ulockmgr
diff --git a/ChangeLog b/ChangeLog
index 744ab42..ad21e97 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2006-09-10 Miklos Szeredi <miklos@szeredi.hu>
+
+ * Released 2.6.0-rc1
+
+2006-09-10 Miklos Szeredi <miklos@szeredi.hu>
+
+ * kernel: Fix unlock on close for kernels < 2.6.18
+
+ * Add ulockmgr library & server. This can be used for handling
+ file locking requests either directly from libfuse or over a
+ network, etc. This first version is not optimized and the number
+ of file descriptors it uses may get out of hand
+
2006-09-07 Miklos Szeredi <miklos@szeredi.hu>
* lib: Add interrupt support to high level library, which may be
diff --git a/configure.in b/configure.in
index 063f68f..f21326e 100644
--- a/configure.in
+++ b/configure.in
@@ -1,4 +1,4 @@
-AC_INIT(fuse, 2.6.0-pre3)
+AC_INIT(fuse, 2.6.0-rc1)
AC_CANONICAL_TARGET
AM_INIT_AUTOMAKE
AM_CONFIG_HEADER(include/config.h)
diff --git a/example/Makefile.am b/example/Makefile.am
index 1f31cfc..9fe35e8 100644
--- a/example/Makefile.am
+++ b/example/Makefile.am
@@ -3,9 +3,5 @@
AM_CPPFLAGS = -I$(top_srcdir)/include
noinst_PROGRAMS = fusexmp fusexmp_fh null hello hello_ll
-fusexmp_SOURCES = fusexmp.c
-fusexmp_fh_SOURCES = fusexmp_fh.c
-null_SOURCES = null.c
-hello_SOURCES = hello.c
-
LDADD = ../lib/libfuse.la -lpthread
+fusexmp_fh_LDADD = ../lib/libfuse.la ../lib/libulockmgr.la -lpthread
diff --git a/example/fusexmp_fh.c b/example/fusexmp_fh.c
index 5ede6db..047ad09 100644
--- a/example/fusexmp_fh.c
+++ b/example/fusexmp_fh.c
@@ -11,6 +11,7 @@
#define _GNU_SOURCE
#include <fuse.h>
+#include <ulockmgr.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
@@ -400,6 +401,14 @@
}
#endif /* HAVE_SETXATTR */
+static int xmp_lock(const char *path, struct fuse_file_info *fi, int cmd,
+ struct flock *lock, uint64_t owner)
+{
+ (void) path;
+
+ return ulockmgr_op(fi->fh, cmd, lock, &owner, sizeof(owner));
+}
+
static struct fuse_operations xmp_oper = {
.getattr = xmp_getattr,
.fgetattr = xmp_fgetattr,
@@ -434,6 +443,7 @@
.listxattr = xmp_listxattr,
.removexattr= xmp_removexattr,
#endif
+ .lock = xmp_lock,
};
int main(int argc, char *argv[])
diff --git a/include/Makefile.am b/include/Makefile.am
index c786a0d..be2c592 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -11,6 +11,6 @@
fuse_lowlevel_compat.h \
fuse_opt.h
-include_HEADERS = old/fuse.h
+include_HEADERS = old/fuse.h ulockmgr.h
noinst_HEADERS = fuse_kernel.h
diff --git a/include/ulockmgr.h b/include/ulockmgr.h
new file mode 100644
index 0000000..4cd7b1c
--- /dev/null
+++ b/include/ulockmgr.h
@@ -0,0 +1,23 @@
+/*
+ libulockmgr: Userspace Lock Manager Library
+ Copyright (C) 2006 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU LGPL.
+ See the file COPYING.LIB.
