1 files changed, 241 insertions, 213 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 879ed885173..7fa4f7a7653 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -23,6 +23,8 @@
  *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
@@ -59,15 +61,13 @@ static const struct inode_operations v9fs_symlink_inode_operations;
  *
  */
 
-static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
+static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
 {
 	int res;
 	res = mode & 0777;
 	if (S_ISDIR(mode))
 		res |= P9_DMDIR;
 	if (v9fs_proto_dotu(v9ses)) {
-		if (S_ISLNK(mode))
-			res |= P9_DMSYMLINK;
 		if (v9ses->nodev == 0) {
 			if (S_ISSOCK(mode))
 				res |= P9_DMSOCKET;
@@ -85,10 +85,33 @@ static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
 			res |= P9_DMSETGID;
 		if ((mode & S_ISVTX) == S_ISVTX)
 			res |= P9_DMSETVTX;
-		if ((mode & P9_DMLINK))
-			res |= P9_DMLINK;
 	}
+	return res;
+}
+
+/**
+ * p9mode2perm- convert plan9 mode bits to unix permission bits
+ * @v9ses: v9fs session information
+ * @stat: p9_wstat from which mode need to be derived
+ *
+ */
+static int p9mode2perm(struct v9fs_session_info *v9ses,
+		       struct p9_wstat *stat)
+{
+	int res;
+	int mode = stat->mode;
+
+	res = mode & S_IALLUGO;
+	if (v9fs_proto_dotu(v9ses)) {
+		if ((mode & P9_DMSETUID) == P9_DMSETUID)
+			res |= S_ISUID;
+
+		if ((mode & P9_DMSETGID) == P9_DMSETGID)
+			res |= S_ISGID;
 
+		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
+			res |= S_ISVTX;
+	}
 	return res;
 }
 
@@ -99,14 +122,14 @@ static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  * @rdev: major number, minor number in case of device files.
  *
  */
-static int p9mode2unixmode(struct v9fs_session_info *v9ses,
-			   struct p9_wstat *stat, dev_t *rdev)
+static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
+			       struct p9_wstat *stat, dev_t *rdev)
 {
 	int res;
-	int mode = stat->mode;
+	u32 mode = stat->mode;
 
-	res = mode & S_IALLUGO;
 	*rdev = 0;
+	res = p9mode2perm(v9ses, stat);
 
 	if ((mode & P9_DMDIR) == P9_DMDIR)
 		res |= S_IFDIR;
@@ -123,8 +146,8 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses,
 		char type = 0, ext[32];
 		int major = -1, minor = -1;
 
-		strncpy(ext, stat->extension, sizeof(ext));
-		sscanf(ext, "%c %u %u", &type, &major, &minor);
+		strlcpy(ext, stat->extension, sizeof(ext));
+		sscanf(ext, "%c %i %i", &type, &major, &minor);
 		switch (type) {
 		case 'c':
 			res |= S_IFCHR;
@@ -133,24 +156,13 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses,
 			res |= S_IFBLK;
 			break;
 		default:
-			P9_DPRINTK(P9_DEBUG_ERROR,
-				"Unknown special type %c %s\n", type,
-				stat->extension);
+			p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
+				 type, stat->extension);
 		};
 		*rdev = MKDEV(major, minor);
 	} else
 		res |= S_IFREG;
 
-	if (v9fs_proto_dotu(v9ses)) {
-		if ((mode & P9_DMSETUID) == P9_DMSETUID)
-			res |= S_ISUID;
-
-		if ((mode & P9_DMSETGID) == P9_DMSETGID)
-			res |= S_ISGID;
-
-		if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
-			res |= S_ISVTX;
-	}
 	return res;
 }
 
@@ -180,9 +192,6 @@ int v9fs_uflags2omode(int uflags, int extended)
 		break;
 	}
 
-	if (uflags & O_TRUNC)
-		ret |= P9_OTRUNC;
-
 	if (extended) {
 		if (uflags & O_EXCL)
 			ret |= P9_OEXCL;
@@ -216,9 +225,9 @@ v9fs_blank_wstat(struct p9_wstat *wstat)
 	wstat->uid = NULL;
 	wstat->gid = NULL;
 	wstat->muid = NULL;
-	wstat->n_uid = ~0;
-	wstat->n_gid = ~0;
-	wstat->n_muid = ~0;
+	wstat->n_uid = INVALID_UID;
+	wstat->n_gid = INVALID_GID;
+	wstat->n_muid = INVALID_UID;
 	wstat->extension = NULL;
 }
 
