wbuf.c

linux 内核源代码

			return;
		}
		printk(KERN_NOTICE "Recovery of wbuf succeeded to %08x\n", ofs);

		c->wbuf_len = (end - start) - towrite;
		c->wbuf_ofs = ofs + towrite;
		memmove(c->wbuf, rewrite_buf + towrite, c->wbuf_len);
		/* Don't muck about with c->wbuf_inodes. False positives are harmless. */
	} else {
		/* OK, now we're left with the dregs in whichever buffer we're using */
		if (buf) {
			memcpy(c->wbuf, buf, end-start);
		} else {
			memmove(c->wbuf, c->wbuf + (start - c->wbuf_ofs), end - start);
		}
		c->wbuf_ofs = ofs;
		c->wbuf_len = end - start;
	}

	/* Now sort out the jffs2_raw_node_refs, moving them from the old to the next block */
	new_jeb = &c->blocks[ofs / c->sector_size];

	spin_lock(&c->erase_completion_lock);
	for (raw = first_raw; raw != jeb->last_node; raw = ref_next(raw)) {
		uint32_t rawlen = ref_totlen(c, jeb, raw);
		struct jffs2_inode_cache *ic;
		struct jffs2_raw_node_ref *new_ref;
		struct jffs2_raw_node_ref **adjust_ref = NULL;
		struct jffs2_inode_info *f = NULL;

		D1(printk(KERN_DEBUG "Refiling block of %08x at %08x(%d) to %08x\n",
			  rawlen, ref_offset(raw), ref_flags(raw), ofs));

		ic = jffs2_raw_ref_to_ic(raw);

		/* Ick. This XATTR mess should be fixed shortly... */
		if (ic && ic->class == RAWNODE_CLASS_XATTR_DATUM) {
			struct jffs2_xattr_datum *xd = (void *)ic;
			BUG_ON(xd->node != raw);
			adjust_ref = &xd->node;
			raw->next_in_ino = NULL;
			ic = NULL;
		} else if (ic && ic->class == RAWNODE_CLASS_XATTR_REF) {
			struct jffs2_xattr_datum *xr = (void *)ic;
			BUG_ON(xr->node != raw);
			adjust_ref = &xr->node;
			raw->next_in_ino = NULL;
			ic = NULL;
		} else if (ic && ic->class == RAWNODE_CLASS_INODE_CACHE) {
			struct jffs2_raw_node_ref **p = &ic->nodes;

			/* Remove the old node from the per-inode list */
			while (*p && *p != (void *)ic) {
				if (*p == raw) {
					(*p) = (raw->next_in_ino);
					raw->next_in_ino = NULL;
					break;
				}
				p = &((*p)->next_in_ino);
			}

			if (ic->state == INO_STATE_PRESENT && !ref_obsolete(raw)) {
				/* If it's an in-core inode, then we have to adjust any
				   full_dirent or full_dnode structure to point to the
				   new version instead of the old */
				f = jffs2_gc_fetch_inode(c, ic->ino, ic->nlink);
				if (IS_ERR(f)) {
					/* Should never happen; it _must_ be present */
					JFFS2_ERROR("Failed to iget() ino #%u, err %ld\n",
						    ic->ino, PTR_ERR(f));
					BUG();
				}
				/* We don't lock f->sem. There's a number of ways we could
				   end up in here with it already being locked, and nobody's
				   going to modify it on us anyway because we hold the
				   alloc_sem. We're only changing one ->raw pointer too,
				   which we can get away with without upsetting readers. */
				adjust_ref = jffs2_incore_replace_raw(c, f, raw,
								      (void *)(buf?:c->wbuf) + (ref_offset(raw) - start));
			} else if (unlikely(ic->state != INO_STATE_PRESENT &&
					    ic->state != INO_STATE_CHECKEDABSENT &&
					    ic->state != INO_STATE_GC)) {
				JFFS2_ERROR("Inode #%u is in strange state %d!\n", ic->ino, ic->state);
				BUG();
			}
		}

		new_ref = jffs2_link_node_ref(c, new_jeb, ofs | ref_flags(raw), rawlen, ic);

		if (adjust_ref) {
			BUG_ON(*adjust_ref != raw);
			*adjust_ref = new_ref;
		}
		if (f)
			jffs2_gc_release_inode(c, f);

		if (!ref_obsolete(raw)) {
			jeb->dirty_size += rawlen;
			jeb->used_size  -= rawlen;
			c->dirty_size += rawlen;
			c->used_size -= rawlen;
			raw->flash_offset = ref_offset(raw) | REF_OBSOLETE;
			BUG_ON(raw->next_in_ino);
		}
		ofs += rawlen;
	}

	kfree(buf);

