+/*
+ * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
+ * Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
+ *
+ *
+ * HelenOS:
+ * Copyright (c) 2012 Martin Sucha
+ * Copyright (c) 2012 Frantisek Princ
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup lwext4
+ * @{
+ */
+/**
+ * @file ext4_xattr.c
+ * @brief Extended Attribute manipulation.
+ */
+
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_fs.h"
#include <string.h>
#include <stdlib.h>
-static int ext4_xattr_item_cmp(struct ext4_rb_node *a_,
- struct ext4_rb_node *b_)
-{
- struct ext4_xattr_item *a, *b;
- int result;
- a = container_of(a_, struct ext4_xattr_item, node);
- b = container_of(b_, struct ext4_xattr_item, node);
- result = a->name_index - b->name_index;
- if (result)
- return result;
-
- result = a->name_len - b->name_len;
- if (result)
- return result;
+/**
+ * @file ext4_xattr.c
+ * @brief Extended Attribute Manipulation
+ */
- return memcmp(a->name, b->name, a->name_len);
-}
+#define NAME_HASH_SHIFT 5
+#define VALUE_HASH_SHIFT 16
-static struct ext4_xattr_item *
-ext4_xattr_item_lookup(struct ext4_rb_root *root,
- uint8_t name_index,
- char *name,
- size_t name_len)
+static inline void
+ext4_xattr_compute_hash(struct ext4_xattr_header *header,
+ struct ext4_xattr_entry *entry)
{
- struct ext4_rb_node *new = root->ext4_rb_node;
-
- /* Figure out where to put new node */
- while (new) {
- struct ext4_xattr_item *item =
- container_of(new, struct ext4_xattr_item, node);
- int result = name_index - item->name_index;
- if (!result) {
- result = name_len - item->name_len;
- if (!result)
- result = memcmp(name,
- item->name, name_len);
+ uint32_t hash = 0;
+ char *name = EXT4_XATTR_NAME(entry);
+ int n;
+
+ for (n = 0; n < entry->e_name_len; n++) {
+ hash = (hash << NAME_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
+ *name++;
+ }
+ if (entry->e_value_block == 0 && entry->e_value_size != 0) {
+ uint32_t *value = (uint32_t *)((char *)header +
+ to_le16(entry->e_value_offs));
+ for (n = (to_le32(entry->e_value_size) +
+ EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
+ hash = (hash << VALUE_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
+ to_le32(*value++);
}
-
- if (result < 0)
- new = new->ext4_rb_left;
- else if (result > 0)
- new = new->ext4_rb_right;
- else
- return item;
-
}
-
- return NULL;
+ entry->e_hash = to_le32(hash);
}
-static void
-ext4_xattr_item_insert(struct ext4_rb_root *root,
- struct ext4_xattr_item *item)
+#define BLOCK_HASH_SHIFT 16
+
+/*
+ * ext4_xattr_rehash()
+ *
+ * Re-compute the extended attribute hash value after an entry has changed.
+ */
+static void ext4_xattr_rehash(struct ext4_xattr_header *header,
+ struct ext4_xattr_entry *entry)
{
- ext4_rb_insert(root, &item->node, ext4_xattr_item_cmp);
+ struct ext4_xattr_entry *here;
+ uint32_t hash = 0;
+
+ ext4_xattr_compute_hash(header, entry);
+ here = EXT4_XATTR_ENTRY(header+1);
+ while (!EXT4_XATTR_IS_LAST_ENTRY(here)) {
+ if (!here->e_hash) {
+ /* Block is not shared if an entry's hash value == 0 */
+ hash = 0;
+ break;
+ }
+ hash = (hash << BLOCK_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
+ to_le32(here->e_hash);
+ here = EXT4_XATTR_NEXT(here);
+ }
+ header->h_hash = to_le32(hash);
}
-static void
-ext4_xattr_item_remove(struct ext4_rb_root *root,
- struct ext4_xattr_item *item)
+static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
+ struct ext4_xattr_item *b)
{
- ext4_rb_erase(&item->node, root);
+ int result;
+ result = a->name_index - b->name_index;
+ if (result)
+ return result;
+
+ result = a->name_len - b->name_len;
+ if (result)
+ return result;
+
+ return memcmp(a->name, b->name, a->name_len);
}
+RB_GENERATE_INTERNAL(ext4_xattr_tree,
+ ext4_xattr_item,
+ node,
+ ext4_xattr_item_cmp,
+ static inline)
static struct ext4_xattr_item *
ext4_xattr_item_alloc(uint8_t name_index,
entry = EXT4_XATTR_NEXT(entry),
size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
