From f2ada8ea7939bc8f607d88a10c92d5bb96a700b8 Mon Sep 17 00:00:00 2001 From: Werner Fink Date: Fri, 7 May 2021 16:36:28 +0200 Subject: [PATCH] Use new statx(2) system call to avoid hangs on NFS Signed-off-by: Werner Fink --- Makefile.am | 4 +- configure.ac | 38 ++---- src/fuser.c | 102 ++++---------- src/statx.c | 149 ++++++++++++++++++++ src/statx.h | 68 ++++++++++ src/timeout.c | 369 -------------------------------------------------- src/timeout.h | 45 ------ 7 files changed, 260 insertions(+), 515 deletions(-) create mode 100644 src/statx.c create mode 100644 src/statx.h delete mode 100644 src/timeout.c delete mode 100644 src/timeout.h diff --git Makefile.am Makefile.am index 8067689..ea44203 100644 --- Makefile.am +++ Makefile.am @@ -65,8 +65,8 @@ src_fuser_SOURCES = \ src/fuser.h \ src/lists.h -if WANT_TIMEOUT_STAT -src_fuser_SOURCES += src/timeout.c src/timeout.h +if HAVE_SYSCALL_STATX +src_fuser_SOURCES += src/statx.c src/statx.h endif src_fuser_LDADD = @LIBINTL@ src_killall_SOURCES = src/killall.c src/comm.h src/signals.c src/signals.h src/i18n.h diff --git configure.ac configure.ac index d4dee51..eda0e62 100644 --- configure.ac +++ configure.ac @@ -46,20 +46,6 @@ if test "$enable_selinux" = "yes"; then fi AC_SUBST([DL_LIB]) -# Call fork before all stat calls to stop hanging on NFS mounts -AC_SUBST([WITH_TIMEOUT_STAT]) -AC_ARG_ENABLE([timeout_stat], - [AS_HELP_STRING([--enable-timeout-stat], [Use a timeout on stat calls (optional with argument "static" for a static background process)])], - [enable_timeout_stat=$enableval], - [enable_timeout_stat="no"]) -if test "$enable_timeout_stat" = "yes"; then - AC_DEFINE([WITH_TIMEOUT_STAT], [1], [Use timeout on stat calls]) -fi -if test "$enable_timeout_stat" = "static"; then - AC_DEFINE([WITH_TIMEOUT_STAT], [2], [Use timeout on stat calls]) -fi -AM_CONDITIONAL([WANT_TIMEOUT_STAT], [test "$enable_timeout_stat" = "static"]) - # Use /proc/self/mountinfo if available if test -e /proc/self/mountinfo ; then AC_DEFINE([HAS_MOUNTINFO], [1], [System has /proc/self/mountinfo which can used instead /proc(/self)/mounts]) @@ -73,16 +59,20 @@ fi AC_CHECK_FUNC([name_to_handle_at],[ AC_DEFINE([HAS_NAME_TO_HANDLE_AT], [1], [System has name_to_handle_at(2) system call])]) -# Use string search for network based file systems but only if the system -# has /proc/self/mountinfo -AC_SUBST([WITH_MOUNTINFO_LIST]) -AC_ARG_ENABLE([mountinfo_list], - [AS_HELP_STRING([--enable-mountinfo-list], [Use the list in /proc/self/mountinfo to replace stat(2) syscall on network file systems shares])], - [enable_mountinfo_list="yes"], - [enable_mountinfo_list="no"]) -if test "$enable_mountinfo_list" = "yes" -a -e /proc/self/mountinfo ; then - AC_DEFINE([WITH_MOUNTINFO_LIST], [1], [Use list in /proc/self/mountinfo to replace stat calls]) -fi +AC_CHECK_HEADERS([sys/syscall.h]) +AC_CHECK_DECLS([SYS_statx], + [has_syscall_statx="yes"], + [has_syscall_statx="no"], + [[#include ]] +) +AC_CHECK_FUNCS([statx]) +# Check for linux specific statx(2) system call +AC_SUBST([HAS_SYSCALL_STATX]) +AC_ARG_ENABLE([disable_statx], + [AS_HELP_STRING([--disable-statx], [Do not use linux specific statx(2) system call as replacement for stat(2), lstat(2), and fstat(2)])], + [enable_syscall_statx="no"], + [enable_syscall_statx=$has_syscall_statx]) +AM_CONDITIONAL([HAVE_SYSCALL_STATX], [test "$enable_syscall_statx" = "yes"]) # Enable hardened compile and link flags AC_ARG_ENABLE([harden_flags], diff --git src/fuser.c src/fuser.c index dd928d2..d08f7a9 100644 --- src/fuser.c +++ src/fuser.c @@ -65,7 +65,7 @@ #include "fuser.h" #include "signals.h" #include "i18n.h" -#include "timeout.h" +#include "statx.h" #include "comm.h" //#define DEBUG 1 @@ -127,10 +127,6 @@ static int get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info); static int get_mountid(const char *path); #endif static int find_mountpoint(const char *path, mntinfo_t **mountinfo); -#if defined(WITH_MOUNTINFO_LIST) -static int mntstat(const char *path, struct stat *buf); -#endif -static stat_t thestat = stat; static char *expandpath(const char *path); static struct unixsocket_list *unixsockets = NULL; static struct names *names_head = NULL, *names_tail = NULL; @@ -518,7 +514,7 @@ int parse_file(struct names *this_name, struct inode_list **ino_list, free(this_name->filename); this_name->filename = strdup(new); } - if (timeout(thestat, this_name->filename, &(this_name->st), 5) != 0 || + if (statn(this_name->filename, STATX_INO|STATX_TYPE, &(this_name->st)) != 0 || find_mountpoint(this_name->filename, &mountinfo) != 0) { if (errno == ENOENT) fprintf(stderr, @@ -1252,9 +1248,7 @@ int main(int argc, char *argv[]) opts |= OPT_INTERACTIVE; break; case 'I': -#if defined(WITH_MOUNTINFO_LIST) opts |= OPT_ALWAYSSTAT; -#endif break; case 'k': opts |= OPT_KILL; @@ -1320,10 +1314,11 @@ int main(int argc, char *argv[]) continue; } -#if defined(WITH_MOUNTINFO_LIST) - if ((opts & (OPT_MOUNTS|OPT_ALWAYSSTAT)) == OPT_MOUNTS) - thestat = mntstat; +#if defined(HAVE_DECL_SYS_STATX) && HAVE_DECL_SYS_STATX == 1 + if ((opts & OPT_ALWAYSSTAT)) + stat_flags = 0; /* Triggers sync with e.g. remote NFS server even on autofs */ #endif + /* an option */ /* Not an option, must be a file specification */ if ((this_name = malloc(sizeof(struct names))) == NULL) @@ -1643,7 +1638,7 @@ static struct stat *get_pidstat(const pid_t pid, const char *filename, int *id) if ((st = (struct stat *)malloc(sizeof(struct stat))) == NULL) return NULL; snprintf(pathname, PATH_MAX-1, "/proc/%d/%s", pid, filename); - if (timeout(thestat, pathname, st, 5) != 0) { + if (statn(pathname, STATX_UID|STATX_INO|STATX_TYPE, st) != 0) { free(st); return NULL; } @@ -1690,7 +1685,7 @@ check_dir(const pid_t pid, const char *dirname, struct device_list *dev_head, snprintf(filepath, sizeof filepath - 1, "/proc/%d/%s/%s", pid, dirname, direntry->d_name); - if (timeout(thestat, filepath, &st, 5) != 0) { + if (statn(filepath, STATX_INO, &st) != 0) { if (errno != ENOENT && errno != ENOTDIR) { fprintf(stderr, _("Cannot stat file %s: %s\n"), filepath, strerror(errno)); @@ -1767,7 +1762,7 @@ check_dir(const pid_t pid, const char *dirname, struct device_list *dev_head, if (thedev != ino_tmp->device) continue; if (!st.st_ino - && timeout(thestat, filepath, &st, 5) != 0) { + && statn(filepath, STATX_INO, &st) != 0) { fprintf(stderr, _("Cannot stat file %s: %s\n"), filepath, strerror(errno)); @@ -1865,11 +1860,11 @@ static uid_t getpiduid(const pid_t pid) if (asprintf(&pathname, "/proc/%d", pid) < 0) return 0; - if (timeout(thestat, pathname, &st, 5) != 0) { - free(pathname); + if (statn(pathname, STATX_UID, &st) != 0) { + free(pathname); return 0; - } - free(pathname); + } + free(pathname); return st.st_uid; } @@ -1907,7 +1902,7 @@ void fill_unix_cache(struct unixsocket_list **unixsocket_head) path = scanned_path; if (*scanned_path == '@') scanned_path++; - if (timeout(thestat, scanned_path, &st, 5) < 0) { + if (statn(scanned_path, STATX_INO, &st) < 0) { free(path); continue; } @@ -2042,7 +2037,7 @@ static dev_t find_net_dev(void) fprintf(stderr, _("Cannot open a network socket.