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Fixed table crash bug when updating row > 16M (Bug #2159)

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This commit is contained in:
monty@mysql.com 2004-01-15 21:39:56 +01:00
parent 8178bd4ec8
commit d4543818b0
4 changed files with 156 additions and 36 deletions
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134
myisam/mi_dynrec.c
View File

@ -14,7 +14,15 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Functions to handle space-packed-records and blobs */
/*
Functions to handle space-packed-records and blobs
A row may be stored in one or more linked blocks.
The block size is between MI_MIN_BLOCK_LENGTH and MI_MAX_BLOCK_LENGTH.
Each block is aligned on MI_DYN_ALIGN_SIZE.
The reson for the max block size is to not have too many different types
of blocks. For the differnet block types, look at _mi_get_block_info()
*/
#include "myisamdef.h"
#include <assert.h>
@ -264,6 +272,48 @@ static bool unlink_deleted_block(MI_INFO *info, MI_BLOCK_INFO *block_info)
DBUG_RETURN(0);
}
/*
Add a backward link to delete block
SYNOPSIS
update_backward_delete_link()
info MyISAM handler
delete_block Position to delete block to update.
If this is 'HA_OFFSET_ERROR', nothing will be done
filepos Position to block that 'delete_block' should point to
RETURN
0 ok
1 error. In this case my_error is set.
*/
static int update_backward_delete_link(MI_INFO *info, my_off_t delete_block,
my_off_t filepos)
{
MI_BLOCK_INFO block_info;
DBUG_ENTER("update_backward_delete_link");
if (delete_block != HA_OFFSET_ERROR)
{
block_info.second_read=0;
if (_mi_get_block_info(&block_info,info->dfile,delete_block)
& BLOCK_DELETED)
{
char buff[8];
mi_sizestore(buff,filepos);
if (my_pwrite(info->dfile,buff, 8, delete_block+12, MYF(MY_NABP)))
DBUG_RETURN(1); /* Error on write */
}
else
{
my_errno=HA_ERR_WRONG_IN_RECORD;
DBUG_RETURN(1); /* Wrong delete link */
}
}
return 0;
}
/* Delete datarecord from database */
/* info->rec_cache.seek_not_done is updated in cmp_record */
@ -272,29 +322,12 @@ static int delete_dynamic_record(MI_INFO *info, my_off_t filepos,
{
uint length,b_type;
MI_BLOCK_INFO block_info,del_block;
int error=0;
int error;
my_bool remove_next_block;
DBUG_ENTER("delete_dynamic_record");
/* First add a link from the last block to the new one */
if (info->s->state.dellink != HA_OFFSET_ERROR)
{
block_info.second_read=0;
if (_mi_get_block_info(&block_info,info->dfile,info->s->state.dellink)
& BLOCK_DELETED)
{
char buff[8];
mi_sizestore(buff,filepos);
if (my_pwrite(info->dfile,buff,8,info->s->state.dellink+12,
MYF(MY_NABP)))
error=1; /* Error on write */
}
else
{
error=1; /* Wrong delete link */
my_errno=HA_ERR_WRONG_IN_RECORD;
}
}
error= update_backward_delete_link(info, info->s->state.dellink, filepos);
block_info.second_read=second_read;
do
@ -518,21 +551,11 @@ int _mi_write_part_record(MI_INFO *info,
*reclength-=(length-head_length);
*flag=6;
if (del_length && next_delete_block != HA_OFFSET_ERROR)
if (del_length)
{
/* link the next delete block to this */
MI_BLOCK_INFO del_block;
del_block.second_read=0;
if (!(_mi_get_block_info(&del_block,info->dfile,next_delete_block)
& BLOCK_DELETED))
{
my_errno=HA_ERR_WRONG_IN_RECORD;
goto err;
}
mi_sizestore(del_block.header+12,info->s->state.dellink);
if (my_pwrite(info->dfile,(char*) del_block.header+12,8,
next_delete_block+12,
MYF(MY_NABP)))
if (update_backward_delete_link(info, next_delete_block,
info->s->state.dellink))
goto err;
}
@ -574,6 +597,8 @@ static int update_dynamic_record(MI_INFO *info, my_off_t filepos, byte *record,
{
uint tmp=MY_ALIGN(reclength - length + 3 +
test(reclength >= 65520L),MI_DYN_ALIGN_SIZE);
/* Don't create a block bigger than MI_MAX_BLOCK_LENGTH */
tmp= min(length+tmp, MI_MAX_BLOCK_LENGTH)-length;
/* Check if we can extend this block */
if (block_info.filepos + block_info.block_len ==
info->state->data_file_length &&
@ -588,9 +613,15 @@ static int update_dynamic_record(MI_INFO *info, my_off_t filepos, byte *record,
info->update|= HA_STATE_WRITE_AT_END | HA_STATE_EXTEND_BLOCK;
length+=tmp;
}
else
else if (length < MI_MAX_BLOCK_LENGTH - MI_MIN_BLOCK_LENGTH)
{
/* Check if next block is a deleted block */
/*
Check if next block is a deleted block
Above we have MI_MIN_BLOCK_LENGTH to avoid the problem where
the next block is so small it can't be splited which could
casue problems
*/
MI_BLOCK_INFO del_block;
del_block.second_read=0;
if (_mi_get_block_info(&del_block,info->dfile,
@ -601,7 +632,35 @@ static int update_dynamic_record(MI_INFO *info, my_off_t filepos, byte *record,
DBUG_PRINT("info",("Extending current block"));
if (unlink_deleted_block(info,&del_block))
goto err;
length+=del_block.block_len;
if ((length+=del_block.block_len) > MI_MAX_BLOCK_LENGTH)
{
/*
New block was too big, link overflow part back to
delete list
*/
my_off_t next_pos;
ulong rest_length= length-MI_MAX_BLOCK_LENGTH;
set_if_bigger(rest_length, MI_MIN_BLOCK_LENGTH);
next_pos= del_block.filepos+ del_block.block_len - rest_length;
if (update_backward_delete_link(info, info->s->state.dellink,
next_pos))
DBUG_RETURN(1);
/* create delete link for data that didn't fit into the page */
del_block.header[0]=0;
mi_int3store(del_block.header+1, rest_length);
mi_sizestore(del_block.header+4,info->s->state.dellink);
bfill(del_block.header+12,8,255);
if (my_pwrite(info->dfile,(byte*) del_block.header,20, next_pos,
MYF(MY_NABP)))
DBUG_RETURN(1);
info->s->state.dellink= next_pos;
info->s->state.split++;
info->state->del++;
info->state->empty+= rest_length;
length-= rest_length;
}
}
}
}
@ -615,7 +674,10 @@ static int update_dynamic_record(MI_INFO *info, my_off_t filepos, byte *record,
&record,&reclength,&flag))
goto err;
if ((filepos=block_info.next_filepos) == HA_OFFSET_ERROR)
{
/* Start writing data on deleted blocks */
filepos=info->s->state.dellink;
}
}
if (block_info.next_filepos != HA_OFFSET_ERROR)

