From patchwork Tue Mar 1 18:43:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Hostetler X-Patchwork-Id: 12765069 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 737AAC433F5 for ; Tue, 1 Mar 2022 18:44:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237175AbiCASph (ORCPT ); Tue, 1 Mar 2022 13:45:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237058AbiCASox (ORCPT ); Tue, 1 Mar 2022 13:44:53 -0500 Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE30E5D5E6 for ; Tue, 1 Mar 2022 10:43:46 -0800 (PST) Received: by mail-wr1-x432.google.com with SMTP id b5so22003224wrr.2 for ; Tue, 01 Mar 2022 10:43:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=RT2c3XBUF0c1NpErSfda3qkboOoI55MdbTGZDgFpnAM=; b=CBGXBaEPWYYEq9U4A3a17r5F+dkujwfe/yE79CZTdHHgVQEQjL3HJl31znZMtpWXU5 FefeimKxDXsI8njWIGOJ159FkGh+IMzuthxa4d0wSoMBAtAPlJLAMa/os0X3cE+ZwVkb PmfXCDiQeYzoJzlQCX3AJ2BzLQqsa7BmNUdwOFVvnWruZtuF4DDPxQazAP9+NnFHnVF1 9xU3o95i+WVODgGQ3BuOZVznosnZLxtG2f3t05cshHQJ/J5WHYdiaEsfQrXkkdkK0nOb dA5QaGMVxl7Y3g92/HvbPKVS0PW1mLHi/FQYBEDcYSVNcPVTbT7K2WOAYkW3sBKSqHmQ AQwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=RT2c3XBUF0c1NpErSfda3qkboOoI55MdbTGZDgFpnAM=; b=DoaL3yRiRM5isKhwRDm/7Xa54v/IL/Sjnnwf5Qk5TiVPuYc5Zj4hg3tfPfoeEOrqn5 T7NiTYOuwWLyygXo1Ts2ytumeZNKJNI3rTFUsSNp6DOppUD5iLZuuFLCsS4o06NkBbqN 5Fsm+3moVzTA3Fd4SrPnoTIGx9QYqgftWhs2qOko0yUascPuQNO6rgKcYwDLNpyteJPb mZNWgavNwOzGUwF3L6gopM8uxxsn7va9femBlW0CUVLp5XhC07c4z+JVood9QnGEgULX SviZvrwuZwrztU4H+ZM2JVz/bz09MKZKXG5mAYzNwLtbXvop3FcdfyuaU/nt6QhhwuAZ v9qA== X-Gm-Message-State: AOAM533HYQBhERO0RjuRllAUYaoU1epXdBaZvPXr3haAzcDnEPC2G84I w00CWdBArYOxad18rxl/QlG60JBULQo= X-Google-Smtp-Source: ABdhPJyBSXQiLJ+RmEtCBrEyhJcU4kj4O3hL87SDvORsmTuI12BjOkPvvoTOrxflmUih4wWIRo4Lmg== X-Received: by 2002:a5d:43cf:0:b0:1f0:2250:585d with SMTP id v15-20020a5d43cf000000b001f02250585dmr2046164wrr.194.1646160225046; Tue, 01 Mar 2022 10:43:45 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id n7-20020a5d51c7000000b001a38105483dsm14373965wrv.24.2022.03.01.10.43.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Mar 2022 10:43:44 -0800 (PST) Message-Id: In-Reply-To: References: Date: Tue, 01 Mar 2022 18:43:14 +0000 Subject: [PATCH v6 12/30] fsmonitor--daemon: add pathname classification Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Bagas Sanjaya , =?utf-8?b?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason , Jeff Hostetler , Eric Sunshine , Johannes Schindelin , Tao Klerks , Jeff Hostetler , Jeff Hostetler Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Jeff Hostetler From: Jeff Hostetler Teach fsmonitor--daemon to classify relative and absolute pathnames and decide how they should be handled. This will be used by the platform-specific backend to respond to each filesystem event. When we register for filesystem notifications on a directory, we get events for everything (recursively) in the directory. We want to report to clients changes to tracked and untracked paths within the working directory proper. We do not want to report changes within the .git directory, for example. This classification will be used in a later commit by the different backends to classify paths as events are received. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano --- builtin/fsmonitor--daemon.c | 81 ++++++++++++++++++++++++++++++++++ fsmonitor--daemon.h | 87 +++++++++++++++++++++++++++++++++++++ 2 files changed, 168 insertions(+) diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c index 2f721aae016..cb126883832 100644 --- a/builtin/fsmonitor--daemon.c +++ b/builtin/fsmonitor--daemon.c @@ -134,6 +134,87 @@ static int handle_client(void *data, return result; } +#define FSMONITOR_COOKIE_PREFIX ".fsmonitor-daemon-" + +enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative( + const char *rel) +{ + if (fspathncmp(rel, ".git", 4)) + return IS_WORKDIR_PATH; + rel += 4; + + if (!*rel) + return IS_DOT_GIT; + if (*rel != '/') + return IS_WORKDIR_PATH; /* e.g. .gitignore */ + rel++; + + if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX, + strlen(FSMONITOR_COOKIE_PREFIX))) + return IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX; + + return IS_INSIDE_DOT_GIT; +} + +enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative( + const char *rel) +{ + if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX, + strlen(FSMONITOR_COOKIE_PREFIX))) + return IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX; + + return IS_INSIDE_GITDIR; +} + +static enum fsmonitor_path_type try_classify_workdir_abs_path( + struct fsmonitor_daemon_state *state, + const char *path) +{ + const char *rel; + + if (fspathncmp(path, state->path_worktree_watch.buf, + state->path_worktree_watch.len)) + return IS_OUTSIDE_CONE; + + rel = path + state->path_worktree_watch.len; + + if (!