[PATCH v2 23/32] prune: strategies for linked checkouts
(alias R=$GIT_COMMON_DIR/worktrees/<id>)
- linked checkouts are supposed to keep its location in $R/gitdir up
to date. The use case is auto fixup after a manual checkout move.
- linked checkouts are supposed to update mtime of $R/gitdir. If
$R/gitdir's mtime is older than a limit, and it points to nowhere,
worktrees/<id> is to be pruned.
- If $R/locked exists, worktrees/<id> is not supposed to be pruned. If
$R/locked exists and $R/gitdir's mtime is older than a really long
limit, warn about old unused repo.
- "git checkout --to" is supposed to make a hard link named $R/link
pointing to the .git file on supported file systems to help detect
the user manually deleting the checkout. If $R/link exists and its
link count is greated than 1, the repo is kept.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
Documentation/git-checkout.txt | 18 ++++++
Documentation/git-prune.txt | 3 +
Documentation/gitrepository-layout.txt | 19 ++++++
builtin/checkout.c | 19 +++++-
builtin/prune.c | 95 ++++++++++++++++++++++++++++++
setup.c | 13 ++++
t/t2026-prune-linked-checkouts.sh (new +x) | 84 ++++++++++++++++++++++++++
7 files changed, 249 insertions(+), 2 deletions(-)
create mode 100755 t/t2026-prune-linked-checkouts.sh
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index bd0fc1d..a29748e 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -431,6 +431,24 @@ thumb is do not make any assumption about whether a path belongs to
$GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
+When you are done, simply deleting the linked working directory would
+suffice. $GIT_DIR/worktrees can be cleaned up using `git prune
+--worktrees`.
+
+After you move a linked working directory to another file system, or
+on a file system that does not support hard link, execute any git
+command (e.g. `git status`) in the new working directory so that it
+could update its location in $GIT_DIR/worktrees and not be
+accidentally pruned.
+
+To stop `git prune --worktrees` from deleting a specific working
+directory (e.g. because it's on a portable device), you could add the
+file 'locked' to $GIT_DIR/worktrees. For example, if `.git` file of
+the new working directory points to `/path/main/worktrees/test-next`,
+the full path of the 'locked' file would be
+`/path/main/worktrees/test-next/locked`. See
+linkgit:gitrepository-layout[5] for details.
+
EXAMPLES
--------
diff --git a/Documentation/git-prune.txt b/Documentation/git-prune.txt
index 7a493c8..a0ea381 100644
--- a/Documentation/git-prune.txt
+++ b/Documentation/git-prune.txt
@@ -48,6 +48,9 @@ OPTIONS
--expire <time>::
Only expire loose objects older than <time>.
+--worktrees::
+ Prune dead worktree information in $GIT_DIR/worktrees.
+
<head>...::
In addition to objects
reachable from any of our references, keep objects
diff --git a/Documentation/gitrepository-layout.txt b/Documentation/gitrepository-layout.txt
index a82780c..5ceff51 100644
--- a/Documentation/gitrepository-layout.txt
+++ b/Documentation/gitrepository-layout.txt
@@ -255,6 +255,25 @@ worktrees::
$GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/worktrees" will be
used instead.
+worktrees/<id>/gitdir::
+ A text file containing the absolute path back to the .git file
+ that points to here. This is used to check if the linked
+ repository has been manually removed and there is no need to
+ keep this directory any more. mtime of this file should be
+ updated every time the linked repository is accessed.
+
+worktrees/<id>/locked::
+ If this file exists, the linked repository may be on a
+ portable device and not available. It does not mean that the
+ linked repository is gone and `worktrees/<id>` could be
+ removed. The file's content contains a reason string on why
+ the repository is locked.
+
+worktrees/<id>/link::
+ If this file exists, it is a hard link to the linked .git
+ file. It is used to detect if the linked repository is
+ manually removed.
+
SEE ALSO
--------
linkgit:git-init[1],
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 1868f69..b5ddf88 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -822,7 +822,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
const char *path = opts->new_worktree, *name;
struct stat st;
struct child_process cp;
- int counter = 0, len;
+ int counter = 0, len, ret;
if (!new->commit)
die(_("no branch specified"));
@@ -853,11 +853,21 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
if (mkdir(sb_repo.buf, 0777))
die_errno(_("could not create directory of '%s'"), sb_repo.buf);
+ /*
+ * lock the incomplete repo so prune won't delete it, unlock
+ * after the preparation is over.