\n")); return -1; } - if (fstat(skt, &st) != 0) { + if (fstatn(skt, STATX_INO, &st) != 0) { fprintf(stderr, _("Cannot find socket's device number.\n")); close(skt); return -1; @@ -2079,7 +2074,7 @@ scan_knfsd(struct names *names_head, struct inode_list *ino_head, if ((find_space = strpbrk(line, " \t")) == NULL) continue; *find_space = '\0'; - if (timeout(thestat, line, &st, 5) != 0) { + if (statn(line, STATX_INO, &st) != 0) { continue; } /* Scan the devices */ @@ -2113,7 +2108,7 @@ scan_mounts(struct names *names_head, struct inode_list *ino_head, mntinfo_t *mnt = list_entry(ptr, mntinfo_t); const char *find_mountp = mnt->mpoint; - if (timeout(thestat, find_mountp, &st, 5) != 0) + if (statn(find_mountp, STATX_INO, &st) != 0) continue; /* Scan the devices */ @@ -2163,7 +2158,7 @@ scan_swaps(struct names *names_head, struct inode_list *ino_head, if (*find_space == '\0') continue; } - if (timeout(thestat, line, &st, 5) != 0) { + if (statn(line, STATX_INO, &st) != 0) { continue; } /* Scan the devices */ @@ -2260,10 +2255,10 @@ init_mntinfo(void) &mid, &parid, &maj, &min, &mpoint[0], &type[0], &devname[0]) == 7) { struct stat st; mntinf = add_mntinfo(mpoint, type, mid, parid, makedev(maj, min)); - if (mntinf && strncmp(devname, "/dev/", 5) == 0 && stat(devname, &st) == 0) { + if (mntinf && strncmp(devname, "/dev/", 5) == 0 && statn(devname, 0, &st) == 0) { if (st.st_rdev != 0 && mntinf->dev != st.st_rdev) { mntinf->vol = st.st_rdev; - stat(mpoint, &st); + statn(mpoint, 0, &st); mntinf->dev = st.st_dev; /* stat(2) on binary does not see subvol dev */ } } @@ -2275,7 +2270,7 @@ init_mntinfo(void) parid = -1; while (fscanf (mnt, "%s %s %s %*[^\n]", &devname[0], &mpoint[0], &type[0]) == 3) { struct stat st; - if (stat(mpoint, &st) != 0) { + if (statn(mpoint, 0, &st) != 0) { if (errno != EACCES) { fprintf(stderr, _("Cannot stat %s: %s\n"), mpoint, strerror(errno)); @@ -2284,7 +2279,7 @@ init_mntinfo(void) st.st_dev = (dev_t)-1; } mntinf = add_mntinfo(mpoint, type, mid++, parid, st.st_dev); - if (mntinf && strncmp(devname, "/dev/", 5) == 0 && stat(devname, &st) == 0) { + if (mntinf && strncmp(devname, "/dev/", 5) == 0 && statn(devname, 0, &st) == 0) { if (st.st_rdev != 0 && mntinf->dev != st.st_rdev) mntinf->vol = st.st_rdev; } @@ -2308,7 +2303,7 @@ get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info) struct stat st; if (!mynamespace) { - if (stat("/proc/self/ns/mnt", &st) != 0) { + if (statn("/proc/self/ns/mnt", STATX_INO, &st) != 0) { fprintf(stderr, _("Cannot stat %s: %s\n"), "/proc/self/ns/mnt", strerror(errno)); exit(1); @@ -2343,7 +2338,7 @@ get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info) out: # if defined(HAS_NAME_TO_HANDLE_AT) snprintf(pathname, 256, "/proc/%d/ns/mnt", pid); - if (stat(pathname, &st) == 0 && mynamespace != st.st_ino) { + if (statn(pathname, STATX_INO, &st) == 