struct ext4_xattr_item *item;
- char *e_name = (char *)(entry + 1);
+ char *e_name = EXT4_XATTR_NAME(entry);
data = ext4_xattr_entry_data(xattr_ref, entry,
false);
}
if (ext4_xattr_item_alloc_data(item,
data,
- to_le32(entry->e_value_size)
- != EOK)) {
+ to_le32(entry->e_value_size))
+ != EOK) {
ext4_xattr_item_free(item);
ret = ENOMEM;
goto Finish;
}
- ext4_xattr_item_insert(&xattr_ref->root,
- item);
-
+ RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
+ xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
}
Finish:
entry = EXT4_XATTR_NEXT(entry),
size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
struct ext4_xattr_item *item;
- char *e_name = (char *)(entry + 1);
+ char *e_name = EXT4_XATTR_NAME(entry);
data = ext4_xattr_entry_data(xattr_ref, entry,
true);
}
if (ext4_xattr_item_alloc_data(item,
data,
- to_le32(entry->e_value_size)
- != EOK)) {
+ to_le32(entry->e_value_size))
+ != EOK) {
ext4_xattr_item_free(item);
ret = ENOMEM;
goto Finish;
}
- ext4_xattr_item_insert(&xattr_ref->root,
- item);
-
-
+ RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
+ xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
}
Finish:
return ret;
}
+
+static size_t
+ext4_xattr_inode_space(struct ext4_xattr_ref *xattr_ref)
+{
+ uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
+ inode_size);
+ uint16_t size_rem = inode_size -
+ EXT4_GOOD_OLD_INODE_SIZE -
+ xattr_ref->inode_ref->inode->extra_isize;
+ return size_rem;
+}
+
+static size_t
+ext4_xattr_block_space(struct ext4_xattr_ref *xattr_ref)
+{
+ return ext4_sb_get_block_size(&xattr_ref->fs->sb);
+}
+
static int ext4_xattr_fetch(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
return ret;
}
+static struct ext4_xattr_item *
+ext4_xattr_lookup_item(struct ext4_xattr_ref *xattr_ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len)
+{
+ struct ext4_xattr_item tmp, *ret;
+ tmp.name_index = name_index;
+ tmp.name = name;
+ tmp.name_len = name_len;
+ ret = RB_FIND(ext4_xattr_tree, &xattr_ref->root,
+ &tmp);
+ return ret;
+}
+
+static struct ext4_xattr_item *
+ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len,
+ void *data,
+ size_t data_size)
+{
+ struct ext4_xattr_item *item;
+ item = ext4_xattr_item_alloc(name_index,
+ name,
+ name_len);
+ if (!item)
+ return NULL;
+
+ if (xattr_ref->ea_size + EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len) >
+ ext4_xattr_inode_space(xattr_ref) +
+ ext4_xattr_block_space(xattr_ref)) {
+ ext4_xattr_item_free(item);
+ return NULL;
+ }
+ if (ext4_xattr_item_alloc_data(item,
+ data,
+ data_size) != EOK) {
+ ext4_xattr_item_free(item);
+ return NULL;
+ }
+ RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
+ xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
+ xattr_ref->dirty = true;
+ return item;
+}
+
+static int
+ext4_xattr_remove_item(struct ext4_xattr_ref *xattr_ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len)
+{
+ int ret = ENOENT;
+ struct ext4_xattr_item *item =
+ ext4_xattr_lookup_item(xattr_ref,
+ name_index,
+ name,
+ name_len);
+ if (item) {
+ RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
+ ext4_xattr_item_free(item);
+ xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
+ xattr_ref->dirty = true;
+ ret = EOK;
+ }
+ return ret;
+}
+
+static int
+ext4_xattr_resize_item(struct ext4_xattr_ref *xattr_ref,
+ struct ext4_xattr_item *item,
+ size_t new_data_size)
+{
+ int ret = EOK;
+ if (xattr_ref->ea_size - EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_SIZE(new_data_size) >
+ ext4_xattr_inode_space(xattr_ref) +
+ ext4_xattr_block_space(xattr_ref)) {
+
+ return ENOSPC;
+ }
+ ret = ext4_xattr_item_resize_data(item,
+ new_data_size);
+ if (ret != EOK) {
+ return ret;
+ }
+ xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_SIZE(new_data_size);
+ xattr_ref->dirty = true;
+ return ret;
+}
+
static void
ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
{
- struct ext4_rb_node *node;
- while ((node = ext4_rb_first(&xattr_ref->root))) {
