MDEV-27058: Move buf_page_t::slot to IORequest::slot

MDEV-23855 and MDEV-23399 already moved some transient data fields
from buffer pool page descriptors to IORequest, but the write buffer
of PAGE_COMPRESSED or ENCRYPTED tables was missed. Since is only needed
during asynchronous page write requests, it belongs to IORequest.

7 files changed, 52 insertions, 68 deletions

diff --git a/storage/innobase/buf/buf0dblwr.cc b/storage/innobase/buf/buf0dblwr.cc
index 447fba38323..b8371864e16 100644
--- a/storage/innobase/buf/buf0dblwr.cc
+++ b/storage/innobase/buf/buf0dblwr.cc
@@ -594,8 +594,8 @@ bool buf_dblwr_t::flush_buffered_writes(const ulint size)
     ut_d(buf_dblwr_check_page_lsn(*bpage, write_buf + len2));
   }
 #endif /* UNIV_DEBUG */
-  const IORequest request(nullptr, fil_system.sys_space->chain.start,
-                          IORequest::DBLWR_BATCH);
+  const IORequest request{nullptr, nullptr, fil_system.sys_space->chain.start,
+                          IORequest::DBLWR_BATCH};
   ut_a(fil_system.sys_space->acquire());
   if (multi_batch)
   {
@@ -614,6 +614,16 @@ bool buf_dblwr_t::flush_buffered_writes(const ulint size)
   return true;
 }
 
+static void *get_frame(const IORequest &request)
+{
+  if (request.slot)
+    return request.slot->out_buf;
+  const buf_page_t *bpage= request.bpage;
+  return bpage->zip.data
+    ? bpage->zip.data
+    : reinterpret_cast<const buf_block_t*>(bpage)->frame;
+}
+
 void buf_dblwr_t::flush_buffered_writes_completed(const IORequest &request)
 {
   ut_ad(this == &buf_dblwr);
@@ -651,9 +661,8 @@ void buf_dblwr_t::flush_buffered_writes_completed(const IORequest &request)
     buf_page_t* bpage= e.request.bpage;
     ut_ad(bpage->in_file());
 
-    /* We request frame here to get correct buffer in case of
-    encryption and/or page compression */
-    void *frame= buf_page_get_frame(bpage);
+    void *frame= get_frame(e.request);
+    ut_ad(frame);
 
     auto e_size= e.size;
 
@@ -732,13 +741,9 @@ void buf_dblwr_t::add_to_batch(const IORequest &request, size_t size)
 
   byte *p= active_slot->write_buf + srv_page_size * active_slot->first_free;
 
-  /* We request frame here to get correct buffer in case of
-  encryption and/or page compression */
-  void *frame= buf_page_get_frame(request.bpage);
-
   /* "frame" is at least 1024-byte aligned for ROW_FORMAT=COMPRESSED pages,
   and at least srv_page_size (4096-byte) for everything else. */
-  memcpy_aligned<UNIV_ZIP_SIZE_MIN>(p, frame, size);
+  memcpy_aligned<UNIV_ZIP_SIZE_MIN>(p, get_frame(request), size);
   /* fil_page_compress() for page_compressed guarantees 256-byte alignment */
   memset_aligned<256>(p + size, 0, srv_page_size - size);
   /* FIXME: Inform the compiler that "size" and "srv_page_size - size"
diff --git a/storage/innobase/buf/buf0flu.cc b/storage/innobase/buf/buf0flu.cc
index 725f18ec25f..2fd60a79602 100644
--- a/storage/innobase/buf/buf0flu.cc
+++ b/storage/innobase/buf/buf0flu.cc
@@ -353,11 +353,8 @@ void buf_page_write_complete(const IORequest &request)
     }
   }
 
-  if (bpage->slot)
-  {
-    bpage->slot->release();
-    bpage->slot= nullptr;
-  }
+  if (request.slot)
+    request.slot->release();
 
   if (UNIV_UNLIKELY(MONITOR_IS_ON(MONITOR_MODULE_BUF_PAGE)))
     buf_page_monitor(bpage, BUF_IO_WRITE);
@@ -622,10 +619,11 @@ a page is written to disk.
 @return page frame to be written to file
 (may be src_frame or an encrypted/compressed copy of it) */
 static byte *buf_page_encrypt(fil_space_t* space, buf_page_t* bpage, byte* s,
-                              size_t *size)
+                              buf_tmp_buffer_t **slot, size_t *size)
 {
   ut_ad(bpage->status != buf_page_t::FREED);
   ut_ad(space->id == bpage->id().space());
+  ut_ad(!*slot);
 
   ut_d(fil_page_type_validate(space, s));
   const uint32_t page_no= bpage->id().page_no();
@@ -681,31 +679,25 @@ static byte *buf_page_encrypt(fil_space_t* space, buf_page_t* bpage, byte* s,
 
   ut_ad(!bpage->zip_size() || !page_compressed);
   /* Find free slot from temporary memory array */
-  buf_tmp_buffer_t *slot= buf_pool.io_buf_reserve();
-  ut_a(slot);
-  slot->allocate();
-  slot->out_buf= NULL;
-  bpage->slot= slot;
+  *slot= buf_pool.io_buf_reserve();
+  ut_a(*slot);
+  (*slot)->allocate();
 
