writing modules made more easy
diff --git a/BUGS b/BUGS
index cd56648..0c1fb6c 100644
--- a/BUGS
+++ b/BUGS
@@ -5,3 +5,7 @@
- I want really low priority for my cached pages. Can they start out
'old' so they will be thrown out on the first oportunity?
+
+- File size change could cause some strange behavior WRT the page
+ cache.
+
diff --git a/example/.cvsignore b/example/.cvsignore
index 94a32e3..e4188bc 100644
--- a/example/.cvsignore
+++ b/example/.cvsignore
@@ -3,3 +3,4 @@
.deps
fusexmp
null
+hello
diff --git a/example/Makefile.am b/example/Makefile.am
index 19a3c32..a3880fa 100644
--- a/example/Makefile.am
+++ b/example/Makefile.am
@@ -1,8 +1,9 @@
## Process this file with automake to produce Makefile.in
-noinst_PROGRAMS = fusexmp null
+noinst_PROGRAMS = fusexmp null hello
fusexmp_SOURCES = fusexmp.c
null_SOURCES = null.c
+hello_SOURCES = hello.c
LDADD = ../lib/libfuse.a -lpthread
diff --git a/example/fusexmp.c b/example/fusexmp.c
index dc2a569..b9df79c 100644
--- a/example/fusexmp.c
+++ b/example/fusexmp.c
@@ -11,18 +11,12 @@
#define _XOPEN_SOURCE 500
#endif
-/* For setgroups() */
-#define _BSD_SOURCE
-
#include <fuse.h>
#include <stdio.h>
-#include <stdlib.h>
#include <unistd.h>
+#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
-#include <signal.h>
-#include <utime.h>
-#include <fcntl.h>
static int xmp_getattr(const char *path, struct stat *stbuf)
{
@@ -237,7 +231,6 @@
return res;
}
-
static struct fuse_operations xmp_oper = {
getattr: xmp_getattr,
readlink: xmp_readlink,
@@ -258,93 +251,8 @@
write: xmp_write,
};
-static void cleanup()
-{
- close(0);
- system(getenv("FUSE_UNMOUNT_CMD"));
-}
-
-static void exit_handler()
-{
- exit(0);
-}
-
-static void set_signal_handlers()
-{
- struct sigaction sa;
-
- sa.sa_handler = exit_handler;
- sigemptyset(&(sa.sa_mask));
- sa.sa_flags = 0;
-
- if (sigaction(SIGHUP, &sa, NULL) == -1 ||
- sigaction(SIGINT, &sa, NULL) == -1 ||
- sigaction(SIGTERM, &sa, NULL) == -1) {
-
- perror("Cannot set exit signal handlers");
- exit(1);
- }
-
- sa.sa_handler = SIG_IGN;
-
- if(sigaction(SIGPIPE, &sa, NULL) == -1) {
- perror("Cannot set ignored signals");
- exit(1);
- }
-}
-
int main(int argc, char *argv[])
{
- int argctr;
- int flags;
- int multithreaded;
- struct fuse *fuse;
-
- argctr = 1;
-
- atexit(cleanup);
- set_signal_handlers();
-
- flags = 0;
- multithreaded = 1;
- for(; argctr < argc && argv[argctr][0] == '-'; argctr ++) {
- switch(argv[argctr][1]) {
- case 'd':
- flags |= FUSE_DEBUG;
- break;
-
- case 's':
- multithreaded = 0;
- break;
-
- case 'h':
- fprintf(stderr,
- "usage: %s [options] \n"
- "Options:\n"
- " -d enable debug output\n"
- " -s disable multithreaded operation\n"
- " -h print help\n",
- argv[0]);
- exit(1);
- break;
-
- default:
- fprintf(stderr, "invalid option: %s\n", argv[argctr]);
- exit(1);
- }
- }
- if(argctr != argc) {
- fprintf(stderr, "missing or surplus argument\n");
- exit(1);
- }
-
- fuse = fuse_new(0, flags);
- fuse_set_operations(fuse, &xmp_oper);
-
- if(multithreaded)
- fuse_loop_mt(fuse);
- else
- fuse_loop(fuse);
-
+ fuse_main(argc, argv, &xmp_oper);
return 0;
}
diff --git a/example/hello.c b/example/hello.c
new file mode 100644
index 0000000..5cf75f4
--- /dev/null
+++ b/example/hello.c
@@ -0,0 +1,92 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include <fuse.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+
+static const char *hello_str = "Hello World!\n";
+
+static int hello_getattr(const char *path, struct stat *stbuf)
+{
+ int res = 0;
+
+ memset(stbuf, 0, sizeof(struct stat));
+ if(strcmp(path, "/") == 0) {
+ stbuf->st_mode = S_IFDIR | 0755;
+ stbuf->st_nlink = 2;
