static int do_one_ref(struct ref_entry *entry, void *cb_data)
{
struct ref_entry_cb *data = cb_data;
+ struct ref_entry *old_current_ref;
int retval;
+
if (prefixcmp(entry->name, data->base))
return 0;
!ref_resolves_to_object(entry))
return 0;
+ /* Store the old value, in case this is a recursive call: */
+ old_current_ref = current_ref;
current_ref = entry;
retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
entry->flag, data->cb_data);
- current_ref = NULL;
+ current_ref = old_current_ref;
return retval;
}
}
}
+/*
+ * Load all of the refs from the dir into our in-memory cache. The hard work
+ * of loading loose refs is done by get_ref_dir(), so we just need to recurse
+ * through all of the sub-directories. We do not even need to care about
+ * sorting, as traversal order does not matter to us.
+ */
+static void prime_ref_dir(struct ref_dir *dir)
+{
+ int i;
+ for (i = 0; i < dir->nr; i++) {
+ struct ref_entry *entry = dir->entries[i];
+ if (entry->flag & REF_DIR)
+ prime_ref_dir(get_ref_dir(entry));
+ }
+}
/*
* Return true iff refname1 and refname2 conflict with each other.
* Two reference names conflict if one of them exactly matches the
* when it is unlocked.
*/
struct lock_file *lock;
+
+ /* The metadata from when this packed-refs cache was read */
+ struct stat_validity validity;
};
/*
{
if (!--packed_refs->referrers) {
free_ref_entry(packed_refs->root);
+ stat_validity_clear(&packed_refs->validity);
free(packed_refs);
return 1;
} else {
*/
static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
{
+ const char *packed_refs_file;
+
+ if (*refs->name)
+ packed_refs_file = git_path_submodule(refs->name, "packed-refs");
+ else
+ packed_refs_file = git_path("packed-refs");
+
+ if (refs->packed &&
+ !stat_validity_check(&refs->packed->validity, packed_refs_file))
+ clear_packed_ref_cache(refs);
+
if (!refs->packed) {
- const char *packed_refs_file;
FILE *f;
refs->packed = xcalloc(1, sizeof(*refs->packed));
acquire_packed_ref_cache(refs->packed);
refs->packed->root = create_dir_entry(refs, "", 0, 0);
- if (*refs->name)
- packed_refs_file = git_path_submodule(refs->name, "packed-refs");
- else
- packed_refs_file = git_path("packed-refs");
f = fopen(packed_refs_file, "r");
if (f) {
+ stat_validity_update(&refs->packed->validity, fileno(f));
read_packed_refs(f, get_ref_dir(refs->packed->root));
fclose(f);
}
return find_ref(get_packed_refs(&ref_cache), refname);
}
+/*
+ * A loose ref file doesn't exist; check for a packed ref. The
+ * options are forwarded from resolve_safe_unsafe().
+ */
+static const char *handle_missing_loose_ref(const char *refname,
+ unsigned char *sha1,
+ int reading,
+ int *flag)
+{
+ struct ref_entry *entry;
+
+ /*
+ * The loose reference file does not exist; check for a packed
+ * reference.
+ */
+ entry = get_packed_ref(refname);
+ if (entry) {
+ hashcpy(sha1, entry->u.value.sha1);
+ if (flag)
+ *flag |= REF_ISPACKED;
+ return refname;
+ }
+ /* The reference is not a packed reference, either. */
+ if (reading) {
+ return NULL;
+ } else {
+ hashclr(sha1);
+ return refname;
+ }
+}
+
const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
{
int depth = MAXDEPTH;
git_snpath(path, sizeof(path), "%s", refname);
+ /*
+ * We might have to loop back here to avoid a race
+ * condition: first we lstat() the file, then we try
+ * to read it as a link or as a file. But if somebody
+ * changes the type of the file (file <-> directory
+ * <-> symlink) between the lstat() and reading, then
+ * we don't want to report that as an error but rather
+ * try again starting with the lstat().
+ */
+ stat_ref:
if (lstat(path, &st) < 0) {
- struct ref_entry *entry;
-
- if (errno != ENOENT)
- return NULL;
- /*
- * The loose reference file does not exist;
- * check for a packed reference.
