for unknown reasons -- maybe because it tries to treat the
mountpoint as a file rather than a directory?
-* There is a new ``timefs3`` example that demonstrates the use of
- `fuse_lowlevel_notify_inval_entry`.
+* There are several new examples that demonstrate the use of
+ the ``fuse_lowlevel_notify_*`` functions:
-* There are new ``timefs1`` and ``timefs2`` examples that demonstrate
- the use of the `fuse_lowlevel_notify_store`,
- `fuse_lowlevel_notify_retrieve`, and
- `fuse_lowlevel_notify_inval_inode` functions.
+ - ``example/notify_store_retrieve.c``
+ - ``example/notify_inval_inode.c``
+ - ``example/notify_inval_entry.c``
* The ``-o big_writes`` mount option has been removed. It is now
always active. File systems that want to limit the size of write
/poll_client
/cusexmp
/passthrough_ll
-/timefs1
-/timefs2
+/notify_inval_inode
+/notify_store_retrieve
+/notify_inval_entry
noinst_HEADERS = ioctl.h
noinst_PROGRAMS = passthrough passthrough_fh hello hello_ll \
ioctl ioctl_client poll poll_client \
- cusexmp passthrough_ll timefs1 timefs2 \
- timefs3
+ cusexmp passthrough_ll notify_inval_inode \
+ notify_store_retrieve notify_inval_entry
LDADD = ../lib/libfuse3.la
passthrough_fh_LDADD = ../lib/libfuse3.la @passthrough_fh_libs@
--- /dev/null
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/** @file
+ * @tableofcontents
+ *
+ * This example implements a file system with a single file whose
+ * file name changes dynamically to reflect the current time.
+ *
+ * It illustrates the use of the fuse_lowlevel_notify_inval_entry()
+ * function.
+ *
+ * To see the effect, first start the file system with the
+ * ``--no-notify``
+ *
+ * $ notify_inval_entry --update-interval=1 --timeout 30 --no-notify mnt/
+ *
+ * Observe that `ls` always prints the correct directory contents
+ * (since `readdir` output is not cached)::
+ *
+ * $ ls mnt; sleep 1; ls mnt; sleep 1; ls mnt
+ * Time_is_15h_48m_33s current_time
+ * Time_is_15h_48m_34s current_time
+ * Time_is_15h_48m_35s current_time
+ *
+ * However, if you try to access a file by name the kernel will
+ * report that it still exists:
+ *
+ * $ file=$(ls mnt/); echo $file
+ * Time_is_15h_50m_09s
+ * $ sleep 5; stat mnt/$file
+ * File: ‘mnt/Time_is_15h_50m_09s’
+ * Size: 32 Blocks: 0 IO Block: 4096 regular file
+ * Device: 2ah/42d Inode: 3 Links: 1
+ * Access: (0444/-r--r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
+ * Access: 1969-12-31 16:00:00.000000000 -0800
+ * Modify: 1969-12-31 16:00:00.000000000 -0800
+ * Change: 1969-12-31 16:00:00.000000000 -0800
+ * Birth: -
+ *
+ * Only once the kernel cache timeout has been reached will the stat
+ * call fail:
+ *
+ * $ sleep 30; stat mnt/$file
+ * stat: cannot stat ‘mnt/Time_is_15h_50m_09s’: No such file or directory
+ *
+ * In contrast, if you enable notifications you will be unable to stat
+ * the file as soon as the file system updates its name:
+ *
+ * $ notify_inval_entry --update-interval=1 --timeout 30 --no-notify mnt/
+ * $ file=$(ls mnt/); stat mnt/$file
+ * File: ‘mnt/Time_is_20h_42m_11s’
+ * Size: 0 Blocks: 0 IO Block: 4096 regular empty file
+ * Device: 2ah/42d Inode: 2 Links: 1
+ * Access: (0000/----------) Uid: ( 0/ root) Gid: ( 0/ root)
+ * Access: 1969-12-31 16:00:00.000000000 -0800
+ * Modify: 1969-12-31 16:00:00.000000000 -0800
+ * Change: 1969-12-31 16:00:00.000000000 -0800
+ * Birth: -
+ * $ sleep 1; stat mnt/$file
+ * stat: cannot stat ‘mnt/Time_is_20h_42m_11s’: No such file or directory
+ *
+ * \section section_compile compiling this example
+ *
+ * gcc -Wall notify_inval_entry.c `pkg-config fuse3 --cflags --libs` -o notify_inval_entry
+ *
+ * \section section_source the complete source
+ * \include notify_inval_entry.c
+ */
+
+
+#define FUSE_USE_VERSION 30
+
+#include <config.h>
+
+#include <fuse_lowlevel.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#define MAX_STR_LEN 128
+static char file_name[MAX_STR_LEN];
+static fuse_ino_t file_ino = 2;
+static int lookup_cnt = 0;
+
+/* Command line parsing */
+struct options {
+ int no_notify;
+ float timeout;
+ int update_interval;
+};
+static struct options options = {
+ .timeout = 5,
+ .no_notify = 0,
+ .update_interval = 1,
+};
+
+#define OPTION(t, p) \
+ { t, offsetof(struct options, p), 1 }
+static const struct fuse_opt option_spec[] = {
+ OPTION("--no-notify", no_notify),
+ OPTION("--update-interval=%d", update_interval),
+ OPTION("--timeout=%f", timeout),
+ FUSE_OPT_END
+};
+
+static int opt_proc(void *data, const char *arg, int key,
+ struct fuse_args *outargs) {
+ (void) outargs; (void) data; (void) arg;
+ (void) key;
+ return 1;
+}
+
+static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
+ stbuf->st_ino = ino;
+ if (ino == FUSE_ROOT_ID) {
+ stbuf->st_mode = S_IFDIR | 0755;
+ stbuf->st_nlink = 1;
+ }
+
+ else if (ino == file_ino) {
+ stbuf->st_mode = S_IFREG | 0000;
+ stbuf->st_nlink = 1;
+ stbuf->st_size = 0;
+ }
+
+ else
+ return -1;
+
+ return 0;
+}
+
+static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
+ const char *name) {
+ struct fuse_entry_param e;
+ memset(&e, 0, sizeof(e));
+
+ if (parent != FUSE_ROOT_ID)
+ goto err_out;
+ else if (strcmp(name, file_name) == 0) {
+ e.ino = file_ino;
+ lookup_cnt++;
+ } else
+ goto err_out;
+
+ e.attr_timeout = options.timeout;
+ e.entry_timeout = options.timeout;
+ if (tfs_stat(e.ino, &e.attr) != 0)
+ goto err_out;
+ fuse_reply_entry(req, &e);
+ return;
+
+err_out:
+ fuse_reply_err(req, ENOENT);
+}
+
+static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
+ uint64_t nlookup) {
+ (void) req;
+ assert(ino == file_ino || ino == FUSE_ROOT_ID);
+ lookup_cnt -= nlookup;
+ fuse_reply_none(req);
+}
+
+
+static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi) {
+ struct stat stbuf;
+
+ (void) fi;
+
+ memset(&stbuf, 0, sizeof(stbuf));
+ if (tfs_stat(ino, &stbuf) != 0)
+ fuse_reply_err(req, ENOENT);
+ else
+ fuse_reply_attr(req, &stbuf, options.timeout);
+}
+
+struct dirbuf {
+ char *p;
+ size_t size;
+};
+
+static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
+ fuse_ino_t ino) {
+ struct stat stbuf;
+ size_t oldsize = b->size;
+ b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
+ b->p = (char *) realloc(b->p, b->size);
+ memset(&stbuf, 0, sizeof(stbuf));
+ stbuf.st_ino = ino;
+ fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
+ b->size);
+}
+
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
+ off_t off, size_t maxsize) {
+ if (off < bufsize)
+ return fuse_reply_buf(req, buf + off,
+ min(bufsize - off, maxsize));
+ else
+ return fuse_reply_buf(req, NULL, 0);
+}
+
+static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
+ off_t off, struct fuse_file_info *fi) {
+ (void) fi;
+
+ if (ino != FUSE_ROOT_ID)
+ fuse_reply_err(req, ENOTDIR);
+ else {
+ struct dirbuf b;
+
+ memset(&b, 0, sizeof(b));
+ dirbuf_add(req, &b, file_name, file_ino);
+ reply_buf_limited(req, b.p, b.size, off, size);
+ free(b.p);
+ }
+}
+
+static struct fuse_lowlevel_ops tfs_oper = {
+ .lookup = tfs_lookup,
+ .getattr = tfs_getattr,
+ .readdir = tfs_readdir,
