git/worktree.c
Eric Sunshine b214ab5aa5 worktree: teach "repair" to fix outgoing links to worktrees
The .git/worktrees/<id>/gitdir file points at the location of a linked
worktree's .git file. Its content must be of the form
/path/to/worktree/.git (from which the location of the worktree itself
can be derived by stripping the "/.git" suffix). If the gitdir file is
deleted or becomes corrupted or outdated, then Git will be unable to
find the linked worktree. An easy way for the gitdir file to become
outdated is for the user to move the worktree manually (without using
"git worktree move"). Although it is possible to manually update the
gitdir file to reflect the new linked worktree location, doing so
requires a level of knowledge about worktree internals beyond what a
user should be expected to know offhand.

Therefore, teach "git worktree repair" how to repair broken or outdated
.git/worktrees/<id>/gitdir files automatically. (For this to work, the
command must either be invoked from within the worktree whose gitdir
file requires repair, or from within the main or any linked worktree by
providing the path of the broken worktree as an argument to "git
worktree repair".)

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-31 11:47:45 -07:00

709 lines
16 KiB
C

#include "cache.h"
#include "repository.h"
#include "refs.h"
#include "strbuf.h"
#include "worktree.h"
#include "dir.h"
#include "wt-status.h"
void free_worktrees(struct worktree **worktrees)
{
int i = 0;
for (i = 0; worktrees[i]; i++) {
free(worktrees[i]->path);
free(worktrees[i]->id);
free(worktrees[i]->head_ref);
free(worktrees[i]->lock_reason);
free(worktrees[i]);
}
free (worktrees);
}
/**
* Update head_sha1, head_ref and is_detached of the given worktree
*/
static void add_head_info(struct worktree *wt)
{
int flags;
const char *target;
target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
"HEAD",
0,
&wt->head_oid, &flags);
if (!target)
return;
if (flags & REF_ISSYMREF)
wt->head_ref = xstrdup(target);
else
wt->is_detached = 1;
}
/**
* get the main worktree
*/
static struct worktree *get_main_worktree(void)
{
struct worktree *worktree = NULL;
struct strbuf worktree_path = STRBUF_INIT;
strbuf_add_real_path(&worktree_path, get_git_common_dir());
strbuf_strip_suffix(&worktree_path, "/.git");
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
/*
* NEEDSWORK: If this function is called from a secondary worktree and
* config.worktree is present, is_bare_repository_cfg will reflect the
* contents of config.worktree, not the contents of the main worktree.
* This means that worktree->is_bare may be set to 0 even if the main
* worktree is configured to be bare.
*/
worktree->is_bare = (is_bare_repository_cfg == 1) ||
is_bare_repository();
add_head_info(worktree);
return worktree;
}
static struct worktree *get_linked_worktree(const char *id)
{
struct worktree *worktree = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf worktree_path = STRBUF_INIT;
if (!id)
die("Missing linked worktree name");
strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
/* invalid gitdir file */
goto done;
strbuf_rtrim(&worktree_path);
strbuf_strip_suffix(&worktree_path, "/.git");
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
worktree->id = xstrdup(id);
add_head_info(worktree);
done:
strbuf_release(&path);
strbuf_release(&worktree_path);
return worktree;
}
static void mark_current_worktree(struct worktree **worktrees)
{
char *git_dir = absolute_pathdup(get_git_dir());
int i;
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
const char *wt_git_dir = get_worktree_git_dir(wt);
if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
wt->is_current = 1;
break;
}
}
free(git_dir);
}
struct worktree **get_worktrees(void)
{
struct worktree **list = NULL;
struct strbuf path = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int counter = 0, alloc = 2;
ALLOC_ARRAY(list, alloc);
list[counter++] = get_main_worktree();
strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
dir = opendir(path.buf);
strbuf_release(&path);
if (dir) {
while ((d = readdir(dir)) != NULL) {
struct worktree *linked = NULL;
if (is_dot_or_dotdot(d->d_name))
continue;
if ((linked = get_linked_worktree(d->d_name))) {
ALLOC_GROW(list, counter + 1, alloc);
list[counter++] = linked;
}
}
closedir(dir);
}
ALLOC_GROW(list, counter + 1, alloc);
list[counter] = NULL;
mark_current_worktree(list);
return list;
}
const char *get_worktree_git_dir(const struct worktree *wt)
{
if (!wt)
return get_git_dir();
else if (!wt->id)
return get_git_common_dir();
else
return git_common_path("worktrees/%s", wt->id);
}
static struct worktree *find_worktree_by_suffix(struct worktree **list,
const char *suffix)
{
struct worktree *found = NULL;
int nr_found = 0, suffixlen;
