Refer to ZED's scripts as ZEDLETs

The executables invoked by the ZED in response to a given zevent
have been generically referred to as "scripts".  By convention,
these scripts have aimed to be /bin/sh compatible for reasons of
portability and comprehensibility.  However, the ZED only requires
they be executable and (ideally) capable of reading environment
variables.  As such, these scripts are now referred to as ZEDLETs
(ZFS Event Daemon Linkage for Executable Tasks).

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2735
This commit is contained in:
Chris Dunlap 2014-09-19 11:10:28 -07:00 committed by Brian Behlendorf
parent 8cb8cf91df
commit dcca723ace
14 changed files with 93 additions and 92 deletions

View File

@ -2,7 +2,7 @@
#
# Log all environment variables to ZED_DEBUG_LOG.
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
# Override the default umask to restrict access to a newly-created logfile.
umask 077

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@ -2,7 +2,7 @@
#
# Log the zevent via syslog.
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
logger -t "${ZED_SYSLOG_TAG:=zed}" -p "${ZED_SYSLOG_PRIORITY:=daemon.notice}" \
eid="${ZEVENT_EID}" class="${ZEVENT_SUBCLASS}" \

View File

@ -14,7 +14,7 @@
# State File Format:
# POOL;TIME_OF_LAST_EMAIL
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
test -n "${ZEVENT_POOL}" || exit 5
test -n "${ZEVENT_SUBCLASS}" || exit 5

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@ -12,7 +12,7 @@
# 2: email suppressed
# 3: missing executable
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
# Only send email if ZED_EMAIL has been configured.
test -n "${ZED_EMAIL}" || exit 2

View File

@ -14,7 +14,7 @@
# State File Format:
# POOL;VDEV_PATH;TIME_OF_LAST_EMAIL
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
test -n "${ZEVENT_POOL}" || exit 5
test -n "${ZEVENT_SUBCLASS}" || exit 5

View File

@ -28,7 +28,7 @@
# 4: unsupported event class
# 5: internal error
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
test -n "${ZEVENT_POOL}" || exit 5
test -n "${ZEVENT_SUBCLASS}" || exit 5

View File

@ -12,7 +12,7 @@
# 4: unsupported event class
# 5: internal error
#
test -f "${ZED_SCRIPT_DIR}/zed.rc" && . "${ZED_SCRIPT_DIR}/zed.rc"
test -f "${ZED_ZEDLET_DIR}/zed.rc" && . "${ZED_ZEDLET_DIR}/zed.rc"
test -n "${ZEVENT_POOL}" || exit 5
test -n "${ZEVENT_SUBCLASS}" || exit 5

View File

@ -43,9 +43,9 @@
#define ZED_STATE_FILE RUNSTATEDIR "/zed.state"
/*
* Absolute path for the default zed script directory.
* Absolute path for the default zed zedlet directory.
*/
#define ZED_SCRIPT_DIR SYSCONFDIR "/zfs/zed.d"
#define ZED_ZEDLET_DIR SYSCONFDIR "/zfs/zed.d"
/*
* Reserved for future use.

