X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=lwext4%2Fext4_blockdev.c;h=23ad9ee3467368699090a6c921ad5186a3c17cab;hb=e1bbe336d1736703a6b1565cfa5565fb276643a1;hp=c83015b6b51895faf4edc1b64a4b7cde476bbe0b;hpb=d812bca336c8d67a5b1a9744b36c0ecbb5baa8b3;p=lwext4.git

diff --git a/lwext4/ext4_blockdev.c b/lwext4/ext4_blockdev.c
index c83015b..23ad9ee 100644
--- a/lwext4/ext4_blockdev.c
+++ b/lwext4/ext4_blockdev.c
@@ -34,412 +34,430 @@
  * @brief Block device module.
  */
 
-#include <ext4_config.h>
-#include <ext4_blockdev.h>
-#include <ext4_errno.h>
-#include <ext4_debug.h>
+#include "ext4_config.h"
+#include "ext4_blockdev.h"
+#include "ext4_errno.h"
+#include "ext4_debug.h"
 
 #include <string.h>
 #include <stdlib.h>
 
+static void ext4_bdif_lock(struct ext4_blockdev *bdev)
+{
+	if (!bdev->bdif->lock)
+		return;
 
+	int r = bdev->bdif->lock(bdev);
+	ext4_assert(r == EOK);
+}
 
-int ext4_block_init(struct ext4_blockdev *bdev)
+static void ext4_bdif_unlock(struct ext4_blockdev *bdev)
 {
-    int rc;
-    ext4_assert(bdev);
+	if (!bdev->bdif->unlock)
+		return;
 
-    ext4_assert(bdev->open && bdev->close && bdev->bread  && bdev->bwrite);
+	int r = bdev->bdif->unlock(bdev);
+	ext4_assert(r == EOK);
+}
 
-    /*Low level block init*/
-    rc = bdev->open(bdev);
-    if(rc != EOK)
-        return rc;
+static int ext4_bdif_bread(struct ext4_blockdev *bdev, void *buf,
+			   uint64_t blk_id, uint32_t blk_cnt)
+{
+	ext4_bdif_lock(bdev);
+	int r = bdev->bdif->bread(bdev, buf, blk_id, blk_cnt);
+	bdev->bdif->bread_ctr++;
+	ext4_bdif_unlock(bdev);
+	return r;
+}
 
-    bdev->flags |= EXT4_BDEV_INITIALIZED;
+static int ext4_bdif_bwrite(struct ext4_blockdev *bdev, const void *buf,
+			    uint64_t blk_id, uint32_t blk_cnt)
+{
+	ext4_bdif_lock(bdev);
+	int r = bdev->bdif->bwrite(bdev, buf, blk_id, blk_cnt);
+	bdev->bdif->bwrite_ctr++;
+	ext4_bdif_unlock(bdev);
+	return r;
+}
 
-    return EOK;
+int ext4_block_init(struct ext4_blockdev *bdev)
+{
+	int rc;
+	ext4_assert(bdev);
+	ext4_assert(bdev->bdif);
+	ext4_assert(bdev->bdif->open &&
+		   bdev->bdif->close &&
+		   bdev->bdif->bread &&
+		   bdev->bdif->bwrite);
+
+	if (bdev->bdif->ph_refctr) {
+		bdev->bdif->ph_refctr++;
+		return EOK;
+	}
+
+	/*Low level block init*/
+	rc = bdev->bdif->open(bdev);
+	if (rc != EOK)
+		return rc;
+
+	bdev->bdif->ph_refctr = 1;
+	return EOK;
 }
 
 int ext4_block_bind_bcache(struct ext4_blockdev *bdev, struct ext4_bcache *bc)
 {
-    ext4_assert(bdev && bc);
-    bdev->bc = bc;
-    return EOK;
+	ext4_assert(bdev && bc);
+	bdev->bc = bc;
+	bc->bdev = bdev;
+	return EOK;
 }
 
 void ext4_block_set_lb_size(struct ext4_blockdev *bdev, uint64_t lb_bsize)
 {
-    /*Logical block size has to be multiply of physical */
-    ext4_assert(!(lb_bsize % bdev->ph_bsize));
-
-    bdev->lg_bsize = lb_bsize;
-    bdev->lg_bcnt = (bdev->ph_bcnt * bdev->ph_bsize) / lb_bsize;
+	/*Logical block size has to be multiply of physical */
+	ext4_assert(!(lb_bsize % bdev->bdif->ph_bsize));
 
