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
 152         init_tree_desc(&desc, item->buffer, item->size);
 153
 154         o_mode = 0;
 155         o_name = NULL;
 156
 157         while (desc.size) {
 158                 unsigned mode;
 159                 const char *name;
 160
 161                 tree_entry_extract(&desc, &name, &mode);
 162
 163                 if (strchr(name, '/'))
 164                         has_full_path = 1;
 165                 if (!*name)
 166                         has_empty_name = 1;
 167                 has_zero_pad |= *(char *)desc.buffer == '0';
 168                 update_tree_entry(&desc);
 169
 170                 switch (mode) {
 171                 /*
 172                  * Standard modes..
 173                  */
 174                 case S_IFREG | 0755:
 175                 case S_IFREG | 0644:
 176                 case S_IFLNK:
 177                 case S_IFDIR:
 178                 case S_IFGITLINK:
 179                         break;
 180                 /*
 181                  * This is nonstandard, but we had a few of these
 182                  * early on when we honored the full set of mode
 183                  * bits..
 184                  */
 185                 case S_IFREG | 0664:
 186                         if (!strict)
 187                                 break;
 188                 default:
 189                         has_bad_modes = 1;
 190                 }
 191
 192                 if (o_name) {
 193                         switch (verify_ordered(o_mode, o_name, mode, name)) {
 194                         case TREE_UNORDERED:
 195                                 not_properly_sorted = 1;
 196                                 break;
 197                         case TREE_HAS_DUPS:
 198                                 has_dup_entries = 1;
 199                                 break;
 200                         default:
 201                                 break;
 202                         }
 203                 }
 204
 205                 o_mode = mode;
 206                 o_name = name;
 207         }
 208
 209         retval = 0;
 210         if (has_full_path)
 211                 retval += error_func(&item->object, FSCK_WARN, "contains full pathnames");
 212         if (has_empty_name)
 213                 retval += error_func(&item->object, FSCK_WARN, "contains empty pathname");
 214         if (has_zero_pad)
 215                 retval += error_func(&item->object, FSCK_WARN, "contains zero-padded file modes");
 216         if (has_bad_modes)
 217                 retval += error_func(&item->object, FSCK_WARN, "contains bad file modes");
 218         if (has_dup_entries)
 219                 retval += error_func(&item->object, FSCK_ERROR, "contains duplicate file entries");
 220         if (not_properly_sorted)
 221                 retval += error_func(&item->object, FSCK_ERROR, "not properly sorted");
 222         return retval;
 223 }
 224
 225 static int fsck_commit(struct commit *commit, fsck_error error_func)
 226 {
 227         char *buffer = commit->buffer;
 228         unsigned char tree_sha1[20], sha1[20];
 229         struct commit_graft *graft;
 230         int parents = 0;
 231
 232         if (commit->date == ULONG_MAX)
 233                 return error_func(&commit->object, FSCK_ERROR, "invalid author/committer line");
 234
 235         if (memcmp(buffer, "tree ", 5))
 236                 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'tree' line");
 237         if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n')
 238                 return error_func(&commit->object, FSCK_ERROR, "invalid 'tree' line format - bad sha1");
 239         buffer += 46;
 240         while (!memcmp(buffer, "parent ", 7)) {
 241                 if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n')
 242                         return error_func(&commit->object, FSCK_ERROR, "invalid 'parent' line format - bad sha1");
 243                 buffer += 48;
 244                 parents++;
 245         }
 246         graft = lookup_commit_graft(commit->object.sha1);
 247         if (graft) {
 248                 struct commit_list *p = commit->parents;
 249                 parents = 0;
 250                 while (p) {
 251                         p = p->next;
 252                         parents++;
 253                 }
 254                 if (graft->nr_parent == -1 && !parents)
 255                         ; /* shallow commit */
 256                 else if (graft->nr_parent != parents)
 257                         return error_func(&commit->object, FSCK_ERROR, "graft objects missing");
 258         } else {
 259                 struct commit_list *p = commit->parents;
 260                 while (p && parents) {
 261                         p = p->next;
 262                         parents--;
 263                 }
 264                 if (p || parents)
 265                         return error_func(&commit->object, FSCK_ERROR, "parent objects missing");
 266         }
 267         if (memcmp(buffer, "author ", 7))
 268                 return error_func(&commit->object, FSCK_ERROR, "invalid format - expected 'author' line");
 269         if (!commit->tree)
 270                 return error_func(&commit->object, FSCK_ERROR, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 271
 272         return 0;
 273 }
 274
 275 static int fsck_tag(struct tag *tag, fsck_error error_func)
 276 {
 277         struct object *tagged = tag->tagged;
 278
 279         if (!tagged)
 280                 return error_func(&tag->object, FSCK_ERROR, "could not load tagged object");
 281         return 0;
 282 }
 283
 284 int fsck_object(struct object *obj, int strict, fsck_error error_func)
 285 {
 286         if (!obj)
 287                 return error_func(obj, FSCK_ERROR, "no valid object to fsck");
 288
 289         if (obj->type == OBJ_BLOB)
 290                 return 0;
 291         if (obj->type == OBJ_TREE)
 292                 return fsck_tree((struct tree *) obj, strict, error_func);
 293         if (obj->type == OBJ_COMMIT)
 294                 return fsck_commit((struct commit *) obj, error_func);
 295         if (obj->type == OBJ_TAG)
 296                 return fsck_tag((struct tag *) obj, error_func);
 297
 298         return error_func(obj, FSCK_ERROR, "unknown type '%d' (internal fsck error)",
 299                           obj->type);
 300 }
 301
 302 int fsck_error_function(struct object *obj, int type, const char *fmt, ...)
 303 {
 304         va_list ap;
 305         int len;
 306         struct strbuf sb = STRBUF_INIT;
 307
 308         strbuf_addf(&sb, "object %s:", obj->sha1?sha1_to_hex(obj->sha1):"(null)");
 309
 310         va_start(ap, fmt);
 311         len = vsnprintf(sb.buf + sb.len, strbuf_avail(&sb), fmt, ap);
 312         va_end(ap);
 313
 314         if (len < 0)
 315                 len = 0;
 316         if (len >= strbuf_avail(&sb)) {
 317                 strbuf_grow(&sb, len + 2);
 318                 va_start(ap, fmt);
 319                 len = vsnprintf(sb.buf + sb.len, strbuf_avail(&sb), fmt, ap);
 320                 va_end(ap);
 321                 if (len >= strbuf_avail(&sb))
 322                         die("this should not happen, your snprintf is broken");
 323         }
 324
 325         error("%s", sb.buf);
 326         strbuf_release(&sb);
 327         return 1;
 328 }