diff options
Diffstat (limited to 'sys/contrib/openzfs/lib/libspl/os/linux/mnttab.c')
| -rw-r--r-- | sys/contrib/openzfs/lib/libspl/os/linux/mnttab.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/lib/libspl/os/linux/mnttab.c b/sys/contrib/openzfs/lib/libspl/os/linux/mnttab.c new file mode 100644 index 000000000000..25fa132ac6fc --- /dev/null +++ b/sys/contrib/openzfs/lib/libspl/os/linux/mnttab.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: CDDL-1.0 +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License, Version 1.0 only + * (the "License"). You may not use this file except in compliance + * with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or https://opensource.org/licenses/CDDL-1.0. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2005 Sun Microsystems, Inc. All rights reserved. + * Copyright 2006 Ricardo Correia. All rights reserved. + * Use is subject to license terms. + */ + +/* Copyright (c) 1988 AT&T */ +/* All Rights Reserved */ + +#include <stdio.h> +#include <string.h> +#include <mntent.h> +#include <sys/errno.h> +#include <sys/mnttab.h> + +#include <sys/types.h> +#include <sys/sysmacros.h> +#include <sys/stat.h> +#include <unistd.h> +#include <libzutil.h> + +#define BUFSIZE (MNT_LINE_MAX + 2) + +static __thread char buf[BUFSIZE]; + +int +_sol_getmntent(FILE *fp, struct mnttab *mgetp) +{ + struct mntent mntbuf; + struct mntent *ret; + + ret = getmntent_r(fp, &mntbuf, buf, BUFSIZE); + + if (ret != NULL) { + mgetp->mnt_special = mntbuf.mnt_fsname; + mgetp->mnt_mountp = mntbuf.mnt_dir; + mgetp->mnt_fstype = mntbuf.mnt_type; + mgetp->mnt_mntopts = mntbuf.mnt_opts; + return (0); + } + + if (feof(fp)) + return (-1); + + return (MNT_TOOLONG); +} + +static int +getextmntent_impl(FILE *fp, struct mnttab *mp, uint64_t *mnt_id, dev_t *dev) +{ + int ret; + struct stat64 st; + + *mnt_id = 0; + ret = _sol_getmntent(fp, (struct mnttab *)mp); + if (ret == 0) { +#ifdef HAVE_STATX_MNT_ID + struct statx stx; + if (statx(AT_FDCWD, mp->mnt_mountp, + AT_STATX_SYNC_AS_STAT | AT_SYMLINK_NOFOLLOW, + STATX_MNT_ID, &stx) == 0 && (stx.stx_mask & STATX_MNT_ID)) + *mnt_id = stx.stx_mnt_id; +#endif + if (stat64(mp->mnt_mountp, &st) != 0) { + *dev = 0; + return (ret); + } + *dev = st.st_dev; + } + + return (ret); +} + +int +getextmntent(const char *path, struct mnttab *entry, struct stat64 *statbuf) +{ + struct stat64 st; + FILE *fp; + int match; + boolean_t have_mnt_id = B_FALSE; + uint64_t target_mnt_id = 0; + uint64_t entry_mnt_id; + dev_t dev; +#ifdef HAVE_STATX_MNT_ID + struct statx stx; +#endif + + if (strlen(path) >= MAXPATHLEN) { + (void) fprintf(stderr, "invalid object; pathname too long\n"); + return (-1); + } + + /* + * Search for the path in /proc/self/mounts. Rather than looking for the + * specific path, which can be fooled by non-standard paths (i.e. ".." + * or "//"), we stat() the path and search for the corresponding + * (major,minor) device pair. + */ + if (stat64(path, statbuf) != 0) { + (void) fprintf(stderr, "cannot open '%s': %s\n", + path, zfs_strerror(errno)); + return (-1); + } + +#ifdef HAVE_STATX_MNT_ID + if (statx(AT_FDCWD, path, AT_STATX_SYNC_AS_STAT | AT_SYMLINK_NOFOLLOW, + STATX_MNT_ID, &stx) == 0 && (stx.stx_mask & STATX_MNT_ID)) { + have_mnt_id = B_TRUE; + target_mnt_id = stx.stx_mnt_id; + } +#endif + + if ((fp = fopen(MNTTAB, "re")) == NULL) { + (void) fprintf(stderr, "cannot open %s\n", MNTTAB); + return (-1); + } + + /* + * Search for the given (major,minor) pair in the mount table. + */ + + match = 0; + while (getextmntent_impl(fp, entry, &entry_mnt_id, &dev) == 0) { + if (have_mnt_id) { + match = (entry_mnt_id == target_mnt_id); + } else { + match = (dev == statbuf->st_dev); + } + if (match) + break; + } + (void) fclose(fp); + + if (!match) { + (void) fprintf(stderr, "cannot find mountpoint for '%s'\n", + path); + return (-1); + } + + if (stat64(entry->mnt_mountp, &st) != 0) + return (-1); + + return (0); +} |