Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 745 insertions, 0 deletions

diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
new file mode 100644
index 000000000..3db8486e3
--- /dev/null
+++ b/fs/ubifs/xattr.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/*
+ * This file implements UBIFS extended attributes support.
+ *
+ * Extended attributes are implemented as regular inodes with attached data,
+ * which limits extended attribute size to UBIFS block size (4KiB). Names of
+ * extended attributes are described by extended attribute entries (xentries),
+ * which are almost identical to directory entries, but have different key type.
+ *
+ * In other words, the situation with extended attributes is very similar to
+ * directories. Indeed, any inode (but of course not xattr inodes) may have a
+ * number of associated xentries, just like directory inodes have associated
+ * directory entries. Extended attribute entries store the name of the extended
+ * attribute, the host inode number, and the extended attribute inode number.
+ * Similarly, direntries store the name, the parent and the target inode
+ * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
+ * extended attributes.
+ *
+ * The number of extended attributes is not limited, but there is Linux
+ * limitation on the maximum possible size of the list of all extended
+ * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
+ * the sum of all extended attribute names of the inode does not exceed that
+ * limit.
+ *
+ * Extended attributes are synchronous, which means they are written to the
+ * flash media synchronously and there is no write-back for extended attribute
+ * inodes. The extended attribute values are not stored in compressed form on
+ * the media.
+ *
+ * Since extended attributes are represented by regular inodes, they are cached
+ * in the VFS inode cache. The xentries are cached in the LNC cache (see
+ * tnc.c).
+ *
+ * ACL support is not implemented.
+ */
+
+#include "ubifs.h"
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+
+/*
+ * Extended attribute type constants.
+ *
+ * USER_XATTR: user extended attribute ("user.*")
+ * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
+ * SECURITY_XATTR: security extended attribute ("security.*")
+ */
+enum {
+	USER_XATTR,
+	TRUSTED_XATTR,
+	SECURITY_XATTR,
+};
+
+static const struct inode_operations empty_iops;
+static const struct file_operations empty_fops;
+
+/**
+ * create_xattr - create an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @nm: extended attribute name
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This is a helper function which creates an extended attribute of name @nm
+ * and value @value for inode @host. The host inode is also updated on flash
+ * because the ctime and extended attribute accounting data changes. This
+ * function returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int create_xattr(struct ubifs_info *c, struct inode *host,
+			const struct fscrypt_name *nm, const void *value, int size)
+{
+	int err, names_len;
+	struct inode *inode;
+	struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
+	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+				.new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
+				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+	if (host_ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) {
+		ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more",
+			  host->i_ino, host_ui->xattr_cnt);
+		return -ENOSPC;
+	}
+	/*
+	 * Linux limits the maximum size of the extended attribute names list
+	 * to %XATTR_LIST_MAX. This means we should not allow creating more
+	 * extended attributes if the name list becomes larger. This limitation
+	 * is artificial for UBIFS, though.
+	 */
+	names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1;
+	if (names_len > XATTR_LIST_MAX) {
+		ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
+			  host->i_ino, names_len, XATTR_LIST_MAX);
+		return -ENOSPC;
+	}
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO, true);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_budg;
+	}
+
+	/* Re-define all operations to be "nothing" */
+	inode->i_mapping->a_ops = &empty_aops;
+	inode->i_op = &empty_iops;
+	inode->i_fop = &empty_fops;
+
+	inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME;
+	ui = ubifs_inode(inode);
+	ui->xattr = 1;
+	ui->flags |= UBIFS_XATTR_FL;
+	ui->data = kmemdup(value, size, GFP_NOFS);
+	if (!ui->data) {
+		err = -ENOMEM;
+		goto out_free;
+	}
+	inode->i_size = ui->ui_size = size;
+	ui->data_len = size;
+
+	mutex_lock(&host_ui->ui_mutex);
+	host->i_ctime = current_time(host);
+	host_ui->xattr_cnt += 1;
+	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+	host_ui->xattr_size += CALC_XATTR_BYTES(size);
+	host_ui->xattr_names += fname_len(nm);
+
+	/*
+	 * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we
+	 * have to set the UBIFS_CRYPT_FL flag on the host inode.
