postgresql/contrib/pg_xlogdump/pg_xlogdump.c
Bruce Momjian 7e04792a1c Update copyright for 2014
Update all files in head, and files COPYRIGHT and legal.sgml in all back
branches.
2014-01-07 16:05:30 -05:00

712 lines
17 KiB
C

/*-------------------------------------------------------------------------
*
* pg_xlogdump.c - decode and display WAL
*
* Copyright (c) 2013-2014, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pg_xlogdump/pg_xlogdump.c
*-------------------------------------------------------------------------
*/
#define FRONTEND 1
#include "postgres.h"
#include <dirent.h>
#include <unistd.h>
#include "access/xlog.h"
#include "access/xlogreader.h"
#include "access/transam.h"
#include "common/fe_memutils.h"
#include "common/relpath.h"
#include "getopt_long.h"
#include "rmgrdesc.h"
static const char *progname;
typedef struct XLogDumpPrivate
{
TimeLineID timeline;
char *inpath;
XLogRecPtr startptr;
XLogRecPtr endptr;
} XLogDumpPrivate;
typedef struct XLogDumpConfig
{
/* display options */
bool bkp_details;
int stop_after_records;
int already_displayed_records;
/* filter options */
int filter_by_rmgr;
TransactionId filter_by_xid;
bool filter_by_xid_enabled;
} XLogDumpConfig;
static void
fatal_error(const char *fmt,...)
__attribute__((format(PG_PRINTF_ATTRIBUTE, 1, 2)));
/*
* Big red button to push when things go horribly wrong.
*/
static void
fatal_error(const char *fmt,...)
{
va_list args;
fflush(stdout);
fprintf(stderr, "%s: FATAL: ", progname);
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
fputc('\n', stderr);
exit(EXIT_FAILURE);
}
static void
print_rmgr_list(void)
{
int i;
for (i = 0; i <= RM_MAX_ID; i++)
{
printf("%s\n", RmgrDescTable[i].rm_name);
}
}
/*
* Check whether directory exists and whether we can open it. Keep errno set so
* that the caller can report errors somewhat more accurately.
*/
static bool
verify_directory(const char *directory)
{
DIR *dir = opendir(directory);
if (dir == NULL)
return false;
closedir(dir);
return true;
}
/*
* Split a pathname as dirname(1) and basename(1) would.
*
* XXX this probably doesn't do very well on Windows. We probably need to
* apply canonicalize_path(), at the very least.
*/
static void
split_path(const char *path, char **dir, char **fname)
{
char *sep;
/* split filepath into directory & filename */
sep = strrchr(path, '/');
/* directory path */
if (sep != NULL)
{
*dir = pg_strdup(path);
(*dir)[(sep - path) + 1] = '\0'; /* no strndup */
*fname = pg_strdup(sep + 1);
}
/* local directory */
else
{
*dir = NULL;
*fname = pg_strdup(path);
}
}
/*
* Try to find the file in several places:
* if directory == NULL:
* fname
* XLOGDIR / fname
* $PGDATA / XLOGDIR / fname
* else
* directory / fname
* directory / XLOGDIR / fname
*
* return a read only fd
*/
static int
fuzzy_open_file(const char *directory, const char *fname)
{
int fd = -1;
char fpath[MAXPGPATH];
if (directory == NULL)
{
const char *datadir;
/* fname */
fd = open(fname, O_RDONLY | PG_BINARY, 0);
if (fd < 0 && errno != ENOENT)
return -1;
else if (fd > 0)
return fd;
/* XLOGDIR / fname */
snprintf(fpath, MAXPGPATH, "%s/%s",
XLOGDIR, fname);
fd = open(fpath, O_RDONLY | PG_BINARY, 0);
if (fd < 0 && errno != ENOENT)
return -1;
else if (fd > 0)
return fd;
datadir = getenv("PGDATA");
/* $PGDATA / XLOGDIR / fname */
if (datadir != NULL)
{
snprintf(fpath, MAXPGPATH, "%s/%s/%s",
datadir, XLOGDIR, fname);
fd = open(fpath, O_RDONLY | PG_BINARY, 0);
if (fd < 0 && errno != ENOENT)
return -1;
else if (fd > 0)
return fd;
}
}
else
{
/* directory / fname */
snprintf(fpath, MAXPGPATH, "%s/%s",
directory, fname);
fd = open(fpath, O_RDONLY | PG_BINARY, 0);
if (fd < 0 && errno != ENOENT)
return -1;
else if (fd > 0)
return fd;
/* directory / XLOGDIR / fname */
snprintf(fpath, MAXPGPATH, "%s/%s/%s",
directory, XLOGDIR, fname);
fd = open(fpath, O_RDONLY | PG_BINARY, 0);
if (fd < 0 && errno != ENOENT)
return -1;
else if (fd > 0)
return fd;
}
return -1;
}
/*
* Read count bytes from a segment file in the specified directory, for the
* given timeline, containing the specified record pointer; store the data in
* the passed buffer.