	/* Fix up the original jeb now it's on the bad_list */
	if (first_raw == jeb->first_node) {
		D1(printk(KERN_DEBUG "Failing block at %08x is now empty. Moving to erase_pending_list\n", jeb->offset));
		list_move(&jeb->list, &c->erase_pending_list);
		c->nr_erasing_blocks++;
		jffs2_erase_pending_trigger(c);
	}

	jffs2_dbg_acct_sanity_check_nolock(c, jeb);
	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);

	jffs2_dbg_acct_sanity_check_nolock(c, new_jeb);
	jffs2_dbg_acct_paranoia_check_nolock(c, new_jeb);

	spin_unlock(&c->erase_completion_lock);

	D1(printk(KERN_DEBUG "wbuf recovery completed OK. wbuf_ofs 0x%08x, len 0x%x\n", c->wbuf_ofs, c->wbuf_len));

}

/* Meaning of pad argument:
   0: Do not pad. Probably pointless - we only ever use this when we can't pad anyway.
   1: Pad, do not adjust nextblock free_size
   2: Pad, adjust nextblock free_size
*/
#define NOPAD		0
#define PAD_NOACCOUNT	1
#define PAD_ACCOUNTING	2

static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
{
	struct jffs2_eraseblock *wbuf_jeb;
	int ret;
	size_t retlen;

	/* Nothing to do if not write-buffering the flash. In particular, we shouldn't
	   del_timer() the timer we never initialised. */
	if (!jffs2_is_writebuffered(c))
		return 0;

	if (!down_trylock(&c->alloc_sem)) {
		up(&c->alloc_sem);
		printk(KERN_CRIT "jffs2_flush_wbuf() called with alloc_sem not locked!\n");
		BUG();
	}

	if (!c->wbuf_len)	/* already checked c->wbuf above */
		return 0;

	wbuf_jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
	if (jffs2_prealloc_raw_node_refs(c, wbuf_jeb, c->nextblock->allocated_refs + 1))
		return -ENOMEM;

	/* claim remaining space on the page
	   this happens, if we have a change to a new block,
	   or if fsync forces us to flush the writebuffer.
	   if we have a switch to next page, we will not have
	   enough remaining space for this.
	*/
	if (pad ) {
		c->wbuf_len = PAD(c->wbuf_len);

		/* Pad with JFFS2_DIRTY_BITMASK initially.  this helps out ECC'd NOR
		   with 8 byte page size */
		memset(c->wbuf + c->wbuf_len, 0, c->wbuf_pagesize - c->wbuf_len);

		if ( c->wbuf_len + sizeof(struct jffs2_unknown_node) < c->wbuf_pagesize) {
			struct jffs2_unknown_node *padnode = (void *)(c->wbuf + c->wbuf_len);
			padnode->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
			padnode->nodetype = cpu_to_je16(JFFS2_NODETYPE_PADDING);
			padnode->totlen = cpu_to_je32(c->wbuf_pagesize - c->wbuf_len);
			padnode->hdr_crc = cpu_to_je32(crc32(0, padnode, sizeof(*padnode)-4));
		}
	}
	/* else jffs2_flash_writev has actually filled in the rest of the
	   buffer for us, and will deal with the node refs etc. later. */