- struct ext4_xattr_item *item = ext4_rb_entry(
- node, struct ext4_xattr_item, node);
- ext4_xattr_item_remove(&xattr_ref->root, item);
+ struct ext4_xattr_item *item, *save_item;
+ RB_FOREACH_SAFE(item,
+ ext4_xattr_tree,
+ &xattr_ref->root,
+ save_item) {
+ RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
ext4_xattr_item_free(item);
}
+ xattr_ref->ea_size = sizeof(struct ext4_xattr_header) +
+ sizeof(struct ext4_xattr_ibody_header);
+}
+
+
+static int
+ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
+{
+ int ret = EOK;
+
+ uint64_t xattr_block;
+ xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
+ &xattr_ref->fs->sb);
+ if (!xattr_block) {
+ ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
+ (uint32_t *)&xattr_block);
+ if (ret != EOK)
+ goto Finish;
+
+ ret = ext4_block_get(xattr_ref->fs->bdev,
+ &xattr_ref->block,
+ xattr_block);
+ if (ret != EOK) {
+ ext4_balloc_free_block(xattr_ref->inode_ref,
+ xattr_block);
+ goto Finish;
+ }
+
+ ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
+ &xattr_ref->fs->sb,
+ xattr_block);
+ xattr_ref->inode_ref->dirty = true;
+ xattr_ref->block_loaded = true;
+ xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
+}
+
+Finish:
+ return ret;
+}
+
+static void
+ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
+{
+ uint64_t xattr_block;
+ xattr_block =
+ ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
+ &xattr_ref->fs->sb);
+ ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
+ &xattr_ref->fs->sb,
+ 0);
+ ext4_block_set(xattr_ref->fs->bdev,
+ &xattr_ref->block);
+ ext4_balloc_free_block(xattr_ref->inode_ref,
+ xattr_block);
+ xattr_ref->inode_ref->dirty = true;
+ xattr_ref->block_loaded = false;
+ xattr_ref->ea_size -= sizeof(struct ext4_xattr_header);
+
+}
+
+static int
+ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
+{
+ int ret = EOK;
+ bool block_modified = false;
+ void *ibody_data, *block_data;
+ struct ext4_xattr_item *item, *save_item;
+ size_t inode_size_rem, block_size_rem;
+ struct ext4_xattr_header *header = NULL;
+ struct ext4_xattr_ibody_header *ibody_header = NULL;
+ struct ext4_xattr_entry *entry = NULL;
+ struct ext4_xattr_entry *block_entry = NULL;
+
+ inode_size_rem = ext4_xattr_inode_space(xattr_ref);
+ block_size_rem = ext4_xattr_block_space(xattr_ref);
+ if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
+ ibody_header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
+ entry = EXT4_XATTR_IFIRST(ibody_header);
+ }
+
+ if (xattr_ref->dirty) {
+ /* If there are enough spaces in the ibody EA table.*/
+ if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
+ memset(ibody_header, 0, inode_size_rem);
+ ibody_header->h_magic = EXT4_XATTR_MAGIC;
+ xattr_ref->inode_ref->dirty = true;
+ ibody_data = (char *)ibody_header + inode_size_rem;
+ inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
+ }
+ /* If we need an extra block to hold the EA entries*/
+ if (xattr_ref->ea_size > inode_size_rem) {
+ if (!xattr_ref->block_loaded) {
+ ret = ext4_xattr_try_alloc_block(xattr_ref);
+ if (ret != EOK)
+ goto Finish;
+
+ }
+ header = EXT4_XATTR_BHDR(&xattr_ref->block);
+ block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
+ memset(header, 0, sizeof(struct ext4_xattr_header));
+ header->h_magic = EXT4_XATTR_MAGIC;
+ header->h_refcount = to_le32(1);
+ header->h_blocks = to_le32(1);
+ block_data = (char *)header + block_size_rem;
+ block_size_rem -= sizeof(struct ext4_xattr_header);
+ xattr_ref->block.dirty = true;
+ } else {
+ /* We don't need an extra block.*/
+ if (xattr_ref->block_loaded) {
+ header = EXT4_XATTR_BHDR(&xattr_ref->block);
+ header->h_refcount =
+ to_le32(to_le32(header->h_refcount) - 1);
+ if (!header->h_refcount) {
+ ext4_xattr_try_free_block(xattr_ref);
+ header = NULL;
+ } else {
+ xattr_ref->block.dirty = true;
+ block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
+ block_data = (char *)header + block_size_rem;
