]> git.ipfire.org Git - thirdparty/e2fsprogs.git/commitdiff
libext2fs: support modifying arbitrary extended attributes
authorDarrick J. Wong <darrick.wong@oracle.com>
Sun, 23 Feb 2014 01:40:38 +0000 (20:40 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Mon, 24 Feb 2014 04:08:23 +0000 (23:08 -0500)
Add functions to allow clients to get, set, and remove extended
attributes from any file.  It also supports modifying EAs living in
i_file_acl.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
lib/ext2fs/ext2_err.et.in
lib/ext2fs/ext2fs.h
lib/ext2fs/ext_attr.c

index 93a11064683e0e5fb37ffdef6f502d37ae4db7ca..0a69aa311ed26eb1fca384477b5b1533ceb4657b 100644 (file)
@@ -482,4 +482,25 @@ ec EXT2_ET_BLOCK_BITMAP_CSUM_INVALID,
 ec     EXT2_ET_INLINE_DATA_CANT_ITERATE,
        "Cannot iterate data blocks of an inode containing inline data"
 
+ec     EXT2_ET_EA_BAD_NAME_LEN,
+       "Extended attribute has an invalid name length"
+
+ec     EXT2_ET_EA_BAD_VALUE_SIZE,
+       "Extended attribute has an invalid value length"
+
+ec     EXT2_ET_BAD_EA_HASH,
+       "Extended attribute has an incorrect hash"
+
+ec     EXT2_ET_BAD_EA_HEADER,
+       "Extended attribute block has a bad header"
+
+ec     EXT2_ET_EA_KEY_NOT_FOUND,
+       "Extended attribute key not found"
+
+ec     EXT2_ET_EA_NO_SPACE,
+       "Insufficient space to store extended attribute data"
+
+ec     EXT2_ET_MISSING_EA_FEATURE,
+       "Filesystem is missing ext_attr or inline_data feature"
+
        end
index 7f7fd1f9dc5edde7fca2661a133e182e389ee91f..9392ff49d4b655df2dd1f943742c9e262b7dc78f 100644 (file)
@@ -637,6 +637,13 @@ typedef struct stat ext2fs_struct_stat;
  */
 #define EXT2_FLAG_FLUSH_NO_SYNC          1
 
+/*
+ * Modify and iterate extended attributes
+ */
+struct ext2_xattr_handle;
+#define XATTR_ABORT    1
+#define XATTR_CHANGED  2
+
 /*
  * function prototypes
  */
@@ -1154,6 +1161,27 @@ extern errcode_t ext2fs_adjust_ea_refcount3(ext2_filsys fs, blk64_t blk,
                                           char *block_buf,
                                           int adjust, __u32 *newcount,
                                           ext2_ino_t inum);
+errcode_t ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
+                              unsigned int expandby);
+errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle);
+errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle);
+errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
+                               int (*func)(char *name, char *value,
+                                           void *data),
+                               void *data);
+errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
+                          void **value, unsigned int *value_len);
+errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
+                          const char *key,
+                          const void *value,
+                          unsigned int value_len);
+errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
+                             const char *key);
+errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
+                            struct ext2_xattr_handle **handle);
+errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle);
+errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
+                              struct ext2_inode_large *inode);
 
 /* extent.c */
 extern errcode_t ext2fs_extent_header_verify(void *ptr, int size);
index 9649a146423328f6aeda744d6cedc46abcf1b889..6eadca2326a43e9d65eb97b9abf06688a4beed10 100644 (file)
@@ -186,3 +186,760 @@ errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
        return ext2fs_adjust_ea_refcount2(fs, blk, block_buf, adjust,
                                          newcount);
 }
+
+/* Manipulate the contents of extended attribute regions */
+struct ext2_xattr {
+       char *name;
+       void *value;
+       unsigned int value_len;
+};
+
+struct ext2_xattr_handle {
+       ext2_filsys fs;
+       struct ext2_xattr *attrs;
+       unsigned int length;
+       ext2_ino_t ino;
+       int dirty;
+};
+
+errcode_t ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
+                              unsigned int expandby)
+{
+       struct ext2_xattr *new_attrs;
+       errcode_t err;
+
+       err = ext2fs_get_arrayzero(h->length + expandby,
+                                  sizeof(struct ext2_xattr), &new_attrs);
+       if (err)
+               return err;
+
+       memcpy(new_attrs, h->attrs, h->length * sizeof(struct ext2_xattr));
+       ext2fs_free_mem(&h->attrs);
+       h->length += expandby;
+       h->attrs = new_attrs;
+
+       return 0;
+}
+
+struct ea_name_index {
+       int index;
+       const char *name;
+};
+
+/* Keep these names sorted in order of decreasing specificity. */
+static struct ea_name_index ea_names[] = {
