XLog encryption prototype

pg.patch

@@ -0,0 +1,155 @@
+diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
+index 8b0710abe6..a0cac5e0f5 100644
+--- a/src/backend/access/transam/xlog.c
++++ b/src/backend/access/transam/xlog.c
+@@ -62,6 +62,7 @@
+ #include "access/xlogprefetcher.h"
+ #include "access/xlogreader.h"
+ #include "access/xlogrecovery.h"
++#include "access/xlog_smgr.h"
+ #include "access/xlogutils.h"
+ #include "backup/basebackup.h"
+ #include "catalog/catversion.h"
+@@ -2193,8 +2194,9 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
+ 				else
+ 					INSTR_TIME_SET_ZERO(start);
+
++
+ 				pgstat_report_wait_start(WAIT_EVENT_WAL_WRITE);
+-				written = pg_pwrite(openLogFile, from, nleft, startoffset);
++				written = xlog_smgr->seg_write(openLogFile, from, nleft, startoffset);
+ 				pgstat_report_wait_end();
+
+ 				/*
+diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
+index c9f9f6e98f..b7a8ab0b79 100644
+--- a/src/backend/access/transam/xlogreader.c
++++ b/src/backend/access/transam/xlogreader.c
+@@ -29,6 +29,7 @@
+ #include "access/xlog_internal.h"
+ #include "access/xlogreader.h"
+ #include "access/xlogrecord.h"
++#include "access/xlog_smgr.h"
+ #include "catalog/pg_control.h"
+ #include "common/pg_lzcompress.h"
+ #include "replication/origin.h"
+@@ -65,6 +66,21 @@ static void WALOpenSegmentInit(WALOpenSegment *seg, WALSegmentContext *segcxt,
+  */
+ #define DEFAULT_DECODE_BUFFER_SIZE (64 * 1024)
+
++/* 
++ * XLog storage manager
++ *
++ * TODO: should be in xlog.c or new xlog_smgr.c ?
++ * Now it's here because pg_rewind and other tools compile only
++ * w/ xlogreader.c  
++ */
++XLogSmgr *xlog_smgr = &xlog_smgr_standard;
++
++void 
++SetXLogSmgr(XLogSmgr *xlsmgr)
++{
++	xlog_smgr = xlsmgr;
++}
++
+ /*
+  * Construct a string in state->errormsg_buf explaining what's wrong with
+  * the current record being read.
+@@ -1543,7 +1559,7 @@ WALRead(XLogReaderState *state,
+
+ 		/* Reset errno first; eases reporting non-errno-affecting errors */
+ 		errno = 0;
+-		readbytes = pg_pread(state->seg.ws_file, p, segbytes, (off_t) startoff);
++		readbytes = xlog_smgr->seg_read(state->seg.ws_file, p, segbytes, (off_t) startoff);
+
+ #ifndef FRONTEND
+ 		pgstat_report_wait_end();
+diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
+index becc2bda62..3d5010554f 100644
+--- a/src/backend/access/transam/xlogrecovery.c
++++ b/src/backend/access/transam/xlogrecovery.c
+@@ -39,6 +39,7 @@
+ #include "access/xlogprefetcher.h"
+ #include "access/xlogreader.h"
+ #include "access/xlogrecovery.h"
++#include "access/xlog_smgr.h"
+ #include "access/xlogutils.h"
+ #include "backup/basebackup.h"
+ #include "catalog/pg_control.h"
+@@ -3313,7 +3314,7 @@ retry:
+ 	readOff = targetPageOff;
+
+ 	pgstat_report_wait_start(WAIT_EVENT_WAL_READ);
+-	r = pg_pread(readFile, readBuf, XLOG_BLCKSZ, (off_t) readOff);
++	r = xlog_smgr->seg_read(readFile, readBuf, XLOG_BLCKSZ, (off_t) readOff);
+ 	if (r != XLOG_BLCKSZ)
+ 	{
+ 		char		fname[MAXFNAMELEN];
+diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
+index feff709435..f78eef1266 100644
+--- a/src/backend/replication/walreceiver.c
++++ b/src/backend/replication/walreceiver.c
+@@ -57,6 +57,7 @@
+ #include "access/xlog_internal.h"
+ #include "access/xlogarchive.h"
+ #include "access/xlogrecovery.h"
++#include "access/xlog_smgr.h"
+ #include "catalog/pg_authid.h"
+ #include "catalog/pg_type.h"
+ #include "common/ip.h"
+@@ -936,7 +937,7 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr, TimeLineID tli)
+ 		/* OK to write the logs */
+ 		errno = 0;
+
+-		byteswritten = pg_pwrite(recvFile, buf, segbytes, (off_t) startoff);
++		byteswritten = xlog_smgr->seg_write(recvFile, buf, segbytes, (off_t) startoff);
+ 		if (byteswritten <= 0)
+ 		{
+ 			char		xlogfname[MAXFNAMELEN];
+diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
+index b0fd338a00..e42b131b36 100644
+--- a/src/include/access/xlog_internal.h
++++ b/src/include/access/xlog_internal.h
+@@ -78,8 +78,10 @@ typedef XLogLongPageHeaderData *XLogLongPageHeader;
+ #define XLP_BKP_REMOVABLE			0x0004
+ /* Replaces a missing contrecord; see CreateOverwriteContrecordRecord */
+ #define XLP_FIRST_IS_OVERWRITE_CONTRECORD 0x0008
++/* The page is encrypted */
++#define XLP_ENCRYPTED 0x0010
+ /* All defined flag bits in xlp_info (used for validity checking of header) */
+-#define XLP_ALL_FLAGS				0x000F
++#define XLP_ALL_FLAGS				0x001F
+
+ #define XLogPageHeaderSize(hdr)		\
+ 	(((hdr)->xlp_info & XLP_LONG_HEADER) ? SizeOfXLogLongPHD : SizeOfXLogShortPHD)
+diff --git a/src/include/access/xlog_smgr.h b/src/include/access/xlog_smgr.h
+new file mode 100644
+index 0000000000..e79e290ddc
+--- /dev/null
++++ b/src/include/access/xlog_smgr.h
+@@ -0,0 +1,24 @@
++#ifndef XLOG_SMGR_H
++#define XLOG_SMGR_H
++
++#include "postgres.h"
++
++#include <unistd.h>
++
++/* XLog storage manager interface */
++typedef struct XLogSmgr {
++	ssize_t (*seg_read) (int fd, void *buf, size_t count, off_t offset);
++
++ 	ssize_t (*seg_write) (int fd, const void *buf, size_t count, off_t offset);
++} XLogSmgr;
++
++/* Default (standard) XLog storage manager */
++static const XLogSmgr xlog_smgr_standard = {
++	.seg_read = pg_pread,
++	.seg_write = pg_pwrite,
++};
++
++extern XLogSmgr *xlog_smgr;
++extern void SetXLogSmgr(XLogSmgr *xlsmgr);
++
++#endif							/* XLOG_SMGR_H */
+\ No newline at end of file