+	bdev->lg_bsize = lb_bsize;
+	bdev->lg_bcnt = bdev->part_size / lb_bsize;
 }
 
 int ext4_block_fini(struct ext4_blockdev *bdev)
 {
-    ext4_assert(bdev);
+	ext4_assert(bdev);
 
-    bdev->flags &= ~(EXT4_BDEV_INITIALIZED);
+	if (!bdev->bdif->ph_refctr)
+		return EOK;
 
-    /*Low level block fini*/
-    return bdev->close(bdev);
-}
+	bdev->bdif->ph_refctr--;
+	if (bdev->bdif->ph_refctr)
+		return EOK;
 
+	/*Low level block fini*/
+	return bdev->bdif->close(bdev);
+}
 
-int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
-    uint64_t lba)
+int ext4_block_flush_buf(struct ext4_blockdev *bdev, struct ext4_buf *buf)
 {
-    uint64_t pba;
-    uint32_t pb_cnt;
-    uint32_t i;
-    bool is_new;
-    int r;
-
-    ext4_assert(bdev && b);
-
-    if(!(bdev->flags & EXT4_BDEV_INITIALIZED))
-        return EIO;
-
-    if(!(lba < bdev->lg_bcnt))
-        return ERANGE;
-
-    b->dirty = 0;
-    b->lb_id = lba;
-
-    /*If cache is full we have to flush it anyway :(*/
-    if(ext4_bcache_is_full(bdev->bc) && bdev->cache_write_back){
-
-        uint32_t free_candidate = bdev->bc->cnt;
-        uint32_t min_lru = 0xFFFFFFFF;
-
-        for (i = 0; i < bdev->bc->cnt; ++i) {
-            /*Check if buffer free was delayed.*/
-            if(!bdev->bc->free_delay[i])
-                continue;
-
-            /*Check reference counter.*/
-            if(bdev->bc->refctr[i])
-                continue;
-
-            if(bdev->bc->lru_id[i] < min_lru){
-                min_lru = bdev->bc->lru_id[i];
-                free_candidate = i;
-                continue;
-            }
-        }
+	int r;
+	struct ext4_bcache *bc = bdev->bc;
+
+	if (ext4_bcache_test_flag(buf, BC_DIRTY) &&
+	    ext4_bcache_test_flag(buf, BC_UPTODATE)) {
+		r = ext4_blocks_set_direct(bdev, buf->data, buf->lba, 1);
+		if (r) {
+			if (buf->end_write) {
+				bc->dont_shake = true;
+				buf->end_write(bc, buf, r, buf->end_write_arg);
+				bc->dont_shake = false;
+			}
+
+			return r;
+		}
+
+		ext4_bcache_remove_dirty_node(bc, buf);
+		ext4_bcache_clear_flag(buf, BC_DIRTY);
+		if (buf->end_write) {
+			bc->dont_shake = true;
+			buf->end_write(bc, buf, r, buf->end_write_arg);
+			bc->dont_shake = false;
+		}
+	}
+	return EOK;
+}
 
-        if(free_candidate < bdev->bc->cnt){
-            /*Buffer free was delayed and have no reference. Flush it.*/
-            r = ext4_blocks_set_direct(bdev,
-                    bdev->bc->data + bdev->bc->itemsize * free_candidate,
-                    bdev->bc->lba[free_candidate], 1);
-            if(r != EOK)
-                return r;
+int ext4_block_flush_lba(struct ext4_blockdev *bdev, uint64_t lba)
+{
+	int r = EOK;
+	struct ext4_buf *buf;
+	struct ext4_block b;
+	buf = ext4_bcache_find_get(bdev->bc, &b, lba);
+	if (buf) {
+		r = ext4_block_flush_buf(bdev, buf);
+		ext4_bcache_free(bdev->bc, &b);
+	}
+	return r;
+}
 
-            /*No delayed anymore*/
-            bdev->bc->free_delay[free_candidate] = 0;
+int ext4_block_cache_shake(struct ext4_blockdev *bdev)
+{
+	int r = EOK;
+	struct ext4_buf *buf;
+	if (bdev->bc->dont_shake)
+		return EOK;
+
+	while (!RB_EMPTY(&bdev->bc->lru_root) &&
+		ext4_bcache_is_full(bdev->bc)) {
+
+		buf = ext4_buf_lowest_lru(bdev->bc);
+		ext4_assert(buf);
+		if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
+			r = ext4_block_flush_buf(bdev, buf);
+			if (r != EOK)
+				break;
+
+		}
+
+		ext4_bcache_drop_buf(bdev->bc, buf);
+	}
+	return r;
+}
 