+       {3, "system.posix_acl_default"},
+       {2, "system.posix_acl_access"},
+       {8, "system.richacl"},
+       {6, "security."},
+       {4, "trusted."},
+       {7, "system."},
+       {1, "user."},
+       {0, NULL},
+};
+
+static const char *find_ea_prefix(int index)
+{
+       struct ea_name_index *e;
+
+       for (e = ea_names; e->name; e++)
+               if (e->index == index)
+                       return e->name;
+
+       return NULL;
+}
+
+static int find_ea_index(const char *fullname, char **name, int *index)
+{
+       struct ea_name_index *e;
+
+       for (e = ea_names; e->name; e++) {
+               if (memcmp(fullname, e->name, strlen(e->name)) == 0) {
+                       *name = (char *)fullname + strlen(e->name);
+                       *index = e->index;
+                       return 1;
+               }
+       }
+       return 0;
+}
+
+errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
+                              struct ext2_inode_large *inode)
+{
+       struct ext2_ext_attr_header *header;
+       void *block_buf = NULL;
+       dgrp_t grp;
+       blk64_t blk, goal;
+       errcode_t err;
+       struct ext2_inode_large i;
+
+       /* Read inode? */
+       if (inode == NULL) {
+               err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)&i,
+                                            sizeof(struct ext2_inode_large));
+               if (err)
+                       return err;
+               inode = &i;
+       }
+
+       /* Do we already have an EA block? */
+       blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
+       if (blk == 0)
+               return 0;
+
+       /* Find block, zero it, write back */
+       if ((blk < fs->super->s_first_data_block) ||
+           (blk >= ext2fs_blocks_count(fs->super))) {
+               err = EXT2_ET_BAD_EA_BLOCK_NUM;
+               goto out;
+       }
+
+       err = ext2fs_get_mem(fs->blocksize, &block_buf);
+       if (err)
+               goto out;
+
+       err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
+       if (err)
+               goto out2;
+
+       header = (struct ext2_ext_attr_header *) block_buf;
+       if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
+               err = EXT2_ET_BAD_EA_HEADER;
+               goto out2;
+       }
+
+       header->h_refcount--;
+       err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
+       if (err)
+               goto out2;
+
+       /* Erase link to block */
+       ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, 0);
+       if (header->h_refcount == 0)
+               ext2fs_block_alloc_stats2(fs, blk, -1);
+       err = ext2fs_iblk_sub_blocks(fs, (struct ext2_inode *)inode, 1);
+       if (err)
+               goto out2;
+
+       /* Write inode? */
+       if (inode == &i) {
+               err = ext2fs_write_inode_full(fs, ino, (struct ext2_inode *)&i,
+                                             sizeof(struct ext2_inode_large));
+               if (err)
+                       goto out2;
+       }
+
+out2:
+       ext2fs_free_mem(&block_buf);
+out:
+       return err;
+}
+
+static errcode_t prep_ea_block_for_write(ext2_filsys fs, ext2_ino_t ino,
+                                        struct ext2_inode_large *inode)
+{
+       struct ext2_ext_attr_header *header;
+       void *block_buf = NULL;
+       dgrp_t grp;
+       blk64_t blk, goal;
+       errcode_t err;
+
+       /* Do we already have an EA block? */
+       blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
+       if (blk != 0) {
+               if ((blk < fs->super->s_first_data_block) ||
+                   (blk >= ext2fs_blocks_count(fs->super))) {
+                       err = EXT2_ET_BAD_EA_BLOCK_NUM;
+                       goto out;
+               }
+
+               err = ext2fs_get_mem(fs->blocksize, &block_buf);
+               if (err)
+                       goto out;
+
+               err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
+               if (err)
+                       goto out2;
+
+               header = (struct ext2_ext_attr_header *) block_buf;
+               if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
+                       err = EXT2_ET_BAD_EA_HEADER;
+                       goto out2;
+               }
+
+               /* Single-user block.  We're done here. */
+               if (header->h_refcount == 1)
+                       goto out2;
+
+               /* We need to CoW the block. */
+               header->h_refcount--;
+               err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
+               if (err)
+                       goto out2;
+       } else {
+               /* No block, we must increment i_blocks */
+               err = ext2fs_iblk_add_blocks(fs, (struct ext2_inode *)inode,