0 && mynamespace != st.st_ino) { char *realname; snprintf(pathname, 256, "/proc/%d/fd/%s", pid, fd); realname = expandpath(pathname); @@ -2358,7 +2353,7 @@ out: struct stat lst; snprintf(pathname, 256, "/proc/%d/fd/%s", pid, fd); - if (!flags && lstat(pathname, &lst) == 0) { + if (!flags && lstatn(pathname, STATX_MODE, &lst) == 0) { if (lst.st_mode & S_IWUSR) info->flags |= O_WRONLY; ret++; @@ -2431,7 +2426,7 @@ find_mountpoint(const char *path, mntinfo_t **mountinfo) /* could be a chroot or a container */ - if (stat(path, &st) != 0) { + if (statn(path, 0, &st) != 0) { if (errno != EACCES) { fprintf(stderr, _("Cannot stat %s: %s\n"), path, strerror(errno)); @@ -2463,7 +2458,7 @@ find_mountpoint(const char *path, mntinfo_t **mountinfo) /* could be a chroot or a container */ - if (stat(use, &st) != 0) { + if (statn(use, 0, &st) != 0) { if (errno != EACCES) { fprintf(stderr, _("Cannot stat %s: %s\n"), use, strerror(errno)); @@ -2501,49 +2496,6 @@ out: return ret; } -#if defined(WITH_MOUNTINFO_LIST) -/* - * Determine device of links below /proc/ - */ -static int mntstat(const char *path, struct stat *buf) -{ - char name[PATH_MAX + 1]; - const char *use; - mntinfo_t *mnt; - - if ((use = realpath(path, name)) == NULL || *use != '/') - { - if (errno == ENOENT) - return -1; - /* - * Could be a special file (socket, pipe, inotify) - */ - errno = 0; - return stat(path, buf); - } - if (strncmp("/dev/", use, 5) == 0) { - /* - * Could be a special file (socket, pipe, inotify) - */ - errno = 0; - return stat(path, buf); - } - - if (find_mountpoint(use, &mnt) < 0) { - errno = ENOENT; - return -1; - } - - if (mnt->isremote) { - buf->st_dev = mnt->dev; - buf->st_ino = mnt->id; /* inode substitute */ - return 0; /* found on NFS */ - } - - return stat(path, buf); -} -#endif /* WITH_MOUNTINFO_LIST */ - /* * Somehow the realpath(3) glibc function call, nevertheless * it avoids lstat(2) system calls. diff --git src/statx.c src/statx.c new file mode 100644 index 0000000..a598c89 --- /dev/null +++ src/statx.c @@ -0,0 +1,149 @@ +/* + * statx.c - Map modern statx(2) system call to older stat(2), lstat(2), + * and fstat(2) replacements named {,l,f}statn() + * + * Copyright (C) 2018 Werner Fink + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#ifdef HAVE_CONFIG_H +#include +#endif + +#ifndef HAVE_STATX +# define _ASM_GENERIC_FCNTL_H /* Avoid collisions between asm/fcntl.h and bits/fcntl.h ! */ +# include /* Definition of AT_* and AT_STATX_* constants ! */ +#endif +#include /* Definition of AT_* constants */ +#include +#ifndef HAVE_STATX +# ifndef STATX_TYPE +# include /* Provides 'struct statx' and STATX_* ! */ +# endif +#endif +#include +#include +#include +#include + +int stat_flags = AT_NO_AUTOMOUNT|AT_STATX_DONT_SYNC; + +int statn(const char *pathname, unsigned int mask, struct stat *st) +{ + int flags = stat_flags; + int dirfd = pathname && *pathname == '/' ? 