View File

@ -58,7 +58,7 @@ zed_conf_create(void)
zcp->syslog_facility = LOG_DAEMON;
zcp->min_events = ZED_MIN_EVENTS;
zcp->max_events = ZED_MAX_EVENTS;
zcp->scripts = NULL; /* created via zed_conf_scan_dir() */
zcp->zedlets = NULL; /* created via zed_conf_scan_dir() */
zcp->state_fd = -1; /* opened via zed_conf_open_state() */
zcp->zfs_hdl = NULL; /* opened via zed_event_init() */
zcp->zevent_fd = -1; /* opened via zed_event_init() */
@ -69,7 +69,7 @@ zed_conf_create(void)
if (!(zcp->pid_file = strdup(ZED_PID_FILE)))
goto nomem;
if (!(zcp->script_dir = strdup(ZED_SCRIPT_DIR)))
if (!(zcp->zedlet_dir = strdup(ZED_ZEDLET_DIR)))
goto nomem;
if (!(zcp->state_file = strdup(ZED_STATE_FILE)))
@ -111,14 +111,14 @@ zed_conf_destroy(struct zed_conf *zcp)
if (zcp->pid_file)
free(zcp->pid_file);
if (zcp->script_dir)
free(zcp->script_dir);
if (zcp->zedlet_dir)
free(zcp->zedlet_dir);
if (zcp->state_file)
free(zcp->state_file);
if (zcp->scripts)
zed_strings_destroy(zcp->scripts);
if (zcp->zedlets)
zed_strings_destroy(zcp->zedlets);
free(zcp);
}
@ -161,7 +161,7 @@ _zed_conf_display_help(const char *prog, int got_err)
"Read configuration from FILE.", ZED_CONF_FILE);
#endif
fprintf(fp, "%*c%*s %s [%s]\n", w1, 0x20, -w2, "-d DIR",
"Read enabled scripts from DIR.", ZED_SCRIPT_DIR);
"Read enabled ZEDLETs from DIR.", ZED_ZEDLET_DIR);
fprintf(fp, "%*c%*s %s [%s]\n", w1, 0x20, -w2, "-p FILE",
"Write daemon's PID to FILE.", ZED_PID_FILE);
fprintf(fp, "%*c%*s %s [%s]\n", w1, 0x20, -w2, "-s FILE",
@ -269,7 +269,7 @@ zed_conf_parse_opts(struct zed_conf *zcp, int argc, char **argv)
_zed_conf_parse_path(&zcp->conf_file, optarg);
break;
case 'd':
_zed_conf_parse_path(&zcp->script_dir, optarg);
_zed_conf_parse_path(&zcp->zedlet_dir, optarg);
break;
case 'p':
_zed_conf_parse_path(&zcp->pid_file, optarg);
@ -318,19 +318,19 @@ zed_conf_parse_file(struct zed_conf *zcp)
}
/*
* Scan the [zcp] script_dir for files to exec based on the event class.
* Scan the [zcp] zedlet_dir for files to exec based on the event class.
* Files must be executable by user, but not writable by group or other.
* Dotfiles are ignored.
*
* Return 0 on success with an updated set of scripts,
* Return 0 on success with an updated set of zedlets,
* or -1 on error with errno set.
*
* FIXME: Check if script_dir and all parent dirs are secure.
* FIXME: Check if zedlet_dir and all parent dirs are secure.
*/
int
zed_conf_scan_dir(struct zed_conf *zcp)
{
zed_strings_t *scripts;
zed_strings_t *zedlets;
DIR *dirp;
struct dirent *direntp;
char pathname[PATH_MAX];
@ -339,23 +339,23 @@ zed_conf_scan_dir(struct zed_conf *zcp)
if (!zcp) {
errno = EINVAL;
zed_log_msg(LOG_ERR, "Failed to scan script dir: %s",
zed_log_msg(LOG_ERR, "Failed to scan zedlet dir: %s",
strerror(errno));
return (-1);
}
scripts = zed_strings_create();
if (!scripts) {
zedlets = zed_strings_create();
if (!zedlets) {
errno = ENOMEM;
zed_log_msg(LOG_WARNING, "Failed to scan dir \"%s\": %s",
zcp->script_dir, strerror(errno));
zcp->zedlet_dir, strerror(errno));
return (-1);
}
dirp = opendir(zcp->script_dir);
dirp = opendir(zcp->zedlet_dir);
if (!dirp) {
int errno_bak = errno;
zed_log_msg(LOG_WARNING, "Failed to open dir \"%s\": %s",
zcp->script_dir, strerror(errno));
zed_strings_destroy(scripts);
zcp->zedlet_dir, strerror(errno));
zed_strings_destroy(zedlets);
errno = errno_bak;
return (-1);
}
@ -364,7 +364,7 @@ zed_conf_scan_dir(struct zed_conf *zcp)
continue;
n = snprintf(pathname, sizeof (pathname),
"%s/%s", zcp->script_dir, direntp->d_name);
"%s/%s", zcp->zedlet_dir, direntp->d_name);
if ((n < 0) || (n >= sizeof (pathname))) {
zed_log_msg(LOG_WARNING, "Failed to stat \"%s\": %s",
direntp->d_name, strerror(ENAMETOOLONG));
@ -405,7 +405,7 @@ zed_conf_scan_dir(struct zed_conf *zcp)
direntp->d_name);
continue;
}
if (zed_strings_add(scripts, direntp->d_name) < 0) {
if (zed_strings_add(zedlets, direntp->d_name) < 0) {
zed_log_msg(LOG_WARNING,
"Failed to register \"%s\": %s",
direntp->d_name, strerror(errno));
@ -413,20 +413,20 @@ zed_conf_scan_dir(struct zed_conf *zcp)
}
if (zcp->do_verbose)
zed_log_msg(LOG_INFO,
"Registered script \"%s\"", direntp->d_name);
"Registered zedlet \"%s\"", direntp->d_name);
}
if (closedir(dirp) < 0) {
int errno_bak = errno;
zed_log_msg(LOG_WARNING, "Failed to close dir \"%s\": %s",
zcp->script_dir, strerror(errno));
zed_strings_destroy(scripts);
zcp->zedlet_dir, strerror(errno));
zed_strings_destroy(zedlets);
errno = errno_bak;
return (-1);
}
if (zcp->scripts)
zed_strings_destroy(zcp->scripts);
if (zcp->zedlets)
zed_strings_destroy(zcp->zedlets);
zcp->scripts = scripts;
zcp->zedlets = zedlets;
return (0);
}