+                                            1);
+               if (err)
+                       goto out;
+       }
+
+       /* Allocate a block */
+       grp = ext2fs_group_of_ino(fs, ino);
+       goal = ext2fs_inode_table_loc(fs, grp);
+       err = ext2fs_alloc_block2(fs, goal, NULL, &blk);
+       if (err)
+               goto out2;
+       ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, blk);
+out2:
+       if (block_buf)
+               ext2fs_free_mem(&block_buf);
+out:
+       return err;
+}
+
+
+static errcode_t write_xattrs_to_buffer(struct ext2_xattr_handle *handle,
+                                       struct ext2_xattr **pos,
+                                       void *entries_start,
+                                       unsigned int storage_size,
+                                       unsigned int value_offset_correction)
+{
+       struct ext2_xattr *x = *pos;
+       struct ext2_ext_attr_entry *e = entries_start;
+       void *end = entries_start + storage_size;
+       char *shortname;
+       unsigned int entry_size, value_size;
+       int idx, ret;
+
+       /* For all remaining x...  */
+       for (; x < handle->attrs + handle->length; x++) {
+               if (!x->name)
+                       continue;
+
+               /* Calculate index and shortname position */
+               shortname = x->name;
+               ret = find_ea_index(x->name, &shortname, &idx);
+
+               /* Calculate entry and value size */
+               entry_size = (sizeof(*e) + strlen(shortname) +
+                             EXT2_EXT_ATTR_PAD - 1) &
+                            ~(EXT2_EXT_ATTR_PAD - 1);
+               value_size = ((x->value_len + EXT2_EXT_ATTR_PAD - 1) /
+                             EXT2_EXT_ATTR_PAD) * EXT2_EXT_ATTR_PAD;
+
+               /*
+                * Would entry collide with value?
+                * Note that we must leave sufficient room for a (u32)0 to
+                * mark the end of the entries.
+                */
+               if ((void *)e + entry_size + sizeof(__u32) > end - value_size)
+                       break;
+
+               /* Fill out e appropriately */
+               e->e_name_len = strlen(shortname);
+               e->e_name_index = (ret ? idx : 0);
+               e->e_value_offs = end - value_size - (void *)entries_start +
+                               value_offset_correction;
+               e->e_value_block = 0;
+               e->e_value_size = x->value_len;
+
+               /* Store name and value */
+               end -= value_size;
+               memcpy((void *)e + sizeof(*e), shortname, e->e_name_len);
+               memcpy(end, x->value, e->e_value_size);
+
+               e->e_hash = ext2fs_ext_attr_hash_entry(e, end);
+
+               e = EXT2_EXT_ATTR_NEXT(e);
+               *(__u32 *)e = 0;
+       }
+       *pos = x;
+
+       return 0;
+}
+
+errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle)
+{
+       struct ext2_xattr *x;
+       struct ext2_inode_large *inode;
+       void *start, *block_buf = NULL;
+       struct ext2_ext_attr_header *header;
+       __u32 ea_inode_magic;
+       blk64_t blk;
+       unsigned int storage_size;
+       unsigned int i;
+       errcode_t err;
+
+       i = EXT2_INODE_SIZE(handle->fs->super);
+       if (i < sizeof(*inode))
+               i = sizeof(*inode);
+       err = ext2fs_get_memzero(i, &inode);
+       if (err)
+               return err;
+
+       err = ext2fs_read_inode_full(handle->fs, handle->ino,
+                                    (struct ext2_inode *)inode,
+                                    EXT2_INODE_SIZE(handle->fs->super));
+       if (err)
+               goto out;
+
+       x = handle->attrs;
+       /* Does the inode have size for EA? */
+       if (EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
+                                                 inode->i_extra_isize +
+                                                 sizeof(__u32))
+               goto write_ea_block;
+
+       /* Write the inode EA */
+       ea_inode_magic = EXT2_EXT_ATTR_MAGIC;
+       memcpy(((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
+              inode->i_extra_isize, &ea_inode_magic, sizeof(__u32));
+       storage_size = EXT2_INODE_SIZE(handle->fs->super) -
+               EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
+               sizeof(__u32);
+       start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
+               inode->i_extra_isize + sizeof(__u32);
+
+       err = write_xattrs_to_buffer(handle, &x, start, storage_size, 0);
+       if (err)
+               goto out;
+
+       /* Are we done? */
+       if (x == handle->attrs + handle->length)
+               goto skip_ea_block;
+
+write_ea_block:
+       /* Write the EA block */
+       err = ext2fs_get_memzero(handle->fs->blocksize, &block_buf);