0 : AT_FDCWD; + int ret; + struct statx stx; + +#ifndef HAVE_STATX + ret = syscall(SYS_statx, dirfd, pathname, flags, mask, &stx); +#else + ret = statx(dirfd, pathname, flags, mask, &stx); +#endif + if (ret >= 0) { + st->st_dev = makedev(stx.stx_dev_major, stx.stx_dev_minor); + st->st_rdev = makedev(stx.stx_rdev_major, stx.stx_rdev_minor); + + st->st_ino = stx.stx_ino; + st->st_mode = stx.stx_mode; + st->st_nlink = stx.stx_nlink; + st->st_uid = stx.stx_uid; + st->st_gid = stx.stx_gid; + st->st_size = stx.stx_size; + st->st_blksize = stx.stx_blksize; + st->st_blocks = stx.stx_blocks; + + st->st_atim.tv_sec = stx.stx_atime.tv_sec; + st->st_atim.tv_nsec = stx.stx_atime.tv_nsec; + st->st_mtim.tv_sec = stx.stx_mtime.tv_sec; + st->st_mtim.tv_nsec = stx.stx_mtime.tv_nsec; + st->st_ctim.tv_sec = stx.stx_ctime.tv_sec; + st->st_ctim.tv_nsec = stx.stx_ctime.tv_nsec; + } + return ret; +} + +int fstatn(int fd, unsigned int mask, struct stat *st) +{ + int flags = AT_EMPTY_PATH|stat_flags; + int ret; + struct statx stx; + +#ifndef HAVE_STATX + ret = syscall(SYS_statx, fd, "", flags, mask, &stx); +#else + ret = statx(fd, "", flags, mask, &stx); +#endif + if (ret >= 0) { + st->st_dev = makedev(stx.stx_dev_major, stx.stx_dev_minor); + st->st_rdev = makedev(stx.stx_rdev_major, stx.stx_rdev_minor); + + st->st_ino = stx.stx_ino; + st->st_mode = stx.stx_mode; + st->st_nlink = stx.stx_nlink; + st->st_uid = stx.stx_uid; + st->st_gid = stx.stx_gid; + st->st_size = stx.stx_size; + st->st_blksize = stx.stx_blksize; + st->st_blocks = stx.stx_blocks; + + st->st_atim.tv_sec = stx.stx_atime.tv_sec; + st->st_atim.tv_nsec = stx.stx_atime.tv_nsec; + st->st_mtim.tv_sec = stx.stx_mtime.tv_sec; + st->st_mtim.tv_nsec = stx.stx_mtime.tv_nsec; + st->st_ctim.tv_sec = stx.stx_ctime.tv_sec; + st->st_ctim.tv_nsec = stx.stx_ctime.tv_nsec; + } + return ret; +} + +int lstatn(const char *pathname, unsigned int mask, struct stat *st) +{ + int flags = AT_SYMLINK_NOFOLLOW|stat_flags; + int dirfd = pathname && *pathname == '/' ? 0 : AT_FDCWD; + int ret; + struct statx stx; + +#ifndef HAVE_STATX + ret = syscall(SYS_statx, dirfd, pathname, flags, mask, &stx); +#else + ret = statx(dirfd, pathname, flags, mask, &stx); +#endif + if (ret >= 0) { + st->st_dev = makedev(stx.stx_dev_major, stx.stx_dev_minor); + st->st_rdev = makedev(stx.stx_rdev_major, stx.stx_rdev_minor); + + st->st_ino = stx.stx_ino; + st->st_mode = stx.stx_mode; + st->st_nlink = stx.stx_nlink; + st->st_uid = stx.stx_uid; + st->st_gid = stx.stx_gid; + st->st_size = stx.stx_size; + st->st_blksize = stx.stx_blksize; + st->st_blocks = stx.stx_blocks; + + st->st_atim.tv_sec = stx.stx_atime.tv_sec; + st->st_atim.tv_nsec = stx.stx_atime.tv_nsec; + st->st_mtim.tv_sec = stx.stx_mtime.tv_sec; + st->st_mtim.tv_nsec = stx.stx_mtime.tv_nsec; + st->st_ctim.tv_sec = stx.stx_ctime.tv_sec; + st->st_ctim.tv_nsec = stx.stx_ctime.tv_nsec; + } + return ret; +} diff --git src/statx.h src/statx.h new file mode 100644 index 0000000..fdd0137 --- /dev/null +++ src/statx.h @@ -0,0 +1,68 @@ +/* + * statx.h - Map modern statx(2) system call to older stat(2), lstat(2), + * and fstat(2) replacements named {,l,f}statn() + * + * Copyright (C) 2018 Werner Fink + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef _STATX_H +#define _STATX_H + +extern int stat_flags; +#if defined(HAVE_DECL_SYS_STATX) && HAVE_DECL_SYS_STATX == 1 +# ifndef HAVE_STATX +# define _ASM_GENERIC_FCNTL_H /* Avoid collisions between asm/fcntl.h and bits/fcntl.h ! */ +# include /* Definition of AT_* and AT_STATX_* constants ! */ +# ifndef STATX_TYPE +# include /* Provides 'struct statx' and STATX_* ! */ +# endif +# endif +extern int statn(const char*, unsigned int, struct stat*); +extern int fstatn(int, unsigned