[PATCH] ext4: initial copy of files from ext3

Start of the ext4 patch series.  See Documentation/filesystems/ext4.txt for
details.

This is a simple copy of the files in fs/ext3 to fs/ext4 and
/usr/incude/linux/ext3* to /usr/include/ex4*
Signed-off-by: NDave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/ext4/Makefile

+#
+# Makefile for the linux ext3-filesystem routines.
+#
+
+obj-$(CONFIG_EXT3_FS) += ext3.o
+
+ext3-y	:= balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
+	   ioctl.o namei.o super.o symlink.o hash.o resize.o
+
+ext3-$(CONFIG_EXT3_FS_XATTR)	 += xattr.o xattr_user.o xattr_trusted.o
+ext3-$(CONFIG_EXT3_FS_POSIX_ACL) += acl.o
+ext3-$(CONFIG_EXT3_FS_SECURITY)	 += xattr_security.o

fs/ext4/acl.c

+/*
+ * linux/fs/ext3/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/capability.h>
+#include <linux/fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *
+ext3_acl_from_disk(const void *value, size_t size)
+{
+	const char *end = (char *)value + size;
+	int n, count;
+	struct posix_acl *acl;
+
+	if (!value)
+		return NULL;
+	if (size < sizeof(ext3_acl_header))
+		 return ERR_PTR(-EINVAL);
+	if (((ext3_acl_header *)value)->a_version !=
+	    cpu_to_le32(EXT3_ACL_VERSION))
+		return ERR_PTR(-EINVAL);
+	value = (char *)value + sizeof(ext3_acl_header);
+	count = ext3_acl_count(size);
+	if (count < 0)
+		return ERR_PTR(-EINVAL);
+	if (count == 0)
+		return NULL;
+	acl = posix_acl_alloc(count, GFP_KERNEL);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+	for (n=0; n < count; n++) {
+		ext3_acl_entry *entry =
+			(ext3_acl_entry *)value;
+		if ((char *)value + sizeof(ext3_acl_entry_short) > end)
+			goto fail;
+		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
+		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+		switch(acl->a_entries[n].e_tag) {
+			case ACL_USER_OBJ:
+			case ACL_GROUP_OBJ:
+			case ACL_MASK:
+			case ACL_OTHER:
+				value = (char *)value +
+					sizeof(ext3_acl_entry_short);
+				acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
+				break;
+
+			case ACL_USER:
+			case ACL_GROUP:
+				value = (char *)value + sizeof(ext3_acl_entry);
+				if ((char *)value > end)
+					goto fail;
+				acl->a_entries[n].e_id =
+					le32_to_cpu(entry->e_id);
+				break;
+
+			default:
+				goto fail;
+		}
+	}
+	if (value != end)
+		goto fail;
+	return acl;
+
+fail:
+	posix_acl_release(acl);
+	return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *
+ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+	ext3_acl_header *ext_acl;
+	char *e;
+	size_t n;
+
+	*size = ext3_acl_size(acl->a_count);
+	ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
+			sizeof(ext3_acl_entry), GFP_KERNEL);
+	if (!ext_acl)
+		return ERR_PTR(-ENOMEM);
+	ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
+	e = (char *)ext_acl + sizeof(ext3_acl_header);
+	for (n=0; n < acl->a_count; n++) {
+		ext3_acl_entry *entry = (ext3_acl_entry *)e;
+		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
+		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
+		switch(acl->a_entries[n].e_tag) {
+			case ACL_USER:
+			case ACL_GROUP:
+				entry->e_id =
+					cpu_to_le32(acl->a_entries[n].e_id);
+				e += sizeof(ext3_acl_entry);
+				break;
+
+			case ACL_USER_OBJ:
+			case ACL_GROUP_OBJ:
+			case ACL_MASK:
+			case ACL_OTHER:
+				e += sizeof(ext3_acl_entry_short);
+				break;
+
+			default:
+				goto fail;
+		}
+	}
+	return (char *)ext_acl;
+
+fail:
+	kfree(ext_acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static inline struct posix_acl *
+ext3_iget_acl(struct inode *inode, struct posix_acl **i_acl)
+{
+	struct posix_acl *acl = EXT3_ACL_NOT_CACHED;
+
+	spin_lock(&inode->i_lock);
+	if (*i_acl != EXT3_ACL_NOT_CACHED)
+		acl = posix_acl_dup(*i_acl);
+	spin_unlock(&inode->i_lock);
+
+	return acl;
+}
+
+static inline void
+ext3_iset_acl(struct inode *inode, struct posix_acl **i_acl,
+                  struct posix_acl *acl)
+{
+	spin_lock(&inode->i_lock);
+	if (*i_acl != EXT3_ACL_NOT_CACHED)
+		posix_acl_release(*i_acl);
+	*i_acl = posix_acl_dup(acl);
+	spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Inode operation get_posix_acl().
+ *
+ * inode->i_mutex: don't care
+ */
+static struct posix_acl *
+ext3_get_acl(struct inode *inode, int type)
+{
+	struct ext3_inode_info *ei = EXT3_I(inode);
+	int name_index;
+	char *value = NULL;
+	struct posix_acl *acl;
+	int retval;
+
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return NULL;
+
+	switch(type) {
+		case ACL_TYPE_ACCESS:
+			acl = ext3_iget_acl(inode, &ei->i_acl);
+			if (acl != EXT3_ACL_NOT_CACHED)
+				return acl;
+			name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			acl = ext3_iget_acl(inode, &ei->i_default_acl);
+			if (acl != EXT3_ACL_NOT_CACHED)
+				return acl;
+			name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
+			break;
+
+		default:
+			return ERR_PTR(-EINVAL);
+	}
+	retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
+	if (retval > 0) {
+		value = kmalloc(retval, GFP_KERNEL);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		retval = ext3_xattr_get(inode, name_index, "", value, retval);
+	}
+	if (retval > 0)
+		acl = ext3_acl_from_disk(value, retval);
+	else if (retval == -ENODATA || retval == -ENOSYS)
+		acl = NULL;
+	else
+		acl = ERR_PTR(retval);
+	kfree(value);
+
+	if (!IS_ERR(acl)) {
+		switch(type) {
+			case ACL_TYPE_ACCESS:
+				ext3_iset_acl(inode, &ei->i_acl, acl);
+				break;
+
+			case ACL_TYPE_DEFAULT:
+				ext3_iset_acl(inode, &ei->i_default_acl, acl);
+				break;
+		}
+	}
+	return acl;
+}
+
+/*
+ * Set the access or default ACL of an inode.
+ *
+ * inode->i_mutex: down unless called from ext3_new_inode
+ */
+static int
+ext3_set_acl(handle_t *handle, struct inode *inode, int type,
+	     struct posix_acl *acl)
+{
+	struct ext3_inode_info *ei = EXT3_I(inode);
+	int name_index;
+	void *value = NULL;
+	size_t size = 0;
+	int error;
+
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	switch(type) {
+		case ACL_TYPE_ACCESS:
+			name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
+			if (acl) {
+				mode_t mode = inode->i_mode;
+				error = posix_acl_equiv_mode(acl, &mode);
+				if (error < 0)
+					return error;
+				else {
+					inode->i_mode = mode;
+					ext3_mark_inode_dirty(handle, inode);
+					if (error == 0)
+						acl = NULL;
+				}
+			}
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
+			if (!S_ISDIR(inode->i_mode))
+				return acl ? -EACCES : 0;
+			break;
+
+		default:
+			return -EINVAL;
+	}
+	if (acl) {
+		value = ext3_acl_to_disk(acl, &size);
+		if (IS_ERR(value))
+			return (int)PTR_ERR(value);
+	}
+
+	error = ext3_xattr_set_handle(handle, inode, name_index, "",
+				      value, size, 0);
+
+	kfree(value);
+	if (!error) {
+		switch(type) {
+			case ACL_TYPE_ACCESS:
+				ext3_iset_acl(inode, &ei->i_acl, acl);
+				break;
+
+			case ACL_TYPE_DEFAULT:
+				ext3_iset_acl(inode, &ei->i_default_acl, acl);
+				break;
+		}
+	}
+	return error;
+}
+
+static int
+ext3_check_acl(struct inode *inode, int mask)
+{
+	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl) {
+		int error = posix_acl_permission(inode, acl, mask);
+		posix_acl_release(acl);
+		return error;
+	}
+
+	return -EAGAIN;
+}
+
+int
+ext3_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+	return generic_permission(inode, mask, ext3_check_acl);
+}
+
+/*
+ * Initialize the ACLs of a new inode. Called from ext3_new_inode.
+ *
+ * dir->i_mutex: down
+ * inode->i_mutex: up (access to inode is still exclusive)
+ */
+int
+ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *acl = NULL;
+	int error = 0;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		if (test_opt(dir->i_sb, POSIX_ACL)) {
+			acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
+			if (IS_ERR(acl))
+				return PTR_ERR(acl);
+		}
+		if (!acl)
+			inode->i_mode &= ~current->fs->umask;
+	}
+	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
+		struct posix_acl *clone;
+		mode_t mode;
+
+		if (S_ISDIR(inode->i_mode)) {
+			error = ext3_set_acl(handle, inode,
+					     ACL_TYPE_DEFAULT, acl);
+			if (error)
+				goto cleanup;
+		}
+		clone = posix_acl_clone(acl, GFP_KERNEL);
+		error = -ENOMEM;
+		if (!clone)
+			goto cleanup;
+
+		mode = inode->i_mode;
+		error = posix_acl_create_masq(clone, &mode);
+		if (error >= 0) {
+			inode->i_mode = mode;
+			if (error > 0) {
+				/* This is an extended ACL */
+				error = ext3_set_acl(handle, inode,
+						     ACL_TYPE_ACCESS, clone);
+			}
+		}
+		posix_acl_release(clone);
+	}
+cleanup:
+	posix_acl_release(acl);
+	return error;
+}
+
+/*
+ * Does chmod for an inode that may have an Access Control List. The
+ * inode->i_mode field must be updated to the desired value by the caller
+ * before calling this function.
+ * Returns 0 on success, or a negative error number.
+ *
+ * We change the ACL rather than storing some ACL entries in the file
+ * mode permission bits (which would be more efficient), because that
+ * would break once additional permissions (like  ACL_APPEND, ACL_DELETE
+ * for directories) are added. There are no more bits available in the
+ * file mode.
+ *
+ * inode->i_mutex: down
+ */
+int
+ext3_acl_chmod(struct inode *inode)
+{
+	struct posix_acl *acl, *clone;
+        int error;
+
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return 0;
+	acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
+	if (IS_ERR(acl) || !acl)
+		return PTR_ERR(acl);
+	clone = posix_acl_clone(acl, GFP_KERNEL);
+	posix_acl_release(acl);
+	if (!clone)
+		return -ENOMEM;
+	error = posix_acl_chmod_masq(clone, inode->i_mode);
+	if (!error) {
+		handle_t *handle;
+		int retries = 0;
+
+	retry:
+		handle = ext3_journal_start(inode,
+				EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
+		if (IS_ERR(handle)) {
+			error = PTR_ERR(handle);
+			ext3_std_error(inode->i_sb, error);
+			goto out;
+		}
+		error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
+		ext3_journal_stop(handle);
+		if (error == -ENOSPC &&
+		    ext3_should_retry_alloc(inode->i_sb, &retries))
+			goto retry;
+	}
+out:
+	posix_acl_release(clone);
+	return error;
+}
+
+/*
+ * Extended attribute handlers
+ */
+static size_t
+ext3_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
+			   const char *name, size_t name_len)
+{
+	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
+
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return 0;
+	if (list && size <= list_len)
+		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
+	return size;
+}
+
+static size_t
+ext3_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
+			    const char *name, size_t name_len)
+{
+	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
+
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return 0;
+	if (list && size <= list_len)
+		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
+	return size;
+}
+
+static int
+ext3_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
+{
+	struct posix_acl *acl;
+	int error;
+
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return -EOPNOTSUPP;
+
+	acl = ext3_get_acl(inode, type);
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl == NULL)
+		return -ENODATA;
+	error = posix_acl_to_xattr(acl, buffer, size);
+	posix_acl_release(acl);
+
+	return error;
+}
+
+static int
+ext3_xattr_get_acl_access(struct inode *inode, const char *name,
+			  void *buffer, size_t size)
+{
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
+}
+
+static int
+ext3_xattr_get_acl_default(struct inode *inode, const char *name,
+			   void *buffer, size_t size)
+{
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
+}
+
+static int
+ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
+		   size_t size)
+{
+	handle_t *handle;
+	struct posix_acl *acl;
+	int error, retries = 0;
+
+	if (!test_opt(inode->i_sb, POSIX_ACL))
+		return -EOPNOTSUPP;
+	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+		return -EPERM;
+
+	if (value) {
+		acl = posix_acl_from_xattr(value, size);
+		if (IS_ERR(acl))
+			return PTR_ERR(acl);
+		else if (acl) {
+			error = posix_acl_valid(acl);
+			if (error)
+				goto release_and_out;
+		}
+	} else
+		acl = NULL;
+
+retry:
+	handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	error = ext3_set_acl(handle, inode, type, acl);
+	ext3_journal_stop(handle);
+	if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
+		goto retry;
+
+release_and_out:
+	posix_acl_release(acl);
+	return error;
+}
+
+static int
+ext3_xattr_set_acl_access(struct inode *inode, const char *name,
+			  const void *value, size_t size, int flags)
+{
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
+}
+
+static int
+ext3_xattr_set_acl_default(struct inode *inode, const char *name,
+			   const void *value, size_t size, int flags)
+{
+	if (strcmp(name, "") != 0)
+		return -EINVAL;
+	return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
+}
+
+struct xattr_handler ext3_xattr_acl_access_handler = {
+	.prefix	= POSIX_ACL_XATTR_ACCESS,
+	.list	= ext3_xattr_list_acl_access,
+	.get	= ext3_xattr_get_acl_access,
+	.set	= ext3_xattr_set_acl_access,
+};
+
+struct xattr_handler ext3_xattr_acl_default_handler = {
+	.prefix	= POSIX_ACL_XATTR_DEFAULT,
+	.list	= ext3_xattr_list_acl_default,
+	.get	= ext3_xattr_get_acl_default,
+	.set	= ext3_xattr_set_acl_default,
+};

