From: Junio C Hamano Date: Sun, 27 Aug 2017 05:55:09 +0000 (-0700) Subject: Merge branch 'mh/ref-lock-entry' X-Git-Tag: v2.15.0-rc0~116 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/f2dd90fc1c38ce1d1ebf626e39ddafad130875ae?ds=inline;hp=-c Merge branch 'mh/ref-lock-entry' The code to acquire a lock on a reference (e.g. while accepting a push from a client) used to immediately fail when the reference is already locked---now it waits for a very short while and retries, which can make it succeed if the lock holder was holding it during a read-only operation. * mh/ref-lock-entry: refs: retry acquiring reference locks for 100ms --- f2dd90fc1c38ce1d1ebf626e39ddafad130875ae diff --combined Documentation/config.txt index 9b42e0ca73,2c04b9dfb4..dc4e3f58a2 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@@ -216,15 -216,15 +216,15 @@@ boolean: synonyms are accepted for 'true' and 'false'; these are all case-insensitive. - true;; Boolean true can be spelled as `yes`, `on`, `true`, - or `1`. Also, a variable defined without `= ` + true;; Boolean true literals are `yes`, `on`, `true`, + and `1`. Also, a variable defined without `= ` is taken as true. - false;; Boolean false can be spelled as `no`, `off`, - `false`, or `0`. + false;; Boolean false literals are `no`, `off`, `false`, + `0` and the empty string. + When converting value to the canonical form using `--bool` type -specifier; 'git config' will ensure that the output is "true" or +specifier, 'git config' will ensure that the output is "true" or "false" (spelled in lowercase). integer:: @@@ -776,6 -776,12 +776,12 @@@ core.commentChar: If set to "auto", `git-commit` would select a character that is not the beginning character of any line in existing commit messages. + core.filesRefLockTimeout:: + The length of time, in milliseconds, to retry when trying to + lock an individual reference. Value 0 means not to retry at + all; -1 means to try indefinitely. Default is 100 (i.e., + retry for 100ms). + core.packedRefsTimeout:: The length of time, in milliseconds, to retry when trying to lock the `packed-refs` file. Value 0 means not to retry at @@@ -1077,25 -1083,14 +1083,25 @@@ This does not affect linkgit:git-format 'git-diff-{asterisk}' plumbing commands. Can be overridden on the command line with the `--color[=]` option. +diff.colorMoved:: + If set to either a valid `` or a true value, moved lines + in a diff are colored differently, for details of valid modes + see '--color-moved' in linkgit:git-diff[1]. If simply set to + true the default color mode will be used. When set to false, + moved lines are not colored. + color.diff.:: Use customized color for diff colorization. `` specifies which part of the patch to use the specified color, and is one of `context` (context text - `plain` is a historical synonym), `meta` (metainformation), `frag` (hunk header), 'func' (function in hunk header), `old` (removed lines), - `new` (added lines), `commit` (commit headers), or `whitespace` - (highlighting whitespace errors). + `new` (added lines), `commit` (commit headers), `whitespace` + (highlighting whitespace errors), `oldMoved` (deleted lines), + `newMoved` (added lines), `oldMovedDimmed`, `oldMovedAlternative`, + `oldMovedAlternativeDimmed`, `newMovedDimmed`, `newMovedAlternative` + and `newMovedAlternativeDimmed` (See the '' + setting of '--color-moved' in linkgit:git-diff[1] for details). color.decorate.:: Use customized color for 'git log --decorate' output. `` is one @@@ -1564,13 -1559,11 +1570,13 @@@ gc..reflogExpireUnreachable: gc.rerereResolved:: Records of conflicted merge you resolved earlier are kept for this many days when 'git rerere gc' is run. + You can also use more human-readable "1.month.ago", etc. The default is 60 days. See linkgit:git-rerere[1]. gc.rerereUnresolved:: Records of conflicted merge you have not resolved are kept for this many days when 'git rerere gc' is run. + You can also use more human-readable "1.month.ago", etc. The default is 15 days. See linkgit:git-rerere[1]. gitcvs.commitMsgAnnotation:: @@@ -2925,8 -2918,8 +2931,8 @@@ sendemail.smtpsslcertpath: sendemail..*:: Identity-specific versions of the 'sendemail.