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psmisc/0002-Use-new-statx-2-system-call-to-avoid-hangs-on-NFS.patch

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From 59144ef25a4bf0ecceb27e1c2dd2276de54555fe Mon Sep 17 00:00:00 2001
From: Werner Fink <werner@suse.de>
Date: Mon, 27 Apr 2020 16:44:17 +0200
Subject: [PATCH] Use new statx(2) system call to avoid hangs on NFS
Signed-off-by: Werner Fink <werner@suse.de>
---
Makefile.am | 4 +-
configure.ac | 38 ++----
src/fuser.c | 98 ++++---------
src/statx.c | 149 ++++++++++++++++++++
src/statx.h | 68 +++++++++
src/timeout.c | 372 --------------------------------------------------
src/timeout.h | 45 ------
7 files changed, 258 insertions(+), 516 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 d8c4619..a76799c 100644
--- Makefile.am
+++ Makefile.am
@@ -58,8 +58,8 @@ 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 d8d3366..81d3674 100644
--- configure.ac
+++ configure.ac
@@ -33,20 +33,6 @@ else
fi
AC_SUBST([SELINUX_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])
@@ -60,16 +46,20 @@ 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 "$enable_mountinfo_list" = "yes" -a -e /proc/self/mountinfo ; then
- AC_DEFINE([WITH_MOUNTINFO_LIST], [1], [Use list in /proc/self/mountinfo to replace stat calls])
-fi
+AC_CHECK_HEADERS([sys/syscall.h])
+AC_CHECK_DECLS([SYS_statx],
+ [has_syscall_statx="yes"],
+ [has_syscall_statx="no"],
+ [[#include <sys/syscall.h>]]
+)
+AC_CHECK_FUNCS([statx])
+# Check for linux specific statx(2) system call
+AC_SUBST([HAS_SYSCALL_STATX])
+AC_ARG_ENABLE([disable_statx],
+ [AS_HELP_STRING([--disable-statx], [Do not use linux specific statx(2) system call as replacement for stat(2), lstat(2), and fstat(2)])],
+ [enable_syscall_statx="no"],
+ [enable_syscall_statx=$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 1b58374..fc98790 100644
--- src/fuser.c
+++ src/fuser.c
@@ -63,7 +63,7 @@
#include "fuser.h"
#include "signals.h"
#include "i18n.h"
-#include "timeout.h"
+#include "statx.h"
#include "comm.h"
//#define DEBUG 1
@@ -118,10 +118,6 @@ static void clear_mntinfo(void) __attribute__ ((__destructor__));
static void init_mntinfo(void) __attribute__ ((__constructor__));
static int get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info);
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;
@@ -506,7 +502,7 @@ 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, &(this_name->st)) != 0 ||
find_mountpoint(this_name->filename, &mountinfo) != 0) {
if (errno == ENOENT)
fprintf(stderr,
@@ -1241,9 +1237,7 @@ 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;
@@ -1309,10 +1303,11 @@ 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)
@@ -1632,7 +1627,7 @@ 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, 256, "/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;
}
@@ -1679,7 +1674,7 @@ 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));
@@ -1734,7 +1729,7 @@ 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));
@@ -1832,11 +1827,11 @@ 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;
}
@@ -1874,7 +1869,7 @@ 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;
}
@@ -2009,7 +2004,7 @@ 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;
@@ -2042,7 +2037,7 @@ 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 */
@@ -2077,7 +2072,7 @@ 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 */
@@ -2124,7 +2119,7 @@ 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 */
@@ -2216,10 +2211,10 @@ 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 */
}
}
@@ -2231,7 +2226,7 @@ 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"),
mnt->mpoint, strerror(errno));
@@ -2240,7 +2235,7 @@ 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;
}
@@ -2290,7 +2285,7 @@ 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++;
@@ -2363,7 +2358,7 @@ 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));
@@ -2395,7 +2390,7 @@ 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));
@@ -2433,49 +2428,6 @@ 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 <config.h>
+#endif
+
+#ifndef HAVE_STATX
+# define _ASM_GENERIC_FCNTL_H /* Avoid collisions between asm/fcntl.h and bits/fcntl.h ! */
+# include <linux/fcntl.h> /* Definition of AT_* and AT_STATX_* constants ! */
+#endif
+#include <fcntl.h> /* Definition of AT_* constants */
+#include <sys/stat.h>
+#ifndef HAVE_STATX
+# ifndef STATX_TYPE
+# include <linux/stat.h> /* Provides 'struct statx' and STATX_* ! */
+# endif
+#endif
+#include <sys/sysmacros.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+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 <linux/fcntl.h> /* Definition of AT_* and AT_STATX_* constants ! */
+# ifndef STATX_TYPE
+# include <linux/stat.h> /* 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 ca4a7cd..0000000
--- src/timeout.c
+++ /dev/null
@@ -1,372 +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 <werner@suse.de>, 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 <errno.h>
-#include <setjmp.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/select.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#if USE_SOCKETPAIR
-# include <sys/socket.h>
-# include <netdb.h>
-# include <netinet/in.h>
-# 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 <wait.h>
-
-#include "timeout.h"
-
-#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L)
-# ifndef destructor
-# define destructor __destructor__
-# endif
-# ifndef constructor
-# define constructor __constructor__
-# endif
-# ifndef packed
-# define packed __packed__
-# 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];
-} attribute((packed)) 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 <werner@suse.de>, 2011
- */
-
-#ifndef _TIMEOUT_H
-#define _TIMEOUT_H
-
-#include "config.h"
-
-#ifndef WITH_TIMEOUT_STAT
-# define WITH_TIMEOUT_STAT 0
-#endif
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <time.h>
-#include <limits.h>
-
-#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
--
2.25.0
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