fs/ext4/acl.h

+/*
+  File: fs/ext3/acl.h
+
+  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/posix_acl_xattr.h>
+
+#define EXT3_ACL_VERSION	0x0001
+
+typedef struct {
+	__le16		e_tag;
+	__le16		e_perm;
+	__le32		e_id;
+} ext3_acl_entry;
+
+typedef struct {
+	__le16		e_tag;
+	__le16		e_perm;
+} ext3_acl_entry_short;
+
+typedef struct {
+	__le32		a_version;
+} ext3_acl_header;
+
+static inline size_t ext3_acl_size(int count)
+{
+	if (count <= 4) {
+		return sizeof(ext3_acl_header) +
+		       count * sizeof(ext3_acl_entry_short);
+	} else {
+		return sizeof(ext3_acl_header) +
+		       4 * sizeof(ext3_acl_entry_short) +
+		       (count - 4) * sizeof(ext3_acl_entry);
+	}
+}
+
+static inline int ext3_acl_count(size_t size)
+{
+	ssize_t s;
+	size -= sizeof(ext3_acl_header);
+	s = size - 4 * sizeof(ext3_acl_entry_short);
+	if (s < 0) {
+		if (size % sizeof(ext3_acl_entry_short))
+			return -1;
+		return size / sizeof(ext3_acl_entry_short);
+	} else {
+		if (s % sizeof(ext3_acl_entry))
+			return -1;
+		return s / sizeof(ext3_acl_entry) + 4;
+	}
+}
+
+#ifdef CONFIG_EXT3_FS_POSIX_ACL
+
+/* Value for inode->u.ext3_i.i_acl and inode->u.ext3_i.i_default_acl
+   if the ACL has not been cached */
+#define EXT3_ACL_NOT_CACHED ((void *)-1)
+
+/* acl.c */
+extern int ext3_permission (struct inode *, int, struct nameidata *);
+extern int ext3_acl_chmod (struct inode *);
+extern int ext3_init_acl (handle_t *, struct inode *, struct inode *);
+
+#else  /* CONFIG_EXT3_FS_POSIX_ACL */
+#include <linux/sched.h>
+#define ext3_permission NULL
+
+static inline int
+ext3_acl_chmod(struct inode *inode)
+{
+	return 0;
+}
+
+static inline int
+ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+	return 0;
+}
+#endif  /* CONFIG_EXT3_FS_POSIX_ACL */
+

