[lvm-devel] master - log: separate output and make it possible to use given FDs
Peter Rajnoha
prajnoha at fedoraproject.org
Tue Aug 9 17:39:33 UTC 2016
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=06ce9b4e4238da58d6c2acda7878dbc51245a8fc
Commit: 06ce9b4e4238da58d6c2acda7878dbc51245a8fc
Parent: bb9789f2b3404893dcb92cfc2d1eeec002c90140
Author: Peter Rajnoha <prajnoha at redhat.com>
AuthorDate: Fri Jul 8 16:47:51 2016 +0200
Committer: Peter Rajnoha <prajnoha at redhat.com>
CommitterDate: Tue Aug 9 18:24:45 2016 +0200
log: separate output and make it possible to use given FDs
Currently, the output is separated in 3 parts and each part can go into
a separate and user-defined file descriptor:
- common output (stdout by default, customizable by LVM_OUT_FD environment variable)
- error output (stderr by default, customizable by LVM_ERR_FD environment variable)
- report output (stdout by default, customizable by LVM_REPORT_FD environment variable)
For example, each type of output goes to different output file:
[0] fedora/~ # export LVM_REPORT_FD=3
[0] fedora/~ # lvs fedora vg/abc 1>out 2>err 3>report
[0] fedora/~ # cat out
[0] fedora/~ # cat err
Volume group "vg" not found
Cannot process volume group vg
[0] fedora/~ # cat report
LV VG Attr LSize Layout Role CTime
root fedora -wi-ao---- 19.00g linear public Wed May 27 2015 08:09:21
swap fedora -wi-ao---- 500.00m linear public Wed May 27 2015 08:09:21
Another example in LVM shell where the report goes to "report" file:
[0] fedora/~ # export LVM_REPORT_FD=3
[0] fedora/~ # lvm 3>report
(in lvm shell)
lvm> vgs
(content of "report" file)
[1] fedora/~ # cat report
VG #PV #LV #SN Attr VSize VFree
fedora 1 2 0 wz--n- 19.49g 0
(in lvm shell)
lvm> lvs
(content of "report" file)
[1] fedora/~ # cat report
VG #PV #LV #SN Attr VSize VFree
fedora 1 2 0 wz--n- 19.49g 0
LV VG Attr LSize Layout Role CTime
root fedora -wi-ao---- 19.00g linear public Wed May 27 2015 08:09:21
swap fedora -wi-ao---- 500.00m linear public Wed May 27 2015 08:09:21
---
lib/commands/toolcontext.c | 50 ++-----------
lib/log/log.c | 172 +++++++++++++++++++++++++++++++++++++++++---
lib/log/lvm-logging.h | 5 ++
lib/misc/lvm-file.h | 6 ++
man/lvm.8.in | 9 +++
tools/lvmcmdline.c | 62 ++++++++++++++--
6 files changed, 245 insertions(+), 59 deletions(-)
diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c
index d3bd5bc..82e990e 100644
--- a/lib/commands/toolcontext.c
+++ b/lib/commands/toolcontext.c
@@ -1650,37 +1650,6 @@ static void _init_globals(struct cmd_context *cmd)
}
/*
- * Close and reopen stream on file descriptor fd.