+*/
+
+#include <stdint.h>
+#include <fcntl.h>
+
+/**
+ * Perform POSIX locking operation
+ *
+ * @param fd the file descriptor
+ * @param cmd the locking command (F_GETFL, F_SETLK or F_SETLKW)
+ * @param lock the lock parameters
+ * @param owner the lock owner ID cookie
+ * @param owner_len length of the lock owner ID cookie
+ * @return 0 on success -errno on error
+ */
+int ulockmgr_op(int fd, int cmd, struct flock *lock, const void *owner,
+ size_t owner_len);
diff --git a/kernel/configure.ac b/kernel/configure.ac
index c3c1f3f..910e125 100644
--- a/kernel/configure.ac
+++ b/kernel/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT(fuse-kernel, 2.6.0-pre3)
+AC_INIT(fuse-kernel, 2.6.0-rc1)
AC_CONFIG_HEADERS([config.h])
AC_PROG_INSTALL
diff --git a/kernel/file.c b/kernel/file.c
index 61eba56..e3a42c0 100644
--- a/kernel/file.c
+++ b/kernel/file.c
@@ -867,9 +867,32 @@
/* Unlock on close is handled by the flush method */
if (fl->fl_flags & FL_CLOSE)
return 0;
-#endif
req = fuse_get_req(fc);
+#else
+ /* If it's (possibly) unlock on close, don't fail the allocation */
+ if (fl->fl_type == F_UNLCK && fl->fl_start == 0 &&
+ fl->fl_end == OFFSET_MAX)
+ req = fuse_get_req_nofail(fc, file);
+ else {
+ /* Hack: add dummy lock, otherwise unlock on close is
+ optimized away */
+ struct file_lock **flp;
+ for (flp = &inode->i_flock;
+ *flp && !((*flp)->fl_flags & FL_POSIX);
+ flp = &(*flp)->fl_next);
+ if (!*flp) {
+ struct file_lock *dummy =
+ kmalloc(sizeof(struct file_lock), GFP_KERNEL);
+ if (!dummy)
+ return -ENOLCK;
+ locks_init_lock(dummy);
+ dummy->fl_flags |= FL_POSIX;
+ *flp = dummy;
+ }
+ req = fuse_get_req(fc);
+ }
+#endif
if (IS_ERR(req))
return PTR_ERR(req);
diff --git a/kernel/inode.c b/kernel/inode.c
index 0145045..475513b 100644
--- a/kernel/inode.c
+++ b/kernel/inode.c
@@ -83,6 +83,13 @@
struct fuse_inode *fi = get_fuse_inode(inode);
if (fi->forget_req)
fuse_request_free(fi->forget_req);
+#ifndef KERNEL_2_6_18_PLUS
+ if (inode->i_flock) {
+ WARN_ON(inode->i_flock->fl_next);
+ kfree(inode->i_flock);
+ inode->i_flock = NULL;
+ }
+#endif
kmem_cache_free(fuse_inode_cachep, inode);
}
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 5206493..87e323a 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,7 +1,7 @@
## Process this file with automake to produce Makefile.in
AM_CPPFLAGS = -I$(top_srcdir)/include -DFUSERMOUNT_DIR=\"$(bindir)\"
-lib_LTLIBRARIES = libfuse.la
+lib_LTLIBRARIES = libfuse.la libulockmgr.la
if BSD
mount_source = mount_bsd.c
@@ -27,4 +27,7 @@
libfuse_la_LDFLAGS = $(libfuse_libs) -version-number 2:6:0 \
-Wl,--version-script,$(srcdir)/fuse_versionscript
+libulockmgr_la_SOURCES = ulockmgr.c
+libulockmgr_la_LDFLAGS = -version-number 1:0:0
+
EXTRA_DIST = fuse_versionscript
diff --git a/lib/fuse.c b/lib/fuse.c
index a2f6bb1..92f21db 100644
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -34,6 +34,7 @@
#define FUSE_DEFAULT_INTR_SIGNAL SIGUSR1
#define FUSE_UNKNOWN_INO 0xffffffff
+#define OFFSET_MAX 0x7fffffffffffffffLL
struct fuse_config {
unsigned int uid;
@@ -76,6 +77,15 @@
int intr_installed;
};
+struct lock {
+ int type;
+ off_t start;
+ off_t end;
+ pid_t pid;
+ uint64_t owner;
+ struct lock *next;
+};
+
struct node {
struct node *name_next;
struct node *id_next;
@@ -91,6 +101,7 @@
struct timespec mtime;
off_t size;
int cache_valid;
+ struct lock *locks;
};
struct fuse_dirhandle {
@@ -1604,43 +1615,6 @@
reply_err(req, res);
}
-static void fuse_flush(fuse_req_t req, fuse_ino_t ino,
- struct fuse_file_info *fi, uint64_t owner)
-{
- struct fuse *f = req_fuse_prepare(req);
- char *path;
- int err;
-
- err = -ENOENT;
- pthread_rwlock_rdlock(&f->tree_lock);
- path = get_path(f, ino);
