Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 225 insertions, 0 deletions

diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
new file mode 100644
index 000000000..bbb2c210d
--- /dev/null
+++ b/fs/afs/mntpt.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* mountpoint management
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/gfp.h>
+#include <linux/fs_context.h>
+#include "internal.h"
+
+
+static struct dentry *afs_mntpt_lookup(struct inode *dir,
+				       struct dentry *dentry,
+				       unsigned int flags);
+static int afs_mntpt_open(struct inode *inode, struct file *file);
+static void afs_mntpt_expiry_timed_out(struct work_struct *work);
+
+const struct file_operations afs_mntpt_file_operations = {
+	.open		= afs_mntpt_open,
+	.llseek		= noop_llseek,
+};
+
+const struct inode_operations afs_mntpt_inode_operations = {
+	.lookup		= afs_mntpt_lookup,
+	.readlink	= page_readlink,
+	.getattr	= afs_getattr,
+};
+
+const struct inode_operations afs_autocell_inode_operations = {
+	.getattr	= afs_getattr,
+};
+
+static LIST_HEAD(afs_vfsmounts);
+static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out);
+
+static unsigned long afs_mntpt_expiry_timeout = 10 * 60;
+
+static const char afs_root_volume[] = "root.cell";
+
+/*
+ * no valid lookup procedure on this sort of dir
+ */
+static struct dentry *afs_mntpt_lookup(struct inode *dir,
+				       struct dentry *dentry,
+				       unsigned int flags)
+{
+	_enter("%p,%p{%pd2}", dir, dentry, dentry);
+	return ERR_PTR(-EREMOTE);
+}
+
+/*
+ * no valid open procedure on this sort of dir
+ */
+static int afs_mntpt_open(struct inode *inode, struct file *file)
+{
+	_enter("%p,%p{%pD2}", inode, file, file);
+	return -EREMOTE;
+}
+
+/*
+ * Set the parameters for the proposed superblock.
+ */
+static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
+{
+	struct afs_fs_context *ctx = fc->fs_private;
+	struct afs_super_info *src_as = AFS_FS_S(mntpt->d_sb);
+	struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt));
+	struct afs_cell *cell;
+	const char *p;
+	int ret;
+
+	if (fc->net_ns != src_as->net_ns) {
+		put_net(fc->net_ns);
+		fc->net_ns = get_net(src_as->net_ns);
+	}
+
+	if (src_as->volume && src_as->volume->type == AFSVL_RWVOL) {
+		ctx->type = AFSVL_RWVOL;
+		ctx->force = true;
+	}
+	if (ctx->cell) {
+		afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_mntpt);
+		ctx->cell = NULL;
+	}
+	if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
+		/* if the directory is a pseudo directory, use the d_name */
+		unsigned size = mntpt->d_name.len;
+
+		if (size < 2)
+			return -ENOENT;
+
+		p = mntpt->d_name.name;
+		if (mntpt->d_name.name[0] == '.') {
+			size--;
+			p++;
+			ctx->type = AFSVL_RWVOL;
+			ctx->force = true;
+		}
+		if (size > AFS_MAXCELLNAME)
+			return -ENAMETOOLONG;
+
+		cell = afs_lookup_cell(ctx->net, p, size, NULL, false);
+		if (IS_ERR(cell)) {
+			pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt);
+			return PTR_ERR(cell);
+		}
+		ctx->cell = cell;
+
+		ctx->volname = afs_root_volume;
+		ctx->volnamesz = sizeof(afs_root_volume) - 1;
+	} else {
+		/* read the contents of the AFS special symlink */
+		struct page *page;
+		loff_t size = i_size_read(d_inode(mntpt));
+		char *buf;
+
+		if (src_as->cell)
+			ctx->cell = afs_use_cell(src_as->cell, afs_cell_trace_use_mntpt);
+
+		if (size < 2 || size > PAGE_SIZE - 1)
+			return -EINVAL;
+
+		page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		if (PageError(page)) {
+			ret = afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt);
+			put_page(page);
+			return ret;
+		}
+
+		buf = kmap(page);
+		ret = -EINVAL;
+		if (buf[size - 1] == '.')
+			ret = vfs_parse_fs_string(fc, "source", buf, size - 1);
+		kunmap(page);
+		put_page(page);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * create a vfsmount to be automounted
+ */
+static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
+{
+	struct fs_context *fc;
+	struct vfsmount *mnt;
+	int ret;
+
+	BUG_ON(!d_inode(mntpt));
+
+	fc = fs_context_for_submount(&afs_fs_type, mntpt);
+	if (IS_ERR(fc))
+		return ERR_CAST(fc);
+
+	ret = afs_mntpt_set_params(fc, mntpt);
+	if (!ret)
+		mnt = fc_mount(fc);
+	else
+		mnt = ERR_PTR(ret);
+
+	put_fs_context(fc);
+	return mnt;
+}
+
+/*
+ * handle an automount point
+ */
+struct vfsmount *afs_d_automount(struct path *path)
+{
+	struct vfsmount *newmnt;
+
+	_enter("{%pd}", path->dentry);
+
+	newmnt = afs_mntpt_do_automount(path->dentry);
+	if (IS_ERR(newmnt))
+		return newmnt;
+
+	mntget(newmnt); /* prevent immediate expiration */
+	mnt_set_expiry(newmnt, &afs_vfsmounts);
+	queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
+			   afs_mntpt_expiry_timeout * HZ);
+	_leave(" = %p", newmnt);
+	return newmnt;
+}
+
+/*
+ * handle mountpoint expiry timer going off
+ */
+static void afs_mntpt_expiry_timed_out(struct work_struct *work)
+{
+	_enter("");
+
+	if (!list_empty(&afs_vfsmounts)) {
+		mark_mounts_for_expiry(&afs_vfsmounts);
+		queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
+				   afs_mntpt_expiry_timeout * HZ);
+	}
+
+	_leave("");
+}
+
+/*
+ * kill the AFS mountpoint timer if it's still running
+ */
+void afs_mntpt_kill_timer(void)
+{
+	_enter("");
+
+	ASSERT(list_empty(&afs_vfsmounts));
+	cancel_delayed_work_sync(&afs_mntpt_expiry_timer);
+}