fs/ext4/bitmap.c

+/*
+ *  linux/fs/ext3/bitmap.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+
+#ifdef EXT3FS_DEBUG
+
+static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
+
+unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
+{
+	unsigned int i;
+	unsigned long sum = 0;
+
+	if (!map)
+		return (0);
+	for (i = 0; i < numchars; i++)
+		sum += nibblemap[map->b_data[i] & 0xf] +
+			nibblemap[(map->b_data[i] >> 4) & 0xf];
+	return (sum);
+}
+
+#endif  /*  EXT3FS_DEBUG  */
+

fs/ext4/dir.c

+/*
+ *  linux/fs/ext3/dir.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/dir.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 directory handling functions
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * Hash Tree Directory indexing (c) 2001  Daniel Phillips
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+
+static unsigned char ext3_filetype_table[] = {
+	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int ext3_readdir(struct file *, void *, filldir_t);
+static int ext3_dx_readdir(struct file * filp,
+			   void * dirent, filldir_t filldir);
+static int ext3_release_dir (struct inode * inode,
+				struct file * filp);
+
+const struct file_operations ext3_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.readdir	= ext3_readdir,		/* we take BKL. needed?*/
+	.ioctl		= ext3_ioctl,		/* BKL held */
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ext3_compat_ioctl,
+#endif
+	.fsync		= ext3_sync_file,	/* BKL held */
+#ifdef CONFIG_EXT3_INDEX
+	.release	= ext3_release_dir,
+#endif
+};
+
+
+static unsigned char get_dtype(struct super_block *sb, int filetype)
+{
+	if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_FILETYPE) ||
+	    (filetype >= EXT3_FT_MAX))
+		return DT_UNKNOWN;
+
+	return (ext3_filetype_table[filetype]);
+}
+
+
+int ext3_check_dir_entry (const char * function, struct inode * dir,
+			  struct ext3_dir_entry_2 * de,
+			  struct buffer_head * bh,
+			  unsigned long offset)
+{
+	const char * error_msg = NULL;
+	const int rlen = le16_to_cpu(de->rec_len);
+
+	if (rlen < EXT3_DIR_REC_LEN(1))
+		error_msg = "rec_len is smaller than minimal";
+	else if (rlen % 4 != 0)
+		error_msg = "rec_len % 4 != 0";
+	else if (rlen < EXT3_DIR_REC_LEN(de->name_len))
+		error_msg = "rec_len is too small for name_len";
+	else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
+		error_msg = "directory entry across blocks";
+	else if (le32_to_cpu(de->inode) >
+			le32_to_cpu(EXT3_SB(dir->i_sb)->s_es->s_inodes_count))
+		error_msg = "inode out of bounds";
+
+	if (error_msg != NULL)
+		ext3_error (dir->i_sb, function,
+			"bad entry in directory #%lu: %s - "
+			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error_msg, offset,
+			(unsigned long) le32_to_cpu(de->inode),
+			rlen, de->name_len);
+	return error_msg == NULL ? 1 : 0;
+}
+
+static int ext3_readdir(struct file * filp,
+			 void * dirent, filldir_t filldir)
+{
+	int error = 0;
+	unsigned long offset;
+	int i, stored;
+	struct ext3_dir_entry_2 *de;
+	struct super_block *sb;
+	int err;
+	struct inode *inode = filp->f_dentry->d_inode;
+	int ret = 0;
+
+	sb = inode->i_sb;
+
+#ifdef CONFIG_EXT3_INDEX
+	if (EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
+				    EXT3_FEATURE_COMPAT_DIR_INDEX) &&
+	    ((EXT3_I(inode)->i_flags & EXT3_INDEX_FL) ||
+	     ((inode->i_size >> sb->s_blocksize_bits) == 1))) {
+		err = ext3_dx_readdir(filp, dirent, filldir);
+		if (err != ERR_BAD_DX_DIR) {
+			ret = err;
+			goto out;
+		}
+		/*
+		 * We don't set the inode dirty flag since it's not
+		 * critical that it get flushed back to the disk.
+		 */
+		EXT3_I(filp->f_dentry->d_inode)->i_flags &= ~EXT3_INDEX_FL;
+	}
+#endif
+	stored = 0;
+	offset = filp->f_pos & (sb->s_blocksize - 1);
+
+	while (!error && !stored && filp->f_pos < inode->i_size) {
+		unsigned long blk = filp->f_pos >> EXT3_BLOCK_SIZE_BITS(sb);
+		struct buffer_head map_bh;
+		struct buffer_head *bh = NULL;
+
+		map_bh.b_state = 0;
+		err = ext3_get_blocks_handle(NULL, inode, blk, 1,
+						&map_bh, 0, 0);
+		if (err > 0) {
+			page_cache_readahead(sb->s_bdev->bd_inode->i_mapping,
+				&filp->f_ra,
+				filp,
+				map_bh.b_blocknr >>
+					(PAGE_CACHE_SHIFT - inode->i_blkbits),
+				1);
+			bh = ext3_bread(NULL, inode, blk, 0, &err);
+		}
+
+		/*
+		 * We ignore I/O errors on directories so users have a chance
+		 * of recovering data when there's a bad sector
+		 */
+		if (!bh) {
+			ext3_error (sb, "ext3_readdir",
+				"directory #%lu contains a hole at offset %lu",
+				inode->i_ino, (unsigned long)filp->f_pos);
+			filp->f_pos += sb->s_blocksize - offset;
+			continue;
+		}
+
+revalidate:
+		/* If the dir block has changed since the last call to
+		 * readdir(2), then we might be pointing to an invalid
+		 * dirent right now.  Scan from the start of the block
+		 * to make sure. */
+		if (filp->f_version != inode->i_version) {
+			for (i = 0; i < sb->s_blocksize && i < offset; ) {
+				de = (struct ext3_dir_entry_2 *)
+					(bh->b_data + i);
+				/* It's too expensive to do a full
+				 * dirent test each time round this
+				 * loop, but we do have to test at
+				 * least that it is non-zero.  A
+				 * failure will be detected in the
+				 * dirent test below. */
+				if (le16_to_cpu(de->rec_len) <
+						EXT3_DIR_REC_LEN(1))
+					break;
+				i += le16_to_cpu(de->rec_len);
+			}
+			offset = i;
+			filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
+				| offset;
+			filp->f_version = inode->i_version;
+		}
+
+		while (!error && filp->f_pos < inode->i_size
+		       && offset < sb->s_blocksize) {
+			de = (struct ext3_dir_entry_2 *) (bh->b_data + offset);
+			if (!ext3_check_dir_entry ("ext3_readdir", inode, de,
+						   bh, offset)) {
+				/* On error, skip the f_pos to the
+                                   next block. */
+				filp->f_pos = (filp->f_pos |
+						(sb->s_blocksize - 1)) + 1;
+				brelse (bh);
+				ret = stored;
+				goto out;
+			}
+			offset += le16_to_cpu(de->rec_len);
+			if (le32_to_cpu(de->inode)) {
+				/* We might block in the next section
+				 * if the data destination is
+				 * currently swapped out.  So, use a
+				 * version stamp to detect whether or
+				 * not the directory has been modified
+				 * during the copy operation.
+				 */
+				unsigned long version = filp->f_version;
+
+				error = filldir(dirent, de->name,
+						de->name_len,
+						filp->f_pos,
+						le32_to_cpu(de->inode),
+						get_dtype(sb, de->file_type));
+				if (error)
+					break;
+				if (version != filp->f_version)
+					goto revalidate;
+				stored ++;
+			}
+			filp->f_pos += le16_to_cpu(de->rec_len);
+		}
+		offset = 0;
+		brelse (bh);
+	}
+out:
+	return ret;
+}
+
+#ifdef CONFIG_EXT3_INDEX
+/*
+ * These functions convert from the major/minor hash to an f_pos
+ * value.
+ *
+ * Currently we only use major hash numer.  This is unfortunate, but
+ * on 32-bit machines, the same VFS interface is used for lseek and
+ * llseek, so if we use the 64 bit offset, then the 32-bit versions of
+ * lseek/telldir/seekdir will blow out spectacularly, and from within
