diff options
Diffstat (limited to 'builtin-fsck.c')
| -rw-r--r-- | builtin-fsck.c | 784 |
1 files changed, 784 insertions, 0 deletions
diff --git a/builtin-fsck.c b/builtin-fsck.c new file mode 100644 index 0000000000..2a6e94deaf --- /dev/null +++ b/builtin-fsck.c @@ -0,0 +1,784 @@ +#include "builtin.h" +#include "cache.h" +#include "commit.h" +#include "tree.h" +#include "blob.h" +#include "tag.h" +#include "refs.h" +#include "pack.h" +#include "cache-tree.h" +#include "tree-walk.h" +#include "parse-options.h" + +#define REACHABLE 0x0001 +#define SEEN 0x0002 + +static int show_root; +static int show_tags; +static int show_unreachable; +static int include_reflogs = 1; +static int check_full; +static int check_strict; +static int keep_cache_objects; +static unsigned char head_sha1[20]; +static int errors_found; +static int write_lost_and_found; +static int verbose; +#define ERROR_OBJECT 01 +#define ERROR_REACHABLE 02 + +#ifdef NO_D_INO_IN_DIRENT +#define SORT_DIRENT 0 +#define DIRENT_SORT_HINT(de) 0 +#else +#define SORT_DIRENT 1 +#define DIRENT_SORT_HINT(de) ((de)->d_ino) +#endif + +static void objreport(struct object *obj, const char *severity, + const char *err, va_list params) +{ + fprintf(stderr, "%s in %s %s: ", + severity, typename(obj->type), sha1_to_hex(obj->sha1)); + vfprintf(stderr, err, params); + fputs("\n", stderr); +} + +static int objerror(struct object *obj, const char *err, ...) +{ + va_list params; + va_start(params, err); + errors_found |= ERROR_OBJECT; + objreport(obj, "error", err, params); + va_end(params); + return -1; +} + +static int objwarning(struct object *obj, const char *err, ...) +{ + va_list params; + va_start(params, err); + objreport(obj, "warning", err, params); + va_end(params); + return -1; +} + +/* + * Check a single reachable object + */ +static void check_reachable_object(struct object *obj) +{ + const struct object_refs *refs; + + /* + * We obviously want the object to be parsed, + * except if it was in a pack-file and we didn't + * do a full fsck + */ + if (!obj->parsed) { + if (has_sha1_pack(obj->sha1, NULL)) + return; /* it is in pack - forget about it */ + printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1)); + errors_found |= ERROR_REACHABLE; + return; + } + + /* + * Check that everything that we try to reference is also good. + */ + refs = lookup_object_refs(obj); + if (refs) { + unsigned j; + for (j = 0; j < refs->count; j++) { + struct object *ref = refs->ref[j]; + if (ref->parsed || + (has_sha1_file(ref->sha1))) + continue; + printf("broken link from %7s %s\n", + typename(obj->type), sha1_to_hex(obj->sha1)); + printf(" to %7s %s\n", + typename(ref->type), sha1_to_hex(ref->sha1)); + errors_found |= ERROR_REACHABLE; + } + } +} + +/* + * Check a single unreachable object + */ +static void check_unreachable_object(struct object *obj) +{ + /* + * Missing unreachable object? Ignore it. It's not like + * we miss it (since it can't be reached), nor do we want + * to complain about it being unreachable (since it does + * not exist). + */ + if (!obj->parsed) + return; + + /* + * Unreachable object that exists? Show it if asked to, + * since this is something that is prunable. + */ + if (show_unreachable) { + printf("unreachable %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1)); + return; + } + + /* + * "!used" means that nothing at all points to it, including + * other unreachable objects. In other words, it's the "tip" + * of some set of unreachable objects, usually a commit that + * got dropped. + * + * Such starting points are more interesting than some random + * set of unreachable objects, so we show them even if the user + * hasn't asked for _all_ unreachable objects. If you have + * deleted a branch by mistake, this is a prime candidate to + * start looking at, for example. + */ + if (!obj->used) { + printf("dangling %s %s\n", typename(obj->type), + sha1_to_hex(obj->sha1)); + if (write_lost_and_found) { + char *filename = git_path("lost-found/%s/%s", + obj->type == OBJ_COMMIT ? "commit" : "other", + sha1_to_hex(obj->sha1)); + FILE *f; + + if (safe_create_leading_directories(filename)) { + error("Could not create lost-found"); + return; + } + if (!