*/
static void
XLogDumpXLogRead(const char *directory, TimeLineID timeline_id,
XLogRecPtr startptr, char *buf, Size count)
{
char *p;
XLogRecPtr recptr;
Size nbytes;
static int sendFile = -1;
static XLogSegNo sendSegNo = 0;
static uint32 sendOff = 0;
p = buf;
recptr = startptr;
nbytes = count;
while (nbytes > 0)
{
uint32 startoff;
int segbytes;
int readbytes;
startoff = recptr % XLogSegSize;
if (sendFile < 0 || !XLByteInSeg(recptr, sendSegNo))
{
char fname[MAXFNAMELEN];
/* Switch to another logfile segment */
if (sendFile >= 0)
close(sendFile);
XLByteToSeg(recptr, sendSegNo);
XLogFileName(fname, timeline_id, sendSegNo);
sendFile = fuzzy_open_file(directory, fname);
if (sendFile < 0)
fatal_error("could not find file \"%s\": %s",
fname, strerror(errno));
sendOff = 0;
}
/* Need to seek in the file? */
if (sendOff != startoff)
{
if (lseek(sendFile, (off_t) startoff, SEEK_SET) < 0)
{
int err = errno;
char fname[MAXPGPATH];
XLogFileName(fname, timeline_id, sendSegNo);
fatal_error("could not seek in log segment %s to offset %u: %s",
fname, startoff, strerror(err));
}
sendOff = startoff;
}
/* How many bytes are within this segment? */
if (nbytes > (XLogSegSize - startoff))
segbytes = XLogSegSize - startoff;
else
segbytes = nbytes;
readbytes = read(sendFile, p, segbytes);
if (readbytes <= 0)
{
int err = errno;
char fname[MAXPGPATH];
XLogFileName(fname, timeline_id, sendSegNo);
fatal_error("could not read from log segment %s, offset %d, length %d: %s",
fname, sendOff, segbytes, strerror(err));
}
/* Update state for read */
recptr += readbytes;
sendOff += readbytes;
nbytes -= readbytes;
p += readbytes;
}
}
/*
* XLogReader read_page callback
*/
static int
XLogDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen,
XLogRecPtr targetPtr, char *readBuff, TimeLineID *curFileTLI)
{
XLogDumpPrivate *private = state->private_data;
int count = XLOG_BLCKSZ;
if (private->endptr != InvalidXLogRecPtr)
{
if (targetPagePtr + XLOG_BLCKSZ <= private->endptr)
count = XLOG_BLCKSZ;
else if (targetPagePtr + reqLen <= private->endptr)
count = private->endptr - targetPagePtr;
else
return -1;
}
XLogDumpXLogRead(private->inpath, private->timeline, targetPagePtr,
readBuff, count);
return count;
}
/*
* Print a record to stdout
*/
static void
XLogDumpDisplayRecord(XLogDumpConfig *config, XLogRecPtr ReadRecPtr, XLogRecord *record)
{
const RmgrDescData *desc = &RmgrDescTable[record->xl_rmid];
if (config->filter_by_rmgr != -1 &&
config->filter_by_rmgr != record->xl_rmid)
return;
if (config->filter_by_xid_enabled &&
config->filter_by_xid != record->xl_xid)
return;
config->already_displayed_records++;
printf("rmgr: %-11s len (rec/tot): %6u/%6u, tx: %10u, lsn: %X/%08X, prev %X/%08X, bkp: %u%u%u%u, desc: ",
desc->rm_name,
record->xl_len, record->xl_tot_len,
record->xl_xid,
(uint32) (ReadRecPtr >> 32), (uint32) ReadRecPtr,
(uint32) (record->xl_prev >> 32), (uint32) record->xl_prev,
!!(XLR_BKP_BLOCK(0) & record->xl_info),
!!(XLR_BKP_BLOCK(1) & record->xl_info),
!!(XLR_BKP_BLOCK(2) & record->xl_info),