- */
-static int _reopen_stream(FILE *stream, int fd, const char *mode, const char *name, FILE **new_stream)
-{
- int fd_copy, new_fd;
-
- if ((fd_copy = dup(fd)) < 0) {
- log_sys_error("dup", name);
- return 0;
- }
-
- if (fclose(stream))
- log_sys_error("fclose", name);
-
- if ((new_fd = dup2(fd_copy, fd)) < 0)
- log_sys_error("dup2", name);
- else if (new_fd != fd)
- log_error("dup2(%d, %d) returned %d", fd_copy, fd, new_fd);
-
- if (close(fd_copy) < 0)
- log_sys_error("close", name);
-
- if (!(*new_stream = fdopen(fd, mode))) {
- log_sys_error("fdopen", name);
- return 0;
- }
-
- return 1;
-}
-
-/*
* init_connections();
* _init_lvmetad();
* lvmetad_disconnect(); (close previous connection)
@@ -1835,7 +1804,6 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
unsigned set_filters)
{
struct cmd_context *cmd;
- FILE *new_stream;
int flags;
#ifdef M_MMAP_MAX
@@ -1885,9 +1853,8 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
if (is_valid_fd(STDIN_FILENO) &&
((flags = fcntl(STDIN_FILENO, F_GETFL)) > 0) &&
(flags & O_ACCMODE) != O_WRONLY) {
- if (!_reopen_stream(stdin, STDIN_FILENO, "r", "stdin", &new_stream))
+ if (!reopen_standard_stream(&stdin, "r"))
goto_out;
- stdin = new_stream;
if (setvbuf(stdin, cmd->linebuffer, _IOLBF, linebuffer_size)) {
log_sys_error("setvbuf", "");
goto out;
@@ -1897,9 +1864,8 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
if (is_valid_fd(STDOUT_FILENO) &&
((flags = fcntl(STDOUT_FILENO, F_GETFL)) > 0) &&
(flags & O_ACCMODE) != O_RDONLY) {
- if (!_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout", &new_stream))
+ if (!reopen_standard_stream(&stdout, "w"))
goto_out;
- stdout = new_stream;
if (setvbuf(stdout, cmd->linebuffer + linebuffer_size,
_IOLBF, linebuffer_size)) {
log_sys_error("setvbuf", "");
@@ -1911,7 +1877,6 @@ struct cmd_context *create_toolcontext(unsigned is_long_lived,
/* Without buffering, must not use stdin/stdout */
init_silent(1);
#endif
-
/*
* Environment variable LVM_SYSTEM_DIR overrides this below.
*/
@@ -2227,7 +2192,6 @@ int refresh_toolcontext(struct cmd_context *cmd)
void destroy_toolcontext(struct cmd_context *cmd)
{
struct dm_config_tree *cft_cmdline;
- FILE *new_stream;
int flags;
if (cmd->dump_filter && cmd->filter && cmd->filter->dump &&
@@ -2266,20 +2230,18 @@ void destroy_toolcontext(struct cmd_context *cmd)
if (is_valid_fd(STDIN_FILENO) &&
((flags = fcntl(STDIN_FILENO, F_GETFL)) > 0) &&
(flags & O_ACCMODE) != O_WRONLY) {
- if (_reopen_stream(stdin, STDIN_FILENO, "r", "stdin", &new_stream)) {
- stdin = new_stream;
+ if (reopen_standard_stream(&stdin, "r"))
setlinebuf(stdin);
- } else
+ else
cmd->linebuffer = NULL; /* Leave buffer in place (deliberate leak) */
}
if (is_valid_fd(STDOUT_FILENO) &&
((flags = fcntl(STDOUT_FILENO, F_GETFL)) > 0) &&
(flags & O_ACCMODE) != O_RDONLY) {
- if (_reopen_stream(stdout, STDOUT_FILENO, "w", "stdout", &new_stream)) {
- stdout = new_stream;
+ if (reopen_standard_stream(&stdout, "w"))
setlinebuf(stdout);
- } else
+ else
cmd->linebuffer = NULL; /* Leave buffer in place (deliberate leak) */
}
diff --git a/lib/log/log.c b/lib/log/log.c
index 6d5fc59..d021ffe 100644
--- a/lib/log/log.c
+++ b/lib/log/log.c
@@ -18,6 +18,7 @@
#include "memlock.h"
#include "defaults.h"
#include "report.h"
+#include "lvm-file.h"
#include <stdio.h>
#include <stdarg.h>
@@ -59,6 +60,154 @@ static log_report_t _log_report = {
.object_group = NULL
};
+#define LOG_STREAM_BUFFER_SIZE 4096
+
+struct log_stream_item {
+ FILE *stream;
+ char *buffer;
+};
+
+struct log_stream {
+ struct log_stream_item out;
+ struct log_stream_item err;
+ struct log_stream_item report;