(f = fopen(filename, "w"))) + die("Could not open %s", filename); + if (obj->type == OBJ_BLOB) { + enum object_type type; + unsigned long size; + char *buf = read_sha1_file(obj->sha1, + &type, &size); + if (buf) { + fwrite(buf, size, 1, f); + free(buf); + } + } else + fprintf(f, "%s\n", sha1_to_hex(obj->sha1)); + fclose(f); + } + return; + } + + /* + * Otherwise? It's there, it's unreachable, and some other unreachable + * object points to it. Ignore it - it's not interesting, and we showed + * all the interesting cases above. + */ +} + +static void check_object(struct object *obj) +{ + if (verbose) + fprintf(stderr, "Checking %s\n", sha1_to_hex(obj->sha1)); + + if (obj->flags & REACHABLE) + check_reachable_object(obj); + else + check_unreachable_object(obj); +} + +static void check_connectivity(void) +{ + int i, max; + + /* Look up all the requirements, warn about missing objects.. */ + max = get_max_object_index(); + if (verbose) + fprintf(stderr, "Checking connectivity (%d objects)\n", max); + + for (i = 0; i < max; i++) { + struct object *obj = get_indexed_object(i); + + if (obj) + check_object(obj); + } +} + +/* + * The entries in a tree are ordered in the _path_ order, + * which means that a directory entry is ordered by adding + * a slash to the end of it. + * + * So a directory called "a" is ordered _after_ a file + * called "a.c", because "a/" sorts after "a.c". + */ +#define TREE_UNORDERED (-1) +#define TREE_HAS_DUPS (-2) + +static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2) +{ + int len1 = strlen(name1); + int len2 = strlen(name2); + int len = len1 < len2 ? len1 : len2; + unsigned char c1, c2; + int cmp; + + cmp = memcmp(name1, name2, len); + if (cmp < 0) + return 0; + if (cmp > 0) + return TREE_UNORDERED; + + /* + * Ok, the first <len> characters are the same. + * Now we need to order the next one, but turn + * a '\0' into a '/' for a directory entry. + */ + c1 = name1[len]; + c2 = name2[len]; + if (!c1 && !c2) + /* + * git-write-tree used to write out a nonsense tree that has + * entries with the same name, one blob and one tree. Make + * sure we do not have duplicate entries. + */ + return TREE_HAS_DUPS; + if (!c1 && S_ISDIR(mode1)) + c1 = '/'; + if (!c2 && S_ISDIR(mode2)) + c2 = '/'; + return c1 < c2 ? 0 : TREE_UNORDERED; +} + +static int fsck_tree(struct tree *item) +{ + int retval; + int has_full_path = 0; + int has_empty_name = 0; + int has_zero_pad = 0; + int has_bad_modes = 0; + int has_dup_entries = 0; + int not_properly_sorted = 0; + struct tree_desc desc; + unsigned o_mode; + const char *o_name; + const unsigned char *o_sha1; + + if (verbose) + fprintf(stderr, "Checking tree %s\n", + sha1_to_hex(item->object.sha1)); + + init_tree_desc(&desc, item->buffer, item->size); + + o_mode = 0; + o_name = NULL; + o_sha1 = NULL; + while (desc.size) { + unsigned mode; + const char *name; + const unsigned char *sha1; + + sha1 = tree_entry_extract(&desc, &name, &mode); + + if (strchr(name, '/')) + has_full_path = 1; + if (!