wbuf.c

linux 内核源代码

		outvec_to += wbuf_retlen;
		donelen += wbuf_retlen;
		v += wbuf_retlen;

		if (vlen >= c->wbuf_pagesize) {
			ret = c->mtd->write(c->mtd, outvec_to, PAGE_DIV(vlen),
					    &wbuf_retlen, v);
			if (ret < 0 || wbuf_retlen != PAGE_DIV(vlen))
				goto outfile;

			vlen -= wbuf_retlen;
			outvec_to += wbuf_retlen;
			c->wbuf_ofs = outvec_to;
			donelen += wbuf_retlen;
			v += wbuf_retlen;
		}

		wbuf_retlen = jffs2_fill_wbuf(c, v, vlen);
		if (c->wbuf_len == c->wbuf_pagesize) {
			ret = __jffs2_flush_wbuf(c, NOPAD);
			if (ret)
				goto outerr;
		}

		outvec_to += wbuf_retlen;
		donelen += wbuf_retlen;
	}

	/*
	 * If there's a remainder in the wbuf and it's a non-GC write,
	 * remember that the wbuf affects this ino
	 */
	*retlen = donelen;

	if (jffs2_sum_active()) {
		int res = jffs2_sum_add_kvec(c, invecs, count, (uint32_t) to);
		if (res)
			return res;
	}

	if (c->wbuf_len && ino)
		jffs2_wbuf_dirties_inode(c, ino);

	ret = 0;
	up_write(&c->wbuf_sem);
	return ret;

outfile:
	/*
	 * At this point we have no problem, c->wbuf is empty. However
	 * refile nextblock to avoid writing again to same address.
	 */

	spin_lock(&c->erase_completion_lock);

	jeb = &c->blocks[outvec_to / c->sector_size];
	jffs2_block_refile(c, jeb, REFILE_ANYWAY);

	spin_unlock(&c->erase_completion_lock);

outerr:
	*retlen = 0;
	up_write(&c->wbuf_sem);
	return ret;
}

/*
 *	This is the entry for flash write.
 *	Check, if we work on NAND FLASH, if so build an kvec and write it via vritev
*/
int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
		      size_t *retlen, const u_char *buf)
{
	struct kvec vecs[1];

	if (!jffs2_is_writebuffered(c))
		return jffs2_flash_direct_write(c, ofs, len, retlen, buf);

	vecs[0].iov_base = (unsigned char *) buf;
	vecs[0].iov_len = len;
	return jffs2_flash_writev(c, vecs, 1, ofs, retlen, 0);
}

/*
	Handle readback from writebuffer and ECC failure return
*/
int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *retlen, u_char *buf)
{
	loff_t	orbf = 0, owbf = 0, lwbf = 0;
	int	ret;

	if (!jffs2_is_writebuffered(c))
		return c->mtd->read(c->mtd, ofs, len, retlen, buf);

	/* Read flash */
	down_read(&c->wbuf_sem);
	ret = c->mtd->read(c->mtd, ofs, len, retlen, buf);

	if ( (ret == -EBADMSG || ret == -EUCLEAN) && (*retlen == len) ) {
		if (ret == -EBADMSG)
			printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx)"
			       " returned ECC error\n", len, ofs);
		/*
		 * We have the raw data without ECC correction in the buffer,
		 * maybe we are lucky and all data or parts are correct. We
		 * check the node.  If data are corrupted node check will sort
		 * it out.  We keep this block, it will fail on write or erase
		 * and the we mark it bad. Or should we do that now? But we
		 * should give him a chance.  Maybe we had a system crash or
		 * power loss before the ecc write or a erase was completed.
		 * So we return success. :)
		 */
		ret = 0;
	}

	/* if no writebuffer available or write buffer empty, return */
	if (!c->wbuf_pagesize || !c->wbuf_len)
		goto exit;

