Commit | Line | Data |
---|---|---|
f5ea0241 | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
f5ea0241 | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
f5ea0241 | 5 | * |
f5ea0241 JG |
6 | */ |
7 | ||
8 | #ifndef FS_HANDLE_H | |
9 | #define FS_HANDLE_H | |
10 | ||
11 | #include <common/macros.h> | |
8bb66c3c | 12 | #include <stdio.h> |
f5ea0241 JG |
13 | |
14 | struct fs_handle; | |
15 | ||
16 | /* | |
17 | * Marks the handle as the most recently used and marks the 'fd' as | |
18 | * "in-use". This prevents the tracker from recycling the underlying | |
19 | * file descriptor while it is actively being used by a thread. | |
20 | * | |
21 | * Don't forget that the tracker may be initiating an fd 'suspension' | |
22 | * from another thread as the need to free an fd slot may arise from any | |
23 | * thread within the daemon. | |
24 | * | |
25 | * Note that a restorable fd should never be held for longer than | |
26 | * strictly necessary (e.g. the duration of a syscall()). | |
27 | * | |
28 | * Returns the fd on success, otherwise a negative value may be returned | |
29 | * if the restoration of the fd failed. | |
30 | */ | |
31 | LTTNG_HIDDEN | |
32 | int fs_handle_get_fd(struct fs_handle *handle); | |
33 | ||
34 | /* | |
35 | * Used by the caller to signal that it is no longer using the underlying fd and | |
36 | * that it may be safely suspended. | |
37 | */ | |
38 | LTTNG_HIDDEN | |
39 | void fs_handle_put_fd(struct fs_handle *handle); | |
40 | ||
41 | /* | |
42 | * Unlink the file associated to an fs_handle. Note that the unlink | |
43 | * operation will not be performed immediately. It will only be performed | |
44 | * once all references to the underlying file (through other fs_handle objects) | |
45 | * have been released. | |
46 | * | |
47 | * However, note that the file will be renamed so as to provide the observable | |
48 | * effect of an unlink(), that is removing a name from the filesystem. | |
49 | * | |
50 | * Returns 0 on success, otherwise a negative value will be returned | |
51 | * if the operation failed. | |
52 | */ | |
53 | LTTNG_HIDDEN | |
54 | int fs_handle_unlink(struct fs_handle *handle); | |
55 | ||
56 | /* | |
57 | * Frees the handle and discards the underlying fd. | |
58 | */ | |
59 | LTTNG_HIDDEN | |
60 | int fs_handle_close(struct fs_handle *handle); | |
61 | ||
8bb66c3c JG |
62 | LTTNG_HIDDEN |
63 | ssize_t fs_handle_read(struct fs_handle *handle, void *buf, size_t count); | |
64 | ||
65 | LTTNG_HIDDEN | |
66 | ssize_t fs_handle_write(struct fs_handle *handle, const void *buf, size_t count); | |
67 | ||
68 | LTTNG_HIDDEN | |
69 | int fs_handle_truncate(struct fs_handle *handle, off_t offset); | |
70 | ||
71 | LTTNG_HIDDEN | |
3e778ab0 | 72 | off_t fs_handle_seek(struct fs_handle *handle, off_t offset, int whence); |
8bb66c3c | 73 | |
f5ea0241 | 74 | #endif /* FS_HANDLE_H */ |