[PATCH/RFC] remove len/ooblen confusion in MTD/NAND code: respin
Vitaly Wool
vwool at ru.mvista.com
Fri Nov 3 10:20:38 EST 2006
Hello folks,
as was discussed between Ricard Wanderlof, David Woodhouse, Artem Bityutskiy and me, the current API for reading/writing OOB is confusing. The thing that introduces confusion is the need to specify ops.len together with ops.ooblen for reads/writes that concern only OOB not data area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to specify the length of the data read, and when ops.datbuf == NULL, it serves to specify the full OOB read length.
The patch inlined below is the slightly updated version of the previous patch serving the same purpose, but with the new Artem's comments taken into account.
Artem, BTW, thanks a lot for your valuable input!
drivers/mtd/inftlcore.c | 6 +----
drivers/mtd/mtdchar.c | 12 ++++-------
drivers/mtd/mtdconcat.c | 39 +++++++++++++++++++++++---------------
drivers/mtd/mtdpart.c | 4 +--
drivers/mtd/nand/nand_base.c | 44 ++++++++++++++++++++++++++++---------------
drivers/mtd/nand/nand_bbt.c | 5 +---
drivers/mtd/nftlcore.c | 6 +----
drivers/mtd/ssfdc.c | 5 +---
fs/jffs2/wbuf.c | 21 ++++++++------------
include/linux/mtd/mtd.h | 12 ++++-------
10 files changed, 82 insertions(+), 72 deletions(-)
Signed-off-by: Vitaly Wool <vwool at ru.mvista.com>
Index: linux-2.6/drivers/mtd/inftlcore.c
===================================================================
--- linux-2.6.orig/drivers/mtd/inftlcore.c
+++ linux-2.6/drivers/mtd/inftlcore.c
@@ -163,10 +163,9 @@ int inftl_read_oob(struct mtd_info *mtd,
ops.ooblen = len;
ops.oobbuf = buf;
ops.datbuf = NULL;
- ops.len = len;
res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
- *retlen = ops.retlen;
+ *retlen = ops.oobretlen;
return res;
}
@@ -184,10 +183,9 @@ int inftl_write_oob(struct mtd_info *mtd
ops.ooblen = len;
ops.oobbuf = buf;
ops.datbuf = NULL;
- ops.len = len;
res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
- *retlen = ops.retlen;
+ *retlen = ops.oobretlen;
return res;
}
Index: linux-2.6/drivers/mtd/nand/nand_base.c
===================================================================
--- linux-2.6.orig/drivers/mtd/nand/nand_base.c
+++ linux-2.6/drivers/mtd/nand/nand_base.c
@@ -897,12 +897,11 @@ static int nand_read_page_syndrome(struc
* @chip: nand chip structure
* @oob: oob destination address
* @ops: oob ops structure
+ * @len: size of oob to transfer
*/
static uint8_t *nand_transfer_oob(struct nand_chip *chip, uint8_t *oob,
- struct mtd_oob_ops *ops)
+ struct mtd_oob_ops *ops, size_t len)
{
- size_t len = ops->ooblen;
-
switch(ops->mode) {
case MTD_OOB_PLACE:
@@ -1008,9 +1007,12 @@ static int nand_do_read_ops(struct mtd_i
if (unlikely(oob)) {
/* Raw mode does data:oob:data:oob */
if (ops->mode != MTD_OOB_RAW)
- oob = nand_transfer_oob(chip, oob, ops);
+ oob = nand_transfer_oob(chip,
+ oob, ops,
+ chip->ecc.layout->oobavail);
else
- buf = nand_transfer_oob(chip, buf, ops);
+ buf = nand_transfer_oob(chip,
+ buf, ops, mtd->oobsize);
}
if (!(chip->options & NAND_NO_READRDY)) {
@@ -1057,6 +1059,8 @@ static int nand_do_read_ops(struct mtd_i
}
