Merge tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull libfs and tmpfs updates from Christian Brauner:
 "This cycle saw a lot of work for tmpfs that required changes to the
  vfs layer. Andrew, Hugh, and I decided to take tmpfs through vfs this
  cycle. Things will go back to mm next cycle.

  Features
  ========

   - By far the biggest work is the quota support for tmpfs. New tmpfs
     quota infrastructure is added to support it and a new QFMT_SHMEM
     uapi option is exposed.

     This offers user and group quotas to tmpfs (project quotas will be
     added later). Similar to other filesystems tmpfs quota are not
     supported within user namespaces yet.

   - Add support for user xattrs. While tmpfs already supports security
     xattrs (security.*) and POSIX ACLs for a long time it lacked
     support for user xattrs (user.*). With this pull request tmpfs will
     be able to support a limited number of user xattrs.

     This is accompanied by a fix (see below) to limit persistent simple
     xattr allocations.

   - Add support for stable directory offsets. Currently tmpfs relies on
     the libfs provided cursor-based mechanism for readdir. This causes
     issues when a tmpfs filesystem is exported via NFS.

     NFS clients do not open directories. Instead, each server-side
     readdir operation opens the directory, reads it, and then closes
     it. Since the cursor state for that directory is associated with
     the opened file it is discarded after each readdir operation. Such
     directory offsets are not just cached by NFS clients but also
     various userspace libraries based on these clients.

     As it stands there is no way to invalidate the caches when
     directory offsets have changed and the whole application depends on
     unchanging directory offsets.

     At LSFMM we discussed how to solve this problem and decided to
     support stable directory offsets. libfs now allows filesystems like
     tmpfs to use an xarrary to map a directory offset to a dentry. This
     mechanism is currently only used by tmpfs but can be supported by
     others as well.

  Fixes
  =====

   - Change persistent simple xattrs allocations in libfs from
     GFP_KERNEL to GPF_KERNEL_ACCOUNT so they're subject to memory
     cgroup limits. Since this is a change to libfs it affects both
     tmpfs and kernfs.

   - Correctly verify {g,u}id mount options.

     A new filesystem context is created via fsopen() which records the
     namespace that becomes the owning namespace of the superblock when
     fsconfig(FSCONFIG_CMD_CREATE) is called for filesystems that are
     mountable in namespaces. However, fsconfig() calls can occur in a
     namespace different from the namespace where fsopen() has been
     called.

     Currently, when fsconfig() is called to set {g,u}id mount options
     the requested {g,u}id is mapped into a k{g,u}id according to the
     namespace where fsconfig() was called from. The resulting k{g,u}id
     is not guaranteed to be resolvable in the namespace of the
     filesystem (the one that fsopen() was called in).

     This means it's possible for an unprivileged user to create files
     owned by any group in a tmpfs mount since it's possible to set the
     setid bits on the tmpfs directory.

     The contract for {g,u}id mount options and {g,u}id values in
     general set from userspace has always been that they are translated
     according to the caller's idmapping. In so far, tmpfs has been
     doing the correct thing. But since tmpfs is mountable in
     unprivileged contexts it is also necessary to verify that the
     resulting {k,g}uid is representable in the namespace of the
     superblock to avoid such bugs.

     The new mount api's cross-namespace delegation abilities are
     already widely used. Having talked to a bunch of userspace this is
     the most faithful solution with minimal regression risks"

* tag 'v6.6-vfs.tmpfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs
  mm: invalidation check mapping before folio_contains
  tmpfs: trivial support for direct IO
  tmpfs,xattr: enable limited user extended attributes
  tmpfs: track free_ispace instead of free_inodes
  xattr: simple_xattr_set() return old_xattr to be freed
  tmpfs: verify {g,u}id mount options correctly
  shmem: move spinlock into shmem_recalc_inode() to fix quota support
  libfs: Remove parent dentry locking in offset_iterate_dir()
  libfs: Add a lock class for the offset map's xa_lock
  shmem: stable directory offsets
  shmem: Refactor shmem_symlink()
  libfs: Add directory operations for stable offsets
  shmem: fix quota lock nesting in huge hole handling
  shmem: Add default quota limit mount options
  shmem: quota support
  shmem: prepare shmem quota infrastructure
  quota: Check presence of quota operation structures instead of ->quota_read and ->quota_write callbacks
  shmem: make shmem_get_inode() return ERR_PTR instead of NULL
  shmem: make shmem_inode_acct_block() return error

6 files changed, 344 insertions, 53 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 18d034ec7953..7da21f563192 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -205,8 +205,8 @@ config TMPFS_XATTR
 	  Extended attributes are name:value pairs associated with inodes by
 	  the kernel or by users (see the attr(5) manual page for details).
 
