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-rw-r--r--fsck.c690
1 files changed, 690 insertions, 0 deletions
diff --git a/fsck.c b/fsck.c
new file mode 100644
index 0000000..558f0a6
--- /dev/null
+++ b/fsck.c
@@ -0,0 +1,690 @@
+#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"
+
+#define REACHABLE 0x0001
+#define SEEN 0x0002
+
+static int show_root;
+static int show_tags;
+static int show_unreachable;
+static int check_full;
+static int check_strict;
+static int keep_cache_objects;
+static unsigned char head_sha1[20];
+
+#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);
+ 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_file(obj->sha1))
+ return; /* it is in pack - forget about it */
+ printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
+ 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));
+ }
+ }
+}
+
+/*
+ * 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 unreacahble 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));
+ 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 (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();
+ 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_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;
+
+ desc.buf = item->buffer;
+ desc.size = 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;
+ has_zero_pad |= *(char *)desc.buf == '0';
+ update_tree_entry(&desc);
+
+ switch (mode) {
+ /*
+ * Standard modes..
+ */
+ case S_IFREG | 0755:
+ case S_IFREG | 0644:
+ case S_IFLNK:
+ case S_IFDIR:
+ 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_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 (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 (!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(unsigned char *sha1)
+{
+ struct object *obj = parse_object(sha1);
+ if (!obj)
+ 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;
+
+ 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 (!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_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+ struct object *obj;
+
+ obj = lookup_object(sha1);
+ if (!obj) {
+ if (has_sha1_file(sha1)) {
+ default_refs++;
+ return 0; /* it is in a pack */
+ }
+ error("%s: invalid sha1 pointer %s", refname, sha1_to_hex(sha1));
+ /* We'll continue with the rest despite the error.. */
+ return 0;
+ }
+ default_refs++;
+ obj->used = 1;
+ mark_reachable(obj, REACHABLE);
+
+ for_each_reflog_ent(refname, fsck_handle_reflog_ent, NULL);
+
+ return 0;
+}
+
+static void get_default_heads(void)
+{
+ for_each_ref(fsck_handle_ref, 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) {
+ error("No default references");
+ show_unreachable = 0;
+ }
+}
+
+static void fsck_object_dir(const char *path)
+{
+ int i;
+ 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;
+ const char *head_points_at = resolve_ref("HEAD", sha1, 1, &flag);
+
+ if (!head_points_at || !(flag & REF_ISSYMREF))
+ return error("HEAD is not a symbolic ref");
+ if (strncmp(head_points_at, "refs/heads/", 11))
+ return error("HEAD points to something strange (%s)",
+ head_points_at);
+ if (is_null_sha1(sha1))
+ return error("HEAD: not a valid git pointer");
+ return 0;
+}
+
+static int fsck_cache_tree(struct cache_tree *it)
+{
+ int i;
+ int err = 0;
+
+ 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;
+}
+
+int main(int argc, char **argv)
+{
+ int i, heads;
+
+ track_object_refs = 1;
+ setup_git_directory();
+
+ for (i = 1; i < argc; i++) {
+ const char *arg = argv[i];
+
+ if (!strcmp(arg, "--unreachable")) {
+ show_unreachable = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--tags")) {
+ show_tags = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--root")) {
+ show_root = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--cache")) {
+ keep_cache_objects = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--full")) {
+ check_full = 1;
+ continue;
+ }
+ if (!strcmp(arg, "--strict")) {
+ check_strict = 1;
+ continue;
+ }
+ if (*arg == '-')
+ usage("git-fsck [--tags] [--root] [[--unreachable] [--cache] [--full] [--strict] <head-sha1>*]");
+ }
+
+ 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) {
+ int num = num_packed_objects(p);
+ for (i = 0; i < num; i++) {
+ unsigned char sha1[20];
+ nth_packed_object_sha1(p, i, sha1);
+ fsck_sha1(sha1);
+ }
+ }
+ }
+
+ heads = 0;
+ for (i = 1; i < argc; i++) {
+ const char *arg = argv[i];
+
+ if (*arg == '-')
+ continue;
+
+ 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) {
+ int i;
+ read_cache();
+ for (i = 0; i < active_nr; i++) {
+ struct blob *blob = lookup_blob(active_cache[i]->sha1);
+ struct object *obj;
+ 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 0;
+}