int, struct stat*); +extern int lstatn(const char*, unsigned int, struct stat*); +#else +extern inline int +statn(const char *path, unsigned int mask __attribute__((unused)), struct stat *st) +{ + return stat(path, st); +} +extern inline int +fstatn(int fd, unsigned int mask __attribute__((unused)), struct stat *st) +{ + return fstat(fd, st); +} +extern inline int +lstatn(const char *path, unsigned int mask __attribute__((unused)), struct stat *st) +{ + return lstat(path, st); +} +#define STATX_TYPE 0 +#define STATX_MODE 0 +#define STATX_NLINK 0 +#define STATX_UID 0 +#define STATX_GID 0 +#define STATX_ATIME 0 +#define STATX_MTIME 0 +#define STATX_CTIME 0 +#define STATX_INO 0 +#define STATX_SIZE 0 +#define STATX_BLOCKS 0 +#define STATX_BASIC_STATS 0 +#define STATX_BTIME 0 +#define STATX_ALL 0 +#endif +#endif diff --git src/timeout.c src/timeout.c deleted file mode 100644 index a3c7055..0000000 --- src/timeout.c +++ /dev/null @@ -1,369 +0,0 @@ -/* - * timout.c Advanced timeout handling for file system calls - * to avoid deadlocks on remote file shares. - * - * Version: 0.2 11-Dec-2012 Fink - * - * Copyright 2011,2012 Werner Fink, 2011,2012 SUSE LINUX Products GmbH, Germany. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * Author: Werner Fink , 2011 - */ - -#ifndef _GNU_SOURCE -# define _GNU_SOURCE -#endif - -#ifdef _FEATURES_H -# error Include local config.h before any system header file -#endif -#include "config.h" - -#ifndef WITH_TIMEOUT_STAT -# define WITH_TIMEOUT_STAT 0 -#endif - -#ifndef USE_SOCKETPAIR -# define USE_SOCKETPAIR 1 -#endif - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#if USE_SOCKETPAIR -# include -# include -# include -# ifndef SHUT_RD -# define SHUT_RD 0 -# endif -# ifndef SHUT_WR -# define SHUT_WR 1 -# endif -# undef pipe -# define pipe(v) (((socketpair(AF_UNIX,SOCK_STREAM,0,v) < 0) || \ - (shutdown((v)[1],SHUT_RD) < 0) || (shutdown((v)[0],SHUT_WR) < 0)) ? -1 : 0) -#endif -#include - -#include "timeout.h" - -#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) -# ifndef destructor -# define destructor __destructor__ -# endif -# ifndef constructor -# define constructor __constructor__ -# endif -# ifndef inline -# define inline __inline__ -# endif -# ifndef unused -# define unused __unused__ -# endif -# ifndef volatile -# define volatile __volatile__ -# endif -#endif -#ifndef attribute -# define attribute(attr) __attribute__(attr) -#endif - -#if defined __GNUC__ -# undef strcpy -# define strcpy(d,s) __builtin_strcpy((d),(s)) /* Without boundary check please */ -#endif - -#if WITH_TIMEOUT_STAT -static sigjmp_buf jenv; -static void sigjump(int sig attribute((unused))) -{ - siglongjmp(jenv, 1); -} -#endif - -#if WITH_TIMEOUT_STAT == 2 -/* - * The structure used for communication between the processes - */ -typedef struct _handle { - int errcode; - struct stat argument; - stat_t function; - size_t len; - char path[0]; -} handle_t; - -/* - * Using a forked process for doing e.g. stat(2) system call as this - * allows us to send e.g. SIGKILL to this process if it hangs in `D' - * state on a file share due a stalled NFS server. This does not work - * with (p)threads as SIGKILL would kill all threads including main. - */ - -static volatile pid_t active; -static int pipes[4] = {-1, -1, -1, -1}; -static handle_t *restrict