patch-2.1.76 linux/fs/coda/cache.c

• Lines: 330
• Date: Mon Dec 22 08:40:49 1997
• Orig file: v2.1.75/linux/fs/coda/cache.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.75/linux/fs/coda/cache.c linux/fs/coda/cache.c
@@ -0,0 +1,329 @@
+/*
+ * 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_cnode.h>
+#include <linux/coda_cache.h>
+
+/* Keep various stats */
+struct cfsnc_statistics cfsnc_stat;
+
+
+/* we need to call INIT_LIST_HEAD on cnp->c_cnhead and sbi->sbi_cchead */
+
+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);
+}
+
+void coda_cninsert(struct coda_cache *el, struct cnode *cnp)
+{
+ENTRY;
+	if ( !cnp ||  !el) {
+		printk("coda_cninsert: NULL cnp or el!\n");
+		return ;
+	}
+	list_add(&el->cc_cnlist, &cnp->c_cnhead);
+}
+
+void coda_ccremove(struct coda_cache *el)
+{
+ENTRY;
+	list_del(&el->cc_cclist);
+}
+
+void coda_cnremove(struct coda_cache *el)
+{
+ENTRY;
+	list_del(&el->cc_cnlist);
+}
+
+
+void coda_cache_create(struct inode *inode, int mask)
+{
+	struct cnode *cnp = 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, cnp);
+	coda_ccinsert(cc, sb);
+}
+
+struct coda_cache * coda_cache_find(struct inode *inode)
+{
+	struct cnode *cnp = ITOC(inode);
+	struct list_head *lh, *le;
+	struct coda_cache *cc = NULL;
+	
+	le = lh = &cnp->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;
+}
+
+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);
+	}
+}
+
+void coda_cache_clear_cnp(struct cnode *cnp)
+{
+	struct list_head *lh, *le;
+	struct coda_cache *cc;
+
+	if ( !cnp ) {
+		printk("coda_cache_cnp_clear: NULL cnode\n");
+		return;
+	}
+	
+	lh = le = &cnp->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));
+	}
+}
+
+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;
+	}
+	
+	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));
+	}
+}
+
+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;
+	}
+	
+	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));
+		}
+	}
+}
+		
+
+int coda_cache_check(struct inode *inode, int mask)
+{
+	struct cnode *cnp = ITOC(inode);
+	struct list_head *lh, *le;
+	struct coda_cache *cc = NULL;
+	
+	le = lh = &cnp->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;
+}
+
+
+/*   DENTRY related stuff */
+
+/* when the dentry count falls to 0 this is called. If Venus has
+   asked for it to be flushed, we take it out of the dentry hash 
+   table with d_drop */
+
+static void coda_flag_children(struct dentry *parent)
+{
+	struct list_head *child;
+	struct cnode *cnp;
+	struct dentry *de;
+	char str[50];
+
+	child = parent->d_subdirs.next;
+	while ( child != &parent->d_subdirs ) {
+		de = list_entry(child, struct dentry, d_child);
+		cnp = ITOC(de->d_inode);
+		if (cnp) 
+			cnp->c_flags |= C_ZAPFID;
+		CDEBUG(D_CACHE, "ZAPFID for %s\n", coda_f2s(&cnp->c_fid, str));
+		
+		child = child->next;
+	}
+	return; 
+}
+
+/* flag dentry and possibly  children of a dentry with C_ZAPFID */
+void  coda_dentry_delete(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct cnode *cnp = NULL;