+ .forget = tfs_forget,
+};
+
+static void* update_fs(void *data) {
+ struct fuse_session *se = (struct fuse_session*) data;
+ struct tm *now;
+ char *old_name;
+ time_t t;
+ ssize_t ret;
+
+ while(1) {
+ t = time(NULL);
+ now = localtime(&t);
+ assert(now != NULL);
+
+ old_name = strdup(file_name);
+ ret = strftime(file_name, MAX_STR_LEN,
+ "Time_is_%Hh_%Mm_%Ss", now);
+ assert(ret != 0);
+
+ if (!options.no_notify && lookup_cnt)
+ assert(fuse_lowlevel_notify_inval_entry
+ (se, FUSE_ROOT_ID, old_name, strlen(old_name)) == 0);
+ free(old_name);
+ sleep(options.update_interval);
+ }
+ return NULL;
+}
+
+static void show_help(const char *progname)
+{
+ printf("usage: %s [options] <mountpoint>\n\n", progname);
+ printf("File-system specific options:\n"
+ " --timeout=<secs> Timeout for kernel caches\n"
+ " --update-interval=<secs> Update-rate of file system contents\n"
+ " --no-notify Disable kernel notifications\n"
+ "\n");
+}
+
+int main(int argc, char *argv[]) {
+ struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
+ struct fuse_session *se;
+ struct fuse_cmdline_opts opts;
+ pthread_t updater;
+ int ret = -1;
+
+ if (fuse_opt_parse(&args, &options, option_spec,
+ opt_proc) == -1)
+ return 1;
+
+ if (fuse_parse_cmdline(&args, &opts) != 0)
+ return 1;
+ if (opts.show_help) {
+ show_help(argv[0]);
+ fuse_cmdline_help();
+ fuse_lowlevel_help();
+ fuse_mount_help();
+ ret = 0;
+ goto err_out1;
+ } else if (opts.show_version) {
+ printf("FUSE library version %s\n", fuse_pkgversion());
+ fuse_lowlevel_version();
+ fuse_mount_version();
+ ret = 0;
+ goto err_out1;
+ }
+
+ se = fuse_session_new(&args, &tfs_oper,
+ sizeof(tfs_oper), NULL);
+ if (se == NULL)
+ goto err_out1;
+
+ if (fuse_set_signal_handlers(se) != 0)
+ goto err_out2;
+
+ if (fuse_session_mount(se, opts.mountpoint) != 0)
+ goto err_out3;
+
+ fuse_daemonize(opts.foreground);
+
+ /* Start thread to update file contents */
+ ret = pthread_create(&updater, NULL, update_fs, (void *)se);
+ if (ret != 0) {
+ fprintf(stderr, "pthread_create failed with %s\n",
+ strerror(ret));
+ goto err_out3;
+ }
+
+ /* Block until ctrl+c or fusermount -u */
+ if (opts.singlethread)
+ ret = fuse_session_loop(se);
+ else
+ ret = fuse_session_loop_mt(se);
+
+ fuse_session_unmount(se);
+err_out3:
+ fuse_remove_signal_handlers(se);
+err_out2:
+ fuse_session_destroy(se);
+err_out1:
+ free(opts.mountpoint);
+ fuse_opt_free_args(&args);
+
+ return ret ? 1 : 0;
+}
+
+
+/**
+ * Local Variables:
+ * mode: c
+ * indent-tabs-mode: nil
+ * c-basic-offset: 4
+ * End:
+ */
--- /dev/null
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/** @file
+ * @tableofcontents
+ *
+ * This example implements a file system with a single file whose
+ * contents change dynamically: it always contains the current time.
+ *
+ * While notify_store_retrieve.c uses fuse_lowlevel_notify_store() to
+ * actively push the updated data into the kernel cache, this example
+ * uses fuse_lowlevel_notify_inval_inode() to notify the kernel that
+ * the cache has to be invalidated - but the kernel still has to
+ * explicitly request the updated data on the next read.
+ *
+ * To see the effect, first start the file system with the
+ * ``--no-notify`` option:
+ *
+ * $ notify_inval_inode --update-interval=1 --no-notify mnt/
+ *
+ * Observe that the output never changes, even though the file system
+ * updates it once per second. This is because the contents are cached
+ * in the kernel:
+ *
+ * $ for i in 1 2 3 4 5; do
+ * > cat mnt/current_time
+ * > sleep 1
+ * > done
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ *
+ * If you instead enable the notification functions, the changes become
+ * visible:
+ *
+ * $ notify_inval_inode --update-interval=1 mnt/
+ * $ for i in 1 2 3 4 5; do
+ * > cat mnt/current_time
+ * > sleep 1
+ * > done
+ * The current time is 15:58:40
+ * The current time is 15:58:41
+ * The current time is 15:58:42
+ * The current time is 15:58:43
+ * The current time is 15:58:44
+ *
+ * \section section_compile compiling this example
+ *
+ * gcc -Wall notify_inval_inode.c `pkg-config fuse3 --cflags --libs` -o notify_inval_inode
+ *
+ * \section section_source the complete source
+ * \include notify_inval_inode.c
+ */
+
+
+#define FUSE_USE_VERSION 30
+
+#include <config.h>
+
+#include <fuse_lowlevel.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <pthread.h>
+
+/* We can't actually tell the kernel that there is no
+ timeout, so we just send a big value */
+#define NO_TIMEOUT 500000
+
+/* We cannot check directly if e.g. O_RDONLY is set, since this is not
+ * an individual bit (cf. open(2)) */
+#define ACCESS_MASK (O_RDONLY | O_WRONLY | O_RDWR)
+
+#define MAX_STR_LEN 128
+#define FILE_INO 2
+#define FILE_NAME "current_time"
+static char file_contents[MAX_STR_LEN];
+static int lookup_cnt = 0;
+static size_t file_size;
+
+/* Command line parsing */
+struct options {
+ int no_notify;
+ int update_interval;
+};
+static struct options options = {
+ .no_notify = 0,
+ .update_interval = 1,
+};
+
+#define OPTION(t, p) \
+ { t, offsetof(struct options, p), 1 }
+static const struct fuse_opt option_spec[] = {
+ OPTION("--no-notify", no_notify),
+ OPTION("--update-interval=%d", update_interval),
+ FUSE_OPT_END
+};
+
+static int opt_proc(void *data, const char *arg, int key,
+ struct fuse_args *outargs) {
+ (void) outargs; (void) data; (void) arg;
+ (void) key;
+ return 1;
+}
+
+static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
+ stbuf->st_ino = ino;
+ if (ino == FUSE_ROOT_ID) {
+ stbuf->st_mode = S_IFDIR | 0755;
+ stbuf->st_nlink = 1;
+ }
+
+ else if (ino == FILE_INO) {
+ stbuf->st_mode = S_IFREG | 0444;
+ stbuf->st_nlink = 1;
+ stbuf->st_size = file_size;
+ }
+
+ else
+ return -1;
+
+ return 0;
+}
+
+static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
+ const char *name) {
+ struct fuse_entry_param e;
+ memset(&e, 0, sizeof(e));
+
+ if (parent != FUSE_ROOT_ID)
+ goto err_out;
+ else if (strcmp(name, FILE_NAME) == 0) {
+ e.ino = FILE_INO;
+ lookup_cnt++;
+ } else
+ goto err_out;
+
+ e.attr_timeout = NO_TIMEOUT;
+ e.entry_timeout = NO_TIMEOUT;
+ if (tfs_stat(e.ino, &e.attr) != 0)
+ goto err_out;
+ fuse_reply_entry(req, &e);
+ return;
+
+err_out:
+ fuse_reply_err(req, ENOENT);
+}
+
+static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
+ uint64_t nlookup) {
+ (void) req;
+ assert(ino == FILE_INO || ino == FUSE_ROOT_ID);
+ lookup_cnt -= nlookup;
+ fuse_reply_none(req);
+}
+
+static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi) {
+ struct stat stbuf;
+
+ (void) fi;
+
+ memset(&stbuf, 0, sizeof(stbuf));
+ if (tfs_stat(ino, &stbuf) != 0)
+ fuse_reply_err(req, ENOENT);
+ else
+ fuse_reply_attr(req, &stbuf, NO_TIMEOUT);
+}
+
+struct dirbuf {
+ char *p;
+ size_t size;
+};
+
+static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
+ fuse_ino_t ino) {
+ struct stat stbuf;
+ size_t oldsize = b->size;
+ b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
+ b->p = (char *) realloc(b->p, b->size);
+ memset(&stbuf, 0, sizeof(stbuf));
+ stbuf.st_ino = ino;
+ fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
+ b->size);
+}
+
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
+ off_t off, size_t maxsize) {
+ if (off < bufsize)
+ return fuse_reply_buf(req, buf + off,
+ min(bufsize - off, maxsize));
+ else
+ return fuse_reply_buf(req, NULL, 0);
+}
+
+static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
+ off_t off, struct fuse_file_info *fi) {
+ (void) fi;
+
+ if (ino != FUSE_ROOT_ID)
+ fuse_reply_err(req, ENOTDIR);
+ else {
+ struct dirbuf b;
+
+ memset(&b, 0, sizeof(b));
+ dirbuf_add(req, &b, FILE_NAME, FILE_INO);
+ reply_buf_limited(req, b.p, b.size, off, size);
+ free(b.p);
+ }
+}
+
+static void tfs_open(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi) {
+
+ /* Make cache persistent even if file is closed,
+ this makes it easier to see the effects */
+ fi->keep_cache = 1;
+
+ if (ino == FUSE_ROOT_ID)
+ fuse_reply_err(req, EISDIR);
+ else if ((fi->flags & ACCESS_MASK) != O_RDONLY)
+ fuse_reply_err(req, EACCES);
+ else if (ino == FILE_INO)
+ fuse_reply_open(req, fi);
+ else {
+ // This should not happen
+ fprintf(stderr, "Got open for non-existing inode!\n");
+ fuse_reply_err(req, ENOENT);
+ }
+}
+
+static void tfs_read(fuse_req_t req, fuse_ino_t ino, size_t size,
+ off_t off, struct fuse_file_info *fi) {
+ (void) fi;
+
+ assert(ino == FILE_INO);
+ reply_buf_limited(req, file_contents, file_size, off, size);
+}
+
+static struct fuse_lowlevel_ops tfs_oper = {
+ .lookup = tfs_lookup,
+ .getattr = tfs_getattr,
+ .readdir = tfs_readdir,
+ .open = tfs_open,
+ .read = tfs_read,
+ .forget = tfs_forget,
+};
+
+static void* update_fs(void *data) {
+ struct fuse_session *se = (struct fuse_session*) data;
+ struct tm *now;
+ time_t t;
+
+ while(1) {
+ t = time(NULL);
+ now = localtime(&t);
+ assert(now != NULL);
+
+ file_size = strftime(file_contents, MAX_STR_LEN,
+ "The current time is %H:%M:%S\n", now);
+ assert(file_size != 0);
+ if (!options.no_notify && lookup_cnt) {
+ /* Only send notification if the kernel
+ is aware of the inode */
+ assert(fuse_lowlevel_notify_inval_inode
+ (se, FILE_INO, 0, 0) == 0);
+ }
+ sleep(options.update_interval);
+ }
+ return NULL;
+}
+
+static void show_help(const char *progname)
+{
+ printf("usage: %s [options] <mountpoint>\n\n", progname);
+ printf("File-system specific options:\n"
+ " --update-interval=<secs> Update-rate of file system contents\n"
+ " --no-notify Disable kernel notifications\n"
+ "\n");
+}
+
+int main(int argc, char *argv[]) {
+ struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
+ struct fuse_session *se;
+ struct fuse_cmdline_opts opts;
+ pthread_t updater;
+ int ret = -1;
+
+ if (fuse_opt_parse(&args, &options, option_spec,
+ opt_proc) == -1)
+ return 1;
+
+ if (fuse_parse_cmdline(&args, &opts) != 0) {
+ ret = 1;
+ goto err_out1;
+ }
+
+ if (opts.show_help) {
+ show_help(argv[0]);
+ fuse_cmdline_help();
+ fuse_lowlevel_help();
+ fuse_mount_help();
+ ret = 0;
+ goto err_out1;
+ } else if (opts.show_version) {
+ printf("FUSE library version %s\n", fuse_pkgversion());
+ fuse_lowlevel_version();
+ fuse_mount_version();
+ ret = 0;
+ goto err_out1;
+ }
+
+ se = fuse_session_new(&args, &tfs_oper,
+ sizeof(tfs_oper), NULL);
+ if (se == NULL)
+ goto err_out1;
+
+ if (fuse_set_signal_handlers(se) != 0)
+ goto err_out2;
+
+ if (fuse_session_mount(se, opts.mountpoint) != 0)
+ goto err_out3;
+
+ fuse_daemonize(opts.foreground);
+
+ /* Start thread to update file contents */
+ ret = pthread_create(&updater, NULL, update_fs, (void *)se);
+ if (ret != 0) {
+ fprintf(stderr, "pthread_create failed with %s\n",
+ strerror(ret));
+ goto err_out3;
+ }
+
+ /* Block until ctrl+c or fusermount -u */
+ if (opts.singlethread)
+ ret = fuse_session_loop(se);
+ else
+ ret = fuse_session_loop_mt(se);
+
+ fuse_session_unmount(se);
+err_out3:
+ fuse_remove_signal_handlers(se);
+err_out2:
+ fuse_session_destroy(se);
+err_out1:
+ fuse_opt_free_args(&args);
+ free(opts.mountpoint);
+
+ return ret ? 1 : 0;
+}
+
+
+/**
+ * Local Variables:
+ * mode: c
+ * indent-tabs-mode: nil
+ * c-basic-offset: 4
+ * End:
+ */
--- /dev/null
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/** @file
+ * @tableofcontents
+ *
+ * This example implements a file system with a single file whose
+ * contents change dynamically: it always contains the current time.
+ *
+ * While notify_inval_inode.c uses fuse_lowlevel_notify_inval_inode()
+ * to let the kernel know that it has to invalidate the cache, this
+ * example actively pushes the updated data into the kernel cache
+ * using fuse_lowlevel_notify_store().
+ *
+ * To see the effect, first start the file system with the
+ * ``--no-notify`` option:
+ *
+ * $ notify_store_retrieve --update-interval=1 --no-notify mnt/
+ *
+ * Observe that the output never changes, even though the file system
+ * updates it once per second. This is because the contents are cached
+ * in the kernel:
+ *
+ * $ for i in 1 2 3 4 5; do
+ * > cat mnt/current_time
+ * > sleep 1
+ * > done
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ * The current time is 15:58:18
+ *
+ * If you instead enable the notification functions, the changes become
+ * visible:
+ *
+ * $ notify_store_retrieve --update-interval=1 mnt/
+ * $ for i in 1 2 3 4 5; do
+ * > cat mnt/current_time
+ * > sleep 1
+ * > done
+ * The current time is 15:58:40
+ * The current time is 15:58:41
+ * The current time is 15:58:42
+ * The current time is 15:58:43
+ * The current time is 15:58:44
+ *
+ * \section section_compile compiling this example
+ *
+ * gcc -Wall notify_store_retrieve.c `pkg-config fuse3 --cflags --libs` -o notify_store_retrieve
+ *
+ * \section section_source the complete source
+ * \include notify_store_retrieve.c
+ */
+
+
+#define FUSE_USE_VERSION 30
+
+#include <config.h>
+
+#include <fuse_lowlevel.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <pthread.h>
+
+/* We can't actually tell the kernel that there is no
+ timeout, so we just send a big value */
+#define NO_TIMEOUT 500000
+
+/* We cannot check directly if e.g. O_RDONLY is set, since this is not
+ * an individual bit (cf. open(2)) */
+#define ACCESS_MASK (O_RDONLY | O_WRONLY | O_RDWR)
+
+#define MAX_STR_LEN 128
+#define FILE_INO 2
+#define FILE_NAME "current_time"
+static char file_contents[MAX_STR_LEN];
+static int lookup_cnt = 0;
+static size_t file_size;
+
+/* Keep track if we ever stored data (==1), and
+ received it back correctly (==2) */
+static int retrieve_status = 0;
+
+/* Command line parsing */
+struct options {
+ int no_notify;
+ int update_interval;
+};
+static struct options options = {
+ .no_notify = 0,
+ .update_interval = 1,
+};
+
+#define OPTION(t, p) \
+ { t, offsetof(struct options, p), 1 }
+static const struct fuse_opt option_spec[] = {
+ OPTION("--no-notify", no_notify),
+ OPTION("--update-interval=%d", update_interval),
+ FUSE_OPT_END
+};
+
+static int opt_proc(void *data, const char *arg, int key,
+ struct fuse_args *outargs) {
+ (void) outargs; (void) data; (void) arg;
+ (void) key;
+ return 1;
+}
+