#ifdef BREAKME
	static int breakme;
	if (breakme++ == 20) {
		printk(KERN_NOTICE "Faking write error at 0x%08x\n", c->wbuf_ofs);
		breakme = 0;
		c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen,
			      brokenbuf);
		ret = -EIO;
	} else
#endif

		ret = c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen, c->wbuf);

	if (ret) {
		printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n", ret);
		goto wfail;
	} else if (retlen != c->wbuf_pagesize) {
		printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n",
		       retlen, c->wbuf_pagesize);
		ret = -EIO;
		goto wfail;
	} else if ((ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs))) {
	wfail:
		jffs2_wbuf_recover(c);

		return ret;
	}

	/* Adjust free size of the block if we padded. */
	if (pad) {
		uint32_t waste = c->wbuf_pagesize - c->wbuf_len;

		D1(printk(KERN_DEBUG "jffs2_flush_wbuf() adjusting free_size of %sblock at %08x\n",
			  (wbuf_jeb==c->nextblock)?"next":"", wbuf_jeb->offset));

		/* wbuf_pagesize - wbuf_len is the amount of space that's to be
		   padded. If there is less free space in the block than that,
		   something screwed up */
		if (wbuf_jeb->free_size < waste) {
			printk(KERN_CRIT "jffs2_flush_wbuf(): Accounting error. wbuf at 0x%08x has 0x%03x bytes, 0x%03x left.\n",
			       c->wbuf_ofs, c->wbuf_len, waste);
			printk(KERN_CRIT "jffs2_flush_wbuf(): But free_size for block at 0x%08x is only 0x%08x\n",
			       wbuf_jeb->offset, wbuf_jeb->free_size);
			BUG();
		}

		spin_lock(&c->erase_completion_lock);

		jffs2_link_node_ref(c, wbuf_jeb, (c->wbuf_ofs + c->wbuf_len) | REF_OBSOLETE, waste, NULL);
		/* FIXME: that made it count as dirty. Convert to wasted */
		wbuf_jeb->dirty_size -= waste;
		c->dirty_size -= waste;
		wbuf_jeb->wasted_size += waste;
		c->wasted_size += waste;
	} else
		spin_lock(&c->erase_completion_lock);

	/* Stick any now-obsoleted blocks on the erase_pending_list */
	jffs2_refile_wbuf_blocks(c);
	jffs2_clear_wbuf_ino_list(c);
	spin_unlock(&c->erase_completion_lock);

	memset(c->wbuf,0xff,c->wbuf_pagesize);
	/* adjust write buffer offset, else we get a non contiguous write bug */
	if (SECTOR_ADDR(c->wbuf_ofs) == SECTOR_ADDR(c->wbuf_ofs+c->wbuf_pagesize))
		c->wbuf_ofs += c->wbuf_pagesize;
	else
		c->wbuf_ofs = 0xffffffff;
	c->wbuf_len = 0;
	return 0;
}

/* Trigger garbage collection to flush the write-buffer.
   If ino arg is zero, do it if _any_ real (i.e. not GC) writes are
   outstanding. If ino arg non-zero, do it only if a write for the
   given inode is outstanding. */
int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino)
{
	uint32_t old_wbuf_ofs;
	uint32_t old_wbuf_len;
	int ret = 0;

	D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() called for ino #%u...\n", ino));

	if (!c->wbuf)
		return 0;

	down(&c->alloc_sem);
	if (!jffs2_wbuf_pending_for_ino(c, ino)) {
		D1(printk(KERN_DEBUG "Ino #%d not pending in wbuf. Returning\n", ino));
		up(&c->alloc_sem);
		return 0;
	}

	old_wbuf_ofs = c->wbuf_ofs;
	old_wbuf_len = c->wbuf_len;

	if (c->unchecked_size) {
		/* GC won't make any progress for a while */
		D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() padding. Not finished checking\n"));
		down_write(&c->wbuf_sem);
		ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
		/* retry flushing wbuf in case jffs2_wbuf_recover
		   left some data in the wbuf */
		if (ret)
			ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
		up_write(&c->wbuf_sem);
	} else while (old_wbuf_len &&
		      old_wbuf_ofs == c->wbuf_ofs) {

		up(&c->alloc_sem);