+	ENTRY;
+
+	if (inode) { 
+		cnp = ITOC(inode);
+		if ( cnp ) 
+			CHECK_CNODE(cnp);
+	} else {
+		printk("No inode for dentry_delete!\n");
+		return;
+	}
+
+	
+	if ( !cnp ) {
+		printk("No cnode for dentry_delete!\n");
+		return;
+	}
+
+	if ( cnp->c_flags & (C_ZAPFID | C_ZAPDIR) )
+		d_drop(dentry);
+	if ( (cnp->c_flags & C_ZAPDIR) && S_ISDIR(inode->i_mode) ) {
+		coda_flag_children(dentry);
+	}
+	return;
+}
+
+/* the dache will notice the flags and drop entries (possibly with
+   children) the moment they are no longer in use  */
+void coda_zapfid(struct ViceFid *fid, struct super_block *sb, int flag)
+{
+	struct inode *inode = NULL;
+	struct cnode *cnp;
+
+	ENTRY;
+ 
+	if ( !sb ) {
+		printk("coda_zapfid: no sb!\n");
+		return;
+	}
+
+	if ( !fid ) {
+		printk("coda_zapfid: no fid!\n");
+		return;
+	}
+
+	inode = coda_fid_to_inode(fid, sb);
+	if ( !inode ) {
+		printk("coda_zapfid: no inode!\n");
+		return;
+	}
+	cnp = ITOC(inode);
+	CHECK_CNODE(cnp);
+	if ( !cnp ) {
+		printk("coda_zapfid: no cnode!\n");
+		return;
+	}
+	cnp->c_flags |= flag;
+	coda_cache_clear_cnp(cnp);
+}
+		
+
+int
+cfsnc_nc_info(char *buffer, char **start, off_t offset, int length, int dummy)
+{
+        int len=0;
+        off_t begin;
+	
+	/* 	cfsnc_gather_stats(); */
+
+	/* this works as long as we are below 1024 characters! */    
+	len += sprintf(buffer,"Coda minicache statistics\n\n");
+	len += sprintf(buffer+len, "cfsnc_hits : %d\n", cfsnc_stat.hits);
+	len += sprintf(buffer+len, "cfsnc_misses : %d\n", cfsnc_stat.misses);
+	len += sprintf(buffer+len, "cfsnc_enters : %d\n", cfsnc_stat.enters);
+	len += sprintf(buffer+len, "cfsnc_dbl_enters : %d\n", cfsnc_stat.dbl_enters);
+	len += sprintf(buffer+len, "cfsnc_long_name_enters : %d\n", cfsnc_stat.long_name_enters);
+	len += sprintf(buffer+len, "cfsnc_long_name_lookups : %d\n", cfsnc_stat.long_name_lookups);
+	len += sprintf(buffer+len, "cfsnc_long_remove : %d\n", cfsnc_stat.long_remove);
+	len += sprintf(buffer+len, "cfsnc_lru_rm : %d\n", cfsnc_stat.lru_rm);
+	len += sprintf(buffer+len, "cfsnc_zapPfids : %d\n", cfsnc_stat.zapPfids);
+	len += sprintf(buffer+len, "cfsnc_zapFids : %d\n", cfsnc_stat.zapFids);
+	len += sprintf(buffer+len, "cfsnc_zapFile : %d\n", cfsnc_stat.zapFile);
+	len += sprintf(buffer+len, "cfsnc_zapUsers : %d\n", cfsnc_stat.zapUsers);
+	len += sprintf(buffer+len, "cfsnc_Flushes : %d\n", cfsnc_stat.Flushes);
+	len += sprintf(buffer+len, "cfsnc_SumLen : %d\n", cfsnc_stat.Sum_bucket_len);
+	len += sprintf(buffer+len, "cfsnc_Sum2Len : %d\n", cfsnc_stat.Sum2_bucket_len);
+	len += sprintf(buffer+len,  "cfsnc_# 0 len : %d\n", cfsnc_stat.Num_zero_len);
+	len += sprintf(buffer+len,  "cfsnc_MaxLen : %d\n", cfsnc_stat.Max_bucket_len);
+	len += sprintf(buffer+len,  "cfsnc_SearchLen : %d\n", cfsnc_stat.Search_len);
+       	begin =  offset;
+       	*start = buffer + begin;
+       	len -= begin;
+	
+        if(len>length)
+                len = length;
+	if (len< 0)
+		len = 0;
+        return len;
+}