shadow/backport-More-robust-file-content-copy-in-copy_tree.patch
qsw33 40d22c3533 backport some patches
(cherry picked from commit 6f859a83e8b96a406cdbdd0b679bc4009f870183)
2023-11-13 22:38:12 +08:00

99 lines
2.2 KiB
Diff

From f606314f0c22fb5d13e5af17a70860d57559e808 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Fri, 5 Aug 2022 17:57:27 +0200
Subject: [PATCH] More robust file content copy in copy_tree()
Bail out on read(2) failure, continue on EINTR, support short writes and
increase chunk size.
Conflict: NA
Reference: https://github.com/shadow-maint/shadow/commit/f606314f0c22fb5d13e5af17a70860d57559e808
---
libmisc/copydir.c | 58 +++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 54 insertions(+), 4 deletions(-)
diff --git a/libmisc/copydir.c b/libmisc/copydir.c
index 90895cfb0..95042187b 100644
--- a/libmisc/copydir.c
+++ b/libmisc/copydir.c
@@ -691,6 +691,42 @@ static int copy_special (const char *src, const char *dst,
return err;
}
+/*
+ * full_write - write entire buffer
+ *
+ * Write up to count bytes from the buffer starting at buf to the
+ * file referred to by the file descriptor fd.
+ * Retry in case of a short write.
+ *
+ * Returns the number of bytes written on success, -1 on error.
+ */
+static ssize_t full_write(int fd, const void *buf, size_t count) {
+ ssize_t written = 0;
+
+ while (count > 0) {
+ ssize_t res;
+
+ res = write(fd, buf, count);
+ if (res < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+
+ return res;
+ }
+
+ if (res == 0) {
+ break;
+ }
+
+ written += res;
+ buf = (const unsigned char*)buf + res;
+ count -= (size_t)res;
+ }
+
+ return written;
+}
+
/*
* copy_file - copy a file
*
@@ -710,8 +746,6 @@ static int copy_file (const char *src, const char *dst,
int err = 0;
int ifd;
int ofd;
- char buf[1024];
- ssize_t cnt;
ifd = open (src, O_RDONLY|O_NOFOLLOW);
if (ifd < 0) {
@@ -753,8 +787,24 @@ static int copy_file (const char *src, const char *dst,
return -1;
}
- while ((cnt = read (ifd, buf, sizeof buf)) > 0) {
- if (write (ofd, buf, (size_t)cnt) != cnt) {
+ while (true) {
+ char buf[8192];
+ ssize_t cnt;
+
+ cnt = read (ifd, buf, sizeof buf);
+ if (cnt < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ (void) close (ofd);
+ (void) close (ifd);
+ return -1;
+ }
+ if (cnt == 0) {
+ break;
+ }
+
+ if (full_write (ofd, buf, (size_t)cnt) < 0) {
(void) close (ofd);
(void) close (ifd);
return -1;