	/* if we read in a different block, return */
	if (SECTOR_ADDR(ofs) != SECTOR_ADDR(c->wbuf_ofs))
		goto exit;

	if (ofs >= c->wbuf_ofs) {
		owbf = (ofs - c->wbuf_ofs);	/* offset in write buffer */
		if (owbf > c->wbuf_len)		/* is read beyond write buffer ? */
			goto exit;
		lwbf = c->wbuf_len - owbf;	/* number of bytes to copy */
		if (lwbf > len)
			lwbf = len;
	} else {
		orbf = (c->wbuf_ofs - ofs);	/* offset in read buffer */
		if (orbf > len)			/* is write beyond write buffer ? */
			goto exit;
		lwbf = len - orbf;		/* number of bytes to copy */
		if (lwbf > c->wbuf_len)
			lwbf = c->wbuf_len;
	}
	if (lwbf > 0)
		memcpy(buf+orbf,c->wbuf+owbf,lwbf);

exit:
	up_read(&c->wbuf_sem);
	return ret;
}

#define NR_OOB_SCAN_PAGES 4

/* For historical reasons we use only 8 bytes for OOB clean marker */
#define OOB_CM_SIZE 8

static const struct jffs2_unknown_node oob_cleanmarker =
{
	.magic = constant_cpu_to_je16(JFFS2_MAGIC_BITMASK),
	.nodetype = constant_cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER),
	.totlen = constant_cpu_to_je32(8)
};

/*
 * Check, if the out of band area is empty. This function knows about the clean
 * marker and if it is present in OOB, treats the OOB as empty anyway.
 */
int jffs2_check_oob_empty(struct jffs2_sb_info *c,
			  struct jffs2_eraseblock *jeb, int mode)
{
	int i, ret;
	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
	struct mtd_oob_ops ops;

	ops.mode = MTD_OOB_AUTO;
	ops.ooblen = NR_OOB_SCAN_PAGES * c->oobavail;
	ops.oobbuf = c->oobbuf;
	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
	ops.datbuf = NULL;

	ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
	if (ret || ops.oobretlen != ops.ooblen) {
		printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
				" bytes, read %zd bytes, error %d\n",
				jeb->offset, ops.ooblen, ops.oobretlen, ret);
		if (!ret)
			ret = -EIO;
		return ret;
	}

	for(i = 0; i < ops.ooblen; i++) {
		if (mode && i < cmlen)
			/* Yeah, we know about the cleanmarker */
			continue;

		if (ops.oobbuf[i] != 0xFF) {
			D2(printk(KERN_DEBUG "Found %02x at %x in OOB for "
				  "%08x\n", ops.oobbuf[i], i, jeb->offset));
			return 1;
		}
	}

	return 0;
}

/*
 * Check for a valid cleanmarker.
 * Returns: 0 if a valid cleanmarker was found
 *	    1 if no cleanmarker was found
 *	    negative error code if an error occurred
 */
int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c,
				 struct jffs2_eraseblock *jeb)
{
	struct mtd_oob_ops ops;
	int ret, cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);

	ops.mode = MTD_OOB_AUTO;
	ops.ooblen = cmlen;
	ops.oobbuf = c->oobbuf;
	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
	ops.datbuf = NULL;

	ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
	if (ret || ops.oobretlen != ops.ooblen) {
		printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
				" bytes, read %zd bytes, error %d\n",
				jeb->offset, ops.ooblen, ops.oobretlen, ret);
		if (!ret)
			ret = -EIO;
		return ret;
	}

	return !!memcmp(&oob_cleanmarker, c->oobbuf, cmlen);
}

int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c,
				 struct jffs2_eraseblock *jeb)
{
	int ret;
	struct mtd_oob_ops ops;
	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);

	ops.mode = MTD_OOB_AUTO;
	ops.ooblen = cmlen;
	ops.oobbuf = (uint8_t *)&oob_cleanmarker;
	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
	ops.datbuf = NULL;

	ret = c->mtd->write_oob(c->mtd, jeb->offset, &ops);
	if (ret || ops.oobretlen != ops.ooblen) {
		printk(KERN_ERR "cannot write OOB for EB at %08x, requested %zd"
				" bytes, read %zd bytes, error %d\n",
				jeb->offset, ops.ooblen, ops.oobretlen, ret);
		if (!ret)
			ret = -EIO;
		return ret;
	}

	return 0;
}

/*
 * On NAND we try to mark this block bad. If the block was erased more
 * than MAX_ERASE_FAILURES we mark it finaly bad.
 * Don't care about failures. This block remains on the erase-pending
 * or badblock list as long as nobody manipulates the flash with
 * a bootloader or something like that.
 */

int jffs2_write_nand_badblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t bad_offset)
{
	int 	ret;

	/* if the count is < max, we try to write the counter to the 2nd page oob area */
	if( ++jeb->bad_count < MAX_ERASE_FAILURES)
		return 0;

	if (!c->mtd->block_markbad)
		return 1; // What else can we do?

