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 $R/link exists and its link count is greated than 1, the repo is kept. Helped-by: Marc Branchaud <marcnarc@xiplink.com> Helped-by: Eric Sunshine <sunshine@sunshineco.com> Helped-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Marc Branchaud <marcnarc@xiplink.com> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nguyễn Thái Ngọc Duy committed
Nov 30, 2014 at 15:24 UTC
23af91d102e1efaff33b77ab7746356835a3d600
7 files changed
+251
-2
Documentation/git-checkout.txt
+20
@@ -434,6 +434,26 @@ thumb is do not make any assumption about whether a path belongs to
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$GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
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inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
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+When you are done with a linked working tree you can simply delete it.
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+You can clean up any stale $GIT_DIR/worktrees entries via `git prune
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+--worktrees` in the main or any linked working tree.
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+
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+If you move a linked working directory to another file system, or
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+within a file system that does not support hard links, you need to run
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+at least one git command inside the linked working directory
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+(e.g. `git status`) in order to update its entry in $GIT_DIR/worktrees
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+so that it does not get automatically removed.
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+
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+To prevent `git prune --worktrees` from deleting a $GIT_DIR/worktrees
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+entry (which can be useful in some situations, such as when the
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+entry's working tree is stored on a portable device), add a file named
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+'locked' to the entry's directory. The file contains the reason in
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+plain text. For example, if a linked working tree's `.git` file points
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+to `/path/main/.git/worktrees/test-next` then a file named
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+`/path/main/.git/worktrees/test-next/locked` will prevent the
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+`test-next` entry from being pruned. See
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+linkgit:gitrepository-layout[5] for details.
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+
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EXAMPLES
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--------
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Documentation/git-prune.txt
+3
@@ -48,6 +48,9 @@ OPTIONS
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--expire <time>::
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Only expire loose objects older than <time>.
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+--worktrees::
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+ Prune dead working tree information in $GIT_DIR/worktrees.
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+
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<head>...::
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In addition to objects
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reachable from any of our references, keep objects
Documentation/gitrepository-layout.txt
+19
@@ -259,6 +259,25 @@ worktrees::
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$GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/worktrees" will be
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used instead.
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+worktrees/<id>/gitdir::
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+ A text file containing the absolute path back to the .git file
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+ that points to here. This is used to check if the linked
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+ repository has been manually removed and there is no need to
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+ keep this directory any more. mtime of this file should be
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+ updated every time the linked repository is accessed.
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+
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+worktrees/<id>/locked::
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+ If this file exists, the linked repository may be on a
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+ portable device and not available. It does not mean that the
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+ linked repository is gone and `worktrees/<id>` could be
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+ removed. The file's content contains a reason string on why
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+ the repository is locked.
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+
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+worktrees/<id>/link::
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+ If this file exists, it is a hard link to the linked .git
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+ file. It is used to detect if the linked repository is
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+ manually removed.
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+
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SEE ALSO
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--------
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linkgit:git-init[1],
builtin/checkout.c
+17
-2
@@ -826,7 +826,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
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const char *path = opts->new_worktree, *name;
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struct stat st;
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struct child_process cp;
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- int counter = 0, len;
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+ int counter = 0, len, ret;
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if (!new->commit)
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die(_("no branch specified"));
@@ -857,11 +857,21 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
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if (mkdir(sb_repo.buf, 0777))
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die_errno(_("could not create directory of '%s'"), sb_repo.buf);
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+ /*
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+ * lock the incomplete repo so prune won't delete it, unlock
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+ * after the preparation is over.
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+ */
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+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
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+ write_file(sb.buf, 1, "initializing\n");
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+
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strbuf_addf(&sb_git, "%s/.git", path);
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if (safe_create_leading_directories_const(sb_git.buf))
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die_errno(_("could not create leading directories of '%s'"),
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sb_git.buf);
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+ strbuf_reset(&sb);
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+ strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
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+ write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
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write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
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real_path(get_git_common_dir()), name);
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/*
@@ -870,6 +880,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
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* value would do because this value will be ignored and
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* replaced at the next (real) checkout.
