diff options
Diffstat (limited to 'refs/files-backend.c')
| -rw-r--r-- | refs/files-backend.c | 998 |
1 files changed, 333 insertions, 665 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c index f21a954ce7..dac33628b3 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -3,6 +3,7 @@ #include "../refs.h" #include "refs-internal.h" #include "ref-cache.h" +#include "packed-backend.h" #include "../iterator.h" #include "../dir-iterator.h" #include "../lockfile.h" @@ -11,44 +12,11 @@ struct ref_lock { char *ref_name; - struct lock_file *lk; + struct lock_file lk; struct object_id old_oid; }; /* - * Return true if refname, which has the specified oid and flags, can - * be resolved to an object in the database. If the referred-to object - * does not exist, emit a warning and return false. - */ -static int ref_resolves_to_object(const char *refname, - const struct object_id *oid, - unsigned int flags) -{ - if (flags & REF_ISBROKEN) - return 0; - if (!has_sha1_file(oid->hash)) { - error("%s does not point to a valid object!", refname); - return 0; - } - return 1; -} - -struct packed_ref_cache { - struct ref_cache *cache; - - /* - * Count of references to the data structure in this instance, - * including the pointer from files_ref_store::packed if any. - * The data will not be freed as long as the reference count - * is nonzero. - */ - unsigned int referrers; - - /* The metadata from when this packed-refs cache was read */ - struct stat_validity validity; -}; - -/* * Future: need to be in "struct repository" * when doing a full libification. */ @@ -58,54 +26,12 @@ struct files_ref_store { char *gitdir; char *gitcommondir; - char *packed_refs_path; struct ref_cache *loose; - struct packed_ref_cache *packed; - /* - * Lock used for the "packed-refs" file. Note that this (and - * thus the enclosing `files_ref_store`) must not be freed. - */ - struct lock_file packed_refs_lock; + struct ref_store *packed_ref_store; }; -/* - * Increment the reference count of *packed_refs. - */ -static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) -{ - packed_refs->referrers++; -} - -/* - * Decrease the reference count of *packed_refs. If it goes to zero, - * free *packed_refs and return true; otherwise return false. - */ -static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) -{ - if (!--packed_refs->referrers) { - free_ref_cache(packed_refs->cache); - stat_validity_clear(&packed_refs->validity); - free(packed_refs); - return 1; - } else { - return 0; - } -} - -static void clear_packed_ref_cache(struct files_ref_store *refs) -{ - if (refs->packed) { - struct packed_ref_cache *packed_refs = refs->packed; - - if (is_lock_file_locked(&refs->packed_refs_lock)) - die("BUG: packed-ref cache cleared while locked"); - refs->packed = NULL; - release_packed_ref_cache(packed_refs); - } -} - static void clear_loose_ref_cache(struct files_ref_store *refs) { if (refs->loose) { @@ -132,7 +58,8 @@ static struct ref_store *files_ref_store_create(const char *gitdir, get_common_dir_noenv(&sb, gitdir); refs->gitcommondir = strbuf_detach(&sb, NULL); strbuf_addf(&sb, "%s/packed-refs", refs->gitcommondir); - refs->packed_refs_path = strbuf_detach(&sb, NULL); + refs->packed_ref_store = packed_ref_store_create(sb.buf, flags); + strbuf_release(&sb); return ref_store; } @@ -175,169 +102,10 @@ static struct files_ref_store *files_downcast(struct ref_store *ref_store, return refs; } -/* The length of a peeled reference line in packed-refs, including EOL: */ -#define PEELED_LINE_LENGTH 42 - -/* - * The packed-refs header line that we write out. Perhaps other - * traits will be added later. The trailing space is required. - */ -static const char PACKED_REFS_HEADER[] = - "# pack-refs with: peeled fully-peeled \n"; - -/* - * Parse one line from a packed-refs file. Write the SHA1 to sha1. - * Return a pointer to the refname within the line (null-terminated), - * or NULL if there was a problem. - */ -static const char *parse_ref_line(struct strbuf *line, struct object_id *oid) -{ - const char *ref; - - if (parse_oid_hex(line->buf, oid, &ref) < 0) - return NULL; - if (!isspace(*ref++)) - return NULL; - - if (isspace(*ref)) - return NULL; - - if (line->buf[line->len - 1] != '\n') - return NULL; - line->buf[--line->len] = 0; - - return ref; -} - -/* - * Read from `packed_refs_file` into a newly-allocated - * `packed_ref_cache` and return it. The return value will already - * have its reference count incremented. - * - * A comment line of the form "# pack-refs with: " may contain zero or - * more traits. We interpret the traits as follows: - * - * No traits: - * - * Probably no references are peeled. But if the file contains a - * peeled value for a reference, we will use it. - * - * peeled: - * - * References under "refs/tags/", if they *can* be peeled, *are* - * peeled in this file. References outside of "refs/tags/" are - * probably not peeled even if they could have been, but if we find - * a peeled value for such a reference we will use it. - * - * fully-peeled: - * - * All references in the file that can be peeled are peeled. - * Inversely (and this is more important), any references in the - * file for which no peeled value is recorded is not peelable. This - * trait should typically be written alongside "peeled" for - * compatibility with older clients, but we do not require it - * (i.e., "peeled" is a no-op if "fully-peeled" is set). - */ -static struct packed_ref_cache *read_packed_refs(const char *packed_refs_file) -{ - FILE *f; - struct packed_ref_cache *packed_refs = xcalloc(1, sizeof(*packed_refs)); - struct ref_entry *last = NULL; - struct strbuf