/*
- * Copyright (C) 2018, 2020 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2018-2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <urcu.h>
const char *path;
pthread_mutex_lock(&handle->lock);
- lttng_inode_get_location(handle->inode, NULL, &path);
+ lttng_inode_borrow_location(handle->inode, NULL, &path);
if (handle->fd >= 0) {
DBG_NO_LOC(" %s [active, fd %d%s]", path, handle->fd,
const struct lttng_directory_handle *node_directory_handle;
pthread_mutex_lock(&handle->lock);
- lttng_inode_get_location(handle->inode, &node_directory_handle, &path);
+ lttng_inode_borrow_location(
+ handle->inode, &node_directory_handle, &path);
assert(handle->fd >= 0);
if (handle->in_use) {
/* This handle can't be suspended as it is currently in use. */
const char *path;
const struct lttng_directory_handle *node_directory_handle;
- lttng_inode_get_location(handle->inode, &node_directory_handle, &path);
+ lttng_inode_borrow_location(
+ handle->inode, &node_directory_handle, &path);
assert(handle->fd == -1);
assert(path);
return ret;
}
+LTTNG_HIDDEN
struct fd_tracker *fd_tracker_create(const char *unlinked_file_path,
unsigned int capacity)
{
return NULL;
}
+LTTNG_HIDDEN
void fd_tracker_log(struct fd_tracker *tracker)
{
struct fs_handle_tracked *handle;
pthread_mutex_unlock(&tracker->lock);
}
+LTTNG_HIDDEN
int fd_tracker_destroy(struct fd_tracker *tracker)
{
int ret = 0;
+ if (!tracker) {
+ goto end;
+ }
/*
* Refuse to destroy the tracker as fs_handles may still old
* weak references to the tracker.
return ret;
}
+LTTNG_HIDDEN
struct fs_handle *fd_tracker_open_fs_handle(struct fd_tracker *tracker,
struct lttng_directory_handle *directory,
const char *path,
return left_to_close ? -EMFILE : 0;
}
+LTTNG_HIDDEN
int fd_tracker_open_unsuspendable_fd(struct fd_tracker *tracker,
int *out_fds,
const char **names,
} else {
/*
* There are not enough active suspendable file
- * descriptors to open a new fd and still accomodate the
+ * descriptors to open a new fd and still accommodates the
* tracker's capacity.
*/
WARN("Cannot open unsuspendable fd, too many unsuspendable file descriptors are opened (%u)",
goto end_unlock;
}
+LTTNG_HIDDEN
int fd_tracker_close_unsuspendable_fd(struct fd_tracker *tracker,
int *fds_in,
unsigned int fd_count,
const char *path = NULL;
struct fs_handle_tracked *handle =
container_of(_handle, struct fs_handle_tracked, parent);
+ struct lttng_directory_handle *inode_directory_handle = NULL;
if (!handle) {
ret = -EINVAL;
pthread_mutex_lock(&handle->tracker->lock);
pthread_mutex_lock(&handle->lock);
if (handle->inode) {
- lttng_inode_get_location(handle->inode, NULL, &path);
+ lttng_inode_borrow_location(handle->inode, NULL, &path);
+ /*
+ * Here a reference to the inode's directory handle is acquired
+ * to prevent the last reference to it from being released while
+ * the tracker's lock is taken.
+ *
+ * If this wasn't done, the directory handle could attempt to
+ * close its underlying directory file descriptor, which would
+ * attempt to lock the tracker's lock, resulting in a deadlock.
+ *
+ * Since a new reference to the directory handle is taken within
+ * the scope of this function, it is not possible for the last
+ * reference to the inode's location directory handle to be
+ * released during the call to lttng_inode_put().
+ *
+ * We wait until the tracker's lock is released to release the
+ * reference. Hence, the call to the tracker is delayed just
+ * enough to not attempt to recursively acquire the tracker's
+ * lock twice.
+ */
+ inode_directory_handle =
+ lttng_inode_get_location_directory_handle(
+ handle->inode);
}
fd_tracker_untrack(handle->tracker, handle);
if (handle->fd >= 0) {
* isn't much the user can do about it.
*/
if (close(handle->fd)) {
- PERROR("Failed to close the file descritptor (%d) of fs handle to %s, close() returned",
+ PERROR("Failed to close the file descriptor (%d) of fs handle to %s, close() returned",
handle->fd, path ? path : "Unknown");
}
handle->fd = -1;
pthread_mutex_destroy(&handle->lock);
pthread_mutex_unlock(&handle->tracker->lock);
free(handle);
+ lttng_directory_handle_put(inode_directory_handle);
end:
return ret;
}