+       if (err)
+               goto out;
+
+       storage_size = handle->fs->blocksize -
+               sizeof(struct ext2_ext_attr_header);
+       start = block_buf + sizeof(struct ext2_ext_attr_header);
+
+       err = write_xattrs_to_buffer(handle, &x, start, storage_size,
+                                    (void *)start - block_buf);
+       if (err)
+               goto out2;
+
+       if (x < handle->attrs + handle->length) {
+               err = EXT2_ET_EA_NO_SPACE;
+               goto out2;
+       }
+
+       /* Write a header on the EA block */
+       header = block_buf;
+       header->h_magic = EXT2_EXT_ATTR_MAGIC;
+       header->h_refcount = 1;
+       header->h_blocks = 1;
+
+       /* Get a new block for writing */
+       err = prep_ea_block_for_write(handle->fs, handle->ino, inode);
+       if (err)
+               goto out2;
+
+       /* Finally, write the new EA block */
+       blk = ext2fs_file_acl_block(handle->fs,
+                                   (struct ext2_inode *)inode);
+       err = ext2fs_write_ext_attr3(handle->fs, blk, block_buf,
+                                    handle->ino);
+       if (err)
+               goto out2;
+
+skip_ea_block:
+       blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
+       if (!block_buf && blk) {
+               /* xattrs shrunk, free the block */
+               err = ext2fs_free_ext_attr(handle->fs, handle->ino, inode);
+               if (err)
+                       goto out;
+       }
+
+       /* Write the inode */
+       err = ext2fs_write_inode_full(handle->fs, handle->ino,
+                                     (struct ext2_inode *)inode,
+                                     EXT2_INODE_SIZE(handle->fs->super));
+       if (err)
+               goto out2;
+
+out2:
+       ext2fs_free_mem(&block_buf);
+out:
+       ext2fs_free_mem(&inode);
+       handle->dirty = 0;
+       return err;
+}
+
+static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
+                                        struct ext2_ext_attr_entry *entries,
+                                        unsigned int storage_size,
+                                        void *value_start)
+{
+       struct ext2_xattr *x;
+       struct ext2_ext_attr_entry *entry;
+       const char *prefix;
+       void *ptr;
+       unsigned int remain, prefix_len;
+       errcode_t err;
+
+       x = handle->attrs;
+       while (x->name)
+               x++;
+
+       entry = entries;
+       while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
+               __u32 hash;
+
+               /* header eats this space */
+               remain -= sizeof(struct ext2_ext_attr_entry);
+
+               /* is attribute name valid? */
+               if (EXT2_EXT_ATTR_SIZE(entry->e_name_len) > remain)
+                       return EXT2_ET_EA_BAD_NAME_LEN;
+
+               /* attribute len eats this space */
+               remain -= EXT2_EXT_ATTR_SIZE(entry->e_name_len);
+
+               /* check value size */
+               if (entry->e_value_size > remain)
+                       return EXT2_ET_EA_BAD_VALUE_SIZE;
+
+               /* e_value_block must be 0 in inode's ea */
+               if (entry->e_value_block != 0)
+                       return EXT2_ET_BAD_EA_BLOCK_NUM;
+
+               hash = ext2fs_ext_attr_hash_entry(entry, value_start +
+                                                        entry->e_value_offs);
+
+               /* e_hash may be 0 in older inode's ea */
+               if (entry->e_hash != 0 && entry->e_hash != hash)
+                       return EXT2_ET_BAD_EA_HASH;
+
+               remain -= entry->e_value_size;
+
+               /* Allocate space for more attrs? */
+               if (x == handle->attrs + handle->length) {
+                       err = ext2fs_xattrs_expand(handle, 4);
+                       if (err)
+                               return err;
+                       x = handle->attrs + handle->length - 4;
+               }
+
+               /* Extract name/value */
+               prefix = find_ea_prefix(entry->e_name_index);
+               prefix_len = (prefix ? strlen(prefix) : 0);
+               err = ext2fs_get_memzero(entry->e_name_len + prefix_len + 1,
+                                        &x->name);
+               if (err)
+                       return err;
+               if (prefix)
+                       memcpy(x->name, prefix, prefix_len);
+               if (entry->e_name_len)
+                       memcpy(x->name + prefix_len,
+                              (void *)entry + sizeof(*entry),
+                              entry->e_name_len);
+
+               err = ext2fs_get_mem(entry->e_value_size, &x->value);
+               if (err)
+                       return err;
+               x->value_len = entry->e_value_size;
