1 | /* |
2 | * Copyright (c) 2015 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | // -- Document ID Tombstone Support -- |
30 | |
31 | #include <stdint.h> |
32 | #include <sys/resource.h> |
33 | #include <sys/signal.h> |
34 | #include <sys/vfs_context.h> |
35 | #include <sys/doc_tombstone.h> |
36 | #include <sys/vnode_internal.h> |
37 | #include <sys/fsevents.h> |
38 | #include <kern/thread.h> |
39 | #include <kern/kalloc.h> |
40 | #include <string.h> |
41 | |
42 | // |
43 | // This function gets the doc_tombstone structure for the |
44 | // current thread. If the thread doesn't have one, the |
45 | // structure is allocated. |
46 | // |
47 | struct doc_tombstone * |
48 | doc_tombstone_get(void) |
49 | { |
50 | struct uthread *ut; |
51 | ut = current_uthread(); |
52 | |
53 | if (ut->t_tombstone == NULL) { |
54 | ut->t_tombstone = kalloc_type(struct doc_tombstone, Z_WAITOK | Z_ZERO); |
55 | } |
56 | |
57 | return ut->t_tombstone; |
58 | } |
59 | |
60 | // |
61 | // This routine clears out the current tombstone for the |
62 | // current thread and if necessary passes the doc-id of |
63 | // the tombstone on to the dst_cnode. |
64 | // |
65 | // The caller is responsible for generating the appropriate |
66 | // fsevents. |
67 | // |
68 | void |
69 | doc_tombstone_clear(struct doc_tombstone *ut, vnode_t *old_vpp) |
70 | { |
71 | uint64_t old_id = ut->t_lastop_document_id; |
72 | |
73 | ut->t_lastop_document_id = 0; |
74 | ut->t_lastop_parent = NULL; |
75 | ut->t_lastop_parent_vid = 0; |
76 | ut->t_lastop_filename[0] = '\0'; |
77 | |
78 | // |
79 | // If the lastop item is still the same and needs to be cleared, |
80 | // clear it. The following isn't ideal because the vnode might |
81 | // have been recycled. |
82 | // |
83 | if (old_vpp) { |
84 | *old_vpp = NULL; |
85 | if (old_id && ut->t_lastop_item |
86 | && vnode_vid(vp: ut->t_lastop_item) == ut->t_lastop_item_vid) { |
87 | int res = vnode_get(ut->t_lastop_item); |
88 | if (!res) { |
89 | // Need to check vid again |
90 | if (vnode_vid(vp: ut->t_lastop_item) == ut->t_lastop_item_vid |
91 | && !ISSET(ut->t_lastop_item->v_lflag, VL_TERMINATE)) { |
92 | *old_vpp = ut->t_lastop_item; |
93 | } else { |
94 | vnode_put(vp: ut->t_lastop_item); |
95 | } |
96 | } |
97 | } |
98 | } |
99 | |
100 | // last, clear these now that we're all done |
101 | ut->t_lastop_item = NULL; |
102 | ut->t_lastop_fileid = 0; |
103 | ut->t_lastop_item_vid = 0; |
104 | } |
105 | |
106 | |
107 | // |
108 | // This function is used to filter out operations on temp |
109 | // filenames. We have to filter out operations on certain |
110 | // temp filenames to work-around questionable application |
111 | // behavior from apps like Autocad that perform unusual |
112 | // sequences of file system operations for a "safe save". |
113 | bool |
114 | doc_tombstone_should_ignore_name(const char *nameptr, int len) |
115 | { |
116 | size_t real_len; |
117 | if (len == 0) { |
118 | real_len = strlen(s: nameptr); |
119 | } else { |
120 | real_len = (size_t)len; |
121 | } |
122 | |
123 | if (strncmp(s1: nameptr, s2: "atmp" , n: 4) == 0 |
124 | || (real_len > 4 && strncmp(s1: nameptr + real_len - 4, s2: ".bak" , n: 4) == 0) |
125 | || (real_len > 4 && strncmp(s1: nameptr + real_len - 4, s2: ".tmp" , n: 4) == 0)) { |
126 | return true; |
127 | } |
128 | |
129 | return false; |
130 | } |
131 | |
132 | // |
133 | // Decide if we need to save a tombstone or not. Normally we always |
134 | // save a tombstone - but if there already is one and the name we're |
135 | // given is an ignorable name, then we will not save a tombstone. |
136 | // |
137 | bool |
138 | doc_tombstone_should_save(struct doc_tombstone *ut, struct vnode *vp, |
139 | struct componentname *cnp) |
140 | { |
141 | if (cnp->cn_nameptr == NULL) { |
142 | return false; |
143 | } |
144 | |
145 | if (ut->t_lastop_document_id && ut->t_lastop_item == vp |
146 | && doc_tombstone_should_ignore_name(nameptr: cnp->cn_nameptr, len: cnp->cn_namelen)) { |
147 | return false; |
148 | } |
149 | |
150 | return true; |
151 | } |
152 | |
153 | // |
154 | // This function saves a tombstone for the given vnode and name. The |
155 | // tombstone represents the parent directory and name where the document |
156 | // used to live and the document-id of that file. This info is recorded |
157 | // in the doc_tombstone structure hanging off the uthread (which assumes |
158 | // that all safe-save operations happen on the same thread). |
159 | // |
160 | // If later on the same parent/name combo comes back into existence then |
161 | // we'll preserve the doc-id from this vnode onto the new vnode. |
162 | // |
163 | // The caller is responsible for generating the appropriate |
164 | // fsevents. |
165 | // |
166 | void |
167 | doc_tombstone_save(struct vnode *dvp, struct vnode *vp, |
168 | struct componentname *cnp, uint64_t doc_id, |
169 | ino64_t file_id) |
170 | { |
171 | struct doc_tombstone *ut; |
172 | ut = doc_tombstone_get(); |
173 | |
174 | ut->t_lastop_parent = dvp; |
175 | ut->t_lastop_parent_vid = vnode_vid(vp: dvp); |
176 | ut->t_lastop_fileid = file_id; |
177 | ut->t_lastop_item = vp; |
178 | ut->t_lastop_item_vid = vp ? vnode_vid(vp) : 0; |
179 | ut->t_lastop_document_id = doc_id; |
180 | |
181 | strlcpy(dst: (char *)&ut->t_lastop_filename[0], src: cnp->cn_nameptr, n: sizeof(ut->t_lastop_filename)); |
182 | } |
183 | |