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*/
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+ strbuf_reset(&sb);
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strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
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write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1));
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strbuf_reset(&sb);
@@ -885,7 +896,11 @@ static int prepare_linked_checkout(const struct checkout_opts *opts,
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memset(&cp, 0, sizeof(cp));
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cp.git_cmd = 1;
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cp.argv = opts->saved_argv;
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- return run_command(&cp);
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+ ret = run_command(&cp);
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+ strbuf_reset(&sb);
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+ strbuf_addf(&sb, "%s/locked", sb_repo.buf);
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+ unlink_or_warn(sb.buf);
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+ return ret;
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}
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static int git_checkout_config(const char *var, const char *value, void *cb)
builtin/prune.c
+95
@@ -76,6 +76,91 @@ static int prune_subdir(int nr, const char *path, void *data)
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return 0;
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}
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+static int prune_worktree(const char *id, struct strbuf *reason)
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+{
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+ struct stat st;
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+ char *path;
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+ int fd, len;
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+
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+ if (!is_directory(git_path("worktrees/%s", id))) {
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+ strbuf_addf(reason, _("Removing worktrees/%s: not a valid directory"), id);
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+ return 1;
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+ }
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+ if (file_exists(git_path("worktrees/%s/locked", id)))
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+ return 0;
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+ if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
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+ strbuf_addf(reason, _("Removing worktrees/%s: gitdir file does not exist"), id);
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+ return 1;
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+ }
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+ fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
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+ if (fd < 0) {
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+ strbuf_addf(reason, _("Removing worktrees/%s: unable to read gitdir file (%s)"),
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+ id, strerror(errno));
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+ return 1;
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+ }
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+ len = st.st_size;
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+ path = xmalloc(len + 1);
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+ read_in_full(fd, path, len);
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+ close(fd);
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+ while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
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+ len--;
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+ if (!len) {
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+ strbuf_addf(reason, _("Removing worktrees/%s: invalid gitdir file"), id);
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+ free(path);
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+ return 1;
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+ }
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+ path[len] = '\0';
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+ if (!file_exists(path)) {
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+ struct stat st_link;
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+ free(path);
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+ /*
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+ * the repo is moved manually and has not been
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+ * accessed since?
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+ */
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+ if (!stat(git_path("worktrees/%s/link", id), &st_link) &&
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+ st_link.st_nlink > 1)
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+ return 0;
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+ strbuf_addf(reason, _("Removing worktrees/%s: gitdir file points to non-existent location"), id);
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+ return 1;
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+ }
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+ free(path);
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+ return st.st_mtime <= expire;
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+}
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+
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+static void prune_worktrees(void)
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+{
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+ struct strbuf reason = STRBUF_INIT;
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+ struct strbuf path = STRBUF_INIT;
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+ DIR *dir = opendir(git_path("worktrees"));
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+ struct dirent *d;
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+ int ret;
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+ if (!dir)
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+ return;
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+ while ((d = readdir(dir)) != NULL) {
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+ if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
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+ continue;
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+ strbuf_reset(&reason);
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+ if (!prune_worktree(d->d_name, &reason))
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+ continue;
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+ if (show_only || verbose)
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+ printf("%s\n", reason.buf);
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+ if (show_only)
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+ continue;
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+ strbuf_reset(&path);
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+ strbuf_addstr(&path, git_path("worktrees/%s", d->d_name));
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+ ret = remove_dir_recursively(&path, 0);
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+ if (ret < 0 && errno == ENOTDIR)
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+ ret = unlink(path.buf);
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+ if (ret)
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+ error(_("failed to remove: %s"), strerror(errno));
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+ }
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+ closedir(dir);
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+ if (!show_only)
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+ rmdir(git_path("worktrees"));
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+ strbuf_release(&reason);
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+ strbuf_release(&path);
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+}
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+
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/*
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* Write errors (particularly out of space) can result in
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* failed temporary packs (and more rarely indexes and other
@@ -102,10 +187,12 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
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{
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struct rev_info revs;
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struct progress *progress = NULL;
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+ int do_prune_worktrees = 0;
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const struct option options[] = {
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OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
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OPT__VERBOSE(&verbose, N_("report pruned objects")),
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OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
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+ OPT_BOOL(0, "worktrees", &do_prune_worktrees, N_("prune .git/worktrees")),
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OPT_EXPIRY_DATE(0, "expire", &expire,
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N_("expire objects older than <time>")),
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OPT_END()
@@ -118,6 +205,14 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
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init_revisions(&revs, prefix);
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argc = parse_options(argc, argv, prefix, options, prune_usage, 0);
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+
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+ if (do_prune_worktrees) {
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+ if (argc)
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+ die(_("--worktrees does not take extra arguments"));
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+ prune_worktrees();
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+ return 0;
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+ }
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+
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while (argc--) {
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unsigned char sha1[20];
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const char *name = *argv++;
setup.c
+13
@@ -390,6 +390,17 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
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return ret;
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}
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+static void update_linked_gitdir(const char *gitfile, const char *gitdir)
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+{
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+ struct strbuf path = STRBUF_INIT;
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+ struct stat st;
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+
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+ strbuf_addf(&path, "%s/gitfile", gitdir);
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+ if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
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+ write_file(path.buf, 0, "%s\n", gitfile);
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+ strbuf_release(&path);
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+}
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+
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/*
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* Try to read the location of the git directory from the .git file,
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* return path to git directory if found.