-            /*Reduce refered block count*/
-            bdev->bc->ref_blocks--;
-        }
-    }
+int ext4_block_get_noread(struct ext4_blockdev *bdev, struct ext4_block *b,
+			  uint64_t lba)
+{
+	bool is_new;
+	int r;
 
+	ext4_assert(bdev && b);
 
-    r = ext4_bcache_alloc(bdev->bc, b, &is_new);
-    if(r != EOK)
-        return r;
+	if (!bdev->bdif->ph_refctr)
+		return EIO;
 
+	if (!(lba < bdev->lg_bcnt))
+		return ERANGE;
 
-    if(!is_new){
-        /*Block is in cache. Read from physical device is not required*/
-        return EOK;
-    }
+	b->lb_id = lba;
 
-    if(!b->data)
-        return ENOMEM;
+	/*If cache is full we have to (flush and) drop it anyway :(*/
+	r = ext4_block_cache_shake(bdev);
+	if (r != EOK)
+		return r;
 
-    pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
-    pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
+	r = ext4_bcache_alloc(bdev->bc, b, &is_new);
+	if (r != EOK)
+		return r;
 
-    r = bdev->bread(bdev, b->data, pba, pb_cnt);
+	if (!b->data)
+		return ENOMEM;
 
-    if(r != EOK){
-        ext4_bcache_free(bdev->bc, b, 0);
-        b->lb_id = 0;
-        return r;
-    }
+	return EOK;
+}
 
-    bdev->bread_ctr++;
-    return EOK;
+int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
+		   uint64_t lba)
+{
+	int r = ext4_block_get_noread(bdev, b, lba);
+	if (r != EOK)
+		return r;
+
+	if (ext4_bcache_test_flag(b->buf, BC_UPTODATE)) {
+		/* Data in the cache is up-to-date.
+		 * Reading from physical device is not required */
+		return EOK;
+	}
+
+	r = ext4_blocks_get_direct(bdev, b->data, lba, 1);
+	if (r != EOK) {
+		ext4_bcache_free(bdev->bc, b);
+		b->lb_id = 0;
+		return r;
+	}
+
+	/* Mark buffer up-to-date, since
+	 * fresh data is read from physical device just now. */
+	ext4_bcache_set_flag(b->buf, BC_UPTODATE);
+	return EOK;
 }
 
 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 {
-    uint64_t pba;
-    uint32_t pb_cnt;
-    int r;
-
-    ext4_assert(bdev && b);
-
-    if(!(bdev->flags & EXT4_BDEV_INITIALIZED))
-        return EIO;
-
-    /*Doesn,t need to write.*/
-    if(!b->dirty && !bdev->bc->dirty[b->cache_id]){
-        ext4_bcache_free(bdev->bc, b, 0);
-        return EOK;
-    }
-
-    /*Free cache delay mode*/
-    if(bdev->cache_write_back){
+	ext4_assert(bdev && b);
+	ext4_assert(b->buf);
 
-        /*Free cahe block and mark as free delayed*/
-        return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
-    }
+	if (!bdev->bdif->ph_refctr)
+		return EIO;
 
-    if(bdev->bc->refctr[b->cache_id] > 1){
-        bdev->bc->dirty[b->cache_id] = true;
-        return ext4_bcache_free(bdev->bc, b, 0);
-    }
-
-
-    pba = (b->lb_id * bdev->lg_bsize) / bdev->ph_bsize;
-    pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
-
-    r = bdev->bwrite(bdev, b->data, pba, pb_cnt);
-    bdev->bc->dirty[b->cache_id] = false;
-    if(r != EOK){
-        b->dirty = false;
-        ext4_bcache_free(bdev->bc, b, 0);
-        return r;
-    }
-
-    bdev->bwrite_ctr++;
-    b->dirty = false;
-    ext4_bcache_free(bdev->bc, b, 0);
-    return EOK;
+	return ext4_bcache_free(bdev->bc, b);
 }
 
-int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf,
-    uint64_t lba, uint32_t cnt)
+int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
+			   uint32_t cnt)
 {
-    uint64_t pba;
-    uint32_t pb_cnt;
+	uint64_t pba;
+	uint32_t pb_cnt;
 
-    ext4_assert(bdev && buf);
+	ext4_assert(bdev && buf);
 
-    pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
-    pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
+	pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
+	pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 
-    bdev->bread_ctr++;
-    return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
+	return ext4_bdif_bread(bdev, buf, pba, pb_cnt * cnt);
 }
 
