From: Martin Wilck <mwilck@xxxxxxxx>
Save code and syscalls by assembling the content in memory first.
write() may return less bytes written than expected. Deal with it.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/alias.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/libmultipath/alias.c b/libmultipath/alias.c
index 76d852f..c26f37c 100644
--- a/libmultipath/alias.c
+++ b/libmultipath/alias.c
@@ -118,22 +118,30 @@ static int add_binding(Bindings *bindings, const char *alias, const char *wwid)
static int write_bindings_file(const Bindings *bindings, int fd)
{
struct binding *bnd;
- STRBUF_ON_STACK(line);
+ STRBUF_ON_STACK(content);
int i;
+ size_t len;
- if (write(fd, BINDINGS_FILE_HEADER, sizeof(BINDINGS_FILE_HEADER) - 1)
- != sizeof(BINDINGS_FILE_HEADER) - 1)
+ if (__append_strbuf_str(&content, BINDINGS_FILE_HEADER,
+ sizeof(BINDINGS_FILE_HEADER) - 1) == -1)
return -1;
vector_foreach_slot(bindings, bnd, i) {
- int len;
+ if (print_strbuf(&content, "%s %s\n",
+ bnd->alias, bnd->wwid) < 0)
+ return -1;
+ }
+ len = get_strbuf_len(&content);
+ while (len > 0) {
+ ssize_t n = write(fd, get_strbuf_str(&content), len);
- if ((len = print_strbuf(&line, "%s %s\n",
- bnd->alias, bnd->wwid)) < 0)
+ if (n < 0)
+ return n;
+ else if (n == 0) {
+ condlog(2, "%s: short write", __func__);
return -1;
- if (write(fd, get_strbuf_str(&line), len) != len)
- return -1;
- truncate_strbuf(&line, 0);
+ }
+ len -= n;
}
return 0;
}
--
2.41.0
--
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