27
mysql-test/r/myisam-blob.result Normal file
View File

@ -0,0 +1,27 @@
drop table if exists t1;
CREATE TABLE t1 (data LONGBLOB) ENGINE=myisam;
INSERT INTO t1 (data) VALUES (NULL);
UPDATE t1 set data=repeat('a',18*1024*1024);
select length(data) from t1;
length(data)
18874368
delete from t1 where left(data,1)='a';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
truncate table t1;
INSERT INTO t1 (data) VALUES (repeat('a',1*1024*1024));
INSERT INTO t1 (data) VALUES (repeat('b',16*1024*1024-1024));
delete from t1 where left(data,1)='b';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
UPDATE t1 set data=repeat('c',17*1024*1024);
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
delete from t1 where left(data,1)='c';
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
drop table t1;

1
mysql-test/t/myisam-blob-master.opt Normal file
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@ -0,0 +1 @@
--max-allowed-packet=24M --skip-innodb --key-buffer-size=1M

30
mysql-test/t/myisam-blob.test Normal file
View File

@ -0,0 +1,30 @@
#
# Test bugs in the MyISAM code with blobs
#
--disable_warnings
drop table if exists t1;
--enable_warnings
# Bug #2159 (Problem with update of blob to > 16M)
CREATE TABLE t1 (data LONGBLOB) ENGINE=myisam;
INSERT INTO t1 (data) VALUES (NULL);
UPDATE t1 set data=repeat('a',18*1024*1024);
select length(data) from t1;
delete from t1 where left(data,1)='a';
check table t1;
truncate table t1;
INSERT INTO t1 (data) VALUES (repeat('a',1*1024*1024));
INSERT INTO t1 (data) VALUES (repeat('b',16*1024*1024-1024));
delete from t1 where left(data,1)='b';
check table t1;
# now we have two blocks in the table, first is a 1M record and second is
# a 16M delete block.
UPDATE t1 set data=repeat('c',17*1024*1024);
check table t1;
delete from t1 where left(data,1)='c';
check table t1;
drop table t1;