builtin-fsck: move common object checking code to fsck.c
[git/git.git] / fsck.c
1 #include "cache.h"
2 #include "object.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "fsck.h"
9
10 static int fsck_walk_tree(struct tree *tree, fsck_walk_func walk, void *data)
11 {
12 struct tree_desc desc;
13 struct name_entry entry;
14 int res = 0;
15
16 if (parse_tree(tree))
17 return -1;
18
19 init_tree_desc(&desc, tree->buffer, tree->size);
20 while (tree_entry(&desc, &entry)) {
21 int result;
22
23 if (S_ISGITLINK(entry.mode))
24 continue;
25 if (S_ISDIR(entry.mode))
26 result = walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data);
27 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
28 result = walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data);
29 else {
30 result = error("in tree %s: entry %s has bad mode %.6o\n",
31 sha1_to_hex(tree->object.sha1), entry.path, entry.mode);
32 }
33 if (result < 0)
34 return result;
35 if (!res)
36 res = result;
37 }
38 return res;
39 }
40
41 static int fsck_walk_commit(struct commit *commit, fsck_walk_func walk, void *data)
42 {
43 struct commit_list *parents;
44 int res;
45 int result;
46
47 if (parse_commit(commit))
48 return -1;
49
50 result = walk((struct object *)commit->tree, OBJ_TREE, data);
51 if (result < 0)
52 return result;
53 res = result;
54
55 parents = commit->parents;
56 while (parents) {
57 result = walk((struct object *)parents->item, OBJ_COMMIT, data);
58 if (result < 0)
59 return result;
60 if (!res)
61 res = result;
62 parents = parents->next;
63 }
64 return res;
65 }
66
67 static int fsck_walk_tag(struct tag *tag, fsck_walk_func walk, void *data)
68 {
69 if (parse_tag(tag))
70 return -1;
71 return walk(tag->tagged, OBJ_ANY, data);
72 }
73
74 int fsck_walk(struct object *obj, fsck_walk_func walk, void *data)
75 {
76 if (!obj)
77 return -1;
78 switch (obj->type) {
79 case OBJ_BLOB:
80 return 0;
81 case OBJ_TREE:
82 return fsck_walk_tree((struct tree *)obj, walk, data);
83 case OBJ_COMMIT:
84 return fsck_walk_commit((struct commit *)obj, walk, data);
85 case OBJ_TAG:
86 return fsck_walk_tag((struct tag *)obj, walk, data);
87 default:
88 error("Unknown object type for %s", sha1_to_hex(obj->sha1));
89 return -1;
90 }
91 }
92
93 /*
94 * The entries in a tree are ordered in the _path_ order,
95 * which means that a directory entry is ordered by adding
96 * a slash to the end of it.
97 *
98 * So a directory called "a" is ordered _after_ a file
99 * called "a.c", because "a/" sorts after "a.c".
100 */
101 #define TREE_UNORDERED (-1)
102 #define TREE_HAS_DUPS (-2)
103
104 static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
105 {
106 int len1 = strlen(name1);
107 int len2 = strlen(name2);
108 int len = len1 < len2 ? len1 : len2;
109 unsigned char c1, c2;
110 int cmp;
111
112 cmp = memcmp(name1, name2, len);
113 if (cmp < 0)
114 return 0;
115 if (cmp > 0)
116 return TREE_UNORDERED;
117
118 /*
119 * Ok, the first <len> characters are the same.
120 * Now we need to order the next one, but turn
121 * a '\0' into a '/' for a directory entry.
122 */
123 c1 = name1[len];
124 c2 = name2[len];
125 if (!c1 && !c2)
126 /*
127 * git-write-tree used to write out a nonsense tree that has
128 * entries with the same name, one blob and one tree. Make
129 * sure we do not have duplicate entries.
