patch-2.4.15 linux/fs/intermezzo/dcache.c

• Lines: 140
• Date: Tue Nov 13 09:20:56 2001
• Orig file: v2.4.14/linux/fs/intermezzo/dcache.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.14/linux/fs/intermezzo/dcache.c linux/fs/intermezzo/dcache.c
@@ -0,0 +1,139 @@
+/*
+ * Directory operations for InterMezzo filesystem
+ * Original version: (C) 1996 P. Braam and M. Callahan
+ * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
+ *
+ * Stelias encourages users to contribute improvements to
+ * the InterMezzo project. Contact Peter Braam (coda@stelias.com).
+ */
+
+#define __NO_VERSION__
+#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 <linux/slab.h>
+#include <asm/segment.h>
+#include <asm/uaccess.h>
+#include <linux/string.h>
+
+#include <linux/intermezzo_fs.h>
+
+static int presto_dentry_revalidate(struct dentry *de, int );
+static kmem_cache_t * presto_dentry_slab;
+
+/* called when a cache lookup succeeds */
+static int presto_dentry_revalidate(struct dentry *de, int flag)
+{
+	struct inode *inode = de->d_inode;
+	ENTRY;
+	if (!inode) {
+		EXIT;
+		return 1;
+	}
+	if (is_bad_inode(inode)) {
+		EXIT;
+		return 0;
+	}
+
+	if ( S_ISDIR(inode->i_mode) ) {
+		EXIT;
+		return (presto_chk(de, PRESTO_DATA) &&
+			(presto_chk(de, PRESTO_ATTR)));
+	} else {
+		EXIT;
+		return presto_chk(de, PRESTO_ATTR);
+	}
+}
+
+static void presto_d_release(struct dentry *dentry)
+{
+        if (!presto_d2d(dentry)) {
+                /* This should really only happen in the case of a dentry
+                 * with no inode. */
+                return;
+        }
+
+        presto_d2d(dentry)->dd_count--;
+
+        if (! presto_d2d(dentry)->dd_count) {
+                kmem_cache_free(presto_dentry_slab, presto_d2d(dentry));
+		dentry->d_fsdata = NULL;
+        }
+}
+
+struct dentry_operations presto_dentry_ops = 
+{
+	d_revalidate: presto_dentry_revalidate,
+        d_release: presto_d_release
+};
+
+
+// XXX THIS DEPENDS ON THE KERNEL LOCK!
+
+void presto_set_dd(struct dentry * dentry)
+{
+        ENTRY;
+        if (dentry == NULL)
+                BUG();
+
+        if (dentry->d_fsdata) {
+                printk("VERY BAD: dentry: %p\n", dentry);
+                if (dentry->d_inode)
+                        printk("    inode: %ld\n", dentry->d_inode->i_ino);
+                EXIT;
+                return;
+        }
+
+        if (dentry->d_inode == NULL) {
+                dentry->d_fsdata = kmem_cache_alloc(presto_dentry_slab,
+                                                    SLAB_KERNEL);
+                memset(dentry->d_fsdata, 0, sizeof(struct presto_dentry_data));
+                presto_d2d(dentry)->dd_count = 1;
+                EXIT;
+                return;
+        }
+
+        /* If there's already a dentry for this inode, share the data */
+        if (dentry->d_alias.next != &dentry->d_inode->i_dentry ||
+            dentry->d_alias.prev != &dentry->d_inode->i_dentry) {
+                struct dentry *de;
+
+                if (dentry->d_alias.next != &dentry->d_inode->i_dentry)
+                        de = list_entry(dentry->d_alias.next, struct dentry,
+                                        d_alias);
+                else
+                        de = list_entry(dentry->d_alias.prev, struct dentry,
+                                        d_alias);
+
+                dentry->d_fsdata = de->d_fsdata;
+                presto_d2d(dentry)->dd_count++;
+                EXIT;
+                return;
+        }
+
+        dentry->d_fsdata = kmem_cache_alloc(presto_dentry_slab, SLAB_KERNEL);
+        memset(dentry->d_fsdata, 0, sizeof(struct presto_dentry_data));
+        presto_d2d(dentry)->dd_count = 1;
+        EXIT;
+        return; 
+}
+
+void presto_init_ddata_cache(void)
+{
+        ENTRY;
+        presto_dentry_slab =
+                kmem_cache_create("presto_cache",
+                                  sizeof(struct presto_dentry_data), 0,
+                                  SLAB_HWCACHE_ALIGN, NULL,
+                                  NULL);
+        EXIT;
+}
+
+void presto_cleanup_ddata_cache(void)
+{
+        kmem_cache_destroy(presto_dentry_slab);
+}