line = STRBUF_INIT; - enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; - struct ref_dir *dir; - - acquire_packed_ref_cache(packed_refs); - packed_refs->cache = create_ref_cache(NULL, NULL); - packed_refs->cache->root->flag &= ~REF_INCOMPLETE; - - f = fopen(packed_refs_file, "r"); - if (!f) { - if (errno == ENOENT) { - /* - * This is OK; it just means that no - * "packed-refs" file has been written yet, - * which is equivalent to it being empty. - */ - return packed_refs; - } else { - die_errno("couldn't read %s", packed_refs_file); - } - } - - stat_validity_update(&packed_refs->validity, fileno(f)); - - dir = get_ref_dir(packed_refs->cache->root); - while (strbuf_getwholeline(&line, f, '\n') != EOF) { - struct object_id oid; - const char *refname; - const char *traits; - - if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { - if (strstr(traits, " fully-peeled ")) - peeled = PEELED_FULLY; - else if (strstr(traits, " peeled ")) - peeled = PEELED_TAGS; - /* perhaps other traits later as well */ - continue; - } - - refname = parse_ref_line(&line, &oid); - if (refname) { - int flag = REF_ISPACKED; - - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - if (!refname_is_safe(refname)) - die("packed refname is dangerous: %s", refname); - oidclr(&oid); - flag |= REF_BAD_NAME | REF_ISBROKEN; - } - last = create_ref_entry(refname, &oid, flag); - if (peeled == PEELED_FULLY || - (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) - last->flag |= REF_KNOWS_PEELED; - add_ref_entry(dir, last); - continue; - } - if (last && - line.buf[0] == '^' && - line.len == PEELED_LINE_LENGTH && - line.buf[PEELED_LINE_LENGTH - 1] == '\n' && - !get_oid_hex(line.buf + 1, &oid)) { - oidcpy(&last->u.value.peeled, &oid); - /* - * Regardless of what the file header said, - * we definitely know the value of *this* - * reference: - */ - last->flag |= REF_KNOWS_PEELED; - } - } - - fclose(f); - strbuf_release(&line); - - return packed_refs; -} - -static const char *files_packed_refs_path(struct files_ref_store *refs) -{ - return refs->packed_refs_path; -} - static void files_reflog_path(struct files_ref_store *refs, struct strbuf *sb, const char *refname) { - if (!refname) { - /* - * FIXME: of course this is wrong in multi worktree - * setting. To be fixed real soon. - */ - strbuf_addf(sb, "%s/logs", refs->gitcommondir); - return; - } - switch (ref_type(refname)) { case REF_TYPE_PER_WORKTREE: case REF_TYPE_PSEUDOREF: @@ -371,70 +139,6 @@ static void files_ref_path(struct files_ref_store *refs, } /* - * Check that the packed refs cache (if any) still reflects the - * contents of the file. If not, clear the cache. - */ -static void validate_packed_ref_cache(struct files_ref_store *refs) -{ - if (refs->packed && - !stat_validity_check(&refs->packed->validity, - files_packed_refs_path(refs))) - clear_packed_ref_cache(refs); -} - -/* - * Get the packed_ref_cache for the specified files_ref_store, - * creating and populating it if it hasn't been read before or if the - * file has been changed (according to its `validity` field) since it - * was last read. On the other hand, if we hold the lock, then assume - * that the file hasn't been changed out from under us, so skip the - * extra `stat()` call in `stat_validity_check()`. - */ -static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs) -{ - const char *packed_refs_file = files_packed_refs_path(refs); - - if (!is_lock_file_locked(&refs->packed_refs_lock)) - validate_packed_ref_cache(refs); - - if (!refs->packed) - refs->packed = read_packed_refs(packed_refs_file); - - return refs->packed; -} - -static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) -{ - return get_ref_dir(packed_ref_cache->cache->root); -} - -static struct ref_dir *get_packed_refs(struct files_ref_store *refs) -{ - return get_packed_ref_dir(get_packed_ref_cache(refs)); -} - -/* - * Add a reference to the in-memory packed reference cache. This may - * only be called while the packed-refs file is locked (see - * lock_packed_refs()). To actually write the packed-refs file, call - * commit_packed_refs(). - */ -static void add_packed_ref(struct files_ref_store *refs, - const char *refname, const struct object_id *oid) -{ - struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(refs); - - if (!is_lock_file_locked(&refs->packed_refs_lock)) - die("BUG: packed refs not locked"); - - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) - die("Reference has invalid format: '%s'", refname); - - add_ref_entry(get_packed_ref_dir(packed_ref_cache), - create_ref_entry(refname, oid, REF_ISPACKED)); -} - -/* * Read the loose references from the namespace dirname into dir * (without recursing). dirname must end with '/'. dir must be the * directory entry corresponding to dirname. @@ -556,39 +260,6 @@ static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs) return refs->loose; } -/* - * Return the ref_entry for the given refname from the packed - * references. If it does not exist, return NULL. - */ -static struct ref_entry *get_packed_ref(struct files_ref_store *refs, - const char *refname) -{ - return find_ref_entry(get_packed_refs(refs), refname); -} - -/* - * A loose ref file doesn't exist; check for a packed ref. - */ -static int resolve_packed_ref(struct files_ref_store *refs, - const char *refname, - unsigned char *sha1, unsigned int *flags) -{ - struct ref_entry *entry; - - /* - * The loose reference file does not exist; check for a packed - * reference. - */ - entry = get_packed_ref(refs, refname); - if (entry) { - hashcpy(sha1, entry->u.value.oid.hash); - *flags |= REF_ISPACKED; - return 0; - } - /* refname