+ block_size_rem -= sizeof(struct ext4_xattr_header);
+ }
+ }
+ }
+ RB_FOREACH_SAFE(item,
+ ext4_xattr_tree,
+ &xattr_ref->root,
+ save_item) {
+ if (EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len) <=
+ inode_size_rem) {
+ ibody_data = (char *)ibody_data - EXT4_XATTR_SIZE(item->data_size);
+ entry->e_name_len = to_le32(item->name_len);
+ entry->e_name_index = item->name_index;
+ entry->e_value_offs =
+ (char *)ibody_data -
+ (char *)EXT4_XATTR_IFIRST(ibody_header);
+ entry->e_value_block = 0;
+ entry->e_value_size = item->data_size;
+ memcpy(EXT4_XATTR_NAME(entry), item->name, item->name_len);
+ memcpy(ibody_data, item->data, item->data_size);
+ entry = EXT4_XATTR_NEXT(entry);
+ inode_size_rem -=
+ EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
+ continue;
+ }
+ if (EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len) > block_size_rem) {
+ ret = ENOSPC;
+ goto Finish;
+ }
+ block_data = (char *)block_data - EXT4_XATTR_SIZE(item->data_size);
+ block_entry->e_name_len = to_le32(item->name_len);
+ block_entry->e_name_index = item->name_index;
+ block_entry->e_value_offs =
+ (char *)block_data - (char *)header;
+ block_entry->e_value_block = 0;
+ block_entry->e_value_size = item->data_size;
+ memcpy(EXT4_XATTR_NAME(block_entry), item->name, item->name_len);
+ memcpy(block_data, item->data, item->data_size);
+ block_entry = EXT4_XATTR_NEXT(block_entry);
+ block_size_rem -=
+ EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
+ block_modified = true;
+ }
+ xattr_ref->dirty = false;
+ if (block_modified) {
+ ext4_xattr_rehash(header,
+ EXT4_XATTR_BFIRST(&xattr_ref->block));
+ }
+ }
+
+Finish:
+ return ret;
+}
+
+
+int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len,
+ void *data,
+ size_t data_size,
+ bool replace)
+{
+ int ret = EOK;
+ struct ext4_xattr_item *item =
+ ext4_xattr_lookup_item(ref,
+ name_index,
+ name,
+ name_len);
+ if (replace) {
+ if (!item) {
+ ret = ENOATTR;
+ goto Finish;
+ }
+ if (item->data_size != data_size)
+ ret = ext4_xattr_resize_item(ref,
+ item,
+ data_size);
+
+ if (ret != EOK) {
+ goto Finish;
+ }
+ memcpy(item->data, data, data_size);
+ } else {
+ if (item) {
+ ret = EEXIST;
+ goto Finish;
+ }
+ item = ext4_xattr_insert_item(ref,
+ name_index,
+ name,
+ name_len,
+ data,
+ data_size);
+ if (!item)
+ ret = ENOMEM;
+
+ }
+Finish:
+ return ret;
+}
+
+int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len)
+{
+ return ext4_xattr_remove_item(ref,
+ name_index,
+ name,
+ name_len);
+}
+
+int ext4_fs_get_xattr(struct ext4_xattr_ref *ref,
+ uint8_t name_index,
+ char *name,
+ size_t name_len,
+ void *buf,
+ size_t buf_size,
+ size_t *size_got)
+{
+ int ret = EOK;
+ size_t item_size = 0;
+ struct ext4_xattr_item *item =
+ ext4_xattr_lookup_item(ref,
+ name_index,
+ name,
+ name_len);
+
+ if (!item) {
+ ret = ENOATTR;
+ goto Finish;
+ }
+ item_size = item->data_size;
+ if (buf_size > item_size)
+ buf_size = item_size;
+
+ if (buf)
+ memcpy(buf, item->data, buf_size);
+
+Finish:
+ if (size_got)
+ *size_got = buf_size;
+
+ return ret;
}
int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
uint64_t xattr_block;
xattr_block = ext4_inode_get_file_acl(inode_ref->inode,
&fs->sb);
- memset(&ref->root, 0, sizeof(ref->root));
+ RB_INIT(&ref->root);
+ ref->ea_size = 0;
if (xattr_block) {
rc = ext4_block_get(fs->bdev,
&inode_ref->block, xattr_block);
if (rc != EOK)
return EIO;
+ ref->ea_size += sizeof(struct ext4_xattr_header);
ref->block_loaded = true;
} else
ref->block_loaded = false;
ref->inode_ref = inode_ref;
ref->fs = fs;
+ if (ext4_xattr_inode_space(ref) >
+ sizeof(struct ext4_xattr_ibody_header))
+ ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
+
rc = ext4_xattr_fetch(ref);
if (rc != EOK) {
ext4_xattr_purge_items(ref);
ext4_block_set(ref->fs->bdev, &ref->block);
ref->block_loaded = false;
}
+ ext4_xattr_write_to_disk(ref);
ext4_xattr_purge_items(ref);
ref->inode_ref = NULL;
ref->fs = NULL;
}
+/**
+ * @}
+ */