[PATCH] nandwrite - handle situation when read returns less bytes the expected

[Hai Zaar]

On Tue, Dec 16, 2008 at 8:28 AM, Artem Bityutskiy
<dedekind at infradead.org> wrote:
>
> Your patch does not apply. It looks like it is not against the latest
> mtd-utils. How about this patch?
Yes, my patch is against mtd-utils-1.2.0. Yours is surely better since
it covers oob reading as well.

>
> From: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
> Date: Tue, 16 Dec 2008 10:02:16 +0200
> Subject: [PATCH] nandwrite: correct data reading
>
> The "read" syscall does not necessarily return all the requested
> data, in which case the caller has to try again and read more.
> Take this into account when reading input data.
>
> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
> ---
>  nandwrite.c |   31 +++++++++++++++++++++++--------
>  1 files changed, 23 insertions(+), 8 deletions(-)
>
> diff --git a/nandwrite.c b/nandwrite.c
> index fc23e85..0b2a9ee 100644
> --- a/nandwrite.c
> +++ b/nandwrite.c
> @@ -260,6 +260,7 @@ int main(int argc, char * const argv[])
>        int ret, readlen;
>        int oobinfochanged = 0;
>        struct nand_oobinfo old_oobinfo;
> +       int readcnt = 0;
>
>        process_options(argc, argv);
>
> @@ -477,6 +478,8 @@ int main(int argc, char * const argv[])
>                readlen = meminfo.writesize;
>
>                if (ifd != STDIN_FILENO) {
> +                       int tinycnt = 0;
> +
>                        if (pad && (imglen < readlen))
>                        {
>                                readlen = imglen;
> @@ -484,11 +487,15 @@ int main(int argc, char * const argv[])
>                        }
>
>                        /* Read Page Data from input file */
> -                       if ((cnt = read(ifd, writebuf, readlen)) != readlen) {
> -                               if (cnt == 0)   // EOF
> +                       while(tinycnt < readlen) {
> +                               cnt = read(ifd, writebuf + tinycnt, readlen - tinycnt);
> +                               if (cnt == 0) { // EOF
>                                        break;
> -                               perror ("File I/O error on input file");
> -                               goto closeall;
> +                               } else if (cnt < 0) {
> +                                       perror ("File I/O error on input file");
> +                                       goto closeall;
> +                               }
> +                               tinycnt += cnt;
>                        }
>                } else {
>                        int tinycnt = 0;
> @@ -522,11 +529,19 @@ int main(int argc, char * const argv[])
>                }
>
>                if (writeoob) {
> -                       /* Read OOB data from input file, exit on failure */
> -                       if ((cnt = read(ifd, oobreadbuf, meminfo.oobsize)) != meminfo.oobsize) {
> -                               perror ("File I/O error on input file");
> -                               goto closeall;
> +                       int tinycnt = 0;
> +
> +                       while(tinycnt < readlen) {
> +                               cnt = read(ifd, oobreadbuf + tinycnt, meminfo.oobsize - tinycnt);
> +                               if (cnt == 0) { // EOF
> +                                       break;
> +                               } else if (cnt < 0) {
> +                                       perror ("File I/O error on input file");
> +                                       goto closeall;
> +                               }
> +                               tinycnt += cnt;
>                        }
> +
>                        if (!noecc) {
>                                int i, start, len;
>                                /*
> --
> 1.5.4.3
>
> --
> Best regards,
> Artem Bityutskiy (Битюцкий Артём)
>
>



-- 
Zaar