+} _log_stream = {{NULL, NULL},
+ {NULL, NULL},
+ {NULL, NULL}};
+
+#define out_stream (_log_stream.out.stream ? : stdout)
+#define err_stream (_log_stream.err.stream ? : stderr)
+#define report_stream (_log_stream.report.stream ? : stdout)
+
+static int _set_custom_log_stream(struct log_stream_item *stream_item, int custom_fd)
+{
+ FILE *final_stream = NULL;
+ int flags;
+ int r = 1;
+
+ if (custom_fd < 0)
+ goto out;
+
+ if (is_valid_fd(custom_fd)) {
+ if ((flags = fcntl(custom_fd, F_GETFL)) > 0) {
+ if ((flags & O_ACCMODE) == O_RDONLY) {
+ log_error("File descriptor %d already open in read-only "
+ "mode, expected write-only or read-write mode.",
+ (int) custom_fd);
+ r = 0;
+ goto out;
+ }
+ }
+
+ if (custom_fd == STDIN_FILENO) {
+ log_error("Can't set standard input for log output.");
+ r = 0;
+ goto out;
+ }
+
+ if (custom_fd == STDOUT_FILENO) {
+ final_stream = stdout;
+ goto out;
+ }
+
+ if (custom_fd == STDERR_FILENO) {
+ final_stream = stderr;
+ goto out;
+ }
+ }
+
+ if (!(final_stream = fdopen(custom_fd, "w"))) {
+ log_error("Failed to open stream for file descriptor %d.",
+ (int) custom_fd);
+ r = 0;
+ goto out;
+ }
+
+ if (!(stream_item->buffer = dm_malloc(LOG_STREAM_BUFFER_SIZE))) {
+ log_error("Failed to allocate buffer for stream on file "
+ "descriptor %d.", (int) custom_fd);
+ } else {
+ if (setvbuf(final_stream, stream_item->buffer, _IOLBF, LOG_STREAM_BUFFER_SIZE)) {
+ log_sys_error("setvbuf", "");
+ dm_free(stream_item->buffer);
+ stream_item->buffer = NULL;
+ }
+ }
+out:
+ stream_item->stream = final_stream;
+ return r;
+}
+
+int init_custom_log_streams(struct custom_fds *custom_fds)
+{
+ return _set_custom_log_stream(&_log_stream.out, custom_fds->out) &&
+ _set_custom_log_stream(&_log_stream.err, custom_fds->err) &&
+ _set_custom_log_stream(&_log_stream.report, custom_fds->report);
+}
+
+static void _check_and_replace_standard_log_streams(FILE *old_stream, FILE *new_stream)
+{
+ if (_log_stream.out.stream == old_stream)
+ _log_stream.out.stream = new_stream;
+
+ if (_log_stream.err.stream == old_stream)
+ _log_stream.err.stream = new_stream;
+
+ if (_log_stream.report.stream == old_stream)
+ _log_stream.report.stream = new_stream;
+}
+
+/*
+ * Close and reopen standard stream on file descriptor fd.
+ */
+int reopen_standard_stream(FILE **stream, const char *mode)
+{
+ int fd, fd_copy, new_fd;
+ const char *name;
+ FILE *old_stream = *stream;
+ FILE *new_stream;
+
+ if (old_stream == stdin) {
+ fd = STDIN_FILENO;
+ name = "stdin";
+ } else if (old_stream == stdout) {
+ fd = STDOUT_FILENO;
+ name = "stdout";
+ } else if (old_stream == stderr) {
+ fd = STDERR_FILENO;
+ name = "stderr";
+ } else {
+ log_error(INTERNAL_ERROR "reopen_standard_stream called on non-standard stream");
+ return 0;
+ }
+
+ if ((fd_copy = dup(fd)) < 0) {
+ log_sys_error("dup", name);
+ return 0;
+ }
+
+ if (fclose(old_stream))
+ log_sys_error("fclose", name);
+
+ if ((new_fd = dup2(fd_copy, fd)) < 0)
+ log_sys_error("dup2", name);
+ else if (new_fd != fd)
+ log_error("dup2(%d, %d) returned %d", fd_copy, fd, new_fd);
+
+ if (close(fd_copy) < 0)
+ log_sys_error("close", name);
+
+ if (!(new_stream = fdopen(fd, mode))) {
+ log_sys_error("fdopen", name);
+ return 0;
+ }
+
+ _check_and_replace_standard_log_streams(old_stream, new_stream);
+
+ *stream = new_stream;
+ return 1;
+}
+
void init_log_fn(lvm2_log_fn_t log_fn)
{
_lvm2_log_fn = log_fn;
@@ -207,10 +356,10 @@ void fin_log(void)
if (_log_to_file) {
if (dm_fclose(_log_file)) {
if (errno)
- fprintf(stderr, "failed to write log file: %s\n",
+ fprintf(err_stream, "failed to write log file: %s\n",
strerror(errno));
else