 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
-    uint64_t lba, uint32_t cnt)
+			   uint64_t lba, uint32_t cnt)
 {
-    uint64_t pba;
-    uint32_t pb_cnt;
+	uint64_t pba;
+	uint32_t pb_cnt;
 
-    ext4_assert(bdev && buf);
+	ext4_assert(bdev && buf);
 
-    pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
-    pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
+	pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
+	pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 
-    bdev->bwrite_ctr++;
-
-    return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
+	return ext4_bdif_bwrite(bdev, buf, pba, pb_cnt * cnt);
 }
 
-
 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
-    const void *buf, uint32_t len)
+			  const void *buf, uint32_t len)
 {
-    uint64_t block_idx;
-    uint64_t block_end;
-    uint32_t blen;
-    uint32_t unalg;
-    int r = EOK;
-
-    const uint8_t *p = (void *)buf;
+	uint64_t block_idx;
+	uint32_t blen;
+	uint32_t unalg;
+	int r = EOK;
 
-    ext4_assert(bdev && buf);
+	const uint8_t *p = (void *)buf;
 
-    if(!(bdev->flags & EXT4_BDEV_INITIALIZED))
-        return EIO;
+	ext4_assert(bdev && buf);
 
-    block_idx =  off / bdev->ph_bsize;
-    block_end   =  block_idx + len / bdev->ph_bsize;
+	if (!bdev->bdif->ph_refctr)
+		return EIO;
 
-    if(!(block_end < bdev->ph_bcnt))
-        return EINVAL;  /*Ups. Out of range operation*/
+	if (off + len > bdev->part_size)
+		return EINVAL; /*Ups. Out of range operation*/
 
-    /*OK lets deal with the first possible unaligned block*/
-    unalg = (off & (bdev->ph_bsize - 1));
-    if(unalg){
+	block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
 
-        uint32_t wlen = (bdev->ph_bsize - unalg) > len ?
-                len : (bdev->ph_bsize - unalg);
+	/*OK lets deal with the first possible unaligned block*/
+	unalg = (off & (bdev->bdif->ph_bsize - 1));
+	if (unalg) {
 
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+		uint32_t wlen = (bdev->bdif->ph_bsize - unalg) > len
+				    ? len
+				    : (bdev->bdif->ph_bsize - unalg);
 
-        if(r != EOK)
-            return r;
+		r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
 
-        memcpy(bdev->ph_bbuf + unalg, p, wlen);
+		memcpy(bdev->bdif->ph_bbuf + unalg, p, wlen);
+		r = ext4_bdif_bwrite(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
 
-        r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
-        if(r != EOK)
-            return r;
+		p += wlen;
+		len -= wlen;
+		block_idx++;
+	}
 
-        p   += wlen;
-        len -= wlen;
-        block_idx++;
-    }
+	/*Aligned data*/
+	blen = len / bdev->bdif->ph_bsize;
+	r = ext4_bdif_bwrite(bdev, p, block_idx, blen);
+	if (r != EOK)
+		return r;
 
+	p += bdev->bdif->ph_bsize * blen;
+	len -= bdev->bdif->ph_bsize * blen;
 
-    /*Aligned data*/
-    blen = len / bdev->ph_bsize;
-    r = bdev->bwrite(bdev, p, block_idx, blen);
+	block_idx += blen;
 
-    if(r != EOK)
-        return r;
+	/*Rest of the data*/
+	if (len) {
+		r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
 
-    p += bdev->ph_bsize * blen;
-    len -= bdev->ph_bsize * blen;
+		memcpy(bdev->bdif->ph_bbuf, p, len);
+		r = ext4_bdif_bwrite(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
+	}
 
-    block_idx += blen;
-
-
-    /*Rest of the data*/
-    if(len){
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
-        if(r != EOK)
-            return r;
-
-        memcpy(bdev->ph_bbuf, p, len);
-
-        r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
-
-        if(r != EOK)
-            return r;
-    }
-
-    return r;
+	return r;
 }
 
-
 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
-    uint32_t len)
+			 uint32_t len)
 {
-    uint64_t block_idx;
-    uint64_t block_end;
-    uint32_t blen;
-    uint32_t unalg;
-    int r = EOK;
+	uint64_t block_idx;
+	uint32_t blen;
+	uint32_t unalg;
+	int r = EOK;
 
-    uint8_t *p = (void *)buf;
+	uint8_t *p = (void *)buf;
 
-    ext4_assert(bdev && buf);
+	ext4_assert(bdev && buf);
 
-    if(!(bdev->flags & EXT4_BDEV_INITIALIZED))
-        return EIO;
+	if (!bdev->bdif->ph_refctr)
+		return EIO;
 