+ }
+ else if(strcmp(path, "/hello") == 0) {
+ stbuf->st_mode = S_IFREG | 0644;
+ stbuf->st_nlink = 1;
+ stbuf->st_size = strlen(hello_str);
+ }
+ else
+ res = -ENOENT;
+
+ return res;
+}
+
+static int hello_getdir(const char *path, fuse_dirh_t h, fuse_dirfil_t filler)
+{
+ if(strcmp(path, "/") != 0)
+ return -ENOENT;
+
+ filler(h, ".", 0);
+ filler(h, "..", 0);
+ filler(h, "hello", 0);
+
+ return 0;
+}
+
+static int hello_open(const char *path, int flags)
+{
+ if(strcmp(path, "/hello") != 0)
+ return -ENOENT;
+
+ if((flags & 3) != O_RDONLY)
+ return -EACCES;
+
+ return 0;
+}
+
+static int hello_read(const char *path, char *buf, size_t size, off_t offset)
+{
+ if(strcmp(path, "/hello") != 0)
+ return -ENOENT;
+
+ memcpy(buf, hello_str + offset, size);
+ return size;
+}
+
+static struct fuse_operations null_oper = {
+ getattr: hello_getattr,
+ readlink: NULL,
+ getdir: hello_getdir,
+ mknod: NULL,
+ mkdir: NULL,
+ symlink: NULL,
+ unlink: NULL,
+ rmdir: NULL,
+ rename: NULL,
+ link: NULL,
+ chmod: NULL,
+ chown: NULL,
+ truncate: NULL,
+ utime: NULL,
+ open: hello_open,
+ read: hello_read,
+ write: NULL,
+};
+
+int main(int argc, char *argv[])
+{
+ fuse_main(argc, argv, &null_oper);
+ return 0;
+}
diff --git a/example/null.c b/example/null.c
index c9816f1..7be4ab4 100644
--- a/example/null.c
+++ b/example/null.c
@@ -7,13 +7,10 @@
*/
#include <fuse.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
+
#include <unistd.h>
-#include <signal.h>
#include <time.h>
+#include <errno.h>
#define UNUSED __attribute__((unused))
@@ -88,93 +85,8 @@
write: null_write,
};
-static void cleanup()
-{
- close(0);
- system(getenv("FUSE_UNMOUNT_CMD"));
-}
-
-static void exit_handler()
-{
- exit(0);
-}
-
-static void set_signal_handlers()
-{
- struct sigaction sa;
-
- sa.sa_handler = exit_handler;
- sigemptyset(&(sa.sa_mask));
- sa.sa_flags = 0;
-
- if (sigaction(SIGHUP, &sa, NULL) == -1 ||
- sigaction(SIGINT, &sa, NULL) == -1 ||
- sigaction(SIGTERM, &sa, NULL) == -1) {
-
- perror("Cannot set exit signal handlers");
- exit(1);
- }
-
- sa.sa_handler = SIG_IGN;
-
- if(sigaction(SIGPIPE, &sa, NULL) == -1) {
- perror("Cannot set ignored signals");
- exit(1);
- }
-}
-
int main(int argc, char *argv[])
{
- int argctr;
- int flags;
- int multithreaded;
- struct fuse *fuse;
-
- argctr = 1;
-
- atexit(cleanup);
- set_signal_handlers();
-
- flags = 0;
- multithreaded = 1;
- for(; argctr < argc && argv[argctr][0] == '-'; argctr ++) {
- switch(argv[argctr][1]) {
- case 'd':
- flags |= FUSE_DEBUG;
- break;
-
- case 's':
- multithreaded = 0;
- break;
-
- case 'h':
- fprintf(stderr,
- "usage: %s [options] \n"
- "Options:\n"
- " -d enable debug output\n"
- " -s disable multithreaded operation\n"
- " -h print help\n",
- argv[0]);
- exit(1);
- break;
-
- default:
- fprintf(stderr, "invalid option: %s\n", argv[argctr]);
- exit(1);
- }
- }
- if(argctr != argc) {
- fprintf(stderr, "missing or surplus argument\n");
- exit(1);
- }
-
- fuse = fuse_new(0, flags);
- fuse_set_operations(fuse, &null_oper);
-
- if(multithreaded)
- fuse_loop_mt(fuse);
- else
- fuse_loop(fuse);
-
+ fuse_main(argc, argv, &null_oper);
return 0;
}
diff --git a/include/fuse.h b/include/fuse.h
index abdb45b..42ef8bb 100644
--- a/include/fuse.h
+++ b/include/fuse.h
@@ -12,6 +12,10 @@
#include <sys/stat.h>
#include <utime.h>
+/* ----------------------------------------------------------- *
+ * Basic FUSE API *
+ * ----------------------------------------------------------- */
+
/** Handle for a FUSE filesystem */
struct fuse;
@@ -81,6 +85,7 @@
/** Enable debuging output */
#define FUSE_DEBUG (1 << 1)
+
/**
* Create a new FUSE filesystem.