+ * the ext2 low-level routine, we don't know if we're being called by
+ * a 64-bit version of the system call or the 32-bit version of the
+ * system call.  Worse yet, NFSv2 only allows for a 32-bit readdir
+ * cookie.  Sigh.
+ */
+#define hash2pos(major, minor)	(major >> 1)
+#define pos2maj_hash(pos)	((pos << 1) & 0xffffffff)
+#define pos2min_hash(pos)	(0)
+
+/*
+ * This structure holds the nodes of the red-black tree used to store
+ * the directory entry in hash order.
+ */
+struct fname {
+	__u32		hash;
+	__u32		minor_hash;
+	struct rb_node	rb_hash;
+	struct fname	*next;
+	__u32		inode;
+	__u8		name_len;
+	__u8		file_type;
+	char		name[0];
+};
+
+/*
+ * This functoin implements a non-recursive way of freeing all of the
+ * nodes in the red-black tree.
+ */
+static void free_rb_tree_fname(struct rb_root *root)
+{
+	struct rb_node	*n = root->rb_node;
+	struct rb_node	*parent;
+	struct fname	*fname;
+
+	while (n) {
+		/* Do the node's children first */
+		if ((n)->rb_left) {
+			n = n->rb_left;
+			continue;
+		}
+		if (n->rb_right) {
+			n = n->rb_right;
+			continue;
+		}
+		/*
+		 * The node has no children; free it, and then zero
+		 * out parent's link to it.  Finally go to the
+		 * beginning of the loop and try to free the parent
+		 * node.
+		 */
+		parent = rb_parent(n);
+		fname = rb_entry(n, struct fname, rb_hash);
+		while (fname) {
+			struct fname * old = fname;
+			fname = fname->next;
+			kfree (old);
+		}
+		if (!parent)
+			root->rb_node = NULL;
+		else if (parent->rb_left == n)
+			parent->rb_left = NULL;
+		else if (parent->rb_right == n)
+			parent->rb_right = NULL;
+		n = parent;
+	}
+	root->rb_node = NULL;
+}
+
+
+static struct dir_private_info *create_dir_info(loff_t pos)
+{
+	struct dir_private_info *p;
+
+	p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL);
+	if (!p)
+		return NULL;
+	p->root.rb_node = NULL;
+	p->curr_node = NULL;
+	p->extra_fname = NULL;
+	p->last_pos = 0;
+	p->curr_hash = pos2maj_hash(pos);
+	p->curr_minor_hash = pos2min_hash(pos);
+	p->next_hash = 0;
+	return p;
+}
+
+void ext3_htree_free_dir_info(struct dir_private_info *p)
+{
+	free_rb_tree_fname(&p->root);
+	kfree(p);
+}
+
+/*
+ * Given a directory entry, enter it into the fname rb tree.
+ */
+int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
+			     __u32 minor_hash,
+			     struct ext3_dir_entry_2 *dirent)
+{
+	struct rb_node **p, *parent = NULL;
+	struct fname * fname, *new_fn;
+	struct dir_private_info *info;
+	int len;
+
+	info = (struct dir_private_info *) dir_file->private_data;
+	p = &info->root.rb_node;
+
+	/* Create and allocate the fname structure */
+	len = sizeof(struct fname) + dirent->name_len + 1;
+	new_fn = kzalloc(len, GFP_KERNEL);
+	if (!new_fn)
+		return -ENOMEM;
+	new_fn->hash = hash;
+	new_fn->minor_hash = minor_hash;
+	new_fn->inode = le32_to_cpu(dirent->inode);
+	new_fn->name_len = dirent->name_len;
+	new_fn->file_type = dirent->file_type;
+	memcpy(new_fn->name, dirent->name, dirent->name_len);
+	new_fn->name[dirent->name_len] = 0;
+
+	while (*p) {
+		parent = *p;
+		fname = rb_entry(parent, struct fname, rb_hash);
+
+		/*
+		 * If the hash and minor hash match up, then we put
+		 * them on a linked list.  This rarely happens...
+		 */
+		if ((new_fn->hash == fname->hash) &&
+		    (new_fn->minor_hash == fname->minor_hash)) {
+			new_fn->next = fname->next;
+			fname->next = new_fn;
+			return 0;
+		}
+
+		if (new_fn->hash < fname->hash)
+			p = &(*p)->rb_left;
+		else if (new_fn->hash > fname->hash)
+			p = &(*p)->rb_right;
+		else if (new_fn->minor_hash < fname->minor_hash)
+			p = &(*p)->rb_left;
+		else /* if (new_fn->minor_hash > fname->minor_hash) */
+			p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&new_fn->rb_hash, parent, p);
+	rb_insert_color(&new_fn->rb_hash, &info->root);
+	return 0;
+}
+
+
+
+/*
+ * This is a helper function for ext3_dx_readdir.  It calls filldir
+ * for all entres on the fname linked list.  (Normally there is only
+ * one entry on the linked list, unless there are 62 bit hash collisions.)
+ */
+static int call_filldir(struct file * filp, void * dirent,
+			filldir_t filldir, struct fname *fname)
+{
+	struct dir_private_info *info = filp->private_data;
+	loff_t	curr_pos;
+	struct inode *inode = filp->f_dentry->d_inode;
+	struct super_block * sb;
+	int error;
+
+	sb = inode->i_sb;
+
+	if (!fname) {
+		printk("call_filldir: called with null fname?!?\n");
+		return 0;
+	}
+	curr_pos = hash2pos(fname->hash, fname->minor_hash);
+	while (fname) {
+		error = filldir(dirent, fname->name,
+				fname->name_len, curr_pos,
+				fname->inode,
+				get_dtype(sb, fname->file_type));
+		if (error) {
+			filp->f_pos = curr_pos;
+			info->extra_fname = fname->next;
+			return error;
+		}
+		fname = fname->next;
+	}
+	return 0;
+}
+
+static int ext3_dx_readdir(struct file * filp,
+			 void * dirent, filldir_t filldir)
+{
+	struct dir_private_info *info = filp->private_data;
+	struct inode *inode = filp->f_dentry->d_inode;
+	struct fname *fname;
+	int	ret;
+
+	if (!info) {
+		info = create_dir_info(filp->f_pos);
+		if (!info)
+			return -ENOMEM;
+		filp->private_data = info;
+	}
+
+	if (filp->f_pos == EXT3_HTREE_EOF)
+		return 0;	/* EOF */
+
+	/* Some one has messed with f_pos; reset the world */
+	if (info->last_pos != filp->f_pos) {
+		free_rb_tree_fname(&info->root);
+		info->curr_node = NULL;
+		info->extra_fname = NULL;
+		info->curr_hash = pos2maj_hash(filp->f_pos);
+		info->curr_minor_hash = pos2min_hash(filp->f_pos);
+	}
+
+	/*
+	 * If there are any leftover names on the hash collision
+	 * chain, return them first.
+	 */
+	if (info->extra_fname &&
+	    call_filldir(filp, dirent, filldir, info->extra_fname))
+		goto finished;
+
+	if (!info->curr_node)
+		info->curr_node = rb_first(&info->root);
+
+	while (1) {
+		/*
+		 * Fill the rbtree if we have no more entries,
+		 * or the inode has changed since we last read in the
+		 * cached entries.
+		 */
+		if ((!info->curr_node) ||
+		    (filp->f_version != inode->i_version)) {
+			info->curr_node = NULL;
+			free_rb_tree_fname(&info->root);
+			filp->f_version = inode->i_version;
+			ret = ext3_htree_fill_tree(filp, info->curr_hash,
+						   info->curr_minor_hash,
+						   &info->next_hash);
+			if (ret < 0)
+				return ret;
+			if (ret == 0) {
+				filp->f_pos = EXT3_HTREE_EOF;
+				break;
+			}
+			info->curr_node = rb_first(&info->root);
+		}
+
+		fname = rb_entry(info->curr_node, struct fname, rb_hash);
+		info->curr_hash = fname->hash;
+		info->curr_minor_hash = fname->minor_hash;
+		if (call_filldir(filp, dirent, filldir, fname))
+			break;
+
+		info->curr_node = rb_next(info->curr_node);
+		if (!info->curr_node) {
+			if (info->next_hash == ~0) {
+				filp->f_pos = EXT3_HTREE_EOF;
+				break;
+			}
+			info->curr_hash = info->next_hash;
+			info->curr_minor_hash = 0;
+		}
+	}
+finished:
+	info->last_pos = filp->f_pos;
+	return 0;
+}
+
+static int ext3_release_dir (struct inode * inode, struct file * filp)
+{
+       if (filp->private_data)
+		ext3_htree_free_dir_info(filp->private_data);
+
+	return 0;
+}
+
+#endif

