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* Cache operations for Coda.
* For Linux 2.1: (C) 1997 Carnegie Mellon University
*
* Carnegie Mellon encourages users of this code to contribute improvements
* to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/locks.h>
#include <asm/segment.h>
#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/coda.h>
#include <linux/coda_linux.h>
#include <linux/coda_psdev.h>
#include <linux/coda_fs_i.h>
#include <linux/coda_cache.h>
static void coda_ccinsert(struct coda_cache *el, struct super_block *sb);
static void coda_cninsert(struct coda_cache *el, struct coda_inode_info *cii);
static void coda_ccremove(struct coda_cache *el);
static void coda_cnremove(struct coda_cache *el);
static void coda_cache_create(struct inode *inode, int mask);
static struct coda_cache * coda_cache_find(struct inode *inode);
/* insert a acl-cache entry in sb list */
static void coda_ccinsert(struct coda_cache *el, struct super_block *sb)
{
struct coda_sb_info *sbi = coda_sbp(sb);
ENTRY;
if ( !sbi || !el) {
printk("coda_ccinsert: NULL sbi or el!\n");
return ;
}
list_add(&el->cc_cclist, &sbi->sbi_cchead);
}
/* insert a acl-cache entry in the inode list */
static void coda_cninsert(struct coda_cache *el, struct coda_inode_info *cii)
{
ENTRY;
if ( !cii || !el) {
printk("coda_cninsert: NULL cii or el!\n");
return ;
}
list_add(&el->cc_cnlist, &cii->c_cnhead);
}
/* remove a cache entry from the superblock list */
static void coda_ccremove(struct coda_cache *el)
{
ENTRY;
if (el->cc_cclist.next && el->cc_cclist.prev)
list_del(&el->cc_cclist);
else
printk("coda_cnremove: trying to remove 0 entry!");
}
/* remove a cache entry from the inode's list */
static void coda_cnremove(struct coda_cache *el)
{
ENTRY;
if (el->cc_cnlist.next && el->cc_cnlist.prev)
list_del(&el->cc_cnlist);
else
printk("coda_cnremove: trying to remove 0 entry!");
}
/* create a new cache entry and enlist it */
static void coda_cache_create(struct inode *inode, int mask)
{
struct coda_inode_info *cii = ITOC(inode);
struct super_block *sb = inode->i_sb;
struct coda_cache *cc = NULL;
ENTRY;
CODA_ALLOC(cc, struct coda_cache *, sizeof(*cc));
if ( !cc ) {
printk("Out of memory in coda_cache_enter!\n");
return;
}
coda_load_creds(&cc->cc_cred);
cc->cc_mask = mask;
coda_cninsert(cc, cii);
coda_ccinsert(cc, sb);
}
/* see if there is a match for the current
credentials already */
static struct coda_cache * coda_cache_find(struct inode *inode)
{
struct coda_inode_info *cii = ITOC(inode);
struct list_head *lh, *le;
struct coda_cache *cc = NULL;
le = lh = &cii->c_cnhead;
while( (le = le->next ) != lh ) {
/* compare name and creds */
cc = list_entry(le, struct coda_cache, cc_cnlist);
if ( !coda_cred_ok(&cc->cc_cred) )
continue;
CDEBUG(D_CACHE, "HIT for ino %ld\n", inode->i_ino );
return cc; /* cache hit */
}
return NULL;
}
/* create or extend an acl cache hit */
void coda_cache_enter(struct inode *inode, int mask)
{
struct coda_cache *cc;
cc = coda_cache_find(inode);
if ( cc ) {
cc->cc_mask |= mask;
} else {
coda_cache_create(inode, mask);
}
}
/* remove all cached acl matches from an inode */
void coda_cache_clear_inode(struct inode *inode)
{
struct list_head *lh, *le;
struct coda_inode_info *cii;
struct coda_cache *cc;
ENTRY;