!!(XLR_BKP_BLOCK(3) & record->xl_info));
/* the desc routine will printf the description directly to stdout */
desc->rm_desc(NULL, record->xl_info, XLogRecGetData(record));
putchar('\n');
if (config->bkp_details)
{
int bkpnum;
char *blk = (char *) XLogRecGetData(record) + record->xl_len;
for (bkpnum = 0; bkpnum < XLR_MAX_BKP_BLOCKS; bkpnum++)
{
BkpBlock bkpb;
if (!(XLR_BKP_BLOCK(bkpnum) & record->xl_info))
continue;
memcpy(&bkpb, blk, sizeof(BkpBlock));
blk += sizeof(BkpBlock);
blk += BLCKSZ - bkpb.hole_length;
printf("\tbackup bkp #%u; rel %u/%u/%u; fork: %s; block: %u; hole: offset: %u, length: %u\n",
bkpnum,
bkpb.node.spcNode, bkpb.node.dbNode, bkpb.node.relNode,
forkNames[bkpb.fork],
bkpb.block, bkpb.hole_offset, bkpb.hole_length);
}
}
}
static void
usage(void)
{
printf("%s decodes and displays PostgreSQL transaction logs for debugging.\n\n",
progname);
printf("Usage:\n");
printf(" %s [OPTION]... [STARTSEG [ENDSEG]] \n", progname);
printf("\nOptions:\n");
printf(" -b, --bkp-details output detailed information about backup blocks\n");
printf(" -e, --end=RECPTR stop reading at log position RECPTR\n");
printf(" -n, --limit=N number of records to display\n");
printf(" -p, --path=PATH directory in which to find log segment files\n");
printf(" (default: ./pg_xlog)\n");
printf(" -r, --rmgr=RMGR only show records generated by resource manager RMGR\n");
printf(" use --rmgr=list to list valid resource manager names\n");
printf(" -s, --start=RECPTR start reading at log position RECPTR\n");
printf(" -t, --timeline=TLI timeline from which to read log records\n");
printf(" (default: 1 or the value used in STARTSEG)\n");
printf(" -V, --version output version information, then exit\n");
printf(" -x, --xid=XID only show records with TransactionId XID\n");
printf(" -?, --help show this help, then exit\n");
}
int
main(int argc, char **argv)
{
uint32 xlogid;
uint32 xrecoff;
XLogReaderState *xlogreader_state;
XLogDumpPrivate private;
XLogDumpConfig config;
XLogRecord *record;
XLogRecPtr first_record;
char *errormsg;
static struct option long_options[] = {
{"bkp-details", no_argument, NULL, 'b'},
{"end", required_argument, NULL, 'e'},
{"help", no_argument, NULL, '?'},
{"limit", required_argument, NULL, 'n'},
{"path", required_argument, NULL, 'p'},
{"rmgr", required_argument, NULL, 'r'},
{"start", required_argument, NULL, 's'},
{"timeline", required_argument, NULL, 't'},
{"xid", required_argument, NULL, 'x'},
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
int option;
int optindex = 0;
progname = get_progname(argv[0]);
memset(&private, 0, sizeof(XLogDumpPrivate));
memset(&config, 0, sizeof(XLogDumpConfig));
private.timeline = 1;
private.startptr = InvalidXLogRecPtr;
private.endptr = InvalidXLogRecPtr;
config.bkp_details = false;
config.stop_after_records = -1;
config.already_displayed_records = 0;
config.filter_by_rmgr = -1;
config.filter_by_xid = InvalidTransactionId;
config.filter_by_xid_enabled = false;
if (argc <= 1)
{
fprintf(stderr, "%s: no arguments specified\n", progname);