130 */
131 return TREE_HAS_DUPS;
132 if (!c1 && S_ISDIR(mode1))
133 c1 = '/';
134 if (!c2 && S_ISDIR(mode2))
135 c2 = '/';
136 return c1 < c2 ? 0 : TREE_UNORDERED;
137 }
138
139 static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
140 {
141 int retval;
142 int has_full_path = 0;
143 int has_empty_name = 0;
144 int has_zero_pad = 0;
145 int has_bad_modes = 0;
146 int has_dup_entries = 0;
147 int not_properly_sorted = 0;
148 struct tree_desc desc;
149 unsigned o_mode;
150 const char *o_name;
151 const unsigned char *o_sha1;
152
153 init_tree_desc(&desc, item->buffer, item->size);
154
155 o_mode = 0;
156 o_name = NULL;
157 o_sha1 = NULL;
158 if (!desc.size)
159 return error_func(&item->object, FSCK_ERROR, "empty tree");
160
161 while (desc.size) {
162 unsigned mode;
163 const char *name;
164 const unsigned char *sha1;
165
166 sha1 = tree_entry_extract(&desc, &name, &mode);
167
168 if (strchr(name, '/'))
169 has_full_path = 1;
170 if (!*name)
171 has_empty_name = 1;
172 has_zero_pad |= *(char *)desc.buffer == '0';
173 update_tree_entry(&desc);
174
175 switch (mode) {
176 /*
177 * Standard modes..
178 */
179 case S_IFREG | 0755:
180 case S_IFREG | 0644:
181 case S_IFLNK:
182 case S_IFDIR:
183 case S_IFGITLINK:
184 break;
185 /*
186 * This is nonstandard, but we had a few of these
187 * early on when we honored the full set of mode
188 * bits..
189 */
190 case S_IFREG | 0664:
191 if (!strict)
192 break;
193 default:
194 has_bad_modes = 1;
195 }
196
197 if (o_name) {
198 switch (verify_ordered(o_mode, o_name, mode, name)) {
199 case TREE_UNORDERED:
200 not_properly_sorted = 1;
201 break;
202 case TREE_HAS_DUPS:
203 has_dup_entries = 1;
204 break;
205 default:
206 break;
207 }
208 }
209
210 o_mode = mode;
211 o_name = name;
212 o_sha1 = sha1;
213 }
214
215 retval = 0;
216 if (has_full_path)
217 retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
218 if (has_empty_name)
219 retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
220 if (has_zero_pad)
221 retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
222 if (has_bad_modes)
223 retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
224 if (has_dup_entries)
225 retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
226 if (not_properly_sorted)
227 retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
228 return retval;
229 }
230
231 static int fsck_commit(struct commit *commit, fsck_error error_func)
232 {
233 char *buffer = commit->buffer;
234 unsigned char tree_sha1[20], sha1[20];
235 struct commit_graft *graft;
236 int parents = 0;
237
238 if (!commit->date)
239 return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
240
241 if (memcmp(buffer, "tree ", 5))
242 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
243 if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
244 return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
245 buffer += 46;
246 while (!memcmp(buffer, "parent ", 7)) {
247 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
248 return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
249 buffer += 48;
250 parents++;
251 }
252 graft = lookup_commit_graft(commit->object.sha1);
253 if (graft) {
254 struct commit_list *p = commit->parents;
255 parents = 0;
256 while (p) {
257 p = p->next;
258 parents++;
259 }
260 if (graft->nr_parent == -1 && !parents)
261 ; /* shallow commit */
262 else if (graft->nr_parent != parents)
263 return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
264 } else {
265 struct commit_list *p = commit->parents;
266 while (p && parents) {
267 p = p->next;
268 parents--;
269 }
270 if (p || parents)
271 return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
272 }
273 if (memcmp(buffer, "author ", 7))
274 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
275 if (!commit->tree)
276 return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
277
278 return 0;
279 }
280
281 static int fsck_tag(struct tag *tag, fsck_error error_func)
282 {
283 struct object *tagged = tag->tagged;
284
285 if (!tagged)
286 return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
287 return 0;
288 }
289
290 int fsck_object(struct object *obj, int strict, fsck_error error_func)
291 {
292 if (!obj)
293 return error_func(obj, FSCK_ERROR, "no valid object to fsck");
294
295 if (obj->type == OBJ_BLOB)
296 return 0;
297 if (obj->type == OBJ_TREE)
298 return fsck_tree((struct tree *) obj, strict, error_func);
299 if (obj->type == OBJ_COMMIT)
300 return fsck_commit((struct commit *) obj, error_func);
301 if (obj->type == OBJ_TAG)
302 return fsck_tag((struct tag *) obj, error_func);
303
304 return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
305 obj->type);
306 }