suffixlen = strlen(suffix);
if (!suffixlen)
return NULL;
for (; *list && nr_found < 2; list++) {
const char *path = (*list)->path;
int pathlen = strlen(path);
int start = pathlen - suffixlen;
/* suffix must start at directory boundary */
if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
!fspathcmp(suffix, path + start)) {
found = *list;
nr_found++;
}
}
return nr_found == 1 ? found : NULL;
}
struct worktree *find_worktree(struct worktree **list,
const char *prefix,
const char *arg)
{
struct worktree *wt;
char *to_free = NULL;
if ((wt = find_worktree_by_suffix(list, arg)))
return wt;
if (prefix)
arg = to_free = prefix_filename(prefix, arg);
wt = find_worktree_by_path(list, arg);
free(to_free);
return wt;
}
struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
{
struct strbuf wt_path = STRBUF_INIT;
char *path = real_pathdup(p, 0);
if (!path)
return NULL;
for (; *list; list++) {
if (!strbuf_realpath(&wt_path, (*list)->path, 0))
continue;
if (!fspathcmp(path, wt_path.buf))
break;
}
free(path);
strbuf_release(&wt_path);
return *list;
}
int is_main_worktree(const struct worktree *wt)
{
return !wt->id;
}
const char *worktree_lock_reason(struct worktree *wt)
{
assert(!is_main_worktree(wt));
if (!wt->lock_reason_valid) {
struct strbuf path = STRBUF_INIT;
strbuf_addstr(&path, worktree_git_path(wt, "locked"));
if (file_exists(path.buf)) {
struct strbuf lock_reason = STRBUF_INIT;
if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
die_errno(_("failed to read '%s'"), path.buf);
strbuf_trim(&lock_reason);
wt->lock_reason = strbuf_detach(&lock_reason, NULL);
} else
wt->lock_reason = NULL;
wt->lock_reason_valid = 1;
strbuf_release(&path);
}
return wt->lock_reason;
}
/* convenient wrapper to deal with NULL strbuf */
static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
{
va_list params;
if (!buf)
return;
va_start(params, fmt);
strbuf_vaddf(buf, fmt, params);
va_end(params);
}
int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
unsigned flags)
{
struct strbuf wt_path = STRBUF_INIT;
struct strbuf realpath = STRBUF_INIT;
char *path = NULL;
int err, ret = -1;
strbuf_addf(&wt_path, "%s/.git", wt->path);
if (is_main_worktree(wt)) {
if (is_directory(wt_path.buf)) {
ret = 0;
goto done;
}
/*
* Main worktree using .git file to point to the
* repository would make it impossible to know where
* the actual worktree is if this function is executed
* from another worktree. No .git file support for now.
*/
strbuf_addf_gently(errmsg,
_("'%s' at main working tree is not the repository directory"),
wt_path.buf);
goto done;
}
/*
* Make sure "gitdir" file points to a real .git file and that
* file points back here.
*/
if (!is_absolute_path(wt->path)) {
strbuf_addf_gently(errmsg,
_("'%s' file does not contain absolute path to the working tree location"),
git_common_path("worktrees/%s/gitdir", wt->id));
goto done;
}
if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
!file_exists(wt->path)) {
ret = 0;
goto done;
}
if (!file_exists(wt_path.buf)) {
strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
goto done;
}
path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
if (!path) {
strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
wt_path.buf, err);
goto done;
}
strbuf_realpath(&realpath, git_common_path("worktrees/%s", wt->id), 1);
ret = fspathcmp(path, realpath.buf);
if (ret)
strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
wt->path, git_common_path("worktrees/%s", wt->id));
done:
free(path);
strbuf_release(&wt_path);
strbuf_release(&realpath);
return ret;
}
void update_worktree_location(struct worktree *wt, const char *path_)
{
struct strbuf path = STRBUF_INIT;
if (is_main_worktree(wt))
BUG("can't relocate main worktree");
strbuf_realpath(&path, path_, 1);
if (fspathcmp(wt->path, path.buf)) {
write_file(git_common_path("worktrees/%s/gitdir", wt->id),
"%s/.git", path.buf);
free(wt->path);
wt->path = strbuf_detach(&path, NULL);
}
strbuf_release(&path);
}
int is_worktree_being_rebased(const struct worktree *wt,
const char *target)
{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_rebase(wt, &state) &&
((state.rebase_in_progress ||
state.rebase_interactive_in_progress) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/")));
free(state.branch);
free(state.onto);
return found_rebase;
}
int is_worktree_being_bisected(const struct worktree *wt,
const char *target)
{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_bisect(wt, &state) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/"));
free(state.branch);
return found_rebase;
}
/*
* note: this function should be able to detect shared symref even if
* HEAD is temporarily detached (e.g. in the middle of rebase or
* bisect). New commands that do similar things should update this
* function as well.