- fprintf(stderr, "failed to write log file\n");
+ fprintf(err_stream, "failed to write log file\n");
}
_log_to_file = 0;
@@ -378,8 +527,8 @@ static void _vprint_log(int level, const char *file, int line, int dm_errno_or_c
/* When newer glibc returns >= sizeof(locn), we will just log what
* has fit into buffer, it's '\0' terminated string */
if (n < 0) {
- fprintf(stderr, _("vsnprintf failed: skipping external "
- "logging function"));
+ fprintf(err_stream, _("vsnprintf failed: skipping external "
+ "logging function"));
goto log_it;
}
}
@@ -426,7 +575,7 @@ static void _vprint_log(int level, const char *file, int line, int dm_errno_or_c
_log_report.object_name, _log_report.object_id,
_log_report.object_group, _log_report.object_group_id,
message, _lvm_errno, 0))
- fprintf(stderr, _("failed to report cmdstatus"));
+ fprintf(err_stream, _("failed to report cmdstatus"));
else
logged_via_report = 1;
@@ -468,10 +617,10 @@ static void _vprint_log(int level, const char *file, int line, int dm_errno_or_c
break;
/* fall through */
default:
- /* Typically only log_warn goes to stdout */
- stream = (use_stderr || (level != _LOG_WARN)) ? stderr : stdout;
- if (stream == stderr)
- fflush(stdout);
+ /* Typically only log_warn goes to out_stream */
+ stream = (use_stderr || (level != _LOG_WARN)) ? err_stream : out_stream;
+ if (stream == err_stream)
+ fflush(out_stream);
fprintf(stream, "%s%s%s%s", buf, log_command_name(),
_msg_prefix, indent_spaces);
vfprintf(stream, trformat, ap);
@@ -556,6 +705,7 @@ void print_log(int level, const char *file, int line, int dm_errno_or_class,
void print_log_libdm(int level, const char *file, int line, int dm_errno_or_class,
const char *format, ...)
{
+ FILE *orig_out_stream = out_stream;
va_list ap;
/*
@@ -567,9 +717,13 @@ void print_log_libdm(int level, const char *file, int line, int dm_errno_or_clas
((level & ~(_LOG_STDERR|_LOG_ONCE|_LOG_BYPASS_REPORT)) == _LOG_WARN))
level |= _LOG_BYPASS_REPORT;
+ _log_stream.out.stream = report_stream;
+
va_start(ap, format);
_vprint_log(level, file, line, dm_errno_or_class, format, ap);
va_end(ap);
+
+ _log_stream.out.stream = orig_out_stream;
}
log_report_t log_get_report_state(void)
diff --git a/lib/log/lvm-logging.h b/lib/log/lvm-logging.h
index 4101bc8..7ddbf2c 100644
--- a/lib/log/lvm-logging.h
+++ b/lib/log/lvm-logging.h
@@ -16,6 +16,8 @@
#ifndef _LVM_LOGGING_H
#define _LVM_LOGGING_H
+#include "lvm-file.h"
+
__attribute__ ((format(printf, 5, 6)))
void print_log(int level, const char *file, int line, int dm_errno_or_class,
const char *format, ...);
@@ -35,6 +37,9 @@ void print_log_libdm(int level, const char *file, int line, int dm_errno_or_clas
#include "log.h"
+int init_custom_log_streams(struct custom_fds *custom_fds);
+int reopen_standard_stream(FILE **stream, const char *mode);
+
typedef void (*lvm2_log_fn_t) (int level, const char *file, int line,
int dm_errno_or_class, const char *message);
diff --git a/lib/misc/lvm-file.h b/lib/misc/lvm-file.h
index c92f783..6128abd 100644
--- a/lib/misc/lvm-file.h
+++ b/lib/misc/lvm-file.h
@@ -16,6 +16,12 @@
#ifndef _LVM_FILE_H
#define _LVM_FILE_H
+struct custom_fds {
+ int out;
+ int err;
+ int report;
+};
+
/*
* Create a temporary filename, and opens a descriptor to the file.
*/
diff --git a/man/lvm.8.in b/man/lvm.8.in
index 0215783..76d05fd 100644
--- a/man/lvm.8.in
+++ b/man/lvm.8.in
@@ -748,6 +748,15 @@ All tools return a status code of zero on success or non-zero on failure.
Directory containing \fI.lvm_history\fP if the internal readline
shell is invoked.
.TP
+.B LVM_OUT_FD
+File descriptor to use for common output from LVM commands.