@@ -251,7 +260,6 @@ struct inode *v9fs_alloc_inode(struct super_block *sb)
 static void v9fs_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
-	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 }
 
@@ -261,7 +269,7 @@ void v9fs_destroy_inode(struct inode *inode)
 }
 
 int v9fs_init_inode(struct v9fs_session_info *v9ses,
-		    struct inode *inode, int mode, dev_t rdev)
+		    struct inode *inode, umode_t mode, dev_t rdev)
 {
 	int err = 0;
 
@@ -281,8 +289,8 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 		} else if (v9fs_proto_dotu(v9ses)) {
 			inode->i_op = &v9fs_file_inode_operations;
 		} else {
-			P9_DPRINTK(P9_DEBUG_ERROR,
-				   "special files without extended mode\n");
+			p9_debug(P9_DEBUG_ERROR,
+				 "special files without extended mode\n");
 			err = -EINVAL;
 			goto error;
 		}
@@ -291,15 +299,22 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 	case S_IFREG:
 		if (v9fs_proto_dotl(v9ses)) {
 			inode->i_op = &v9fs_file_inode_operations_dotl;
-			if (v9ses->cache)
+			if (v9ses->cache == CACHE_LOOSE ||
+			    v9ses->cache == CACHE_FSCACHE)
 				inode->i_fop =
 					&v9fs_cached_file_operations_dotl;
+			else if (v9ses->cache == CACHE_MMAP)
+				inode->i_fop = &v9fs_mmap_file_operations_dotl;
 			else
 				inode->i_fop = &v9fs_file_operations_dotl;
 		} else {
 			inode->i_op = &v9fs_file_inode_operations;
-			if (v9ses->cache)
-				inode->i_fop = &v9fs_cached_file_operations;
+			if (v9ses->cache == CACHE_LOOSE ||
+			    v9ses->cache == CACHE_FSCACHE)
+				inode->i_fop =
+					&v9fs_cached_file_operations;
+			else if (v9ses->cache == CACHE_MMAP)
+				inode->i_fop = &v9fs_mmap_file_operations;
 			else
 				inode->i_fop = &v9fs_file_operations;
 		}
@@ -307,8 +322,8 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 		break;
 	case S_IFLNK:
 		if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
-			P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
-						"legacy protocol.\n");
+			p9_debug(P9_DEBUG_ERROR,
+				 "extended modes used with legacy protocol\n");
 			err = -EINVAL;
 			goto error;
 		}
@@ -335,8 +350,8 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 
 		break;
 	default:
-		P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
-			   mode, mode & S_IFMT);
+		p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
+			 mode, mode & S_IFMT);
 		err = -EINVAL;
 		goto error;
 	}
@@ -352,17 +367,18 @@ error:
  *
  */
 
-struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t rdev)
+struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 {
 	int err;
 	struct inode *inode;
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
+	p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 
 	inode = new_inode(sb);
 	if (!inode) {
-		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
+		pr_warn("%s (%d): Problem allocating inode\n",
+			__func__, task_pid_nr(current));
 		return ERR_PTR(-ENOMEM);
 	}
 	err = v9fs_init_inode(v9ses, inode, mode, rdev);
@@ -435,13 +451,11 @@ void v9fs_evict_inode(struct inode *inode)
 {
 	struct v9fs_inode *v9inode = V9FS_I(inode);
 
-	truncate_inode_pages(inode->i_mapping, 0);
-	end_writeback(inode);
+	truncate_inode_pages_final(inode->i_mapping);
+	clear_inode(inode);
 	filemap_fdatawrite(inode->i_mapping);
 
-#ifdef CONFIG_9P_FSCACHE
 	v9fs_cache_inode_put_cookie(inode);
-#endif
 	/* clunk the fid stashed in writeback_fid */
 	if (v9inode->writeback_fid) {
 		p9_client_clunk(v9inode->writeback_fid);
@@ -492,7 +506,8 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
 				   int new)
 {
 	dev_t rdev;
-	int retval, umode;
+	int retval;
+	umode_t umode;
 	unsigned long i_ino;
 	struct inode *inode;
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
@@ -521,9 +536,7 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
 		goto error;
 
 	v9fs_stat2inode(st, inode, sb);
-#ifdef CONFIG_9P_FSCACHE
 	v9fs_cache_inode_get_cookie(inode);
-#endif
 	unlock_new_inode(inode);
 	return inode;
 error:
@@ -567,7 +580,7 @@ static int v9fs_at_to_dotl_flags(int flags)
  * v9fs_remove - helper function to remove files and directories
  * @dir: directory inode that is being deleted
  * @dentry:  dentry that is being deleted
- * @rmdir: removing a directory
+ * @flags: removing a directory
  *
  */
 