*/
const struct worktree *find_shared_symref(const char *symref,
const char *target)
{
const struct worktree *existing = NULL;
static struct worktree **worktrees;
int i = 0;
if (worktrees)
free_worktrees(worktrees);
worktrees = get_worktrees();
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
const char *symref_target;
struct ref_store *refs;
int flags;
if (wt->is_bare)
continue;
if (wt->is_detached && !strcmp(symref, "HEAD")) {
if (is_worktree_being_rebased(wt, target)) {
existing = wt;
break;
}
if (is_worktree_being_bisected(wt, target)) {
existing = wt;
break;
}
}
refs = get_worktree_ref_store(wt);
symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
NULL, &flags);
if ((flags & REF_ISSYMREF) &&
symref_target && !strcmp(symref_target, target)) {
existing = wt;
break;
}
}
return existing;
}
int submodule_uses_worktrees(const char *path)
{
char *submodule_gitdir;
struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int ret = 0;
struct repository_format format = REPOSITORY_FORMAT_INIT;
submodule_gitdir = git_pathdup_submodule(path, "%s", "");
if (!submodule_gitdir)
return 0;
/* The env would be set for the superproject. */
get_common_dir_noenv(&sb, submodule_gitdir);
free(submodule_gitdir);
strbuf_addstr(&sb, "/config");
read_repository_format(&format, sb.buf);
if (verify_repository_format(&format, &err)) {
strbuf_release(&err);
strbuf_release(&sb);
clear_repository_format(&format);
return 1;
}
clear_repository_format(&format);
strbuf_release(&err);
/* Replace config by worktrees. */
strbuf_setlen(&sb, sb.len - strlen("config"));
strbuf_addstr(&sb, "worktrees");
/* See if there is any file inside the worktrees directory. */
dir = opendir(sb.buf);
strbuf_release(&sb);
if (!dir)
return 0;
while ((d = readdir(dir)) != NULL) {
if (is_dot_or_dotdot(d->d_name))
continue;
ret = 1;
break;
}
closedir(dir);
return ret;
}
int parse_worktree_ref(const char *worktree_ref, const char **name,
int *name_length, const char **ref)
{
if (skip_prefix(worktree_ref, "main-worktree/", &worktree_ref)) {
if (!*worktree_ref)
return -1;
if (name)
*name = NULL;
if (name_length)
*name_length = 0;
if (ref)
*ref = worktree_ref;
return 0;
}
if (skip_prefix(worktree_ref, "worktrees/", &worktree_ref)) {
const char *slash = strchr(worktree_ref, '/');
if (!slash || slash == worktree_ref || !slash[1])
return -1;
if (name)
*name = worktree_ref;
if (name_length)
*name_length = slash - worktree_ref;
if (ref)
*ref = slash + 1;
return 0;
}
return -1;
}
void strbuf_worktree_ref(const struct worktree *wt,
struct strbuf *sb,
const char *refname)
{
switch (ref_type(refname)) {
case REF_TYPE_PSEUDOREF:
case REF_TYPE_PER_WORKTREE:
if (wt && !wt->is_current) {
if (is_main_worktree(wt))
strbuf_addstr(sb, "main-worktree/");
else
strbuf_addf(sb, "worktrees/%s/", wt->id);
}
break;
case REF_TYPE_MAIN_PSEUDOREF:
case REF_TYPE_OTHER_PSEUDOREF:
break;
case REF_TYPE_NORMAL:
/*
* For shared refs, don't prefix worktrees/ or
* main-worktree/. It's not necessary and
* files-backend.c can't handle it anyway.