+               memcpy(x->value, value_start + entry->e_value_offs,
+                      entry->e_value_size);
+               x++;
+               entry = EXT2_EXT_ATTR_NEXT(entry);
+       }
+
+       return 0;
+}
+
+errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
+{
+       struct ext2_xattr *attrs = NULL, *x;
+       struct ext2_inode_large *inode;
+       struct ext2_ext_attr_header *header;
+       __u32 ea_inode_magic;
+       unsigned int storage_size;
+       void *start, *block_buf = NULL;
+       blk64_t blk;
+       int i;
+       errcode_t err;
+
+       i = EXT2_INODE_SIZE(handle->fs->super);
+       if (i < sizeof(*inode))
+               i = sizeof(*inode);
+       err = ext2fs_get_memzero(i, &inode);
+       if (err)
+               return err;
+
+       err = ext2fs_read_inode_full(handle->fs, handle->ino,
+                                    (struct ext2_inode *)inode,
+                                    EXT2_INODE_SIZE(handle->fs->super));
+       if (err)
+               goto out;
+
+       /* Does the inode have size for EA? */
+       if (EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
+                                                 inode->i_extra_isize +
+                                                 sizeof(__u32))
+               goto read_ea_block;
+
+       /* Look for EA in the inode */
+       memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
+              inode->i_extra_isize, sizeof(__u32));
+       if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
+               storage_size = EXT2_INODE_SIZE(handle->fs->super) -
+                       EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
+                       sizeof(__u32);
+               start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
+                       inode->i_extra_isize + sizeof(__u32);
+
+               err = read_xattrs_from_buffer(handle, start, storage_size,
+                                             start);
+               if (err)
+                       goto out;
+       }
+
+read_ea_block:
+       /* Look for EA in a separate EA block */
+       blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
+       if (blk != 0) {
+               if ((blk < handle->fs->super->s_first_data_block) ||
+                   (blk >= ext2fs_blocks_count(handle->fs->super))) {
+                       err = EXT2_ET_BAD_EA_BLOCK_NUM;
+                       goto out;
+               }
+
+               err = ext2fs_get_mem(handle->fs->blocksize, &block_buf);
+               if (err)
+                       goto out;
+
+               err = ext2fs_read_ext_attr3(handle->fs, blk, block_buf,
+                                           handle->ino);
+               if (err)
+                       goto out3;
+
+               header = (struct ext2_ext_attr_header *) block_buf;
+               if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
+                       err = EXT2_ET_BAD_EA_HEADER;
+                       goto out3;
+               }
+
+               if (header->h_blocks != 1) {
+                       err = EXT2_ET_BAD_EA_HEADER;
+                       goto out3;
+               }
+
+               /* Read EAs */
+               storage_size = handle->fs->blocksize -
+                       sizeof(struct ext2_ext_attr_header);
+               start = block_buf + sizeof(struct ext2_ext_attr_header);
+               err = read_xattrs_from_buffer(handle, start, storage_size,
+                                             block_buf);
+               if (err)
+                       goto out3;
+
+               ext2fs_free_mem(&block_buf);
+       }
+
+       ext2fs_free_mem(&block_buf);
+       ext2fs_free_mem(&inode);
+       return 0;
+
+out3:
+       ext2fs_free_mem(&block_buf);
+out:
+       ext2fs_free_mem(&inode);
+       return err;
+}
+
+errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
+                               int (*func)(char *name, char *value,
+                                           void *data),
+                               void *data)
+{
+       struct ext2_xattr *x;
+       errcode_t err;
+       int ret;
+
+       for (x = h->attrs; x < h->attrs + h->length; x++) {
+               if (!x->name)
+                       continue;
+
+               ret = func(x->name, x->value, data);
+               if (ret & XATTR_CHANGED)
+                       h->dirty = 1;
+               if (ret & XATTR_ABORT)
+                       return 0;
+       }
+
+       return 0;
+}
+
+errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
+                          void **value, unsigned int *value_len)
+{
+       struct ext2_xattr *x;
+       void *val;
+       errcode_t err;
+
+       for (x = h->attrs; x < h->attrs + h->length; x++) {
+               if (!x->name)