+.TP
+.B LVM_ERR_FD
+File descriptor to use for error output from LVM commands.
+.TP
+.B LVM_REPORT_FD
+File descriptor to use for report output from LVM commands.
+.TP
.B LVM_COMMAND_PROFILE
Name of default command profile to use for LVM commands. This profile
is overriden by direct use of \fB\-\-commandprofile\fP command line option.
diff --git a/tools/lvmcmdline.c b/tools/lvmcmdline.c
index 3c3498a..629fb14 100644
--- a/tools/lvmcmdline.c
+++ b/tools/lvmcmdline.c
@@ -1838,6 +1838,39 @@ static int _check_standard_fds(void)
return 1;
}
+#define LVM_OUT_FD_ENV_VAR_NAME "LVM_OUT_FD"
+#define LVM_ERR_FD_ENV_VAR_NAME "LVM_ERR_FD"
+#define LVM_REPORT_FD_ENV_VAR_NAME "LVM_REPORT_FD"
+
+static int _do_get_custom_fd(const char *env_var_name, int *fd)
+{
+ const char *str;
+ char *endptr;
+ int tmp_fd;
+
+ *fd = -1;
+
+ if (!(str = getenv(env_var_name)))
+ return 1;
+
+ errno = 0;
+ tmp_fd = strtol(str, &endptr, 10);
+ if (errno || *endptr || (tmp_fd < 0) || (tmp_fd > INT_MAX)) {
+ log_error("%s: invalid file descriptor.", env_var_name);
+ return 0;
+ }
+
+ *fd = tmp_fd;
+ return 1;
+}
+
+static int _get_custom_fds(struct custom_fds *custom_fds)
+{
+ return _do_get_custom_fd(LVM_OUT_FD_ENV_VAR_NAME, &custom_fds->out) &&
+ _do_get_custom_fd(LVM_ERR_FD_ENV_VAR_NAME, &custom_fds->err) &&
+ _do_get_custom_fd(LVM_REPORT_FD_ENV_VAR_NAME, &custom_fds->report);
+}
+
static const char *_get_cmdline(pid_t pid)
{
static char _proc_cmdline[32];
@@ -1905,7 +1938,7 @@ static void _close_descriptor(int fd, unsigned suppress_warnings,
fprintf(stderr, " Parent PID %" PRIpid_t ": %s\n", ppid, parent_cmdline);
}
-static int _close_stray_fds(const char *command)
+static int _close_stray_fds(const char *command, struct custom_fds *custom_fds)
{
#ifndef VALGRIND_POOL
struct rlimit rlim;
@@ -1939,17 +1972,27 @@ static int _close_stray_fds(const char *command)
return 1;
}
- for (fd = 3; fd < (int)rlim.rlim_cur; fd++)
- _close_descriptor(fd, suppress_warnings, command, ppid,
- parent_cmdline);
+ for (fd = 3; fd < (int)rlim.rlim_cur; fd++) {
+ if ((fd != custom_fds->out) &&
+ (fd != custom_fds->err) &&
+ (fd != custom_fds->report)) {
+ _close_descriptor(fd, suppress_warnings, command, ppid,
+ parent_cmdline);
+ }
+ }
return 1;
}
while ((dirent = readdir(d))) {
fd = atoi(dirent->d_name);
- if (fd > 2 && fd != dirfd(d))
+ if ((fd > 2) &&
+ (fd != dirfd(d)) &&
+ (fd != custom_fds->out) &&
+ (fd != custom_fds->err) &&
+ (fd != custom_fds->report)) {
_close_descriptor(fd, suppress_warnings,
command, ppid, parent_cmdline);
+ }
}
if (closedir(d))
@@ -2111,6 +2154,7 @@ int lvm2_main(int argc, char **argv)
{
const char *base;
int ret, alias = 0;
+ struct custom_fds custom_fds;
struct cmd_context *cmd;
if (!argv)
@@ -2124,7 +2168,13 @@ int lvm2_main(int argc, char **argv)
if (!_check_standard_fds())
return -1;
- if (!_close_stray_fds(base))
+ if (!_get_custom_fds(&custom_fds))
+ return -1;
+
+ if (!_close_stray_fds(base, &custom_fds))
+ return -1;
+
+ if (!init_custom_log_streams(&custom_fds))
return -1;
if (is_static() && strcmp(base, "lvm.static") &&
More information about the lvm-devel
mailing list