[PATCH v4 2/3] vfs: call vfs_clone_file_range() under mnt_want_write()
From: Amir Goldstein <amir73il@gmail.com>
Date: 2016-09-23 08:38:51
Also in:
linux-fsdevel, linux-unionfs
Subsystem:
filesystems (vfs and infrastructure), landlock security module, the rest · Maintainers:
Alexander Viro, Christian Brauner, Mickaël Salaün, Linus Torvalds
Move mnt_want_write() out of the vfs helper and up into the ioctl handler. Taking mnt_want_write() outside the vfs helper is the standard in most namei.c syscalls. This change will allow overlayfs code to use the helper for copy up. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/ioctl.c | 9 +++++++++ fs/read_write.c | 5 ----- 2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 34d2994..9299832 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c@@ -15,6 +15,7 @@ #include <linux/writeback.h> #include <linux/buffer_head.h> #include <linux/falloc.h> +#include <linux/mount.h> #include "internal.h" #include <asm/ioctls.h>
@@ -225,7 +226,15 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd, return -EBADF; if (src_file.file->f_path.mnt != dst_file->f_path.mnt) return -EXDEV; + + ret = mnt_want_write_file(dst_file); + if (ret) + goto out_fput; + ret = vfs_clone_file_range(src_file.file, off, dst_file, destoff, olen); + + mnt_drop_write_file(dst_file); +out_fput: fdput(src_file); return ret; }
diff --git a/fs/read_write.c b/fs/read_write.c
index 9dc6e52..90bc18b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c@@ -1660,10 +1660,6 @@ int vfs_clone_file_range(struct file *file_in, loff_t pos_in, if (pos_in + len > i_size_read(inode_in)) return -EINVAL; - ret = mnt_want_write_file(file_out); - if (ret) - return ret; - ret = file_in->f_op->clone_file_range(file_in, pos_in, file_out, pos_out, len); if (!ret) {
@@ -1671,7 +1667,6 @@ int vfs_clone_file_range(struct file *file_in, loff_t pos_in, fsnotify_modify(file_out); } - mnt_drop_write_file(file_out); return ret; } EXPORT_SYMBOL(vfs_clone_file_range);
--
2.7.4