+                       continue;
+
+               if (strcmp(x->name, key) == 0) {
+                       err = ext2fs_get_mem(x->value_len, &val);
+                       if (err)
+                               return err;
+                       memcpy(val, x->value, x->value_len);
+                       *value = val;
+                       *value_len = x->value_len;
+                       return 0;
+               }
+       }
+
+       return EXT2_ET_EA_KEY_NOT_FOUND;
+}
+
+errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
+                          const char *key,
+                          const void *value,
+                          unsigned int value_len)
+{
+       struct ext2_xattr *x, *last_empty;
+       char *new_value;
+       errcode_t err;
+
+       last_empty = NULL;
+       for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
+               if (!x->name) {
+                       last_empty = x;
+                       continue;
+               }
+
+               /* Replace xattr */
+               if (strcmp(x->name, key) == 0) {
+                       err = ext2fs_get_mem(value_len, &new_value);
+                       if (err)
+                               return err;
+                       memcpy(new_value, value, value_len);
+                       ext2fs_free_mem(&x->value);
+                       x->value = new_value;
+                       x->value_len = value_len;
+                       handle->dirty = 1;
+                       return 0;
+               }
+       }
+
+       /* Add attr to empty slot */
+       if (last_empty) {
+               err = ext2fs_get_mem(strlen(key) + 1, &last_empty->name);
+               if (err)
+                       return err;
+               strcpy(last_empty->name, key);
+
+               err = ext2fs_get_mem(value_len, &last_empty->value);
+               if (err)
+                       return err;
+               memcpy(last_empty->value, value, value_len);
+               last_empty->value_len = value_len;
+               handle->dirty = 1;
+               return 0;
+       }
+
+       /* Expand array, append slot */
+       err = ext2fs_xattrs_expand(handle, 4);
+       if (err)
+               return err;
+
+       x = handle->attrs + handle->length - 4;
+       err = ext2fs_get_mem(strlen(key) + 1, &x->name);
+       if (err)
+               return err;
+       strcpy(x->name, key);
+
+       err = ext2fs_get_mem(value_len, &x->value);
+       if (err)
+               return err;
+       memcpy(x->value, value, value_len);
+       x->value_len = value_len;
+       handle->dirty = 1;
+       return 0;
+}
+
+errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
+                             const char *key)
+{
+       struct ext2_xattr *x;
+       errcode_t err;
+
+       for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
+               if (!x->name)
+                       continue;
+
+               if (strcmp(x->name, key) == 0) {
+                       ext2fs_free_mem(&x->name);
+                       ext2fs_free_mem(&x->value);
+                       x->value_len = 0;
+                       handle->dirty = 1;
+                       return 0;
+               }
+       }
+
+       return EXT2_ET_EA_KEY_NOT_FOUND;
+}
+
+errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
+                            struct ext2_xattr_handle **handle)
+{
+       struct ext2_xattr_handle *h;
+       errcode_t err;
+
+       if (!EXT2_HAS_COMPAT_FEATURE(fs->super,
+                                    EXT2_FEATURE_COMPAT_EXT_ATTR) &&
+           !EXT2_HAS_INCOMPAT_FEATURE(fs->super,
+                                    EXT4_FEATURE_INCOMPAT_INLINE_DATA))
+               return EXT2_ET_MISSING_EA_FEATURE;
+
+       err = ext2fs_get_memzero(sizeof(*h), &h);
+       if (err)
+               return err;
+
+       h->length = 4;
+       err = ext2fs_get_arrayzero(h->length, sizeof(struct ext2_xattr),
+                                  &h->attrs);
+       if (err) {
+               ext2fs_free_mem(&h);
+               return err;
+       }
+       h->ino = ino;
+       h->fs = fs;
+       *handle = h;
+       return 0;
+}
+
+errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle)
+{
+       unsigned int i;
+       struct ext2_xattr_handle *h = *handle;
+       struct ext2_xattr *a = h->attrs;
+       errcode_t err;
+
+       if (h->dirty) {
+               err = ext2fs_xattrs_write(h);
+               if (err)
+                       return err;
+       }
+
+       for (i = 0; i < h->length; i++) {
+               if (a[i].name)
+                       ext2fs_free_mem(&a[i].name);
+               if (a[i].value)
+                       ext2fs_free_mem(&a[i].value);
+       }
+
+       ext2fs_free_mem(&h->attrs);
+       ext2fs_free_mem(handle);
+       return 0;
+}