Commit d63d61c1 authored by Richard Weinberger's avatar Richard Weinberger

ubifs: Implement UBIFS_FLG_DOUBLE_HASH

This feature flag indicates that all directory entry nodes have a 32bit
cookie set and therefore UBIFS is allowed to perform lookups by hash.
Signed-off-by: 's avatarRichard Weinberger <richard@nod.at>
parent cc41a536
......@@ -501,6 +501,14 @@ static void mark_inode_clean(struct ubifs_info *c, struct ubifs_inode *ui)
ui->dirty = 0;
}
static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent)
{
if (c->double_hash)
dent->cookie = prandom_u32();
else
dent->cookie = 0;
}
/**
* ubifs_jnl_update - update inode.
* @c: UBIFS file-system description object
......@@ -589,7 +597,7 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
dent->nlen = cpu_to_le16(fname_len(nm));
memcpy(dent->name, fname_name(nm), fname_len(nm));
dent->name[fname_len(nm)] = '\0';
dent->cookie = prandom_u32();
set_dent_cookie(c, dent);
zero_dent_node_unused(dent);
ubifs_prep_grp_node(c, dent, dlen, 0);
......@@ -1125,7 +1133,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
dent->nlen = cpu_to_le16(fname_len(new_nm));
memcpy(dent->name, fname_name(new_nm), fname_len(new_nm));
dent->name[fname_len(new_nm)] = '\0';
dent->cookie = prandom_u32();
set_dent_cookie(c, dent);
zero_dent_node_unused(dent);
ubifs_prep_grp_node(c, dent, dlen1, 0);
......@@ -1144,7 +1152,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
dent2->nlen = cpu_to_le16(fname_len(old_nm));
memcpy(dent2->name, fname_name(old_nm), fname_len(old_nm));
dent2->name[fname_len(old_nm)] = '\0';
dent2->cookie = prandom_u32();
set_dent_cookie(c, dent2);
zero_dent_node_unused(dent2);
ubifs_prep_grp_node(c, dent2, dlen2, 0);
......
......@@ -163,6 +163,7 @@ static int create_default_filesystem(struct ubifs_info *c)
tmp64 = (long long)max_buds * c->leb_size;
if (big_lpt)
sup_flags |= UBIFS_FLG_BIGLPT;
sup_flags |= UBIFS_FLG_DOUBLE_HASH;
sup->ch.node_type = UBIFS_SB_NODE;
sup->key_hash = UBIFS_KEY_HASH_R5;
......@@ -620,6 +621,7 @@ int ubifs_read_superblock(struct ubifs_info *c)
memcpy(&c->uuid, &sup->uuid, 16);
c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH);
/* Automatically increase file system size to the maximum size */
c->old_leb_cnt = c->leb_cnt;
......
......@@ -1930,6 +1930,9 @@ int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,
int err;
const struct ubifs_dent_node *dent = node;
if (!c->double_hash)
return -EOPNOTSUPP;
/*
* We assume that in most of the cases there are no name collisions and
* 'ubifs_tnc_lookup()' returns us the right direntry.
......
......@@ -418,10 +418,13 @@ enum {
*
* UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
* UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
* UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to
* support 64bit cookies for lookups by hash
*/
enum {
UBIFS_FLG_BIGLPT = 0x02,
UBIFS_FLG_SPACE_FIXUP = 0x04,
UBIFS_FLG_DOUBLE_HASH = 0x08,
};
/**
......
......@@ -1006,6 +1006,7 @@ struct ubifs_debug_info;
*
* @big_lpt: flag that LPT is too big to write whole during commit
* @space_fixup: flag indicating that free space in LEBs needs to be cleaned up
* @double_hash: flag indicating that we can do lookups by hash
* @no_chk_data_crc: do not check CRCs when reading data nodes (except during
* recovery)
* @bulk_read: enable bulk-reads
......@@ -1248,6 +1249,7 @@ struct ubifs_info {
unsigned int big_lpt:1;
unsigned int space_fixup:1;
unsigned int double_hash:1;
unsigned int no_chk_data_crc:1;
unsigned int bulk_read:1;
unsigned int default_compr:2;
......
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