	printk(KERN_WARNING "JFFS2: marking eraseblock at %08x\n as bad", bad_offset);
	ret = c->mtd->block_markbad(c->mtd, bad_offset);

	if (ret) {
		D1(printk(KERN_WARNING "jffs2_write_nand_badblock(): Write failed for block at %08x: error %d\n", jeb->offset, ret));
		return ret;
	}
	return 1;
}

int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
{
	struct nand_ecclayout *oinfo = c->mtd->ecclayout;

	if (!c->mtd->oobsize)
		return 0;

	/* Cleanmarker is out-of-band, so inline size zero */
	c->cleanmarker_size = 0;

	if (!oinfo || oinfo->oobavail == 0) {
		printk(KERN_ERR "inconsistent device description\n");
		return -EINVAL;
	}

	D1(printk(KERN_DEBUG "JFFS2 using OOB on NAND\n"));

	c->oobavail = oinfo->oobavail;

	/* Initialise write buffer */
	init_rwsem(&c->wbuf_sem);
	c->wbuf_pagesize = c->mtd->writesize;
	c->wbuf_ofs = 0xFFFFFFFF;

	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
	if (!c->wbuf)
		return -ENOMEM;

	c->oobbuf = kmalloc(NR_OOB_SCAN_PAGES * c->oobavail, GFP_KERNEL);
	if (!c->oobbuf) {
		kfree(c->wbuf);
		return -ENOMEM;
	}

#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
	c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
	if (!c->wbuf_verify) {
		kfree(c->oobbuf);
		kfree(c->wbuf);
		return -ENOMEM;
	}
#endif
	return 0;
}

void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c)
{
#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
	kfree(c->wbuf_verify);
#endif
	kfree(c->wbuf);
	kfree(c->oobbuf);
}

int jffs2_dataflash_setup(struct jffs2_sb_info *c) {
	c->cleanmarker_size = 0;		/* No cleanmarkers needed */

	/* Initialize write buffer */
	init_rwsem(&c->wbuf_sem);


	c->wbuf_pagesize =  c->mtd->erasesize;

	/* Find a suitable c->sector_size
	 * - Not too much sectors
	 * - Sectors have to be at least 4 K + some bytes
	 * - All known dataflashes have erase sizes of 528 or 1056
	 * - we take at least 8 eraseblocks and want to have at least 8K size
	 * - The concatenation should be a power of 2
	*/

	c->sector_size = 8 * c->mtd->erasesize;

	while (c->sector_size < 8192) {
		c->sector_size *= 2;
	}

	/* It may be necessary to adjust the flash size */
	c->flash_size = c->mtd->size;

	if ((c->flash_size % c->sector_size) != 0) {
		c->flash_size = (c->flash_size / c->sector_size) * c->sector_size;
		printk(KERN_WARNING "JFFS2 flash size adjusted to %dKiB\n", c->flash_size);
	};

	c->wbuf_ofs = 0xFFFFFFFF;
	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
	if (!c->wbuf)
		return -ENOMEM;

	printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size);

	return 0;
}

void jffs2_dataflash_cleanup(struct jffs2_sb_info *c) {
	kfree(c->wbuf);
}

int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c) {
	/* Cleanmarker currently occupies whole programming regions,
	 * either one or 2 for 8Byte STMicro flashes. */
	c->cleanmarker_size = max(16u, c->mtd->writesize);

	/* Initialize write buffer */
	init_rwsem(&c->wbuf_sem);
	c->wbuf_pagesize = c->mtd->writesize;
	c->wbuf_ofs = 0xFFFFFFFF;

	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
	if (!c->wbuf)
		return -ENOMEM;

	return 0;
}

void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c) {
	kfree(c->wbuf);
}

int jffs2_ubivol_setup(struct jffs2_sb_info *c) {
	c->cleanmarker_size = 0;

	if (c->mtd->writesize == 1)
		/* We do not need write-buffer */
		return 0;

	init_rwsem(&c->wbuf_sem);

	c->wbuf_pagesize =  c->mtd->writesize;
	c->wbuf_ofs = 0xFFFFFFFF;
	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
	if (!c->wbuf)
		return -ENOMEM;

	printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size);

	return 0;
}

void jffs2_ubivol_cleanup(struct jffs2_sb_info *c) {
	kfree(c->wbuf);
}