- if (path != NULL) {
- if (f->conf.debug) {
- printf("FLUSH[%llu]\n", (unsigned long long) fi->fh);
- fflush(stdout);
- }
- err = -ENOSYS;
- if (f->op.flush) {
- struct fuse_intr_data d;
- fuse_prepare_interrupt(f, req, &d);
- err = f->op.flush(path, fi);
- fuse_finish_interrupt(f, req, &d);
- }
- free(path);
- }
- if (f->op.lock) {
- struct flock lock;
- memset(&lock, 0, sizeof(lock));
- lock.l_type = F_UNLCK;
- lock.l_whence = SEEK_SET;
- fuse_do_lock(f, req, path, fi, F_SETLK, &lock, owner);
- if (err == -ENOSYS)
- err = 0;
- }
- pthread_rwlock_unlock(&f->tree_lock);
- reply_err(req, err);
-}
-
static void fuse_release(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi)
{
@@ -2162,6 +2136,167 @@
reply_err(req, err);
}
+static struct lock *locks_conflict(struct node *node, const struct lock *lock)
+{
+ struct lock *l;
+
+ for (l = node->locks; l; l = l->next)
+ if (l->owner != lock->owner &&
+ lock->start <= l->end && l->start <= lock->end &&
+ (l->type == F_WRLCK || lock->type == F_WRLCK))
+ break;
+
+ return l;
+}
+
+static void delete_lock(struct lock **lockp)
+{
+ struct lock *l = *lockp;
+ *lockp = l->next;
+ free(l);
+}
+
+static void insert_lock(struct lock **pos, struct lock *lock)
+{
+ lock->next = *pos;
+ *pos = lock;
+}
+
+static int locks_insert(struct node *node, struct lock *lock)
+{
+ struct lock **lp;
+ struct lock *newl1 = NULL;
+ struct lock *newl2 = NULL;
+
+ if (lock->type != F_UNLCK || lock->start != 0 || lock->end != OFFSET_MAX) {
+ newl1 = malloc(sizeof(struct lock));
+ newl2 = malloc(sizeof(struct lock));
+
+ if (!newl1 || !newl2) {
+ free(newl1);
+ free(newl2);
+ return -ENOLCK;
+ }
+ }
+
+ for (lp = &node->locks; *lp;) {
+ struct lock *l = *lp;
+ if (l->owner != lock->owner)
+ goto skip;
+
+ if (lock->type == l->type) {
+ if (l->end < lock->start - 1)
+ goto skip;
+ if (lock->end < l->start - 1)
+ break;
+ if (l->start <= lock->start && lock->end <= l->end)
+ goto out;
+ if (l->start < lock->start)
+ lock->start = l->start;
+ if (lock->end < l->end)
+ lock->end = l->end;
+ goto delete;
+ } else {
+ if (l->end < lock->start)
+ goto skip;
+ if (lock->end < l->start)
+ break;
+ if (lock->start <= l->start && l->end <= lock->end)
+ goto delete;
+ if (l->end <= lock->end) {
+ l->end = lock->start - 1;
+ goto skip;
+ }
+ if (lock->start <= l->start) {
+ l->start = lock->end + 1;
+ break;
+ }
+ *newl2 = *l;
+ newl2->start = lock->end + 1;
+ l->end = lock->start - 1;
+ insert_lock(&l->next, newl2);
+ newl2 = NULL;
+ }
+ skip:
+ lp = &l->next;
+ continue;
+
+ delete:
+ delete_lock(lp);
+ }
+ if (lock->type != F_UNLCK) {
+ *newl1 = *lock;
+ insert_lock(lp, newl1);
+ newl1 = NULL;
+ }
+out:
+ free(newl1);
+ free(newl2);
+ return 0;
+}
+
+static void flock_to_lock(struct flock *flock, struct lock *lock)
+{
+ memset(lock, 0, sizeof(struct lock));
+ lock->type = flock->l_type;
+ lock->start = flock->l_start;
+ lock->end = flock->l_len ? flock->l_start + flock->l_len - 1 : OFFSET_MAX;
+ lock->pid = flock->l_pid;
+}
+
+static void lock_to_flock(struct lock *lock, struct flock *flock)
+{
+ flock->l_type = lock->type;
+ flock->l_start = lock->start;
+ flock->l_len = (lock->end == OFFSET_MAX) ? 0 : lock->end - lock->start + 1;
+ flock->l_pid = lock->pid;
+}
+
+static void fuse_flush(fuse_req_t req, fuse_ino_t ino,
+ struct fuse_file_info *fi, uint64_t owner)
+{
+ struct fuse *f = req_fuse_prepare(req);
+ char *path;
+ int err;
+
+ err = -ENOENT;
+ pthread_rwlock_rdlock(&f->tree_lock);
+ path = get_path(f, ino);
+ if (path != NULL) {
+ if (f->conf.debug) {
+ printf("FLUSH[%llu]\n", (unsigned long long) fi->fh);
+ fflush(stdout);
+ }
+ err = -ENOSYS;
+ if (f->op.flush) {
+ struct fuse_intr_data d;