@@ -578,15 +591,15 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 	struct p9_fid *v9fid, *dfid;
 	struct v9fs_session_info *v9ses;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
-		   dir, dentry, flags);
+	p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
+		 dir, dentry, flags);
 
 	v9ses = v9fs_inode2v9ses(dir);
 	inode = dentry->d_inode;
 	dfid = v9fs_fid_lookup(dentry->d_parent);
 	if (IS_ERR(dfid)) {
 		retval = PTR_ERR(dfid);
-		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
+		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 		return retval;
 	}
 	if (v9fs_proto_dotl(v9ses))
@@ -635,7 +648,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	struct p9_fid *dfid, *ofid, *fid;
 	struct inode *inode;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 
 	err = 0;
 	ofid = NULL;
@@ -644,7 +657,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	dfid = v9fs_fid_lookup(dentry->d_parent);
 	if (IS_ERR(dfid)) {
 		err = PTR_ERR(dfid);
-		P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
+		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 		return ERR_PTR(err);
 	}
 
@@ -652,36 +665,39 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	ofid = p9_client_walk(dfid, 0, NULL, 1);
 	if (IS_ERR(ofid)) {
 		err = PTR_ERR(ofid);
-		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
+		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 		return ERR_PTR(err);
 	}
 
 	err = p9_client_fcreate(ofid, name, perm, mode, extension);
 	if (err < 0) {
-		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
-		goto error;
-	}
-
-	/* now walk from the parent so we can get unopened fid */
-	fid = p9_client_walk(dfid, 1, &name, 1);
-	if (IS_ERR(fid)) {
-		err = PTR_ERR(fid);
-		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
-		fid = NULL;
+		p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 		goto error;
 	}
 
-	/* instantiate inode and assign the unopened fid to the dentry */
-	inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
-	if (IS_ERR(inode)) {
-		err = PTR_ERR(inode);
-		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
-		goto error;
+	if (!(perm & P9_DMLINK)) {
+		/* now walk from the parent so we can get unopened fid */
+		fid = p9_client_walk(dfid, 1, &name, 1);
+		if (IS_ERR(fid)) {
+			err = PTR_ERR(fid);
+			p9_debug(P9_DEBUG_VFS,
+				   "p9_client_walk failed %d\n", err);
+			fid = NULL;
+			goto error;
+		}
+		/*
+		 * instantiate inode and assign the unopened fid to the dentry
+		 */
+		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
+		if (IS_ERR(inode)) {
+			err = PTR_ERR(inode);
+			p9_debug(P9_DEBUG_VFS,
+				   "inode creation failed %d\n", err);
+			goto error;
+		}
+		v9fs_fid_add(dentry, fid);
+		d_instantiate(dentry, inode);
 	}
-	err = v9fs_fid_add(dentry, fid);
-	if (err < 0)
-		goto error;
-	d_instantiate(dentry, inode);
 	return ofid;
 error:
 	if (ofid)
@@ -694,88 +710,34 @@ error:
 }
 
 /**
- * v9fs_vfs_create - VFS hook to create files
+ * v9fs_vfs_create - VFS hook to create a regular file
+ *
+ * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
+ * for mknod(2).
+ *
  * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @mode: create permissions
- * @nd: path information
  *
  */
 
 static int
-v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
-		struct nameidata *nd)
+v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+		bool excl)
 {
-	int err;
-	u32 perm;
-	int flags;
-	struct file *filp;
-	struct v9fs_inode *v9inode;
-	struct v9fs_session_info *v9ses;
-	struct p9_fid *fid, *inode_fid;
-
-	err = 0;
-	fid = NULL;
-	v9ses = v9fs_inode2v9ses(dir);
-	perm = unixmode2p9mode(v9ses, mode);
-	if (nd)
-		flags = nd->intent.open.flags;
-	else
-		flags = O_RDWR;
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
+	u32 perm = unixmode2p9mode(v9ses, mode);
+	struct p9_fid *fid;
 
