
+		 * We need to hold rename lock when doing a multipath
+		 * walk to ensure none of the patch component change
+		 */
 		fid = p9_client_walk(fid, l, &wnames[i], clone);
 		if (IS_ERR(fid)) {
 			if (old_fid) {
@@ -193,15 +234,17 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 				p9_client_clunk(old_fid);
 			}
 			kfree(wnames);
-			return fid;
+			goto err_out;
 		}
 		old_fid = fid;
 		i += l;
 		clone = 0;
 	}
-
 	kfree(wnames);
+fid_out:
 	v9fs_fid_add(dentry, fid);
+err_out:
+	up_read(&v9ses->rename_sem);
 	return fid;
 }
 

fs/9p/v9fs.c

@@ -237,6 +237,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		__putname(v9ses->uname);
 		return ERR_PTR(-ENOMEM);
 	}
+	init_rwsem(&v9ses->rename_sem);
 
 	rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
 	if (rc) {
@@ -278,7 +279,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
-	if (!v9fs_proto_dotu(v9ses) &&
+	if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 
 		v9ses->flags &= ~V9FS_ACCESS_MASK;

fs/9p/v9fs.h

@@ -104,6 +104,7 @@ struct v9fs_session_info {
 	struct p9_client *clnt;	/* 9p client */
 	struct list_head slist; /* list of sessions registered with v9fs */
 	struct backing_dev_info bdi;
+	struct rw_semaphore rename_sem;
 };
 
 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,

fs/9p/v9fs_vfs.h

@@ -55,6 +55,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode);
 void v9fs_clear_inode(struct inode *inode);
 ino_t v9fs_qid2ino(struct p9_qid *qid);
 void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
+void v9fs_stat2inode_dotl(struct p9_stat_dotl *, struct inode *);
 int v9fs_dir_release(struct inode *inode, struct file *filp);
 int v9fs_file_open(struct inode *inode, struct file *file);
 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);

fs/9p/vfs_dir.c

@@ -87,29 +87,19 @@ static void p9stat_init(struct p9_wstat *stbuf)
 }
 
 /**
- * v9fs_dir_readdir - read a directory
+ * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
  * @filp: opened file structure
- * @dirent: directory structure ???
- * @filldir: function to populate directory structure ???
+ * @buflen: Length in bytes of buffer to allocate
  *
  */
 
-static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
 {
-	int over;
-	struct p9_wstat st;
-	int err = 0;
-	struct p9_fid *fid;
-	int buflen;
-	int reclen = 0;
 	struct p9_rdir *rdir;
+	struct p9_fid *fid;
+	int err = 0;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
 	fid = filp->private_data;
-
-	buflen = fid->clnt->msize - P9_IOHDRSZ;
-
-	/* allocate rdir on demand */
 	if (!fid->rdir) {
 		rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
 
@@ -128,6 +118,36 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		spin_unlock(&filp->f_dentry->d_lock);
 		kfree(rdir);
 	}
+exit:
+	return err;
+}
+
+/**
+ * v9fs_dir_readdir - read a directory
+ * @filp: opened file structure
+ * @dirent: directory structure ???
+ * @filldir: function to populate directory structure ???
+ *
+ */
+
+static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	int over;
+	struct p9_wstat st;
+	int err = 0;
+	struct p9_fid *fid;
+	int buflen;
+	int reclen = 0;
+	struct p9_rdir *rdir;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+	fid = filp->private_data;
+
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+
+	err = v9fs_alloc_rdir_buf(filp, buflen);
+	if (err)
+		goto exit;
 	rdir = (struct p9_rdir *) fid->rdir;
 
 	err = mutex_lock_interruptible(&rdir->mutex);
@@ -176,6 +196,88 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 	return err;
 }
 
+/**
+ * v9fs_dir_readdir_dotl - read a directory
+ * @filp: opened file structure
+ * @dirent: buffer to fill dirent structures
+ * @filldir: function to populate dirent structures
+ *
+ */
+static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
+						filldir_t filldir)
+{
+	int over;
+	int err = 0;
+	struct p9_fid *fid;
+	int buflen;
+	struct p9_rdir *rdir;
+	struct p9_dirent curdirent;
+	u64 oldoffset = 0;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+	fid = filp->private_data;
+
+	buflen = fid->clnt->msize - P9_READDIRHDRSZ;
+
+	err = v9fs_alloc_rdir_buf(filp, buflen);
+	if (err)
+		goto exit;
+	rdir = (struct p9_rdir *) fid->rdir;
+
+	err = mutex_lock_interruptible(&rdir->mutex);
+	if (err)
+		return err;
+
+	while (err == 0) {
+		if (rdir->tail == rdir->head) {
+			err = p9_client_readdir(fid, rdir->buf, buflen,
+								filp->f_pos);
+			if (err <= 0)
+				goto unlock_and_exit;
+
+			rdir->head = 0;
+			rdir->tail = err;
+		}
+
+		while (rdir->head < rdir->tail) {
+
+			err = p9dirent_read(rdir->buf + rdir->head,
+						buflen - rdir->head, &curdirent,
+						fid->clnt->proto_version);
+			if (err < 0) {
+				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
+				err = -EIO;
+				goto unlock_and_exit;
+			}
+
+			/* d_off in dirent structure tracks the offset into
+			 * the next dirent in the dir. However, filldir()
+			 * expects offset into the current dirent. Hence
+			 * while calling filldir send the offset from the
+			 * previous dirent structure.
+			 */
+			over = filldir(dirent, curdirent.d_name,
+					strlen(curdirent.d_name),
+					oldoffset, v9fs_qid2ino(&curdirent.qid),
+					curdirent.d_type);
+			oldoffset = curdirent.d_off;
+
+			if (over) {
+				err = 0;
+				goto unlock_and_exit;
+			}
+
+			filp->f_pos = curdirent.d_off;
+			rdir->head += err;
+		}
+	}
+
+unlock_and_exit:
+	mutex_unlock(&rdir->mutex);
+exit:
+	return err;
+}
+
 
 /**
  * v9fs_dir_release - close a directory
@@ -207,7 +309,7 @@ const struct file_operations v9fs_dir_operations = {
 const struct file_operations v9fs_dir_operations_dotl = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
-	.readdir = v9fs_dir_readdir,
+	.readdir = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 };