goto bad_argument;
}
while ((option = getopt_long(argc, argv, "be:?n:p:r:s:t:Vx:",
long_options, &optindex)) != -1)
{
switch (option)
{
case 'b':
config.bkp_details = true;
break;
case 'e':
if (sscanf(optarg, "%X/%X", &xlogid, &xrecoff) != 2)
{
fprintf(stderr, "%s: could not parse end log position \"%s\"\n",
progname, optarg);
goto bad_argument;
}
private.endptr = (uint64) xlogid << 32 | xrecoff;
break;
case '?':
usage();
exit(EXIT_SUCCESS);
break;
case 'n':
if (sscanf(optarg, "%d", &config.stop_after_records) != 1)
{
fprintf(stderr, "%s: could not parse limit \"%s\"\n",
progname, optarg);
goto bad_argument;
}
break;
case 'p':
private.inpath = pg_strdup(optarg);
break;
case 'r':
{
int i;
if (pg_strcasecmp(optarg, "list") == 0)
{
print_rmgr_list();
exit(EXIT_SUCCESS);
}
for (i = 0; i <= RM_MAX_ID; i++)
{
if (pg_strcasecmp(optarg, RmgrDescTable[i].rm_name) == 0)
{
config.filter_by_rmgr = i;
break;
}
}
if (config.filter_by_rmgr == -1)
{
fprintf(stderr, "%s: resource manager \"%s\" does not exist\n",
progname, optarg);
goto bad_argument;
}
}
break;
case 's':
if (sscanf(optarg, "%X/%X", &xlogid, &xrecoff) != 2)
{
fprintf(stderr, "%s: could not parse start log position \"%s\"\n",
progname, optarg);
goto bad_argument;
}
else
private.startptr = (uint64) xlogid << 32 | xrecoff;
break;
case 't':
if (sscanf(optarg, "%d", &private.timeline) != 1)
{
fprintf(stderr, "%s: could not parse timeline \"%s\"\n",
progname, optarg);
goto bad_argument;
}
break;
case 'V':
puts("pg_xlogdump (PostgreSQL) " PG_VERSION);
exit(EXIT_SUCCESS);
break;
case 'x':
if (sscanf(optarg, "%u", &config.filter_by_xid) != 1)
{
fprintf(stderr, "%s: could not parse \"%s\" as a valid xid\n",
progname, optarg);
goto bad_argument;
}
config.filter_by_xid_enabled = true;
break;
default:
goto bad_argument;
}
}
if ((optind + 2) < argc)
{
fprintf(stderr,
"%s: too many command-line arguments (first is \"%s\")\n",
progname, argv[optind + 2]);
goto bad_argument;
}
if (private.inpath != NULL)
{
/* validate path points to directory */
if (!verify_directory(private.inpath))
{
fprintf(stderr,
"%s: path \"%s\" cannot be opened: %s",
progname, private.inpath, strerror(errno));
goto bad_argument;
}
}
/* parse files as start/end boundaries, extract path if not specified */
if (optind < argc)
{
char *directory = NULL;
char *fname = NULL;
int fd;
XLogSegNo segno;
split_path(argv[optind], &directory, &fname);
if (private.inpath == NULL && directory != NULL)
{
private.inpath = directory;
if (!verify_directory(private.inpath))
fatal_error("cannot open directory \"%s\": %s",
private.inpath, strerror(errno));
}
fd = fuzzy_open_file(private.inpath, fname);
if (fd < 0)
fatal_error("could not open file \"%s\"", fname);
close(fd);
/* parse position from file */
XLogFromFileName(fname, &private.timeline, &segno);
if (XLogRecPtrIsInvalid(private.startptr))
XLogSegNoOffsetToRecPtr(segno, 0, private.startptr);
else if (!XLByteInSeg(private.startptr, segno))
{
fprintf(stderr,
"%s: start log position %X/%X is not inside file \"%s\"\n",
progname,
