1 files changed, 366 insertions, 0 deletions
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
new file mode 100644
index 000000000..94d6b02c2
--- /dev/null
+++ b/fs/9p/vfs_super.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ *  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/pagemap.h>
+#include <linux/mount.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/magic.h>
+#include <linux/fscache.h>
+#include <linux/fs_context.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;
+
+static int v9fs_fill_super(struct super_block *sb)
+{
+	int ret;
+	struct v9fs_session_info *v9ses = v9ses = sb->s_fs_info;
+
+	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;
+		if (!(v9ses->flags & V9FS_NO_XATTR))
+			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;
+	} else {
+		sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT;
+		sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT;
+	}
+
+	sb->s_flags |= SB_ACTIVE;
+
+#ifdef CONFIG_9P_FS_POSIX_ACL
+	if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
+		sb->s_flags |= SB_POSIXACL;
+#endif
+
+	return 0;
+}
+
+/**
+ * v9fs_get_tree - create the mountable root and superblock
+ * @fc: the filesystem context
+ *
+ */
+
+static int v9fs_get_tree(struct fs_context *fc)
+{
+	struct super_block *sb = NULL;
+	struct inode *inode = NULL;
+	struct dentry *root = NULL;
+	struct v9fs_session_info *v9ses = NULL;
+	struct p9_fid *fid;
+	int retval = 0;
+
+	p9_debug(P9_DEBUG_VFS, "\n");
+
+	v9ses = kzalloc_obj(struct v9fs_session_info);
+	if (!v9ses)
+		return -ENOMEM;
+
+	fid = v9fs_session_init(v9ses, fc);
+	if (IS_ERR(fid)) {
+		retval = PTR_ERR(fid);
+		goto free_session;
+	}
+
+	fc->s_fs_info = v9ses;
+	sb = sget_fc(fc, NULL, set_anon_super_fc);
+	if (IS_ERR(sb)) {
+		retval = PTR_ERR(sb);
+		goto clunk_fid;
+	}
+	retval = v9fs_fill_super(sb);
+	if (retval)
+		goto release_sb;
+
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
+		set_default_d_op(sb, &v9fs_cached_dentry_operations);
+	} else {
+		set_default_d_op(sb, &v9fs_dentry_operations);
+		sb->s_d_flags |= DCACHE_DONTCACHE;
+	}
+
+	inode = v9fs_get_new_inode_from_fid(v9ses, fid, sb);
+	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;
+	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");
+	fc->root = dget(sb->s_root);
+	return 0;
+
+clunk_fid:
+	p9_fid_put(fid);
+	v9fs_session_close(v9ses);
+free_session:
+	kfree(v9ses);
+	return 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_fid_put(fid);
+	deactivate_locked_super(sb);
+	return 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:
+	p9_fid_put(fid);
+	return res;
+}
+
+static int v9fs_drop_inode(struct inode *inode)
+{
+	struct v9fs_session_info *v9ses;
+
+	v9ses = v9fs_inode2v9ses(inode);
+	if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
+		return inode_generic_drop(inode);
+	/*
+	 * in case of non cached mode always drop 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)
+{
+	/*
+	 * send an fsync request to server irrespective of
+	 * wbc->sync_mode.
+	 */
+	p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
+	return netfs_unpin_writeback(inode, wbc);
+}
+
+static int v9fs_write_inode_dotl(struct inode *inode,
+				 struct writeback_control *wbc)
+{
+
+	p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
+
+	return netfs_unpin_writeback(inode, wbc);
+}
+
+static const struct super_operations v9fs_super_ops = {
+	.alloc_inode = v9fs_alloc_inode,
+	.free_inode = v9fs_free_inode,
+	.statfs = simple_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,
+};
+
+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,
+};
+
+static void v9fs_free_fc(struct fs_context *fc)
+{
+	struct v9fs_context *ctx = fc->fs_private;
+
+	if (!ctx)
+		return;
+
+	/* These should be NULL by now but guard against leaks */
+	kfree(ctx->session_opts.uname);
+	kfree(ctx->session_opts.aname);
+#ifdef CONFIG_9P_FSCACHE
+	kfree(ctx->session_opts.cachetag);
+#endif
+	if (ctx->client_opts.trans_mod)
+		v9fs_put_trans(ctx->client_opts.trans_mod);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations v9fs_context_ops = {
+	.parse_param	= v9fs_parse_param,
+	.get_tree	= v9fs_get_tree,
+	.free		= v9fs_free_fc,
+};
+
+static int v9fs_init_fs_context(struct fs_context *fc)
+{
+	struct v9fs_context	*ctx;
+
+	ctx = kzalloc_obj(*ctx);
+	if (!ctx)
+		return -ENOMEM;
+
+	fc->ops = &v9fs_context_ops;
+	fc->fs_private = ctx;
+
+	/* initialize core options */
+	ctx->session_opts.afid = ~0;
+	ctx->session_opts.cache = CACHE_NONE;
+	ctx->session_opts.session_lock_timeout = P9_LOCK_TIMEOUT;
+	ctx->session_opts.uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
+	if (!ctx->session_opts.uname)
+		goto error;
+
+	ctx->session_opts.aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
+	if (!ctx->session_opts.aname)
+		goto error;
+
+	ctx->session_opts.uid = INVALID_UID;
+	ctx->session_opts.dfltuid = V9FS_DEFUID;
+	ctx->session_opts.dfltgid = V9FS_DEFGID;
+	ctx->session_opts.ndentry_timeout_ms = 0;
+
+	/* initialize client options */
+	ctx->client_opts.proto_version = p9_proto_2000L;
+	ctx->client_opts.msize = DEFAULT_MSIZE;
+
+	/* initialize fd transport options */
+	ctx->fd_opts.port = P9_FD_PORT;
+	ctx->fd_opts.rfd = ~0;
+	ctx->fd_opts.wfd = ~0;
+	ctx->fd_opts.privport = false;
+
+	/* initialize rdma transport options */
+	ctx->rdma_opts.port = P9_RDMA_PORT;
+	ctx->rdma_opts.sq_depth = P9_RDMA_SQ_DEPTH;
+	ctx->rdma_opts.rq_depth = P9_RDMA_RQ_DEPTH;
+	ctx->rdma_opts.timeout = P9_RDMA_TIMEOUT;
+	ctx->rdma_opts.privport = false;
+
+	return 0;
+error:
+	fc->need_free = 1;
+	return -ENOMEM;
+}
+
+struct file_system_type v9fs_fs_type = {
+	.name = "9p",
+	.kill_sb = v9fs_kill_super,
+	.owner = THIS_MODULE,
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
+	.init_fs_context = v9fs_init_fs_context,
+	.parameters = v9fs_param_spec,
+};
+MODULE_ALIAS_FS("9p");