if ( !inode ) {
CDEBUG(D_CACHE, "coda_cache_clear_inode: NULL inode\n");
return;
}
cii = ITOC(inode);
lh = le = &cii->c_cnhead;
while ( (le = le->next ) != lh ) {
cc = list_entry(le, struct coda_cache, cc_cnlist);
coda_cnremove(cc);
coda_ccremove(cc);
CODA_FREE(cc, sizeof(*cc));
}
}
/* remove all acl caches */
void coda_cache_clear_all(struct super_block *sb)
{
struct list_head *lh, *le;
struct coda_cache *cc;
struct coda_sb_info *sbi = coda_sbp(sb);
if ( !sbi ) {
printk("coda_cache_clear_all: NULL sbi\n");
return;
}
if ( list_empty(&sbi->sbi_cchead) )
return;
lh = le = &sbi->sbi_cchead;
while ( (le = le->next ) != lh ) {
cc = list_entry(le, struct coda_cache, cc_cclist);
coda_cnremove(cc);
coda_ccremove(cc);
CODA_FREE(cc, sizeof(*cc));
}
}
/* remove all acl caches for a principal */
void coda_cache_clear_cred(struct super_block *sb, struct coda_cred *cred)
{
struct list_head *lh, *le;
struct coda_cache *cc;
struct coda_sb_info *sbi = coda_sbp(sb);
if ( !sbi ) {
printk("coda_cache_clear_all: NULL sbi\n");
return;
}
if (list_empty(&sbi->sbi_cchead))
return;
lh = le = &sbi->sbi_cchead;
while ( (le = le->next ) != lh ) {
cc = list_entry(le, struct coda_cache, cc_cclist);
if ( coda_cred_eq(&cc->cc_cred, cred)) {
coda_cnremove(cc);
coda_ccremove(cc);
CODA_FREE(cc, sizeof(*cc));
}
}
}
/* check if the mask has been matched against the acl
already */
int coda_cache_check(struct inode *inode, int mask)
{
struct coda_inode_info *cii = ITOC(inode);
struct list_head *lh, *le;
struct coda_cache *cc = NULL;
le = lh = &cii->c_cnhead;
while( (le = le->next ) != lh ) {
/* compare name and creds */
cc = list_entry(le, struct coda_cache, cc_cnlist);
if ( (cc->cc_mask & mask) != mask )
continue;
if ( !coda_cred_ok(&cc->cc_cred) )
continue;
CDEBUG(D_CACHE, "HIT for ino %ld\n", inode->i_ino );
return 1; /* cache hit */
}
CDEBUG(D_CACHE, "MISS for ino %ld\n", inode->i_ino );
return 0;
}
/* DCACHE & ZAPPING related stuff */
/* the following routines set flags in the inodes. They are
detected by:
- a dentry method: coda_dentry_revalidate (for lookups)
if the flag is C_PURGE
- an inode method coda_revalidate (for attributes) if the
flag is C_ATTR
*/
static void coda_flag_children(struct dentry *parent, int flag)
{
struct list_head *child;
struct dentry *de;
child = parent->d_subdirs.next;
while ( child != &parent->d_subdirs ) {
de = list_entry(child, struct dentry, d_child);
coda_flag_inode(de->d_inode, flag);
CDEBUG(D_CACHE, "%d for %*s/%*s\n", flag,
de->d_name.len, de->d_name.name,
de->d_parent->d_name.len, de->d_parent->d_name.name);
child = child->next;
if ( !de->d_inode )
d_drop(de);
}
return;
}
void coda_flag_alias_children(struct inode *inode, int flag)
{
struct list_head *alias;
struct dentry *alias_de;
if ( !inode )
return;
alias = inode->i_dentry.next;
while ( alias != &inode->i_dentry ) {
alias_de = list_entry(alias, struct dentry, d_alias);
if ( !alias_de ) {
printk("Null alias list for inode %ld\n", inode->i_ino);
return;
}
coda_flag_children(alias_de, flag);
alias= alias->next;
}
}
void coda_flag_inode(struct inode *inode, int flag)
{
struct coda_inode_info *cii;
if ( !inode ) {
CDEBUG(D_CACHE, " no inode!\n");
return;
}
cii = ITOC(inode);
cii->c_flags |= flag;
}
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