Am 18.10.18 um 13:27 schrieb Sergei Golubchik:
Hi, Oleksandr!
On Oct 12, Oleksandr Byelkin wrote:
revision-id: cc5c19ae5233ba90de086de76043774ae6c78cd7
(mariadb-5.5.61-30-gcc5c19ae523)
parent(s): acf8fc1ff8a7b2d49e25279670b04b8eb096ce0c
author: Oleksandr Byelkin
committer: Oleksandr Byelkin
timestamp: 2018-10-12 09:07:05 +0200
message:
MDEV-17401: LOAD DATA from very big file into MyISAM table results in EOF error
and corrupt index
my_read fixed as in higher versions.
my_pread made as my_read aware of partial read of huge chunks of files
MY_FULL_IO enabled for file operations
---
mysys/mf_iocache.c | 4 ++++
mysys/my_pread.c | 25 ++++++++++++++++++-------
mysys/my_read.c | 52 ++++++++++++++++++++++++++++------------------------
3 files changed, 50 insertions(+), 31 deletions(-)
diff --git a/mysys/mf_iocache.c b/mysys/mf_iocache.c
index bd71e2ae527..9a051cf6a9e 100644
--- a/mysys/mf_iocache.c
+++ b/mysys/mf_iocache.c
@@ -282,6 +282,10 @@ int init_io_cache(IO_CACHE *info, File file, size_t
cachesize,
}
info->inited=info->aio_result.pending=0;
#endif
+ if (type == READ_CACHE || type == WRITE_CACHE || type == SEQ_READ_APPEND)
+ info->myflags|= MY_FULL_IO;
+ else
+ info->myflags&= ~MY_FULL_IO;
1. that's a bit redundant, it'd be enough to do it in init_io_cache.
but ok.
2. why you didn't remove MY_FULL_IO setting from reinit_io_cache?
it is 5.5 so there is no reinit_io_cache and there is no place where we
set MY_FULL_IO (it is not set at all, and this is why it had buggy
version for my_read).
DBUG_RETURN(0);
} /* init_io_cache */
diff --git a/mysys/my_pread.c b/mysys/my_pread.c
index 51b4c5f5599..5cbd6b4316b 100644
--- a/mysys/my_pread.c
+++ b/mysys/my_pread.c
@@ -47,8 +47,7 @@
size_t my_pread(File Filedes, uchar *Buffer, size_t Count, my_off_t offset,
myf MyFlags)
{
- size_t readbytes;
- int error= 0;
+ size_t readbytes, save_count= 0;
DBUG_ENTER("my_pread");
@@ -66,11 +65,10 @@ size_t my_pread(File Filedes, uchar *Buffer, size_t Count, my_off_t offset,
#else
readbytes= pread(Filedes, Buffer, Count, offset);
#endif
- error = (readbytes != Count);
- if (error)
+ if (readbytes != Count)
{
- my_errno= errno ? errno : -1;
+ my_errno= errno;
if (errno == 0 || (readbytes != (size_t) -1 &&
(MyFlags & (MY_NABP | MY_FNABP))))
my_errno= HA_ERR_FILE_TOO_SHORT;
@@ -82,6 +80,17 @@ size_t my_pread(File Filedes, uchar *Buffer, size_t Count,
my_off_t offset,
(int) readbytes));
continue; /* Interrupted */
}
+
+ /* Do a read retry if we didn't get enough data on first read */
+ if (readbytes != (size_t) -1 && readbytes != 0 &&
+ (MyFlags & MY_FULL_IO))
+ {
+ Buffer+= readbytes;
+ Count-= readbytes;
+ save_count+= readbytes;
+ continue;
eh, did you test your patch? I don't see how it could work without
offset+= readbytes;
it advance buffer pointer (as in correct version of my_read, we can not
advance both).
+ }
+
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
if (readbytes == (size_t) -1)
@@ -97,8 +106,10 @@ size_t my_pread(File Filedes, uchar *Buffer, size_t Count,
my_off_t offset,
DBUG_RETURN(MY_FILE_ERROR); /* Return with error */
}
if (MyFlags & (MY_NABP | MY_FNABP))
- DBUG_RETURN(0); /* Read went ok; Return 0 */
- DBUG_RETURN(readbytes); /* purecov: inspected */
+ readbytes= 0; /* Read went ok; Return 0 */
+ else
+ readbytes+= save_count;
+ DBUG_RETURN(readbytes);
}
} /* my_pread */
diff --git a/mysys/my_read.c b/mysys/my_read.c
index 883a1c5fdc7..47f2d725f65 100644
--- a/mysys/my_read.c
+++ b/mysys/my_read.c
@@ -35,17 +35,16 @@
this is copied from 10.1 verbatim, I presume
Actually 10.3 but they looks like the same.
Regards,
Sergei
Chief Architect MariaDB
and secur...@mariadb.org
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