View File

@ -42,8 +42,8 @@ struct zed_conf {
int max_events; /* RESERVED FOR FUTURE USE */
char *conf_file; /* abs path to config file */
char *pid_file; /* abs path to pid file */
char *script_dir; /* abs path to script dir */
zed_strings_t *scripts; /* names of enabled scripts */
char *zedlet_dir; /* abs path to zedlet dir */
zed_strings_t *zedlets; /* names of enabled zedlets */
char *state_file; /* abs path to state file */
int state_fd; /* fd to state file */
libzfs_handle_t *zfs_hdl; /* handle to libzfs */

View File

@ -814,7 +814,7 @@ zed_event_service(struct zed_conf *zcp)
_zed_event_add_var(eid, zsp, "%s%s=%d",
ZED_VAR_PREFIX, "PID", (int) getpid());
_zed_event_add_var(eid, zsp, "%s%s=%s",
ZED_VAR_PREFIX, "SCRIPT_DIR", zcp->script_dir);
ZED_VAR_PREFIX, "ZEDLET_DIR", zcp->zedlet_dir);
subclass = _zed_event_get_subclass(class);
_zed_event_add_var(eid, zsp, "%s%s=%s",
@ -823,7 +823,7 @@ zed_event_service(struct zed_conf *zcp)
_zed_event_add_time_strings(eid, zsp, etime);
zed_exec_process(eid, class, subclass,
zcp->script_dir, zcp->scripts, zsp, zcp->zevent_fd);
zcp->zedlet_dir, zcp->zedlets, zsp, zcp->zevent_fd);
zed_conf_write_state(zcp, eid, etime);

View File

@ -156,13 +156,13 @@ restart:
}
/*
* Process the event [eid] by synchronously invoking all scripts with a
* Process the event [eid] by synchronously invoking all zedlets with a
* matching class prefix.
*
* Each executable in [scripts] from the directory [dir] is matched against
* Each executable in [zedlets] from the directory [dir] is matched against
* the event's [class], [subclass], and the "all" class (which matches
* all events). Every script with a matching class prefix is invoked.
* The NAME=VALUE strings in [envs] will be passed to the script as
* all events). Every zedlet with a matching class prefix is invoked.
* The NAME=VALUE strings in [envs] will be passed to the zedlet as
* environment variables.
*
* The file descriptor [zfd] is the zevent_fd used to track the
@ -172,16 +172,16 @@ restart:
*/
int
zed_exec_process(uint64_t eid, const char *class, const char *subclass,
const char *dir, zed_strings_t *scripts, zed_strings_t *envs, int zfd)
const char *dir, zed_strings_t *zedlets, zed_strings_t *envs, int zfd)
{
const char *class_strings[4];
const char *allclass = "all";
const char **csp;
const char *s;
const char *z;
char **e;
int n;
if (!dir || !scripts || !envs || zfd < 0)
if (!dir || !zedlets || !envs || zfd < 0)
return (-1);
csp = class_strings;
@ -199,11 +199,11 @@ zed_exec_process(uint64_t eid, const char *class, const char *subclass,
e = _zed_exec_create_env(envs);
for (s = zed_strings_first(scripts); s; s = zed_strings_next(scripts)) {
for (z = zed_strings_first(zedlets); z; z = zed_strings_next(zedlets)) {
for (csp = class_strings; *csp; csp++) {
n = strlen(*csp);
if ((strncmp(s, *csp, n) == 0) && !isalpha(s[n]))
_zed_exec_fork_child(eid, dir, s, e, zfd);
if ((strncmp(z, *csp, n) == 0) && !isalpha(z[n]))
_zed_exec_fork_child(eid, dir, z, e, zfd);
}
}
free(e);

