ext4_blockdev: a number of changes below
[lwext4.git] / lwext4 / ext4_blockdev.c
index 56b4c34fd61df867ab474cb4e88b6da919b2763b..3fb9368628a747a0dc24c3e5337bb7262ec1975d 100644 (file)
 
 int ext4_block_init(struct ext4_blockdev *bdev)
 {
-    int rc;
-    ext4_assert(bdev);
+       int rc;
+       ext4_assert(bdev);
 
-    ext4_assert(bdev->open && bdev->close && bdev->bread && bdev->bwrite);
+       ext4_assert(bdev->open && bdev->close && bdev->bread && bdev->bwrite);
 
-    /*Low level block init*/
-    rc = bdev->open(bdev);
-    if (rc != EOK)
-        return rc;
+       /*Low level block init*/
+       rc = bdev->open(bdev);
+       if (rc != EOK)
+               return rc;
 
-    bdev->flags |= EXT4_BDEV_INITIALIZED;
+       bdev->flags |= EXT4_BDEV_INITIALIZED;
 
-    return EOK;
+       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));
+       /*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;
+       bdev->lg_bsize = lb_bsize;
+       bdev->lg_bcnt = (bdev->ph_bcnt * bdev->ph_bsize) / lb_bsize;
 }
 
 int ext4_block_fini(struct ext4_blockdev *bdev)
 {
-    ext4_assert(bdev);
+       ext4_assert(bdev);
 
-    bdev->flags &= ~(EXT4_BDEV_INITIALIZED);
+       bdev->flags &= ~(EXT4_BDEV_INITIALIZED);
 
-    /*Low level block fini*/
-    return bdev->close(bdev);
+       /*Low level block fini*/
+       return bdev->close(bdev);
+}
+
+int ext4_block_flush_buf(struct ext4_blockdev *bdev, struct ext4_buf *buf)
+{
+       int r;
+       struct ext4_bcache *bc = bdev->bc;
+       /*Only flushing unreferenced buffer is allowed.*/
+       ext4_assert(!buf->refctr);
+
+       if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
+               r = ext4_blocks_set_direct(bdev, buf->data, buf->lba, 1);
+
+               if (r) {
+                       if (buf->end_write)
+                               buf->end_write(bc, buf, r, buf->end_write_arg);
+
+                       return r;
+               }
+
+               ext4_bcache_remove_dirty_node(bc, buf);
+               ext4_bcache_clear_flag(buf, BC_DIRTY);
+               if (buf->end_write)
+                       buf->end_write(bc, buf, r, buf->end_write_arg);
+
+       }
+       return EOK;
+}
+
+int ext4_block_cache_shake(struct ext4_blockdev *bdev)
+{
+       struct ext4_buf *buf;
+       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)) {
+                       int r = ext4_block_flush_buf(bdev, buf);
+                       if (r != EOK)
+                               return r;
+
+               }
+
+               ext4_bcache_drop_buf(bdev->bc, buf);
+       }
+       return EOK;
+}
+
+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);
+
+       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 and) drop it anyway :(*/
+       r = ext4_block_cache_shake(bdev);
+       if (r != EOK)
+               return r;
+
+       r = ext4_bcache_alloc(bdev->bc, b, &is_new);
+       if (r != EOK)
+               return r;
+
+       if (!b->data)
+               return ENOMEM;
+
+       return EOK;
 }
 
 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
-                   uint64_t lba)
+                  uint64_t lba)
 {
-    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;
-            }
-        }
-
-        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;
-
-            /*No delayed anymore*/
-            bdev->bc->free_delay[free_candidate] = 0;
-
-            /*Reduce reference counter*/
-            bdev->bc->ref_blocks--;
-        }
-    }
-
-    r = ext4_bcache_alloc(bdev->bc, b, &is_new);
-    if (r != EOK)
-        return r;
-
-    if (!is_new) {
-        /*Block is in cache. Read from physical device is not required*/
-        return EOK;
-    }
-
-    if (!b->data)
-        return ENOMEM;
-
-    pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
-    pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
-
-    r = bdev->bread(bdev, b->data, pba, pb_cnt);
-
-    if (r != EOK) {
-        ext4_bcache_free(bdev->bc, b, 0);
-        b->lb_id = 0;
-        return r;
-    }
-
-    bdev->bread_ctr++;
-    return EOK;
+       int r = ext4_block_get_noread(bdev, b, lba);
+       if (r != EOK)
+               return r;
+
+       if (b->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);
+       b->uptodate = true;
+       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;
-
-    /*No 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) {
-
-        /*Free cache block and mark as free delayed*/
-        return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
-    }
-
-    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;
+       ext4_assert(bdev && b);
+       ext4_assert(b->buf);
+
+       if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
+               return EIO;
+
+       return ext4_bcache_free(bdev->bc, b);
 }
 