+ fuse_prepare_interrupt(f, req, &d);
+ err = f->op.flush(path, fi);
+ fuse_finish_interrupt(f, req, &d);
+ }
+ free(path);
+ }
+ if (f->op.lock) {
+ struct flock lock;
+ struct lock l;
+ memset(&lock, 0, sizeof(lock));
+ lock.l_type = F_UNLCK;
+ lock.l_whence = SEEK_SET;
+ fuse_do_lock(f, req, path, fi, F_SETLK, &lock, owner);
+ flock_to_lock(&lock, &l);
+ l.owner = owner;
+ pthread_mutex_lock(&f->lock);
+ locks_insert(get_node(f, ino), &l);
+ pthread_mutex_unlock(&f->lock);
+
+ /* if op.lock() is defined FLUSH is needed regardless of op.flush() */
+ if (err == -ENOSYS)
+ err = 0;
+ }
+ pthread_rwlock_unlock(&f->tree_lock);
+ reply_err(req, err);
+}
+
static int fuse_lock_common(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi, struct flock *lock,
uint64_t owner, int cmd)
@@ -2174,7 +2309,7 @@
pthread_rwlock_rdlock(&f->tree_lock);
path = get_path(f, ino);
if (path != NULL) {
- fuse_do_lock(f, req, path, fi, cmd, lock, owner);
+ err = fuse_do_lock(f, req, path, fi, cmd, lock, owner);
free(path);
}
pthread_rwlock_unlock(&f->tree_lock);
@@ -2185,7 +2320,23 @@
struct fuse_file_info *fi, struct flock *lock,
uint64_t owner)
{
- int err = fuse_lock_common(req, ino, fi, lock, owner, F_GETLK);
+ int err;
+ struct lock l;
+ struct lock *conflict;
+ struct fuse *f = req_fuse(req);
+
+ flock_to_lock(lock, &l);
+ l.owner = owner;
+ pthread_mutex_lock(&f->lock);
+ conflict = locks_conflict(get_node(f, ino), &l);
+ if (conflict)
+ lock_to_flock(conflict, lock);
+ pthread_mutex_unlock(&f->lock);
+ if (!conflict)
+ err = fuse_lock_common(req, ino, fi, lock, owner, F_GETLK);
+ else
+ err = 0;
+
if (!err)
fuse_reply_lock(req, lock);
else
@@ -2196,8 +2347,18 @@
struct fuse_file_info *fi, struct flock *lock,
uint64_t owner, int sleep)
{
- reply_err(req, fuse_lock_common(req, ino, fi, lock, owner,
- sleep ? F_SETLKW : F_SETLK));
+ int err = fuse_lock_common(req, ino, fi, lock, owner,
+ sleep ? F_SETLKW : F_SETLK);
+ if (!err) {
+ struct fuse *f = req_fuse(req);
+ struct lock l;
+ flock_to_lock(lock, &l);
+ l.owner = owner;
+ pthread_mutex_lock(&f->lock);
+ locks_insert(get_node(f, ino), &l);
+ pthread_mutex_unlock(&f->lock);
+ }
+ reply_err(req, err);
}
static struct fuse_lowlevel_ops fuse_path_ops = {
@@ -2418,8 +2579,7 @@
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_handler = fuse_intr_sighandler;
- sigemptyset(&(sa.sa_mask));
- sa.sa_flags = 0;
+ sigemptyset(&sa.sa_mask);
if (sigaction(signum, &sa, NULL) == -1) {
perror("fuse: cannot set interrupt signal handler");
diff --git a/lib/ulockmgr.c b/lib/ulockmgr.c
new file mode 100644
index 0000000..795fc41
--- /dev/null
+++ b/lib/ulockmgr.c
@@ -0,0 +1,402 @@
+/*
+ libulockmgr: Userspace Lock Manager Library
+ Copyright (C) 2006 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU LGPL.
+ See the file COPYING.LIB
+*/
+
+/* #define DEBUG 1 */
+
+#include "ulockmgr.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+
+struct message {
+ int intr;
+ pthread_t thr;
+ int cmd;
+ int fd;
+ struct flock lock;
+ int error;
+};
+
+struct fd_store {
+ struct fd_store *next;
+ int fd;
+ int finished;
+};
+
+struct owner {
+ struct owner *next;
+ struct owner *prev;
+ struct fd_store *fds;
+ void *id;
+ size_t id_len;
+ int cfd;
+};
+
+static pthread_mutex_t ulockmgr_lock;
+static int ulockmgr_cfd = -1;
+static struct owner owner_list = { .next = &owner_list, .prev = &owner_list };
+
+#define MAX_SEND_FDS 2
+
+static void list_del_owner(struct owner *owner)
+{
+ struct owner *prev = owner->prev;
+ struct owner *next = owner->next;
+ prev->next = next;
+ next->prev = prev;
+}
+
+static void list_add_owner(struct owner *owner, struct owner *next)
+{
+ struct owner *prev = next->prev;
+ owner->next = next;
