From: Karel Zak <kzak@redhat.com>
Date: Tue, 28 Jan 2025 12:13:02 +0000 (+0100)
Subject: libmount: add private mnt_context_read_mesgs()
X-Git-Tag: v2.42-start~64^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8369f2a7c46df5b4813f39c5f2f1e60c35500f75;p=thirdparty%2Futil-linux.git

libmount: add private mnt_context_read_mesgs()

Add a more generic function for reading messages from a file
descriptor. The new mount API is already used in multiple files.

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libmount/src/context.c b/libmount/src/context.c
index a3bc33ab9..3c1258882 100644
--- a/libmount/src/context.c
+++ b/libmount/src/context.c
@@ -2729,6 +2729,9 @@ void mnt_context_reset_mesgs(struct libmnt_context *cxt)
 
 int mnt_context_append_mesg(struct libmnt_context *cxt, const char *msg)
 {
+	if (msg) {
+		DBG(CXT, ul_debug("mesg: '%s'", msg));
+	}
 	return strv_extend(&cxt->mesgs, msg);
 }
 
@@ -2744,6 +2747,36 @@ int mnt_context_sprintf_mesg(struct libmnt_context *cxt, const char *msg, ...)
 	return rc;
 }
 
+int mnt_context_read_mesgs(struct libmnt_context *cxt, int fd)
+{
+	uint8_t buf[BUFSIZ];
+	ssize_t sz;
+	size_t count = 0;
+	int errsv = errno;
+
+	if (fd < 0)
+		return 0;
+
+	while ((sz = read(fd, buf, sizeof(buf) - 1)) != -1) {
+
+		if (sz <= 0)
+			continue;
+		if (buf[sz - 1] == '\n')
+			buf[--sz] = '\0';
+		else
+			buf[sz] = '\0';
+
+		if (!*buf)
+			continue;
+
+		mnt_context_append_mesg(cxt, (char *) buf);
+		count++;;
+	}
+
+	errno = errsv;
+	return count;
+}
+
 /**
  * mnt_context_get_nmesgs:
  * @cxt: mount context
diff --git a/libmount/src/hook_mount.c b/libmount/src/hook_mount.c
index e128c4a68..1ffd19e83 100644
--- a/libmount/src/hook_mount.c
+++ b/libmount/src/hook_mount.c
@@ -62,25 +62,6 @@ static void close_sysapi_fds(struct libmnt_sysapi *api)
 	api->fd_tree = api->fd_fs = -1;
 }
 
-static void save_fd_messages(struct libmnt_context *cxt, int fd)
-{
-	uint8_t buf[BUFSIZ];
-	int rc;
-
-	while ((rc = read(fd, buf, sizeof(buf) - 1)) != -1) {
-
-		if (rc == 0)
-			continue;
-		if (buf[rc - 1] == '\n')
-			buf[--rc] = '\0';
-		else
-			buf[rc] = '\0';
-
-		DBG(CXT, ul_debug("message from kernel: \"%*s\"", rc, buf));
-		mnt_context_append_mesg(cxt, (char *) buf);
-	}
-}
-
 static void hookset_set_syscall_status(struct libmnt_context *cxt,
 				       const char *name, int x)
 {
@@ -93,7 +74,7 @@ static void hookset_set_syscall_status(struct libmnt_context *cxt,
 
 	api = get_sysapi(cxt);
 	if (api && api->fd_fs >= 0)
-		save_fd_messages(cxt, api->fd_fs);
+		mnt_context_read_mesgs(cxt, api->fd_fs);
 }
 
 /*
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
index 47007d6c8..a4ce7c042 100644
--- a/libmount/src/mountP.h
+++ b/libmount/src/mountP.h
@@ -684,6 +684,7 @@ extern int mnt_context_mount_setopt(struct libmnt_context *cxt, int c, char *arg
 extern void mnt_context_reset_mesgs(struct libmnt_context *cxt);
 extern int mnt_context_append_mesg(struct libmnt_context *cxt, const char *msg);
 extern int mnt_context_sprintf_mesg(struct libmnt_context *cxt, const char *msg, ...);
+extern int mnt_context_read_mesgs(struct libmnt_context *cxt, int fd);
 
 extern int mnt_context_propagation_only(struct libmnt_context *cxt)
 			__attribute__((nonnull));