static int do_cached_write (struct ubiblk_dev *ubiblk, unsigned long sector,
int len, const char *buf)
{
struct ubi_volume_desc *uv = ubiblk->uv;
int ppb = uv->vol->ubi->leb_size / uv->vol->ubi->min_io_size;
unsigned short sectors_per_page = uv->vol->ubi->min_io_size >> 9;
unsigned short page_shift = ffs(uv->vol->ubi->min_io_size) - 1;
unsigned short virt_block, page, page_offset;
unsigned long virt_page;
virt_page = sector / sectors_per_page;
page_offset = sector % sectors_per_page;
virt_block = virt_page / ppb;
page = virt_page % ppb;
if(ubi_is_mapped(uv, virt_block ) == UNMAPPED ){
mutex_lock(&ubiblk->cache_mutex);
ubiblk_flush_writecache(ubiblk);
mutex_unlock(&ubiblk->cache_mutex);
ubiblk_setup_writecache(ubiblk, virt_block);
ubi_leb_map(uv, virt_block, UBI_UNKNOWN);
} else {
if ( STATE_USED == ubiblk->write_cache_state ) {
if ( ubiblk->vbw != virt_block) {
// Commit before we start a new cache.
mutex_lock(&ubiblk->cache_mutex);
ubiblk_flush_writecache(ubiblk);
mutex_unlock(&ubiblk->cache_mutex);
ubiblk_setup_writecache(ubiblk, virt_block);
ubi_leb_unmap(uv, virt_block);
ubi_leb_map(uv, virt_block, UBI_UNKNOWN);
} else {
//dprintk("cache hit: 0x%x\n", virt_page);
}
} else {
// printk("with existing mapping\n");
ubiblk_setup_writecache(ubiblk, virt_block);
ubi_leb_unmap(uv, virt_block);
ubi_leb_map(uv, virt_block, UBI_UNKNOWN);
}
}
memcpy(&ubiblk->write_cache[(page<<page_shift) +(page_offset<<9)],
buf,len);
return 0;
}
int ubifs_leb_map(struct ubifs_info *c, int lnum)
{
int err;
ubifs_assert(!c->ro_media && !c->ro_mount);
if (c->ro_error)
return -EROFS;
if (!dbg_is_tst_rcvry(c))
err = ubi_leb_map(c->ubi, lnum);
else
err = dbg_leb_map(c, lnum);
if (err) {
ubifs_err("mapping LEB %d failed, error %d", lnum, err);
ubifs_ro_mode(c, err);
dbg_dump_stack();
}
return err;
}
/**
* 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 = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM);
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, UBI_SHORTTERM);
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:
if (err != -EAGAIN)
ubifs_ro_mode(c, err);
mutex_unlock(&c->log_mutex);
kfree(ref);
kfree(bud);
return err;
}