-  byte *d= slot->crypt_buf;
+  byte *d= (*slot)->crypt_buf;
 
   if (!page_compressed)
   {
 not_compressed:
-    byte *tmp= space->purpose == FIL_TYPE_TEMPORARY
+    d= space->purpose == FIL_TYPE_TEMPORARY
       ? buf_tmp_page_encrypt(page_no, s, d)
       : fil_space_encrypt(space, page_no, s, d);
-
-    slot->out_buf= d= tmp;
-
-    ut_d(fil_page_type_validate(space, tmp));
   }
   else
   {
     ut_ad(space->purpose != FIL_TYPE_TEMPORARY);
     /* First we compress the page content */
-    buf_tmp_reserve_compression_buf(slot);
-    byte *tmp= slot->comp_buf;
+    buf_tmp_reserve_compression_buf(*slot);
+    byte *tmp= (*slot)->comp_buf;
     ulint len= fil_page_compress(s, tmp, space->flags,
                                  fil_space_get_block_size(space, page_no),
                                  encrypted);
@@ -733,7 +725,7 @@ not_compressed:
     ut_d(fil_page_type_validate(space, tmp));
 
     if (encrypted)
-      tmp = fil_space_encrypt(space, page_no, tmp, d);
+      tmp= fil_space_encrypt(space, page_no, tmp, d);
 
     if (full_crc32)
     {
@@ -742,10 +734,11 @@ not_compressed:
       ut_ad(!buf_page_is_corrupted(true, tmp, space->flags));
     }
 
-    slot->out_buf= d= tmp;
+    d= tmp;
   }
 
   ut_d(fil_page_type_validate(space, d));
+  (*slot)->out_buf= d;
   return d;
 }
 
@@ -860,6 +853,7 @@ static bool buf_flush_page(buf_page_t *bpage, bool lru, fil_space_t *space)
     size_t orig_size;
 #endif
     IORequest::Type type= lru ? IORequest::WRITE_LRU : IORequest::WRITE_ASYNC;
+    buf_tmp_buffer_t *slot= nullptr;
 
     if (UNIV_UNLIKELY(!rw_lock)) /* ROW_FORMAT=COMPRESSED */
     {
@@ -870,7 +864,7 @@ static bool buf_flush_page(buf_page_t *bpage, bool lru, fil_space_t *space)
       orig_size= size;
 #endif
       buf_flush_update_zip_checksum(frame, size);
-      frame= buf_page_encrypt(space, bpage, frame, &size);
+      frame= buf_page_encrypt(space, bpage, frame, &slot, &size);
       ut_ad(size == bpage->zip_size());
     }
     else
@@ -886,14 +880,15 @@ static bool buf_flush_page(buf_page_t *bpage, bool lru, fil_space_t *space)
         /* innodb_checksum_algorithm=full_crc32 is not implemented for
         ROW_FORMAT=COMPRESSED pages. */
         ut_ad(!frame);
-        page= buf_page_encrypt(space, bpage, page, &size);
+        page= buf_page_encrypt(space, bpage, page, &slot, &size);
         buf_flush_init_for_writing(block, page, nullptr, true);
       }
       else
       {
         buf_flush_init_for_writing(block, page, frame ? &bpage->zip : nullptr,
                                    false);
-        page= buf_page_encrypt(space, bpage, frame ? frame : page, &size);
+        page= buf_page_encrypt(space, bpage, frame ? frame : page,
+                               &slot, &size);
       }
 
 #if defined HAVE_FALLOC_PUNCH_HOLE_AND_KEEP_SIZE || defined _WIN32
@@ -908,7 +903,7 @@ static bool buf_flush_page(buf_page_t *bpage, bool lru, fil_space_t *space)
         }
       }
 #endif
-      frame=page;
+      frame= page;
     }
 
     ut_ad(status == bpage->status);
@@ -925,11 +920,12 @@ static bool buf_flush_page(buf_page_t *bpage, bool lru, fil_space_t *space)
         if (lsn > log_sys.get_flushed_lsn())
           log_write_up_to(lsn, true);
       }
-      space->io(IORequest(type, bpage),
+      space->io(IORequest{type, bpage, slot},
                 bpage->physical_offset(), size, frame, bpage);
     }
     else
-      buf_dblwr.add_to_batch(IORequest(bpage, space->chain.start, type), size);
+      buf_dblwr.add_to_batch(IORequest{bpage, slot, space->chain.start, type},
+                             size);
   }
 
