From 10bc8e4af65946b727728d7479c028742321b60a Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 17 Nov 2022 22:52:49 +0200 Subject: vfs: fix copy_file_range() averts filesystem freeze protection Commit 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs copies") removed fallback to generic_copy_file_range() for cross-fs cases inside vfs_copy_file_range(). To preserve behavior of nfsd and ksmbd server-side-copy, the fallback to generic_copy_file_range() was added in nfsd and ksmbd code, but that call is missing sb_start_write(), fsnotify hooks and more. Ideally, nfsd and ksmbd would pass a flag to vfs_copy_file_range() that will take care of the fallback, but that code would be subtle and we got vfs_copy_file_range() logic wrong too many times already. Instead, add a flag to explicitly request vfs_copy_file_range() to perform only generic_copy_file_range() and let nfsd and ksmbd use this flag only in the fallback path. This choise keeps the logic changes to minimum in the non-nfsd/ksmbd code paths to reduce the risk of further regressions. Fixes: 868f9f2f8e00 ("vfs: fix copy_file_range() regression in cross-fs copies") Tested-by: Namjae Jeon Tested-by: Luis Henriques Signed-off-by: Amir Goldstein Signed-off-by: Al Viro --- include/linux/fs.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index e654435f1651..59ae95ddb679 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2089,6 +2089,14 @@ struct dir_context { */ #define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN) +/* + * These flags control the behavior of vfs_copy_file_range(). + * They are not available to the user via syscall. + * + * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops + */ +#define COPY_FILE_SPLICE (1 << 0) + struct iov_iter; struct io_uring_cmd; -- cgit