ops->retlen = ops->len - (size_t) readlen;
+ if (oob)
+ ops->oobretlen = ops->ooblen;
if (ret)
return ret;
@@ -1257,12 +1261,18 @@ static int nand_do_read_oob(struct mtd_i
int page, realpage, chipnr, sndcmd = 1;
struct nand_chip *chip = mtd->priv;
int blkcheck = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
- int readlen = ops->len;
+ int readlen = ops->ooblen;
+ int len;
uint8_t *buf = ops->oobbuf;
DEBUG(MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08Lx, len = %i\n",
(unsigned long long)from, readlen);
+ if (ops->mode == MTD_OOB_RAW)
+ len = mtd->oobsize;
+ else
+ len = chip->ecc.layout->oobavail;
+
chipnr = (int)(from >> chip->chip_shift);
chip->select_chip(mtd, chipnr);
@@ -1274,7 +1284,9 @@ static int nand_do_read_oob(struct mtd_i
while(1) {
sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);
- buf = nand_transfer_oob(chip, buf, ops);
+
+ len = min(len, readlen);
+ buf = nand_transfer_oob(chip, buf, ops, len);
if (!(chip->options & NAND_NO_READRDY)) {
/*
@@ -1289,7 +1301,7 @@ static int nand_do_read_oob(struct mtd_i
nand_wait_ready(mtd);
}
- readlen -= ops->ooblen;
+ readlen -= len;
if (!readlen)
break;
@@ -1311,7 +1323,7 @@ static int nand_do_read_oob(struct mtd_i
sndcmd = 1;
}
- ops->retlen = ops->len;
+ ops->oobretlen = ops->ooblen;
return 0;
}
@@ -1332,7 +1344,7 @@ static int nand_read_oob(struct mtd_info
ops->retlen = 0;
/* Do not allow reads past end of device */
- if ((from + ops->len) > mtd->size) {
+ if (ops->datbuf && (from + ops->len) > mtd->size) {
DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
"Attempt read beyond end of device\n");
return -EINVAL;
@@ -1654,8 +1666,10 @@ static int nand_do_write_ops(struct mtd_
}
}
- if (unlikely(oob))
+ if (unlikely(oob)) {
memset(chip->oob_poi, 0xff, mtd->oobsize);
+ ops->oobretlen = ops->ooblen;
+ }
ops->retlen = ops->len - writelen;
return ret;
@@ -1713,10 +1727,10 @@ static int nand_do_write_oob(struct mtd_
struct nand_chip *chip = mtd->priv;
DEBUG(MTD_DEBUG_LEVEL3, "nand_write_oob: to = 0x%08x, len = %i\n",
- (unsigned int)to, (int)ops->len);
+ (unsigned int)to, (int)ops->ooblen);
/* Do not allow write past end of page */
- if ((ops->ooboffs + ops->len) > mtd->oobsize) {
+ if ((ops->ooboffs + ops->ooblen) > mtd->oobsize) {
DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: "
"Attempt to write past end of page\n");
return -EINVAL;
@@ -1753,7 +1767,7 @@ static int nand_do_write_oob(struct mtd_
if (status)
return status;
- ops->retlen = ops->len;
+ ops->oobretlen = ops->ooblen;
return 0;
}
@@ -1773,7 +1787,7 @@ static int nand_write_oob(struct mtd_inf
ops->retlen = 0;
/* Do not allow writes past end of device */
- if ((to + ops->len) > mtd->size) {
+ if (ops->datbuf && (to + ops->len) > mtd->size) {
DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: "
"Attempt read beyond end of device\n");
return -EINVAL;
Index: linux-2.6/drivers/mtd/mtdchar.c
===================================================================
--- linux-2.6.orig/drivers/mtd/mtdchar.c
+++ linux-2.6/drivers/mtd/mtdchar.c
@@ -499,13 +499,12 @@ static int mtd_ioctl(struct inode *inode
if (ret)
return ret;
- ops.len = buf.length;