+	 * To avoid multiple updates of the same inode in the same operation,
+	 * let's do it here.
+	 */
+	if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+		host_ui->flags |= UBIFS_CRYPT_FL;
+
+	err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
+	if (err)
+		goto out_cancel;
+	ubifs_set_inode_flags(host);
+	mutex_unlock(&host_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	insert_inode_hash(inode);
+	iput(inode);
+	return 0;
+
+out_cancel:
+	host_ui->xattr_cnt -= 1;
+	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+	host_ui->xattr_names -= fname_len(nm);
+	host_ui->flags &= ~UBIFS_CRYPT_FL;
+	mutex_unlock(&host_ui->ui_mutex);
+out_free:
+	make_bad_inode(inode);
+	iput(inode);
+out_budg:
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+/**
+ * change_xattr - change an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @inode: extended attribute inode
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This helper function changes the value of extended attribute @inode with new
+ * data from @value. Returns zero in case of success and a negative error code
+ * in case of failure.
+ */
+static int change_xattr(struct ubifs_info *c, struct inode *host,
+			struct inode *inode, const void *value, int size)
+{
+	int err;
+	struct ubifs_inode *host_ui = ubifs_inode(host);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	void *buf = NULL;
+	int old_size;
+	struct ubifs_budget_req req = { .dirtied_ino = 2,
+		.dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
+
+	ubifs_assert(c, ui->data_len == inode->i_size);
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	buf = kmemdup(value, size, GFP_NOFS);
+	if (!buf) {
+		err = -ENOMEM;
+		goto out_free;
+	}
+	kfree(ui->data);
+	ui->data = buf;
+	inode->i_size = ui->ui_size = size;
+	old_size = ui->data_len;
+	ui->data_len = size;
+
+	mutex_lock(&host_ui->ui_mutex);
+	host->i_ctime = current_time(host);
+	host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
+	host_ui->xattr_size += CALC_XATTR_BYTES(size);
+
+	/*
+	 * It is important to write the host inode after the xattr inode
+	 * because if the host inode gets synchronized (via 'fsync()'), then
+	 * the extended attribute inode gets synchronized, because it goes
+	 * before the host inode in the write-buffer.
+	 */
+	err = ubifs_jnl_change_xattr(c, inode, host);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&host_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	return 0;
+
+out_cancel:
+	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+	host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
+	mutex_unlock(&host_ui->ui_mutex);
+	make_bad_inode(inode);
+out_free:
+	ubifs_release_budget(c, &req);
+	return err;
+}
+
+static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
+{
+	struct inode *inode;
+
+	inode = ubifs_iget(c->vfs_sb, inum);
+	if (IS_ERR(inode)) {
+		ubifs_err(c, "dead extended attribute entry, error %d",
+			  (int)PTR_ERR(inode));
+		return inode;
+	}
+	if (ubifs_inode(inode)->xattr)
+		return inode;
+	ubifs_err(c, "corrupt extended attribute entry");
+	iput(inode);
+	return ERR_PTR(-EINVAL);
+}
+
+int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
+		    size_t size, int flags, bool check_lock)
+{
+	struct inode *inode;
+	struct ubifs_info *c = host->i_sb->s_fs_info;
+	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+	struct ubifs_dent_node *xent;
+	union ubifs_key key;
+	int err;
+
+	if (check_lock)
+		ubifs_assert(c, inode_is_locked(host));
+
+	if (size > UBIFS_MAX_INO_DATA)
+		return -ERANGE;
+
+	if (fname_len(&nm) > UBIFS_MAX_NLEN)
+		return -ENAMETOOLONG;
+
+	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+	if (!xent)
+		return -ENOMEM;
+
+	down_write(&ubifs_inode(host)->xattr_sem);
+	/*
+	 * The extended attribute entries are stored in LNC, so multiple
+	 * look-ups do not involve reading the flash.
