Back-patch log_newpage_range().

Back-patch a subset of commit 9155580fd5fc2a0cbb23376dfca7cd21f59c2c7b
to v11, v10, 9.6, and 9.5.  Include the latest repairs to this function.
Use a new XLOG_FPI_MULTI value instead of reusing XLOG_FPI.  That way,
if an older server reads WAL from this function, that server will PANIC
instead of applying just one page of the record.  The next commit adds a
call to this function.

Discussion: https://postgr.es/m/20200304.162919.898938381201316571.horikyota.ntt@gmail.com

diff --git a/src/backend/access/rmgrdesc/xlogdesc.c b/src/backend/access/rmgrdesc/xlogdesc.c
index f72f0760173b1411332b9e9f9b1d947042617cfa..563fae5ebfac3345e3f708d690c9cefc66fc9400 100644 (file)
--- a/src/backend/access/rmgrdesc/xlogdesc.c
+++ b/src/backend/access/rmgrdesc/xlogdesc.c
@@ -78,7 +78,8 @@ xlog_desc(StringInfo buf, XLogReaderState *record)
 
                appendStringInfoString(buf, xlrec->rp_name);
        }
-       else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)
+       else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
+                        info == XLOG_FPI_MULTI)
        {
                /* no further information to print */
        }
@@ -182,6 +183,9 @@ xlog_identify(uint8 info)
                case XLOG_FPI_FOR_HINT:
                        id = "FPI_FOR_HINT";
                        break;
+               case XLOG_FPI_MULTI:
+                       id = "FPI_MULTI";
+                       break;
        }
 
        return id;

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index f4b059aa2e8711b7cea96cd09f90a8d6670ca073..ec66b99b325f818b7c6ad795f1658874c938c532 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -9721,7 +9721,7 @@ xlog_redo(XLogReaderState *record)
 
        /* in XLOG rmgr, backup blocks are only used by XLOG_FPI records */
        Assert(info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
-                  !XLogRecHasAnyBlockRefs(record));
+                  info == XLOG_FPI_MULTI || !XLogRecHasAnyBlockRefs(record));
 
        if (info == XLOG_NEXTOID)
        {
@@ -9924,14 +9924,16 @@ xlog_redo(XLogReaderState *record)
        {
                /* nothing to do here */
        }
-       else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT)
+       else if (info == XLOG_FPI || info == XLOG_FPI_FOR_HINT ||
+                        info == XLOG_FPI_MULTI)
        {
-               Buffer          buffer;
+               uint8           block_id;
 
                /*
                 * Full-page image (FPI) records contain nothing else but a backup
-                * block. The block reference must include a full-page image -
-                * otherwise there would be no point in this record.
+                * block (or multiple backup blocks). Every block reference must
+                * include a full-page image - otherwise there would be no point in
+                * this record.
                 *
                 * No recovery conflicts are generated by these generic records - if a
                 * resource manager needs to generate conflicts, it has to define a
@@ -9943,9 +9945,14 @@ xlog_redo(XLogReaderState *record)
                 * XLOG_FPI and XLOG_FPI_FOR_HINT records, they use a different info
                 * code just to distinguish them for statistics purposes.
                 */
-               if (XLogReadBufferForRedo(record, 0, &buffer) != BLK_RESTORED)
-                       elog(ERROR, "unexpected XLogReadBufferForRedo result when restoring backup block");
-               UnlockReleaseBuffer(buffer);
+               for (block_id = 0; block_id <= record->max_block_id; block_id++)
+               {
+                       Buffer          buffer;
+
+                       if (XLogReadBufferForRedo(record, block_id, &buffer) != BLK_RESTORED)
+                               elog(ERROR, "unexpected XLogReadBufferForRedo result when restoring backup block");
+                       UnlockReleaseBuffer(buffer);
+               }
        }
        else if (info == XLOG_BACKUP_END)
        {

diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 1f86c907598be35a4534006e3c4f3e6086b5d9cc..579d8de775959157a99c75097b18d0a2925953c1 100644 (file)
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -1021,6 +1021,94 @@ log_newpage_buffer(Buffer buffer, bool page_std)
        return log_newpage(&rnode, forkNum, blkno, page, page_std);
 }
 