handle; -static const size_t buflen = PATH_MAX+sizeof(handle_t)+1; - -static void sigchild(int sig attribute((unused))) -{ - pid_t pid = waitpid(active, NULL, WNOHANG|WUNTRACED); - if (pid <= 0) - return; - if (errno == ECHILD) - return; - active = 0; -} - -static void attribute((constructor)) start(void) -{ - sigset_t sigset, oldset; - struct sigaction act; - char sync[1]; - ssize_t in; - - if (pipes[1] >= 0) close(pipes[1]); - if (pipes[2] >= 0) close(pipes[2]); - - if (pipe(&pipes[0])) - goto error; - if (pipe(&pipes[2])) - goto error; - - memset(&act, 0, sizeof(act)); - sigemptyset(&act.sa_mask); - act.sa_flags = SA_RESTART; - act.sa_handler = sigchild; - sigaction(SIGCHLD, &act, 0); - - if (!handle) - handle = mmap(NULL, buflen, PROT_READ|PROT_WRITE, - MAP_ANONYMOUS|MAP_SHARED, -1, 0); - if (handle == MAP_FAILED) - goto error; - - if ((active = fork()) < 0) - goto error; - - if (active) { - close(pipes[0]); - close(pipes[3]); - pipes[0] = pipes[3] = -1; - return; - } - - sigemptyset(&sigset); - sigaddset(&sigset, SIGALRM); - sigprocmask(SIG_BLOCK, &sigset, &oldset); - - act.sa_handler = SIG_DFL; - sigaction(SIGCHLD, &act, 0); - - close(pipes[1]); - close(pipes[2]); - dup2(pipes[0], STDIN_FILENO); - dup2(pipes[3], STDOUT_FILENO); - close(pipes[0]); - close(pipes[3]); - pipes[1] = pipes[2] = -1; - pipes[0] = pipes[3] = -1; - - while ((in = read(STDIN_FILENO, &sync, sizeof(sync))) != 0) { - ssize_t out; - if (in < 0) { - if (errno == EINTR) - continue; - break; - } - if (!handle) - break; - if (handle->function(handle->path, &handle->argument) < 0) - handle->errcode = errno; - do - out = write(STDOUT_FILENO, &sync, sizeof(sync)); - while (out < 0 && errno == EINTR); - } - - sigprocmask(SIG_SETMASK, &oldset, NULL); - exit(0); -error: - if (pipes[0] >= 0) close(pipes[0]); - if (pipes[1] >= 0) close(pipes[1]); - if (pipes[2] >= 0) close(pipes[2]); - if (pipes[3] >= 0) close(pipes[3]); - if (handle && handle != MAP_FAILED) - munmap(handle, buflen); - handle = NULL; -} - -static void /* attribute((destructor)) */ stop(void) -{ - if (active && waitpid(active, NULL, WNOHANG|WUNTRACED) == 0) - kill(active, SIGKILL); -} - -/* - * External routine - * - * Execute stat(2) system call with timeout to avoid deadlock - * on network based file systems. - * - */ -int -timeout(stat_t function, const char *path, struct stat *restrict argument, time_t seconds) -{ - struct sigaction alrm_act, pipe_act, new_act; - sigset_t sigset, oldset; - char sync[1] = "x"; - - if (active <= 0) /* Oops, last one failed therefore clear status and restart */ - start(); - if (!handle) /* No shared memory area */ - return function(path, argument); - memset(handle, 0, sizeof(handle_t)); - handle->len = strlen(path) + 1; - if (handle->len >= PATH_MAX) { - errno = ENAMETOOLONG; - goto error; - } - handle->errcode = 0; - handle->argument = *argument; - handle->function = function; - strcpy(handle->path, path); - - sigemptyset(&sigset); - sigaddset(&sigset, SIGALRM); - sigaddset(&sigset, SIGPIPE); - sigprocmask(SIG_UNBLOCK, &sigset, &oldset); - - memset(&new_act, 0, sizeof(new_act)); - sigemptyset(&new_act.sa_mask); - new_act.sa_flags = SA_RESETHAND; - - if (sigsetjmp(jenv, 1)) - goto timed; - - new_act.sa_handler = sigjump; - sigaction(SIGALRM, &new_act, &alrm_act); - sigaction(SIGPIPE, &new_act, &pipe_act); - alarm(seconds); - - write(pipes[1], &sync, sizeof(sync)); - read(pipes[2], &sync, sizeof(sync)); - - alarm(0); - sigaction(SIGPIPE, &pipe_act, NULL); - sigaction(SIGALRM, &alrm_act, NULL); - - if (handle->errcode) { - errno = handle->errcode; - goto error; - } - - *argument = handle->argument; - sigprocmask(SIG_SETMASK, &oldset, NULL); - - return 0; -timed: - (void) alarm(0); - sigaction(SIGPIPE, &pipe_act, NULL); - sigaction(SIGALRM, &alrm_act, NULL); - sigprocmask(SIG_SETMASK, &oldset, NULL); - stop(); - errno = ETIMEDOUT; -error: - return -1; -} -#elif WITH_TIMEOUT_STAT == 1 -/* - * External routine - * - * Execute stat(2) system call with timeout to avoid deadlock - * on network based file systems. - * - */ -int -timeout(stat_t function, const char *path, struct stat *restrict argument, time_t seconds) -{ - struct sigaction alrm_act, pipe_act, new_act; - sigset_t sigset, oldset; - int ret = 0, pipes[4]; - pid_t pid = 0; - ssize_t len; - - if (pipe(&pipes[0]) < 0) - goto error; - switch ((pid = fork())) { - case -1: - close(pipes[0]); - close(pipes[1]); - goto error; - case 0: - new_act.sa_handler = SIG_DFL; - sigaction(SIGALRM, &new_act, NULL); - close(pipes[0]); - if ((ret = function(path, argument)) == 0) - do - len = write(pipes[1], argument, sizeof(struct stat)); - while (len < 0 && errno == EINTR); - close(pipes[1]); - exit(ret); - default: - close(pipes[1]); - - sigemptyset(&sigset); - sigaddset(&sigset, SIGALRM); - sigaddset(&sigset, SIGPIPE); - sigprocmask(SIG_UNBLOCK, &sigset, &oldset); - - memset(&new_act, 0, sizeof(new_act)); - sigemptyset(&new_act.sa_mask); - - if (sigsetjmp(jenv, 1)) - goto timed; - - new_act.sa_handler = sigjump; - sigaction(SIGALRM, &new_act, &alrm_act); - sigaction(SIGPIPE, &new_act, &pipe_act); - alarm(seconds); - if (read(pipes[0], argument, sizeof(struct stat)) == 0) { - errno = EFAULT; - ret = -1; - } - (void)alarm(0); - sigaction(SIGPIPE, &pipe_act, NULL); - sigaction(SIGALRM, &alrm_act, NULL); - - close(pipes[0]); - waitpid(pid, NULL, 0); - break; - } - return ret; -timed: - (void)alarm(0); - sigaction(SIGPIPE, &pipe_act, NULL); - sigaction(SIGALRM, &alrm_act, NULL); - if (waitpid(0, NULL, WNOHANG) == 0) - kill(pid, SIGKILL); - errno = ETIMEDOUT; -error: - return -1; -} -#endif - -/* - * End of timeout.c - */ diff --git src/timeout.h src/timeout.h deleted file mode 100644 index f372297..0000000 --- src/timeout.h +++ /dev/null @@ -1,45 +0,0 @@ -/* - * timout.h Advanced timeout handling for file system calls - * to avoid deadlocks on remote file shares. - * - * Version: 0.1 07-Sep-2011 Fink - * - * Copyright 2011 Werner Fink, 2011 SUSE LINUX Products GmbH, Germany. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * Author: Werner Fink , 2011 - */ - -#ifndef _TIMEOUT_H -#define _TIMEOUT_H - -#include "config.h" - -#ifndef WITH_TIMEOUT_STAT -# define WITH_TIMEOUT_STAT 0 -#endif - -#include -#include -#include -#include - -#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) -# ifndef restrict -# define restrict __restrict__ -# endif -#endif - -typedef int (*stat_t)(const char *, struct stat *); - -#if WITH_TIMEOUT_STAT > 0 -extern int timeout(stat_t, const char *, struct stat *restrict, time_t); -#else -# define timeout(func,path,buf,dummy) (func)((path),(buf)) -#endif - -#endif -- 2.26.2