+	 */
+	xent_key_init(c, &key, host->i_ino, &nm);
+	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+	if (err) {
+		if (err != -ENOENT)
+			goto out_free;
+
+		if (flags & XATTR_REPLACE)
+			/* We are asked not to create the xattr */
+			err = -ENODATA;
+		else
+			err = create_xattr(c, host, &nm, value, size);
+		goto out_free;
+	}
+
+	if (flags & XATTR_CREATE) {
+		/* We are asked not to replace the xattr */
+		err = -EEXIST;
+		goto out_free;
+	}
+
+	inode = iget_xattr(c, le64_to_cpu(xent->inum));
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_free;
+	}
+
+	err = change_xattr(c, host, inode, value, size);
+	iput(inode);
+
+out_free:
+	up_write(&ubifs_inode(host)->xattr_sem);
+	kfree(xent);
+	return err;
+}
+
+ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
+			size_t size)
+{
+	struct inode *inode;
+	struct ubifs_info *c = host->i_sb->s_fs_info;
+	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+	struct ubifs_inode *ui;
+	struct ubifs_dent_node *xent;
+	union ubifs_key key;
+	int err;
+
+	if (fname_len(&nm) > UBIFS_MAX_NLEN)
+		return -ENAMETOOLONG;
+
+	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+	if (!xent)
+		return -ENOMEM;
+
+	down_read(&ubifs_inode(host)->xattr_sem);
+	xent_key_init(c, &key, host->i_ino, &nm);
+	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+	if (err) {
+		if (err == -ENOENT)
+			err = -ENODATA;
+		goto out_cleanup;
+	}
+
+	inode = iget_xattr(c, le64_to_cpu(xent->inum));
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_cleanup;
+	}
+
+	ui = ubifs_inode(inode);
+	ubifs_assert(c, inode->i_size == ui->data_len);
+	ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
+
+	if (buf) {
+		/* If @buf is %NULL we are supposed to return the length */
+		if (ui->data_len > size) {
+			err = -ERANGE;
+			goto out_iput;
+		}
+
+		memcpy(buf, ui->data, ui->data_len);
+	}
+	err = ui->data_len;
+
+out_iput:
+	iput(inode);
+out_cleanup:
+	up_read(&ubifs_inode(host)->xattr_sem);
+	kfree(xent);
+	return err;
+}
+
+static bool xattr_visible(const char *name)
+{
+	/* File encryption related xattrs are for internal use only */
+	if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+		return false;
+
+	/* Show trusted namespace only for "power" users */
+	if (strncmp(name, XATTR_TRUSTED_PREFIX,
+		    XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN))
+		return false;
+
+	return true;
+}
+
+ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+	union ubifs_key key;
+	struct inode *host = d_inode(dentry);
+	struct ubifs_info *c = host->i_sb->s_fs_info;
+	struct ubifs_inode *host_ui = ubifs_inode(host);
+	struct ubifs_dent_node *xent, *pxent = NULL;
+	int err, len, written = 0;
+	struct fscrypt_name nm = {0};
+
+	dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
+		dentry, size);
+
+	down_read(&host_ui->xattr_sem);
+	len = host_ui->xattr_names + host_ui->xattr_cnt;
+	if (!buffer) {
+		/*
+		 * We should return the minimum buffer size which will fit a
+		 * null-terminated list of all the extended attribute names.