+static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
+ stbuf->st_ino = ino;
+ if (ino == FUSE_ROOT_ID) {
+ stbuf->st_mode = S_IFDIR | 0755;
+ stbuf->st_nlink = 1;
+ }
+
+ else if (ino == FILE_INO) {
+ stbuf->st_mode = S_IFREG | 0444;
+ stbuf->st_nlink = 1;
+ stbuf->st_size = file_size;
+ }
+
+ else
+ return -1;
+
+ return 0;
+}
+
+static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
+ const char *name) {
+ struct fuse_entry_param e;
+ memset(&e, 0, sizeof(e));
+
+ if (parent != FUSE_ROOT_ID)
+ goto err_out;
+ else if (strcmp(name, FILE_NAME) == 0) {
+ e.ino = FILE_INO;
+ lookup_cnt++;
+ } else
+ goto err_out;
+
+ e.attr_timeout = NO_TIMEOUT;
+ e.entry_timeout = NO_TIMEOUT;
+ if (tfs_stat(e.ino, &e.attr) != 0)
+ goto err_out;
+ fuse_reply_entry(req, &e);
+ return;
+
+err_out:
+ fuse_reply_err(req, ENOENT);
+}
+
+static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
+ uint64_t nlookup) {
+ (void) req;
+ assert(ino == FILE_INO || ino == FUSE_ROOT_ID);
+ lookup_cnt -= nlookup;
+ fuse_reply_none(req);
+}
+
+static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi) {
+ struct stat stbuf;
+
+ (void) fi;
+
+ memset(&stbuf, 0, sizeof(stbuf));
+ if (tfs_stat(ino, &stbuf) != 0)
+ fuse_reply_err(req, ENOENT);
+ else
+ fuse_reply_attr(req, &stbuf, NO_TIMEOUT);
+}
+
+struct dirbuf {
+ char *p;
+ size_t size;
+};
+
+static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
+ fuse_ino_t ino) {
+ struct stat stbuf;
+ size_t oldsize = b->size;
+ b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
+ b->p = (char *) realloc(b->p, b->size);
+ memset(&stbuf, 0, sizeof(stbuf));
+ stbuf.st_ino = ino;
+ fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
+ b->size);
+}
+
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
+static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
+ off_t off, size_t maxsize) {
+ if (off < bufsize)
+ return fuse_reply_buf(req, buf + off,
+ min(bufsize - off, maxsize));
+ else
+ return fuse_reply_buf(req, NULL, 0);
+}
+
+static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
+ off_t off, struct fuse_file_info *fi) {
+ (void) fi;
+
+ if (ino != FUSE_ROOT_ID)
+ fuse_reply_err(req, ENOTDIR);
+ else {
+ struct dirbuf b;
+
+ memset(&b, 0, sizeof(b));
+ dirbuf_add(req, &b, FILE_NAME, FILE_INO);
+ reply_buf_limited(req, b.p, b.size, off, size);
+ free(b.p);
+ }
+}
+
+static void tfs_open(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi) {
+
+ /* Make cache persistent even if file is closed,
+ this makes it easier to see the effects */
+ fi->keep_cache = 1;
+
+ if (ino == FUSE_ROOT_ID)
+ fuse_reply_err(req, EISDIR);
+ else if ((fi->flags & ACCESS_MASK) != O_RDONLY)
+ fuse_reply_err(req, EACCES);
+ else if (ino == FILE_INO)
+ fuse_reply_open(req, fi);
+ else {
+ // This should not happen
+ fprintf(stderr, "Got open for non-existing inode!\n");
+ fuse_reply_err(req, ENOENT);
+ }
+}
+
+static void tfs_read(fuse_req_t req, fuse_ino_t ino, size_t size,
+ off_t off, struct fuse_file_info *fi) {
+ (void) fi;
+
+ assert(ino == FILE_INO);
+ reply_buf_limited(req, file_contents, file_size, off, size);
+}
+
+static void tfs_retrieve_reply(fuse_req_t req, void *cookie, fuse_ino_t ino,
+ off_t offset, struct fuse_bufvec *data) {
+ struct fuse_bufvec bufv;
+ char buf[MAX_STR_LEN];
+ char *expected;
+ ssize_t ret;
+
+ assert(ino == FILE_INO);
+ assert(offset == 0);
+ expected = (char*) cookie;
+
+ bufv.count = 1;
+ bufv.idx = 0;
+ bufv.off = 0;
+ bufv.buf[0].size = MAX_STR_LEN;
+ bufv.buf[0].mem = buf;
+ bufv.buf[0].flags = 0;
+
+ ret = fuse_buf_copy(&bufv, data, 0);
+ assert(ret > 0);
+ assert(strncmp(buf, expected, ret) == 0);
+ free(expected);
+ retrieve_status = 2;
+ fuse_reply_none(req);
+}
+
+
+static struct fuse_lowlevel_ops tfs_oper = {
+ .lookup = tfs_lookup,
+ .getattr = tfs_getattr,
+ .readdir = tfs_readdir,
+ .open = tfs_open,
+ .read = tfs_read,
+ .forget = tfs_forget,
+ .retrieve_reply = tfs_retrieve_reply,
+};
+
+static void* update_fs(void *data) {
+ struct fuse_session *se = (struct fuse_session*) data;
+ struct tm *now;
+ time_t t;
+ struct fuse_bufvec bufv;
+
+ while(1) {
+ t = time(NULL);
+ now = localtime(&t);
+ assert(now != NULL);
+
+ file_size = strftime(file_contents, MAX_STR_LEN,
+ "The current time is %H:%M:%S\n", now);
+ assert(file_size != 0);
+ if (!options.no_notify && lookup_cnt) {
+ /* Only send notification if the kernel
+ is aware of the inode */
+ bufv.count = 1;
+ bufv.idx = 0;
+ bufv.off = 0;
+ bufv.buf[0].size = file_size;
+ bufv.buf[0].mem = file_contents;
+ bufv.buf[0].flags = 0;
+ assert(fuse_lowlevel_notify_store(se, FILE_INO, 0,
+ &bufv, 0) == 0);
+
+ /* To make sure that everything worked correctly, ask the
+ kernel to send us back the stored data */
+ assert(fuse_lowlevel_notify_retrieve
+ (se, FILE_INO, MAX_STR_LEN, 0,
+ (void*) strdup(file_contents)) == 0);
+ if(retrieve_status == 0)
+ retrieve_status = 1;
+ }
+ sleep(options.update_interval);
+ }
+ return NULL;
+}
+
+static void show_help(const char *progname)
+{
+ printf("usage: %s [options] <mountpoint>\n\n", progname);
+ printf("File-system specific options:\n"
+ " --update-interval=<secs> Update-rate of file system contents\n"
+ " --no-notify Disable kernel notifications\n"
+ "\n");
+}
+
+int main(int argc, char *argv[]) {
+ struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
+ struct fuse_session *se;
+ struct fuse_cmdline_opts opts;
+ pthread_t updater;
+ int ret = -1;
+
+ if (fuse_opt_parse(&args, &options, option_spec,
+ opt_proc) == -1)
+ return 1;
+
+ if (fuse_parse_cmdline(&args, &opts) != 0)
+ return 1;
+ if (opts.show_help) {
+ show_help(argv[0]);
+ fuse_cmdline_help();
+ fuse_lowlevel_help();
+ fuse_mount_help();
+ ret = 0;
+ goto err_out1;
+ } else if (opts.show_version) {
+ printf("FUSE library version %s\n", fuse_pkgversion());
+ fuse_lowlevel_version();
+ fuse_mount_version();
+ ret = 0;
+ goto err_out1;
+ }
+
+ se = fuse_session_new(&args, &tfs_oper,
+ sizeof(tfs_oper), NULL);
+ if (se == NULL)
+ goto err_out1;
+
+ if (fuse_set_signal_handlers(se) != 0)
+ goto err_out2;
+
+ if (fuse_session_mount(se, opts.mountpoint) != 0)
+ goto err_out3;
+
+ fuse_daemonize(opts.foreground);
+
+ /* Start thread to update file contents */
+ ret = pthread_create(&updater, NULL, update_fs, (void *)se);
+ if (ret != 0) {
+ fprintf(stderr, "pthread_create failed with %s\n",
+ strerror(ret));
+ goto err_out3;
+ }
+
+ /* Block until ctrl+c or fusermount -u */
+ if (opts.singlethread)
+ ret = fuse_session_loop(se);
+ else
+ ret = fuse_session_loop_mt(se);
+
+ assert(retrieve_status != 1);
+ fuse_session_unmount(se);
+err_out3:
+ fuse_remove_signal_handlers(se);
+err_out2:
+ fuse_session_destroy(se);
+err_out1:
+ free(opts.mountpoint);
+ fuse_opt_free_args(&args);
+
+ return ret ? 1 : 0;
+}
+
+
+/**
+ * Local Variables:
+ * mode: c
+ * indent-tabs-mode: nil
+ * c-basic-offset: 4
+ * End:
+ */
+++ /dev/null
-/*
- FUSE: Filesystem in Userspace
- Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
-
- This program can be distributed under the terms of the GNU GPL.