@@ -438,6 +449,8 @@ const char *read_gitfile(const char *path)
449
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if (!is_git_directory(dir))
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die("Not a git repository: %s", dir);
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+
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+ update_linked_gitdir(path, dir);
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path = real_path(dir);
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456
free(buf);
t/t2026-prune-linked-checkouts.sh
new
+84
@@ -0,0 +1,84 @@
1
+#!/bin/sh
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+
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+test_description='prune $GIT_DIR/worktrees'
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+
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+. ./test-lib.sh
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+
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+test_expect_success 'prune --worktrees on normal repo' '
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+ git prune --worktrees &&
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+ test_must_fail git prune --worktrees abc
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+'
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+
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+test_expect_success 'prune files inside $GIT_DIR/worktrees' '
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+ mkdir .git/worktrees &&
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+ : >.git/worktrees/abc &&
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+ git prune --worktrees --verbose >actual &&
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+ cat >expect <<EOF &&
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+Removing worktrees/abc: not a valid directory
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+EOF
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+ test_i18ncmp expect actual &&
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+ ! test -f .git/worktrees/abc &&
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+ ! test -d .git/worktrees
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+'
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+
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+test_expect_success 'prune directories without gitdir' '
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+ mkdir -p .git/worktrees/def/abc &&
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+ : >.git/worktrees/def/def &&
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+ cat >expect <<EOF &&
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+Removing worktrees/def: gitdir file does not exist
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+EOF
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+ git prune --worktrees --verbose >actual &&
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+ test_i18ncmp expect actual &&
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+ ! test -d .git/worktrees/def &&
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+ ! test -d .git/worktrees
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+'
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+
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+test_expect_success POSIXPERM 'prune directories with unreadable gitdir' '
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+ mkdir -p .git/worktrees/def/abc &&
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+ : >.git/worktrees/def/def &&
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+ : >.git/worktrees/def/gitdir &&
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+ chmod u-r .git/worktrees/def/gitdir &&
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+ git prune --worktrees --verbose >actual &&
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+ test_i18ngrep "Removing worktrees/def: unable to read gitdir file" actual &&
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+ ! test -d .git/worktrees/def &&
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+ ! test -d .git/worktrees
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+'
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+
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+test_expect_success 'prune directories with invalid gitdir' '
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+ mkdir -p .git/worktrees/def/abc &&
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+ : >.git/worktrees/def/def &&
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+ : >.git/worktrees/def/gitdir &&
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+ git prune --worktrees --verbose >actual &&
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+ test_i18ngrep "Removing worktrees/def: invalid gitdir file" actual &&
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+ ! test -d .git/worktrees/def &&
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+ ! test -d .git/worktrees
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+'
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+
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+test_expect_success 'prune directories with gitdir pointing to nowhere' '
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+ mkdir -p .git/worktrees/def/abc &&
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+ : >.git/worktrees/def/def &&
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+ echo "$(pwd)"/nowhere >.git/worktrees/def/gitdir &&
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+ git prune --worktrees --verbose >actual &&
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+ test_i18ngrep "Removing worktrees/def: gitdir file points to non-existent location" actual &&
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+ ! test -d .git/worktrees/def &&
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+ ! test -d .git/worktrees
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+'
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+
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+test_expect_success 'not prune locked checkout' '
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+ test_when_finished rm -r .git/worktrees
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+ mkdir -p .git/worktrees/ghi &&
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+ : >.git/worktrees/ghi/locked &&
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+ git prune --worktrees &&
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+ test -d .git/worktrees/ghi
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+'
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+
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+test_expect_success 'not prune recent checkouts' '
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+ test_when_finished rm -r .git/worktrees
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+ mkdir zz &&
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+ mkdir -p .git/worktrees/jlm &&
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+ echo "$(pwd)"/zz >.git/worktrees/jlm/gitdir &&
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+ git prune --worktrees --verbose --expire=2.days.ago &&
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+ test -d .git/worktrees/jlm
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+'
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+
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+test_done