*
@@ -108,6 +113,7 @@
* operations are called.
*
* @param f the FUSE handle
+ * @prarm op the file system operations
*/
void fuse_loop(struct fuse *f);
@@ -134,6 +140,30 @@
*/
void fuse_destroy(struct fuse *f);
+/* ----------------------------------------------------------- *
+ * Miscellaneous helper fuctions *
+ * ----------------------------------------------------------- */
+
+/*
+ * Main function of FUSE.
+ *
+ * This is for the lazy. This is all that has to be called from the
+ * main() function.
+ *
+ * This function does the following:
+ * - mounts the filesystem
+ * - installs signal handlers for INT, HUP, TERM and PIPE
+ * - registers an exit handler to unmount the filesystem on program exit
+ * - parses command line options (-d -s and -h)
+ * - creates a fuse handle
+ * - registers the operations
+ * - calls either the single-threaded or the multi-threaded event loop
+ *
+ * @param argc the argument counter passed to the main() function
+ * @param argv the argument vector passed to the main() function
+ * @prarm op the file system operation
+ */
+void fuse_main(int argc, char *argv[], const struct fuse_operations *op);
/* ----------------------------------------------------------- *
* Advanced API for event handling, don't worry about this... *
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 7f289f7..5ecee0b 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -5,4 +5,5 @@
libfuse_a_SOURCES = \
fuse.c \
fuse_mt.c \
+ helper.c \
fuse_i.h
diff --git a/lib/fuse.c b/lib/fuse.c
index 4042993..c8bc3e4 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -17,6 +17,8 @@
#define FUSE_MAX_PATH 4096
+#define FUSE_KERNEL_VERSION_ENV "_FUSE_KERNEL_VERSION"
+
static struct node *__get_node(struct fuse *f, fino_t ino)
{
size_t hash = ino % f->ino_table_size;
@@ -891,7 +893,7 @@
struct fuse *f;
struct node *root;
char verstr[128];
- char *realver = getenv("FUSE_KERNEL_VERSION");
+ char *realver = getenv(FUSE_KERNEL_VERSION_ENV);
if(realver != NULL) {
sprintf(verstr, "%i", FUSE_KERNEL_VERSION);
diff --git a/lib/helper.c b/lib/helper.c
new file mode 100644
index 0000000..f4a8a16
--- /dev/null
+++ b/lib/helper.c
@@ -0,0 +1,154 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#include <signal.h>
+#include <errno.h>
+
+#define FUSE_MOUNTED_ENV "_FUSE_MOUNTED"
+#define FUSE_UMOUNT_CMD_ENV "_FUSE_UNMOUNT_CMD"
+
+static void usage(char *progname)
+{
+ fprintf(stderr,
+ "usage: %s mountpoint [options] \n"
+ "Options:\n"
+ " -d enable debug output\n"
+ " -s disable multithreaded operation\n"
+ " -h print help\n",
+ progname);
+ exit(1);
+}
+
+static void fuse_unmount()
+{
+ close(0);
+ system(getenv(FUSE_UMOUNT_CMD_ENV));
+}
+
+static int fuse_mount(int *argcp, char **argv)
+{
+ char *isreexec = getenv(FUSE_MOUNTED_ENV);
+
+ if(isreexec == NULL) {
+ int i;
+ int argc = *argcp;
+ char *mountprog = "fusermount";
+ char **newargv = (char **) malloc((1 + argc + 1) * sizeof(char *));
+
+ if(argc < 2 || argv[1][0] == '-')
+ usage(argv[0]);
+
+ /* oldargs: "PROG MOUNTPOINT ARGS..."