		D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() calls gc pass\n"));

		ret = jffs2_garbage_collect_pass(c);
		if (ret) {
			/* GC failed. Flush it with padding instead */
			down(&c->alloc_sem);
			down_write(&c->wbuf_sem);
			ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
			/* retry flushing wbuf in case jffs2_wbuf_recover
			   left some data in the wbuf */
			if (ret)
				ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
			up_write(&c->wbuf_sem);
			break;
		}
		down(&c->alloc_sem);
	}

	D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() ends...\n"));

	up(&c->alloc_sem);
	return ret;
}

/* Pad write-buffer to end and write it, wasting space. */
int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c)
{
	int ret;

	if (!c->wbuf)
		return 0;

	down_write(&c->wbuf_sem);
	ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
	/* retry - maybe wbuf recover left some data in wbuf. */
	if (ret)
		ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
	up_write(&c->wbuf_sem);

	return ret;
}

static size_t jffs2_fill_wbuf(struct jffs2_sb_info *c, const uint8_t *buf,
			      size_t len)
{
	if (len && !c->wbuf_len && (len >= c->wbuf_pagesize))
		return 0;

	if (len > (c->wbuf_pagesize - c->wbuf_len))
		len = c->wbuf_pagesize - c->wbuf_len;
	memcpy(c->wbuf + c->wbuf_len, buf, len);
	c->wbuf_len += (uint32_t) len;
	return len;
}

int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs,
		       unsigned long count, loff_t to, size_t *retlen,
		       uint32_t ino)
{
	struct jffs2_eraseblock *jeb;
	size_t wbuf_retlen, donelen = 0;
	uint32_t outvec_to = to;
	int ret, invec;

	/* If not writebuffered flash, don't bother */
	if (!jffs2_is_writebuffered(c))
		return jffs2_flash_direct_writev(c, invecs, count, to, retlen);

	down_write(&c->wbuf_sem);

	/* If wbuf_ofs is not initialized, set it to target address */
	if (c->wbuf_ofs == 0xFFFFFFFF) {
		c->wbuf_ofs = PAGE_DIV(to);
		c->wbuf_len = PAGE_MOD(to);
		memset(c->wbuf,0xff,c->wbuf_pagesize);
	}

	/*
	 * Sanity checks on target address.  It's permitted to write
	 * at PAD(c->wbuf_len+c->wbuf_ofs), and it's permitted to
	 * write at the beginning of a new erase block. Anything else,
	 * and you die.  New block starts at xxx000c (0-b = block
	 * header)
	 */
	if (SECTOR_ADDR(to) != SECTOR_ADDR(c->wbuf_ofs)) {
		/* It's a write to a new block */
		if (c->wbuf_len) {
			D1(printk(KERN_DEBUG "jffs2_flash_writev() to 0x%lx "
				  "causes flush of wbuf at 0x%08x\n",
				  (unsigned long)to, c->wbuf_ofs));
			ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
			if (ret)
				goto outerr;
		}
		/* set pointer to new block */
		c->wbuf_ofs = PAGE_DIV(to);
		c->wbuf_len = PAGE_MOD(to);
	}

	if (to != PAD(c->wbuf_ofs + c->wbuf_len)) {
		/* We're not writing immediately after the writebuffer. Bad. */
		printk(KERN_CRIT "jffs2_flash_writev(): Non-contiguous write "
		       "to %08lx\n", (unsigned long)to);
		if (c->wbuf_len)
			printk(KERN_CRIT "wbuf was previously %08x-%08x\n",
			       c->wbuf_ofs, c->wbuf_ofs+c->wbuf_len);
		BUG();
	}

	/* adjust alignment offset */
	if (c->wbuf_len != PAGE_MOD(to)) {
		c->wbuf_len = PAGE_MOD(to);
		/* take care of alignment to next page */
		if (!c->wbuf_len) {
			c->wbuf_len = c->wbuf_pagesize;
			ret = __jffs2_flush_wbuf(c, NOPAD);
			if (ret)
				goto outerr;
		}
	}

	for (invec = 0; invec < count; invec++) {
		int vlen = invecs[invec].iov_len;
		uint8_t *v = invecs[invec].iov_base;

		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;
		}
		vlen -= wbuf_retlen;