+ owner->prev = prev;
+ prev->next = owner;
+ next->prev = owner;
+}
+
+static int ulockmgr_send_message(int sock, void *buf, size_t buflen,
+ int *fdp, int numfds)
+{
+ struct msghdr msg;
+ struct cmsghdr *p_cmsg;
+ struct iovec vec;
+ char cmsgbuf[CMSG_SPACE(sizeof(int) * MAX_SEND_FDS)];
+ int res;
+
+ assert(numfds <= MAX_SEND_FDS);
+ msg.msg_control = cmsgbuf;
+ msg.msg_controllen = sizeof(cmsgbuf);
+ p_cmsg = CMSG_FIRSTHDR(&msg);
+ p_cmsg->cmsg_level = SOL_SOCKET;
+ p_cmsg->cmsg_type = SCM_RIGHTS;
+ p_cmsg->cmsg_len = CMSG_LEN(sizeof(int) * numfds);
+ memcpy(CMSG_DATA(p_cmsg), fdp, sizeof(int) * numfds);
+ msg.msg_controllen = p_cmsg->cmsg_len;
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_iov = &vec;
+ msg.msg_iovlen = 1;
+ msg.msg_flags = 0;
+ vec.iov_base = buf;
+ vec.iov_len = buflen;
+ res = sendmsg(sock, &msg, MSG_NOSIGNAL);
+ if (res == -1) {
+ perror("libulockmgr: sendmsg");
+ return -1;
+ }
+ if ((size_t) res != buflen) {
+ fprintf(stderr, "libulockmgr: sendmsg short\n");
+ return -1;
+ }
+ return 0;
+}
+
+static int ulockmgr_start_daemon(void)
+{
+ int sv[2];
+ int res;
+ char tmp[64];
+
+ res = socketpair(AF_UNIX, SOCK_STREAM, 0, sv);
+ if (res == -1) {
+ perror("libulockmgr: socketpair");
+ return -1;
+ }
+ snprintf(tmp, sizeof(tmp), "exec ulockmgr_server %i", sv[0]);
+ res = system(tmp);
+ close(sv[0]);
+ if (res == -1 || !WIFEXITED(res) || WEXITSTATUS(res) != 0) {
+ close(sv[1]);
+ return -1;
+ }
+ ulockmgr_cfd = sv[1];
+ return 0;
+}
+
+static struct owner *ulockmgr_new_owner(const void *id, size_t id_len)
+{
+ int sv[2];
+ int res;
+ char c = 'm';
+ struct owner *o;
+
+ if (ulockmgr_cfd == -1 && ulockmgr_start_daemon() == -1)
+ return NULL;
+
+ o = calloc(1, sizeof(struct owner) + id_len);
+ if (!o) {
+ fprintf(stderr, "libulockmgr: failed to allocate memory\n");
+ return NULL;
+ }
+ o->id = o + 1;
+ o->id_len = id_len;
+ res = socketpair(AF_UNIX, SOCK_STREAM, 0, sv);
+ if (res == -1) {
+ perror("libulockmgr: socketpair");
+ goto out_free;
+ }
+ res = ulockmgr_send_message(ulockmgr_cfd, &c, sizeof(c), &sv[0], 1);
+ close(sv[0]);
+ if (res == -1) {
+ close(ulockmgr_cfd);
+ ulockmgr_cfd = -1;
+ goto out_close;
+ }
+
+ o->cfd = sv[1];
+ memcpy(o->id, id, id_len);
+ list_add_owner(o, &owner_list);
+
+ return o;
+
+ out_close:
+ close(sv[1]);
+ out_free:
+ free(o);
+ return NULL;
+}
+
+static int ulockmgr_send_request(struct message *msg, const void *id,
+ size_t id_len)
+{
+ int sv[2];
+ int cfd;
+ struct owner *o;
+ struct fd_store *f;
+ int fd = msg->fd;
+ int cmd = msg->cmd;
+ int res;
+ int unlockall = (cmd == F_SETLK && msg->lock.l_type == F_UNLCK &&
+ msg->lock.l_start == 0 && msg->lock.l_len == 0);
+
+ for (o = owner_list.next; o != &owner_list; o = o->next)
+ if (o->id_len == id_len && memcmp(o->id, id, id_len) == 0)
+ break;
+
+ if (o == &owner_list)
+ o = NULL;
+
+ if (!o && cmd != F_GETLK && msg->lock.l_type != F_UNLCK)
+ o = ulockmgr_new_owner(id, id_len);
+
+ if (!o) {
+ if (cmd == F_GETLK) {
+ res = fcntl(msg->fd, F_GETLK, &msg->lock);
+ return (res == -1) ? -errno : 0;
+ } else if (msg->lock.l_type == F_UNLCK)
+ return 0;
+ else
+ return -ENOLCK;
+ }
+
+ f = calloc(1, sizeof(struct fd_store));
+ if (!f) {
+ fprintf(stderr, "libulockmgr: failed to allocate memory\n");
+ return -ENOLCK;
+ }
+
+ res = socketpair(AF_UNIX, SOCK_STREAM, 0, sv);
+ if (res == -1) {
+ perror("libulockmgr: socketpair");
+ free(f);
+ return -ENOLCK;
+ }
+
+ cfd = sv[1];
+ sv[1] = msg->fd;
+ res = ulockmgr_send_message(o->cfd, msg, sizeof(struct message), sv, 2);
+ close(sv[0]);
+ if (res == -1) {
+ free(f);
+ close(cfd);
+ return -EIO;
+ }
+
+ f->fd = msg->fd;
+ f->next = o->fds;
+ o->fds = f;
+
