c8h4/postgresql
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Don't use BLCKSZ for the physical length of the pg_control file, but

Browse source 
instead a dedicated symbol.  This probably makes no functional difference
for likely values of BLCKSZ, but it makes the intent clearer.
Simon Riggs, minor editorialization by Tom Lane.
This commit is contained in:
Tom Lane 2006-04-04 22:39:59 +00:00
parent 147d4bf3e5
commit e6140d9052
3 changed files with 34 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
src/backend/access/transam/xlog.c
View file

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.232 2006/04/03 23:35:03 tgl Exp $ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.233 2006/04/04 22:39:59 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -3391,7 +3391,7 @@ static void
WriteControlFile(void) WriteControlFile(void)
{ {
int fd; int fd;
char buffer[BLCKSZ]; /* need not be aligned */ char buffer[PG_CONTROL_SIZE]; /* need not be aligned */
char *localeptr; char *localeptr;
/* /*
@ -3437,17 +3437,16 @@ WriteControlFile(void)
FIN_CRC32(ControlFile->crc); FIN_CRC32(ControlFile->crc);
/* /*
* We write out BLCKSZ bytes into pg_control, zero-padding the excess over * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
* sizeof(ControlFileData). This reduces the odds of premature-EOF errors * excess over sizeof(ControlFileData). This reduces the odds of
* when reading pg_control. We'll still fail when we check the contents * premature-EOF errors when reading pg_control. We'll still fail when we
* of the file, but hopefully with a more specific error than "couldn't * check the contents of the file, but hopefully with a more specific
* read pg_control". * error than "couldn't read pg_control".
*/ */
if (sizeof(ControlFileData) > BLCKSZ) if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
ereport(PANIC, elog(PANIC, "sizeof(ControlFileData) is larger than PG_CONTROL_SIZE; fix either one");
(errmsg("sizeof(ControlFileData) is larger than BLCKSZ; fix either one")));
memset(buffer, 0, BLCKSZ); memset(buffer, 0, PG_CONTROL_SIZE);
memcpy(buffer, ControlFile, sizeof(ControlFileData)); memcpy(buffer, ControlFile, sizeof(ControlFileData));
fd = BasicOpenFile(XLOG_CONTROL_FILE, fd = BasicOpenFile(XLOG_CONTROL_FILE,
@ -3460,7 +3459,7 @@ WriteControlFile(void)
XLOG_CONTROL_FILE))); XLOG_CONTROL_FILE)));
errno = 0; errno = 0;
if (write(fd, buffer, BLCKSZ) != BLCKSZ) if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
{ {
/* if write didn't set errno, assume problem is no disk space */ /* if write didn't set errno, assume problem is no disk space */
if (errno == 0) if (errno == 0)

26
src/bin/pg_resetxlog/pg_resetxlog.c
View file

@ -23,7 +23,7 @@
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.41 2006/04/03 23:35:04 tgl Exp $ * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.42 2006/04/04 22:39:59 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -365,9 +365,9 @@ ReadControlFile(void)
} }
/* Use malloc to ensure we have a maxaligned buffer */ /* Use malloc to ensure we have a maxaligned buffer */
buffer = (char *) malloc(BLCKSZ); buffer = (char *) malloc(PG_CONTROL_SIZE);
len = read(fd, buffer, BLCKSZ); len = read(fd, buffer, PG_CONTROL_SIZE);
if (len < 0) if (len < 0)
{ {
fprintf(stderr, _("%s: could not read file \"%s\": %s\n"), fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
@ -546,7 +546,7 @@ static void
RewriteControlFile(void) RewriteControlFile(void)
{ {
int fd; int fd;
char buffer[BLCKSZ]; /* need not be aligned */ char buffer[PG_CONTROL_SIZE]; /* need not be aligned */
/* /*
* Adjust fields as needed to force an empty XLOG starting at the next * Adjust fields as needed to force an empty XLOG starting at the next
@ -587,21 +587,21 @@ RewriteControlFile(void)
FIN_CRC32(ControlFile.crc); FIN_CRC32(ControlFile.crc);
/* /*
* We write out BLCKSZ bytes into pg_control, zero-padding the excess over * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
* sizeof(ControlFileData). This reduces the odds of premature-EOF errors * excess over sizeof(ControlFileData). This reduces the odds of
* when reading pg_control. We'll still fail when we check the contents * premature-EOF errors when reading pg_control. We'll still fail when we
* of the file, but hopefully with a more specific error than "couldn't * check the contents of the file, but hopefully with a more specific
* read pg_control". * error than "couldn't read pg_control".
*/ */
if (sizeof(ControlFileData) > BLCKSZ) if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
{ {
fprintf(stderr, fprintf(stderr,
_("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"), _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
progname); progname);
exit(1); exit(1);
} }
memset(buffer, 0, BLCKSZ); memset(buffer, 0, PG_CONTROL_SIZE);
memcpy(buffer, &ControlFile, sizeof(ControlFileData)); memcpy(buffer, &ControlFile, sizeof(ControlFileData));
unlink(XLOG_CONTROL_FILE); unlink(XLOG_CONTROL_FILE);
@ -617,7 +617,7 @@ RewriteControlFile(void)
} }
errno = 0; errno = 0;
if (write(fd, buffer, BLCKSZ) != BLCKSZ) if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
{ {
/* if write didn't set errno, assume problem is no disk space */ /* if write didn't set errno, assume problem is no disk space */
if (errno == 0) if (errno == 0)

11
src/include/catalog/pg_control.h
View file

@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $PostgreSQL: pgsql/src/include/catalog/pg_control.h,v 1.28 2006/04/03 23:35:05 tgl Exp $ * $PostgreSQL: pgsql/src/include/catalog/pg_control.h,v 1.29 2006/04/04 22:39:59 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -147,4 +147,13 @@ typedef struct ControlFileData
pg_crc32 crc; pg_crc32 crc;
} ControlFileData; } ControlFileData;
/*
* Physical size of the pg_control file. Note that this is considerably
* bigger than the actually used size (ie, sizeof(ControlFileData)).
* The idea is to keep the physical size constant independent of format
* changes, so that ReadControlFile will deliver a suitable wrong-version
* message instead of a read error if it's looking at an incompatible file.
*/
#define PG_CONTROL_SIZE 8192
#endif /* PG_CONTROL_H */ #endif /* PG_CONTROL_H */