Adding upstream version 1:2.3.21+dfsg1.upstream/1%2.3.21+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 108 insertions, 0 deletions

diff --git a/src/lib/file-set-size.c b/src/lib/file-set-size.c
new file mode 100644
index 0000000..1f5938f
--- /dev/null
+++ b/src/lib/file-set-size.c
@@ -0,0 +1,108 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#ifdef HAVE_POSIX_FALLOCATE
+#  define _XOPEN_SOURCE 600 /* Required by glibc, breaks Solaris 9 */
+#endif
+#define _GNU_SOURCE /* for fallocate() */
+#include "lib.h"
+#include "file-set-size.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#if defined(HAVE_LINUX_FALLOC_H) && !defined(FALLOC_FL_KEEP_SIZE)
+/* Legacy Linux does not have the FALLOC_FL_* flags under fcntl.h */
+#  include <linux/falloc.h>
+#endif
+
+int file_set_size(int fd, off_t size)
+{
+#ifdef HAVE_POSIX_FALLOCATE
+	static bool posix_fallocate_supported = TRUE;
+#endif
+	char block[IO_BLOCK_SIZE];
+	off_t offset;
+	ssize_t ret;
+	struct stat st;
+
+	i_assert(size >= 0);
+
+	if (fstat(fd, &st) < 0) {
+		i_error("fstat() failed: %m");
+		return -1;
+	}
+
+	if (size < st.st_size) {
+		if (ftruncate(fd, size) < 0) {
+			i_error("ftruncate() failed: %m");
+			return -1;
+		}
+		return 0;
+	}
+	if (size == st.st_size)
+		return 0;
+
+#ifdef HAVE_POSIX_FALLOCATE
+	if (posix_fallocate_supported) {
+		int err;
+
+		err = posix_fallocate(fd, st.st_size, size - st.st_size);
+		if (err == 0)
+			return 0;
+
+		if (err != EINVAL /* Solaris */ &&
+		    err != EOPNOTSUPP /* AOX */) {
+			if (!ENOSPACE(err))
+				i_error("posix_fallocate() failed: %m");
+			return -1;
+		}
+		/* Not supported by kernel, fallback to writing. */
+		posix_fallocate_supported = FALSE;
+	}
+#endif
+	/* start growing the file */
+	offset = st.st_size;
+	memset(block, 0, I_MIN((ssize_t)sizeof(block), size - offset));
+
+	while (offset < size) {
+		ret = pwrite(fd, block,
+			     I_MIN((ssize_t)sizeof(block), size - offset),
+			     offset);
+		if (ret < 0) {
+			if (!ENOSPACE(errno))
+				i_error("pwrite() failed: %m");
+			return -1;
+		}
+		offset += ret;
+	}
+	return 0;
+}
+
+int file_preallocate(int fd ATTR_UNUSED, off_t size ATTR_UNUSED)
+{
+#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_KEEP_SIZE)
+	/* Linux */
+	if (fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, size) < 0)
+		return errno == ENOSYS ? 0 : -1;
+	return 1;
+#elif defined (F_PREALLOCATE)
+	/* OSX */
+	fstore_t fs;
+
+	i_zero(&fs);
+	fs.fst_flags = F_ALLOCATECONTIG;
+	fs.fst_posmode = F_PEOFPOSMODE;
+	fs.fst_offset = 0;
+	fs.fst_length = size;
+	fs.fst_bytesalloc = 0;
+	if (fcntl(fd, F_PREALLOCATE, &fs) < 0)
+		return -1;
+	return fs.fst_bytesalloc > 0 ? 1 : 0;
+#else
+	return 0;
+#endif
+}