-	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
-				v9fs_uflags2omode(flags,
-						v9fs_proto_dotu(v9ses)));
-	if (IS_ERR(fid)) {
-		err = PTR_ERR(fid);
-		fid = NULL;
-		goto error;
-	}
+	/* P9_OEXCL? */
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
+	if (IS_ERR(fid))
+		return PTR_ERR(fid);
 
 	v9fs_invalidate_inode_attr(dir);
-	/* if we are opening a file, assign the open fid to the file */
-	if (nd) {
-		v9inode = V9FS_I(dentry->d_inode);
-		mutex_lock(&v9inode->v_mutex);
-		if (v9ses->cache && !v9inode->writeback_fid &&
-		    ((flags & O_ACCMODE) != O_RDONLY)) {
-			/*
-			 * clone a fid and add it to writeback_fid
-			 * we do it during open time instead of
-			 * page dirty time via write_begin/page_mkwrite
-			 * because we want write after unlink usecase
-			 * to work.
-			 */
-			inode_fid = v9fs_writeback_fid(dentry);
-			if (IS_ERR(inode_fid)) {
-				err = PTR_ERR(inode_fid);
-				mutex_unlock(&v9inode->v_mutex);
-				goto error;
-			}
-			v9inode->writeback_fid = (void *) inode_fid;
-		}
-		mutex_unlock(&v9inode->v_mutex);
-		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
-		if (IS_ERR(filp)) {
-			err = PTR_ERR(filp);
-			goto error;
-		}
-
-		filp->private_data = fid;
-#ifdef CONFIG_9P_FSCACHE
-		if (v9ses->cache)
-			v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
-#endif
-	} else
-		p9_client_clunk(fid);
+	p9_client_clunk(fid);
 
 	return 0;
-
-error:
-	if (fid)
-		p9_client_clunk(fid);
-
-	return err;
 }
 
 /**
@@ -786,14 +748,14 @@ error:
  *
  */
 
-static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	int err;
 	u32 perm;
 	struct p9_fid *fid;
 	struct v9fs_session_info *v9ses;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 	err = 0;
 	v9ses = v9fs_inode2v9ses(dir);
 	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
@@ -816,28 +778,25 @@ static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
  * @dir:  inode that is being walked from
  * @dentry: dentry that is being walked to?
- * @nameidata: path data
+ * @flags: lookup flags (unused)
  *
  */
 
 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
-				      struct nameidata *nameidata)
+				      unsigned int flags)
 {
 	struct dentry *res;
-	struct super_block *sb;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *dfid, *fid;
 	struct inode *inode;
 	char *name;
-	int result = 0;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
-		dir, dentry->d_name.name, dentry, nameidata);
+	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n",
+		 dir, dentry->d_name.name, dentry, flags);
 
 	if (dentry->d_name.len > NAME_MAX)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	sb = dir->i_sb;
 	v9ses = v9fs_inode2v9ses(dir);
 	/* We can walk d_parent because we hold the dir->i_mutex */
 	dfid = v9fs_fid_lookup(dentry->d_parent);
@@ -847,32 +806,25 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	name = (char *) dentry->d_name.name;
 	fid = p9_client_walk(dfid, 1, &name, 1);
 	if (IS_ERR(fid)) {
-		result = PTR_ERR(fid);
-		if (result == -ENOENT) {
-			inode = NULL;
-			goto inst_out;
+		if (fid == ERR_PTR(-ENOENT)) {
+			d_add(dentry, NULL);
+			return NULL;
 		}
-
-		return ERR_PTR(result);
+		return ERR_CAST(fid);
 	}
 	/*
 	 * Make sure we don't use a wrong inode due to parallel
 	 * unlink. For cached mode create calls request for new
 	 * inode. But with cache disabled, lookup should do this.
 	 */
-	if (v9ses->cache)
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 	else
 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 	if (IS_ERR(inode)) {
-		result = PTR_ERR(inode);
-		inode = NULL;
-		goto error;
+		p9_client_clunk(fid);
+		return ERR_CAST(inode);
 	}
-	result = v9fs_fid_add(dentry, fid);
-	if (result < 0)
-		goto error_iput;
-inst_out:
 	/*
 	 * If we had a rename on the server and a parallel lookup
 	 * for the new name, then make sure we instantiate with
@@ -881,15 +833,92 @@ inst_out:
 	 * k/b.
 	 */
 	res = d_materialise_unique(dentry, inode);
-	if (!IS_ERR(res))
-		return res;
-	result = PTR_ERR(res);
-error_iput:
-	iput(inode);
-error:
-	p9_client_clunk(fid);
+	if (!res)
+		v9fs_fid_add(dentry, fid);
+	else if (!IS_ERR(res))
+		v9fs_fid_add(res, fid);
+	else
+		p9_client_clunk(fid);
+	return res;
+}
 