+ res = recv(cfd, msg, sizeof(struct message), MSG_WAITALL);
+ if (res == -1) {
+ perror("libulockmgr: recv");
+ msg->error = EIO;
+ } else if (res != sizeof(struct message)) {
+ fprintf(stderr, "libulockmgr: recv short\n");
+ msg->error = EIO;
+ } else if (cmd == F_SETLKW && msg->error == EAGAIN) {
+ pthread_mutex_unlock(&ulockmgr_lock);
+ while (1) {
+ sigset_t old;
+ sigset_t unblock;
+ int errno_save;
+
+ sigemptyset(&unblock);
+ sigaddset(&unblock, SIGUSR1);
+ pthread_sigmask(SIG_UNBLOCK, &unblock, &old);
+ res = recv(cfd, msg, sizeof(struct message), MSG_WAITALL);
+ errno_save = errno;
+ pthread_sigmask(SIG_SETMASK, &old, NULL);
+ if (res == sizeof(struct message))
+ break;
+ else if (res >= 0) {
+ fprintf(stderr, "libulockmgr: recv short\n");
+ msg->error = EIO;
+ break;
+ } else if (errno_save != EINTR) {
+ errno = errno_save;
+ perror("libulockmgr: recv");
+ msg->error = EIO;
+ break;
+ }
+ msg->intr = 1;
+ res = send(o->cfd, msg, sizeof(struct message), MSG_NOSIGNAL);
+ if (res == -1) {
+ perror("libulockmgr: send");
+ msg->error = EIO;
+ break;
+ }
+ if (res != sizeof(struct message)) {
+ fprintf(stderr, "libulockmgr: send short\n");
+ msg->error = EIO;
+ break;
+ }
+ }
+ pthread_mutex_lock(&ulockmgr_lock);
+
+ }
+
+ f->finished = 1;
+ close(cfd);
+ if (unlockall) {
+ struct fd_store **fp;
+
+ for (fp = &o->fds; *fp;) {
+ f = *fp;
+ if (f->fd == fd && f->finished) {
+ *fp = f->next;
+ free(f);
+ } else
+ fp = &f->next;
+ }
+ if (!o->fds) {
+ list_del_owner(o);
+ close(o->cfd);
+ free(o);
+ }
+ /* Force OK on unlock-all, since it _will_ succeed once the
+ owner is deleted */
+ msg->error = 0;
+ }
+
+ return -msg->error;
+}
+
+#ifdef DEBUG
+static uint32_t owner_hash(const unsigned char *id, size_t id_len)
+{
+ uint32_t h = 0;
+ size_t i;
+ for (i = 0; i < id_len; i++)
+ h = ((h << 8) | (h >> 24)) ^ id[i];
+
+ return h;
+}
+#endif
+
+static int ulockmgr_canonicalize(int fd, struct flock *lock)
+{
+ off_t offset;
+ if (lock->l_whence == SEEK_CUR) {
+ offset = lseek(fd, 0, SEEK_CUR);
+ if (offset == (off_t) -1)
+ return -errno;
+ } else if (lock->l_whence == SEEK_END) {
+ struct stat stbuf;
+ int res = fstat(fd, &stbuf);
+ if (res == -1)
+ return -errno;
+
+ offset = stbuf.st_size;
+ } else
+ offset = 0;
+
+ lock->l_whence = SEEK_SET;
+ lock->l_start += offset;
+
+ if (lock->l_start < 0)
+ return -EINVAL;
+
+ if (lock->l_len < 0) {
+ lock->l_start += lock->l_len;
+ if (lock->l_start < 0)
+ return -EINVAL;
+ lock->l_len = -lock->l_len;
+ }
+ if (lock->l_len && lock->l_start + lock->l_len - 1 < 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+int ulockmgr_op(int fd, int cmd, struct flock *lock, const void *owner,
+ size_t owner_len)
+{
+ int err;
+ struct message msg;
+ sigset_t old;
+ sigset_t block;
+
+ if (cmd != F_GETLK && cmd != F_SETLK && cmd != F_SETLKW)
+ return -EINVAL;
+
+ if (lock->l_whence != SEEK_SET && lock->l_whence != SEEK_CUR &&
+ lock->l_whence != SEEK_END)
+ return -EINVAL;
+
+#ifdef DEBUG
+ fprintf(stderr, "libulockmgr: %i %i %i %lli %lli own: 0x%08x\n",
+ cmd, lock->l_type, lock->l_whence, lock->l_start, lock->l_len,
+ owner_hash(owner, owner_len));
+#endif
+
+ /* Unlock should never block anyway */
+ if (cmd == F_SETLKW && lock->l_type == F_UNLCK)
+ cmd = F_SETLK;
+
+ memset(&msg, 0, sizeof(struct message));
+ msg.cmd = cmd;
+ msg.fd = fd;
+ msg.lock = *lock;
+ err = ulockmgr_canonicalize(fd, &msg.lock);
+ if (err)
+ return err;
+
+ sigemptyset(&block);
+ sigaddset(&block, SIGUSR1);
+ pthread_sigmask(SIG_BLOCK, &block, &old);
+ pthread_mutex_lock(&ulockmgr_lock);
+ err = ulockmgr_send_request(&msg, owner, owner_len);
+ pthread_mutex_unlock(&ulockmgr_lock);
+ pthread_sigmask(SIG_SETMASK, &old, NULL);