*rel) + return IS_WORKDIR_PATH; /* it is the root dir exactly */ + if (*rel != '/') + return IS_OUTSIDE_CONE; + rel++; + + return fsmonitor_classify_path_workdir_relative(rel); +} + +enum fsmonitor_path_type fsmonitor_classify_path_absolute( + struct fsmonitor_daemon_state *state, + const char *path) +{ + const char *rel; + enum fsmonitor_path_type t; + + t = try_classify_workdir_abs_path(state, path); + if (state->nr_paths_watching == 1) + return t; + if (t != IS_OUTSIDE_CONE) + return t; + + if (fspathncmp(path, state->path_gitdir_watch.buf, + state->path_gitdir_watch.len)) + return IS_OUTSIDE_CONE; + + rel = path + state->path_gitdir_watch.len; + + if (!*rel) + return IS_GITDIR; /* it is the exactly */ + if (*rel != '/') + return IS_OUTSIDE_CONE; + rel++; + + return fsmonitor_classify_path_gitdir_relative(rel); +} + static void *fsm_listen__thread_proc(void *_state) { struct fsmonitor_daemon_state *state = _state; diff --git a/fsmonitor--daemon.h b/fsmonitor--daemon.h index 3009c1a83de..8c3a71a48bd 100644 --- a/fsmonitor--daemon.h +++ b/fsmonitor--daemon.h @@ -30,5 +30,92 @@ struct fsmonitor_daemon_state { struct ipc_server_data *ipc_server_data; }; +/* + * Pathname classifications. + * + * The daemon classifies the pathnames that it receives from file + * system notification events into the following categories and uses + * that to decide whether clients are told about them. (And to watch + * for file system synchronization events.) + * + * The daemon only collects and reports on the set of modified paths + * within the working directory (proper). + * + * The client should only care about paths within the working + * directory proper (inside the working directory and not ".git" nor + * inside of ".git/"). That is, the client has read the index and is + * asking for a list of any paths in the working directory that have + * been modified since the last token. The client does not care about + * file system changes within the ".git/" directory (such as new loose + * objects or packfiles). So the client will only receive paths that + * are classified as IS_WORKDIR_PATH. + * + * Note that ".git" is usually a directory and is therefore inside + * the cone of the FS watch that we have on the working directory root, + * so we will also get FS events for disk activity on and within ".git/" + * that we need to respond to or filter from the client. + * + * But Git also allows ".git" to be a *file* that points to a GITDIR + * outside of the working directory. When this happens, we need to + * create FS watches on both the working directory root *and* on the + * (external) GITDIR root. (The latter is required because we put + * cookie files inside it and use them to sync with the FS event + * stream.) + * + * Note that in the context of this discussion, I'm using "GITDIR" + * to only mean an external GITDIR referenced by a ".git" file. + * + * The platform FS event backends will receive watch-specific + * relative paths (except for those OS's that always emit absolute + * paths). We use the following enum and routines to classify each + * path so that we know how to handle it. There is a slight asymmetry + * here because ".git/" is inside the working directory and the + * (external) GITDIR is not, and therefore how we handle events may + * vary slightly, so I have different enums for "IS...DOT_GIT..." and + * "IS...GITDIR...". + * + * The daemon uses the IS_DOT_GIT and IS_GITDIR internally to mean the + * exact ".git" file/directory or GITDIR directory. If the daemon + * receives a delete event for either of these paths, it will + * automatically shutdown, for example. + * + * Note that the daemon DOES NOT explicitly watch nor special case the + * index. The daemon does not read the index nor have any internal + * index-relative state, so there are no "IS...INDEX..." enum values. + */ +enum fsmonitor_path_type { + IS_WORKDIR_PATH = 0, + + IS_DOT_GIT, + IS_INSIDE_DOT_GIT, + IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX, + + IS_GITDIR, + IS_INSIDE_GITDIR, + IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX, + + IS_OUTSIDE_CONE, +}; + +/* + * Classify a pathname relative to the root of the working directory. + */ +enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative( + const char *relative_path); + +/* + * Classify a pathname relative to a that is external to the + * worktree directory. + */ +enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative( + const char *relative_path); + +/* + * Classify an absolute pathname received from a filesystem event. + */ +enum fsmonitor_path_type fsmonitor_classify_path_absolute( + struct fsmonitor_daemon_state *state, + const char *path); + #endif /* HAVE_FSMONITOR_DAEMON_BACKEND */ #endif /* FSMONITOR_DAEMON_H */