+ newargs: "fusermount MOUNTPOINT PROG ARGS..." */
+
+ newargv[0] = mountprog;
+ newargv[1] = argv[1];
+ newargv[2] = argv[0];
+ for(i = 2; i < argc; i++)
+ newargv[i+1] = argv[i];
+ newargv[i+1] = NULL;
+
+ execvp(mountprog, newargv);
+ fprintf(stderr, "fuse: failed to exec %s: %s\n", mountprog,
+ strerror(errno));
+ return -1;
+ }
+ unsetenv(FUSE_MOUNTED_ENV);
+
+ /* The actual file descriptor is stdin */
+ return 0;
+}
+
+
+static void exit_handler()
+{
+ exit(0);
+}
+
+static void set_signal_handlers()
+{
+ struct sigaction sa;
+
+ sa.sa_handler = exit_handler;
+ sigemptyset(&(sa.sa_mask));
+ sa.sa_flags = 0;
+
+ if (sigaction(SIGHUP, &sa, NULL) == -1 ||
+ sigaction(SIGINT, &sa, NULL) == -1 ||
+ sigaction(SIGTERM, &sa, NULL) == -1) {
+
+ perror("Cannot set exit signal handlers");
+ exit(1);
+ }
+
+ sa.sa_handler = SIG_IGN;
+
+ if(sigaction(SIGPIPE, &sa, NULL) == -1) {
+ perror("Cannot set ignored signals");
+ exit(1);
+ }
+}
+
+void fuse_main(int argc, char *argv[], const struct fuse_operations *op)
+{
+ int fd;
+ int argctr;
+ int flags;
+ int multithreaded;
+ struct fuse *fuse;
+
+ fd = fuse_mount(&argc, argv);
+ if(fd == -1)
+ exit(1);
+
+ atexit(fuse_unmount);
+ set_signal_handlers();
+
+ argctr = 1;
+ flags = 0;
+ multithreaded = 1;
+ for(; argctr < argc && argv[argctr][0] == '-'; argctr ++) {
+ switch(argv[argctr][1]) {
+ case 'd':
+ flags |= FUSE_DEBUG;
+ break;
+
+ case 's':
+ multithreaded = 0;
+ break;
+
+ case 'h':
+ usage(argv[0]);
+ break;
+
+ default:
+ fprintf(stderr, "invalid option: %s\n", argv[argctr]);
+ exit(1);
+ }
+ }
+ if(argctr != argc) {
+ fprintf(stderr, "missing or surplus argument\n");
+ exit(1);
+ }
+
+ fuse = fuse_new(fd, flags);
+ fuse_set_operations(fuse, op);
+
+ if(multithreaded)
+ fuse_loop_mt(fuse);
+ else
+ fuse_loop(fuse);
+}
+
diff --git a/util/fusermount.c b/util/fusermount.c
index 0e256e5..ee51269 100644
--- a/util/fusermount.c
+++ b/util/fusermount.c
@@ -39,6 +39,10 @@
#define FUSE_DEV "/proc/fs/fuse/dev"
+#define FUSE_MOUNTED_ENV "_FUSE_MOUNTED"
+#define FUSE_UMOUNT_CMD_ENV "_FUSE_UNMOUNT_CMD"
+#define FUSE_KERNEL_VERSION_ENV "_FUSE_KERNEL_VERSION"
+
const char *progname;
static const char *get_user_name()
@@ -497,9 +501,10 @@
unmount_cmd = (char *) malloc(strlen(mypath) + strlen(mnt) + 64);
sprintf(unmount_cmd, "%s -u %s", mypath, mnt);
- setenv("FUSE_UNMOUNT_CMD", unmount_cmd, 1);
+ setenv(FUSE_UMOUNT_CMD_ENV, unmount_cmd, 1);
sprintf(verstr, "%i", FUSE_KERNEL_VERSION);
- setenv("FUSE_KERNEL_VERSION", verstr, 1);
+ setenv(FUSE_KERNEL_VERSION_ENV, verstr, 1);
+ setenv(FUSE_MOUNTED_ENV, "", 1);
execvp(userprog[0], userprog);
fprintf(stderr, "%s: failed to exec %s: %s\n", progname, userprog[0],