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: Richard Weinberger <rich...@nod.at>
---
fs/ubifs/journal.c | 14 +++++++++++---
fs/ubifs/sb.c | 2 ++
fs/ubifs/tnc.c | 3 +++
fs/ubifs/ubifs-media.h | 3 +++
fs/ubifs/ubifs.h | 2 ++
5 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index dcecfbfbf40e..c8a483a0df2c 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -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);
@@ -993,7 +1001,7 @@ 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);
@@ -1006,7 +1014,7 @@ 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);
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index 3cbb904a6d7d..4a2b4c361587 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -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;
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 1eaf994addb4..02205a68f851 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -1939,6 +1939,9 @@ 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.
diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h
index 249124d9a801..0cbdc6b70a00 100644
--- a/fs/ubifs/ubifs-media.h
+++ b/fs/ubifs/ubifs-media.h
@@ -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,
};
/**
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 294e4047bcc0..59d55887b3d8 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1014,6 +1014,7 @@ 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
@@ -1256,6 +1257,7 @@ 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;
--
2.7.3