- See the file COPYING.
-*/
-
-/** @file
- * @tableofcontents
- *
- * This example implements a file system with a single file whose
- * contents change dynamically: it always contains the current time.
- *
- * While timefs2.c uses fuse_lowlevel_notify_store() to actively push
- * the updated data into the kernel cache, this example uses
- * fuse_lowlevel_notify_inval_inode() to notify the kernel that the
- * cache has to be invalidated - but the kernel still has to explicitly
- * request the updated data on the next read.
- *
- * To see the effect, first start the file system with the
- * ``--no-notify`` option:
- *
- * $ timefs --update-interval=1 --no-notify mnt/
- *
- * Observe that the output never changes, even though the file system
- * updates it once per second. This is because the contents are cached
- * in the kernel:
- *
- * $ for i in 1 2 3 4 5; do
- * > cat mnt/current_time
- * > sleep 1
- * > done
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- *
- * If you instead enable the notification functions, the changes become
- * visible:
- *
- * $ timefs --update-interval=1 mnt/
- * $ for i in 1 2 3 4 5; do
- * > cat mnt/current_time
- * > sleep 1
- * > done
- * The current time is 15:58:40
- * The current time is 15:58:41
- * The current time is 15:58:42
- * The current time is 15:58:43
- * The current time is 15:58:44
- *
- * \section section_compile compiling this example
- *
- * gcc -Wall timefs1.c `pkg-config fuse3 --cflags --libs` -o timefs1
- *
- * \section section_source the complete source
- * \include timefs1.c
- */
-
-
-#define FUSE_USE_VERSION 30
-
-#include <config.h>
-
-#include <fuse_lowlevel.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <assert.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <pthread.h>
-
-/* We can't actually tell the kernel that there is no
- timeout, so we just send a big value */
-#define NO_TIMEOUT 500000
-
-/* We cannot check directly if e.g. O_RDONLY is set, since this is not
- * an individual bit (cf. open(2)) */
-#define ACCESS_MASK (O_RDONLY | O_WRONLY | O_RDWR)
-
-#define MAX_STR_LEN 128
-#define FILE_INO 2
-#define FILE_NAME "current_time"
-static char file_contents[MAX_STR_LEN];
-static int lookup_cnt = 0;
-static size_t file_size;
-
-/* Command line parsing */
-struct options {
- int no_notify;
- int update_interval;
-};
-static struct options options = {
- .no_notify = 0,
- .update_interval = 1,
-};
-
-#define OPTION(t, p) \
- { t, offsetof(struct options, p), 1 }
-static const struct fuse_opt option_spec[] = {
- OPTION("--no-notify", no_notify),
- OPTION("--update-interval=%d", update_interval),
- FUSE_OPT_END
-};
-
-static int opt_proc(void *data, const char *arg, int key,
- struct fuse_args *outargs) {
- (void) outargs; (void) data; (void) arg;
- (void) key;
- return 1;
-}
-
-static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
- stbuf->st_ino = ino;
- if (ino == FUSE_ROOT_ID) {
- stbuf->st_mode = S_IFDIR | 0755;
- stbuf->st_nlink = 1;
- }
-
- else if (ino == FILE_INO) {
- stbuf->st_mode = S_IFREG | 0444;
- stbuf->st_nlink = 1;
- stbuf->st_size = file_size;
- }
-
- else
- return -1;
-
- return 0;
-}
-
-static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
- const char *name) {
- struct fuse_entry_param e;
- memset(&e, 0, sizeof(e));
-
- if (parent != FUSE_ROOT_ID)
- goto err_out;
- else if (strcmp(name, FILE_NAME) == 0) {
- e.ino = FILE_INO;
- lookup_cnt++;
- } else
- goto err_out;
-
- e.attr_timeout = NO_TIMEOUT;
- e.entry_timeout = NO_TIMEOUT;
- if (tfs_stat(e.ino, &e.attr) != 0)
- goto err_out;
- fuse_reply_entry(req, &e);
- return;
-
-err_out:
- fuse_reply_err(req, ENOENT);
-}
-
-static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
- uint64_t nlookup) {
- (void) req;
- assert(ino == FILE_INO || ino == FUSE_ROOT_ID);
- lookup_cnt -= nlookup;
- fuse_reply_none(req);
-}
-
-static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi) {
- struct stat stbuf;
-
- (void) fi;
-
- memset(&stbuf, 0, sizeof(stbuf));
- if (tfs_stat(ino, &stbuf) != 0)
- fuse_reply_err(req, ENOENT);
- else
- fuse_reply_attr(req, &stbuf, NO_TIMEOUT);
-}
-
-struct dirbuf {
- char *p;
- size_t size;
-};
-
-static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
- fuse_ino_t ino) {
- struct stat stbuf;
- size_t oldsize = b->size;
- b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
- b->p = (char *) realloc(b->p, b->size);
- memset(&stbuf, 0, sizeof(stbuf));
- stbuf.st_ino = ino;
- fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
- b->size);
-}
-
-#define min(x, y) ((x) < (y) ? (x) : (y))
-
-static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
- off_t off, size_t maxsize) {
- if (off < bufsize)
- return fuse_reply_buf(req, buf + off,
- min(bufsize - off, maxsize));
- else
- return fuse_reply_buf(req, NULL, 0);
-}
-
-static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
- off_t off, struct fuse_file_info *fi) {
- (void) fi;
-
- if (ino != FUSE_ROOT_ID)
- fuse_reply_err(req, ENOTDIR);
- else {
- struct dirbuf b;
-
- memset(&b, 0, sizeof(b));
- dirbuf_add(req, &b, FILE_NAME, FILE_INO);
- reply_buf_limited(req, b.p, b.size, off, size);
- free(b.p);
- }
-}
-
-static void tfs_open(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi) {
-
- /* Make cache persistent even if file is closed,
- this makes it easier to see the effects */
- fi->keep_cache = 1;
-
- if (ino == FUSE_ROOT_ID)
- fuse_reply_err(req, EISDIR);
- else if ((fi->flags & ACCESS_MASK) != O_RDONLY)
- fuse_reply_err(req, EACCES);
- else if (ino == FILE_INO)
- fuse_reply_open(req, fi);
- else {
- // This should not happen
- fprintf(stderr, "Got open for non-existing inode!\n");
- fuse_reply_err(req, ENOENT);
- }
-}
-
-static void tfs_read(fuse_req_t req, fuse_ino_t ino, size_t size,
- off_t off, struct fuse_file_info *fi) {
- (void) fi;
-
- assert(ino == FILE_INO);
- reply_buf_limited(req, file_contents, file_size, off, size);
-}
-
-static struct fuse_lowlevel_ops tfs_oper = {
- .lookup = tfs_lookup,
- .getattr = tfs_getattr,
- .readdir = tfs_readdir,
- .open = tfs_open,
- .read = tfs_read,
- .forget = tfs_forget,
-};
-
-static void* update_fs(void *data) {
- struct fuse_session *se = (struct fuse_session*) data;
- struct tm *now;
- time_t t;
-
- while(1) {
- t = time(NULL);
- now = localtime(&t);
- assert(now != NULL);
-
- file_size = strftime(file_contents, MAX_STR_LEN,
- "The current time is %H:%M:%S\n", now);
- assert(file_size != 0);
- if (!options.no_notify && lookup_cnt) {
- /* Only send notification if the kernel
- is aware of the inode */
- assert(fuse_lowlevel_notify_inval_inode
- (se, FILE_INO, 0, 0) == 0);
- }
- sleep(options.update_interval);
- }
- return NULL;
-}
-
-static void show_help(const char *progname)
-{
- printf("usage: %s [options] <mountpoint>\n\n", progname);
- printf("File-system specific options:\n"
- " --update-interval=<secs> Update-rate of file system contents\n"
- " --no-notify Disable kernel notifications\n"
- "\n");
-}
-
-int main(int argc, char *argv[]) {
- struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
- struct fuse_session *se;
- struct fuse_cmdline_opts opts;
- pthread_t updater;
- int ret = -1;
-
- if (fuse_opt_parse(&args, &options, option_spec,
- opt_proc) == -1)
- return 1;
-
- if (fuse_parse_cmdline(&args, &opts) != 0) {
- ret = 1;
- goto err_out1;
- }
-
- if (opts.show_help) {
- show_help(argv[0]);
- fuse_cmdline_help();
- fuse_lowlevel_help();
- fuse_mount_help();
- ret = 0;
- goto err_out1;
- } else if (opts.show_version) {
- printf("FUSE library version %s\n", fuse_pkgversion());
- fuse_lowlevel_version();
- fuse_mount_version();
- ret = 0;
- goto err_out1;
- }
-
- se = fuse_session_new(&args, &tfs_oper,
- sizeof(tfs_oper), NULL);
- if (se == NULL)
- goto err_out1;
-
- if (fuse_set_signal_handlers(se) != 0)
- goto err_out2;
-
- if (fuse_session_mount(se, opts.mountpoint) != 0)
- goto err_out3;
-
- fuse_daemonize(opts.foreground);
-
- /* Start thread to update file contents */
- ret = pthread_create(&updater, NULL, update_fs, (void *)se);
- if (ret != 0) {
- fprintf(stderr, "pthread_create failed with %s\n",
- strerror(ret));
- goto err_out3;
- }
-
- /* Block until ctrl+c or fusermount -u */
- if (opts.singlethread)
- ret = fuse_session_loop(se);
- else
- ret = fuse_session_loop_mt(se);
-
- fuse_session_unmount(se);
-err_out3:
- fuse_remove_signal_handlers(se);
-err_out2:
- fuse_session_destroy(se);
-err_out1:
- fuse_opt_free_args(&args);
- free(opts.mountpoint);
-
- return ret ? 1 : 0;
-}
-
-
-/**
- * Local Variables:
- * mode: c
- * indent-tabs-mode: nil
- * c-basic-offset: 4
- * End:
- */
+++ /dev/null
-/*
- FUSE: Filesystem in Userspace
- Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
-
- This program can be distributed under the terms of the GNU GPL.
