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?
> 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;
> + }
> +
> 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
Regards,
Sergei
Chief Architect MariaDB
and secur...@mariadb.org
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