- */
- entry = get_packed_ref(refname);
- if (entry) {
- hashcpy(sha1, entry->u.value.sha1);
- if (flag)
- *flag |= REF_ISPACKED;
- return refname;
- }
- /* The reference is not a packed reference, either. */
- if (reading) {
+ if (errno == ENOENT)
+ return handle_missing_loose_ref(refname, sha1,
+ reading, flag);
+ else
return NULL;
- } else {
- hashclr(sha1);
- return refname;
- }
}
/* Follow "normalized" - ie "refs/.." symlinks by hand */
if (S_ISLNK(st.st_mode)) {
len = readlink(path, buffer, sizeof(buffer)-1);
- if (len < 0)
- return NULL;
+ if (len < 0) {
+ if (errno == ENOENT || errno == EINVAL)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return NULL;
+ }
buffer[len] = 0;
if (!prefixcmp(buffer, "refs/") &&
!check_refname_format(buffer, 0)) {
* a ref
*/
fd = open(path, O_RDONLY);
- if (fd < 0)
- return NULL;
+ if (fd < 0) {
+ if (errno == ENOENT)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return NULL;
+ }
len = read_in_full(fd, buffer, sizeof(buffer)-1);
close(fd);
if (len < 0)
/*
* Is it a symbolic ref?
*/
- if (prefixcmp(buffer, "ref:"))
- break;
+ if (prefixcmp(buffer, "ref:")) {
+ /*
+ * Please note that FETCH_HEAD has a second
+ * line containing other data.
+ */
+ if (get_sha1_hex(buffer, sha1) ||
+ (buffer[40] != '\0' && !isspace(buffer[40]))) {
+ if (flag)
+ *flag |= REF_ISBROKEN;
+ return NULL;
+ }
+ return refname;
+ }
if (flag)
*flag |= REF_ISSYMREF;
buf = buffer + 4;
}
refname = strcpy(refname_buffer, buf);
}
- /* Please note that FETCH_HEAD has a second line containing other data. */
- if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
- if (flag)
- *flag |= REF_ISBROKEN;
- return NULL;
- }
- return refname;
}
char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
static int do_for_each_entry(struct ref_cache *refs, const char *base,
each_ref_entry_fn fn, void *cb_data)
{
- struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs);
- struct ref_dir *packed_dir = get_packed_ref_dir(packed_ref_cache);
- struct ref_dir *loose_dir = get_loose_refs(refs);
+ struct packed_ref_cache *packed_ref_cache;
+ struct ref_dir *loose_dir;
+ struct ref_dir *packed_dir;
int retval = 0;
+ /*
+ * We must make sure that all loose refs are read before accessing the
+ * packed-refs file; this avoids a race condition in which loose refs
+ * are migrated to the packed-refs file by a simultaneous process, but
+ * our in-memory view is from before the migration. get_packed_ref_cache()
+ * takes care of making sure our view is up to date with what is on
+ * disk.
+ */
+ loose_dir = get_loose_refs(refs);
+ if (base && *base) {
+ loose_dir = find_containing_dir(loose_dir, base, 0);
+ }
+ if (loose_dir)
+ prime_ref_dir(loose_dir);
+
+ packed_ref_cache = get_packed_ref_cache(refs);
acquire_packed_ref_cache(packed_ref_cache);
+ packed_dir = get_packed_ref_dir(packed_ref_cache);
if (base && *base) {
packed_dir = find_containing_dir(packed_dir, base, 0);
- loose_dir = find_containing_dir(loose_dir, base, 0);
}
if (packed_dir && loose_dir) {
static char *substitute_branch_name(const char **string, int *len)
{
struct strbuf buf = STRBUF_INIT;
- int ret = interpret_branch_name(*string, &buf);
+ int ret = interpret_branch_name(*string, *len, &buf);
if (ret == *len) {
size_t size;
}
struct ref_lock *lock_any_ref_for_update(const char *refname,
- const unsigned char *old_sha1, int flags)
+ const unsigned char *old_sha1,
+ int flags, int *type_p)
{
if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
return NULL;
- return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
+ return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
}
/*
{
struct packed_ref_cache *packed_ref_cache;
- /* Discard the old cache because it might be invalid: */
- clear_packed_ref_cache(&ref_cache);
if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
return -1;
- /* Read the current packed-refs while holding the lock: */
+ /*
+ * Get the current packed-refs while holding the lock. If the
+ * packed-refs file has been modified since we last read it,
+ * this will automatically invalidate the cache and re-read
+ * the packed-refs file.
