From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-fx0-f49.google.com ([209.85.161.49]) by bombadil.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1OVzMm-0006Oz-HU for linux-mtd@lists.infradead.org; Tue, 06 Jul 2010 04:02:41 +0000 Received: by fxm3 with SMTP id 3so2949654fxm.36 for ; Mon, 05 Jul 2010 21:02:37 -0700 (PDT) Subject: Re: [PATCH 4/5] libmtd: add support for 64-bit offsets, OOB From: Artem Bityutskiy To: Kevin Cernekee In-Reply-To: References: <4822394121cd0a8f08b0bd3ecd6af199@localhost> Content-Type: text/plain; charset="UTF-8" Date: Tue, 06 Jul 2010 07:02:33 +0300 Message-Id: <1278388953.3599.39.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org, jwboyer@gmail.com, saeed.bishara@gmail.com Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2010-07-05 at 15:10 -0700, Kevin Cernekee wrote: > Change mtd_erase() so that it attempts to use MEMERASE64 first, then falls > back to the old <2.6.31 MEMERASE if MEMERASE64 is unsupported. > > Add mtd_read_oob(), mtd_write_oob() functions to wrap the OOB ioctls. > Similar ioctl fallback logic is used in these functions as well. > > Signed-off-by: Kevin Cernekee > --- > include/libmtd.h | 26 +++++++++++++++++++++ > lib/libmtd.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 88 insertions(+), 3 deletions(-) > > diff --git a/include/libmtd.h b/include/libmtd.h > index 0aea966..2241343 100644 > --- a/include/libmtd.h > +++ b/include/libmtd.h > @@ -149,6 +149,32 @@ int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd); > int mtd_erase(const struct mtd_dev_info *mtd, int fd, int eb); > > /** > + * mtd_read_oob - read OOB bytes > + * @fd: MTD device node file descriptor > + * @start: page-aligned start address > + * @length: number of OOB bytes to read > + * @data: read buffer > + * > + * This function reads @length OOB bytes starting from address @start on > + * MTD device described by @fd. Returns %0 in case of success and %-1 in > + * case of failure. > + */ > +int mtd_read_oob(int fd, uint64_t start, uint64_t length, void *data); > + > +/** > + * mtd_write_oob - write OOB bytes > + * @fd: MTD device node file descriptor > + * @start: page-aligned start address > + * @length: number of OOB bytes to write > + * @data: write buffer > + * > + * This function writes @length OOB bytes starting from address @start on > + * MTD device described by @fd. Returns %0 in case of success and %-1 in > + * case of failure. > + */ > +int mtd_write_oob(int fd, uint64_t start, uint64_t length, void *data); > + > +/** > * mtd_torture - torture an eraseblock. > * @mtd: MTD device description object > * @fd: MTD device node file descriptor > diff --git a/lib/libmtd.c b/lib/libmtd.c > index 3ff031c..368493b 100644 > --- a/lib/libmtd.c > +++ b/lib/libmtd.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > > #include > #include "libmtd_int.h" > @@ -791,11 +792,69 @@ int mtd_get_dev_info(libmtd_t desc, const char *node, struct mtd_dev_info *mtd) > > int mtd_erase(const struct mtd_dev_info *mtd, int fd, int eb) > { > - struct erase_info_user ei; > + int ret; > + struct erase_info_user64 ei; > > - ei.start = eb * mtd->eb_size;; > + ei.start = (__u64)eb * mtd->eb_size; > ei.length = mtd->eb_size; > - return ioctl(fd, MEMERASE, &ei); > + ret = ioctl(fd, MEMERASE64, &ei); > + > + if (ret < 0 && errno == ENOTTY) { > + struct erase_info_user ei_old; > + > + ei_old.start = (__u32)ei.start; > + ei_old.length = (__u32)ei.length; > + > + if (ei_old.start != ei.start) { > + errno = EOVERFLOW; > + return -1; > + } > + > + ret = ioctl(fd, MEMERASE, &ei_old); > + } > + > + return ret; > +} Kevin, looks like a good sanitization in general, thanks. But let's avoid calling 2 ioctls for old kernels - just introduce a flag in 'struct mtd_dev_info' and check whether 64-bit offsets are supported. -- Best Regards, Artem Bityutskiy (Артём Битюцкий)