ops.ooblen = buf.length;
ops.ooboffs = buf.start & (mtd->oobsize - 1);
ops.datbuf = NULL;
ops.mode = MTD_OOB_PLACE;
- if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs))
+ if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
return -EINVAL;
ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
@@ -520,7 +519,7 @@ static int mtd_ioctl(struct inode *inode
buf.start &= ~(mtd->oobsize - 1);
ret = mtd->write_oob(mtd, buf.start, &ops);
- if (copy_to_user(argp + sizeof(uint32_t), &ops.retlen,
+ if (copy_to_user(argp + sizeof(uint32_t), &ops.oobretlen,
sizeof(uint32_t)))
ret = -EFAULT;
@@ -548,7 +547,6 @@ static int mtd_ioctl(struct inode *inode
if (ret)
return ret;
- ops.len = buf.length;
ops.ooblen = buf.length;
ops.ooboffs = buf.start & (mtd->oobsize - 1);
ops.datbuf = NULL;
@@ -564,10 +562,10 @@ static int mtd_ioctl(struct inode *inode
buf.start &= ~(mtd->oobsize - 1);
ret = mtd->read_oob(mtd, buf.start, &ops);
- if (put_user(ops.retlen, (uint32_t __user *)argp))
+ if (put_user(ops.oobretlen, (uint32_t __user *)argp))
ret = -EFAULT;
- else if (ops.retlen && copy_to_user(buf.ptr, ops.oobbuf,
- ops.retlen))
+ else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
+ ops.oobretlen))
ret = -EFAULT;
kfree(ops.oobbuf);
Index: linux-2.6/drivers/mtd/mtdconcat.c
===================================================================
--- linux-2.6.orig/drivers/mtd/mtdconcat.c
+++ linux-2.6/drivers/mtd/mtdconcat.c
@@ -247,7 +247,7 @@ concat_read_oob(struct mtd_info *mtd, lo
struct mtd_oob_ops devops = *ops;
int i, err, ret = 0;
- ops->retlen = 0;
+ ops->retlen = ops->oobretlen = 0;
for (i = 0; i < concat->num_subdev; i++) {
struct mtd_info *subdev = concat->subdev[i];
@@ -263,6 +263,7 @@ concat_read_oob(struct mtd_info *mtd, lo
err = subdev->read_oob(subdev, from, &devops);
ops->retlen += devops.retlen;
+ ops->oobretlen += devops.oobretlen;
/* Save information about bitflips! */
if (unlikely(err)) {
@@ -278,14 +279,18 @@ concat_read_oob(struct mtd_info *mtd, lo
return err;
}
- devops.len = ops->len - ops->retlen;
- if (!devops.len)
- return ret;
-
- if (devops.datbuf)
+ if (devops.datbuf) {
+ devops.len = ops->len - ops->retlen;
+ if (!devops.len)
+ return ret;
devops.datbuf += devops.retlen;
- if (devops.oobbuf)
- devops.oobbuf += devops.ooblen;
+ }
+ if (devops.oobbuf) {
+ devops.ooblen = ops->ooblen - ops->oobretlen;
+ if (!devops.ooblen)
+ return ret;
+ devops.oobbuf += ops->oobretlen;
+ }
from = 0;
}
@@ -321,14 +326,18 @@ concat_write_oob(struct mtd_info *mtd, l
if (err)
return err;
- devops.len = ops->len - ops->retlen;
- if (!devops.len)
- return 0;
-
- if (devops.datbuf)
+ if (devops.datbuf) {
+ devops.len = ops->len - ops->retlen;
+ if (!devops.len)
+ return 0;
devops.datbuf += devops.retlen;
- if (devops.oobbuf)
- devops.oobbuf += devops.ooblen;
+ }
+ if (devops.oobbuf) {
+ devops.ooblen = ops->ooblen - ops->oobretlen;
+ if (!devops.ooblen)
+ return 0;
+ devops.oobbuf += devops.oobretlen;
+ }
to = 0;
}
return -EINVAL;
Index: linux-2.6/drivers/mtd/nand/nand_bbt.c
===================================================================
--- linux-2.6.orig/drivers/mtd/nand/nand_bbt.c
