示例#1
0
/**
 * ubifs_log_post_commit - things to do after commit is completed.
 * @c: UBIFS file-system description object
 * @old_ltail_lnum: old log tail LEB number
 *
 * Release buds only after commit is completed, because they must be unchanged
 * if recovery is needed.
 *
 * Unmap log LEBs only after commit is completed, because they may be needed for
 * recovery.
 *
 * This function returns %0 on success and a negative error code on failure.
 */
int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
{
	int lnum, err = 0;

	while (!list_empty(&c->old_buds)) {
		struct ubifs_bud *bud;

		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
		err = ubifs_return_leb(c, bud->lnum);
		if (err)
			return err;
		list_del(&bud->list);
		kfree(bud);
	}
	mutex_lock(&c->log_mutex);
	for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
	     lnum = ubifs_next_log_lnum(c, lnum)) {
		dbg_log("unmap log LEB %d", lnum);
		err = ubifs_leb_unmap(c, lnum);
		if (err)
			goto out;
	}
out:
	mutex_unlock(&c->log_mutex);
	return err;
}
示例#2
0
/**
 * switch_gc_head - switch the garbage collection journal head.
 * @c: UBIFS file-system description object
 * @buf: buffer to write
 * @len: length of the buffer to write
 * @lnum: LEB number written is returned here
 * @offs: offset written is returned here
 *
 * This function switch the GC head to the next LEB which is reserved in
 * @c->gc_lnum. Returns %0 in case of success, %-EAGAIN if commit is required,
 * and other negative error code in case of failures.
 */
static int switch_gc_head(struct ubifs_info *c)
{
	int err, gc_lnum = c->gc_lnum;
	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;

	ubifs_assert(gc_lnum != -1);
	dbg_gc("switch GC head from LEB %d:%d to LEB %d (waste %d bytes)",
	       wbuf->lnum, wbuf->offs + wbuf->used, gc_lnum,
	       c->leb_size - wbuf->offs - wbuf->used);

	err = ubifs_wbuf_sync_nolock(wbuf);
	if (err)
		return err;

	/*
	 * The GC write-buffer was synchronized, we may safely unmap
	 * 'c->gc_lnum'.
	 */
	err = ubifs_leb_unmap(c, gc_lnum);
	if (err)
		return err;

	err = ubifs_wbuf_sync_nolock(wbuf);
	if (err)
		return err;

	err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0);
	if (err)
		return err;

	c->gc_lnum = -1;
	err = ubifs_wbuf_seek_nolock(wbuf, gc_lnum, 0, UBI_LONGTERM);
	return err;
}
示例#3
0
文件: sb.c 项目: ashang/xpenology-3.x
/**
 * fixup_leb - fixup/unmap an LEB containing free space.
 * @c: UBIFS file-system description object
 * @lnum: the LEB number to fix up
 * @len: number of used bytes in LEB (starting at offset 0)
 *
 * This function reads the contents of the given LEB number @lnum, then fixes
 * it up, so that empty min. I/O units in the end of LEB are actually erased on
 * flash (rather than being just all-0xff real data). If the LEB is completely
 * empty, it is simply unmapped.
 */
static int fixup_leb(struct ubifs_info *c, int lnum, int len)
{
	int err;

	ubifs_assert(len >= 0);
	ubifs_assert(len % c->min_io_size == 0);
	ubifs_assert(len < c->leb_size);

	if (len == 0) {
		dbg_mnt("unmap empty LEB %d", lnum);
		return ubifs_leb_unmap(c, lnum);
	}

	dbg_mnt("fixup LEB %d, data len %d", lnum, len);
	err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
	if (err)
		return err;

	return ubifs_leb_change(c, lnum, c->sbuf, len);
}
示例#4
0
/**
 * ubifs_log_start_commit - start commit.
 * @c: UBIFS file-system description object
 * @ltail_lnum: return new log tail LEB number
 *
 * The commit operation starts with writing "commit start" node to the log and
 * reference nodes for all journal heads which will define new journal after
 * the commit has been finished. The commit start and reference nodes are
 * written in one go to the nearest empty log LEB (hence, when commit is
 * finished UBIFS may safely unmap all the previous log LEBs). This function
 * returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
{
	void *buf;
	struct ubifs_cs_node *cs;
	struct ubifs_ref_node *ref;
	int err, i, max_len, len;

	err = dbg_check_bud_bytes(c);
	if (err)
		return err;

	max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
	max_len = ALIGN(max_len, c->min_io_size);
	buf = cs = kmalloc(max_len, GFP_NOFS);
	if (!buf)
		return -ENOMEM;

	cs->ch.node_type = UBIFS_CS_NODE;
	cs->cmt_no = cpu_to_le64(c->cmt_no);
	ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);

	/*
	 * Note, we do not lock 'c->log_mutex' because this is the commit start
	 * phase and we are exclusively using the log. And we do not lock
	 * write-buffer because nobody can write to the file-system at this
	 * phase.
	 */

	len = UBIFS_CS_NODE_SZ;
	for (i = 0; i < c->jhead_cnt; i++) {
		int lnum = c->jheads[i].wbuf.lnum;
		int offs = c->jheads[i].wbuf.offs;

		if (lnum == -1 || offs == c->leb_size)
			continue;

		dbg_log("add ref to LEB %d:%d for jhead %s",
			lnum, offs, dbg_jhead(i));
		ref = buf + len;
		ref->ch.node_type = UBIFS_REF_NODE;
		ref->lnum = cpu_to_le32(lnum);
		ref->offs = cpu_to_le32(offs);
		ref->jhead = cpu_to_le32(i);

		ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
		len += UBIFS_REF_NODE_SZ;
	}

	ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);

#ifdef CONFIG_UBIFS_FS_FULL_USE_LOG
	/* Not Switch to next log LEB, programming next available page in the same log LEB continuously*/

	/* if available page is in the end of the LEB, switch to next LEB*/
	if(c->lhead_offs >= (c->leb_size - (c->min_io_size * 4)) )
	{
		int old_lnum = c->lhead_lnum;
		int old_offs = c->lhead_offs;
		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
		c->lhead_offs = 0;
		ubifs_msg("switch log LEB %d:%d to %d:%d\n", old_lnum, old_offs, c->lhead_lnum, c->lhead_offs);
	}
#else
	/* Switch to the next log LEB */
	if (c->lhead_offs) {
		int old_lnum = c->lhead_lnum;
		int old_offs = c->lhead_offs;
		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
		c->lhead_offs = 0;
		ubifs_msg("switch log LEB %d:%d to %d:%d\n", old_lnum, old_offs, c->lhead_lnum, c->lhead_offs);
	}
#endif

	if (c->lhead_offs == 0) {
		/* Must ensure next LEB has been unmapped */
		err = ubifs_leb_unmap(c, c->lhead_lnum);
		if (err)
			goto out;
	}

	len = ALIGN(len, c->min_io_size);
	dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
	err = ubifs_leb_write(c, c->lhead_lnum, cs, c->lhead_offs, len); //MTK, modify offset 0 -> c->lhead_offs
	if (err)
		goto out;

	*ltail_lnum = c->lhead_lnum;

	c->lhead_offs += len;
	if (c->lhead_offs == c->leb_size) {
		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
		c->lhead_offs = 0;
	}

	remove_buds(c);

	/*
	 * We have started the commit and now users may use the rest of the log
	 * for new writes.
	 */
	c->min_log_bytes = 0;

out:
	kfree(buf);
	return err;
}
示例#5
0
/**
 * ubifs_add_bud_to_log - add a new bud to the log.
 * @c: UBIFS file-system description object
 * @jhead: journal head the bud belongs to
 * @lnum: LEB number of the bud
 * @offs: starting offset of the bud
 *
 * This function writes reference node for the new bud LEB @lnum it to the log,
 * and adds it to the buds tress. It also makes sure that log size does not
 * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
 * %-EAGAIN if commit is required, and a negative error codes in case of
 * failure.
 */
int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
{
	int err;
	struct ubifs_bud *bud;
	struct ubifs_ref_node *ref;

	bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
	if (!bud)
		return -ENOMEM;
	ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
	if (!ref) {
		kfree(bud);
		return -ENOMEM;
	}

	mutex_lock(&c->log_mutex);
	ubifs_assert(!c->ro_media && !c->ro_mount);
	if (c->ro_error) {
		err = -EROFS;
		goto out_unlock;
	}

	/* Make sure we have enough space in the log */
	if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
		dbg_log("not enough log space - %lld, required %d",
			empty_log_bytes(c), c->min_log_bytes);
		ubifs_commit_required(c);
		err = -EAGAIN;
		goto out_unlock;
	}

	/*
	 * Make sure the amount of space in buds will not exceed the
	 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
	 * limits.
	 *
	 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
	 * because we are holding @c->log_mutex. All @c->bud_bytes take place
	 * when both @c->log_mutex and @c->bud_bytes are locked.
	 */
	if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
		dbg_log("bud bytes %lld (%lld max), require commit",
			c->bud_bytes, c->max_bud_bytes);
		ubifs_commit_required(c);
		err = -EAGAIN;
		goto out_unlock;
	}

	/*
	 * If the journal is full enough - start background commit. Note, it is
	 * OK to read 'c->cmt_state' without spinlock because integer reads
	 * are atomic in the kernel.
	 */
	if (c->bud_bytes >= c->bg_bud_bytes &&
	    c->cmt_state == COMMIT_RESTING) {
		dbg_log("bud bytes %lld (%lld max), initiate BG commit",
			c->bud_bytes, c->max_bud_bytes);
		ubifs_request_bg_commit(c);
	}

	bud->lnum = lnum;
	bud->start = offs;
	bud->jhead = jhead;

	ref->ch.node_type = UBIFS_REF_NODE;
	ref->lnum = cpu_to_le32(bud->lnum);
	ref->offs = cpu_to_le32(bud->start);
	ref->jhead = cpu_to_le32(jhead);

	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
		c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
		c->lhead_offs = 0;
	}

	if (c->lhead_offs == 0) {
		/* Must ensure next log LEB has been unmapped */
		err = ubifs_leb_unmap(c, c->lhead_lnum);
		if (err)
			goto out_unlock;
	}

	if (bud->start == 0) {
		/*
		 * Before writing the LEB reference which refers an empty LEB
		 * to the log, we have to make sure it is mapped, because
		 * otherwise we'd risk to refer an LEB with garbage in case of
		 * an unclean reboot, because the target LEB might have been
		 * unmapped, but not yet physically erased.
		 */
		err = ubifs_leb_map(c, bud->lnum);
		if (err)
			goto out_unlock;
	}

	dbg_log("write ref LEB %d:%d",
		c->lhead_lnum, c->lhead_offs);
	err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
			       c->lhead_offs);
	if (err)
		goto out_unlock;

	c->lhead_offs += c->ref_node_alsz;

	ubifs_add_bud(c, bud);

	mutex_unlock(&c->log_mutex);
	kfree(ref);
	return 0;

out_unlock:
	mutex_unlock(&c->log_mutex);
	kfree(ref);
	kfree(bud);
	return err;
}