- See the file COPYING.
-*/
-
-/** @file
- * @tableofcontents
- *
- * This example implements a file system with a single file whose
- * contents change dynamically: it always contains the current time.
- *
- * While timefs1.c uses fuse_lowlevel_notify_inval_inode() to let the
- * kernel know that it has to invalidate the cache, this example
- * actively pushes the updated data into the kernel cache using
- * fuse_lowlevel_notify_store().
- *
- * To see the effect, first start the file system with the
- * ``--no-notify`` option:
- *
- * $ timefs --update-interval=1 --no-notify mnt/
- *
- * Observe that the output never changes, even though the file system
- * updates it once per second. This is because the contents are cached
- * in the kernel:
- *
- * $ for i in 1 2 3 4 5; do
- * > cat mnt/current_time
- * > sleep 1
- * > done
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- * The current time is 15:58:18
- *
- * If you instead enable the notification functions, the changes become
- * visible:
- *
- * $ timefs --update-interval=1 mnt/
- * $ for i in 1 2 3 4 5; do
- * > cat mnt/current_time
- * > sleep 1
- * > done
- * The current time is 15:58:40
- * The current time is 15:58:41
- * The current time is 15:58:42
- * The current time is 15:58:43
- * The current time is 15:58:44
- *
- * \section section_compile compiling this example
- *
- * gcc -Wall timefs2.c `pkg-config fuse3 --cflags --libs` -o timefs2
- *
- * \section section_source the complete source
- * \include timefs2.c
- */
-
-
-#define FUSE_USE_VERSION 30
-
-#include <config.h>
-
-#include <fuse_lowlevel.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <assert.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <pthread.h>
-
-/* We can't actually tell the kernel that there is no
- timeout, so we just send a big value */
-#define NO_TIMEOUT 500000
-
-/* We cannot check directly if e.g. O_RDONLY is set, since this is not
- * an individual bit (cf. open(2)) */
-#define ACCESS_MASK (O_RDONLY | O_WRONLY | O_RDWR)
-
-#define MAX_STR_LEN 128
-#define FILE_INO 2
-#define FILE_NAME "current_time"
-static char file_contents[MAX_STR_LEN];
-static int lookup_cnt = 0;
-static size_t file_size;
-
-/* Keep track if we ever stored data (==1), and
- received it back correctly (==2) */
-static int retrieve_status = 0;
-
-/* Command line parsing */
-struct options {
- int no_notify;
- int update_interval;
-};
-static struct options options = {
- .no_notify = 0,
- .update_interval = 1,
-};
-
-#define OPTION(t, p) \
- { t, offsetof(struct options, p), 1 }
-static const struct fuse_opt option_spec[] = {
- OPTION("--no-notify", no_notify),
- OPTION("--update-interval=%d", update_interval),
- FUSE_OPT_END
-};
-
-static int opt_proc(void *data, const char *arg, int key,
- struct fuse_args *outargs) {
- (void) outargs; (void) data; (void) arg;
- (void) key;
- return 1;
-}
-
-static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
- stbuf->st_ino = ino;
- if (ino == FUSE_ROOT_ID) {
- stbuf->st_mode = S_IFDIR | 0755;
- stbuf->st_nlink = 1;
- }
-
- else if (ino == FILE_INO) {
- stbuf->st_mode = S_IFREG | 0444;
- stbuf->st_nlink = 1;
- stbuf->st_size = file_size;
- }
-
- else
- return -1;
-
- return 0;
-}
-
-static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
- const char *name) {
- struct fuse_entry_param e;
- memset(&e, 0, sizeof(e));
-
- if (parent != FUSE_ROOT_ID)
- goto err_out;
- else if (strcmp(name, FILE_NAME) == 0) {
- e.ino = FILE_INO;
- lookup_cnt++;
- } else
- goto err_out;
-
- e.attr_timeout = NO_TIMEOUT;
- e.entry_timeout = NO_TIMEOUT;
- if (tfs_stat(e.ino, &e.attr) != 0)
- goto err_out;
- fuse_reply_entry(req, &e);
- return;
-
-err_out:
- fuse_reply_err(req, ENOENT);
-}
-
-static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
- uint64_t nlookup) {
- (void) req;
- assert(ino == FILE_INO || ino == FUSE_ROOT_ID);
- lookup_cnt -= nlookup;
- fuse_reply_none(req);
-}
-
-static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi) {
- struct stat stbuf;
-
- (void) fi;
-
- memset(&stbuf, 0, sizeof(stbuf));
- if (tfs_stat(ino, &stbuf) != 0)
- fuse_reply_err(req, ENOENT);
- else
- fuse_reply_attr(req, &stbuf, NO_TIMEOUT);
-}
-
-struct dirbuf {
- char *p;
- size_t size;
-};
-
-static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
- fuse_ino_t ino) {
- struct stat stbuf;
- size_t oldsize = b->size;
- b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
- b->p = (char *) realloc(b->p, b->size);
- memset(&stbuf, 0, sizeof(stbuf));
- stbuf.st_ino = ino;
- fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
- b->size);
-}
-
-#define min(x, y) ((x) < (y) ? (x) : (y))
-
-static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
- off_t off, size_t maxsize) {
- if (off < bufsize)
- return fuse_reply_buf(req, buf + off,
- min(bufsize - off, maxsize));
- else
- return fuse_reply_buf(req, NULL, 0);
-}
-
-static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
- off_t off, struct fuse_file_info *fi) {
- (void) fi;
-
- if (ino != FUSE_ROOT_ID)
- fuse_reply_err(req, ENOTDIR);
- else {
- struct dirbuf b;
-
- memset(&b, 0, sizeof(b));
- dirbuf_add(req, &b, FILE_NAME, FILE_INO);
- reply_buf_limited(req, b.p, b.size, off, size);
- free(b.p);
- }
-}
-
-static void tfs_open(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi) {
-
- /* Make cache persistent even if file is closed,
- this makes it easier to see the effects */
- fi->keep_cache = 1;
-
- if (ino == FUSE_ROOT_ID)
- fuse_reply_err(req, EISDIR);
- else if ((fi->flags & ACCESS_MASK) != O_RDONLY)
- fuse_reply_err(req, EACCES);
- else if (ino == FILE_INO)
- fuse_reply_open(req, fi);
- else {
- // This should not happen
- fprintf(stderr, "Got open for non-existing inode!\n");
- fuse_reply_err(req, ENOENT);
- }
-}
-
-static void tfs_read(fuse_req_t req, fuse_ino_t ino, size_t size,
- off_t off, struct fuse_file_info *fi) {
- (void) fi;
-
- assert(ino == FILE_INO);
- reply_buf_limited(req, file_contents, file_size, off, size);
-}
-
-static void tfs_retrieve_reply(fuse_req_t req, void *cookie, fuse_ino_t ino,
- off_t offset, struct fuse_bufvec *data) {
- struct fuse_bufvec bufv;
- char buf[MAX_STR_LEN];
- char *expected;
- ssize_t ret;
-
- assert(ino == FILE_INO);
- assert(offset == 0);
- expected = (char*) cookie;
-
- bufv.count = 1;
- bufv.idx = 0;
- bufv.off = 0;
- bufv.buf[0].size = MAX_STR_LEN;
- bufv.buf[0].mem = buf;
- bufv.buf[0].flags = 0;