+ */
packed_ref_cache = get_packed_ref_cache(&ref_cache);
packed_ref_cache->lock = &packlock;
/* Increment the reference count to prevent it from being freed: */
return 0;
}
-static int repack_without_ref(const char *refname)
+static int repack_without_refs(const char **refnames, int n)
{
struct ref_dir *packed;
struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
struct string_list_item *ref_to_delete;
+ int i, removed = 0;
- if (!get_packed_ref(refname))
- return 0; /* refname does not exist in packed refs */
+ /* Look for a packed ref */
+ for (i = 0; i < n; i++)
+ if (get_packed_ref(refnames[i]))
+ break;
+
+ /* Avoid locking if we have nothing to do */
+ if (i == n)
+ return 0; /* no refname exists in packed refs */
if (lock_packed_refs(0)) {
unable_to_lock_error(git_path("packed-refs"), errno);
- return error("cannot delete '%s' from packed refs", refname);
+ return error("cannot delete '%s' from packed refs", refnames[i]);
}
packed = get_packed_refs(&ref_cache);
- /* Remove refname from the cache: */
- if (remove_entry(packed, refname) == -1) {
+ /* Remove refnames from the cache */
+ for (i = 0; i < n; i++)
+ if (remove_entry(packed, refnames[i]) != -1)
+ removed = 1;
+ if (!removed) {
/*
- * The packed entry disappeared while we were
+ * All packed entries disappeared while we were
* acquiring the lock.
*/
rollback_packed_refs();
return 0;
}
- /* Remove any other accumulated cruft: */
+ /* Remove any other accumulated cruft */
do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
for_each_string_list_item(ref_to_delete, &refs_to_delete) {
if (remove_entry(packed, ref_to_delete->string) == -1)
die("internal error");
}
- /* Write what remains: */
+ /* Write what remains */
return commit_packed_refs();
}
-int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
+static int repack_without_ref(const char *refname)
{
- struct ref_lock *lock;
- int err, i = 0, ret = 0, flag = 0;
+ return repack_without_refs(&refname, 1);
+}
- lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
- if (!lock)
- return 1;
+static int delete_ref_loose(struct ref_lock *lock, int flag)
+{
if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
/* loose */
- i = strlen(lock->lk->filename) - 5; /* .lock */
+ int err, i = strlen(lock->lk->filename) - 5; /* .lock */
+
lock->lk->filename[i] = 0;
err = unlink_or_warn(lock->lk->filename);
- if (err && errno != ENOENT)
- ret = 1;
-
lock->lk->filename[i] = '.';
+ if (err && errno != ENOENT)
+ return 1;
}
+ return 0;
+}
+
+int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
+{
+ struct ref_lock *lock;
+ int ret = 0, flag = 0;
+
+ lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
+ if (!lock)
+ return 1;
+ ret |= delete_ref_loose(lock, flag);
+
/* removing the loose one could have resurrected an earlier
* packed one. Also, if it was not loose we need to repack
* without it.
