diff options
Diffstat (limited to 'refs')
| -rw-r--r-- | refs/files-backend.c | 585 | ||||
| -rw-r--r-- | refs/refs-internal.h | 15 |
2 files changed, 263 insertions, 337 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c index de9af1615c..1f38076411 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -513,9 +513,6 @@ static void sort_ref_dir(struct ref_dir *dir) dir->sorted = dir->nr = i; } -/* Include broken references in a do_for_each_ref*() iteration: */ -#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 - /* * Return true iff the reference described by entry can be resolved to * an object in the database. Emit a warning if the referred-to @@ -1272,8 +1269,6 @@ static struct ref_dir *get_loose_refs(struct ref_cache *refs) return get_ref_dir(refs->loose); } -/* We allow "recursive" symbolic refs. Only within reason, though */ -#define MAXDEPTH 5 #define MAXREFLEN (1024) /* @@ -1303,7 +1298,7 @@ static int resolve_gitlink_ref_recursive(struct ref_cache *refs, char buffer[128], *p; char *path; - if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN) + if (recursion > SYMREF_MAXDEPTH || strlen(refname) > MAXREFLEN) return -1; path = *refs->name ? git_pathdup_submodule(refs->name, "%s", refname) @@ -1371,13 +1366,11 @@ static struct ref_entry *get_packed_ref(const char *refname) } /* - * A loose ref file doesn't exist; check for a packed ref. The - * options are forwarded from resolve_safe_unsafe(). + * A loose ref file doesn't exist; check for a packed ref. */ static int resolve_missing_loose_ref(const char *refname, - int resolve_flags, unsigned char *sha1, - int *flags) + unsigned int *flags) { struct ref_entry *entry; @@ -1388,205 +1381,158 @@ static int resolve_missing_loose_ref(const char *refname, entry = get_packed_ref(refname); if (entry) { hashcpy(sha1, entry->u.value.oid.hash); - if (flags) - *flags |= REF_ISPACKED; - return 0; - } - /* The reference is not a packed reference, either. */ - if (resolve_flags & RESOLVE_REF_READING) { - errno = ENOENT; - return -1; - } else { - hashclr(sha1); + *flags |= REF_ISPACKED; return 0; } + /* refname is not a packed reference. */ + return -1; } -/* This function needs to return a meaningful errno on failure */ -static const char *resolve_ref_1(const char *refname, - int resolve_flags, - unsigned char *sha1, - int *flags, - struct strbuf *sb_refname, - struct strbuf *sb_path, - struct strbuf *sb_contents) +/* + * Read a raw ref from the filesystem or packed refs file. + * + * If the ref is a sha1, fill in sha1 and return 0. + * + * If the ref is symbolic, fill in *symref with the referrent + * (e.g. "refs/heads/master") and return 0. The caller is responsible + * for validating the referrent. Set REF_ISSYMREF in flags. + * + * If the ref doesn't exist, set errno to ENOENT and return -1. + * + * If the ref exists but is neither a symbolic ref nor a sha1, it is + * broken. Set REF_ISBROKEN in flags, set errno to EINVAL, and return + * -1. + * + * If there is another error reading the ref, set errno appropriately and + * return -1. + * + * Backend-specific flags might be set in flags as well, regardless of + * outcome. + * + * sb_path is workspace: the caller should allocate and free it. + * + * It is OK for refname to point into symref. In this case: + * - if the function succeeds with REF_ISSYMREF, symref will be + * overwritten and the memory pointed to by refname might be changed + * or even freed. + * - in all other cases, symref will be untouched, and therefore + * refname will still be valid and unchanged. + */ +int read_raw_ref(const char *refname, unsigned char *sha1, + struct strbuf *symref, unsigned int *flags) { - int depth = MAXDEPTH; - int bad_name = 0; + struct strbuf sb_contents = STRBUF_INIT; + struct strbuf sb_path = STRBUF_INIT; + const char *path; + const char *buf; + struct stat st; + int fd; + int ret = -1; + int save_errno; - if (flags) - *flags = 0; + strbuf_reset(&sb_path); + strbuf_git_path(&sb_path, "%s", refname); + path = sb_path.buf; - if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { - if (flags) - *flags |= REF_BAD_NAME; +stat_ref: + /* + * 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(). + */ - if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || - !refname_is_safe(refname)) { - errno = EINVAL; - return NULL; + if (lstat(path, &st) < 0) { + if (errno != ENOENT) + goto out; + if (resolve_missing_loose_ref(refname, sha1, flags)) { + errno = ENOENT; + goto out; } - /* - * dwim_ref() uses REF_ISBROKEN to distinguish between - * missing refs and refs that were present but invalid, - * to complain about the latter to stderr. - * - * We don't know whether the ref exists, so don't set - * REF_ISBROKEN yet. - */ - bad_name = 1; + ret = 0; + goto out; } - for (;;) { - const char *path; - struct stat st; - char *buf; - int fd; - - if (--depth < 0) { - errno = ELOOP; - return NULL; - } - - strbuf_reset(sb_path); - strbuf_git_path(sb_path, "%s", refname); - path = sb_path->buf; - - /* - * 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) { - if (errno != ENOENT) - return NULL; - if (resolve_missing_loose_ref(refname, resolve_flags, - sha1, flags)) - return NULL; - if (bad_name) { - hashclr(sha1); - if (flags) - *flags |= REF_ISBROKEN; - } - return refname; - } - /* Follow "normalized" - ie "refs/.." symlinks by hand */ - if (S_ISLNK(st.st_mode)) { - strbuf_reset(sb_contents); - if (strbuf_readlink(sb_contents, path, 0) < 0) { - if (errno == ENOENT || errno == EINVAL) - /* inconsistent with lstat; retry */ - goto stat_ref; - else - return NULL; - } - if (starts_with(sb_contents->buf, "refs/") && - !check_refname_format(sb_contents->buf, 0)) { - strbuf_swap(sb_refname, sb_contents); - refname = sb_refname->buf; - if (flags) - *flags |= REF_ISSYMREF; - if (resolve_flags & RESOLVE_REF_NO_RECURSE) { - hashclr(sha1); - return refname; - } - continue; - } - } - - /* Is it a directory? */ - if (S_ISDIR(st.st_mode)) { - errno = EISDIR; - return NULL; - } - - /* - * Anything else, just open it and try to use it as - * a ref - */ - fd = open(path, O_RDONLY); - if (fd < 0) { - if (errno == ENOENT) + /* Follow "normalized" - ie "refs/.." symlinks by hand */ + if (S_ISLNK(st.st_mode)) { + strbuf_reset(&sb_contents); + if (strbuf_readlink(&sb_contents, path, 0) < 0) { + if (errno == ENOENT || errno == EINVAL) /* inconsistent with lstat; retry */ goto stat_ref; else - return NULL; + goto out; } - strbuf_reset(sb_contents); - if (strbuf_read(sb_contents, fd, 256) < 0) { - int save_errno = errno; - close(fd); - errno = save_errno; - return NULL; + if (starts_with(sb_contents.buf, "refs/") && + !check_refname_format(sb_contents.buf, 0)) { + strbuf_swap(&sb_contents, symref); + *flags |= REF_ISSYMREF; + ret = 0; + goto out; } - close(fd); - strbuf_rtrim(sb_contents); + } - /* - * Is it a symbolic ref? - */ - if (!starts_with(sb_contents->buf, "ref:")) { - /* - * Please note that FETCH_HEAD has a second - * line containing other data. - */ - if (get_sha1_hex(sb_contents->buf, sha1) || - (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) { - if (flags) - *flags |= REF_ISBROKEN; - errno = EINVAL; - return NULL; - } - if (bad_name) { - hashclr(sha1); - if (flags) - *flags |= REF_ISBROKEN; - } - return refname; - } - if (flags) - *flags |= REF_ISSYMREF; - buf = sb_contents->buf + 4; + /* Is it a directory? */ + if (S_ISDIR(st.st_mode)) { + errno = EISDIR; + goto out; + } + + /* + * Anything else, just open it and try to use it as + * a ref + */ + fd = open(path, O_RDONLY); + if (fd < 0) { + if (errno == ENOENT) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + goto out; + } + strbuf_reset(&sb_contents); + if (strbuf_read(&sb_contents, fd, 256) < 0) { + int save_errno = errno; + close(fd); + errno = save_errno; + goto out; + } + close(fd); + strbuf_rtrim(&sb_contents); + buf = sb_contents.buf; + if (starts_with(buf, "ref:")) { + buf += 4; while (isspace(*buf)) buf++; - strbuf_reset(sb_refname); - strbuf_addstr(sb_refname, buf); - refname = sb_refname->buf; - if (resolve_flags & RESOLVE_REF_NO_RECURSE) { - hashclr(sha1); - return refname; - } - if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { - if (flags) - *flags |= REF_ISBROKEN; - - if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || - !refname_is_safe(buf)) { - errno = EINVAL; - return NULL; - } - bad_name = 1; - } + + strbuf_reset(symref); + strbuf_addstr(symref, buf); + *flags |= REF_ISSYMREF; + ret = 0; + goto out; } -} -const char *resolve_ref_unsafe(const char *refname, int resolve_flags, - unsigned char *sha1, int *flags) -{ - static struct strbuf sb_refname = STRBUF_INIT; - struct strbuf sb_contents = STRBUF_INIT; - struct strbuf sb_path = STRBUF_INIT; - const char *ret; + /* + * Please note that FETCH_HEAD has additional + * data after the sha. + */ + if (get_sha1_hex(buf, sha1) || + (buf[40] != '\0' && !isspace(buf[40]))) { + *flags |= REF_ISBROKEN; + errno = EINVAL; + goto out; + } + + ret = 0; - ret = resolve_ref_1(refname, resolve_flags, sha1, flags, - &sb_refname, &sb_path, &sb_contents); +out: + save_errno = errno; strbuf_release(&sb_path); strbuf_release(&sb_contents); + errno = save_errno; return ret; } @@ -1727,10 +1673,13 @@ static int do_for_each_entry(struct ref_cache *refs, const char *base, * value, stop the iteration and return that value; otherwise, return * 0. */ -static int do_for_each_ref(struct ref_cache *refs, const char *base, - each_ref_fn fn, int trim, int flags, void *cb_data) +int do_for_each_ref(const char *submodule, const char *base, + each_ref_fn fn, int trim, int flags, void *cb_data) { struct ref_entry_cb data; + struct ref_cache *refs; + + refs = get_ref_cache(submodule); data.base = base; data.trim = trim; data.flags = flags; @@ -1745,86 +1694,6 @@ static int do_for_each_ref(struct ref_cache *refs, const char *base, return do_for_each_entry(refs, base, do_one_ref, &data); } -static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data) -{ - struct object_id oid; - int flag; - - if (submodule) { - if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0) - return fn("HEAD", &oid, 0, cb_data); - - return 0; - } - - if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag)) - return fn("HEAD", &oid, flag, cb_data); - - return 0; -} - -int head_ref(each_ref_fn fn, void *cb_data) -{ - return do_head_ref(NULL, fn, cb_data); -} - -int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return do_head_ref(submodule, fn, cb_data); -} - -int for_each_ref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data); -} - -int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data); -} - -int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data); -} - -int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken) -{ - unsigned int flag = 0; - - if (broken) - flag = DO_FOR_EACH_INCLUDE_BROKEN; - return do_for_each_ref(&ref_cache, prefix, fn, 0, flag, cb_data); -} - -int for_each_ref_in_submodule(const char *submodule, const char *prefix, - each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data); -} - -int for_each_replace_ref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, git_replace_ref_base, fn, - strlen(git_replace_ref_base), 0, cb_data); -} - -int for_each_namespaced_ref(each_ref_fn fn, void *cb_data) -{ - struct strbuf buf = STRBUF_INIT; - int ret; - strbuf_addf(&buf, "%srefs/", get_git_namespace()); - ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data); - strbuf_release(&buf); - return ret; -} - -int for_each_rawref(each_ref_fn fn, void *cb_data) -{ - return do_for_each_ref(&ref_cache, "", fn, 0, - DO_FOR_EACH_INCLUDE_BROKEN, cb_data); -} - static void unlock_ref(struct ref_lock *lock) { /* Do not free lock->lk -- atexit() still looks at them */ @@ -1850,12 +1719,17 @@ static int verify_lock(struct ref_lock *lock, if (read_ref_full(lock->ref_name, mustexist ? RESOLVE_REF_READING : 0, lock->old_oid.hash, NULL)) { - int save_errno = errno; - strbuf_addf(err, "can't