-    block_idx = off / bdev->ph_bsize;
-    block_end = block_idx + len / bdev->ph_bsize;
+	if (off + len > bdev->part_size)
+		return EINVAL; /*Ups. Out of range operation*/
 
-    if(!(block_end < bdev->ph_bcnt))
-        return EINVAL;      /*Ups. Out of range operation*/
+	block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
 
-    /*OK lets deal with the first possible unaligned block*/
-    unalg = (off & (bdev->ph_bsize - 1));
-    if(unalg){
+	/*OK lets deal with the first possible unaligned block*/
+	unalg = (off & (bdev->bdif->ph_bsize - 1));
+	if (unalg) {
 
-        uint32_t rlen = (bdev->ph_bsize - unalg) > len ?
-                len : (bdev->ph_bsize - unalg);
+		uint32_t rlen = (bdev->bdif->ph_bsize - unalg) > len
+				    ? len
+				    : (bdev->bdif->ph_bsize - unalg);
 
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
-        if(r != EOK)
-            return r;
+		r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
 
-        memcpy(p, bdev->ph_bbuf + unalg, rlen);
+		memcpy(p, bdev->bdif->ph_bbuf + unalg, rlen);
 
-        p   += rlen;
-        len -= rlen;
-        block_idx++;
-    }
+		p += rlen;
+		len -= rlen;
+		block_idx++;
+	}
 
-    /*Aligned data*/
-    blen = len / bdev->ph_bsize;
+	/*Aligned data*/
+	blen = len / bdev->bdif->ph_bsize;
 
-    r = bdev->bread(bdev, p, block_idx, blen);
+	r = ext4_bdif_bread(bdev, p, block_idx, blen);
+	if (r != EOK)
+		return r;
 
-    if(r != EOK)
-        return r;
+	p += bdev->bdif->ph_bsize * blen;
+	len -= bdev->bdif->ph_bsize * blen;
 
-    p += bdev->ph_bsize * blen;
-    len -= bdev->ph_bsize * blen;
+	block_idx += blen;
 
-    block_idx += blen;
+	/*Rest of the data*/
+	if (len) {
+		r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
+		if (r != EOK)
+			return r;
 
+		memcpy(p, bdev->bdif->ph_bbuf, len);
+	}
 
-    /*Rest of the data*/
-    if(len){
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
-        if(r != EOK)
-            return r;
-
-        memcpy(p, bdev->ph_bbuf, len);
-    }
+	return r;
+}
 
-    return r;
+int ext4_block_cache_flush(struct ext4_blockdev *bdev)
+{
+	while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
+		int r;
+		struct ext4_buf *buf = SLIST_FIRST(&bdev->bc->dirty_list);
+		ext4_assert(buf);
+		r = ext4_block_flush_buf(bdev, buf);
+		if (r != EOK)
+			return r;
+
+	}
+	return EOK;
 }
 
-int ext4_block_cache_write_back(struct ext4_blockdev *bdev,
-    uint8_t on_off)
+int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 {
-    int r;
-    uint32_t i;
-
-    if(on_off)
-        bdev->cache_write_back++;
-
-    if(!on_off && bdev->cache_write_back)
-        bdev->cache_write_back--;
-
-    /*Flush all delayed cache blocks*/
-    if(!bdev->cache_write_back){
-        for (i = 0; i < bdev->bc->cnt; ++i) {
-
-            /*Check if buffer free was delayed.*/
-            if(!bdev->bc->free_delay[i])
-                continue;
-
-            /*Check reference counter.*/
-            if(bdev->bc->refctr[i])
-                continue;
-
-            /*Buffer free was delayed and have no reference. Flush it.*/
-            r = ext4_blocks_set_direct(bdev,
-                    bdev->bc->data + bdev->bc->itemsize * i,
-                    bdev->bc->lba[i], 1);
-            if(r != EOK)
-                return r;
-
-            /*No delayed anymore*/
-            bdev->bc->free_delay[i] = 0;
-
-            /*Reduce refered block count*/
-            bdev->bc->ref_blocks--;
-        }
-    }
-    return EOK;
+	if (on_off)
+		bdev->cache_write_back++;
+
+	if (!on_off && bdev->cache_write_back)
+		bdev->cache_write_back--;
+
+	if (bdev->cache_write_back)
+		return EOK;
+
+	/*Flush data in all delayed cache blocks*/
+	return ext4_block_cache_flush(bdev);
 }
 
 /**
  * @}
  */
-