/**
* create_default_filesystem - format empty UBI volume.
* @c: UBIFS file-system description object
*
* This function creates default empty file-system. Returns zero in case of
* success and a negative error code in case of failure.
*/
static int create_default_filesystem(struct ubifs_info *c)
{
struct ubifs_sb_node *sup;
struct ubifs_mst_node *mst;
struct ubifs_idx_node *idx;
struct ubifs_branch *br;
struct ubifs_ino_node *ino;
struct ubifs_cs_node *cs;
union ubifs_key key;
int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
int min_leb_cnt = UBIFS_MIN_LEB_CNT;
long long tmp64, main_bytes;
__le64 tmp_le64;
/* Some functions called from here depend on the @c->key_len filed */
c->key_len = UBIFS_SK_LEN;
/*
* First of all, we have to calculate default file-system geometry -
* log size, journal size, etc.
*/
if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
/* We can first multiply then divide and have no overflow */
jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
else
jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
jnl_lebs = UBIFS_MIN_JNL_LEBS;
if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
/*
* The log should be large enough to fit reference nodes for all bud
* LEBs. Because buds do not have to start from the beginning of LEBs
* (half of the LEB may contain committed data), the log should
* generally be larger, make it twice as large.
*/
tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
log_lebs = tmp / c->leb_size;
/* Plus one LEB reserved for commit */
log_lebs += 1;
if (c->leb_cnt - min_leb_cnt > 8) {
/* And some extra space to allow writes while committing */
log_lebs += 1;
min_leb_cnt += 1;
}
max_buds = jnl_lebs - log_lebs;
if (max_buds < UBIFS_MIN_BUD_LEBS)
max_buds = UBIFS_MIN_BUD_LEBS;
/*
* Orphan nodes are stored in a separate area. One node can store a lot
* of orphan inode numbers, but when new orphan comes we just add a new
* orphan node. At some point the nodes are consolidated into one
* orphan node.
*/
orph_lebs = UBIFS_MIN_ORPH_LEBS;
#ifdef CONFIG_UBIFS_FS_DEBUG
if (c->leb_cnt - min_leb_cnt > 1)
/*
* For debugging purposes it is better to have at least 2
* orphan LEBs, because the orphan subsystem would need to do
* consolidations and would be stressed more.
*/
orph_lebs += 1;
#endif
main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
main_lebs -= orph_lebs;
lpt_first = UBIFS_LOG_LNUM + log_lebs;
c->lsave_cnt = DEFAULT_LSAVE_CNT;
c->max_leb_cnt = c->leb_cnt;
err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
&big_lpt);
if (err)
return err;
dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
lpt_first + lpt_lebs - 1);
main_first = c->leb_cnt - main_lebs;
/* Create default superblock */
tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
sup = kzalloc(tmp, GFP_KERNEL);
if (!sup)
return -ENOMEM;
tmp64 = (long long)max_buds * c->leb_size;
if (big_lpt)
sup_flags |= UBIFS_FLG_BIGLPT;
sup->ch.node_type = UBIFS_SB_NODE;
sup->key_hash = UBIFS_KEY_HASH_R5;
sup->flags = cpu_to_le32(sup_flags);
sup->min_io_size = cpu_to_le32(c->min_io_size);
sup->leb_size = cpu_to_le32(c->leb_size);
sup->leb_cnt = cpu_to_le32(c->leb_cnt);
sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
sup->max_bud_bytes = cpu_to_le64(tmp64);
sup->log_lebs = cpu_to_le32(log_lebs);
sup->lpt_lebs = cpu_to_le32(lpt_lebs);
sup->orph_lebs = cpu_to_le32(orph_lebs);
sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
if (c->mount_opts.override_compr)
sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
else
sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
generate_random_uuid(sup->uuid);
main_bytes = (long long)main_lebs * c->leb_size;
tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
if (tmp64 > DEFAULT_MAX_RP_SIZE)
tmp64 = DEFAULT_MAX_RP_SIZE;
sup->rp_size = cpu_to_le64(tmp64);
sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
kfree(sup);
if (err)
return err;
dbg_gen("default superblock created at LEB 0:0");
/* Create default master node */
mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
if (!mst)
return -ENOMEM;
mst->ch.node_type = UBIFS_MST_NODE;
mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
mst->cmt_no = 0;
mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
mst->root_offs = 0;
tmp = ubifs_idx_node_sz(c, 1);
mst->root_len = cpu_to_le32(tmp);
mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
mst->lpt_offs = cpu_to_le32(c->lpt_offs);
mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
mst->nhead_offs = cpu_to_le32(c->nhead_offs);
mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
mst->ltab_offs = cpu_to_le32(c->ltab_offs);
mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
mst->lsave_offs = cpu_to_le32(c->lsave_offs);
mst->lscan_lnum = cpu_to_le32(main_first);
mst->empty_lebs = cpu_to_le32(main_lebs - 2);
mst->idx_lebs = cpu_to_le32(1);
mst->leb_cnt = cpu_to_le32(c->leb_cnt);
/* Calculate lprops statistics */
tmp64 = main_bytes;
tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
mst->total_free = cpu_to_le64(tmp64);
tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
UBIFS_INO_NODE_SZ;
tmp64 += ino_waste;
tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
mst->total_dirty = cpu_to_le64(tmp64);
/* The indexing LEB does not contribute to dark space */
tmp64 = (c->main_lebs - 1) * c->dark_wm;
mst->total_dark = cpu_to_le64(tmp64);
mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
UBI_UNKNOWN);
if (err) {
kfree(mst);
return err;
}
err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0,
UBI_UNKNOWN);
kfree(mst);
if (err)
return err;
dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
/* Create the root indexing node */
tmp = ubifs_idx_node_sz(c, 1);
idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
if (!idx)
return -ENOMEM;
c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
c->key_hash = key_r5_hash;
idx->ch.node_type = UBIFS_IDX_NODE;
idx->child_cnt = cpu_to_le16(1);
ino_key_init(c, &key, UBIFS_ROOT_INO);
br = ubifs_idx_branch(c, idx, 0);
key_write_idx(c, &key, &br->key);
br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0,
UBI_UNKNOWN);
kfree(idx);
if (err)
return err;
dbg_gen("default root indexing node created LEB %d:0",
main_first + DEFAULT_IDX_LEB);
/* Create default root inode */
tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
ino = kzalloc(tmp, GFP_KERNEL);
if (!ino)
return -ENOMEM;
ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
ino->ch.node_type = UBIFS_INO_NODE;
ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
ino->nlink = cpu_to_le32(2);
tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
ino->atime_sec = tmp_le64;
ino->ctime_sec = tmp_le64;
ino->mtime_sec = tmp_le64;
ino->atime_nsec = 0;
ino->ctime_nsec = 0;
ino->mtime_nsec = 0;
ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
/* Set compression enabled by default */
ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
main_first + DEFAULT_DATA_LEB, 0,
UBI_UNKNOWN);
kfree(ino);
if (err)
return err;
dbg_gen("root inode created at LEB %d:0",
main_first + DEFAULT_DATA_LEB);
/*
* The first node in the log has to be the commit start node. This is
* always the case during normal file-system operation. Write a fake
* commit start node to the log.
*/
tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
cs = kzalloc(tmp, GFP_KERNEL);
if (!cs)
return -ENOMEM;
cs->ch.node_type = UBIFS_CS_NODE;
err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
0, UBI_UNKNOWN);
kfree(cs);
ubifs_msg("default file-system created");
return 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;
}