return retval;
}
-int update_ref(const char *action, const char *refname,
- const unsigned char *sha1, const unsigned char *oldval,
- int flags, enum action_on_err onerr)
+static struct ref_lock *update_ref_lock(const char *refname,
+ const unsigned char *oldval,
+ int flags, int *type_p,
+ enum action_on_err onerr)
{
- static struct ref_lock *lock;
- lock = lock_any_ref_for_update(refname, oldval, flags);
+ struct ref_lock *lock;
+ lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
if (!lock) {
const char *str = "Cannot lock the ref '%s'.";
switch (onerr) {
case DIE_ON_ERR: die(str, refname); break;
case QUIET_ON_ERR: break;
}
- return 1;
}
+ return lock;
+}
+
+static int update_ref_write(const char *action, const char *refname,
+ const unsigned char *sha1, struct ref_lock *lock,
+ enum action_on_err onerr)
+{
if (write_ref_sha1(lock, sha1, action) < 0) {
const char *str = "Cannot update the ref '%s'.";
switch (onerr) {
return 0;
}
-struct ref *find_ref_by_name(const struct ref *list, const char *name)
+int update_ref(const char *action, const char *refname,
+ const unsigned char *sha1, const unsigned char *oldval,
+ int flags, enum action_on_err onerr)
{
- for ( ; list; list = list->next)
- if (!strcmp(list->name, name))
- return (struct ref *)list;
- return NULL;
+ struct ref_lock *lock;
+ lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
+ if (!lock)
+ return 1;
+ return update_ref_write(action, refname, sha1, lock, onerr);
+}
+
+static int ref_update_compare(const void *r1, const void *r2)
+{
+ const struct ref_update * const *u1 = r1;
+ const struct ref_update * const *u2 = r2;
+ return strcmp((*u1)->ref_name, (*u2)->ref_name);
+}
+
+static int ref_update_reject_duplicates(struct ref_update **updates, int n,
+ enum action_on_err onerr)
+{
+ int i;
+ for (i = 1; i < n; i++)
+ if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
+ const char *str =
+ "Multiple updates for ref '%s' not allowed.";
+ switch (onerr) {
+ case MSG_ON_ERR:
+ error(str, updates[i]->ref_name); break;
+ case DIE_ON_ERR:
+ die(str, updates[i]->ref_name); break;
+ case QUIET_ON_ERR:
+ break;
+ }
+ return 1;
+ }
+ return 0;
+}
+
+int update_refs(const char *action, const struct ref_update **updates_orig,
+ int n, enum action_on_err onerr)
+{
+ int ret = 0, delnum = 0, i;
+ struct ref_update **updates;
+ int *types;
+ struct ref_lock **locks;
+ const char **delnames;
+
+ if (!updates_orig || !n)
+ return 0;
+
+ /* Allocate work space */
+ updates = xmalloc(sizeof(*updates) * n);
+ types = xmalloc(sizeof(*types) * n);
+ locks = xcalloc(n, sizeof(*locks));
+ delnames = xmalloc(sizeof(*delnames) * n);
+
+ /* Copy, sort, and reject duplicate refs */
+ memcpy(updates, updates_orig, sizeof(*updates) * n);
+ qsort(updates, n, sizeof(*updates), ref_update_compare);
+ ret = ref_update_reject_duplicates(updates, n, onerr);
+ if (ret)
+ goto cleanup;
+
+ /* Acquire all locks while verifying old values */
+ for (i = 0; i < n; i++) {
+ locks[i] = update_ref_lock(updates[i]->ref_name,
+ (updates[i]->have_old ?
+ updates[i]->old_sha1 : NULL),
+ updates[i]->flags,
+ &types[i], onerr);
+ if (!locks[i]) {
+ ret = 1;
+ goto cleanup;
+ }
+ }
+
+ /* Perform updates first so live commits remain referenced */
+ for (i = 0; i < n; i++)
+ if (!is_null_sha1(updates[i]->new_sha1)) {
+ ret = update_ref_write(action,
+ updates[i]->ref_name,
+ updates[i]->new_sha1,
+ locks[i], onerr);
+ locks[i] = NULL; /* freed by update_ref_write */
+ if (ret)
+ goto cleanup;
+ }
+
+ /* Perform deletes now that updates are safely completed */
+ for (i = 0; i < n; i++)
+ if (locks[i]) {
+ delnames[delnum++] = locks[i]->ref_name;
+ ret |= delete_ref_loose(locks[i], types[i]);
+ }
+ ret |= repack_without_refs(delnames, delnum);
+ for (i = 0; i < delnum; i++)
+ unlink_or_warn(git_path("logs/%s", delnames[i]));
+ clear_loose_ref_cache(&ref_cache);
+
+cleanup:
+ for (i = 0; i < n; i++)
+ if (locks[i])
+ unlock_ref(locks[i]);
+ free(updates);
+ free(types);
+ free(locks);
+ free(delnames);
+ return ret;
}
/*