fs/ext4/file.c

+/*
+ *  linux/fs/ext3/file.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/file.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 fs regular file handling primitives
+ *
+ *  64-bit file support on 64-bit platforms by Jakub Jelinek
+ *	(jj@sunsite.ms.mff.cuni.cz)
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Called when an inode is released. Note that this is different
+ * from ext3_file_open: open gets called at every open, but release
+ * gets called only when /all/ the files are closed.
+ */
+static int ext3_release_file (struct inode * inode, struct file * filp)
+{
+	/* if we are the last writer on the inode, drop the block reservation */
+	if ((filp->f_mode & FMODE_WRITE) &&
+			(atomic_read(&inode->i_writecount) == 1))
+	{
+		mutex_lock(&EXT3_I(inode)->truncate_mutex);
+		ext3_discard_reservation(inode);
+		mutex_unlock(&EXT3_I(inode)->truncate_mutex);
+	}
+	if (is_dx(inode) && filp->private_data)
+		ext3_htree_free_dir_info(filp->private_data);
+
+	return 0;
+}
+
+static ssize_t
+ext3_file_write(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_dentry->d_inode;
+	ssize_t ret;
+	int err;
+
+	ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+
+	/*
+	 * Skip flushing if there was an error, or if nothing was written.
+	 */
+	if (ret <= 0)
+		return ret;
+
+	/*
+	 * If the inode is IS_SYNC, or is O_SYNC and we are doing data
+	 * journalling then we need to make sure that we force the transaction
+	 * to disk to keep all metadata uptodate synchronously.
+	 */
+	if (file->f_flags & O_SYNC) {
+		/*
+		 * If we are non-data-journaled, then the dirty data has
+		 * already been flushed to backing store by generic_osync_inode,
+		 * and the inode has been flushed too if there have been any
+		 * modifications other than mere timestamp updates.
+		 *
+		 * Open question --- do we care about flushing timestamps too
+		 * if the inode is IS_SYNC?
+		 */
+		if (!ext3_should_journal_data(inode))
+			return ret;
+
+		goto force_commit;
+	}
+
+	/*
+	 * So we know that there has been no forced data flush.  If the inode
+	 * is marked IS_SYNC, we need to force one ourselves.
+	 */
+	if (!IS_SYNC(inode))
+		return ret;
+
+	/*
+	 * Open question #2 --- should we force data to disk here too?  If we
+	 * don't, the only impact is that data=writeback filesystems won't
+	 * flush data to disk automatically on IS_SYNC, only metadata (but
+	 * historically, that is what ext2 has done.)
+	 */
+
+force_commit:
+	err = ext3_force_commit(inode->i_sb);
+	if (err)
+		return err;
+	return ret;
+}
+
+const struct file_operations ext3_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= do_sync_read,
+	.write		= do_sync_write,
+	.aio_read	= generic_file_aio_read,
+	.aio_write	= ext3_file_write,
+	.ioctl		= ext3_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ext3_compat_ioctl,
+#endif
+	.mmap		= generic_file_mmap,
+	.open		= generic_file_open,
+	.release	= ext3_release_file,
+	.fsync		= ext3_sync_file,
+	.sendfile	= generic_file_sendfile,
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= generic_file_splice_write,
+};
+
+struct inode_operations ext3_file_inode_operations = {
+	.truncate	= ext3_truncate,
+	.setattr	= ext3_setattr,
+#ifdef CONFIG_EXT3_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext3_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+	.permission	= ext3_permission,
+};
+

fs/ext4/fsync.c

+/*
+ *  linux/fs/ext3/fsync.c
+ *
+ *  Copyright (C) 1993  Stephen Tweedie (sct@redhat.com)
+ *  from
+ *  Copyright (C) 1992  Remy Card (card@masi.ibp.fr)
+ *                      Laboratoire MASI - Institut Blaise Pascal
+ *                      Universite Pierre et Marie Curie (Paris VI)
+ *  from
+ *  linux/fs/minix/truncate.c   Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3fs fsync primitive
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ *  Removed unnecessary code duplication for little endian machines
+ *  and excessive __inline__s.
+ *        Andi Kleen, 1997
+ *
+ * Major simplications and cleanup - we only need to do the metadata, because
+ * we can depend on generic_block_fdatasync() to sync the data blocks.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/writeback.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+
+/*
+ * akpm: A new design for ext3_sync_file().
+ *
+ * This is only called from sys_fsync(), sys_fdatasync() and sys_msync().
+ * There cannot be a transaction open by this task.
+ * Another task could have dirtied this inode.  Its data can be in any
+ * state in the journalling system.
+ *
+ * What we do is just kick off a commit and wait on it.  This will snapshot the
+ * inode to disk.
+ */
+
+int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)
+{
+	struct inode *inode = dentry->d_inode;
+	int ret = 0;
+
+	J_ASSERT(ext3_journal_current_handle() == 0);
+
+	/*
+	 * data=writeback:
+	 *  The caller's filemap_fdatawrite()/wait will sync the data.
+	 *  sync_inode() will sync the metadata
+	 *
+	 * data=ordered:
+	 *  The caller's filemap_fdatawrite() will write the data and
+	 *  sync_inode() will write the inode if it is dirty.  Then the caller's
+	 *  filemap_fdatawait() will wait on the pages.
+	 *
+	 * data=journal:
+	 *  filemap_fdatawrite won't do anything (the buffers are clean).
+	 *  ext3_force_commit will write the file data into the journal and
+	 *  will wait on that.
+	 *  filemap_fdatawait() will encounter a ton of newly-dirtied pages
+	 *  (they were dirtied by commit).  But that's OK - the blocks are
+	 *  safe in-journal, which is all fsync() needs to ensure.
+	 */
+	if (ext3_should_journal_data(inode)) {
+		ret = ext3_force_commit(inode->i_sb);
+		goto out;
+	}
+
+	/*
+	 * The VFS has written the file data.  If the inode is unaltered
+	 * then we need not start a commit.
+	 */
+	if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) {
+		struct writeback_control wbc = {
+			.sync_mode = WB_SYNC_ALL,
+			.nr_to_write = 0, /* sys_fsync did this */
+		};
+		ret = sync_inode(inode, &wbc);
+	}
+out:
+	return ret;
+}