-
- ret = fuse_buf_copy(&bufv, data, 0);
- assert(ret > 0);
- assert(strncmp(buf, expected, ret) == 0);
- free(expected);
- retrieve_status = 2;
- fuse_reply_none(req);
-}
-
-
-static struct fuse_lowlevel_ops tfs_oper = {
- .lookup = tfs_lookup,
- .getattr = tfs_getattr,
- .readdir = tfs_readdir,
- .open = tfs_open,
- .read = tfs_read,
- .forget = tfs_forget,
- .retrieve_reply = tfs_retrieve_reply,
-};
-
-static void* update_fs(void *data) {
- struct fuse_session *se = (struct fuse_session*) data;
- struct tm *now;
- time_t t;
- struct fuse_bufvec bufv;
-
- while(1) {
- t = time(NULL);
- now = localtime(&t);
- assert(now != NULL);
-
- file_size = strftime(file_contents, MAX_STR_LEN,
- "The current time is %H:%M:%S\n", now);
- assert(file_size != 0);
- if (!options.no_notify && lookup_cnt) {
- /* Only send notification if the kernel
- is aware of the inode */
- bufv.count = 1;
- bufv.idx = 0;
- bufv.off = 0;
- bufv.buf[0].size = file_size;
- bufv.buf[0].mem = file_contents;
- bufv.buf[0].flags = 0;
- assert(fuse_lowlevel_notify_store(se, FILE_INO, 0,
- &bufv, 0) == 0);
-
- /* To make sure that everything worked correctly, ask the
- kernel to send us back the stored data */
- assert(fuse_lowlevel_notify_retrieve
- (se, FILE_INO, MAX_STR_LEN, 0,
- (void*) strdup(file_contents)) == 0);
- if(retrieve_status == 0)
- retrieve_status = 1;
- }
- sleep(options.update_interval);
- }
- return NULL;
-}
-
-static void show_help(const char *progname)
-{
- printf("usage: %s [options] <mountpoint>\n\n", progname);
- printf("File-system specific options:\n"
- " --update-interval=<secs> Update-rate of file system contents\n"
- " --no-notify Disable kernel notifications\n"
- "\n");
-}
-
-int main(int argc, char *argv[]) {
- struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
- struct fuse_session *se;
- struct fuse_cmdline_opts opts;
- pthread_t updater;
- int ret = -1;
-
- if (fuse_opt_parse(&args, &options, option_spec,
- opt_proc) == -1)
- return 1;
-
- if (fuse_parse_cmdline(&args, &opts) != 0)
- return 1;
- if (opts.show_help) {
- show_help(argv[0]);
- fuse_cmdline_help();
- fuse_lowlevel_help();
- fuse_mount_help();
- ret = 0;
- goto err_out1;
- } else if (opts.show_version) {
- printf("FUSE library version %s\n", fuse_pkgversion());
- fuse_lowlevel_version();
- fuse_mount_version();
- ret = 0;
- goto err_out1;
- }
-
- se = fuse_session_new(&args, &tfs_oper,
- sizeof(tfs_oper), NULL);
- if (se == NULL)
- goto err_out1;
-
- if (fuse_set_signal_handlers(se) != 0)
- goto err_out2;
-
- if (fuse_session_mount(se, opts.mountpoint) != 0)
- goto err_out3;
-
- fuse_daemonize(opts.foreground);
-
- /* Start thread to update file contents */
- ret = pthread_create(&updater, NULL, update_fs, (void *)se);
- if (ret != 0) {
- fprintf(stderr, "pthread_create failed with %s\n",
- strerror(ret));
- goto err_out3;
- }
-
- /* Block until ctrl+c or fusermount -u */
- if (opts.singlethread)
- ret = fuse_session_loop(se);
- else
- ret = fuse_session_loop_mt(se);
-
- assert(retrieve_status != 1);
- fuse_session_unmount(se);
-err_out3:
- fuse_remove_signal_handlers(se);
-err_out2:
- fuse_session_destroy(se);
-err_out1:
- free(opts.mountpoint);
- fuse_opt_free_args(&args);
-
- return ret ? 1 : 0;
-}
-
-
-/**
- * Local Variables:
- * mode: c
- * indent-tabs-mode: nil
- * c-basic-offset: 4
- * End:
- */
+++ /dev/null
-/*
- FUSE: Filesystem in Userspace
- Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
-
- This program can be distributed under the terms of the GNU GPL.
- See the file COPYING.
-*/
-
-/** @file
- * @tableofcontents
- *
- * This example implements a file system with a single file whose
- * file name changes dynamically to reflect the current time.
- *
- * It illustrates the use of the fuse_lowlevel_notify_inval_entry()
- * function.
- *
- * To see the effect, first start the file system with the
- * ``--no-notify``
- *
- * $ timefs --update-interval=1 --timeout 30 --no-notify mnt/
- *
- * Observe that `ls` always prints the correct directory contents
- * (since `readdir` output is not cached)::
- *
- * $ ls mnt; sleep 1; ls mnt; sleep 1; ls mnt
- * Time_is_15h_48m_33s current_time
- * Time_is_15h_48m_34s current_time
- * Time_is_15h_48m_35s current_time
- *
- * However, if you try to access a file by name the kernel will
- * report that it still exists:
- *
- * $ file=$(ls mnt/); echo $file
- * Time_is_15h_50m_09s
- * $ sleep 5; stat mnt/$file
- * File: ‘mnt/Time_is_15h_50m_09s’
- * Size: 32 Blocks: 0 IO Block: 4096 regular file
- * Device: 2ah/42d Inode: 3 Links: 1
- * Access: (0444/-r--r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
- * Access: 1969-12-31 16:00:00.000000000 -0800
- * Modify: 1969-12-31 16:00:00.000000000 -0800
- * Change: 1969-12-31 16:00:00.000000000 -0800
- * Birth: -
- *
- * Only once the kernel cache timeout has been reached will the stat
- * call fail:
- *
- * $ sleep 30; stat mnt/$file
- * stat: cannot stat ‘mnt/Time_is_15h_50m_09s’: No such file or directory
- *
- * In contrast, if you enable notifications you will be unable to stat
- * the file as soon as the file system updates its name:
- *
- * $ timefs --update-interval=1 --timeout 30 --no-notify mnt/
- * $ file=$(ls mnt/); stat mnt/$file
- * File: ‘mnt/Time_is_20h_42m_11s’
- * Size: 0 Blocks: 0 IO Block: 4096 regular empty file
- * Device: 2ah/42d Inode: 2 Links: 1
- * Access: (0000/----------) Uid: ( 0/ root) Gid: ( 0/ root)
- * Access: 1969-12-31 16:00:00.000000000 -0800
- * Modify: 1969-12-31 16:00:00.000000000 -0800
- * Change: 1969-12-31 16:00:00.000000000 -0800
- * Birth: -
- * $ sleep 1; stat mnt/$file
- * stat: cannot stat ‘mnt/Time_is_20h_42m_11s’: No such file or directory
- *
- * \section section_compile compiling this example
- *
- * gcc -Wall timefs3.c `pkg-config fuse3 --cflags --libs` -o timefs3
- *
- * \section section_source the complete source
- * \include timefs3.c
- */
-
-
-#define FUSE_USE_VERSION 30
-
-#include <config.h>
-
-#include <fuse_lowlevel.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <assert.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <pthread.h>
-
-#define MAX_STR_LEN 128
-static char file_name[MAX_STR_LEN];
-static fuse_ino_t file_ino = 2;
-static int lookup_cnt = 0;
-
-/* Command line parsing */
-struct options {
- int no_notify;
- float timeout;
- int update_interval;
-};
-static struct options options = {
- .timeout = 5,
- .no_notify = 0,
