1 files changed, 363 insertions, 0 deletions
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
new file mode 100644
index 000000000..9a21269b7
--- /dev/null
+++ b/fs/9p/vfs_super.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/9p/vfs_super.c
+ *
+ * This file contians superblock ops for 9P2000. It is intended that
+ * you mount this file system on directories.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/pagemap.h>
+#include <linux/mount.h>
+#include <linux/idr.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/magic.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+#include "xattr.h"
+#include "acl.h"
+
+static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
+
+/**
+ * v9fs_set_super - set the superblock
+ * @s: super block
+ * @data: file system specific data
+ *
+ */
+
+static int v9fs_set_super(struct super_block *s, void *data)
+{
+	s->s_fs_info = data;
+	return set_anon_super(s, data);
+}
+
+/**
+ * v9fs_fill_super - populate superblock with info
+ * @sb: superblock
+ * @v9ses: session information
+ * @flags: flags propagated from v9fs_mount()
+ *
+ */
+
+static int
+v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
+		int flags)
+{
+	int ret;
+
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
+	sb->s_blocksize = 1 << sb->s_blocksize_bits;
+	sb->s_magic = V9FS_MAGIC;
+	if (v9fs_proto_dotl(v9ses)) {
+		sb->s_op = &v9fs_super_ops_dotl;
+		sb->s_xattr = v9fs_xattr_handlers;
+	} else {
+		sb->s_op = &v9fs_super_ops;
+		sb->s_time_max = U32_MAX;
+	}
+
+	sb->s_time_min = 0;
+
+	ret = super_setup_bdi(sb);
+	if (ret)
+		return ret;
+
+	if (!v9ses->cache) {
+		sb->s_bdi->ra_pages = 0;
+		sb->s_bdi->io_pages = 0;
+	}
+
+	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
+	if (!v9ses->cache)
+		sb->s_flags |= SB_SYNCHRONOUS;
+
+#ifdef CONFIG_9P_FS_POSIX_ACL
+	if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
+		sb->s_flags |= SB_POSIXACL;
+#endif
+
+	return 0;
+}
+
+/**
+ * v9fs_mount - mount a superblock
+ * @fs_type: file system type
+ * @flags: mount flags
+ * @dev_name: device name that was mounted
+ * @data: mount options
+ *
+ */
+
+static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
+		       const char *dev_name, void *data)
+{
+	struct super_block *sb = NULL;
+	struct inode *inode = NULL;
+	struct dentry *root = NULL;
+	struct v9fs_session_info *v9ses = NULL;
+	umode_t mode = S_IRWXUGO | S_ISVTX;
+	struct p9_fid *fid;
+	int retval = 0;
+
+	p9_debug(P9_DEBUG_VFS, "\n");
+
+	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
+	if (!v9ses)
+		return ERR_PTR(-ENOMEM);
+
+	fid = v9fs_session_init(v9ses, dev_name, data);
+	if (IS_ERR(fid)) {
+		retval = PTR_ERR(fid);
+		goto free_session;
+	}
+
+	sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
+	if (IS_ERR(sb)) {
+		retval = PTR_ERR(sb);
+		goto clunk_fid;
+	}
+	retval = v9fs_fill_super(sb, v9ses, flags);
+	if (retval)
+		goto release_sb;
+
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		sb->s_d_op = &v9fs_cached_dentry_operations;
+	else
+		sb->s_d_op = &v9fs_dentry_operations;
+
+	inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
+	if (IS_ERR(inode)) {
+		retval = PTR_ERR(inode);
+		goto release_sb;
+	}
+
+	root = d_make_root(inode);
+	if (!root) {
+		retval = -ENOMEM;
+		goto release_sb;
+	}
+	sb->s_root = root;
+	if (v9fs_proto_dotl(v9ses)) {
+		struct p9_stat_dotl *st = NULL;
+		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
+		if (IS_ERR(st)) {
+			retval = PTR_ERR(st);
+			goto release_sb;
+		}
+		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
+		v9fs_stat2inode_dotl(st, d_inode(root), 0);
+		kfree(st);
+	} else {
+		struct p9_wstat *st = NULL;
+		st = p9_client_stat(fid);
+		if (IS_ERR(st)) {
+			retval = PTR_ERR(st);
+			goto release_sb;
+		}
+
+		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
+		v9fs_stat2inode(st, d_inode(root), sb, 0);
+
+		p9stat_free(st);
+		kfree(st);
+	}
+	retval = v9fs_get_acl(inode, fid);
+	if (retval)
+		goto release_sb;
+	v9fs_fid_add(root, fid);
+
+	p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
+	return dget(sb->s_root);
+
+clunk_fid:
+	p9_client_clunk(fid);
+	v9fs_session_close(v9ses);
+free_session:
+	kfree(v9ses);
+	return ERR_PTR(retval);
+
+release_sb:
+	/*
+	 * we will do the session_close and root dentry release
+	 * in the below call. But we need to clunk fid, because we haven't
+	 * attached the fid to dentry so it won't get clunked
+	 * automatically.
