[RFC PATCH 15/35] ovl: readd fallocate

From: Miklos Szeredi
Date: Thu Apr 12 2018 - 11:20:24 EST


Implement stacked fallocate.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/overlayfs/file.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index f1cc2fdc62c1..05e3e2f80b89 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -268,6 +268,29 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
return ret;
}

+long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct fd real;
+ const struct cred *old_cred;
+ int ret;
+
+ ret = ovl_real_file(file, &real);
+ if (ret)
+ return ret;
+
+ old_cred = ovl_override_creds(file_inode(file)->i_sb);
+ ret = vfs_fallocate(real.file, mode, offset, len);
+ revert_creds(old_cred);
+
+ /* Update size */
+ ovl_copyattr(ovl_inode_real(inode), inode);
+
+ fdput(real);
+
+ return ret;
+}
+
const struct file_operations ovl_file_operations = {
.open = ovl_open,
.release = ovl_release,
@@ -276,4 +299,5 @@ const struct file_operations ovl_file_operations = {
.write_iter = ovl_write_iter,
.fsync = ovl_fsync,
.mmap = ovl_mmap,
+ .fallocate = ovl_fallocate,
};
--
2.14.3