fs/ext4/hash.c

+/*
+ *  linux/fs/ext3/hash.c
+ *
+ * Copyright (C) 2002 by Theodore Ts'o
+ *
+ * This file is released under the GPL v2.
+ *
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/sched.h>
+#include <linux/ext3_fs.h>
+#include <linux/cryptohash.h>
+
+#define DELTA 0x9E3779B9
+
+static void TEA_transform(__u32 buf[4], __u32 const in[])
+{
+	__u32	sum = 0;
+	__u32	b0 = buf[0], b1 = buf[1];
+	__u32	a = in[0], b = in[1], c = in[2], d = in[3];
+	int	n = 16;
+
+	do {
+		sum += DELTA;
+		b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
+		b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
+	} while(--n);
+
+	buf[0] += b0;
+	buf[1] += b1;
+}
+
+
+/* The old legacy hash */
+static __u32 dx_hack_hash (const char *name, int len)
+{
+	__u32 hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9;
+	while (len--) {
+		__u32 hash = hash1 + (hash0 ^ (*name++ * 7152373));
+
+		if (hash & 0x80000000) hash -= 0x7fffffff;
+		hash1 = hash0;
+		hash0 = hash;
+	}
+	return (hash0 << 1);
+}
+
+static void str2hashbuf(const char *msg, int len, __u32 *buf, int num)
+{
+	__u32	pad, val;
+	int	i;
+
+	pad = (__u32)len | ((__u32)len << 8);
+	pad |= pad << 16;
+
+	val = pad;
+	if (len > num*4)
+		len = num * 4;
+	for (i=0; i < len; i++) {
+		if ((i % 4) == 0)
+			val = pad;
+		val = msg[i] + (val << 8);
+		if ((i % 4) == 3) {
+			*buf++ = val;
+			val = pad;
+			num--;
+		}
+	}
+	if (--num >= 0)
+		*buf++ = val;
+	while (--num >= 0)
+		*buf++ = pad;
+}
+
+/*
+ * Returns the hash of a filename.  If len is 0 and name is NULL, then
+ * this function can be used to test whether or not a hash version is
+ * supported.
+ *
+ * The seed is an 4 longword (32 bits) "secret" which can be used to
+ * uniquify a hash.  If the seed is all zero's, then some default seed
+ * may be used.
+ *
+ * A particular hash version specifies whether or not the seed is
+ * represented, and whether or not the returned hash is 32 bits or 64
+ * bits.  32 bit hashes will return 0 for the minor hash.
+ */
+int ext3fs_dirhash(const char *name, int len, struct dx_hash_info *hinfo)
+{
+	__u32	hash;
+	__u32	minor_hash = 0;
+	const char	*p;
+	int		i;
+	__u32		in[8], buf[4];
+
+	/* Initialize the default seed for the hash checksum functions */
+	buf[0] = 0x67452301;
+	buf[1] = 0xefcdab89;
+	buf[2] = 0x98badcfe;
+	buf[3] = 0x10325476;
+
+	/* Check to see if the seed is all zero's */
+	if (hinfo->seed) {
+		for (i=0; i < 4; i++) {
+			if (hinfo->seed[i])
+				break;
+		}
+		if (i < 4)
+			memcpy(buf, hinfo->seed, sizeof(buf));
+	}
+
+	switch (hinfo->hash_version) {
+	case DX_HASH_LEGACY:
+		hash = dx_hack_hash(name, len);
+		break;
+	case DX_HASH_HALF_MD4:
+		p = name;
+		while (len > 0) {
+			str2hashbuf(p, len, in, 8);
+			half_md4_transform(buf, in);
+			len -= 32;
+			p += 32;
+		}
+		minor_hash = buf[2];
+		hash = buf[1];
+		break;
+	case DX_HASH_TEA:
+		p = name;
+		while (len > 0) {
+			str2hashbuf(p, len, in, 4);
+			TEA_transform(buf, in);
+			len -= 16;
+			p += 16;
+		}
+		hash = buf[0];
+		minor_hash = buf[1];
+		break;
+	default:
+		hinfo->hash = 0;
+		return -1;
+	}
+	hash = hash & ~1;
+	if (hash == (EXT3_HTREE_EOF << 1))
+		hash = (EXT3_HTREE_EOF-1) << 1;
+	hinfo->hash = hash;
+	hinfo->minor_hash = minor_hash;
+	return 0;
+}

fs/ext4/ioctl.c

+/*
+ * linux/fs/ext3/ioctl.c
+ *
+ * Copyright (C) 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/capability.h>
+#include <linux/ext3_fs.h>
+#include <linux/ext3_jbd.h>
+#include <linux/time.h>
+#include <linux/compat.h>
+#include <linux/smp_lock.h>
+#include <asm/uaccess.h>
+
+int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
+		unsigned long arg)
+{
+	struct ext3_inode_info *ei = EXT3_I(inode);
+	unsigned int flags;
+	unsigned short rsv_window_size;
+
+	ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
+
+	switch (cmd) {
+	case EXT3_IOC_GETFLAGS:
+		flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
+		return put_user(flags, (int __user *) arg);
+	case EXT3_IOC_SETFLAGS: {
+		handle_t *handle = NULL;
+		int err;
+		struct ext3_iloc iloc;
+		unsigned int oldflags;
+		unsigned int jflag;
+
+		if (IS_RDONLY(inode))
+			return -EROFS;
+
+		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+			return -EACCES;
+
+		if (get_user(flags, (int __user *) arg))
+			return -EFAULT;
+
+		if (!S_ISDIR(inode->i_mode))
+			flags &= ~EXT3_DIRSYNC_FL;
+
+		mutex_lock(&inode->i_mutex);
+		oldflags = ei->i_flags;
+
+		/* The JOURNAL_DATA flag is modifiable only by root */
+		jflag = flags & EXT3_JOURNAL_DATA_FL;
+
+		/*
+		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+		 * the relevant capability.
+		 *
+		 * This test looks nicer. Thanks to Pauline Middelink
+		 */
+		if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
+			if (!capable(CAP_LINUX_IMMUTABLE)) {
+				mutex_unlock(&inode->i_mutex);
+				return -EPERM;
+			}
+		}
+
+		/*
+		 * The JOURNAL_DATA flag can only be changed by
+		 * the relevant capability.
+		 */
+		if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
+			if (!capable(CAP_SYS_RESOURCE)) {
+				mutex_unlock(&inode->i_mutex);
+				return -EPERM;
+			}
+		}
+
+
+		handle = ext3_journal_start(inode, 1);
+		if (IS_ERR(handle)) {
+			mutex_unlock(&inode->i_mutex);
+			return PTR_ERR(handle);
+		}
+		if (IS_SYNC(inode))
+			handle->h_sync = 1;
+		err = ext3_reserve_inode_write(handle, inode, &iloc);
+		if (err)
+			goto flags_err;
+
+		flags = flags & EXT3_FL_USER_MODIFIABLE;
+		flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
+		ei->i_flags = flags;
+
+		ext3_set_inode_flags(inode);
+		inode->i_ctime = CURRENT_TIME_SEC;
+
+		err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+flags_err:
+		ext3_journal_stop(handle);
+		if (err) {
+			mutex_unlock(&inode->i_mutex);
+			return err;
+		}
+
+		if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
+			err = ext3_change_inode_journal_flag(inode, jflag);
+		mutex_unlock(&inode->i_mutex);
+		return err;
+	}
+	case EXT3_IOC_GETVERSION:
+	case EXT3_IOC_GETVERSION_OLD:
+		return put_user(inode->i_generation, (int __user *) arg);
+	case EXT3_IOC_SETVERSION:
+	case EXT3_IOC_SETVERSION_OLD: {
+		handle_t *handle;
+		struct ext3_iloc iloc;
+		__u32 generation;
+		int err;
+
+		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+			return -EPERM;
+		if (IS_RDONLY(inode))
+			return -EROFS;
+		if (get_user(generation, (int __user *) arg))
+			return -EFAULT;
+
+		handle = ext3_journal_start(inode, 1);
+		if (IS_ERR(handle))
+			return PTR_ERR(handle);
+		err = ext3_reserve_inode_write(handle, inode, &iloc);
+		if (err == 0) {
+			inode->i_ctime = CURRENT_TIME_SEC;
+			inode->i_generation = generation;
+			err = ext3_mark_iloc_dirty(handle, inode, &iloc);
+		}
+		ext3_journal_stop(handle);
+		return err;
+	}
+#ifdef CONFIG_JBD_DEBUG
+	case EXT3_IOC_WAIT_FOR_READONLY:
+		/*
+		 * This is racy - by the time we're woken up and running,
+		 * the superblock could be released.  And the module could
+		 * have been unloaded.  So sue me.
+		 *
+		 * Returns 1 if it slept, else zero.
+		 */
+		{
+			struct super_block *sb = inode->i_sb;
+			DECLARE_WAITQUEUE(wait, current);
+			int ret = 0;
+
+			set_current_state(TASK_INTERRUPTIBLE);
+			add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
+			if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
+				schedule();
+				ret = 1;
+			}
+			remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
+			return ret;
+		}
+#endif
+	case EXT3_IOC_GETRSVSZ:
+		if (test_opt(inode->i_sb, RESERVATION)
+			&& S_ISREG(inode->i_mode)
+			&& ei->i_block_alloc_info) {
+			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+			return put_user(rsv_window_size, (int __user *)arg);
+		}
+		return -ENOTTY;
+	case EXT3_IOC_SETRSVSZ: {
+
+		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+			return -ENOTTY;
+
+		if (IS_RDONLY(inode))
+			return -EROFS;
+
+		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
+			return -EACCES;
+
+		if (get_user(rsv_window_size, (int __user *)arg))
+			return -EFAULT;
+
+		if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
+			rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
+
+		/*
+		 * need to allocate reservation structure for this inode
+		 * before set the window size
+		 */
+		mutex_lock(&ei->truncate_mutex);
+		if (!ei->i_block_alloc_info)
+			ext3_init_block_alloc_info(inode);
+
+		if (ei->i_block_alloc_info){
+			struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+			rsv->rsv_goal_size = rsv_window_size;
+		}
+		mutex_unlock(&ei->truncate_mutex);
+		return 0;
+	}
+	case EXT3_IOC_GROUP_EXTEND: {
+		ext3_fsblk_t n_blocks_count;
+		struct super_block *sb = inode->i_sb;
+		int err;
+
+		if (!capable(CAP_SYS_RESOURCE))
+			return -EPERM;
+
+		if (IS_RDONLY(inode))
+			return -EROFS;
+
+		if (get_user(n_blocks_count, (__u32 __user *)arg))
+			return -EFAULT;
+
+		err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
+		journal_lock_updates(EXT3_SB(sb)->s_journal);
+		journal_flush(EXT3_SB(sb)->s_journal);
+		journal_unlock_updates(EXT3_SB(sb)->s_journal);
+
+		return err;
+	}
+	case EXT3_IOC_GROUP_ADD: {
+		struct ext3_new_group_data input;
+		struct super_block *sb = inode->i_sb;
+		int err;
+
+		if (!capable(CAP_SYS_RESOURCE))
+			return -EPERM;
+
+		if (IS_RDONLY(inode))
+			return -EROFS;
+
+		if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
+				sizeof(input)))
+			return -EFAULT;
+
+		err = ext3_group_add(sb, &input);
+		journal_lock_updates(EXT3_SB(sb)->s_journal);
+		journal_flush(EXT3_SB(sb)->s_journal);
+		journal_unlock_updates(EXT3_SB(sb)->s_journal);
+
+		return err;
+	}
+
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long ext3_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	int ret;
+
+	/* These are just misnamed, they actually get/put from/to user an int */
+	switch (cmd) {
+	case EXT3_IOC32_GETFLAGS:
+		cmd = EXT3_IOC_GETFLAGS;
+		break;
+	case EXT3_IOC32_SETFLAGS:
+		cmd = EXT3_IOC_SETFLAGS;
+		break;
+	case EXT3_IOC32_GETVERSION:
+		cmd = EXT3_IOC_GETVERSION;
+		break;
+	case EXT3_IOC32_SETVERSION:
+		cmd = EXT3_IOC_SETVERSION;
+		break;
+	case EXT3_IOC32_GROUP_EXTEND:
+		cmd = EXT3_IOC_GROUP_EXTEND;
+		break;
+	case EXT3_IOC32_GETVERSION_OLD:
+		cmd = EXT3_IOC_GETVERSION_OLD;
+		break;
+	case EXT3_IOC32_SETVERSION_OLD:
+		cmd = EXT3_IOC_SETVERSION_OLD;
+		break;
+#ifdef CONFIG_JBD_DEBUG
+	case EXT3_IOC32_WAIT_FOR_READONLY:
+		cmd = EXT3_IOC_WAIT_FOR_READONLY;
+		break;
+#endif
+	case EXT3_IOC32_GETRSVSZ:
+		cmd = EXT3_IOC_GETRSVSZ;
+		break;
+	case EXT3_IOC32_SETRSVSZ:
+		cmd = EXT3_IOC_SETRSVSZ;
+		break;
+	case EXT3_IOC_GROUP_ADD:
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	lock_kernel();
+	ret = ext3_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
+	unlock_kernel();
+	return ret;
+}
+#endif

