Merge tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs update from Miklos Szeredi:

 - Try to preserve holes in sparse files when copying up, thus saving
   disk space and improving performance.

 - Fix a performance regression introduced in v4.19 by preserving
   asynchronicity of IO when fowarding to underlying layers. Add VFS
   helpers to submit async iocbs.

 - Fix a regression in lseek(2) introduced in v4.19 that breaks >2G
   seeks on 32bit kernels.

 - Fix a corner case where st_ino/st_dev was not preserved across copy
   up.

 - Miscellaneous fixes and cleanups.

* tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix lseek overflow on 32bit
  ovl: add splice file read write helper
  ovl: implement async IO routines
  vfs: add vfs_iocb_iter_[read|write] helper functions
  ovl: layer is const
  ovl: fix corner case of non-constant st_dev;st_ino
  ovl: fix corner case of conflicting lower layer uuid
  ovl: generalize the lower_fs[] array
  ovl: simplify ovl_same_sb() helper
  ovl: generalize the lower_layers[] array
  ovl: improving copy-up efficiency for big sparse file
  ovl: use ovl_inode_lock in ovl_llseek()
  ovl: use pr_fmt auto generate prefix
  ovl: fix wrong WARN_ON() in ovl_cache_update_ino()

1 files changed, 56 insertions, 0 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index 7458fccc59e1..59d819c5b92e 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -939,6 +939,34 @@ out:
 	return ret;
 }
 
+ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
+			   struct iov_iter *iter)
+{
+	size_t tot_len;
+	ssize_t ret = 0;
+
+	if (!file->f_op->read_iter)
+		return -EINVAL;
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!(file->f_mode & FMODE_CAN_READ))
+		return -EINVAL;
+
+	tot_len = iov_iter_count(iter);
+	if (!tot_len)
+		goto out;
+	ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);
+	if (ret < 0)
+		return ret;
+
+	ret = call_read_iter(file, iocb, iter);
+out:
+	if (ret >= 0)
+		fsnotify_access(file);
+	return ret;
+}
+EXPORT_SYMBOL(vfs_iocb_iter_read);
+
 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
 		rwf_t flags)
 {
@@ -975,6 +1003,34 @@ static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
 	return ret;
 }
 
+ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
+			    struct iov_iter *iter)
+{
+	size_t tot_len;
+	ssize_t ret = 0;
+
+	if (!file->f_op->write_iter)
+		return -EINVAL;
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
+	if (!(file->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
+
+	tot_len = iov_iter_count(iter);
+	if (!tot_len)
+		return 0;
+	ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
+	if (ret < 0)
+		return ret;
+
+	ret = call_write_iter(file, iocb, iter);
+	if (ret > 0)
+		fsnotify_modify(file);
+
+	return ret;
+}
+EXPORT_SYMBOL(vfs_iocb_iter_write);
+
 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
 		rwf_t flags)
 {