*name) + has_empty_name = 1; + has_zero_pad |= *(char *)desc.buffer == '0'; + update_tree_entry(&desc); + + switch (mode) { + /* + * Standard modes.. + */ + case S_IFREG | 0755: + case S_IFREG | 0644: + case S_IFLNK: + case S_IFDIR: + case S_IFGITLINK: + break; + /* + * This is nonstandard, but we had a few of these + * early on when we honored the full set of mode + * bits.. + */ + case S_IFREG | 0664: + if (!check_strict) + break; + default: + has_bad_modes = 1; + } + + if (o_name) { + switch (verify_ordered(o_mode, o_name, mode, name)) { + case TREE_UNORDERED: + not_properly_sorted = 1; + break; + case TREE_HAS_DUPS: + has_dup_entries = 1; + break; + default: + break; + } + } + + o_mode = mode; + o_name = name; + o_sha1 = sha1; + } + free(item->buffer); + item->buffer = NULL; + + retval = 0; + if (has_full_path) { + objwarning(&item->object, "contains full pathnames"); + } + if (has_empty_name) { + objwarning(&item->object, "contains empty pathname"); + } + if (has_zero_pad) { + objwarning(&item->object, "contains zero-padded file modes"); + } + if (has_bad_modes) { + objwarning(&item->object, "contains bad file modes"); + } + if (has_dup_entries) { + retval = objerror(&item->object, "contains duplicate file entries"); + } + if (not_properly_sorted) { + retval = objerror(&item->object, "not properly sorted"); + } + return retval; +} + +static int fsck_commit(struct commit *commit) +{ + char *buffer = commit->buffer; + unsigned char tree_sha1[20], sha1[20]; + + if (verbose) + fprintf(stderr, "Checking commit %s\n", + sha1_to_hex(commit->object.sha1)); + + if (memcmp(buffer, "tree ", 5)) + return objerror(&commit->object, "invalid format - expected 'tree' line"); + if (get_sha1_hex(buffer+5, tree_sha1) || buffer[45] != '\n') + return objerror(&commit->object, "invalid 'tree' line format - bad sha1"); + buffer += 46; + while (!memcmp(buffer, "parent ", 7)) { + if (get_sha1_hex(buffer+7, sha1) || buffer[47] != '\n') + return objerror(&commit->object, "invalid 'parent' line format - bad sha1"); + buffer += 48; + } + if (memcmp(buffer, "author ", 7)) + return objerror(&commit->object, "invalid format - expected 'author' line"); + free(commit->buffer); + commit->buffer = NULL; + if (!commit->tree) + return objerror(&commit->object, "could not load commit's tree %s", tree_sha1); + if (!commit->parents && show_root) + printf("root %s\n", sha1_to_hex(commit->object.sha1)); + if (!commit->date) + printf("bad commit date in %s\n", + sha1_to_hex(commit->object.sha1)); + return 0; +} + +static int fsck_tag(struct tag *tag) +{ + struct object *tagged = tag->tagged; + + if (verbose) + fprintf(stderr, "Checking tag %s\n", + sha1_to_hex(tag->object.sha1)); + + if (!tagged) { + return objerror(&tag->object, "could not load tagged object"); + } + if (!show_tags) + return 0; + + printf("tagged %s %s", typename(tagged->type), sha1_to_hex(tagged->sha1)); + printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1)); + return 0; +} + +static int fsck_sha1(const unsigned char *sha1) +{ + struct object *obj = parse_object(sha1); + if (!obj) { + errors_found |= ERROR_OBJECT; + return error("%s: object corrupt or missing", + sha1_to_hex(sha1)); + } + if (obj->flags & SEEN) + return 0; + obj->flags |= SEEN; + if (obj->type == OBJ_BLOB) + return 0; + if (obj->type == OBJ_TREE) + return fsck_tree((struct tree *) obj); + if (obj->type == OBJ_COMMIT) + return fsck_commit((struct commit *) obj); + if (obj->type == OBJ_TAG) + return fsck_tag((struct tag *) obj); + + /* By now, parse_object() would've returned NULL instead. */ + return objerror(obj, "unknown type '%d' (internal fsck error)", + obj->type); +} + +/* + * This is the sorting chunk size: make it reasonably + * big so that we can sort well.. + */ +#define MAX_SHA1_ENTRIES (1024) + +struct sha1_entry { + unsigned long ino; + unsigned char sha1[20]; +}; + +static struct { + unsigned long nr; + struct sha1_entry *entry[MAX_SHA1_ENTRIES]; +} sha1_list; + +static int ino_compare(const void *_a, const void *_b) +{ + const struct sha1_entry *a = _a, *b = _b; + unsigned long ino1 = a->ino, ino2 = b->ino; + return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0; +} + +static void fsck_sha1_list(void) +{ + int i, nr = sha1_list.nr; + + if (SORT_DIRENT) + qsort(sha1_list.entry, nr, + sizeof(struct sha1_entry *), ino_compare); + for (i = 0; i < nr; i++) { + struct sha1_entry *entry = sha1_list.entry[i]; + unsigned char *sha1 = entry->sha1; + + sha1_list.entry[i] = NULL; + fsck_sha1(sha1); + free(entry); + } + sha1_list.nr = 0; +} + +static void add_sha1_list(unsigned char *sha1, unsigned long ino) +{ + struct sha1_entry *entry = xmalloc(sizeof(*entry)); + int nr; + + entry->ino = ino; + hashcpy(entry->sha1, sha1); + nr = sha1_list.nr; + if (nr == MAX_SHA1_ENTRIES) { + fsck_sha1_list(); + nr = 0; + } + sha1_list.entry[nr] = entry; + sha1_list.nr = ++nr; +} + +static void fsck_dir(int i, char *path) +{ + DIR *dir = opendir(path); + struct dirent *de; + + if (!dir) + return; + + if (verbose) + fprintf(stderr, "Checking directory %s\n", path); + + while ((de = readdir(dir)) != NULL) { + char name[100]; + unsigned char sha1[20]; + int len = strlen(de->d_name); + + switch (len) { + case 2: + if (de->d_name[1] != '.') + break; + case 1: + if (de->d_name[0] != '.') + break; + continue; + case 38: + sprintf(name, "%02x", i); + memcpy(name+2, de->d_name, len+1); + if (get_sha1_hex(name, sha1) < 0) + break; + add_sha1_list(sha1, DIRENT_SORT_HINT(de)); + continue; + } + fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name); + } + closedir(dir); +} + +static int default_refs; + +static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1, + const char *email, unsigned long timestamp, int tz, + const char *message, void *cb_data) +{ + struct object *obj; + + if (verbose) + fprintf(stderr, "Checking reflog %s->%s\n", + sha1_to_hex(osha1), sha1_to_hex(nsha1)); + + if (!is_null_sha1(osha1)) { + obj = lookup_object(osha1); + if (obj) { + obj->used = 1; + mark_reachable(obj, REACHABLE); + } + } + obj = lookup_object(nsha1); + if (obj) { + obj->used = 1; + mark_reachable(obj, REACHABLE); + } + return 0; +} + +static int fsck_handle_reflog(const char *logname, const unsigned char *sha1, int flag, void *cb_data) +{ + for_each_reflog_ent(logname, fsck_handle_reflog_ent, NULL); + return 0; +} + +static int is_branch(const char *refname) +{ + return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/"); +} + +static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data) +{ + struct object *obj; + + obj = parse_object(sha1); + if (!obj) { + error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1)); + /* We'll continue with the rest despite the error.. */ + return 0; + } + if (obj->type != OBJ_COMMIT && is_branch(refname)) + error("%s: not a commit", refname); + default_refs++; + obj->used = 1; + mark_reachable(obj, REACHABLE); + + return 0; +} + +static void get_default_heads(void) +{ + for_each_ref(fsck_handle_ref, NULL); + if (include_reflogs) + for_each_reflog(fsck_handle_reflog, NULL); + + /* + * Not having any default heads isn't really fatal, but + * it does mean that "--unreachable" no longer makes any + * sense (since in this case everything will obviously + * be unreachable by definition. + * + * Showing dangling objects is valid, though (as those + * dangling objects are likely lost heads). + * + * So we just print a warning about it, and clear the + * "show_unreachable" flag. + */ + if (!default_refs) { + fprintf(stderr, "notice: No default references\n"); + show_unreachable = 0; + } +} + +static void fsck_object_dir(const char *path) +{ + int i; + + if (verbose) + fprintf(stderr, "Checking object directory\n"); + + for (i = 0; i < 256; i++) { + static char dir[4096]; + sprintf(dir, "%s/%02x", path, i); + fsck_dir(i, dir); + } + fsck_sha1_list(); +} + +static int fsck_head_link(void) +{ + unsigned char sha1[20]; + int flag; + int null_is_error = 0; + const char *head_points_at = resolve_ref("HEAD", sha1, 0, &flag); + + if (verbose) + fprintf(stderr, "Checking HEAD link\n"); + + if (!head_points_at) + return error("Invalid HEAD"); + if (!strcmp(head_points_at, "HEAD")) + /* detached