209-mini_fo.patch

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+#else
+mini_fo_d_revalidate(dentry_t *dentry, int flags)
+#endif
+{
+	int err1 = 1; /* valid = 1, invalid = 0 */
+	int err2 = 1;
+	dentry_t *hidden_dentry;
+	dentry_t *hidden_sto_dentry;
+
+
+	check_mini_fo_dentry(dentry);
+
+	hidden_dentry  = dtohd(dentry);
+	hidden_sto_dentry = dtohd2(dentry);
+
+	if(hidden_dentry &&
+	   hidden_dentry->d_op &&
+	   hidden_dentry->d_op->d_revalidate) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+		err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, nd);
+#else
+		err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, flags);
+#endif
+	}
+	if(hidden_sto_dentry &&
+	   hidden_sto_dentry->d_op &&
+	   hidden_sto_dentry->d_op->d_revalidate) {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+		err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry, 
+							     nd);
+#else
+		err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry, 
+							     flags);
+#endif
+	}
+
+	/* mk: if one of the lower level dentries are valid,
+	 * the mini_fo dentry is too.
+	 */
+	return (err1 || err2);
+}
+
+
+STATIC int
+mini_fo_d_hash(dentry_t *dentry, qstr_t *name)
+{
+	int err = 0;
+	dentry_t *hidden_dentry;
+	dentry_t *hidden_sto_dentry;
+
+	/* hidden_dentry = mini_fo_hidden_dentry(dentry);
+	 * hidden_sto_dentry = mini_fo_hidden_sto_dentry(dentry); */
+
+	/* state 1, 3, 4, 5: build the hash for the storage dentry */
+	if((dtopd(dentry)->state == MODIFIED) ||
+	   (dtopd(dentry)->state == CREATED) ||
+	   (dtopd(dentry)->state == DEL_REWRITTEN) ||
+	   (dtopd(dentry)->state == DELETED)) {
+		hidden_sto_dentry = dtohd2(dentry);
+		if(hidden_sto_dentry &&
+		   hidden_sto_dentry->d_op &&
+		   hidden_sto_dentry->d_op->d_hash) {
+			err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
+		}
+		goto out;
+	}
+	/* state 2: build the hash for the base dentry */
+	if(dtopd(dentry)->state == UNMODIFIED) {
+		hidden_dentry = dtohd(dentry);
+		if(hidden_dentry &&
+		   hidden_dentry->d_op &&
+		   hidden_dentry->d_op->d_hash) {
+			err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
+		}
+		goto out;
+	}
+	/* state 6: build hash for the dentry that exists */
+	if(dtopd(dentry)->state == NON_EXISTANT) {
+		hidden_sto_dentry = dtohd2(dentry);
+		if(hidden_sto_dentry &&
+		   hidden_sto_dentry->d_op &&
+		   hidden_sto_dentry->d_op->d_hash) {
+			err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
+			goto out;
+		}
+		hidden_dentry = dtohd(dentry);
+		if(hidden_dentry &&
+		   hidden_dentry->d_op &&
+		   hidden_dentry->d_op->d_hash) {
+			err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
+			goto out;
+		}
+	}
+
+	printk(KERN_CRIT "mini_fo: d_hash: invalid state detected.\n");
+
+ out:
+	return err;
+}
+
+
+STATIC int
+mini_fo_d_compare(dentry_t *dentry, qstr_t *a, qstr_t *b)
+{
+	int err;
+	dentry_t *hidden_dentry=NULL;
+
+	/* hidden_dentry = mini_fo_hidden_dentry(dentry); */
+	if(dtohd2(dentry))
+		hidden_dentry = dtohd2(dentry);
+	else if(dtohd(dentry))
+		hidden_dentry = dtohd(dentry);
+
+	if (hidden_dentry && hidden_dentry->d_op && hidden_dentry->d_op->d_compare) {
+		err = hidden_dentry->d_op->d_compare(hidden_dentry, a, b);
+	} else {
+		err = ((a->len != b->len) || memcmp(a->name, b->name, b->len));
+	}
+
+	return err;
+}
+
+
+int
+mini_fo_d_delete(dentry_t *dentry)
+{
+	dentry_t *hidden_dentry;
+	dentry_t *hidden_sto_dentry;
+	int err = 0;
+
+	/* this could be a negative dentry, so check first */
+	if (!dtopd(dentry)) {
+		printk(KERN_CRIT "mini_fo_d_delete: negative dentry passed.\n");
+		goto out;
+	}
+	hidden_dentry = dtohd(dentry);
+	hidden_sto_dentry = dtohd2(dentry);
+
+	if(hidden_dentry) {
+		if(hidden_dentry->d_op &&
+		   hidden_dentry->d_op->d_delete) {
+			err = hidden_dentry->d_op->d_delete(hidden_dentry);
+		}
+	}
+	if(hidden_sto_dentry) {
+		if(hidden_sto_dentry->d_op &&
+		   hidden_sto_dentry->d_op->d_delete) {
+			err = hidden_sto_dentry->d_op->d_delete(hidden_sto_dentry);
+		}
+	}
+
+ out:
+	return err;
+}
+
+
+void
+mini_fo_d_release(dentry_t *dentry)
+{
+	dentry_t *hidden_dentry;
+	dentry_t *hidden_sto_dentry;
+
+
+	/* this could be a negative dentry, so check first */
+	if (!dtopd(dentry)) {
+		printk(KERN_CRIT "mini_fo_d_release: no private data.\n");
+		goto out;
+	}
+	hidden_dentry = dtohd(dentry);
+	hidden_sto_dentry = dtohd2(dentry);
+
+	if(hidden_dentry) {
+		/* decrement hidden dentry's counter and free its inode */
+		dput(hidden_dentry);
+	}
+	if(hidden_sto_dentry) {
+                /* decrement hidden dentry's counter and free its inode */
+		dput(hidden_sto_dentry);
+	}
+
+	/* free private data (mini_fo_dentry_info) here */
+	kfree(dtopd(dentry));
+	__dtopd(dentry) = NULL;	/* just to be safe */
+ out:
+	return;
+}
+
+
+/*
+ * we don't really need mini_fo_d_iput, because dentry_iput will call iput() if
+ * mini_fo_d_iput is not defined. We left this implemented for ease of
+ * tracing/debugging.