View File

@ -30,7 +30,7 @@
#include <stdint.h>
int zed_exec_process(uint64_t eid, const char *class, const char *subclass,
const char *dir, zed_strings_t *scripts, zed_strings_t *envs,
const char *dir, zed_strings_t *zedlets, zed_strings_t *envs,
int zevent_fd);
#endif /* !ZED_EXEC_H */

View File

@ -24,13 +24,13 @@
.TH ZED 8 "Octember 1, 2013" "ZFS on Linux" "System Administration Commands"
.SH NAME
zed \- ZFS Event Daemon
ZED \- ZFS Event Daemon
.SH SYNOPSIS
.HP
.B zed
.\" [\fB\-c\fR \fIconfigfile\fR]
[\fB\-d\fR \fIscriptdir\fR]
[\fB\-d\fR \fIzedletdir\fR]
[\fB\-f\fR]
[\fB\-F\fR]
[\fB\-h\fR]
@ -44,9 +44,10 @@ zed \- ZFS Event Daemon
.SH DESCRIPTION
.PP
\fBzed\fR (ZFS Event Daemon) monitors events generated by the ZFS kernel
module. When a ZFS event (zevent) is posted, \fBzed\fR will run any scripts
that have been enabled for the corresponding zevent class.
\fBZED\fR (ZFS Event Daemon) monitors events generated by the ZFS kernel
module. When a zevent (ZFS Event) is posted, \fBZED\fR will run any ZEDLETs
(ZFS Event Daemon Linkage for Executable Tasks) that have been enabled for the
corresponding zevent class.
.SH OPTIONS
.TP
@ -81,8 +82,8 @@ to be reprocessed.
.\" .BI \-c\ configfile
.\" Read the configuration from the specified file.
.TP
.BI \-d\ scriptdir
Read the enabled scripts from the specified directory.
.BI \-d\ zedletdir
Read the enabled ZEDLETs from the specified directory.
.TP
.BI \-p\ pidfile
Write the daemon's process ID to the specified file.
@ -92,7 +93,7 @@ Write the daemon's state to the specified file.
.SH ZEVENTS
.PP
A zevent is comprised of a list of name/value pairs (nvpairs). Each zevent
A zevent is comprised of a list of nvpairs (name/value pairs). Each zevent
contains an EID (Event IDentifier) that uniquely identifies it throughout
the lifetime of the loaded ZFS kernel module; this EID is a monotonically
increasing integer that resets to 1 each time the kernel module is loaded.
@ -105,29 +106,29 @@ their associated lists of nvpairs) using the "\fBzpool events \-v\fR" command.
.SH CONFIGURATION
.PP
The scripts to be invoked in response to zevents are located in the
enabled-scripts directory. These can be symlinked or copied from the
installed-scripts directory; symlinks allow for automatic updates from the
installed scripts, whereas copies preserve local modifications. As a security
measure, scripts must be owned by root. They must have execute permissions
for the user, but they must not have write permissions for group or other.
Dotfiles are ignored.
ZEDLETs to be invoked in response to zevents are located in the
\fIenabled-zedlets\fR directory. These can be symlinked or copied from the
\fIinstalled-zedlets\fR directory; symlinks allow for automatic updates
from the installed ZEDLETs, whereas copies preserve local modifications.
As a security measure, ZEDLETs must be owned by root. They must have
execute permissions for the user, but they must not have write permissions
for group or other. Dotfiles are ignored.
.PP
Scripts are named after the zevent class for which they should be invoked.
In particular, a script will be invoked for a given zevent if either its
ZEDLETs are named after the zevent class for which they should be invoked.
In particular, a ZEDLET will be invoked for a given zevent if either its
class or subclass string is a prefix of its filename (and is followed by
a non-alphabetic character). As a special case, the prefix "all" matches
all zevents. Multiple scripts may be invoked for a given zevent.
all zevents. Multiple ZEDLETs may be invoked for a given zevent.
.SH SCRIPTS
.SH ZEDLETS
.PP
Scripts should be written under the presumption they can be invoked
concurrently, and they should use appropriate locking to access any shared
resources. Common variables used by the scripts can be stored in the default
rc file which is sourced by the scripts; these variables should be prefixed
with "ZED_".
ZEDLETs are executables invoked by the ZED in response to a given zevent.