 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
-                           uint32_t cnt)
+                          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->ph_bsize;
+       pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 
-    bdev->bread_ctr++;
-    return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
+       bdev->bread_ctr++;
+       return bdev->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->ph_bsize;
+       pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 
-    bdev->bwrite_ctr++;
+       bdev->bwrite_ctr++;
 
-    return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
+       return bdev->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;
+       uint64_t block_end;
+       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->flags & EXT4_BDEV_INITIALIZED))
+               return EIO;
 
-    if (!(block_end < bdev->ph_bcnt))
-        return EINVAL; /*Ups. Out of range operation*/
+       block_idx = off / bdev->ph_bsize;
+       block_end = block_idx + len / bdev->ph_bsize;
 
-    /*OK lets deal with the first possible unaligned block*/
-    unalg = (off & (bdev->ph_bsize - 1));
-    if (unalg) {
+       if (!(block_end < bdev->ph_bcnt))
+               return EINVAL; /*Ups. Out of range operation*/
 
-        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->ph_bsize - 1));
+       if (unalg) {
 
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+               uint32_t wlen = (bdev->ph_bsize - unalg) > len
+                                   ? len
+                                   : (bdev->ph_bsize - unalg);
 
-        if (r != EOK)
-            return r;
+               r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+               if (r != EOK)
+                       return r;
 
-        memcpy(bdev->ph_bbuf + unalg, p, wlen);
+               memcpy(bdev->ph_bbuf + unalg, p, wlen);
 
-        r = bdev->bwrite(bdev, bdev->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->ph_bsize;
-    r = bdev->bwrite(bdev, p, block_idx, blen);
+       /*Aligned data*/
+       blen = len / bdev->ph_bsize;
+       r = bdev->bwrite(bdev, p, block_idx, blen);
+       if (r != EOK)
+               return r;
 
-    if (r != EOK)
-        return r;
+       p += bdev->ph_bsize * blen;
+       len -= bdev->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 = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+               if (r != EOK)
+                       return r;
 
-    /*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);
 
-        memcpy(bdev->ph_bbuf, p, len);
+               r = bdev->bwrite(bdev, bdev->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;
-    }
-
-    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;
+       uint64_t block_end;
+       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->flags & EXT4_BDEV_INITIALIZED))
+               return EIO;
 
-    block_idx = off / bdev->ph_bsize;
-    block_end = block_idx + len / bdev->ph_bsize;
+       block_idx = off / bdev->ph_bsize;
+       block_end = block_idx + len / bdev->ph_bsize;
 
-    if (!(block_end < bdev->ph_bcnt))
-        return EINVAL; /*Ups. Out of range operation*/
+       if (!(block_end < bdev->ph_bcnt))
+               return EINVAL; /*Ups. Out of range operation*/
 
-    /*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->ph_bsize - 1));
+       if (unalg) {
 
-        uint32_t rlen =
-            (bdev->ph_bsize - unalg) > len ? len : (bdev->ph_bsize - unalg);
+               uint32_t rlen = (bdev->ph_bsize - unalg) > len
+                                   ? len
+                                   : (bdev->ph_bsize - unalg);
 
-        r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
-        if (r != EOK)
-            return r;
+               r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+               if (r != EOK)
+                       return r;
 
-        memcpy(p, bdev->ph_bbuf + unalg, rlen);
+               memcpy(p, bdev->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->ph_bsize;
 
-    r = bdev->bread(bdev, p, block_idx, blen);
+       r = bdev->bread(bdev, p, block_idx, blen);
+       if (r != EOK)
+               return r;
 
-    if (r != EOK)
-        return r;
+       p += bdev->ph_bsize * blen;
+       len -= bdev->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 = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
+               if (r != EOK)
+                       return r;
 
-    /*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);
+       }
 
-        memcpy(p, bdev->ph_bbuf, len);
-    }
-
-    return r;
+       return r;
 }
 
 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 reference counter*/
-            bdev->bc->ref_blocks--;
-        }
-    }
-    return EOK;
+       int r;
+       struct ext4_buf *buf;
+
+       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 all delayed cache blocks*/
+       while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
+               
+               buf = SLIST_FIRST(&bdev->bc->dirty_list);
+               ext4_assert(buf);
+               r = ext4_block_flush_buf(bdev, buf);
+               if (r != EOK)
+                       return r;
+
+       }
+       return EOK;
 }
 
 /**