Unreleased Changes
==================
+* There are new ``timefs1`` and ``timefs2`` examples that demonstrate
+ the use of the `fuse_lowlevel_notify_store` and
+ `fuse_lowlevel_notify_inval_inode` functions.
+
* The ``-o big_writes`` mount option has been removed. It is now
always active. File systems that want to limit the size of write
requests should use the ``-o max_write=<N>`` option instead.
/fselclient
/cusexmp
/fuse_lo-plus
+/timefs1
+/timefs2
AM_CPPFLAGS = -I$(top_srcdir)/include -D_REENTRANT
noinst_HEADERS = fioc.h
noinst_PROGRAMS = fusexmp fusexmp_fh null hello hello_ll fioc fioclient \
- fsel fselclient cusexmp fuse_lo-plus
+ fsel fselclient cusexmp fuse_lo-plus timefs1 timefs2
LDADD = ../lib/libfuse3.la
fusexmp_fh_LDADD = ../lib/libfuse3.la @fusexmp_fh_libs@
fselclient_CPPFLAGS =
fselclient_LDFLAGS =
fselclient_LDADD =
-
--- /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.
+
+ 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
+
+*/
+
+#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;
+}
+
+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 || opts.show_version) {
+ ret = 1;
+ 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.
+
+ 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
+
+*/
+
+#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;
+ 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);
+ }
+ sleep(options.update_interval);
+ }
+ return NULL;
+}
+
+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 || opts.show_version) {
+ ret = 1;
+ 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:
+ */
import filecmp
import errno
from tempfile import NamedTemporaryFile
-from util import wait_for_mount, umount, cleanup, base_cmdline
+from util import (wait_for_mount, umount, cleanup, base_cmdline,
+ safe_sleep)
from os.path import join as pjoin
basename = pjoin(os.path.dirname(__file__), '..')
else:
umount(mount_process, mnt_dir)
+@pytest.mark.parametrize("name", ('timefs1', 'timefs2'))
+@pytest.mark.parametrize("options", LL_OPTIONS)
+@pytest.mark.parametrize("notify", (True, False))
+def test_timefs(tmpdir, name, options, notify):
+ mnt_dir = str(tmpdir)
+ cmdline = base_cmdline + \
+ [ pjoin(basename, 'example', name),
+ '-f', '--update-interval=1', mnt_dir ] + options
+ if not notify:
+ cmdline.append('--no-notify')
+ mount_process = subprocess.Popen(cmdline)
+ try:
+ wait_for_mount(mount_process, mnt_dir)
+ filename = pjoin(mnt_dir, 'current_time')
+ with open(filename, 'r') as fh:
+ read1 = fh.read()
+ safe_sleep(2)
+ with open(filename, 'r') as fh:
+ read2 = fh.read()
+ if notify:
+ assert read1 != read2
+ else:
+ assert read1 == read2
+ except:
+ cleanup(mnt_dir)
+ raise
+ else:
+ umount(mount_process, mnt_dir)
+
def checked_unlink(filename, path, isdir=False):
fullname = pjoin(path, filename)
if isdir:
projects / qemu-gpiodev / libfuse.git / commitdiff