kernel_optimize_test/fs/hpfs/dentry.c
Nick Piggin 621e155a35 fs: change d_compare for rcu-walk
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:19 +11:00

69 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(struct dentry *dentry, 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)
{
dentry->d_op = &hpfs_dentry_operations;
}