git/fsck-objects.c
Junio C Hamano 55dd55263b Protect commits recorded in reflog from pruning.
This teaches fsck-objects and prune to protect objects referred
to by reflog entries.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20 17:22:10 -08:00

632 lines
14 KiB
C

#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;
}
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++) {
const struct object_refs *refs;
struct object *obj = get_indexed_object(i);
if (!obj)
continue;
if (!obj->parsed) {
if (has_sha1_file(obj->sha1))
; /* it is in pack */
else
printf("missing %s %s\n",
typename(obj->type), sha1_to_hex(obj->sha1));
continue;
}
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));
}
}
if (show_unreachable && !(obj->flags & REACHABLE)) {
printf("unreachable %s %s\n",
typename(obj->type), sha1_to_hex(obj->sha1));
continue;
}
if (!obj->used) {
printf("dangling %s %s\n", typename(obj->type),
sha1_to_hex(obj->sha1));
}
}
}
/*
* 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 not found", 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, char *datail, 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-objects [--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;
}