   /* Increment the I/O operation count used for selecting LRU policy. */
diff --git a/storage/innobase/fil/fil0fil.cc b/storage/innobase/fil/fil0fil.cc
index adb4bdef1c5..32bafb14684 100644
--- a/storage/innobase/fil/fil0fil.cc
+++ b/storage/innobase/fil/fil0fil.cc
@@ -2867,7 +2867,7 @@ fail:
 		goto release_sync_write;
 	} else {
 		/* Queue the aio request */
-		err = os_aio(IORequest(bpage, node, type.type),
+		err = os_aio(IORequest{bpage, type.slot, node, type.type},
 			     buf, offset, len);
 	}
 
diff --git a/storage/innobase/include/buf0buf.h b/storage/innobase/include/buf0buf.h
index ad06b17466d..fce5702c171 100644
--- a/storage/innobase/include/buf0buf.h
+++ b/storage/innobase/include/buf0buf.h
@@ -663,10 +663,6 @@ public:
 					state == BUF_BLOCK_ZIP_PAGE and
 					zip.data == NULL means an active
 					buf_pool.watch */
-
-	buf_tmp_buffer_t* slot;		/*!< Slot for temporary memory
-					used for encryption/compression
-					or NULL */
 #ifdef UNIV_DEBUG
   /** whether this->list is in buf_pool.zip_hash; protected by buf_pool.mutex */
   bool in_zip_hash;
@@ -755,7 +751,6 @@ public:
     freed_page_clock= 0;
     access_time= 0;
     oldest_modification_= 0;
-    slot= nullptr;
     ibuf_exist= false;
     status= NORMAL;
     ut_d(in_zip_hash= false);
diff --git a/storage/innobase/include/buf0buf.ic b/storage/innobase/include/buf0buf.ic
index 30fd0b2b1f9..bdca5b66392 100644
--- a/storage/innobase/include/buf0buf.ic
+++ b/storage/innobase/include/buf0buf.ic
@@ -227,25 +227,6 @@ buf_page_release_latch(
   }
 }
 
-/********************************************************************//**
-Get buf frame. */
-UNIV_INLINE
-void *
-buf_page_get_frame(
-/*===============*/
-	const buf_page_t*	bpage) /*!< in: buffer pool page */
-{
-	/* In encryption/compression buffer pool page may contain extra
-	buffer where result is stored. */
-	if (bpage->slot && bpage->slot->out_buf) {
-		return bpage->slot->out_buf;
-	} else if (bpage->zip.data) {
-		return bpage->zip.data;
-	} else {
-		return ((buf_block_t*) bpage)->frame;
-	}
-}
-
 /** Calculate aligned buffer pool size based on srv_buf_pool_chunk_unit,
 if needed.
 @param[in]	size	size in bytes
diff --git a/storage/innobase/include/os0file.h b/storage/innobase/include/os0file.h
index 7e190b340de..17680f9b3dc 100644
--- a/storage/innobase/include/os0file.h
+++ b/storage/innobase/include/os0file.h
@@ -51,6 +51,8 @@ extern bool	os_has_said_disk_full;
 /** File offset in bytes */
 typedef ib_uint64_t os_offset_t;
 
+class buf_tmp_buffer_t;
+
 #ifdef _WIN32
 
 /** We define always WIN_ASYNC_IO, and check at run-time whether
@@ -206,11 +208,13 @@ public:
     PUNCH_RANGE= WRITE_SYNC | 128,
   };
 
-  constexpr IORequest(buf_page_t *bpage, fil_node_t *node, Type type) :
-    bpage(bpage), node(node), type(type) {}
+  constexpr IORequest(buf_page_t *bpage, buf_tmp_buffer_t *slot,
+                      fil_node_t *node, Type type) :
+    bpage(bpage), slot(slot), node(node), type(type) {}
 
-  constexpr IORequest(Type type= READ_SYNC, buf_page_t *bpage= nullptr) :
-    bpage(bpage), type(type) {}
+  constexpr IORequest(Type type= READ_SYNC, buf_page_t *bpage= nullptr,
+                      buf_tmp_buffer_t *slot= nullptr) :
+    bpage(bpage), slot(slot), type(type) {}
 
   bool is_read() const { return (type & READ_SYNC) != 0; }
   bool is_write() const { return (type & WRITE_SYNC) != 0; }
@@ -237,7 +241,10 @@ private:
 
 public:
   /** Page to be written on write operation */
-  buf_page_t* const bpage= nullptr;
+  buf_page_t *const bpage= nullptr;
+
+  /** Memory to be used for encrypted or page_compressed pages */
+  buf_tmp_buffer_t *const slot= nullptr;
 
   /** File descriptor */
   fil_node_t *const node= nullptr;
diff --git a/tpool/tpool.h b/tpool/tpool.h
index 95e4205e601..8d14d637914 100644
--- a/tpool/tpool.h
+++ b/tpool/tpool.h
@@ -117,7 +117,7 @@ enum class aio_opcode
   AIO_PREAD,
   AIO_PWRITE
 };
-constexpr size_t MAX_AIO_USERDATA_LEN= 3 * sizeof(void*);
+constexpr size_t MAX_AIO_USERDATA_LEN= 4 * sizeof(void*);
 
 /** IO control block, includes parameters for the IO, and the callback*/