/**
* 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;
}
/**
* 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;
}
/**
* 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);
}
/**
* 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;
}
/**
* 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;
}