+ if (!err && cmd == F_GETLK) {
+ if (msg.lock.l_type == F_UNLCK)
+ lock->l_type = F_UNLCK;
+ else
+ *lock = msg.lock;
+ }
+
+ return err;
+}
diff --git a/util/.cvsignore b/util/.cvsignore
index 87461c8..d7a4699 100644
--- a/util/.cvsignore
+++ b/util/.cvsignore
@@ -3,4 +3,5 @@
.deps
.libs
fusermount
+ulockmgr_server
fuse_ioslave
diff --git a/util/Makefile.am b/util/Makefile.am
index c07440a..8e8db2a 100644
--- a/util/Makefile.am
+++ b/util/Makefile.am
@@ -1,9 +1,12 @@
## Process this file with automake to produce Makefile.in
-bin_PROGRAMS = fusermount
+bin_PROGRAMS = fusermount ulockmgr_server
fusermount_SOURCES = fusermount.c
+ulockmgr_server_SOURCES = ulockmgr_server.c
+ulockmgr_server_LDFLAGS = -pthread
+
install-exec-hook:
-chown root $(DESTDIR)$(bindir)/fusermount
-chmod u+s $(DESTDIR)$(bindir)/fusermount
diff --git a/util/ulockmgr_server.c b/util/ulockmgr_server.c
new file mode 100644
index 0000000..a2d6863
--- /dev/null
+++ b/util/ulockmgr_server.c
@@ -0,0 +1,347 @@
+/*
+ ulockmgr_server: Userspace Lock Manager Server
+ Copyright (C) 2006 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/* #define DEBUG 1 */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+
+struct message {
+ int intr;
+ pthread_t thr;
+ int cmd;
+ int fd;
+ struct flock lock;
+ int error;
+};
+
+struct fd_store {
+ struct fd_store *next;
+ int fd;
+ int origfd;
+ int finished;
+};
+
+struct owner {
+ struct fd_store *fds;
+ pthread_mutex_t lock;
+};
+
+struct req_data {
+ struct owner *o;
+ int cfd;
+ struct fd_store *f;
+ struct message msg;
+};
+
+#define MAX_SEND_FDS 2
+
+static int receive_message(int sock, void *buf, size_t buflen, int *fdp,
+ int numfds)
+{
+ struct msghdr msg;
+ struct iovec iov;
+ char ccmsg[CMSG_SPACE(sizeof(int)) * MAX_SEND_FDS];
+ struct cmsghdr *cmsg;
+ int res;
+
+ assert(numfds <= MAX_SEND_FDS);
+ iov.iov_base = buf;
+ iov.iov_len = buflen;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = ccmsg;
+ msg.msg_controllen = sizeof(ccmsg);
+
+ res = recvmsg(sock, &msg, MSG_WAITALL);
+ if (!res)
+ return 0;
+ if (res == -1) {
+ perror("ulockmgr_server: recvmsg");
+ return -1;
+ }
+ if ((size_t) res != buflen) {
+ fprintf(stderr, "ulockmgr_server: short message received\n");
+ return -1;
+ }
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (cmsg) {
+ if (!cmsg->cmsg_type == SCM_RIGHTS) {
+ fprintf(stderr, "ulockmgr_server: unknown control message %d\n",
+ cmsg->cmsg_type);
+ return -1;
+ }
+ memcpy(fdp, CMSG_DATA(cmsg), sizeof(int) * numfds);
+ }
+ return res;
+}
+
+static int closefrom(int minfd)
+{
+ DIR *dir = opendir("/proc/self/fd");
+ if (dir) {
+ int dfd = dirfd(dir);
+ struct dirent *ent;
+ while ((ent = readdir(dir))) {
+ char *end;
+ int fd = strtol(ent->d_name, &end, 10);
+ if (ent->d_name[0] && !end[0] && fd >= minfd && fd != dfd)
+ close(fd);
+ }
+ closedir(dir);
+ }
+ return 0;
+}
+
+static void send_reply(int cfd, struct message *msg)
+{
+ int res = send(cfd, msg, sizeof(struct message), MSG_NOSIGNAL);
+ if (res == -1)
+ perror("ulockmgr_server: sending reply");
+#ifdef DEBUG
+ fprintf(stderr, "ulockmgr_server: error: %i\n", msg->error);
+#endif
+}
+
+static void *process_request(void *d_)
+{
+ struct req_data *d = d_;
+ int res;
+
+ assert(d->msg.cmd == F_SETLKW);
+ res = fcntl(d->f->fd, F_SETLK, &d->msg.lock);
+ if (res == -1 && errno == EAGAIN) {
+ d->msg.error = EAGAIN;
+ d->msg.thr = pthread_self();
+ send_reply(d->cfd, &d->msg);
+ res = fcntl(d->f->fd, F_SETLKW, &d->msg.lock);
+ }
+ d->msg.error = (res == -1) ? errno : 0;
+ pthread_mutex_lock(&d->o->lock);
+ d->f->finished = 1;
+ pthread_mutex_unlock(&d->o->lock);
+ send_reply(d->cfd, &d->msg);
+ close(d->cfd);
+ free(d);