+ */
+void
+mini_fo_d_iput(dentry_t *dentry, inode_t *inode)
+{
+	iput(inode);
+}
+
+
+struct dentry_operations mini_fo_dops = {
+	d_revalidate:	mini_fo_d_revalidate,
+	d_hash:		mini_fo_d_hash,
+	d_compare:		mini_fo_d_compare,
+	d_release:		mini_fo_d_release,
+	d_delete:		mini_fo_d_delete,
+	d_iput:		mini_fo_d_iput,
+};
Index: linux-2.6.21.7/fs/mini_fo/file.c
===================================================================
--- /dev/null
+++ linux-2.6.21.7/fs/mini_fo/file.c
@@ -0,0 +1,713 @@
+/*
+ * Copyright (c) 1997-2003 Erez Zadok
+ * Copyright (c) 2001-2003 Stony Brook University
+ *
+ * For specific licensing information, see the COPYING file distributed with
+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
+ *
+ * This Copyright notice must be kept intact and distributed with all
+ * fistgen sources INCLUDING sources generated by fistgen.
+ */
+/*
+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+/*
+ *  $Id$
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "fist.h"
+#include "mini_fo.h"
+#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
+
+/*******************
+ * File Operations *
+ *******************/
+
+STATIC loff_t
+mini_fo_llseek(file_t *file, loff_t offset, int origin)
+{
+	loff_t err;
+	file_t *hidden_file = NULL;
+
+	if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
+		/* Check if trying to llseek from a directory */
+		err = -EISDIR;
+		goto out;
+	}
+	if (ftopd(file) != NULL) {
+		if(ftohf2(file)) {
+			hidden_file = ftohf2(file);
+		} else {
+			hidden_file = ftohf(file);
+		}
+	}
+
+	/* always set hidden position to this one */
+	hidden_file->f_pos = file->f_pos;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
+	memcpy(&(hidden_file->f_ra), 
+	       &(file->f_ra), 
+	       sizeof(struct file_ra_state));
+#else
+	if (file->f_reada) { /* update readahead information if needed */
+		hidden_file->f_reada = file->f_reada;
+		hidden_file->f_ramax = file->f_ramax;
+		hidden_file->f_raend = file->f_raend;
+		hidden_file->f_ralen = file->f_ralen;
+		hidden_file->f_rawin = file->f_rawin;
+	}
+#endif
+	if (hidden_file->f_op && hidden_file->f_op->llseek)
+		err = hidden_file->f_op->llseek(hidden_file, offset, origin);
+	else
+		err = generic_file_llseek(hidden_file, offset, origin);
+
+	if (err < 0)
+		goto out;
+
+	if (err != file->f_pos) {
+		file->f_pos = err;
+		// ION maybe this?