(uint32) (private.startptr >> 32),
(uint32) private.startptr,
fname);
goto bad_argument;
}
/* no second file specified, set end position */
if (!(optind + 1 < argc) && XLogRecPtrIsInvalid(private.endptr))
XLogSegNoOffsetToRecPtr(segno + 1, 0, private.endptr);
/* parse ENDSEG if passed */
if (optind + 1 < argc)
{
XLogSegNo endsegno;
/* ignore directory, already have that */
split_path(argv[optind + 1], &directory, &fname);
fd = fuzzy_open_file(private.inpath, fname);
if (fd < 0)
fatal_error("could not open file \"%s\"", fname);
close(fd);
/* parse position from file */
XLogFromFileName(fname, &private.timeline, &endsegno);
if (endsegno < segno)
fatal_error("ENDSEG %s is before STARTSEG %s",
argv[optind + 1], argv[optind]);
if (XLogRecPtrIsInvalid(private.endptr))
XLogSegNoOffsetToRecPtr(endsegno + 1, 0, private.endptr);
/* set segno to endsegno for check of --end */
segno = endsegno;
}
if (!XLByteInSeg(private.endptr, segno) &&
private.endptr != (segno + 1) * XLogSegSize)
{
fprintf(stderr,
"%s: end log position %X/%X is not inside file \"%s\"\n",
progname,
(uint32) (private.endptr >> 32),
(uint32) private.endptr,
argv[argc - 1]);
goto bad_argument;
}
}
/* we don't know what to print */
if (XLogRecPtrIsInvalid(private.startptr))
{
fprintf(stderr, "%s: no start log position given in range mode.\n", progname);
goto bad_argument;
}
/* done with argument parsing, do the actual work */
/* we have everything we need, start reading */
xlogreader_state = XLogReaderAllocate(XLogDumpReadPage, &private);
if (!xlogreader_state)
fatal_error("out of memory");
/* first find a valid recptr to start from */
first_record = XLogFindNextRecord(xlogreader_state, private.startptr);
if (first_record == InvalidXLogRecPtr)
fatal_error("could not find a valid record after %X/%X",
(uint32) (private.startptr >> 32),
(uint32) private.startptr);
/*
* Display a message that we're skipping data if `from` wasn't a pointer
* to the start of a record and also wasn't a pointer to the beginning of
* a segment (e.g. we were used in file mode).
*/
if (first_record != private.startptr && (private.startptr % XLogSegSize) != 0)
printf("first record is after %X/%X, at %X/%X, skipping over %u bytes\n",
(uint32) (private.startptr >> 32), (uint32) private.startptr,
(uint32) (first_record >> 32), (uint32) first_record,
(uint32) (first_record - private.startptr));
while ((record = XLogReadRecord(xlogreader_state, first_record, &errormsg)))
{
/* continue after the last record */
first_record = InvalidXLogRecPtr;
XLogDumpDisplayRecord(&config, xlogreader_state->ReadRecPtr, record);
/* check whether we printed enough */
if (config.stop_after_records > 0 &&
config.already_displayed_records >= config.stop_after_records)
break;
}
if (errormsg)
fatal_error("error in WAL record at %X/%X: %s\n",
(uint32) (xlogreader_state->ReadRecPtr >> 32),
(uint32) xlogreader_state->ReadRecPtr,
errormsg);
XLogReaderFree(xlogreader_state);
return EXIT_SUCCESS;
bad_argument:
fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
return EXIT_FAILURE;
}