+
+ return NULL;
+}
+
+static void process_message(struct owner *o, struct message *msg, int cfd,
+ int fd)
+{
+ struct fd_store *f;
+ struct req_data *d;
+ pthread_t tid;
+ int res;
+
+#ifdef DEBUG
+ fprintf(stderr, "ulockmgr_server: %i %i %i %lli %lli\n",
+ msg->cmd, msg->lock.l_type, msg->lock.l_whence, msg->lock.l_start,
+ msg->lock.l_len);
+#endif
+
+ if (msg->cmd == F_SETLK && msg->lock.l_type == F_UNLCK &&
+ msg->lock.l_start == 0 && msg->lock.l_len == 0) {
+ struct fd_store **fp;
+
+ for (fp = &o->fds; *fp;) {
+ struct fd_store *f = *fp;
+ if (f->origfd == msg->fd && f->finished) {
+ close(f->fd);
+ *fp = f->next;
+ free(f);
+ } else
+ fp = &f->next;
+ }
+ close(fd);
+
+ msg->error = 0;
+ send_reply(cfd, msg);
+ close(cfd);
+ return;
+ }
+
+ f = malloc(sizeof(struct fd_store));
+ if (!f) {
+ msg->error = ENOLCK;
+ send_reply(cfd, msg);
+ close(cfd);
+ return;
+ }
+
+ f->fd = fd;
+ f->origfd = msg->fd;
+
+ if (msg->cmd == F_GETLK || msg->cmd == F_SETLK ||
+ msg->lock.l_type == F_UNLCK) {
+ res = fcntl(f->fd, msg->cmd, &msg->lock);
+ msg->error = (res == -1) ? errno : 0;
+ send_reply(cfd, msg);
+ close(cfd);
+ f->next = o->fds;
+ o->fds = f;
+ f->finished = 1;
+ return;
+ }
+
+ d = malloc(sizeof(struct req_data));
+ if (!d) {
+ msg->error = ENOLCK;
+ send_reply(cfd, msg);
+ close(cfd);
+ free(f);
+ return;
+ }
+
+ d->o = o;
+ d->cfd = cfd;
+ d->f = f;
+ d->msg = *msg;
+ res = pthread_create(&tid, NULL, process_request, d);
+ if (res) {
+ msg->error = ENOLCK;
+ send_reply(cfd, msg);
+ close(cfd);
+ free(d);
+ free(f);
+ return;
+ }
+
+ f->next = o->fds;
+ o->fds = f;
+ pthread_detach(tid);
+}
+
+static void sigusr1_handler(int sig)
+{
+ (void) sig;
+ /* Nothing to do */
+}
+
+static void process_owner(int cfd)
+{
+ struct owner o;
+ struct sigaction sa;
+
+ memset(&sa, 0, sizeof(struct sigaction));
+ sa.sa_handler = sigusr1_handler;
+ sigemptyset(&sa.sa_mask);
+
+ if (sigaction(SIGUSR1, &sa, NULL) == -1) {
+ perror("ulockmgr_server: cannot set sigusr1 signal handler");
+ exit(1);
+ }
+
+ memset(&o, 0, sizeof(struct owner));
+ pthread_mutex_init(&o.lock, NULL);
+ while (1) {
+ struct message msg;
+ int rfds[2];
+ int res;
+
+ res = receive_message(cfd, &msg, sizeof(msg), rfds, 2);
+ if (!res)
+ break;
+ if (res == -1)
+ exit(1);
+
+ if (msg.intr)
+ pthread_kill(msg.thr, SIGUSR1);
+ else {
+ pthread_mutex_lock(&o.lock);
+ process_message(&o, &msg, rfds[0], rfds[1]);
+ pthread_mutex_unlock(&o.lock);
+ }
+ }
+ if (o.fds)
+ fprintf(stderr, "ulockmgr_server: open file descriptors on exit\n");
+}
+
+int main(int argc, char *argv[])
+{
+ int nullfd;
+ char *end;
+ int cfd;
+ sigset_t empty;
+
+ if (argc != 2 || !argv[1][0])
+ goto out_inval;
+
+ cfd = strtol(argv[1], &end, 10);
+ if (*end)
+ goto out_inval;
+
+ if (daemon(0, 1) == -1) {
+ perror("ulockmgr_server: daemon");
+ exit(1);
+ }
+
+ sigemptyset(&empty);
+ sigprocmask(SIG_SETMASK, &empty, NULL);
+
+ if (dup2(cfd, 4) == -1) {
+ perror("ulockmgr_server: dup2");
+ exit(1);
+ }
+ cfd = 4;
+ nullfd = open("/dev/null", O_RDWR);
+ dup2(nullfd, 0);
+ dup2(nullfd, 1);
+ close(3);
+ closefrom(5);
+ while (1) {
+ char c;
+ int sock;
+ int pid;
+ int res = receive_message(cfd, &c, sizeof(c), &sock, 1);
+ if (!res)
+ break;
+ if (res == -1)
+ exit(1);
+
+ pid = fork();
+ if (pid == -1) {
+ perror("ulockmgr_server: fork");
+ close(sock);
+ continue;
+ }
+ if (pid == 0) {
+ close(cfd);
+ pid = fork();
+ if (pid == -1) {
+ perror("ulockmgr_server: fork");
+ _exit(1);
+ }
+ if (pid == 0)
+ process_owner(sock);
+ _exit(0);
+ }
+ waitpid(pid, NULL, 0);
+ close(sock);
+ }
+ return 0;
+
+ out_inval:
+ fprintf(stderr, "%s should be started by libulockmgr\n", argv[0]);
+ return 1;
+}