From patchwork Wed Nov 23 19:00:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric DeCosta X-Patchwork-Id: 13054133 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 1A523C3A59F for ; Wed, 23 Nov 2022 19:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239378AbiKWTAy (ORCPT ); Wed, 23 Nov 2022 14:00:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239159AbiKWTAw (ORCPT ); Wed, 23 Nov 2022 14:00:52 -0500 Received: from mail-wm1-x32f.google.com (mail-wm1-x32f.google.com [IPv6:2a00:1450:4864:20::32f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C05491C3E for ; Wed, 23 Nov 2022 11:00:51 -0800 (PST) Received: by mail-wm1-x32f.google.com with SMTP id 83-20020a1c0256000000b003d03017c6efso1517615wmc.4 for ; Wed, 23 Nov 2022 11:00:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:mime-version:content-transfer-encoding:fcc:subject:date:from :references:in-reply-to:message-id:from:to:cc:subject:date :message-id:reply-to; bh=WlX8fRoMkPnEolpDAbYR1NXBm53dpHMaf0+jydPyO8c=; b=emaLUmtqkoChOqRcbodtoAaY37x1SZSrHq0eDIrvFAbhIUkWIsSA+UHguqiczIaud0 NMr6llJuLPz6K2sBlmjKB420rUyD7uPOxALLp8bwO610TdzKSJeNevInbSOL9IG5mntR Tr5OB+tkpFHIXpPwJX8N+wg0owv/yMZQvS4Eul/surWEEsg7WB0UHVxPz5/2OrCmU6tD wsSiXuz+/CjQc+HAq8r4bdzTA25l8p/Fpk092MDszwQBbwY8mC9itMYsist/3JdZ5rs+ DhvUpR3Jxz0+2nHBq1+brCRwXy6vUM6lhMAa411/mtA1c7aquv6V7Fh5TzGHvZkOfMOv TIFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:mime-version:content-transfer-encoding:fcc:subject:date:from :references:in-reply-to:message-id:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WlX8fRoMkPnEolpDAbYR1NXBm53dpHMaf0+jydPyO8c=; b=exGq/ThC0DDHUwr/Kv/5zrfLxVeJdkKoJy3OJSauhQXZUUnM+IZQFLI6PLGvMYxR8e hJGfPuTOsAX+7NGps183adCiBfUW6NQ7n0DzvKP8Wl4ofnWqfMoiXWOMeBIYntSjoIAh oxm2hNezKzZbP2BWcxP6vSfyuiR6VxL7bzcQ/mk6VwRTgrKTczZpKEuwetC581tnUmHq RMThcLyh4CCy8SXLM24ZNao4kbvNMta2Ij1K3xTjlBybaBHd0yfOp/yGokKJ4QUiq04z sYR5rpZbjjApYQmdQKK4Vpw6U8RRZN2wIziGRb7NBIes49y1TUxMZ6BTDA84bERFqngo Unpw== X-Gm-Message-State: ANoB5pkA3/CBYR0rfmoB3mWCBo8WCZ8GGZHGIv6wsPPSi7+IT9vg7tvq 6yFGSI+gv8ug89a+5nxMCWw3EiZwmbo= X-Google-Smtp-Source: AA0mqf5UjVrv8BM2Xtkdq37PCaLiZrB6WvMxpiyfGpM9/LyTpqmBMdE/cvOe2OMmOV02bTFVsXxsgQ== X-Received: by 2002:a05:600c:3c96:b0:3cf:a457:2d89 with SMTP id bg22-20020a05600c3c9600b003cfa4572d89mr24138186wmb.20.1669230049495; Wed, 23 Nov 2022 11:00:49 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id iw8-20020a05600c54c800b003cfbe1da539sm3115993wmb.36.2022.11.23.11.00.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 11:00:48 -0800 (PST) Message-Id: In-Reply-To: References: Date: Wed, 23 Nov 2022 19:00:40 +0000 Subject: [PATCH v4 2/6] fsmonitor: determine if filesystem is local or remote Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Eric Sunshine , =?utf-8?b?w4Z2YXIgQXJuZmrDtnI=?= =?utf-8?b?w7A=?= Bjarmason , Glen Choo , Johannes Schindelin , Taylor Blau , Eric DeCosta , Eric DeCosta Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Eric DeCosta From: Eric DeCosta Compare the given path to the mounted filesystems. Find the mount that is the longest prefix of the path (if any) and determine if that mount is on a local or remote filesystem. Signed-off-by: Eric DeCosta --- compat/fsmonitor/fsm-path-utils-linux.c | 186 ++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 compat/fsmonitor/fsm-path-utils-linux.c diff --git a/compat/fsmonitor/fsm-path-utils-linux.c b/compat/fsmonitor/fsm-path-utils-linux.c new file mode 100644 index 00000000000..d3281422ebc --- /dev/null +++ b/compat/fsmonitor/fsm-path-utils-linux.c @@ -0,0 +1,186 @@ +#include "fsmonitor.h" +#include "fsmonitor-path-utils.h" +#include +#include +#include +#include +#include + +static int is_remote_fs(const char* path) { + struct statfs fs; + + if (statfs(path, &fs)) { + error_errno(_("statfs('%s') failed"), path); + return -1; + } + + switch (fs.f_type) { + case 0x61636673: /* ACFS */ + case 0x5346414F: /* AFS */ + case 0x00C36400: /* CEPH */ + case 0xFF534D42: /* CIFS */ + case 0x73757245: /* CODA */ + case 0x19830326: /* FHGFS */ + case 0x1161970: /* GFS */ + case 0x47504653: /* GPFS */ + case 0x013111A8: /* IBRIX */ + case 0x6B414653: /* KAFS */ + case 0x0BD00BD0: /* LUSTRE */ + case 0x564C: /* NCP */ + case 0x6969: /* NFS */ + case 0x6E667364: /* NFSD */ + case 0x7461636f: /* OCFS2 */ + case 0xAAD7AAEA: /* PANFS */ + case 0x517B: /* SMB */ + case 0xBEEFDEAD: /* SNFS */ + case 0xFE534D42: /* SMB2 */ + case 0xBACBACBC: /* VMHGFS */ + case 0xA501FCF5: /* VXFS */ + return 1; + default: + break; + } + + return 0; +} + +static int find_mount(const char *path, const struct statvfs *fs, + struct mntent *ent) +{ + const char *const mounts = "/proc/mounts"; + const char *rp = real_pathdup(path, 1); + struct mntent *ment = NULL; + struct statvfs mntfs; + FILE *fp; + int found = 0; + int dlen, plen, flen = 0; + + ent->mnt_fsname = NULL; + ent->mnt_dir = NULL; + ent->mnt_type = NULL; + + fp = setmntent(mounts, "r"); + if (!fp) { + error_errno(_("setmntent('%s') failed"), mounts); + return -1; + } + + plen = strlen(rp); + + /* read all the mount information and compare to path */ + while ((ment = getmntent(fp)) != NULL) { + if (statvfs(ment->mnt_dir, &mntfs)) { + switch (errno) { + case EPERM: + case ESRCH: + case EACCES: + continue; + default: + error_errno(_("statvfs('%s') failed"), ment->mnt_dir); + endmntent(fp); + return -1; + } + } + + /* is mount on the same filesystem and is a prefix of the path */ + if ((fs->f_fsid == mntfs.f_fsid) && + !strncmp(ment->mnt_dir, rp, strlen(ment->mnt_dir))) { + dlen = strlen(ment->mnt_dir); + if (dlen > plen) + continue; + /* + * root is always a potential match; otherwise look for + * directory prefix + */ + if ((dlen == 1 && ment->mnt_dir[0] == '/') || + (dlen > flen && (!rp[dlen] || rp[dlen] == '/'))) { + flen = dlen; + /* + * https://man7.org/linux/man-pages/man3/getmntent.3.html + * + * The pointer points to a static area of memory which is + * overwritten by subsequent calls to getmntent(). + */ + found = 1; + free(ent->mnt_fsname); + free(ent->mnt_dir); + free(ent->mnt_type); + ent->mnt_fsname = xstrdup(ment->mnt_fsname); + ent->mnt_dir = xstrdup(ment->mnt_dir); + ent->mnt_type = xstrdup(ment->mnt_type); + } + } + } + endmntent(fp); + + if (!found) + return -1; + + return 0; +} + +int fsmonitor__get_fs_info(const char *path, struct fs_info *fs_info) +{ + struct mntent ment; + struct statvfs fs; + + if (statvfs(path, &fs)) + return error_errno(_("statvfs('%s') failed"), path); + + + if (find_mount(path, &fs, &ment) < 0) { + free(ment.mnt_fsname); + free(ment.mnt_dir); + free(ment.mnt_type); + return -1; + } + + trace_printf_key(&trace_fsmonitor, + "statvfs('%s') [flags 0x%08lx] '%s' '%s'", + path, fs.f_flag, ment.mnt_type, ment.mnt_fsname); + + fs_info->is_remote = is_remote_fs(ment.mnt_dir); + fs_info->typename = ment.mnt_fsname; + free(ment.mnt_dir); + free(ment.mnt_type); + + if (fs_info->is_remote < 0) { + free(ment.mnt_fsname); + return -1; + } + + trace_printf_key(&trace_fsmonitor, + "'%s' is_remote: %d", + path, fs_info->is_remote); + + return 0; +} + +int fsmonitor__is_fs_remote(const char *path) +{ + struct fs_info fs; + + if (fsmonitor__get_fs_info(path, &fs)) + return -1; + + free(fs.typename); + + return fs.is_remote; +} + +/* + * No-op for now. + */ +int fsmonitor__get_alias(const char *path, struct alias_info *info) +{ + return 0; +} + +/* + * No-op for now. + */ +char *fsmonitor__resolve_alias(const char *path, + const struct alias_info *info) +{ + return NULL; +}