-	return ERR_PTR(result);
+static int
+v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
+		     struct file *file, unsigned flags, umode_t mode,
+		     int *opened)
+{
+	int err;
+	u32 perm;
+	struct v9fs_inode *v9inode;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid, *inode_fid;
+	struct dentry *res = NULL;
+
+	if (d_unhashed(dentry)) {
+		res = v9fs_vfs_lookup(dir, dentry, 0);
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT) || dentry->d_inode)
+		return finish_no_open(file, res);
+
+	err = 0;
+
+	v9ses = v9fs_inode2v9ses(dir);
+	perm = unixmode2p9mode(v9ses, mode);
+	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
+				v9fs_uflags2omode(flags,
+						v9fs_proto_dotu(v9ses)));
+	if (IS_ERR(fid)) {
+		err = PTR_ERR(fid);
+		fid = NULL;
+		goto error;
+	}
+
+	v9fs_invalidate_inode_attr(dir);
+	v9inode = V9FS_I(dentry->d_inode);
+	mutex_lock(&v9inode->v_mutex);
+	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
+	    !v9inode->writeback_fid &&
+	    ((flags & O_ACCMODE) != O_RDONLY)) {
+		/*
+		 * clone a fid and add it to writeback_fid
+		 * we do it during open time instead of
+		 * page dirty time via write_begin/page_mkwrite
+		 * because we want write after unlink usecase
+		 * to work.
+		 */
+		inode_fid = v9fs_writeback_fid(dentry);
+		if (IS_ERR(inode_fid)) {
+			err = PTR_ERR(inode_fid);
+			mutex_unlock(&v9inode->v_mutex);
+			goto error;
+		}
+		v9inode->writeback_fid = (void *) inode_fid;
+	}
+	mutex_unlock(&v9inode->v_mutex);
+	err = finish_open(file, dentry, generic_file_open, opened);
+	if (err)
+		goto error;
+
+	file->private_data = fid;
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		v9fs_cache_inode_set_cookie(dentry->d_inode, file);
+
+	*opened |= FILE_CREATED;
+out:
+	dput(res);
+	return err;
+
+error:
+	if (fid)
+		p9_client_clunk(fid);
+	goto out;
 }
 
 /**
@@ -938,7 +967,7 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct p9_fid *newdirfid;
 	struct p9_wstat wstat;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+	p9_debug(P9_DEBUG_VFS, "\n");
 	retval = 0;
 	old_inode = old_dentry->d_inode;
 	new_inode = new_dentry->d_inode;
@@ -974,8 +1003,7 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		 * 9P .u can only handle file rename in the same directory
 		 */
 
-		P9_DPRINTK(P9_DEBUG_ERROR,
-				"old dir and new dir are different\n");
+		p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 		retval = -EXDEV;
 		goto clunk_newdir;
 	}
@@ -1026,13 +1054,11 @@ static int
 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 		 struct kstat *stat)
 {
-	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	struct p9_wstat *st;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
-	err = -EPERM;
+	p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 	v9ses = v9fs_dentry2v9ses(dentry);
 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
 		generic_fillattr(dentry->d_inode, stat);
@@ -1068,7 +1094,7 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 	struct p9_fid *fid;
 	struct p9_wstat wstat;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+	p9_debug(P9_DEBUG_VFS, "\n");
 	retval = inode_change_ok(dentry->d_inode, iattr);
 	if (retval)
 		return retval;
@@ -1131,7 +1157,7 @@ void
 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	struct super_block *sb)
 {
-	mode_t mode;
+	umode_t mode;
 	char ext[32];
 	char tag_name[14];
 	unsigned int i_nlink;
@@ -1160,14 +1186,14 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 			 * this even with .u extension. So check
 			 * for non NULL stat->extension
 			 */
-			strncpy(ext, stat->extension, sizeof(ext));
+			strlcpy(ext, stat->extension, sizeof(ext));
 			/* HARDLINKCOUNT %u */
 			sscanf(ext, "%13s %u", tag_name, &i_nlink);
 			if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
 				set_nlink(inode, i_nlink);
 		}
 	}
-	mode = stat->mode & S_IALLUGO;
+	mode = p9mode2perm(v9ses, stat);
 	mode |= inode->i_mode & ~S_IALLUGO;
 	inode->i_mode = mode;
 	i_size_write(inode, stat->length);
@@ -1213,7 +1239,7 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 	struct p9_fid *fid;
 	struct p9_wstat *st;
 