+		// 	file->f_pos = hidden_file->f_pos;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+		file->f_reada = 0;
+#endif
+		file->f_version++;
+	}
+
+ out:
+	return err;
+}
+
+
+/* mk: fanout capable */
+STATIC ssize_t
+mini_fo_read(file_t *file, char *buf, size_t count, loff_t *ppos)
+{
+	int err = -EINVAL;
+	file_t *hidden_file = NULL;
+	loff_t pos = *ppos;
+
+	if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
+		/* Check if trying to read from a directory */
+		/* printk(KERN_CRIT "mini_fo_read: ERROR: trying to read data from a directory.\n"); */
+		err = -EISDIR;
+		goto out;
+	}
+
+	if (ftopd(file) != NULL) {
+		if(ftohf2(file)) {
+			hidden_file = ftohf2(file);
+		} else {
+			hidden_file = ftohf(file);
+		}
+	}
+
+	if (!hidden_file->f_op || !hidden_file->f_op->read)
+		goto out;
+
+	err = hidden_file->f_op->read(hidden_file, buf, count, &pos);
+	*ppos = pos;
+
+	if (err >= 0) {
+		/* atime should also be updated for reads of size zero or more */
+		fist_copy_attr_atime(file->f_dentry->d_inode,
+				     hidden_file->f_dentry->d_inode);
+	}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	/*
+	 * MAJOR HACK
+	 * because pread() does not have any way to tell us that it is
+	 * our caller, then we don't know for sure if we have to update
+	 * the file positions.  This hack relies on read() having passed us
+	 * the "real" pointer of its struct file's f_pos field.
+	 */
+	if (ppos == &file->f_pos)
+		hidden_file->f_pos = *ppos = pos;
+	if (hidden_file->f_reada) { /* update readahead information if needed */
+		file->f_reada = hidden_file->f_reada;
+		file->f_ramax = hidden_file->f_ramax;
+		file->f_raend = hidden_file->f_raend;
+		file->f_ralen = hidden_file->f_ralen;
+		file->f_rawin = hidden_file->f_rawin;
+	}
+#else
+	memcpy(&(file->f_ra),&(hidden_file->f_ra),sizeof(struct file_ra_state));
+#endif
+
+ out:
+	return err;
+}
+
+
+/* this mini_fo_write() does not modify data pages! */
+STATIC ssize_t
+mini_fo_write(file_t *file, const char *buf, size_t count, loff_t *ppos)
+{
+	int err = -EINVAL;
+	file_t *hidden_file = NULL;
+	inode_t *inode;
+	inode_t *hidden_inode;
+	loff_t pos = *ppos;
+
+	/* mk: fan out: */
+	if (ftopd(file) != NULL) {
+		if(ftohf2(file)) {
+			hidden_file = ftohf2(file);
+		} else {
+			/* This is bad! We have no storage file to write to. This
+			 * should never happen because if a file is opened for
+			 * writing, a copy should have been made earlier.
+			 */
+			printk(KERN_CRIT "mini_fo: write : ERROR, no storage file to write.\n");
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+	inode = file->f_dentry->d_inode;
+	hidden_inode = itohi2(inode);
+	if(!hidden_inode) {
+		printk(KERN_CRIT "mini_fo: write: no sto inode found, not good.\n");
+		goto out;
+	}
+
+	if (!hidden_file->f_op || !hidden_file->f_op->write)
+		goto out;
+
+	/* adjust for append -- seek to the end of the file */
+	if (file->f_flags & O_APPEND)
+		pos = inode->i_size;
+
+	err = hidden_file->f_op->write(hidden_file, buf, count, &pos);
+
+	/*
+	 * copy ctime and mtime from lower layer attributes
+	 * atime is unchanged for both layers
+	 */
+	if (err >= 0)
+		fist_copy_attr_times(inode, hidden_inode);
+	
+	*ppos = pos;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+	/*
+	 * XXX: MAJOR HACK
+	 *
+	 * because pwrite() does not have any way to tell us that it is
+	 * our caller, then we don't know for sure if we have to update
+	 * the file positions.  This hack relies on write() having passed us
+	 * the "real" pointer of its struct file's f_pos field.
+	 */
+	if (ppos == &file->f_pos)
+		hidden_file->f_pos = *ppos = pos;
+#endif
+	/* update this inode's size */
+	if (pos > inode->i_size)
+		inode->i_size = pos;
+
+ out:
+	return err;
+}
+
+/* Global variable to hold a file_t pointer.
+ * This serves to allow mini_fo_filldir function to know which file is
+ * beeing read, which is required for two reasons:
+ *
+ *   - be able to call wol functions in order to avoid listing deleted
+ *     base files.
+ *   - if we're reading a directory which is in state 1, we need to
+ *     maintain a list (in mini_fo_filldir) of which files allready 
+ *     have been copied to userspace,to detect files existing in base
+ *     and storage and not list them twice.
+ */
+filldir_t mini_fo_filldir_orig;
+file_t *mini_fo_filldir_file;
+
+/* mainly copied from fs/readdir.c */
+STATIC int
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
+mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
+		  u64 ino, unsigned int d_type)
+#else
+mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
+		  ino_t ino, unsigned int d_type)
+#endif
+{
+	struct getdents_callback * buf = (struct getdents_callback *) __buf;
+	file_t* file = mini_fo_filldir_file;
+
+	/* In theses states we filter meta files in storage (WOL) */
+	if(file && (dtopd(file->f_dentry)->state == MODIFIED ||
+		    dtopd(file->f_dentry)->state == CREATED ||
+		    dtopd(file->f_dentry)->state == DEL_REWRITTEN)) {
+
+		int tmp = strlen(META_FILENAME);