Introduce callback for logging

Introduce an API for custom log handler functions.  This allows libfuse
applications to send messages to syslog(3) or other logging systems.
See include/fuse_log.h for details.

Convert libfuse from fprintf(stderr, ...) to log_fuse(level, ...).  Most
messages are error messages with FUSE_LOG_ERR log level.  There are also
some debug messages which now use the FUSE_LOG_DEBUG log level.

Note that lib/mount_util.c is used by both libfuse and fusermount3.
Since fusermount3 does not link against libfuse, we cannot call
fuse_log() from lib/mount_util.c.  This file will continue to use
fprintf(stderr, ...) until someone figures out how to split it up.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 10 insertions, 10 deletions

diff --git a/lib/mount.c b/lib/mount.c
index 7a18c11..979f8d9 100644
--- a/lib/mount.c
+++ b/lib/mount.c
@@ -175,7 +175,7 @@ static void set_mount_flag(const char *s, int *flags)
 			return;
 		}
 	}
-	fprintf(stderr, "fuse: internal error, can't find mount flag\n");
+	fuse_log(FUSE_LOG_ERR, "fuse: internal error, can't find mount flag\n");
 	abort();
 }
 
@@ -248,7 +248,7 @@ static int receive_fd(int fd)
 
 	cmsg = CMSG_FIRSTHDR(&msg);
 	if (cmsg->cmsg_type != SCM_RIGHTS) {
-		fprintf(stderr, "got control message of unknown type %d\n",
+		fuse_log(FUSE_LOG_ERR, "got control message of unknown type %d\n",
 			cmsg->cmsg_type);
 		return -1;
 	}
@@ -312,7 +312,7 @@ static int fuse_mount_fusermount(const char *mountpoint, struct mount_opts *mo,
 	int rv;
 
 	if (!mountpoint) {
-		fprintf(stderr, "fuse: missing mountpoint parameter\n");
+		fuse_log(FUSE_LOG_ERR, "fuse: missing mountpoint parameter\n");
 		return -1;
 	}
 
@@ -393,13 +393,13 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
 	int res;
 
 	if (!mnt) {
-		fprintf(stderr, "fuse: missing mountpoint parameter\n");
+		fuse_log(FUSE_LOG_ERR, "fuse: missing mountpoint parameter\n");
 		return -1;
 	}
 
 	res = stat(mnt, &stbuf);
 	if (res == -1) {
-		fprintf(stderr ,"fuse: failed to access mountpoint %s: %s\n",
+		fuse_log(FUSE_LOG_ERR, "fuse: failed to access mountpoint %s: %s\n",
 			mnt, strerror(errno));
 		return -1;
 	}
@@ -413,9 +413,9 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
 	fd = open(devname, O_RDWR | O_CLOEXEC);
 	if (fd == -1) {
 		if (errno == ENODEV || errno == ENOENT)
-			fprintf(stderr, "fuse: device not found, try 'modprobe fuse' first\n");
+			fuse_log(FUSE_LOG_ERR, "fuse: device not found, try 'modprobe fuse' first\n");
 		else
-			fprintf(stderr, "fuse: failed to open %s: %s\n",
+			fuse_log(FUSE_LOG_ERR, "fuse: failed to open %s: %s\n",
 				devname, strerror(errno));
 		return -1;
 	}
@@ -435,7 +435,7 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
 
 	type = malloc((mo->subtype ? strlen(mo->subtype) : 0) + 32);
 	if (!type || !source) {
-		fprintf(stderr, "fuse: failed to allocate memory\n");
+		fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate memory\n");
 		goto out_close;
 	}
 
@@ -471,10 +471,10 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
 			int errno_save = errno;
 			if (mo->blkdev && errno == ENODEV &&
 			    !fuse_mnt_check_fuseblk())
-				fprintf(stderr,
+				fuse_log(FUSE_LOG_ERR,
 					"fuse: 'fuseblk' support missing\n");
 			else
-				fprintf(stderr, "fuse: mount failed: %s\n",
+				fuse_log(FUSE_LOG_ERR, "fuse: mount failed: %s\n",
 					strerror(errno_save));
 		}