From 7f9caa4a3698827010d9b478407d21dd58b8bca5 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Mon, 27 Nov 2023 21:14:49 +0100 Subject: Cygwin: open(2): reset sparseness on O_TRUNCated files open(2) implements O_TRUNC by just reducing the size of the file to 0, to make sure EAs stay available. Turns out, file sparseness is not removed this way either, so add code to do just that. Fixes: 603ef545bdbd ("* fhandler.cc (fhandler_base::open): Never open files with FILE_OVERWITE/FILE_OVERWRITE_IF.") Signed-off-by: Corinna Vinschen --- winsup/cygwin/fhandler/base.cc | 9 +++++++++ winsup/cygwin/release/3.4.10 | 3 +++ 2 files changed, 12 insertions(+) (limited to 'winsup') diff --git a/winsup/cygwin/fhandler/base.cc b/winsup/cygwin/fhandler/base.cc index d859870cb..b93366254 100644 --- a/winsup/cygwin/fhandler/base.cc +++ b/winsup/cygwin/fhandler/base.cc @@ -776,6 +776,15 @@ fhandler_base::open (int flags, mode_t mode) NtClose (fh); goto done; } + /* Drop sparseness */ + if (pc.file_attributes () & FILE_ATTRIBUTE_SPARSE_FILE) + { + FILE_SET_SPARSE_BUFFER fssb = { SetSparse: FALSE }; + status = NtFsControlFile (fh, NULL, NULL, NULL, &io, + FSCTL_SET_SPARSE, &fssb, sizeof fssb, NULL, 0); + if (NT_SUCCESS (status)) + pc.file_attributes (pc.file_attributes () & ~FILE_ATTRIBUTE_SPARSE_FILE); + } } set_handle (fh); diff --git a/winsup/cygwin/release/3.4.10 b/winsup/cygwin/release/3.4.10 index 02f688583..632ffcd39 100644 --- a/winsup/cygwin/release/3.4.10 +++ b/winsup/cygwin/release/3.4.10 @@ -21,3 +21,6 @@ Bug Fixes - Fix posix_fallocate(3) return value in case of being called on other than regular files. + +- Reset sparseness in case open(2) has been called with O_CREAT|O_TRUNC on + sparse files. -- cgit v1.2.3