- .update_interval = 1,
-};
-
-#define OPTION(t, p) \
- { t, offsetof(struct options, p), 1 }
-static const struct fuse_opt option_spec[] = {
- OPTION("--no-notify", no_notify),
- OPTION("--update-interval=%d", update_interval),
- OPTION("--timeout=%f", timeout),
- FUSE_OPT_END
-};
-
-static int opt_proc(void *data, const char *arg, int key,
- struct fuse_args *outargs) {
- (void) outargs; (void) data; (void) arg;
- (void) key;
- return 1;
-}
-
-static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
- stbuf->st_ino = ino;
- if (ino == FUSE_ROOT_ID) {
- stbuf->st_mode = S_IFDIR | 0755;
- stbuf->st_nlink = 1;
- }
-
- else if (ino == file_ino) {
- stbuf->st_mode = S_IFREG | 0000;
- stbuf->st_nlink = 1;
- stbuf->st_size = 0;
- }
-
- else
- return -1;
-
- return 0;
-}
-
-static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
- const char *name) {
- struct fuse_entry_param e;
- memset(&e, 0, sizeof(e));
-
- if (parent != FUSE_ROOT_ID)
- goto err_out;
- else if (strcmp(name, file_name) == 0) {
- e.ino = file_ino;
- lookup_cnt++;
- } else
- goto err_out;
-
- e.attr_timeout = options.timeout;
- e.entry_timeout = options.timeout;
- if (tfs_stat(e.ino, &e.attr) != 0)
- goto err_out;
- fuse_reply_entry(req, &e);
- return;
-
-err_out:
- fuse_reply_err(req, ENOENT);
-}
-
-static void tfs_forget (fuse_req_t req, fuse_ino_t ino,
- uint64_t nlookup) {
- (void) req;
- assert(ino == file_ino || ino == FUSE_ROOT_ID);
- lookup_cnt -= nlookup;
- fuse_reply_none(req);
-}
-
-
-static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi) {
- struct stat stbuf;
-
- (void) fi;
-
- memset(&stbuf, 0, sizeof(stbuf));
- if (tfs_stat(ino, &stbuf) != 0)
- fuse_reply_err(req, ENOENT);
- else
- fuse_reply_attr(req, &stbuf, options.timeout);
-}
-
-struct dirbuf {
- char *p;
- size_t size;
-};
-
-static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
- fuse_ino_t ino) {
- struct stat stbuf;
- size_t oldsize = b->size;
- b->size += fuse_add_direntry(req, NULL, 0, name, NULL, 0);
- b->p = (char *) realloc(b->p, b->size);
- memset(&stbuf, 0, sizeof(stbuf));
- stbuf.st_ino = ino;
- fuse_add_direntry(req, b->p + oldsize, b->size - oldsize, name, &stbuf,
- b->size);
-}
-
-#define min(x, y) ((x) < (y) ? (x) : (y))
-
-static int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
- off_t off, size_t maxsize) {
- if (off < bufsize)
- return fuse_reply_buf(req, buf + off,
- min(bufsize - off, maxsize));
- else
- return fuse_reply_buf(req, NULL, 0);
-}
-
-static void tfs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
- off_t off, struct fuse_file_info *fi) {
- (void) fi;
-
- if (ino != FUSE_ROOT_ID)
- fuse_reply_err(req, ENOTDIR);
- else {
- struct dirbuf b;
-
- memset(&b, 0, sizeof(b));
- dirbuf_add(req, &b, file_name, file_ino);
- reply_buf_limited(req, b.p, b.size, off, size);
- free(b.p);
- }
-}
-
-static struct fuse_lowlevel_ops tfs_oper = {
- .lookup = tfs_lookup,
- .getattr = tfs_getattr,
- .readdir = tfs_readdir,
- .forget = tfs_forget,
-};
-
-static void* update_fs(void *data) {
- struct fuse_session *se = (struct fuse_session*) data;
- struct tm *now;
- char *old_name;
- time_t t;
- ssize_t ret;
-
- while(1) {
- t = time(NULL);
- now = localtime(&t);
- assert(now != NULL);
-
- old_name = strdup(file_name);
- ret = strftime(file_name, MAX_STR_LEN,
- "Time_is_%Hh_%Mm_%Ss", now);
- assert(ret != 0);
-
- if (!options.no_notify && lookup_cnt)
- assert(fuse_lowlevel_notify_inval_entry
- (se, FUSE_ROOT_ID, old_name, strlen(old_name)) == 0);
- free(old_name);
- sleep(options.update_interval);
- }
- return NULL;
-}
-
-static void show_help(const char *progname)
-{
- printf("usage: %s [options] <mountpoint>\n\n", progname);
- printf("File-system specific options:\n"
- " --timeout=<secs> Timeout for kernel caches\n"
- " --update-interval=<secs> Update-rate of file system contents\n"
- " --no-notify Disable kernel notifications\n"
- "\n");
-}
-
-int main(int argc, char *argv[]) {
- struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
- struct fuse_session *se;
- struct fuse_cmdline_opts opts;
- pthread_t updater;
- int ret = -1;
-
- if (fuse_opt_parse(&args, &options, option_spec,
- opt_proc) == -1)
- return 1;
-
- if (fuse_parse_cmdline(&args, &opts) != 0)
- return 1;
- if (opts.show_help) {
- show_help(argv[0]);
- fuse_cmdline_help();
- fuse_lowlevel_help();
- fuse_mount_help();
- ret = 0;
- goto err_out1;
- } else if (opts.show_version) {
- printf("FUSE library version %s\n", fuse_pkgversion());
- fuse_lowlevel_version();
- fuse_mount_version();
- ret = 0;
- goto err_out1;
- }
-
- se = fuse_session_new(&args, &tfs_oper,
- sizeof(tfs_oper), NULL);
- if (se == NULL)
- goto err_out1;
-
- if (fuse_set_signal_handlers(se) != 0)
- goto err_out2;
-
- if (fuse_session_mount(se, opts.mountpoint) != 0)
- goto err_out3;
-
- fuse_daemonize(opts.foreground);
-
- /* Start thread to update file contents */
- ret = pthread_create(&updater, NULL, update_fs, (void *)se);
- if (ret != 0) {
- fprintf(stderr, "pthread_create failed with %s\n",
- strerror(ret));
- goto err_out3;
- }
-
- /* Block until ctrl+c or fusermount -u */
- if (opts.singlethread)
- ret = fuse_session_loop(se);
- else
- ret = fuse_session_loop_mt(se);
-
- fuse_session_unmount(se);
-err_out3:
- fuse_remove_signal_handlers(se);
-err_out2:
- fuse_session_destroy(se);
-err_out1:
- free(opts.mountpoint);
- fuse_opt_free_args(&args);
-
- return ret ? 1 : 0;
-}
-
-
-/**
- * Local Variables:
- * mode: c
- * indent-tabs-mode: nil
- * c-basic-offset: 4
- * End:
- */
else:
umount(mount_process, mnt_dir)
-@pytest.mark.parametrize("name", ('timefs1', 'timefs2'))
+@pytest.mark.parametrize("name",
+ ('notify_inval_inode',
+ 'notify_store_retrieve'))
@pytest.mark.parametrize("options", LL_OPTIONS)
@pytest.mark.parametrize("notify", (True, False))
-def test_timefs12(tmpdir, name, options, notify):
+def test_notify1(tmpdir, name, options, notify):
mnt_dir = str(tmpdir)
cmdline = base_cmdline + \
[ pjoin(basename, 'example', name),
umount(mount_process, mnt_dir)
@pytest.mark.parametrize("notify", (True, False))
-def test_timefs3(tmpdir, notify):
+def test_notify_inval_entry(tmpdir, notify):
mnt_dir = str(tmpdir)
cmdline = base_cmdline + \
- [ pjoin(basename, 'example', 'timefs3'),
+ [ pjoin(basename, 'example', 'notify_inval_entry'),
'-f', '--update-interval=2',
'--timeout=4', mnt_dir ]
if not notify:
projects / qemu-gpiodev / libfuse.git / commitdiff