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-rw-r--r--fuse/fuse_kern_chan.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/fuse/fuse_kern_chan.c b/fuse/fuse_kern_chan.c
new file mode 100644
index 000000000..4a9beb8f8
--- /dev/null
+++ b/fuse/fuse_kern_chan.c
@@ -0,0 +1,98 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU LGPLv2.
+ See the file COPYING.LIB
+*/
+
+#include "fuse_lowlevel.h"
+#include "fuse_kernel.h"
+#include "fuse_i.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <assert.h>
+
+static int fuse_kern_chan_receive(struct fuse_chan **chp, char *buf,
+ size_t size)
+{
+ struct fuse_chan *ch = *chp;
+ int err;
+ ssize_t res;
+ struct fuse_session *se = fuse_chan_session(ch);
+ assert(se != NULL);
+
+restart:
+ res = read(fuse_chan_fd(ch), buf, size);
+ err = errno;
+
+ if (fuse_session_exited(se))
+ return 0;
+ if (res == -1) {
+ /* ENOENT means the operation was interrupted, it's safe
+ to restart */
+ if (err == ENOENT)
+ goto restart;
+
+ if (err == ENODEV) {
+ fuse_session_exit(se);
+ return 0;
+ }
+ /* Errors occurring during normal operation: EINTR (read
+ interrupted), EAGAIN (nonblocking I/O), ENODEV (filesystem
+ umounted) */
+ if (err != EINTR && err != EAGAIN)
+ perror("fuse: reading device");
+ return -err;
+ }
+ if ((size_t) res < sizeof(struct fuse_in_header)) {
+ fprintf(stderr, "short read on fuse device\n");
+ return -EIO;
+ }
+ return res;
+}
+
+static int fuse_kern_chan_send(struct fuse_chan *ch, const struct iovec iov[],
+ size_t count)
+{
+ if (iov) {
+ ssize_t res = writev(fuse_chan_fd(ch), iov, count);
+ int err = errno;
+
+ if (res == -1) {
+ struct fuse_session *se = fuse_chan_session(ch);
+
+ assert(se != NULL);
+
+ /* ENOENT means the operation was interrupted */
+ if (!fuse_session_exited(se) && err != ENOENT)
+ perror("fuse: writing device");
+ return -err;
+ }
+ }
+ return 0;
+}
+
+static void fuse_kern_chan_destroy(struct fuse_chan *ch)
+{
+ int fd = fuse_chan_fd(ch);
+
+ if (fd != -1)
+ close(fd);
+}
+
+#define MIN_BUFSIZE 0x21000
+
+struct fuse_chan *fuse_kern_chan_new(int fd)
+{
+ struct fuse_chan_ops op = {
+ .receive = fuse_kern_chan_receive,
+ .send = fuse_kern_chan_send,
+ .destroy = fuse_kern_chan_destroy,
+ };
+ size_t bufsize = getpagesize() + 0x1000;
+ bufsize = bufsize < MIN_BUFSIZE ? MIN_BUFSIZE : bufsize;
+ return fuse_chan_new(&op, fd, bufsize, NULL);
+}