+++ linux-2.6/drivers/mtd/nand/nand_bbt.c
@@ -333,7 +333,6 @@ static int scan_block_fast(struct mtd_in
struct mtd_oob_ops ops;
int j, ret;
- ops.len = mtd->oobsize;
ops.ooblen = mtd->oobsize;
ops.oobbuf = buf;
ops.ooboffs = 0;
@@ -676,10 +675,10 @@ static int write_bbt(struct mtd_info *mt
"bad block table\n");
}
/* Read oob data */
- ops.len = (len >> this->page_shift) * mtd->oobsize;
+ ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
ops.oobbuf = &buf[len];
res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
- if (res < 0 || ops.retlen != ops.len)
+ if (res < 0 || ops.oobretlen != ops.ooblen)
goto outerr;
/* Calc the byte offset in the buffer */
Index: linux-2.6/drivers/mtd/nftlcore.c
===================================================================
--- linux-2.6.orig/drivers/mtd/nftlcore.c
+++ linux-2.6/drivers/mtd/nftlcore.c
@@ -147,10 +147,9 @@ int nftl_read_oob(struct mtd_info *mtd,
ops.ooblen = len;
ops.oobbuf = buf;
ops.datbuf = NULL;
- ops.len = len;
res = mtd->read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
- *retlen = ops.retlen;
+ *retlen = ops.oobretlen;
return res;
}
@@ -168,10 +167,9 @@ int nftl_write_oob(struct mtd_info *mtd,
ops.ooblen = len;
ops.oobbuf = buf;
ops.datbuf = NULL;
- ops.len = len;
res = mtd->write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
- *retlen = ops.retlen;
+ *retlen = ops.oobretlen;
return res;
}
Index: linux-2.6/drivers/mtd/ssfdc.c
===================================================================
--- linux-2.6.orig/drivers/mtd/ssfdc.c
+++ linux-2.6/drivers/mtd/ssfdc.c
@@ -172,13 +172,12 @@ static int read_raw_oob(struct mtd_info
ops.mode = MTD_OOB_RAW;
ops.ooboffs = 0;
- ops.ooblen = mtd->oobsize;
- ops.len = OOB_SIZE;
+ ops.ooblen = OOB_SIZE;
ops.oobbuf = buf;
ops.datbuf = NULL;
ret = mtd->read_oob(mtd, offs, &ops);
- if (ret < 0 || ops.retlen != OOB_SIZE)
+ if (ret < 0 || ops.oobretlen != OOB_SIZE)
return -1;
return 0;
Index: linux-2.6/fs/jffs2/wbuf.c
===================================================================
--- linux-2.6.orig/fs/jffs2/wbuf.c
+++ linux-2.6/fs/jffs2/wbuf.c
@@ -968,8 +968,7 @@ int jffs2_check_oob_empty(struct jffs2_s
int oobsize = c->mtd->oobsize;
struct mtd_oob_ops ops;
- ops.len = NR_OOB_SCAN_PAGES * oobsize;
- ops.ooblen = oobsize;
+ ops.ooblen = NR_OOB_SCAN_PAGES * oobsize;
ops.oobbuf = c->oobbuf;
ops.ooboffs = 0;
ops.datbuf = NULL;
@@ -982,10 +981,10 @@ int jffs2_check_oob_empty(struct jffs2_s
return ret;
}
- if (ops.retlen < ops.len) {
+ if (ops.oobretlen < ops.ooblen) {
D1(printk(KERN_WARNING "jffs2_check_oob_empty(): Read OOB "
"returned short read (%zd bytes not %d) for block "
- "at %08x\n", ops.retlen, ops.len, jeb->offset));
+ "at %08x\n", ops.oobretlen, ops.ooblen, jeb->offset));
return -EIO;
}
@@ -1004,7 +1003,7 @@ int jffs2_check_oob_empty(struct jffs2_s
}
/* we know, we are aligned :) */
- for (page = oobsize; page < ops.len; page += sizeof(long)) {
+ for (page = oobsize; page < ops.ooblen; page += sizeof(long)) {
long dat = *(long *)(&ops.oobbuf[page]);
if(dat != -1)
return 1;
@@ -1032,7 +1031,6 @@ int jffs2_check_nand_cleanmarker (struct
return 2;
}
- ops.len = oobsize;
