Commit 554828ee authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'salted-string-hash' 

This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.

That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.

It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.

Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.

* merge branch 'salted-string-hash':
  fs/dcache.c: Save one 32-bit multiply in dcache lookup
  vfs: make the string hashes salt the hash
parents 194dc870 703b5faf

drivers/staging/lustre/lustre/llite/statahead.c

+5 −3
Original line number Diff line number Diff line
@@ -170,7 +170,8 @@ static inline int is_omitted_entry(struct ll_statahead_info *sai, __u64 index) 
 * Insert it into sai_entries tail when init.

 */

static struct ll_sa_entry *

ll_sa_entry_alloc(struct ll_statahead_info *sai, __u64 index,

ll_sa_entry_alloc(struct dentry *parent,

		  struct ll_statahead_info *sai, __u64 index,

		  const char *name, int len)

{

	struct ll_inode_info *lli;
@@ -217,7 +218,8 @@ ll_sa_entry_alloc(struct ll_statahead_info *sai, __u64 index, 
	dname = (char *)entry + sizeof(struct ll_sa_entry);

	memcpy(dname, name, len);

	dname[len] = 0;

	entry->se_qstr.hash = full_name_hash(name, len);



	entry->se_qstr.hash = full_name_hash(parent, name, len);

	entry->se_qstr.len = len;

	entry->se_qstr.name = dname;
@@ -898,7 +900,7 @@ static void ll_statahead_one(struct dentry *parent, const char *entry_name, 
	int		       rc;

	int		       rc1;



	entry = ll_sa_entry_alloc(sai, sai->sai_index, entry_name,

	entry = ll_sa_entry_alloc(parent, sai, sai->sai_index, entry_name,

				  entry_name_len);

	if (IS_ERR(entry))

		return;

fs/adfs/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -207,7 +207,7 @@ adfs_hash(const struct dentry *parent, struct qstr *qstr) 
	 */

	qstr->len = i = name_len;

	name = qstr->name;

	hash = init_name_hash();

	hash = init_name_hash(parent);

	while (i--) {

		char c;

fs/affs/namei.c

+4 −4
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ affs_get_toupper(struct super_block *sb) 
 * Note: the dentry argument is the parent dentry.

 */

static inline int

__affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate)

__affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t toupper, bool notruncate)

{

	const u8 *name = qstr->name;

	unsigned long hash;
@@ -72,7 +72,7 @@ __affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate) 
	if (retval)

		return retval;



	hash = init_name_hash();

	hash = init_name_hash(dentry);

	len = min(qstr->len, AFFSNAMEMAX);

	for (; len > 0; name++, len--)

		hash = partial_name_hash(toupper(*name), hash);
@@ -84,7 +84,7 @@ __affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate) 
static int

affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)

{

	return __affs_hash_dentry(qstr, affs_toupper,

	return __affs_hash_dentry(dentry, qstr, affs_toupper,

				  affs_nofilenametruncate(dentry));



}
@@ -92,7 +92,7 @@ affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr) 
static int

affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)

{

	return __affs_hash_dentry(qstr, affs_intl_toupper,

	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,

				  affs_nofilenametruncate(dentry));



}

fs/autofs4/waitq.c

+1 −1
Original line number Diff line number Diff line
@@ -398,7 +398,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, 
		}

	}

	qstr.name = name;

	qstr.hash = full_name_hash(name, qstr.len);

	qstr.hash = full_name_hash(dentry, name, qstr.len);



	if (mutex_lock_interruptible(&sbi->wq_mutex)) {

		kfree(qstr.name);

fs/ceph/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -1164,7 +1164,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, 


			dname.name = rinfo->dname;

			dname.len = rinfo->dname_len;

			dname.hash = full_name_hash(dname.name, dname.len);

			dname.hash = full_name_hash(parent, dname.name, dname.len);

			vino.ino = le64_to_cpu(rinfo->targeti.in->ino);

			vino.snap = le64_to_cpu(rinfo->targeti.in->snapid);

retry_lookup:
@@ -1508,7 +1508,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, 


		dname.name = rde->name;

		dname.len = rde->name_len;

		dname.hash = full_name_hash(dname.name, dname.len);

		dname.hash = full_name_hash(parent, dname.name, dname.len);



		vino.ino = le64_to_cpu(rde->inode.in->ino);

		vino.snap = le64_to_cpu(rde->inode.in->snapid);

CRA Git | Maintained and supported by SUSTech CRA and CCSE