is not a packed reference. */ - return -1; -} - static int files_read_raw_ref(struct ref_store *ref_store, const char *refname, unsigned char *sha1, struct strbuf *referent, unsigned int *type) @@ -632,7 +303,8 @@ stat_ref: if (lstat(path, &st) < 0) { if (errno != ENOENT) goto out; - if (resolve_packed_ref(refs, refname, sha1, type)) { + if (refs_read_raw_ref(refs->packed_ref_store, refname, + sha1, referent, type)) { errno = ENOENT; goto out; } @@ -671,7 +343,8 @@ stat_ref: * ref is supposed to be, there could still be a * packed ref: */ - if (resolve_packed_ref(refs, refname, sha1, type)) { + if (refs_read_raw_ref(refs->packed_ref_store, refname, + sha1, referent, type)) { errno = EISDIR; goto out; } @@ -736,9 +409,7 @@ out: static void unlock_ref(struct ref_lock *lock) { - /* Do not free lock->lk -- atexit() still looks at them */ - if (lock->lk) - rollback_lock_file(lock->lk); + rollback_lock_file(&lock->lk); free(lock->ref_name); free(lock); } @@ -852,10 +523,9 @@ retry: goto error_return; } - if (!lock->lk) - lock->lk = xcalloc(1, sizeof(struct lock_file)); - - if (hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) < 0) { + if (hold_lock_file_for_update_timeout( + &lock->lk, ref_file.buf, LOCK_NO_DEREF, + get_files_ref_lock_timeout_ms()) < 0) { if (errno == ENOENT && --attempts_remaining > 0) { /* * Maybe somebody just deleted one of the @@ -950,11 +620,11 @@ retry: /* * If the ref did not exist and we are creating it, - * make sure there is no existing ref that conflicts - * with refname: + * make sure there is no existing packed ref that + * conflicts with refname: */ if (refs_verify_refname_available( - &refs->base, refname, + refs->packed_ref_store, refname, extras, skip, err)) goto error_return; } @@ -1001,15 +671,9 @@ static int files_peel_ref(struct ref_store *ref_store, * be expensive and (b) loose references anyway usually do not * have REF_KNOWS_PEELED. */ - if (flag & REF_ISPACKED) { - struct ref_entry *r = get_packed_ref(refs, refname); - if (r) { - if (peel_entry(r, 0)) - return -1; - hashcpy(sha1, r->u.value.peeled.hash); - return 0; - } - } + if (flag & REF_ISPACKED && + !refs_peel_ref(refs->packed_ref_store, refname, sha1)) + return 0; return peel_object(base, sha1); } @@ -1017,7 +681,6 @@ static int files_peel_ref(struct ref_store *ref_store, struct files_ref_iterator { struct ref_iterator base; - struct packed_ref_cache *packed_ref_cache; struct ref_iterator *iter0; unsigned int flags; }; @@ -1070,7 +733,6 @@ static int files_ref_iterator_abort(struct ref_iterator *ref_iterator) if (iter->iter0) ok = ref_iterator_abort(iter->iter0); - release_packed_ref_cache(iter->packed_ref_cache); base_ref_iterator_free(ref_iterator); return ok; } @@ -1112,18 +774,28 @@ static struct ref_iterator *files_ref_iterator_begin( * (If they've already been read, that's OK; we only need to * guarantee that they're read before the packed refs, not * *how much* before.) After that, we call - * get_packed_ref_cache(), which internally checks whether the - * packed-ref cache is up to date with what is on disk, and - * re-reads it if not. + * packed_ref_iterator_begin(), which internally checks + * whether the packed-ref cache is up to date with what is on + * disk, and re-reads it if not. */ loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), prefix, 1); - iter->packed_ref_cache = get_packed_ref_cache(refs); - acquire_packed_ref_cache(iter->packed_ref_cache); - packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache, - prefix, 0); + /* + * The packed-refs file might contain broken references, for + * example an old version of a reference that points at an + * object that has since been garbage-collected. This is OK as + * long as there is a corresponding loose reference that + * overrides it, and we don't want to emit an error message in + * this case. So ask the packed_ref_store for all of its + * references, and (if needed) do our own check for broken + * ones in files_ref_iterator_advance(), after we have merged + * the packed and loose references. + */ + packed_iter = refs_ref_iterator_begin( + refs->packed_ref_store, prefix, 0, + DO_FOR_EACH_INCLUDE_BROKEN); iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter); iter->flags = flags; @@ -1181,7 +853,9 @@ static int create_reflock(const char *path, void *cb) { struct lock_file *lk = cb; - return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0; + return hold_lock_file_for_update_timeout( + lk, path, LOCK_NO_DEREF, + get_files_ref_lock_timeout_ms()) < 0 ? -1 : 0; } /* @@ -1255,17 +929,15 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, * our refname. */ if (is_null_oid(&lock->old_oid) && - refs_verify_refname_available(&refs->base, refname, + refs_verify_refname_available(refs->packed_ref_store, refname, extras, skip, err)) { last_errno = ENOTDIR; goto error_return; } - lock->lk = xcalloc(1, sizeof(struct lock_file)); - lock->ref_name = xstrdup(refname); - if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) { + if (raceproof_create_file(ref_file.buf, create_reflock, &lock->lk)) { last_errno = errno; unable_to_lock_message(ref_file.buf, errno, err); goto error_return; @@ -1287,124 +959,6 @@ static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs, return lock; } -/* - * Write an entry to the packed-refs file for the specified refname. - * If peeled is non-NULL, write it as the entry's peeled value. - */ -static void write_packed_entry(FILE *fh, const char *refname, - const unsigned char *sha1, - const unsigned char *peeled) -{ - fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); - if (peeled) - fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); -} - -/* - * Lock the packed-refs file for writing. Flags is passed to - * hold_lock_file_for_update(). Return 0 on success. On errors, set - * errno appropriately and return a nonzero value. - */ -static int lock_packed_refs(struct files_ref_store *refs, int flags) -{ - static int timeout_configured = 0; - static int timeout_value = 1000; - struct packed_ref_cache *packed_ref_cache; - - files_assert_main_repository(refs, "lock_packed_refs"); - - if (!timeout_configured) { - git_config_get_int("core.packedrefstimeout", &timeout_value); - timeout_configured = 1; - } - - if (hold_lock_file_for_update_timeout( - &refs->packed_refs_lock, files_packed_refs_path(refs), - flags, timeout_value) < 0) - return -1; - - /* - * Now that we hold the `packed-refs` lock, make sure that our - * cache matches the current version of the file. Normally - * `get_packed_ref_cache()` does that for us, but that - * function assumes that when the file is locked, any existing - * cache is still valid. We've just locked the file, but it - * might have changed the moment *before* we locked it. - */ - validate_packed_ref_cache(refs); - - packed_ref_cache = get_packed_ref_cache(refs); - /* Increment the reference count to prevent it from being freed: */ - acquire_packed_ref_cache(packed_ref_cache); - return 0; -} - -/* - * Write the current version of the packed refs cache from memory to - * disk. The packed-refs file must already be locked for writing (see - * lock_packed_refs()). Return zero on success. On errors, set errno - * and return a nonzero value - */ -static int commit_packed_refs(struct files_ref_store *refs) -{ - struct packed_ref_cache *packed_ref_cache = - get_packed_ref_cache(refs); - int ok, error = 0; - int save_errno = 0; - FILE *out; - struct ref_iterator *iter; - - files_assert_main_repository(refs, "commit_packed_refs"); - - if (!is_lock_file_locked(&refs->packed_refs_lock)) - die("BUG: packed-refs not locked"); - - out = fdopen_lock_file(&refs->packed_refs_lock, "w"); - if (!out) - die_errno("unable to fdopen packed-refs descriptor"); - - fprintf_or_die(out, "%s", PACKED_REFS_HEADER); - - iter = cache_ref_iterator_begin(packed_ref_cache->cache, NULL, 0); - while ((ok = ref_iterator_advance(iter)) == ITER_OK) { - struct object_id peeled; - int peel_error = ref_iterator_peel(iter, &peeled); - - write_packed_entry(out, iter->refname, iter->oid->hash, - peel_error ? NULL : peeled.hash); - } - - if (ok != ITER_DONE) - die("error while iterating over references"); - - if (commit_lock_file(&refs->packed_refs_lock)) { - save_errno = errno; - error = -1; - } - release_packed_ref_cache(packed_ref_cache); - errno = save_errno; - return error; -} - -/* - * Rollback the lockfile for the packed-refs file, and discard the - * in-memory packed reference cache. (The packed-refs file will be - * read anew if it is needed again after this function is called.) - */ -static void rollback_packed_refs(struct files_ref_store *refs) -{ - struct packed_ref_cache *packed_ref_cache = - get_packed_ref_cache(refs); - - files_assert_main_repository(refs, "rollback_packed_refs"); - - if (!is_lock_file_locked(&refs->packed_refs_lock)) - die("BUG: packed-refs not locked"); - rollback_lock_file(&refs->packed_refs_lock); - release_packed_ref_cache(packed_ref_cache); - clear_packed_ref_cache(refs); -} - struct ref_to_prune { struct ref_to_prune *next; unsigned char sha1[20]; @@ -1487,11 +1041,17 @@ static void prune_ref(struct files_ref_store *refs, struct ref_to_prune *r) strbuf_release(&err); } -static void prune_refs(struct files_ref_store *refs, struct ref_to_prune *r) +/* + * Prune the loose versions of the references in the linked list + * `*refs_to_prune`, freeing the entries in the list as we go. + */ +static void prune_refs(struct files_ref_store *refs, struct ref_to_prune **refs_to_prune) { - while (r) { + while (*refs_to_prune) { + struct ref_to_prune *r = *refs_to_prune; + *refs_to_prune = r->next; prune_ref(refs, r); - r = r->next; + free(r); } } @@ -1527,12 +1087,16 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags) files_downcast(ref_store, REF_STORE_WRITE | REF_STORE_ODB, "pack_refs"); struct ref_iterator *iter; - struct ref_dir *packed_refs; int ok; struct ref_to_prune *refs_to_prune = NULL; + struct strbuf err = STRBUF_INIT; + struct ref_transaction *transaction; + + transaction = ref_store_transaction_begin(refs->packed_ref_store, &err); + if (!transaction) + return -1; - lock_packed_refs(refs, LOCK_DIE_ON_ERROR); - packed_refs = get_packed_refs(refs); + packed_refs_lock(refs->packed_ref_store, LOCK_DIE_ON_ERROR, &err); iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), NULL, 0); while ((ok = ref_iterator_advance(iter)) == ITER_OK) { @@ -1541,29 +1105,19 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags) * in the packed ref cache. If the reference should be * pruned, also add it to refs_to_prune. */ - struct ref_entry *packed_entry; - if (!should_pack_ref(iter->refname, iter->oid, iter->flags, flags)) continue; /* - * Create an entry in the packed-refs cache equivalent - * to the one from the loose ref cache, except that - * we don't copy the peeled status, because we want it - * to be re-peeled. + * Add a reference creation for this reference to the + * packed-refs transaction: */ - packed_entry = find_ref_entry(packed_refs, iter->refname); - if (packed_entry) { - /* Overwrite existing packed entry with info from loose entry */ - packed_entry->flag = REF_ISPACKED; - oidcpy(&packed_entry->u.value.oid, iter->oid); - } else { - packed_entry = create_ref_entry(iter->refname, iter->oid, - REF_ISPACKED); - add_ref_entry(packed_refs, packed_entry); - } - oidclr(&packed_entry->u.value.peeled); + if (ref_transaction_update(transaction, iter->refname, + iter->oid->hash, NULL, + REF_NODEREF, NULL, &err)) + die("failure preparing to create packed reference %s: %s", + iter->refname, err.buf); /* Schedule the loose reference for pruning if requested. */ if ((flags & PACK_REFS_PRUNE)) { @@ -1577,67 +1131,16 @@ static int files_pack_refs(struct ref_store *ref_store, unsigned int flags) if (ok != ITER_DONE) die("error while iterating over references"); - if (commit_packed_refs(refs)) - die_errno("unable to overwrite old ref-pack file"); - - prune_refs(refs, refs_to_prune); - return 0; -} - -/* - * Rewrite the packed-refs file, omitting any refs listed in - * 'refnames'. On error, leave packed-refs unchanged, write an error - * message to 'err', and return a nonzero value. - * - * The refs in 'refnames' needn't be sorted. `err` must not be NULL. - */ -static int repack_without_refs(struct files_ref_store *refs, - struct string_list *refnames, struct strbuf *err) -{ - struct ref_dir *packed; - struct string_list_item *refname; - int ret, needs_repacking = 0, removed = 0; - - files_assert_main_repository(refs, "repack_without_refs"); - assert(err); - - /* Look for a packed ref */ - for_each_string_list_item(refname, refnames) { - if (get_packed_ref(refs, refname->string)) { - needs_repacking = 1; - break; - } - } + if (ref_transaction_commit(transaction, &err)) + die("unable to write new packed-refs: %s", err.buf); - /* Avoid locking if we have nothing to do */ - if (!needs_repacking) - return 0; /* no refname exists in packed refs */ + ref_transaction_free(transaction); - if (lock_packed_refs(refs, 0)) { - unable_to_lock_message(files_packed_refs_path(refs), errno, err); - return -1; - } - packed = get_packed_refs(refs); + packed_refs_unlock(refs->packed_ref_store); - /* Remove refnames from the cache */ - for_each_string_list_item(refname, refnames) - if (remove_entry_from_dir(packed, refname->string) != -1) - removed = 1; - if (!removed) { - /* - * All packed entries disappeared while we were - * acquiring the lock. - */ - rollback_packed_refs(refs); - return 0; - } - - /* Write what remains */ - ret = commit_packed_refs(refs); - if (ret) - strbuf_addf(err, "unable to overwrite old ref-pack file: %s", - strerror(errno)); - return ret; + prune_refs(refs, &refs_to_prune); + strbuf_release(&err); + return 0; } static int files_delete_refs(struct ref_store *ref_store, const char *msg, @@ -1651,24 +1154,16 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg, if (!refnames->nr) return 0; - result = repack_without_refs(refs, refnames, &err); - if (result) { - /* - * If we failed to rewrite the packed-refs file, then - * it is unsafe to try to remove loose refs, because - * doing so might expose an obsolete packed value for - * a reference that might even point at an object that - * has been garbage collected. - */ - if (refnames->nr == 1) - error(_("could not delete reference %s: %s"), - refnames->items[0].string, err.buf); - else - error(_("could not delete references: %s"), err.buf); + if (packed_refs_lock(refs->packed_ref_store, 0, &err)) + goto error; - goto out; + if (refs_delete_refs(refs->packed_ref_store, msg, refnames, flags)) { + packed_refs_unlock(refs->packed_ref_store); + goto error; } + packed_refs_unlock(refs->packed_ref_store); + for (i = 0; i < refnames->nr; i++) { const char *refname = refnames->items[i].string; @@ -1676,9 +1171,24 @@ static int files_delete_refs(struct ref_store *ref_store, const char *msg, result |= error(_("could not remove reference %s"), refname); } -out: strbuf_release(&err); return result; + +error: + /* + * If we failed to rewrite the packed-refs file, then it is + * unsafe to try to remove loose refs, because doing so might + * expose an obsolete packed value for a reference that might + * even point at an object that has been garbage collected. + */ + if (refnames->nr == 1) + error(_("could not delete reference %s: %s"), + refnames->items[0].string, err.buf); + else + error(_("could not delete references: %s"), err.buf); + + strbuf_release(&err); + return -1; } /* @@ -1892,16 +1402,16 @@ static int files_rename_ref(struct ref_store *ref_store, return ret; } -static int close_ref(struct ref_lock *lock) +static int close_ref_gently(struct ref_lock *lock) { - if (close_lock_file(lock->lk)) + if (close_lock_file_gently(&lock->lk)) return -1; return 0; } static int commit_ref(struct ref_lock *lock) { - char *path = get_locked_file_path(lock->lk); + char *path = get_locked_file_path(&lock->lk); struct stat st; if (!lstat(path, &st) && S_ISDIR(st.st_mode)) { @@ -1925,7 +1435,7 @@ static int commit_ref(struct ref_lock *lock) free(path); } - if (commit_lock_file(lock->lk)) + if (commit_lock_file(&lock->lk)) return -1; return 0; } @@ -2117,12 +1627,12 @@ static int write_ref_to_lockfile(struct ref_lock *lock, unlock_ref(lock); return -1; } - fd = get_lock_file_fd(lock->lk); + fd = get_lock_file_fd(&lock->lk); if (write_in_full(fd, oid_to_hex(oid), GIT_SHA1_HEXSZ) < 0 || write_in_full(fd, &term, 1) < 0 || - close_ref(lock) < 0) { + close_ref_gently(lock) < 0) { strbuf_addf(err, - "couldn't write '%s'", get_lock_file_path(lock->lk)); + "couldn't write '%s'", get_lock_file_path(&lock->lk)); unlock_ref(lock); return -1; } @@ -2199,7 +1709,7 @@ static int create_ref_symlink(struct ref_lock *lock, const char *target) { int ret = -1; #ifndef NO_SYMLINK_HEAD - char *ref_path = get_locked_file_path(lock->lk); + char *ref_path = get_locked_file_path(&lock->lk); unlink(ref_path); ret = symlink(target, ref_path); free(ref_path); @@ -2235,14 +1745,14 @@ static int create_symref_locked(struct files_ref_store *refs, return 0; } - if (!fdopen_lock_file(lock->lk, "w")) + if (!fdopen_lock_file(&lock->lk, "w")) return error("unable to fdopen %s: %s", - lock->lk->tempfile.filename.buf, strerror(errno)); + lock->lk.tempfile->filename.buf, strerror(errno)); update_symref_reflog(refs, lock, refname, target, logmsg); /* no error check; commit_ref will check ferror */ - fprintf(lock->lk->tempfile.fp, "ref: %s\n", target); + fprintf(lock->lk.tempfile->fp, "ref: %s\n", target); if (commit_ref(lock) < 0) return error("unable to write symref for %s: %s", refname, strerror(errno)); @@ -2549,23 +2059,63 @@ static struct ref_iterator_vtable files_reflog_iterator_vtable = { files_reflog_iterator_abort }; -static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store) +static struct ref_iterator *reflog_iterator_begin(struct ref_store *ref_store, + const char *gitdir) { - struct files_ref_store *refs = - files_downcast(ref_store, REF_STORE_READ, - "reflog_iterator_begin"); struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter)); struct ref_iterator *ref_iterator = &iter->base; struct strbuf sb = STRBUF_INIT; base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable); - files_reflog_path(refs, &sb, NULL); + strbuf_addf(&sb, "%s/logs", gitdir); iter->dir_iterator = dir_iterator_begin(sb.buf); iter->ref_store = ref_store; strbuf_release(&sb); + return ref_iterator; } +static enum iterator_selection reflog_iterator_select( + struct ref_iterator *iter_worktree, + struct ref_iterator *iter_common, + void *cb_data) +{ + if (iter_worktree) { + /* + * We're a bit loose here. We probably should ignore + * common refs if they are accidentally added as + * per-worktree refs. + */ + return ITER_SELECT_0; + } else if (iter_common) { + if (ref_type(iter_common->refname) == REF_TYPE_NORMAL) + return ITER_SELECT_1; + + /* + * The main ref store may contain main worktree's + * per-worktree refs, which should be ignored + */ + return ITER_SKIP_1; + } else + return ITER_DONE; +} + +static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store) +{ + struct files_ref_store *refs = + files_downcast(ref_store, REF_STORE_READ, + "reflog_iterator_begin"); + + if (!strcmp(refs->gitdir, refs->gitcommondir)) { + return reflog_iterator_begin(ref_store, refs->gitcommondir); + } else { + return merge_ref_iterator_begin( + reflog_iterator_begin(ref_store, refs->gitdir), + reflog_iterator_begin(ref_store, refs->gitcommondir), + reflog_iterator_select, refs); + } +} + /* * If update is a direct update of head_ref (the reference pointed to * by HEAD), then add an extra REF_LOG_ONLY update for HEAD. @@ -2589,11 +2139,10 @@ static int split_head_update(struct ref_update *update, /* * First make sure that HEAD is not already in the - * transaction. This insertion is O(N) in the transaction + * transaction. This check is O(lg N) in the transaction * size, but it happens at most once per transaction. */ - item = string_list_insert(affected_refnames, "HEAD"); - if (item->util) { + if (string_list_has_string(affected_refnames, "HEAD")) { /* An entry already existed */ strbuf_addf(err, "multiple updates for 'HEAD' (including one " @@ -2608,6 +2157,14 @@ static int split_head_update(struct ref_update *update, update->new_oid.hash, update->old_oid.hash, update->msg); + /* + * Add "HEAD". This insertion is O(N) in the transaction + * size, but it happens at most once per transaction. + * Add new_update->refname instead of a literal "HEAD". + */ + if (strcmp(new_update->refname, "HEAD")) + BUG("%s unexpectedly not 'HEAD'", new_update->refname); + item = string_list_insert(affected_refnames, new_update->refname); item->util = new_update; return 0; @@ -2634,13 +2191,12 @@ static int split_symref_update(struct files_ref_store *refs, /* * First make sure that referent is not already in the - * transaction. This insertion is O(N) in the transaction + * transaction. This check is O(lg N) in the transaction * size, but it happens at most once per symref in a * transaction. */ - item = string_list_insert(affected_refnames, referent); - if (item->util) { - /* An entry already existed */ + if (string_list_has_string(affected_refnames, referent)) { + /* An entry already exists */ strbuf_addf(err, "multiple updates for '%s' (including one " "via symref '%s') are not allowed", @@ -2675,6 +2231,17 @@ static int split_symref_update(struct files_ref_store *refs, update->flags |= REF_LOG_ONLY | REF_NODEREF; update->flags &= ~REF_HAVE_OLD; + /* + * Add the referent. This insertion is O(N) in the transaction + * size, but it happens at most once per symref in a + * transaction. Make sure to add new_update->refname, which will + * be valid as long as affected_refnames is in use, and NOT + * referent, which might soon be freed by our caller. + */ + item = string_list_insert(affected_refnames, new_update->refname); + if (item->util) + BUG("%s unexpectedly found in affected_refnames", + new_update->refname); item->util = new_update; return 0; @@ -2746,7 +2313,7 @@ static int lock_ref_for_update(struct files_ref_store *refs, struct strbuf referent = STRBUF_INIT; int mustexist = (update->flags & REF_HAVE_OLD) && !is_null_oid(&update->old_oid); - int ret; + int ret = 0; struct ref_lock *lock; files_assert_main_repository(refs, "lock_ref_for_update"); @@ -2758,7 +2325,7 @@ static int lock_ref_for_update(struct files_ref_store *refs, ret = split_head_update(update, transaction, head_ref, affected_refnames, err); if (ret) - return ret; + goto out; } ret = lock_raw_ref(refs, update->refname, mustexist, @@ -2772,7 +2339,7 @@ static int lock_ref_for_update(struct files_ref_store *refs, strbuf_addf(err, "cannot lock ref '%s': %s", original_update_refname(update), reason); free(reason); - return ret; + goto out; } update->backend_data = lock; @@ -2791,10 +2358,12 @@ static int lock_ref_for_update(struct files_ref_store *refs, strbuf_addf(err, "cannot lock ref '%s': " "error reading reference", original_update_refname(update)); - return -1; + ret = TRANSACTION_GENERIC_ERROR; + goto out; } } else if (check_old_oid(update, &lock->old_oid, err)) { - return TRANSACTION_GENERIC_ERROR; + ret = TRANSACTION_GENERIC_ERROR; + goto out; } } else { /* @@ -2808,13 +2377,15 @@ static int lock_ref_for_update(struct files_ref_store *refs, referent.buf, transaction, affected_refnames, err); if (ret) - return ret; + goto out; } } else { struct ref_update *parent_update; - if (check_old_oid(update, &lock->old_oid, err)) - return TRANSACTION_GENERIC_ERROR; + if (check_old_oid(update, &lock->old_oid, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto out; + } /* * If this update is happening indirectly because of a @@ -2851,7 +2422,8 @@ static int lock_ref_for_update(struct files_ref_store *refs, "cannot update ref '%s': %s", update->refname, write_err); free(write_err); - return TRANSACTION_GENERIC_ERROR; + ret = TRANSACTION_GENERIC_ERROR; + goto out; } else { update->flags |= REF_NEEDS_COMMIT; } @@ -2862,22 +2434,35 @@ static int lock_ref_for_update(struct files_ref_store *refs, * the lockfile is still open. Close it to * free up the file descriptor: */ - if (close_ref(lock)) { + if (close_ref_gently(lock)) { strbuf_addf(err, "couldn't close '%s.lock'", update->refname); - return TRANSACTION_GENERIC_ERROR; + ret = TRANSACTION_GENERIC_ERROR; + goto out; } } - return 0; + +out: + strbuf_release(&referent); + return ret; } +struct files_transaction_backend_data { + struct ref_transaction *packed_transaction; + int packed_refs_locked; +}; + /* * Unlock any references in `transaction` that are still locked, and * mark the transaction closed. */ -static void files_transaction_cleanup(struct ref_transaction *transaction) +static void files_transaction_cleanup(struct files_ref_store *refs, + struct ref_transaction *transaction) { size_t i; + struct files_transaction_backend_data *backend_data = + transaction->backend_data; + struct strbuf err = STRBUF_INIT; for (i = 0; i < transaction->nr; i++) { struct ref_update *update = transaction->updates[i]; @@ -2889,6 +2474,17 @@ static void files_transaction_cleanup(struct ref_transaction *transaction) } } + if (backend_data->packed_transaction && + ref_transaction_abort(backend_data->packed_transaction, &err)) { + error("error aborting transaction: %s", err.buf); + strbuf_release(&err); + } + + if (backend_data->packed_refs_locked) + packed_refs_unlock(refs->packed_ref_store); + + free(backend_data); + transaction->state = REF_TRANSACTION_CLOSED; } @@ -2905,12 +2501,17 @@ static int files_transaction_prepare(struct ref_store *ref_store, char *head_ref = NULL; int head_type; struct object_id head_oid; + struct files_transaction_backend_data *backend_data; + struct ref_transaction *packed_transaction = NULL; assert(err); if (!transaction->nr) goto cleanup; + backend_data = xcalloc(1, sizeof(*backend_data)); + transaction->backend_data = backend_data; + /* * Fail if a refname appears more than once in the * transaction. (If we end up splitting up any updates using @@ -2977,6 +2578,41 @@ static int files_transaction_prepare(struct ref_store *ref_store, head_ref, &affected_refnames, err); if (ret) break; + + if (update->flags & REF_DELETING && + !(update->flags & REF_LOG_ONLY) && + !(update->flags & REF_ISPRUNING)) { + /* + * This reference has to be deleted from + * packed-refs if it exists there. + */ + if (!packed_transaction) { + packed_transaction = ref_store_transaction_begin( + refs->packed_ref_store, err); + if (!packed_transaction) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + + backend_data->packed_transaction = + packed_transaction; + } + + ref_transaction_add_update( + packed_transaction, update->refname, + update->flags & ~REF_HAVE_OLD, + update->new_oid.hash, update->old_oid.hash, + NULL); + } + } + + if (packed_transaction) { + if (packed_refs_lock(refs->packed_ref_store, 0, err)) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + backend_data->packed_refs_locked = 1; + ret = ref_transaction_prepare(packed_transaction, err); } cleanup: @@ -2984,7 +2620,7 @@ cleanup: string_list_clear(&affected_refnames, 0); if (ret) - files_transaction_cleanup(transaction); + files_transaction_cleanup(refs, transaction); else transaction->state = REF_TRANSACTION_PREPARED; @@ -2999,9 +2635,10 @@ static int files_transaction_finish(struct ref_store *ref_store, files_downcast(ref_store, 0, "ref_transaction_finish"); size_t i; int ret = 0; - struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; - struct string_list_item *ref_to_delete; struct strbuf sb = STRBUF_INIT; + struct files_transaction_backend_data *backend_data; + struct ref_transaction *packed_transaction; + assert(err); @@ -3010,6 +2647,9 @@ static int files_transaction_finish(struct ref_store *ref_store, return 0; } + backend_data = transaction->backend_data; + packed_transaction = backend_data->packed_transaction; + /* Perform updates first so live commits remain referenced */ for (i = 0; i < transaction->nr; i++) { struct ref_update *update = transaction->updates[i]; @@ -3045,7 +2685,44 @@ static int files_transaction_finish(struct ref_store *ref_store, } } } - /* Perform deletes now that updates are safely completed */ + + /* + * Now that updates are safely completed, we can perform + * deletes. First delete the reflogs of any references that + * will be deleted, since (in the unexpected event of an + * error) leaving a reference without a reflog is less bad + * than leaving a reflog without a reference (the latter is a + * mildly invalid repository state): + */ + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + if (update->flags & REF_DELETING && + !