verify ref %s", lock->ref_name); - errno = save_errno; - return -1; + if (old_sha1) { + int save_errno = errno; + strbuf_addf(err, "can't verify ref %s", lock->ref_name); + errno = save_errno; + return -1; + } else { + hashclr(lock->old_oid.hash); + return 0; + } } - if (hashcmp(lock->old_oid.hash, old_sha1)) { + if (old_sha1 && hashcmp(lock->old_oid.hash, old_sha1)) { strbuf_addf(err, "ref %s is at %s but expected %s", lock->ref_name, sha1_to_hex(lock->old_oid.hash), @@ -1892,7 +1766,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, const char *orig_refname = refname; struct ref_lock *lock; int last_errno = 0; - int type, lflags; + int type; + int lflags = 0; int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); int resolve_flags = 0; int attempts_remaining = 3; @@ -1903,10 +1778,11 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, if (mustexist) resolve_flags |= RESOLVE_REF_READING; - if (flags & REF_DELETING) { + if (flags & REF_DELETING) resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; - if (flags & REF_NODEREF) - resolve_flags |= RESOLVE_REF_NO_RECURSE; + if (flags & REF_NODEREF) { + resolve_flags |= RESOLVE_REF_NO_RECURSE; + lflags |= LOCK_NO_DEREF; } refname = resolve_ref_unsafe(refname, resolve_flags, @@ -1942,6 +1818,10 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, goto error_return; } + + if (flags & REF_NODEREF) + refname = orig_refname; + /* * If the ref did not exist and we are creating it, make sure * there is no existing packed ref whose name begins with our @@ -1957,11 +1837,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, lock->lk = xcalloc(1, sizeof(struct lock_file)); - lflags = 0; - if (flags & REF_NODEREF) { - refname = orig_refname; - lflags |= LOCK_NO_DEREF; - } lock->ref_name = xstrdup(refname); lock->orig_ref_name = xstrdup(orig_refname); strbuf_git_path(&ref_file, "%s", refname); @@ -1995,7 +1870,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, goto error_return; } } - if (old_sha1 && verify_lock(lock, old_sha1, mustexist, err)) { + if (verify_lock(lock, old_sha1, mustexist, err)) { last_errno = errno; goto error_return; } @@ -2820,73 +2695,108 @@ static int commit_ref_update(struct ref_lock *lock, return 0; } -int create_symref(const char *ref_target, const char *refs_heads_master, - const char *logmsg) +static int create_ref_symlink(struct ref_lock *lock, const char *target) { - char *lockpath = NULL; - char ref[1000]; - int fd, len, written; - char *git_HEAD = git_pathdup("%s", ref_target); - unsigned char old_sha1[20], new_sha1[20]; - struct strbuf err = STRBUF_INIT; - - if (logmsg && read_ref(ref_target, old_sha1)) - hashclr(old_sha1); - - if (safe_create_leading_directories(git_HEAD) < 0) - return error("unable to create directory for %s", git_HEAD); - + int ret = -1; #ifndef NO_SYMLINK_HEAD - if (prefer_symlink_refs) { - unlink(git_HEAD); - if (!symlink(refs_heads_master, git_HEAD)) - goto done; + char *ref_path = get_locked_file_path(lock->lk); + unlink(ref_path); + ret = symlink(target, ref_path); + free(ref_path); + + if (ret) fprintf(stderr, "no symlink - falling back to symbolic ref\n"); - } #endif + return ret; +} - len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); - if (sizeof(ref) <= len) { - error("refname too long: %s", refs_heads_master); - goto error_free_return; +static void update_symref_reflog(struct ref_lock *lock, const char *refname, + const char *target, const char *logmsg) +{ + struct strbuf err = STRBUF_INIT; + unsigned char new_sha1[20]; + if (logmsg && !read_ref(target, new_sha1) && + log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) { + error("%s", err.buf); + strbuf_release(&err); } - lockpath = mkpathdup("%s.lock", git_HEAD); - fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); - if (fd < 0) { - error("Unable to open %s for writing", lockpath); - goto error_free_return; - } - written = write_in_full(fd, ref, len); - if (close(fd) != 0 || written != len) { - error("Unable to write to %s", lockpath); - goto error_unlink_return; - } - if (rename(lockpath, git_HEAD) < 0) { - error("Unable to create %s", git_HEAD); - goto error_unlink_return; - } - if (adjust_shared_perm(git_HEAD)) { - error("Unable to fix permissions on %s", lockpath); - error_unlink_return: - unlink_or_warn(lockpath); - error_free_return: - free(lockpath); - free(git_HEAD); +} + +static int create_symref_locked(struct ref_lock *lock, const char *refname, + const char *target, const char *logmsg) +{ + if (prefer_symlink_refs && !create_ref_symlink(lock, target)) { + update_symref_reflog(lock, refname, target, logmsg); + return 0; + } + + if (!fdopen_lock_file(lock->lk, "w")) + return error("unable to fdopen %s: %s", + lock->lk->tempfile.filename.buf, strerror(errno)); + + update_symref_reflog(lock, refname, target, logmsg); + + /* no error check; commit_ref will check ferror */ + 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)); + return 0; +} + +int create_symref(const char *refname, const char *target, const char *logmsg) +{ + struct strbuf err = STRBUF_INIT; + struct ref_lock *lock; + int ret; + + lock = lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL, + &err); + if (!lock) { + error("%s", err.buf); + strbuf_release(&err); return -1; } - free(lockpath); -#ifndef NO_SYMLINK_HEAD - done: -#endif - if (logmsg && !read_ref(refs_heads_master, new_sha1) && - log_ref_write(ref_target, old_sha1, new_sha1, logmsg, 0, &err)) { + ret = create_symref_locked(lock, refname, target, logmsg); + unlock_ref(lock); + return ret; +} + +int set_worktree_head_symref(const char *gitdir, const char *target) +{ + static struct lock_file head_lock; + struct ref_lock *lock; + struct strbuf head_path = STRBUF_INIT; + const char *head_rel; + int ret; + + strbuf_addf(&head_path, "%s/HEAD", absolute_path(gitdir)); + if (hold_lock_file_for_update(&head_lock, head_path.buf, + LOCK_NO_DEREF) < 0) { + struct strbuf err = STRBUF_INIT; + unable_to_lock_message(head_path.buf, errno, &err); error("%s", err.buf); strbuf_release(&err); + strbuf_release(&head_path); + return -1; } - free(git_HEAD); - return 0; + /* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for + linked trees */ + head_rel = remove_leading_path(head_path.buf, + absolute_path(get_git_common_dir())); + /* to make use of create_symref_locked(), initialize ref_lock */ + lock = xcalloc(1, sizeof(struct ref_lock)); + lock->lk = &head_lock; + lock->ref_name = xstrdup(head_rel); + lock->orig_ref_name = xstrdup(head_rel); + + ret = create_symref_locked(lock, head_rel, target, NULL); + + unlock_ref(lock); /* will free lock */ + strbuf_release(&head_path); + return ret; } int reflog_exists(const char *refname) @@ -3440,7 +3350,8 @@ int reflog_expire(const char *refname, const unsigned char *sha1, * reference itself, plus we might need to update the * reference if --updateref was specified: */ - lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err); + lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF, + &type, &err); if (!lock) { error("cannot lock ref '%s': %s", refname, err.buf); strbuf_release(&err); diff --git a/refs/refs-internal.h b/refs/refs-internal.h index c7dded35f4..3a4f634cb4 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -197,4 +197,19 @@ const char *find_descendant_ref(const char *dirname, int rename_ref_available(const char *oldname, const char *newname); +/* We allow "recursive" symbolic refs. Only within reason, though */ +#define SYMREF_MAXDEPTH 5 + +/* Include broken references in a do_for_each_ref*() iteration: */ +#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 + +/* + * The common backend for the for_each_*ref* functions + */ +int do_for_each_ref(const char *submodule, const char *base, + each_ref_fn fn, int trim, int flags, void *cb_data); + +int read_raw_ref(const char *refname, unsigned char *sha1, + struct strbuf *symref, unsigned int *flags); + #endif /* REFS_REFS_INTERNAL_H */ |