They should be written under the presumption they can be invoked concurrently,
and they should use appropriate locking to access any shared resources.
Common variables used by ZEDLETs can be stored in the default rc file which
is sourced by scripts; these variables should be prefixed with "ZED_".
.PP
The zevent nvpairs are passed to the scripts as environment variables.
The zevent nvpairs are passed to ZEDLETs as environment variables.
Each nvpair name is converted to an environment variable in the following
manner: 1) it is prefixed with "ZEVENT_", 2) it is converted to uppercase,
and 3) each non-alphanumeric character is converted to an underscore.
@ -171,12 +172,12 @@ ZED_PID
The daemon's process ID.
.TP
.B
ZED_SCRIPT_DIR
The daemon's current enabled-scripts directory.
ZED_ZEDLET_DIR
The daemon's current \fIenabled-zedlets\fR directory.
.TP
.B
ZFS_ALIAS
The ZFS alias (name-ver-rel) string used to build the daemon.
The ZFS alias (\fIname-version-release\fR) string used to build the daemon.
.TP
.B
ZFS_VERSION
@ -186,10 +187,10 @@ The ZFS version used to build the daemon.
ZFS_RELEASE
The ZFS release used to build the daemon.
.PP
Scripts may need to call other ZFS commands. The installation paths of
ZEDLETs may need to call other ZFS commands. The installation paths of
the following executables are defined: \fBZDB\fR, \fBZED\fR, \fBZFS\fR,
\fBZINJECT\fR, and \fBZPOOL\fR. These variables can be overridden in the
zed.rc if needed.
rc file if needed.
.SH FILES
.\" .TP
@ -197,13 +198,13 @@ zed.rc if needed.
.\" The default configuration file for the daemon.
.TP
.I @sysconfdir@/zfs/zed.d
The default directory for enabled scripts.
The default directory for enabled ZEDLETs.
.TP
.I @sysconfdir@/zfs/zed.d/zed.rc
The default rc file for common variables used by the scripts.
The default rc file for common variables used by ZEDLETs.
.TP
.I @libexecdir@/zfs/zed.d
The default directory for installed scripts.
The default directory for installed ZEDLETs.
.TP
.I @runstatedir@/zed.pid
The default file containing the daemon's process ID.
@ -214,14 +215,14 @@ The default file containing the daemon's state.
.SH SIGNALS
.TP
.B HUP
Reconfigure the daemon and rescan the directory for enabled scripts.
Reconfigure the daemon and rescan the directory for enabled ZEDLETs.
.TP
.B TERM
Terminate the daemon.
.SH NOTES
.PP
\fBzed\fR requires root privileges.
\fBZED\fR requires root privileges.
.\" Do not taunt zed.
.SH BUGS
@ -229,16 +230,16 @@ Terminate the daemon.
Events are processed synchronously by a single thread. This can delay the
processing of simultaneous zevents.
.PP
There is no maximum timeout for script execution. Consequently, a misbehaving
script can delay the processing of subsequent zevents.
There is no maximum timeout for ZEDLET execution. Consequently, a misbehaving
ZEDLET can delay the processing of subsequent zevents.
.PP
The ownership and permissions of the enabled-scripts directory (along
The ownership and permissions of the \fIenabled-zedlets\fR directory (along
with all parent directories) are not checked. If any of these directories
are improperly owned or permissioned, an unprivileged user could insert a
script to be executed as root. The requirement that scripts be owned by
ZEDLET to be executed as root. The requirement that ZEDLETs be owned by
root mitigates this to some extent.
.PP
Scripts are unable to return state/status information to the kernel.
ZEDLETs are unable to return state/status information to the kernel.
.PP
Some zevent nvpair types are not handled. These are denoted by zevent
environment variables having a "_NOT_IMPLEMENTED_" value.
@ -257,7 +258,7 @@ Copyright (C) 2013\-2014 Lawrence Livermore National Security, LLC.
.SH LICENSE
.PP
\fBzed\fR (ZFS Event Daemon) is distributed under the terms of the
\fBZED\fR (ZFS Event Daemon) is distributed under the terms of the
Common Development and Distribution License (CDDL\-1.0).
.SH SEE ALSO