*' parameters - found below, taking precedence over those when the this - identity is selected, through command-line or + found below, taking precedence over those when this + identity is selected, through either the command-line or `sendemail.identity`. sendemail.aliasesFile:: diff --combined refs.c index 3d549a8970,748e34d7c2..b0106b8162 --- a/refs.c +++ b/refs.c @@@ -174,24 -174,6 +174,24 @@@ int refname_is_safe(const char *refname return 1; } +/* + * 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. + */ +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; +} + char *refs_resolve_refdup(struct ref_store *refs, const char *refname, int resolve_flags, unsigned char *sha1, int *flags) @@@ -579,6 -561,21 +579,21 @@@ enum ref_type ref_type(const char *refn return REF_TYPE_NORMAL; } + long get_files_ref_lock_timeout_ms(void) + { + static int configured = 0; + + /* The default timeout is 100 ms: */ + static int timeout_ms = 100; + + if (!configured) { + git_config_get_int("core.filesreflocktimeout", &timeout_ms); + configured = 1; + } + + return timeout_ms; + } + static int write_pseudoref(const char *pseudoref, const unsigned char *sha1, const unsigned char *old_sha1, struct strbuf *err) { @@@ -591,7 -588,9 +606,9 @@@ strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1)); filename = git_path("%s", pseudoref); - fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR); + fd = hold_lock_file_for_update_timeout(&lock, filename, + LOCK_DIE_ON_ERROR, + get_files_ref_lock_timeout_ms()); if (fd < 0) { strbuf_addf(err, "could not open '%s' for writing: %s", filename, strerror(errno)); @@@ -634,8 -633,9 +651,9 @@@ static int delete_pseudoref(const char int fd; unsigned char actual_old_sha1[20]; - fd = hold_lock_file_for_update(&lock, filename, - LOCK_DIE_ON_ERROR); + fd = hold_lock_file_for_update_timeout( + &lock, filename, LOCK_DIE_ON_ERROR, + get_files_ref_lock_timeout_ms()); if (fd < 0) die_errno(_("Could not open '%s' for writing"), filename); if (read_ref(pseudoref, actual_old_sha1)) @@@ -836,7 -836,7 +854,7 @@@ int read_ref_at(const char *refname, un for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb); if (!cb.reccnt) { - if (flags & GET_SHA1_QUIETLY) + if (flags & GET_OID_QUIETLY) exit(128); else die("Log for %s is empty.", refname); @@@ -1178,7 -1178,7 +1196,7 @@@ int ref_is_hidden(const char *refname, const char *match = hide_refs->items[i].string; const char *subject; int neg = 0; - int len; + const char *p; if (*match == '!') { neg = 1; @@@ -1193,9 -1193,10 +1211,9 @@@ } /* refname can be NULL when namespaces are used. */ - if (!subject || !starts_with(subject, match)) - continue; - len = strlen(match); - if (!subject[len] || subject[len] == '/') + if (subject && + skip_prefix(subject, match, &p) && + (!*p || *p == '/')) return !neg; } return 0; diff --combined refs/files-backend.c index 5cca55510b,d611e0f7d7..fccbc24ac4 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@@ -3,7 -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" @@@ -16,6 -15,39 +16,6 @@@ struct ref_lock 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. @@@ -26,12 -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) { @@@ -58,8 -132,7 +58,8 @@@ static struct ref_store *files_ref_stor 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; } @@@ -102,6 -175,156 +102,6 @@@ static struct files_ref_store *files_do 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) @@@ -147,6 -370,70 +147,6 @@@ static void files_ref_path(struct files } } -/* - * 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 @@@ -269,6 -556,39 +269,6 @@@ static struct ref_cache *get_loose_ref_ 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) @@@ -312,8 -632,7 +312,8 @@@ 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; } @@@ -352,8 -671,7 +352,8 @@@ * 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; } @@@ -537,7 -855,9 +537,9 @@@ retry 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 @@@ -632,11 -952,11 +634,11 @@@ /* * 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; } @@@ -683,9 -1003,15 +685,9 @@@ static int files_peel_ref(struct ref_st * 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); } @@@ -693,6 -1019,7 +695,6 @@@ struct files_ref_iterator { struct ref_iterator base; - struct packed_ref_cache *packed_ref_cache; struct ref_iterator *iter0; unsigned int flags; }; @@@ -745,6 -1072,7 +747,6 @@@ static int files_ref_iterator_abort(str 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; } @@@ -786,28 -1114,18 +788,28 @@@ static struct ref_iterator *files_ref_i * (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; @@@ -865,7 -1183,9 +867,9 @@@ static int create_reflock(const char *p { 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; } /* @@@ -939,7 -1259,7 +943,7 @@@ static struct ref_lock *lock_ref_sha1_b * 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; @@@ -971,6 -1291,124 +975,6 @@@ 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]; @@@ -1093,11 -1531,12 +1097,11 @@@ static int files_pack_refs(struct ref_s 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; - 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) { @@@ -1106,6 -1545,8 +1110,6 @@@ * 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; @@@ -1116,7 -1557,17 +1120,7 @@@ * we don't copy the peeled status, because we want it * to be re-peeled. */ - 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); + add_packed_ref(refs->packed_ref_store, iter->refname, iter->oid); /* Schedule the loose reference for pruning if requested. */ if ((flags & PACK_REFS_PRUNE)) { @@@ -1130,15 -1581,69 +1134,15 @@@ if (ok != ITER_DONE) die("error while iterating over references"); - if (commit_packed_refs(refs)) - die_errno("unable to overwrite old ref-pack file"); + if (commit_packed_refs(refs->packed_ref_store, &err)) + die("unable to overwrite old ref-pack file: %s", err.buf); + packed_refs_unlock(refs->packed_ref_store); prune_refs(refs, refs_to_prune); + strbuf_release(&err); 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; - } - } - - /* Avoid locking if we have nothing to do */ - if (!needs_repacking) - return 0; /* no refname exists in packed refs */ - - if (lock_packed_refs(refs, 0)) { - unable_to_lock_message(files_packed_refs_path(refs), errno, err); - return -1; - } - packed = get_packed_refs(refs); - - /* 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; -} - static int files_delete_refs(struct ref_store *ref_store, const char *msg, struct string_list *refnames, unsigned int flags) { @@@ -1150,16 -1655,24 +1154,16 @@@ 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 (repack_without_refs(refs->packed_ref_store, refnames, &err)) { + 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; @@@ -1167,24 -1680,9 +1171,24 @@@ 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; } /* @@@ -2576,19 -3074,11 +2580,19 @@@ static int files_transaction_finish(str } } - if (repack_without_refs(refs, &refs_to_delete, err)) { + if (packed_refs_lock(refs->packed_ref_store, 0, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } + if (repack_without_refs(refs->packed_ref_store, &refs_to_delete, err)) { + ret = TRANSACTION_GENERIC_ERROR; + packed_refs_unlock(refs->packed_ref_store); + goto cleanup; + } + + packed_refs_unlock(refs->packed_ref_store); + /* Delete the reflogs of any references that were deleted: */ for_each_string_list_item(ref_to_delete, &refs_to_delete) { strbuf_reset(&sb); @@@ -2695,7 -3185,9 +2699,7 @@@ static int files_initial_transaction_co } } - 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; } @@@ -2705,17 -3197,18 +2709,17 @@@ if ((update->flags & REF_HAVE_NEW) && !is_null_oid(&update->new_oid)) - add_packed_ref(refs, update->refname, + add_packed_ref(refs->packed_ref_store, update->refname, &update->new_oid); } - if (commit_packed_refs(refs)) { - strbuf_addf(err, "unable to commit packed-refs file: %s", - strerror(errno)); + if (commit_packed_refs(refs->packed_ref_store, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } cleanup: + packed_refs_unlock(refs->packed_ref_store); transaction->state = REF_TRANSACTION_CLOSED; string_list_clear(&affected_refnames, 0); return ret; diff --combined refs/refs-internal.h index 4789106fc0,9977fea98b..b02dc5a7e3 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@@ -61,6 -61,12 +61,12 @@@ */ #define REF_DELETED_LOOSE 0x200 + /* + * Return the length of time to retry acquiring a loose reference lock + * before giving up, in milliseconds: + */ + long get_files_ref_lock_timeout_ms(void); + /* * Return true iff refname is minimally safe. "Safe" here means that * deleting a loose reference by this name will not do any damage, for @@@ -77,15 -83,6 +83,15 @@@ */ int refname_is_safe(const char *refname); +/* + * Helper function: 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. + */ +int ref_resolves_to_object(const char *refname, + const struct object_id *oid, + unsigned int flags); + enum peel_status { /* object was peeled successfully: */ PEEL_PEELED = 0, @@@ -664,7 -661,6 +670,7 @@@ struct ref_storage_be }; extern struct ref_storage_be refs_be_files; +extern struct ref_storage_be refs_be_packed; /* * A representation of the reference store for the main repository or