ops.ooblen = oobsize;
ops.oobbuf = c->oobbuf;
ops.ooboffs = 0;
@@ -1047,10 +1045,10 @@ int jffs2_check_nand_cleanmarker (struct
return ret;
}
- if (ops.retlen < ops.len) {
+ if (ops.oobretlen < ops.ooblen) {
D1 (printk (KERN_WARNING "jffs2_check_nand_cleanmarker(): "
"Read OOB return short read (%zd bytes not %d) "
- "for block at %08x\n", ops.retlen, ops.len,
+ "for block at %08x\n", ops.oobretlen, ops.ooblen,
jeb->offset));
return -EIO;
}
@@ -1089,8 +1087,7 @@ int jffs2_write_nand_cleanmarker(struct
n.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER);
n.totlen = cpu_to_je32(8);
- ops.len = c->fsdata_len;
- ops.ooblen = c->fsdata_len;;
+ ops.ooblen = c->fsdata_len;
ops.oobbuf = (uint8_t *)&n;
ops.ooboffs = c->fsdata_pos;
ops.datbuf = NULL;
@@ -1104,10 +1101,10 @@ int jffs2_write_nand_cleanmarker(struct
jeb->offset, ret));
return ret;
}
- if (ops.retlen != ops.len) {
+ if (ops.oobretlen != ops.ooblen) {
D1(printk(KERN_WARNING "jffs2_write_nand_cleanmarker(): "
"Short write for block at %08x: %zd not %d\n",
- jeb->offset, ops.retlen, ops.len));
+ jeb->offset, ops.oobretlen, ops.ooblen));
return -EIO;
}
return 0;
Index: linux-2.6/drivers/mtd/mtdpart.c
===================================================================
--- linux-2.6.orig/drivers/mtd/mtdpart.c
+++ linux-2.6/drivers/mtd/mtdpart.c
@@ -94,7 +94,7 @@ static int part_read_oob(struct mtd_info
if (from >= mtd->size)
return -EINVAL;
- if (from + ops->len > mtd->size)
+ if (ops->datbuf && from + ops->len > mtd->size)
return -EINVAL;
res = part->master->read_oob(part->master, from + part->offset, ops);
@@ -161,7 +161,7 @@ static int part_write_oob(struct mtd_inf
if (to >= mtd->size)
return -EINVAL;
- if (to + ops->len > mtd->size)
+ if (ops->datbuf && to + ops->len > mtd->size)
return -EINVAL;
return part->master->write_oob(part->master, to + part->offset, ops);
}
Index: linux-2.6/include/linux/mtd/mtd.h
===================================================================
--- linux-2.6.orig/include/linux/mtd/mtd.h
+++ linux-2.6/include/linux/mtd/mtd.h
@@ -75,15 +75,12 @@ typedef enum {
* struct mtd_oob_ops - oob operation operands
* @mode: operation mode
*
- * @len: number of bytes to write/read. When a data buffer is given
- * (datbuf != NULL) this is the number of data bytes. When
- * no data buffer is available this is the number of oob bytes.
+ * @len: number of data bytes to write/read
*
- * @retlen: number of bytes written/read. When a data buffer is given
- * (datbuf != NULL) this is the number of data bytes. When
- * no data buffer is available this is the number of oob bytes.
+ * @retlen: number of data bytes written/read
*
- * @ooblen: number of oob bytes per page
+ * @ooblen: number of oob bytes to write/read
+ * @oobretlen: number of oob bytes written/read
* @ooboffs: offset of oob data in the oob area (only relevant when
* mode = MTD_OOB_PLACE)
* @datbuf: data buffer - if NULL only oob data are read/written
@@ -94,6 +91,7 @@ struct mtd_oob_ops {
size_t len;
size_t retlen;
size_t ooblen;
+ size_t oobretlen;
uint32_t ooboffs;
uint8_t *datbuf;
uint8_t *oobbuf;
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