fs/ext4/namei.h

+/*  linux/fs/ext3/namei.h
+ *
+ * Copyright (C) 2005 Simtec Electronics
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+*/
+
+extern struct dentry *ext3_get_parent(struct dentry *child);

fs/ext4/symlink.c

+/*
+ *  linux/fs/ext3/symlink.c
+ *
+ * Only fast symlinks left here - the rest is done by generic code. AV, 1999
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/symlink.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext3 symlink handling code
+ */
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/namei.h>
+#include "xattr.h"
+
+static void * ext3_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct ext3_inode_info *ei = EXT3_I(dentry->d_inode);
+	nd_set_link(nd, (char*)ei->i_data);
+	return NULL;
+}
+
+struct inode_operations ext3_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= page_follow_link_light,
+	.put_link	= page_put_link,
+#ifdef CONFIG_EXT3_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext3_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+};
+
+struct inode_operations ext3_fast_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= ext3_follow_link,
+#ifdef CONFIG_EXT3_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= ext3_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+};

fs/ext4/xattr.h

+/*
+  File: fs/ext3/xattr.h
+
+  On-disk format of extended attributes for the ext3 filesystem.
+
+  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define EXT3_XATTR_MAGIC		0xEA020000
+
+/* Maximum number of references to one attribute block */
+#define EXT3_XATTR_REFCOUNT_MAX		1024
+
+/* Name indexes */
+#define EXT3_XATTR_INDEX_USER			1
+#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS	2
+#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT	3
+#define EXT3_XATTR_INDEX_TRUSTED		4
+#define	EXT3_XATTR_INDEX_LUSTRE			5
+#define EXT3_XATTR_INDEX_SECURITY	        6
+
+struct ext3_xattr_header {
+	__le32	h_magic;	/* magic number for identification */
+	__le32	h_refcount;	/* reference count */
+	__le32	h_blocks;	/* number of disk blocks used */
+	__le32	h_hash;		/* hash value of all attributes */
+	__u32	h_reserved[4];	/* zero right now */
+};
+
+struct ext3_xattr_ibody_header {
+	__le32	h_magic;	/* magic number for identification */
+};
+
+struct ext3_xattr_entry {
+	__u8	e_name_len;	/* length of name */
+	__u8	e_name_index;	/* attribute name index */
+	__le16	e_value_offs;	/* offset in disk block of value */
+	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
+	__le32	e_value_size;	/* size of attribute value */
+	__le32	e_hash;		/* hash value of name and value */
+	char	e_name[0];	/* attribute name */
+};
+
+#define EXT3_XATTR_PAD_BITS		2
+#define EXT3_XATTR_PAD		(1<<EXT3_XATTR_PAD_BITS)
+#define EXT3_XATTR_ROUND		(EXT3_XATTR_PAD-1)
+#define EXT3_XATTR_LEN(name_len) \
+	(((name_len) + EXT3_XATTR_ROUND + \
+	sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
+#define EXT3_XATTR_NEXT(entry) \
+	( (struct ext3_xattr_entry *)( \
+	  (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
+#define EXT3_XATTR_SIZE(size) \
+	(((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
+
+# ifdef CONFIG_EXT3_FS_XATTR
+
+extern struct xattr_handler ext3_xattr_user_handler;
+extern struct xattr_handler ext3_xattr_trusted_handler;
+extern struct xattr_handler ext3_xattr_acl_access_handler;
+extern struct xattr_handler ext3_xattr_acl_default_handler;
+extern struct xattr_handler ext3_xattr_security_handler;
+
+extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
+
+extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
+extern int ext3_xattr_list(struct inode *, char *, size_t);
+extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
+extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
+
+extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
+extern void ext3_xattr_put_super(struct super_block *);
+
+extern int init_ext3_xattr(void);
+extern void exit_ext3_xattr(void);
+
+extern struct xattr_handler *ext3_xattr_handlers[];
+
+# else  /* CONFIG_EXT3_FS_XATTR */
+
+static inline int
+ext3_xattr_get(struct inode *inode, int name_index, const char *name,
+	       void *buffer, size_t size, int flags)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_list(struct inode *inode, void *buffer, size_t size)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_set(struct inode *inode, int name_index, const char *name,
+	       const void *value, size_t size, int flags)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int
+ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
+	       const char *name, const void *value, size_t size, int flags)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void
+ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
+{
+}
+
+static inline void
+ext3_xattr_put_super(struct super_block *sb)
+{
+}
+
+static inline int
+init_ext3_xattr(void)
+{
+	return 0;
+}
+
+static inline void
+exit_ext3_xattr(void)
+{
+}
+
+#define ext3_xattr_handlers	NULL
+
+# endif  /* CONFIG_EXT3_FS_XATTR */
+
+#ifdef CONFIG_EXT3_FS_SECURITY
+extern int ext3_init_security(handle_t *handle, struct inode *inode,
+				struct inode *dir);
+#else
+static inline int ext3_init_security(handle_t *handle, struct inode *inode,
+				struct inode *dir)
+{
+	return 0;
+}
+#endif