+/*
+ * WAL-log a range of blocks in a relation.
+ *
+ * An image of all pages with block numbers 'startblk' <= X < 'endblk' is
+ * written to the WAL. If the range is large, this is done in multiple WAL
+ * records.
+ *
+ * If all page follows the standard page layout, with a PageHeader and unused
+ * space between pd_lower and pd_upper, set 'page_std' to true. That allows
+ * the unused space to be left out from the WAL records, making them smaller.
+ *
+ * NOTE: This function acquires exclusive-locks on the pages. Typically, this
+ * is used on a newly-built relation, and the caller is holding a
+ * AccessExclusiveLock on it, so no other backend can be accessing it at the
+ * same time. If that's not the case, you must ensure that this does not
+ * cause a deadlock through some other means.
+ */
+void
+log_newpage_range(Relation rel, ForkNumber forkNum,
+                                 BlockNumber startblk, BlockNumber endblk,
+                                 bool page_std)
+{
+       int                     flags;
+       BlockNumber blkno;
+
+       flags = REGBUF_FORCE_IMAGE;
+       if (page_std)
+               flags |= REGBUF_STANDARD;
+
+       /*
+        * Iterate over all the pages in the range. They are collected into
+        * batches of XLR_MAX_BLOCK_ID pages, and a single WAL-record is written
+        * for each batch.
+        */
+       XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
+
+       blkno = startblk;
+       while (blkno < endblk)
+       {
+               Buffer          bufpack[XLR_MAX_BLOCK_ID];
+               XLogRecPtr      recptr;
+               int                     nbufs;
+               int                     i;
+
+               CHECK_FOR_INTERRUPTS();
+
+               /* Collect a batch of blocks. */
+               nbufs = 0;
+               while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
+               {
+                       Buffer          buf = ReadBufferExtended(rel, forkNum, blkno,
+                                                                                                RBM_NORMAL, NULL);
+
+                       LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+
+                       /*
+                        * Completely empty pages are not WAL-logged. Writing a WAL record
+                        * would change the LSN, and we don't want that. We want the page
+                        * to stay empty.
+                        */
+                       if (!PageIsNew(BufferGetPage(buf)))
+                               bufpack[nbufs++] = buf;
+                       else
+                               UnlockReleaseBuffer(buf);
+                       blkno++;
+               }
+
+               /* Write WAL record for this batch. */
+               XLogBeginInsert();
+
+               START_CRIT_SECTION();
+               for (i = 0; i < nbufs; i++)
+               {
+                       XLogRegisterBuffer(i, bufpack[i], flags);
+                       MarkBufferDirty(bufpack[i]);
+               }
+
+               recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_MULTI);
+
+               for (i = 0; i < nbufs; i++)
+               {
+                       PageSetLSN(BufferGetPage(bufpack[i]), recptr);
+                       UnlockReleaseBuffer(bufpack[i]);
+               }
+               END_CRIT_SECTION();
+       }
+}
+
 /*
  * Allocate working buffers needed for WAL record construction.
  */

diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c
index 8274024b6c98987c9a9668e803f040805c1123b8..d7a6f5d468722c119aa08e4024cbf141e5626c27 100644 (file)
--- a/src/backend/replication/logical/decode.c
+++ b/src/backend/replication/logical/decode.c
@@ -195,6 +195,7 @@ DecodeXLogOp(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
                case XLOG_FPW_CHANGE:
                case XLOG_FPI_FOR_HINT:
                case XLOG_FPI:
+               case XLOG_FPI_MULTI:
                        break;
                default:
                        elog(ERROR, "unexpected RM_XLOG_ID record type: %u", info);

diff --git a/src/include/access/xloginsert.h b/src/include/access/xloginsert.h
index 174c88677f5d88ec29d7a3d9ef7fd7de492ffb79..09bf94630a46ee1d0fe4de48272afed1f61a07b3 100644 (file)
--- a/src/include/access/xloginsert.h
+++ b/src/include/access/xloginsert.h
@@ -16,6 +16,7 @@
 #include "storage/block.h"
 #include "storage/buf.h"
 #include "storage/relfilenode.h"
+#include "utils/relcache.h"
 
 /*
  * The minimum size of the WAL construction working area. If you need to
@@ -54,6 +55,8 @@ extern bool XLogCheckBufferNeedsBackup(Buffer buffer);
 extern XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum,
                        BlockNumber blk, char *page, bool page_std);
 extern XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std);
+extern void log_newpage_range(Relation rel, ForkNumber forkNum,
+                                 BlockNumber startblk, BlockNumber endblk, bool page_std);
 extern XLogRecPtr XLogSaveBufferForHint(Buffer buffer, bool buffer_std);
 
 extern void InitXLogInsert(void);

diff --git a/src/include/catalog/pg_control.h b/src/include/catalog/pg_control.h
index 1ec03caf5fbb8a47bba0ef0e70c96f5aa4387309..77b7a5e5299d7b102cf0408bec08c3cea3439741 100644 (file)
--- a/src/include/catalog/pg_control.h
+++ b/src/include/catalog/pg_control.h
@@ -76,6 +76,7 @@ typedef struct CheckPoint
 #define XLOG_END_OF_RECOVERY                   0x90
 #define XLOG_FPI_FOR_HINT                              0xA0
 #define XLOG_FPI                                               0xB0
+#define XLOG_FPI_MULTI                                 0xC0
 
 
 /*