*/
break;
}
strbuf_addstr(sb, refname);
}
const char *worktree_ref(const struct worktree *wt, const char *refname)
{
static struct strbuf sb = STRBUF_INIT;
strbuf_reset(&sb);
strbuf_worktree_ref(wt, &sb, refname);
return sb.buf;
}
int other_head_refs(each_ref_fn fn, void *cb_data)
{
struct worktree **worktrees, **p;
int ret = 0;
worktrees = get_worktrees();
for (p = worktrees; *p; p++) {
struct worktree *wt = *p;
struct object_id oid;
int flag;
if (wt->is_current)
continue;
if (!refs_read_ref_full(get_main_ref_store(the_repository),
worktree_ref(wt, "HEAD"),
RESOLVE_REF_READING,
&oid, &flag))
ret = fn(worktree_ref(wt, "HEAD"), &oid, flag, cb_data);
if (ret)
break;
}
free_worktrees(worktrees);
return ret;
}
/*
* Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
* pointing at <repo>/worktrees/<id>.
*/
static void repair_gitfile(struct worktree *wt,
worktree_repair_fn fn, void *cb_data)
{
struct strbuf dotgit = STRBUF_INIT;
struct strbuf repo = STRBUF_INIT;
char *backlink;
const char *repair = NULL;
int err;
/* missing worktree can't be repaired */
if (!file_exists(wt->path))
return;
if (!is_directory(wt->path)) {
fn(1, wt->path, _("not a directory"), cb_data);
return;
}
strbuf_realpath(&repo, git_common_path("worktrees/%s", wt->id), 1);
strbuf_addf(&dotgit, "%s/.git", wt->path);
backlink = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
if (err == READ_GITFILE_ERR_NOT_A_FILE)
fn(1, wt->path, _(".git is not a file"), cb_data);
else if (err)
repair = _(".git file broken");
else if (fspathcmp(backlink, repo.buf))
repair = _(".git file incorrect");
if (repair) {
fn(0, wt->path, repair, cb_data);
write_file(dotgit.buf, "gitdir: %s", repo.buf);
}
free(backlink);
strbuf_release(&repo);
strbuf_release(&dotgit);
}
static void repair_noop(int iserr, const char *path, const char *msg,
void *cb_data)
{
/* nothing */
}
void repair_worktrees(worktree_repair_fn fn, void *cb_data)
{
struct worktree **worktrees = get_worktrees();
struct worktree **wt = worktrees + 1; /* +1 skips main worktree */
if (!fn)
fn = repair_noop;
for (; *wt; wt++)
repair_gitfile(*wt, fn, cb_data);
free_worktrees(worktrees);
}
static int is_main_worktree_path(const char *path)
{
struct strbuf target = STRBUF_INIT;
struct strbuf maindir = STRBUF_INIT;
int cmp;
strbuf_add_real_path(&target, path);
strbuf_strip_suffix(&target, "/.git");
strbuf_add_real_path(&maindir, get_git_common_dir());
strbuf_strip_suffix(&maindir, "/.git");
cmp = fspathcmp(maindir.buf, target.buf);
strbuf_release(&maindir);
strbuf_release(&target);
return !cmp;
}
/*
* Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
* the worktree's path.
*/
void repair_worktree_at_path(const char *path,
worktree_repair_fn fn, void *cb_data)
{
struct strbuf dotgit = STRBUF_INIT;
struct strbuf realdotgit = STRBUF_INIT;
struct strbuf gitdir = STRBUF_INIT;
struct strbuf olddotgit = STRBUF_INIT;
char *backlink = NULL;
const char *repair = NULL;
int err;
if (!fn)
fn = repair_noop;
if (is_main_worktree_path(path))
goto done;
strbuf_addf(&dotgit, "%s/.git", path);
if (!strbuf_realpath(&realdotgit, dotgit.buf, 0)) {
fn(1, path, _("not a valid path"), cb_data);
goto done;
}
backlink = xstrdup_or_null(read_gitfile_gently(realdotgit.buf, &err));
if (err == READ_GITFILE_ERR_NOT_A_FILE) {
fn(1, realdotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
goto done;
} else if (err) {
fn(1, realdotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
goto done;
}
strbuf_addf(&gitdir, "%s/gitdir", backlink);
if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
repair = _("gitdir unreadable");
else {
strbuf_rtrim(&olddotgit);
if (fspathcmp(olddotgit.buf, realdotgit.buf))
repair = _("gitdir incorrect");
}
if (repair) {
fn(0, gitdir.buf, repair, cb_data);
write_file(gitdir.buf, "%s", realdotgit.buf);
}
done:
free(backlink);
strbuf_release(&olddotgit);
strbuf_release(&gitdir);
strbuf_release(&realdotgit);
strbuf_release(&dotgit);
}