+ */
+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+ write_file(sb.buf, 1, "initializing\n");
+
strbuf_addf(&sb_git, "%s/.git", path);
if (safe_create_leading_directories_const(sb_git.buf))
die_errno(_("could not create leading directories of '%s'"),
sb_git.buf);
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
+ write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
real_path(get_git_common_dir()), name);
/*
@@ -866,6 +876,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
* value would do because this value will be ignored and
* replaced at the next (real) checkout.
*/
+ strbuf_reset(&sb);
strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1));
strbuf_reset(&sb);
@@ -881,7 +892,11 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
memset(&cp, 0, sizeof(cp));
cp.git_cmd = 1;
cp.argv = opts->saved_argv;
- return run_command(&cp);
+ ret = run_command(&cp);
+ strbuf_reset(&sb);
+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
+ unlink_or_warn(sb.buf);
+ return ret;
}
static int git_checkout_config(const char *var, const char *value, void *cb)
diff --git a/builtin/prune.c b/builtin/prune.c
index 144a3bd..cf56110 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -112,6 +112,91 @@ static void prune_object_dir(const char *path)
}
}
+static int prune_worktree(const char *id, struct strbuf *reason)
+{
+ struct stat st;
+ char *path;
+ int fd, len;
+
+ if (!is_directory(git_path("worktrees/%s", id))) {
+ strbuf_addf(reason, _("Removing worktrees/%s: not a valid directory"), id);
+ return 1;
+ }
+ if (file_exists(git_path("worktrees/%s/locked", id)))
+ return 0;
+ if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
+ strbuf_addf(reason, _("Removing worktrees/%s: gitdir file does not exist"), id);
+ return 1;
+ }
+ fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
+ if (fd < 0) {
+ strbuf_addf(reason, _("Removing worktrees/%s: unable to read gitdir file (%s)"),
+ id, strerror(errno));
+ return 1;
+ }
+ len = st.st_size;
+ path = xmalloc(len + 1);
+ read_in_full(fd, path, len);
+ close(fd);
+ while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
+ len--;
+ if (!len) {
+ strbuf_addf(reason, _("Removing worktrees/%s: invalid gitdir file"), id);
+ free(path);
+ return 1;
+ }
+ path[len] = '\0';
+ if (!file_exists(path)) {
+ struct stat st_link;
+ free(path);
+ /*
+ * the repo is moved manually and has not been
+ * accessed since?
+ */
+ if (!stat(git_path("worktrees/%s/link", id), &st_link) &&
+ st_link.st_nlink > 1)
+ return 0;
+ strbuf_addf(reason, _("Removing worktrees/%s: gitdir file points to non-existent location"), id);
+ return 1;
+ }
+ free(path);
+ return st.st_mtime <= expire;
+}
+
+static void prune_worktrees(void)
+{
+ struct strbuf reason = STRBUF_INIT;
+ struct strbuf path = STRBUF_INIT;
+ DIR *dir = opendir(git_path("worktrees"));
+ struct dirent *d;
+ int ret;
+ if (!dir)
+ return;
+ while ((d = readdir(dir)) != NULL) {
+ if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+ continue;
+ strbuf_reset(&reason);
+ if (!prune_worktree(d->d_name, &reason))
+ continue;
+ if (show_only || verbose)
+ printf("%s\n", reason.buf);
+ if (show_only)
+ continue;
+ strbuf_reset(&path);
+ strbuf_addstr(&path, git_path("worktrees/%s", d->d_name));
+ ret = remove_dir_recursively(&path, 0);
+ if (ret < 0 && errno == ENOTDIR)
+ ret = unlink(path.buf);
+ if (ret)
+ error(_("failed to remove: %s"), strerror(errno));
+ }
+ closedir(dir);
+ if (!show_only)
+ rmdir(git_path("worktrees"));
+ strbuf_release(&reason);
+ strbuf_release(&path);
+}
+
/*
* Write errors (particularly out of space) can result in
* failed temporary packs (and more rarely indexes and other
@@ -138,10 +223,12 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
{
struct rev_info revs;
struct progress *progress = NULL;
+ int do_prune_worktrees = 0;
const struct option options[] = {
OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
OPT__VERBOSE(&verbose, N_("report pruned objects")),
OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
+ OPT_BOOL(0, "worktrees", &do_prune_worktrees, N_("prune .git/worktrees")),
OPT_EXPIRY_DATE(0, "expire", &expire,
N_("expire objects older than <time>")),
OPT_END()
@@ -154,6 +241,14 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
init_revisions(&revs, prefix);
argc = parse_options(argc, argv, prefix, options, prune_usage, 0);
+
+ if (do_prune_worktrees) {
+ if (argc)
+ die(_("--worktrees does not take extra arguments"));
+ prune_worktrees();
+ return 0;
+ }
+
while (argc--) {
unsigned char sha1[20];
const char *name = *argv++;
diff --git a/setup.c b/setup.c
index 8f90bc3..da2d669 100644
--- a/setup.c
+++ b/setup.c
@@ -390,6 +390,17 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
return ret;
}
+static void update_linked_gitdir(const char *gitfile, const char *gitdir)
+{
+ struct strbuf path = STRBUF_INIT;
+ struct stat st;
+
+ strbuf_addf(&path, "%s/gitfile", gitdir);
+ if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
+ write_file(path.buf, 0, "%s\n", gitfile);
+ strbuf_release(&path);
+}
+
/*
* Try to read the location of the git directory from the .git file,
* return path to git directory if found.