(update->flags & REF_LOG_ONLY) && + !(update->flags & REF_ISPRUNING)) { + strbuf_reset(&sb); + files_reflog_path(refs, &sb, update->refname); + if (!unlink_or_warn(sb.buf)) + try_remove_empty_parents(refs, update->refname, + REMOVE_EMPTY_PARENTS_REFLOG); + } + } + + /* + * Perform deletes now that updates are safely completed. + * + * First delete any packed versions of the references, while + * retaining the packed-refs lock: + */ + if (packed_transaction) { + ret = ref_transaction_commit(packed_transaction, err); + ref_transaction_free(packed_transaction); + packed_transaction = NULL; + backend_data->packed_transaction = NULL; + if (ret) + goto cleanup; + } + + /* Now delete the loose versions of the references: */ for (i = 0; i < transaction->nr; i++) { struct ref_update *update = transaction->updates[i]; struct ref_lock *lock = update->backend_data; @@ -3063,31 +2740,13 @@ static int files_transaction_finish(struct ref_store *ref_store, } update->flags |= REF_DELETED_LOOSE; } - - if (!(update->flags & REF_ISPRUNING)) - string_list_append(&refs_to_delete, - lock->ref_name); } } - if (repack_without_refs(refs, &refs_to_delete, err)) { - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - - /* Delete the reflogs of any references that were deleted: */ - for_each_string_list_item(ref_to_delete, &refs_to_delete) { - strbuf_reset(&sb); - files_reflog_path(refs, &sb, ref_to_delete->string); - if (!unlink_or_warn(sb.buf)) - try_remove_empty_parents(refs, ref_to_delete->string, - REMOVE_EMPTY_PARENTS_REFLOG); - } - clear_loose_ref_cache(refs); cleanup: - files_transaction_cleanup(transaction); + files_transaction_cleanup(refs, transaction); for (i = 0; i < transaction->nr; i++) { struct ref_update *update = transaction->updates[i]; @@ -3105,7 +2764,6 @@ cleanup: } strbuf_release(&sb); - string_list_clear(&refs_to_delete, 0); return ret; } @@ -3113,7 +2771,10 @@ static int files_transaction_abort(struct ref_store *ref_store, struct ref_transaction *transaction, struct strbuf *err) { - files_transaction_cleanup(transaction); + struct files_ref_store *refs = + files_downcast(ref_store, 0, "ref_transaction_abort"); + + files_transaction_cleanup(refs, transaction); return 0; } @@ -3135,6 +2796,7 @@ static int files_initial_transaction_commit(struct ref_store *ref_store, size_t i; int ret = 0; struct string_list affected_refnames = STRING_LIST_INIT_NODUP; + struct ref_transaction *packed_transaction = NULL; assert(err); @@ -3167,6 +2829,12 @@ static int files_initial_transaction_commit(struct ref_store *ref_store, &affected_refnames)) die("BUG: initial ref transaction called with existing refs"); + packed_transaction = ref_store_transaction_begin(refs->packed_ref_store, err); + if (!packed_transaction) { + ret = TRANSACTION_GENERIC_ERROR; + goto cleanup; + } + for (i = 0; i < transaction->nr; i++) { struct ref_update *update = transaction->updates[i]; @@ -3179,32 +2847,31 @@ static int files_initial_transaction_commit(struct ref_store *ref_store, ret = TRANSACTION_NAME_CONFLICT; goto cleanup; } + + /* + * Add a reference creation for this reference to the + * packed-refs transaction: + */ + ref_transaction_add_update(packed_transaction, update->refname, + update->flags & ~REF_HAVE_OLD, + update->new_oid.hash, update->old_oid.hash, + NULL); } - if (lock_packed_refs(refs, 0)) { - strbuf_addf(err, "unable to lock packed-refs file: %s", - strerror(errno)); + if (packed_refs_lock(refs->packed_ref_store, 0, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } - for (i = 0; i < transaction->nr; i++) { - struct ref_update *update = transaction->updates[i]; - - if ((update->flags & REF_HAVE_NEW) && - !is_null_oid(&update->new_oid)) - add_packed_ref(refs, update->refname, - &update->new_oid); - } - - if (commit_packed_refs(refs)) { - strbuf_addf(err, "unable to commit packed-refs file: %s", - strerror(errno)); + if (initial_ref_transaction_commit(packed_transaction, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } cleanup: + if (packed_transaction) + ref_transaction_free(packed_transaction); + packed_refs_unlock(refs->packed_ref_store); transaction->state = REF_TRANSACTION_CLOSED; string_list_clear(&affected_refnames, 0); return ret; @@ -3333,16 +3000,17 @@ static int files_reflog_expire(struct ref_store *ref_store, !(type & REF_ISSYMREF) && !is_null_oid(&cb.last_kept_oid); - if (close_lock_file(&reflog_lock)) { + if (close_lock_file_gently(&reflog_lock)) { status |= error("couldn't write %s: %s", log_file, strerror(errno)); + rollback_lock_file(&reflog_lock); } else if (update && - (write_in_full(get_lock_file_fd(lock->lk), + (write_in_full(get_lock_file_fd(&lock->lk), oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) < 0 || - write_str_in_full(get_lock_file_fd(lock->lk), "\n") < 0 || - close_ref(lock) < 0)) { + write_str_in_full(get_lock_file_fd(&lock->lk), "\n") < 1 || + close_ref_gently(lock) < 0)) { status |= error("couldn't write %s", - get_lock_file_path(lock->lk)); + get_lock_file_path(&lock->lk)); rollback_lock_file(&reflog_lock); } else if (commit_lock_file(&reflog_lock)) { status |= error("unable to write reflog '%s' (%s)", |