+		 */
+		err = len;
+		goto out_err;
+	}
+
+	if (len > size) {
+		err = -ERANGE;
+		goto out_err;
+	}
+
+	lowest_xent_key(c, &key, host->i_ino);
+	while (1) {
+		xent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(xent)) {
+			err = PTR_ERR(xent);
+			break;
+		}
+
+		fname_name(&nm) = xent->name;
+		fname_len(&nm) = le16_to_cpu(xent->nlen);
+
+		if (xattr_visible(xent->name)) {
+			memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1);
+			written += fname_len(&nm) + 1;
+		}
+
+		kfree(pxent);
+		pxent = xent;
+		key_read(c, &xent->key, &key);
+	}
+	kfree(pxent);
+	up_read(&host_ui->xattr_sem);
+
+	if (err != -ENOENT) {
+		ubifs_err(c, "cannot find next direntry, error %d", err);
+		return err;
+	}
+
+	ubifs_assert(c, written <= size);
+	return written;
+
+out_err:
+	up_read(&host_ui->xattr_sem);
+	return err;
+}
+
+static int remove_xattr(struct ubifs_info *c, struct inode *host,
+			struct inode *inode, const struct fscrypt_name *nm)
+{
+	int err;
+	struct ubifs_inode *host_ui = ubifs_inode(host);
+	struct ubifs_inode *ui = ubifs_inode(inode);
+	struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
+				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+	ubifs_assert(c, ui->data_len == inode->i_size);
+
+	err = ubifs_budget_space(c, &req);
+	if (err)
+		return err;
+
+	mutex_lock(&host_ui->ui_mutex);
+	host->i_ctime = current_time(host);
+	host_ui->xattr_cnt -= 1;
+	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+	host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
+	host_ui->xattr_names -= fname_len(nm);
+
+	err = ubifs_jnl_delete_xattr(c, host, inode, nm);
+	if (err)
+		goto out_cancel;
+	mutex_unlock(&host_ui->ui_mutex);
+
+	ubifs_release_budget(c, &req);
+	return 0;
+
+out_cancel:
+	host_ui->xattr_cnt += 1;
+	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
+	host_ui->xattr_names += fname_len(nm);
+	mutex_unlock(&host_ui->ui_mutex);
+	ubifs_release_budget(c, &req);
+	make_bad_inode(inode);
+	return err;
+}
+
+int ubifs_purge_xattrs(struct inode *host)
+{
+	union ubifs_key key;
+	struct ubifs_info *c = host->i_sb->s_fs_info;
+	struct ubifs_dent_node *xent, *pxent = NULL;
+	struct inode *xino;
+	struct fscrypt_name nm = {0};
+	int err;
+
+	if (ubifs_inode(host)->xattr_cnt <= ubifs_xattr_max_cnt(c))
+		return 0;
+
+	ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion",
+		   host->i_ino);
+
+	down_write(&ubifs_inode(host)->xattr_sem);
+	lowest_xent_key(c, &key, host->i_ino);
+	while (1) {
+		xent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(xent)) {
+			err = PTR_ERR(xent);
+			break;
+		}
+
+		fname_name(&nm) = xent->name;
+		fname_len(&nm) = le16_to_cpu(xent->nlen);
+
+		xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum));
+		if (IS_ERR(xino)) {
+			err = PTR_ERR(xino);
+			ubifs_err(c, "dead directory entry '%s', error %d",
+				  xent->name, err);
+			ubifs_ro_mode(c, err);
+			kfree(pxent);
+			kfree(xent);
+			goto out_err;
+		}
+
+		ubifs_assert(c, ubifs_inode(xino)->xattr);
+
+		clear_nlink(xino);
+		err = remove_xattr(c, host, xino, &nm);
+		if (err) {
+			kfree(pxent);
+			kfree(xent);
+			iput(xino);
+			ubifs_err(c, "cannot remove xattr, error %d", err);
+			goto out_err;
+		}
+
+		iput(xino);
+
+		kfree(pxent);
+		pxent = xent;
+		key_read(c, &xent->key, &key);
+	}
+	kfree(pxent);
+	up_write(&ubifs_inode(host)->xattr_sem);
+
+	if (err != -ENOENT) {
+		ubifs_err(c, "cannot find next direntry, error %d", err);
+		return err;
+	}
+
+	return 0;
+
+out_err:
+	up_write(&ubifs_inode(host)->xattr_sem);
+	return err;
+}
+
+/**
+ * ubifs_evict_xattr_inode - Evict an xattr inode.
+ * @c: UBIFS file-system description object
+ * @xattr_inum: xattr inode number
+ *
+ * When an inode that hosts xattrs is being removed we have to make sure
+ * that cached inodes of the xattrs also get removed from the inode cache
+ * otherwise we'd waste memory. This function looks up an inode from the
+ * inode cache and clears the link counter such that iput() will evict
+ * the inode.