HEAD */ + null_is_error = 1; + else if (prefixcmp(head_points_at, "refs/heads/")) + return error("HEAD points to something strange (%s)", + head_points_at); + if (is_null_sha1(sha1)) { + if (null_is_error) + return error("HEAD: detached HEAD points at nothing"); + fprintf(stderr, "notice: HEAD points to an unborn branch (%s)\n", + head_points_at + 11); + } + return 0; +} + +static int fsck_cache_tree(struct cache_tree *it) +{ + int i; + int err = 0; + + if (verbose) + fprintf(stderr, "Checking cache tree\n"); + + if (0 <= it->entry_count) { + struct object *obj = parse_object(it->sha1); + if (!obj) { + error("%s: invalid sha1 pointer in cache-tree", + sha1_to_hex(it->sha1)); + return 1; + } + mark_reachable(obj, REACHABLE); + obj->used = 1; + if (obj->type != OBJ_TREE) + err |= objerror(obj, "non-tree in cache-tree"); + } + for (i = 0; i < it->subtree_nr; i++) + err |= fsck_cache_tree(it->down[i]->cache_tree); + return err; +} + +static char const * const fsck_usage[] = { + "git-fsck [options] [<object>...]", + NULL +}; + +static struct option fsck_opts[] = { + OPT__VERBOSE(&verbose), + OPT_BOOLEAN(0, "unreachable", &show_unreachable, "show unreachable objects"), + OPT_BOOLEAN(0, "tags", &show_tags, "report tags"), + OPT_BOOLEAN(0, "root", &show_root, "report root nodes"), + OPT_BOOLEAN(0, "cache", &keep_cache_objects, "make index objects head nodes"), + OPT_BOOLEAN(0, "reflogs", &include_reflogs, "make reflogs head nodes (default)"), + OPT_BOOLEAN(0, "full", &check_full, "also consider alternate objects"), + OPT_BOOLEAN(0, "strict", &check_strict, "enable more strict checking"), + OPT_BOOLEAN(0, "lost-found", &write_lost_and_found, + "write dangling objects in .git/lost-found"), + OPT_END(), +}; + +int cmd_fsck(int argc, const char **argv, const char *prefix) +{ + int i, heads; + + track_object_refs = 1; + errors_found = 0; + + argc = parse_options(argc, argv, fsck_opts, fsck_usage, 0); + if (write_lost_and_found) { + check_full = 1; + include_reflogs = 0; + } + + fsck_head_link(); + fsck_object_dir(get_object_directory()); + if (check_full) { + struct alternate_object_database *alt; + struct packed_git *p; + prepare_alt_odb(); + for (alt = alt_odb_list; alt; alt = alt->next) { + char namebuf[PATH_MAX]; + int namelen = alt->name - alt->base; + memcpy(namebuf, alt->base, namelen); + namebuf[namelen - 1] = 0; + fsck_object_dir(namebuf); + } + prepare_packed_git(); + for (p = packed_git; p; p = p->next) + /* verify gives error messages itself */ + verify_pack(p, 0); + + for (p = packed_git; p; p = p->next) { + uint32_t j, num; + if (open_pack_index(p)) + continue; + num = p->num_objects; + for (j = 0; j < num; j++) + fsck_sha1(nth_packed_object_sha1(p, j)); + } + } + + heads = 0; + for (i = 1; i < argc; i++) { + const char *arg = argv[i]; + if (!get_sha1(arg, head_sha1)) { + struct object *obj = lookup_object(head_sha1); + + /* Error is printed by lookup_object(). */ + if (!obj) + continue; + + obj->used = 1; + mark_reachable(obj, REACHABLE); + heads++; + continue; + } + error("invalid parameter: expected sha1, got '%s'", arg); + } + + /* + * If we've not been given any explicit head information, do the + * default ones from .git/refs. We also consider the index file + * in this case (ie this implies --cache). + */ + if (!heads) { + get_default_heads(); + keep_cache_objects = 1; + } + + if (keep_cache_objects) { + read_cache(); + for (i = 0; i < active_nr; i++) { + unsigned int mode; + struct blob *blob; + struct object *obj; + + mode = ntohl(active_cache[i]->ce_mode); + if (S_ISGITLINK(mode)) + continue; + blob = lookup_blob(active_cache[i]->sha1); + if (!blob) + continue; + obj = &blob->object; + obj->used = 1; + mark_reachable(obj, REACHABLE); + } + if (active_cache_tree) + fsck_cache_tree(active_cache_tree); + } + + check_connectivity(); + return errors_found; +} |