#include <fcntl.h>
struct relay_index_file {
- bool suspendable;
- union {
- /* Suspendable. */
- struct fs_handle *handle;
- /* Unsuspendable. */
- int fd;
- } u;
+ struct fs_handle *handle;
uint32_t major;
uint32_t minor;
uint32_t element_len;
struct urcu_ref ref;
};
+/*
+ * This unlink wrapper allows the fd_tracker to check if any other
+ * fs_handle references the index before unlinking it. If the relay holds
+ * this file open, it is essential to unlink it through an fs_handle as this
+ * will delay the actual unlink() until all handles have released this file.
+ *
+ * The file is renamed and unlinked once the last handle to its inode has been
+ * released.
+ */
+static
+int unlink_through_handle(const char *path)
+{
+ int ret = 0, close_ret;
+ struct fs_handle *handle;
+ /*
+ * Since this operation is only performed to perform the unlink
+ * through the fs_handle and fd-tracker system, the flag is opened
+ * without the O_CREAT. There is no need to perform the unlink if
+ * the file doesn't already exist.
+ */
+ int flags = O_RDONLY;
+
+ DBG("Unlinking index at %s through a filesystem handle", path);
+ handle = fd_tracker_open_fs_handle(the_fd_tracker, path, flags, NULL);
+ if (!handle) {
+ /* There is nothing to do. */
+ DBG("File %s does not exist, ignoring unlink", path);
+ goto end;
+ }
+
+ ret = fs_handle_unlink(handle);
+ close_ret = fs_handle_close(handle);
+ if (close_ret) {
+ ERR("Failed to close handle after performing an unlink operation on a filesystem handle");
+ }
+end:
+ if (ret) {
+ DBG("Unlinking index at %s failed with error code %i", path, ret);
+ }
+ return ret;
+}
+
/*
* Create the index file associated with a trace file.
*
goto error;
}
- /*
- * The receiving end of the relay daemon is not expected to try
- * to append to an index file. It is thus safe to create it as
- * suspendable.
- */
- index_file->suspendable = true;
-
ret = snprintf(idx_dir_path, sizeof(idx_dir_path), "%s/" DEFAULT_INDEX_DIR,
path_name);
if (ret < 0) {
* stays valid even if we re-create a new file with the
* same name afterwards.
*/
- unlink(idx_file_path);
- if (ret < 0 && errno != ENOENT) {
- PERROR("Failed to unlink index file");
+ ret = unlink_through_handle(idx_file_path);
+ if (ret < 0) {
goto error;
}
if (!fs_handle) {
goto error;
}
- index_file->u.handle = fs_handle;
+ index_file->handle = fs_handle;
fd = fs_handle_get_fd(fs_handle);
if (fd < 0) {
return NULL;
}
-static
-int open_file(void *data, int *out_fd)
-{
- int ret;
- const char *path = data;
-
- ret = open(path, O_RDONLY);
- if (ret < 0) {
- goto end;
- }
- *out_fd = ret;
- ret = 0;
-end:
- return ret;
-}
-
struct relay_index_file *relay_index_file_open(const char *path_name,
const char *channel_name, uint64_t tracefile_count,
uint64_t tracefile_count_current)
{
struct relay_index_file *index_file;
- int ret, fd;
+ int ret, fd = -1;
ssize_t read_len;
char fullpath[PATH_MAX];
- char *path_param = fullpath;
struct ctf_packet_index_file_hdr hdr;
uint32_t major, minor, element_len;
+ int flags = O_RDONLY;
+ struct fs_handle *handle = NULL;
assert(path_name);
assert(channel_name);
goto error;
}
- index_file->suspendable = false;
-
if (tracefile_count > 0) {
ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%"
PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name,
goto error;
}
- DBG("Index opening file %s in read only", fullpath);
- ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &fd,
- (const char **) &path_param, 1,
- open_file, (void *) fullpath);
- if (ret < 0) {
+ DBG("Index opening file %s in read only mode", fullpath);
+ handle = fd_tracker_open_fs_handle(the_fd_tracker, fullpath, flags,
+ NULL);
+ if (!handle) {
PERROR("Failed to open index file at %s", fullpath);
goto error;
}
+ fd = fs_handle_get_fd(handle);
+ if (fd < 0) {
+ PERROR("Failed to get fd of index file at %s", fullpath);
+ goto error;
+ }
+
read_len = lttng_read(fd, &hdr, sizeof(hdr));
if (read_len < 0) {
PERROR("Failed to read index header");
goto error_close;
}
- index_file->u.fd = fd;
+ fs_handle_put_fd(handle);
+ index_file->handle = handle;
index_file->major = major;
index_file->minor = minor;
index_file->element_len = element_len;
return index_file;
error_close:
- ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &fd,
- 1, fd_tracker_util_close_fd, NULL);
+ if (fd >= 0) {
+ fs_handle_put_fd(handle);
+ }
+ ret = fs_handle_close(handle);
if (ret < 0) {
- PERROR("Failed to close index fd %d", fd);
+ PERROR("Failed to close index filesystem handle to %s",
+ fullpath);
}
error:
assert(index_file);
assert(element);
- fd = index_file->suspendable ?
- fs_handle_get_fd(index_file->u.handle) :
- index_file->u.fd;
+ fd = fs_handle_get_fd(index_file->handle);
if (fd < 0) {
ret = fd;
goto end;
}
ret = 0;
- if (index_file->suspendable) {
- fs_handle_put_fd(index_file->u.handle);
- }
+ fs_handle_put_fd(index_file->handle);
end:
return ret;
}
assert(index_file);
assert(element);
- fd = index_file->suspendable ?
- fs_handle_get_fd(index_file->u.handle) :
- index_file->u.fd;
+ fd = fs_handle_get_fd(index_file->handle);
if (fd < 0) {
ret = fd;
goto end;
}
ret = 0;
- if (index_file->suspendable) {
- fs_handle_put_fd(index_file->u.handle);
- }
+ fs_handle_put_fd(index_file->handle);
end:
return ret;
}
int fd, ret = 0;
off_t lseek_ret;
- fd = index_file->suspendable ?
- fs_handle_get_fd(index_file->u.handle) :
- index_file->u.fd;
+ fd = fs_handle_get_fd(index_file->handle);
if (fd < 0) {
ret = fd;
goto end;
ret = lseek_ret;
}
- if (index_file->suspendable) {
- fs_handle_put_fd(index_file->u.handle);
- }
+ fs_handle_put_fd(index_file->handle);
end:
return ret;
}
struct relay_index_file *index_file = caa_container_of(ref,
struct relay_index_file, ref);
- if (index_file->suspendable) {
- ret = fs_handle_close(index_file->u.handle);
- } else {
- ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &index_file->u.fd,
- 1, fd_tracker_util_close_fd, NULL);
- }
+ ret = fs_handle_close(index_file->handle);
if (ret < 0) {
PERROR("Failed to close index file");
}
projects / lttng-tools.git / commitdiff
