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

[Hai Zaar]

On Tue, Dec 16, 2008 at 12:18 PM, Artem Bityutskiy
<dedekind at infradead.org> wrote:
> On Tue, 2008-12-16 at 10:40 +0200, Hai Zaar wrote:
>> 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.
>
> Would be nice if you tried my patch and confirmed it works, because I
> did not test it.
I've tried the patch with the latest git version of mtd-utils and I
confirm that it works on ARM at91sam9260 board.
Thanks!

>
> From: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
> 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 |   32 +++++++++++++++++++++-----------
>  1 files changed, 21 insertions(+), 11 deletions(-)
>
> diff --git a/nandwrite.c b/nandwrite.c
> index fc23e85..b4bc871 100644
> --- a/nandwrite.c
> +++ b/nandwrite.c
> @@ -262,7 +262,6 @@ int main(int argc, char * const argv[])
>        struct nand_oobinfo old_oobinfo;
>
>        process_options(argc, argv);
> -
>        erase_buffer(oobbuf, sizeof(oobbuf));
>
>        if (pad && writeoob) {
> @@ -438,6 +437,8 @@ int main(int argc, char * const argv[])
>         * length or zero.
>         */
>        while (imglen && (mtdoffset < meminfo.size)) {
> +               int tinycnt = 0;
> +
>                // new eraseblock , check for bad block(s)
>                // Stay in the loop to be sure if the mtdoffset changes because
>                // of a bad block, that the next block that will be written to
> @@ -484,15 +485,17 @@ 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;
> -
>                        while(tinycnt < readlen) {
>                                cnt = read(ifd, writebuf + tinycnt, readlen - tinycnt);
>                                if (cnt == 0) { // EOF
> @@ -522,11 +525,18 @@ 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;
> +                       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