+ */
+void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum)
+{
+	struct inode *inode;
+
+	inode = ilookup(c->vfs_sb, xattr_inum);
+	if (inode) {
+		clear_nlink(inode);
+		iput(inode);
+	}
+}
+
+static int ubifs_xattr_remove(struct inode *host, const char *name)
+{
+	struct inode *inode;
+	struct ubifs_info *c = host->i_sb->s_fs_info;
+	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+	struct ubifs_dent_node *xent;
+	union ubifs_key key;
+	int err;
+
+	ubifs_assert(c, inode_is_locked(host));
+
+	if (fname_len(&nm) > UBIFS_MAX_NLEN)
+		return -ENAMETOOLONG;
+
+	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+	if (!xent)
+		return -ENOMEM;
+
+	down_write(&ubifs_inode(host)->xattr_sem);
+	xent_key_init(c, &key, host->i_ino, &nm);
+	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+	if (err) {
+		if (err == -ENOENT)
+			err = -ENODATA;
+		goto out_free;
+	}
+
+	inode = iget_xattr(c, le64_to_cpu(xent->inum));
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out_free;
+	}
+
+	ubifs_assert(c, inode->i_nlink == 1);
+	clear_nlink(inode);
+	err = remove_xattr(c, host, inode, &nm);
+	if (err)
+		set_nlink(inode, 1);
+
+	/* If @i_nlink is 0, 'iput()' will delete the inode */
+	iput(inode);
+
+out_free:
+	up_write(&ubifs_inode(host)->xattr_sem);
+	kfree(xent);
+	return err;
+}
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
+		      void *fs_info)
+{
+	const struct xattr *xattr;
+	char *name;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
+			       strlen(xattr->name) + 1, GFP_NOFS);
+		if (!name) {
+			err = -ENOMEM;
+			break;
+		}
+		strcpy(name, XATTR_SECURITY_PREFIX);
+		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
+		/*
+		 * creating a new inode without holding the inode rwsem,
+		 * no need to check whether inode is locked.
+		 */
+		err = ubifs_xattr_set(inode, name, xattr->value,
+				      xattr->value_len, 0, false);
+		kfree(name);
+		if (err < 0)
+			break;
+	}
+
+	return err;
+}
+
+int ubifs_init_security(struct inode *dentry, struct inode *inode,
+			const struct qstr *qstr)
+{
+	int err;
+
+	err = security_inode_init_security(inode, dentry, qstr,
+					   &init_xattrs, NULL);
+	if (err) {
+		struct ubifs_info *c = dentry->i_sb->s_fs_info;
+		ubifs_err(c, "cannot initialize security for inode %lu, error %d",
+			  inode->i_ino, err);
+	}
+	return err;
+}
+#endif
+
+static int xattr_get(const struct xattr_handler *handler,
+			   struct dentry *dentry, struct inode *inode,
+			   const char *name, void *buffer, size_t size)
+{
+	dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
+		inode->i_ino, dentry, size);
+
+	name = xattr_full_name(handler, name);
+	return ubifs_xattr_get(inode, name, buffer, size);
+}
+
+static int xattr_set(const struct xattr_handler *handler,
+			   struct user_namespace *mnt_userns,
+			   struct dentry *dentry, struct inode *inode,
+			   const char *name, const void *value,
+			   size_t size, int flags)
+{
+	dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
+		name, inode->i_ino, dentry, size);
+
+	name = xattr_full_name(handler, name);
+
+	if (value)
+		return ubifs_xattr_set(inode, name, value, size, flags, true);
+	else
+		return ubifs_xattr_remove(inode, name);
+}
+
+static const struct xattr_handler ubifs_user_xattr_handler = {
+	.prefix = XATTR_USER_PREFIX,
+	.get = xattr_get,
+	.set = xattr_set,
+};
+
+static const struct xattr_handler ubifs_trusted_xattr_handler = {
+	.prefix = XATTR_TRUSTED_PREFIX,
+	.get = xattr_get,
+	.set = xattr_set,
+};
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static const struct xattr_handler ubifs_security_xattr_handler = {
+	.prefix = XATTR_SECURITY_PREFIX,
+	.get = xattr_get,
+	.set = xattr_set,
+};
+#endif
+
+const struct xattr_handler *ubifs_xattr_handlers[] = {
+	&ubifs_user_xattr_handler,
+	&ubifs_trusted_xattr_handler,
+#ifdef CONFIG_UBIFS_FS_SECURITY
+	&ubifs_security_xattr_handler,
+#endif
+	NULL
+};