Merge tag 'fuse-update-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fix regression in fileattr permission checking

 - Fix possible hang during PID namespace destruction

 - Add generic support for request extensions

 - Add supplementary group list extension

 - Add limited support for supplying supplementary groups in create
   requests

 - Documentation fixes

* tag 'fuse-update-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add inode/permission checks to fileattr_get/fileattr_set
  fuse: fix all W=1 kernel-doc warnings
  fuse: in fuse_flush only wait if someone wants the return code
  fuse: optional supplementary group in create requests
  fuse: add request extension

1 files changed, 64 insertions, 27 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index ff0b3ef774d4..de37a3a06a71 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -19,6 +19,7 @@
 #include <linux/uio.h>
 #include <linux/fs.h>
 #include <linux/filelock.h>
+#include <linux/file.h>
 
 static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
 			  unsigned int open_flags, int opcode,
@@ -478,48 +479,36 @@ static void fuse_sync_writes(struct inode *inode)
 	fuse_release_nowrite(inode);
 }
 
-static int fuse_flush(struct file *file, fl_owner_t id)
-{
-	struct inode *inode = file_inode(file);
-	struct fuse_mount *fm = get_fuse_mount(inode);
-	struct fuse_file *ff = file->private_data;
+struct fuse_flush_args {
+	struct fuse_args args;
 	struct fuse_flush_in inarg;
-	FUSE_ARGS(args);
-	int err;
-
-	if (fuse_is_bad(inode))
-		return -EIO;
+	struct work_struct work;
+	struct file *file;
+};
 
-	if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
-		return 0;
+static int fuse_do_flush(struct fuse_flush_args *fa)
+{
+	int err;
+	struct inode *inode = file_inode(fa->file);
+	struct fuse_mount *fm = get_fuse_mount(inode);
 
 	err = write_inode_now(inode, 1);
 	if (err)
-		return err;
+		goto out;
 
 	inode_lock(inode);
 	fuse_sync_writes(inode);
 	inode_unlock(inode);
 
-	err = filemap_check_errors(file->f_mapping);
+	err = filemap_check_errors(fa->file->f_mapping);
 	if (err)
-		return err;
+		goto out;
 
 	err = 0;
 	if (fm->fc->no_flush)
 		goto inval_attr_out;
 
-	memset(&inarg, 0, sizeof(inarg));
-	inarg.fh = ff->fh;
-	inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
-	args.opcode = FUSE_FLUSH;
-	args.nodeid = get_node_id(inode);
-	args.in_numargs = 1;
-	args.in_args[0].size = sizeof(inarg);
-	args.in_args[0].value = &inarg;
-	args.force = true;
-
-	err = fuse_simple_request(fm, &args);
+	err = fuse_simple_request(fm, &fa->args);
 	if (err == -ENOSYS) {
 		fm->fc->no_flush = 1;
 		err = 0;
@@ -532,9 +521,57 @@ inval_attr_out:
 	 */
 	if (!err && fm->fc->writeback_cache)
 		fuse_invalidate_attr_mask(inode, STATX_BLOCKS);
+
+out:
+	fput(fa->file);
+	kfree(fa);
 	return err;
 }
 
+static void fuse_flush_async(struct work_struct *work)
+{
+	struct fuse_flush_args *fa = container_of(work, typeof(*fa), work);
+
+	fuse_do_flush(fa);
+}
+
+static int fuse_flush(struct file *file, fl_owner_t id)
+{
+	struct fuse_flush_args *fa;
+	struct inode *inode = file_inode(file);
+	struct fuse_mount *fm = get_fuse_mount(inode);
+	struct fuse_file *ff = file->private_data;
+
+	if (fuse_is_bad(inode))
+		return -EIO;
+
+	if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
+		return 0;
+
+	fa = kzalloc(sizeof(*fa), GFP_KERNEL);
+	if (!fa)
+		return -ENOMEM;
+
+	fa->inarg.fh = ff->fh;
+	fa->inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
+	fa->args.opcode = FUSE_FLUSH;
+	fa->args.nodeid = get_node_id(inode);
+	fa->args.in_numargs = 1;
+	fa->args.in_args[0].size = sizeof(fa->inarg);
+	fa->args.in_args[0].value = &fa->inarg;
+	fa->args.force = true;
+	fa->file = get_file(file);
+
+	/* Don't wait if the task is exiting */
+	if (current->flags & PF_EXITING) {
+		INIT_WORK(&fa->work, fuse_flush_async);
+		schedule_work(&fa->work);
+		return 0;
+	}
+
+	return fuse_do_flush(fa);
+}
+
 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 		      int datasync, int opcode)
 {
@@ -653,7 +690,7 @@ static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io)
 	return io->bytes < 0 ? io->size : io->bytes;
 }
 
-/**
+/*
  * In case of short read, the caller sets 'pos' to the position of
  * actual end of fuse request in IO request. Otherwise, if bytes_requested
  * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.