fs/ext4/xattr_security.c

+/*
+ * linux/fs/ext3/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include <linux/security.h>
+#include "xattr.h"
+
+static size_t
+ext3_xattr_security_list(struct inode *inode, char *list, size_t list_size,
+			 const char *name, size_t name_len)
+{
+	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
+	const size_t total_len = prefix_len + name_len + 1;
+
+
+	if (list && total_len <= list_size) {
+		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
+		memcpy(list+prefix_len, name, name_len);
+		list[prefix_len + name_len] = '\0';
+	}
+	return total_len;
+}
+
+static int
+ext3_xattr_security_get(struct inode *inode, const char *name,
+		       void *buffer, size_t size)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_get(inode, EXT3_XATTR_INDEX_SECURITY, name,
+			      buffer, size);
+}
+
+static int
+ext3_xattr_security_set(struct inode *inode, const char *name,
+		       const void *value, size_t size, int flags)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_set(inode, EXT3_XATTR_INDEX_SECURITY, name,
+			      value, size, flags);
+}
+
+int
+ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+	int err;
+	size_t len;
+	void *value;
+	char *name;
+
+	err = security_inode_init_security(inode, dir, &name, &value, &len);
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			return 0;
+		return err;
+	}
+	err = ext3_xattr_set_handle(handle, inode, EXT3_XATTR_INDEX_SECURITY,
+				    name, value, len, 0);
+	kfree(name);
+	kfree(value);
+	return err;
+}
+
+struct xattr_handler ext3_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.list	= ext3_xattr_security_list,
+	.get	= ext3_xattr_security_get,
+	.set	= ext3_xattr_security_set,
+};

fs/ext4/xattr_trusted.c

+/*
+ * linux/fs/ext3/xattr_trusted.c
+ * Handler for trusted extended attributes.
+ *
+ * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/capability.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+#define XATTR_TRUSTED_PREFIX "trusted."
+
+static size_t
+ext3_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
+			const char *name, size_t name_len)
+{
+	const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
+	const size_t total_len = prefix_len + name_len + 1;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return 0;
+
+	if (list && total_len <= list_size) {
+		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
+		memcpy(list+prefix_len, name, name_len);
+		list[prefix_len + name_len] = '\0';
+	}
+	return total_len;
+}
+
+static int
+ext3_xattr_trusted_get(struct inode *inode, const char *name,
+		       void *buffer, size_t size)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_get(inode, EXT3_XATTR_INDEX_TRUSTED, name,
+			      buffer, size);
+}
+
+static int
+ext3_xattr_trusted_set(struct inode *inode, const char *name,
+		       const void *value, size_t size, int flags)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return ext3_xattr_set(inode, EXT3_XATTR_INDEX_TRUSTED, name,
+			      value, size, flags);
+}
+
+struct xattr_handler ext3_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.list	= ext3_xattr_trusted_list,
+	.get	= ext3_xattr_trusted_get,
+	.set	= ext3_xattr_trusted_set,
+};

fs/ext4/xattr_user.c

+/*
+ * linux/fs/ext3/xattr_user.c
+ * Handler for extended user attributes.
+ *
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext3_jbd.h>
+#include <linux/ext3_fs.h>
+#include "xattr.h"
+
+#define XATTR_USER_PREFIX "user."
+
+static size_t
+ext3_xattr_user_list(struct inode *inode, char *list, size_t list_size,
+		     const char *name, size_t name_len)
+{
+	const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
+	const size_t total_len = prefix_len + name_len + 1;
+
+	if (!test_opt(inode->i_sb, XATTR_USER))
+		return 0;
+
+	if (list && total_len <= list_size) {
+		memcpy(list, XATTR_USER_PREFIX, prefix_len);
+		memcpy(list+prefix_len, name, name_len);
+		list[prefix_len + name_len] = '\0';
+	}
+	return total_len;
+}
+
+static int
+ext3_xattr_user_get(struct inode *inode, const char *name,
+		    void *buffer, size_t size)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	if (!test_opt(inode->i_sb, XATTR_USER))
+		return -EOPNOTSUPP;
+	return ext3_xattr_get(inode, EXT3_XATTR_INDEX_USER, name, buffer, size);
+}
+
+static int
+ext3_xattr_user_set(struct inode *inode, const char *name,
+		    const void *value, size_t size, int flags)
+{
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	if (!test_opt(inode->i_sb, XATTR_USER))
+		return -EOPNOTSUPP;
+	return ext3_xattr_set(inode, EXT3_XATTR_INDEX_USER, name,
+			      value, size, flags);
+}
+
+struct xattr_handler ext3_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.list	= ext3_xattr_user_list,
+	.get	= ext3_xattr_user_get,
+	.set	= ext3_xattr_user_set,
+};

include/linux/ext4_fs_sb.h

+/*
+ *  linux/include/linux/ext3_fs_sb.h
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/include/linux/minix_fs_sb.h
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#ifndef _LINUX_EXT3_FS_SB
+#define _LINUX_EXT3_FS_SB
+
+#ifdef __KERNEL__
+#include <linux/timer.h>
+#include <linux/wait.h>
+#include <linux/blockgroup_lock.h>
+#include <linux/percpu_counter.h>
+#endif
+#include <linux/rbtree.h>
+
+/*
+ * third extended-fs super-block data in memory
+ */
+struct ext3_sb_info {
+	unsigned long s_frag_size;	/* Size of a fragment in bytes */
+	unsigned long s_frags_per_block;/* Number of fragments per block */
+	unsigned long s_inodes_per_block;/* Number of inodes per block */
+	unsigned long s_frags_per_group;/* Number of fragments in a group */
+	unsigned long s_blocks_per_group;/* Number of blocks in a group */
+	unsigned long s_inodes_per_group;/* Number of inodes in a group */
+	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
+	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
+	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
+	unsigned long s_groups_count;	/* Number of groups in the fs */
+	struct buffer_head * s_sbh;	/* Buffer containing the super block */
+	struct ext3_super_block * s_es;	/* Pointer to the super block in the buffer */
+	struct buffer_head ** s_group_desc;
+	unsigned long  s_mount_opt;
+	uid_t s_resuid;
+	gid_t s_resgid;
+	unsigned short s_mount_state;
+	unsigned short s_pad;
+	int s_addr_per_block_bits;
+	int s_desc_per_block_bits;
+	int s_inode_size;
+	int s_first_ino;
+	spinlock_t s_next_gen_lock;
+	u32 s_next_generation;
+	u32 s_hash_seed[4];
+	int s_def_hash_version;
+	struct percpu_counter s_freeblocks_counter;
+	struct percpu_counter s_freeinodes_counter;
+	struct percpu_counter s_dirs_counter;
+	struct blockgroup_lock s_blockgroup_lock;
+
+	/* root of the per fs reservation window tree */
+	spinlock_t s_rsv_window_lock;
+	struct rb_root s_rsv_window_root;
+	struct ext3_reserve_window_node s_rsv_window_head;
+
+	/* Journaling */
+	struct inode * s_journal_inode;
+	struct journal_s * s_journal;
+	struct list_head s_orphan;
+	unsigned long s_commit_interval;
+	struct block_device *journal_bdev;
+#ifdef CONFIG_JBD_DEBUG
+	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
+	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
+#endif
+#ifdef CONFIG_QUOTA
+	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
+	int s_jquota_fmt;			/* Format of quota to use */
+#endif
+};
+
+#endif	/* _LINUX_EXT3_FS_SB */