-	P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 	retval = -EPERM;
 	v9ses = v9fs_dentry2v9ses(dentry);
 	fid = v9fs_fid_lookup(dentry);
@@ -1233,12 +1259,12 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 	}
 
 	/* copy extension buffer into buffer */
-	strncpy(buffer, st->extension, buflen);
+	retval = min(strlen(st->extension)+1, (size_t)buflen);
+	memcpy(buffer, st->extension, retval);
 
-	P9_DPRINTK(P9_DEBUG_VFS,
-		"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
+	p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n",
+		 dentry->d_name.name, st->extension, buflen, buffer);
 
-	retval = strnlen(buffer, buflen);
 done:
 	p9stat_free(st);
 	kfree(st);
@@ -1257,7 +1283,7 @@ static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 	int len = 0;
 	char *link = __getname();
 
-	P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
 
 	if (!link)
 		link = ERR_PTR(-ENOMEM);
@@ -1288,8 +1314,8 @@ v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
 {
 	char *s = nd_get_link(nd);
 
-	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
-		IS_ERR(s) ? "<error>" : s);
+	p9_debug(P9_DEBUG_VFS, " %s %s\n",
+		 dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
 	if (!IS_ERR(s))
 		__putname(s);
 }
@@ -1298,25 +1324,23 @@ v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
  * v9fs_vfs_mkspecial - create a special file
  * @dir: inode to create special file in
  * @dentry: dentry to create
- * @mode: mode to create special file
+ * @perm: 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)
+	u32 perm, const char *extension)
 {
-	u32 perm;
 	struct p9_fid *fid;
 	struct v9fs_session_info *v9ses;
 
 	v9ses = v9fs_inode2v9ses(dir);
 	if (!v9fs_proto_dotu(v9ses)) {
-		P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
+		p9_debug(P9_DEBUG_ERROR, "not extended\n");
 		return -EPERM;
 	}
 
-	perm = unixmode2p9mode(v9ses, mode);
 	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
 								P9_OREAD);
 	if (IS_ERR(fid))
@@ -1340,10 +1364,10 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
 static int
 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
 {
-	P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
-					dentry->d_name.name, symname);
+	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
+		 dir->i_ino, dentry->d_name.name, symname);
 
-	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
+	return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
 }
 
 /**
@@ -1362,9 +1386,8 @@ v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
 	char *name;
 	struct p9_fid *oldfid;
 
-	P9_DPRINTK(P9_DEBUG_VFS,
-		" %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
-		old_dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
+		 dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
 
 	oldfid = v9fs_fid_clone(old_dentry);
 	if (IS_ERR(oldfid))
@@ -1398,14 +1421,16 @@ clunk_fid:
  */
 
 static int
-v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
+v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
 {
+	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 	int retval;
 	char *name;
+	u32 perm;
 
-	P9_DPRINTK(P9_DEBUG_VFS,
-		" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
-		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
+	p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
+		 dir->i_ino, dentry->d_name.name, mode,
+		 MAJOR(rdev), MINOR(rdev));
 
 	if (!new_valid_dev(rdev))
 		return -EINVAL;
@@ -1427,7 +1452,8 @@ v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
 		return -EINVAL;
 	}
 
-	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
+	perm = unixmode2p9mode(v9ses, mode);
+	retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
 	__putname(name);
 
 	return retval;
@@ -1459,7 +1485,7 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
 	 */
 	i_size = inode->i_size;
 	v9fs_stat2inode(st, inode, inode->i_sb);
-	if (v9ses->cache)
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 		inode->i_size = i_size;
 	spin_unlock(&inode->i_lock);
 out:
@@ -1471,6 +1497,7 @@ out:
 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
 	.create = v9fs_vfs_create,
 	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
 	.symlink = v9fs_vfs_symlink,
 	.link = v9fs_vfs_link,
 	.unlink = v9fs_vfs_unlink,
@@ -1485,6 +1512,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = {
 static const struct inode_operations v9fs_dir_inode_operations = {
 	.create = v9fs_vfs_create,
 	.lookup = v9fs_vfs_lookup,
+	.atomic_open = v9fs_vfs_atomic_open,
 	.unlink = v9fs_vfs_unlink,
 	.mkdir = v9fs_vfs_mkdir,
 	.rmdir = v9fs_vfs_rmdir,