+	 */
+	p9_client_clunk(fid);
+	deactivate_locked_super(sb);
+	return ERR_PTR(retval);
+}
+
+/**
+ * v9fs_kill_super - Kill Superblock
+ * @s: superblock
+ *
+ */
+
+static void v9fs_kill_super(struct super_block *s)
+{
+	struct v9fs_session_info *v9ses = s->s_fs_info;
+
+	p9_debug(P9_DEBUG_VFS, " %p\n", s);
+
+	kill_anon_super(s);
+
+	v9fs_session_cancel(v9ses);
+	v9fs_session_close(v9ses);
+	kfree(v9ses);
+	s->s_fs_info = NULL;
+	p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
+}
+
+static void
+v9fs_umount_begin(struct super_block *sb)
+{
+	struct v9fs_session_info *v9ses;
+
+	v9ses = sb->s_fs_info;
+	v9fs_session_begin_cancel(v9ses);
+}
+
+static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid;
+	struct p9_rstatfs rs;
+	int res;
+
+	fid = v9fs_fid_lookup(dentry);
+	if (IS_ERR(fid)) {
+		res = PTR_ERR(fid);
+		goto done;
+	}
+
+	v9ses = v9fs_dentry2v9ses(dentry);
+	if (v9fs_proto_dotl(v9ses)) {
+		res = p9_client_statfs(fid, &rs);
+		if (res == 0) {
+			buf->f_type = rs.type;
+			buf->f_bsize = rs.bsize;
+			buf->f_blocks = rs.blocks;
+			buf->f_bfree = rs.bfree;
+			buf->f_bavail = rs.bavail;
+			buf->f_files = rs.files;
+			buf->f_ffree = rs.ffree;
+			buf->f_fsid = u64_to_fsid(rs.fsid);
+			buf->f_namelen = rs.namelen;
+		}
+		if (res != -ENOSYS)
+			goto done;
+	}
+	res = simple_statfs(dentry, buf);
+done:
+	return res;
+}
+
+static int v9fs_drop_inode(struct inode *inode)
+{
+	struct v9fs_session_info *v9ses;
+	v9ses = v9fs_inode2v9ses(inode);
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
+		return generic_drop_inode(inode);
+	/*
+	 * in case of non cached mode always drop the
+	 * the inode because we want the inode attribute
+	 * to always match that on the server.
+	 */
+	return 1;
+}
+
+static int v9fs_write_inode(struct inode *inode,
+			    struct writeback_control *wbc)
+{
+	int ret;
+	struct p9_wstat wstat;
+	struct v9fs_inode *v9inode;
+	/*
+	 * send an fsync request to server irrespective of
+	 * wbc->sync_mode.
+	 */
+	p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
+	v9inode = V9FS_I(inode);
+	if (!v9inode->writeback_fid)
+		return 0;
+	v9fs_blank_wstat(&wstat);
+
+	ret = p9_client_wstat(v9inode->writeback_fid, &wstat);
+	if (ret < 0) {
+		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+		return ret;
+	}
+	return 0;
+}
+
+static int v9fs_write_inode_dotl(struct inode *inode,
+				 struct writeback_control *wbc)
+{
+	int ret;
+	struct v9fs_inode *v9inode;
+	/*
+	 * send an fsync request to server irrespective of
+	 * wbc->sync_mode.
+	 */
+	v9inode = V9FS_I(inode);
+	p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n",
+		 __func__, inode, v9inode->writeback_fid);
+	if (!v9inode->writeback_fid)
+		return 0;
+
+	ret = p9_client_fsync(v9inode->writeback_fid, 0);
+	if (ret < 0) {
+		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+		return ret;
+	}
+	return 0;
+}
+
+static const struct super_operations v9fs_super_ops = {
+	.alloc_inode = v9fs_alloc_inode,
+	.free_inode = v9fs_free_inode,
+	.statfs = simple_statfs,
+	.evict_inode = v9fs_evict_inode,
+	.show_options = v9fs_show_options,
+	.umount_begin = v9fs_umount_begin,
+	.write_inode = v9fs_write_inode,
+};
+
+static const struct super_operations v9fs_super_ops_dotl = {
+	.alloc_inode = v9fs_alloc_inode,
+	.free_inode = v9fs_free_inode,
+	.statfs = v9fs_statfs,
+	.drop_inode = v9fs_drop_inode,
+	.evict_inode = v9fs_evict_inode,
+	.show_options = v9fs_show_options,
+	.umount_begin = v9fs_umount_begin,
+	.write_inode = v9fs_write_inode_dotl,
+};
+
+struct file_system_type v9fs_fs_type = {
+	.name = "9p",
+	.mount = v9fs_mount,
+	.kill_sb = v9fs_kill_super,
+	.owner = THIS_MODULE,
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
+};
+MODULE_ALIAS_FS("9p");