MDEV-30397: MariaDB crash due to DB_FAIL reported for a corrupted page

buf_read_page_low(): Map the buf_page_t::read_complete() return
value DB_FAIL to DB_PAGE_CORRUPTED. The purpose of the DB_FAIL
return value is to avoid error log noise when read-ahead brings
in an unused page that is typically filled with NUL bytes.

If a synchronous read is bringing in a corrupted page where the
page frame does not contain the expected tablespace identifier and
page number, that must be treated as an attempt to read a corrupted
page. The correct error code for this is DB_PAGE_CORRUPTED.
The error code DB_FAIL is not handled by row_mysql_handle_errors().

This was missed in commit 0b47c126e3
(MDEV-13542).

storage/innobase/buf/buf0buf.cc

@@ -3449,8 +3449,7 @@ or decrypt/decompress just failed.
 @retval	DB_SUCCESS		if page has been read and is not corrupted
 @retval	DB_PAGE_CORRUPTED	if page based on checksum check is corrupted
 @retval	DB_DECRYPTION_FAILED	if page post encryption checksum matches but
-after decryption normal page checksum does not match.
-@retval	DB_TABLESPACE_DELETED	if accessed tablespace is not found */
+after decryption normal page checksum does not match. */
 static dberr_t buf_page_check_corrupt(buf_page_t *bpage,
                                       const fil_node_t &node)
 {
@@ -3507,7 +3506,8 @@ static dberr_t buf_page_check_corrupt(buf_page_t *bpage,
 @param node     data file
 @return whether the operation succeeded
 @retval DB_PAGE_CORRUPTED    if the checksum fails
-@retval DB_DECRYPTION_FAILED if the page cannot be decrypted */
+@retval DB_DECRYPTION_FAILED if the page cannot be decrypted
+@retval DB_FAIL              if the page contains the wrong ID */
 dberr_t buf_page_t::read_complete(const fil_node_t &node)
 {
   const page_id_t expected_id{id()};

storage/innobase/buf/buf0rea.cc

@@ -331,6 +331,9 @@ nothing_read:
 		/* The i/o was already completed in space->io() */
 		*err = bpage->read_complete(*fio.node);
 		space->release();
+		if (*err == DB_FAIL) {
+			*err = DB_PAGE_CORRUPTED;
+		}
 	}
 
 	return true;

storage/innobase/include/buf0buf.h

@@ -773,7 +773,8 @@ public:
   @param node     data file
   @return whether the operation succeeded
   @retval DB_PAGE_CORRUPTED    if the checksum fails
-  @retval DB_DECRYPTION_FAILED if the page cannot be decrypted */
+  @retval DB_DECRYPTION_FAILED if the page cannot be decrypted
+  @retval DB_FAIL              if the page contains the wrong ID */
   dberr_t read_complete(const fil_node_t &node);
 
   /** Note that a block is no longer dirty, while not removing