@@ -438,6 +449,8 @@ const char *read_gitfile(const char *path)
if (!is_git_directory(dir))
die("Not a git repository: %s", dir);
+
+ update_linked_gitdir(path, dir);
path = real_path(dir);
free(buf);
diff --git a/t/t2026-prune-linked-checkouts.sh b/t/t2026-prune-linked-checkouts.sh
new file mode 100755
index 0000000..3622800
--- /dev/null
+++ b/t/t2026-prune-linked-checkouts.sh
@@ -0,0 +1,84 @@
+#!/bin/sh
+
+test_description='prune $GIT_DIR/worktrees'
+
+. ./test-lib.sh
+
+test_expect_success 'prune --worktrees on normal repo' '
+ git prune --worktrees &&
+ test_must_fail git prune --worktrees abc
+'
+
+test_expect_success 'prune files inside $GIT_DIR/worktrees' '
+ mkdir .git/worktrees &&
+ : >.git/worktrees/abc &&
+ git prune --worktrees --verbose >actual &&
+ cat >expect <<EOF &&
+Removing worktrees/abc: not a valid directory
+EOF
+ test_i18ncmp expect actual &&
+ ! test -f .git/worktrees/abc &&
+ ! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories without gitdir' '
+ mkdir -p .git/worktrees/def/abc &&
+ : >.git/worktrees/def/def &&
+ cat >expect <<EOF &&
+Removing worktrees/def: gitdir file does not exist
+EOF
+ git prune --worktrees --verbose >actual &&
+ test_i18ncmp expect actual &&
+ ! test -d .git/worktrees/def &&
+ ! test -d .git/worktrees
+'
+
+test_expect_success POSIXPERM 'prune directories with unreadable gitdir' '
+ mkdir -p .git/worktrees/def/abc &&
+ : >.git/worktrees/def/def &&
+ : >.git/worktrees/def/gitdir &&
+ chmod u-r .git/worktrees/def/gitdir &&
+ git prune --worktrees --verbose >actual &&
+ test_i18ngrep "Removing worktrees/def: unable to read gitdir file" actual &&
+ ! test -d .git/worktrees/def &&
+ ! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories with invalid gitdir' '
+ mkdir -p .git/worktrees/def/abc &&
+ : >.git/worktrees/def/def &&
+ : >.git/worktrees/def/gitdir &&
+ git prune --worktrees --verbose >actual &&
+ test_i18ngrep "Removing worktrees/def: invalid gitdir file" actual &&
+ ! test -d .git/worktrees/def &&
+ ! test -d .git/worktrees
+'
+
+test_expect_success 'prune directories with gitdir pointing to nowhere' '
+ mkdir -p .git/worktrees/def/abc &&
+ : >.git/worktrees/def/def &&
+ echo "$TRASH_DIRECTORY"/nowhere >.git/worktrees/def/gitdir &&
+ git prune --worktrees --verbose >actual &&
+ test_i18ngrep "Removing worktrees/def: gitdir file points to non-existent location" actual &&
+ ! test -d .git/worktrees/def &&
+ ! test -d .git/worktrees
+'
+
+test_expect_success 'not prune locked checkout' '
+ test_when_finished rm -r .git/worktrees
+ mkdir -p .git/worktrees/ghi &&
+ : >.git/worktrees/ghi/locked &&
+ git prune --worktrees &&
+ test -d .git/worktrees/ghi
+'
+
+test_expect_success 'not prune recent checkouts' '
+ test_when_finished rm -r .git/worktrees
+ mkdir zz &&
+ mkdir -p .git/worktrees/jlm &&
+ echo "$TRASH_DIRECTORY"/zz >.git/worktrees/jlm/gitdir &&
+ git prune --worktrees --verbose --expire=2.days.ago &&
+ test -d .git/worktrees/jlm
+'
+
+test_done
--
2.1.0.rc0.78.gc0d8480
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>