2 * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 * SPDX-License-Identifier: LGPL-2.1-only
11 #include <common/macros.hpp>
18 * Marks the handle as the most recently used and marks the 'fd' as
19 * "in-use". This prevents the tracker from recycling the underlying
20 * file descriptor while it is actively being used by a thread.
22 * Don't forget that the tracker may be initiating an fd 'suspension'
23 * from another thread as the need to free an fd slot may arise from any
24 * thread within the daemon.
26 * Note that a restorable fd should never be held for longer than
27 * strictly necessary (e.g. the duration of a syscall()).
29 * Returns the fd on success, otherwise a negative value may be returned
30 * if the restoration of the fd failed.
32 int fs_handle_get_fd(struct fs_handle *handle);
35 * Used by the caller to signal that it is no longer using the underlying fd and
36 * that it may be safely suspended.
38 void fs_handle_put_fd(struct fs_handle *handle);
41 * Unlink the file associated to an fs_handle. Note that the unlink
42 * operation will not be performed immediately. It will only be performed
43 * once all references to the underlying file (through other fs_handle objects)
46 * However, note that the file will be renamed so as to provide the observable
47 * effect of an unlink(), that is removing a name from the filesystem.
49 * Returns 0 on success, otherwise a negative value will be returned
50 * if the operation failed.
52 int fs_handle_unlink(struct fs_handle *handle);
55 * Frees the handle and discards the underlying fd.
57 int fs_handle_close(struct fs_handle *handle);
59 ssize_t fs_handle_read(struct fs_handle *handle, void *buf, size_t count);
61 ssize_t fs_handle_write(struct fs_handle *handle, const void *buf, size_t count);
63 int fs_handle_truncate(struct fs_handle *handle, off_t offset);
65 off_t fs_handle_seek(struct fs_handle *handle, off_t offset, int whence);
67 #endif /* FS_HANDLE_H */