Merge tag 'fuse-update-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fixes for virtiofs submounts

 - Misc fixes and cleanups

* tag 'fuse-update-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  virtiofs: Fix spelling mistakes
  fuse: use DIV_ROUND_UP helper macro for calculations
  fuse: fix illegal access to inode with reused nodeid
  fuse: allow fallocate(FALLOC_FL_ZERO_RANGE)
  fuse: Make fuse_fill_super_submount() static
  fuse: Switch to fc_mount() for submounts
  fuse: Call vfs_get_tree() for submounts
  fuse: add dedicated filesystem context ops for submounts
  virtiofs: propagate sync() to file server
  fuse: reject internal errno
  fuse: check connected before queueing on fpq->io
  fuse: ignore PG_workingset after stealing
  fuse: Fix infinite loop in sget_fc()
  fuse: Fix crash if superblock of submount gets killed early
  fuse: Fix crash in fuse_dentry_automount() error path

1 files changed, 96 insertions, 4 deletions

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 393e36b74dc4..b9beb39a4a18 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -350,8 +350,8 @@ retry:
 		inode->i_generation = generation;
 		fuse_init_inode(inode, attr);
 		unlock_new_inode(inode);
-	} else if (inode_wrong_type(inode, attr->mode)) {
-		/* Inode has changed type, any I/O on the old should fail */
+	} else if (fuse_stale_inode(inode, generation, attr)) {
+		/* nodeid was reused, any I/O on the old inode should fail */
 		fuse_make_bad(inode);
 		iput(inode);
 		goto retry;
@@ -506,6 +506,45 @@ static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return err;
 }
 
+static int fuse_sync_fs(struct super_block *sb, int wait)
+{
+	struct fuse_mount *fm = get_fuse_mount_super(sb);
+	struct fuse_conn *fc = fm->fc;
+	struct fuse_syncfs_in inarg;
+	FUSE_ARGS(args);
+	int err;
+
+	/*
+	 * Userspace cannot handle the wait == 0 case.  Avoid a
+	 * gratuitous roundtrip.
+	 */
+	if (!wait)
+		return 0;
+
+	/* The filesystem is being unmounted.  Nothing to do. */
+	if (!sb->s_root)
+		return 0;
+
+	if (!fc->sync_fs)
+		return 0;
+
+	memset(&inarg, 0, sizeof(inarg));
+	args.in_numargs = 1;
+	args.in_args[0].size = sizeof(inarg);
+	args.in_args[0].value = &inarg;
+	args.opcode = FUSE_SYNCFS;
+	args.nodeid = get_node_id(sb->s_root->d_inode);
+	args.out_numargs = 0;
+
+	err = fuse_simple_request(fm, &args);
+	if (err == -ENOSYS) {
+		fc->sync_fs = 0;
+		err = 0;
+	}
+
+	return err;
+}
+
 enum {
 	OPT_SOURCE,
 	OPT_SUBTYPE,
@@ -909,6 +948,7 @@ static const struct super_operations fuse_super_operations = {
 	.put_super	= fuse_put_super,
 	.umount_begin	= fuse_umount_begin,
 	.statfs		= fuse_statfs,
+	.sync_fs	= fuse_sync_fs,
 	.show_options	= fuse_show_options,
 };
 
@@ -1275,8 +1315,8 @@ static void fuse_sb_defaults(struct super_block *sb)
 		sb->s_xattr = fuse_no_acl_xattr_handlers;
 }
 
-int fuse_fill_super_submount(struct super_block *sb,
-			     struct fuse_inode *parent_fi)
+static int fuse_fill_super_submount(struct super_block *sb,
+				    struct fuse_inode *parent_fi)
 {
 	struct fuse_mount *fm = get_fuse_mount_super(sb);
 	struct super_block *parent_sb = parent_fi->inode.i_sb;
@@ -1313,6 +1353,58 @@ int fuse_fill_super_submount(struct super_block *sb,
 	return 0;
 }
 
+/* Filesystem context private data holds the FUSE inode of the mount point */
+static int fuse_get_tree_submount(struct fs_context *fsc)
+{
+	struct fuse_mount *fm;
+	struct fuse_inode *mp_fi = fsc->fs_private;
+	struct fuse_conn *fc = get_fuse_conn(&mp_fi->inode);
+	struct super_block *sb;
+	int err;
+
+	fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
+	if (!fm)
+		return -ENOMEM;
+
+	fsc->s_fs_info = fm;
+	sb = sget_fc(fsc, NULL, set_anon_super_fc);
+	if (IS_ERR(sb)) {
+		kfree(fm);
+		return PTR_ERR(sb);
+	}
+	fm->fc = fuse_conn_get(fc);
+
+	/* Initialize superblock, making @mp_fi its root */
+	err = fuse_fill_super_submount(sb, mp_fi);
+	if (err) {
+		fuse_conn_put(fc);
+		kfree(fm);
+		sb->s_fs_info = NULL;
+		deactivate_locked_super(sb);
+		return err;
+	}
+
+	down_write(&fc->killsb);
+	list_add_tail(&fm->fc_entry, &fc->mounts);
+	up_write(&fc->killsb);
+
+	sb->s_flags |= SB_ACTIVE;
+	fsc->root = dget(sb->s_root);
+
+	return 0;
+}
+
+static const struct fs_context_operations fuse_context_submount_ops = {
+	.get_tree	= fuse_get_tree_submount,
+};
+
+int fuse_init_fs_context_submount(struct fs_context *fsc)
+{
+	fsc->ops = &fuse_context_submount_ops;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount);
+
 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
 {
 	struct fuse_dev *fud = NULL;