kernel-ark/fs/hpfs/dentry.c
Nick Piggin fb045adb99 fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00

70 lines
1.6 KiB
C

/*
* linux/fs/hpfs/dentry.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* dcache operations
*/
#include "hpfs_fn.h"
/*
* Note: the dentry argument is the parent dentry.
*/
static int hpfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
struct qstr *qstr)
{
unsigned long hash;
int i;
unsigned l = qstr->len;
if (l == 1) if (qstr->name[0]=='.') goto x;
if (l == 2) if (qstr->name[0]=='.' || qstr->name[1]=='.') goto x;
hpfs_adjust_length(qstr->name, &l);
/*if (hpfs_chk_name(qstr->name,&l))*/
/*return -ENAMETOOLONG;*/
/*return -ENOENT;*/
x:
hash = init_name_hash();
for (i = 0; i < l; i++)
hash = partial_name_hash(hpfs_upcase(hpfs_sb(dentry->d_sb)->sb_cp_table,qstr->name[i]), hash);
qstr->hash = end_name_hash(hash);
return 0;
}
static int hpfs_compare_dentry(const struct dentry *parent,
const struct inode *pinode,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name)
{
unsigned al = len;
unsigned bl = name->len;
hpfs_adjust_length(str, &al);
/*hpfs_adjust_length(b->name, &bl);*/
/*
* 'str' is the nane of an already existing dentry, so the name
* must be valid. 'name' must be validated first.
*/
if (hpfs_chk_name(name->name, &bl))
return 1;
if (hpfs_compare_names(parent->d_sb, str, al, name->name, bl, 0))
return 1;
return 0;
}
static const struct dentry_operations hpfs_dentry_operations = {
.d_hash = hpfs_hash_dentry,
.d_compare = hpfs_compare_dentry,
};
void hpfs_set_dentry_operations(struct dentry *dentry)
{
d_set_d_op(dentry, &hpfs_dentry_operations);
}