-	  Currently this enables support for the trusted.* and
-	  security.* namespaces.
+	  This enables support for the trusted.*, security.* and user.*
+	  namespaces.
 
 	  You need this for POSIX ACL support on tmpfs.
 
@@ -233,6 +233,18 @@ config TMPFS_INODE64
 
 	  If unsure, say N.
 
+config TMPFS_QUOTA
+	bool "Tmpfs quota support"
+	depends on TMPFS
+	select QUOTA
+	help
+	  Quota support allows to set per user and group limits for tmpfs
+	  usage.  Say Y to enable quota support. Once enabled you can control
+	  user and group quota enforcement with quota, usrquota and grpquota
+	  mount options.
+
+	  If unsure, say N.
+
 config ARCH_SUPPORTS_HUGETLBFS
 	def_bool n
 
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 5a1a4af9d3d2..660995856a04 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -556,7 +556,7 @@ void kernfs_put(struct kernfs_node *kn)
 	kfree_const(kn->name);
 
 	if (kn->iattr) {
-		simple_xattrs_free(&kn->iattr->xattrs);
+		simple_xattrs_free(&kn->iattr->xattrs, NULL);
 		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
 	}
 	spin_lock(&kernfs_idr_lock);
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index af37be68bf06..922719a343a7 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -305,11 +305,17 @@ int kernfs_xattr_get(struct kernfs_node *kn, const char *name,
 int kernfs_xattr_set(struct kernfs_node *kn, const char *name,
 		     const void *value, size_t size, int flags)
 {
+	struct simple_xattr *old_xattr;
 	struct kernfs_iattrs *attrs = kernfs_iattrs(kn);
 	if (!attrs)
 		return -ENOMEM;
 
-	return simple_xattr_set(&attrs->xattrs, name, value, size, flags, NULL);
+	old_xattr = simple_xattr_set(&attrs->xattrs, name, value, size, flags);
+	if (IS_ERR(old_xattr))
+		return PTR_ERR(old_xattr);
+
+	simple_xattr_free(old_xattr);
+	return 0;
 }
 
 static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
@@ -341,7 +347,7 @@ static int kernfs_vfs_user_xattr_add(struct kernfs_node *kn,
 {
 	atomic_t *sz = &kn->iattr->user_xattr_size;
 	atomic_t *nr = &kn->iattr->nr_user_xattrs;
-	ssize_t removed_size;
+	struct simple_xattr *old_xattr;
 	int ret;
 
 	if (atomic_inc_return(nr) > KERNFS_MAX_USER_XATTRS) {
@@ -354,13 +360,18 @@ static int kernfs_vfs_user_xattr_add(struct kernfs_node *kn,
 		goto dec_size_out;
 	}
 
-	ret = simple_xattr_set(xattrs, full_name, value, size, flags,
-			       &removed_size);
-
-	if (!ret && removed_size >= 0)
-		size = removed_size;
-	else if (!ret)
+	old_xattr = simple_xattr_set(xattrs, full_name, value, size, flags);
+	if (!old_xattr)
 		return 0;
+
+	if (IS_ERR(old_xattr)) {
+		ret = PTR_ERR(old_xattr);
+		goto dec_size_out;
+	}
+
+	ret = 0;
+	size = old_xattr->size;
+	simple_xattr_free(old_xattr);
 dec_size_out:
 	atomic_sub(size, sz);
 dec_count_out:
@@ -375,18 +386,19 @@ static int kernfs_vfs_user_xattr_rm(struct kernfs_node *kn,
 {
 	atomic_t *sz = &kn->iattr->user_xattr_size;
 	atomic_t *nr = &kn->iattr->nr_user_xattrs;
-	ssize_t removed_size;
-	int ret;
+	struct simple_xattr *old_xattr;
 
-	ret = simple_xattr_set(xattrs, full_name, value, size, flags,
-			       &removed_size);
+	old_xattr = simple_xattr_set(xattrs, full_name, value, size, flags);
+	if (!old_xattr)
+		return 0;
 
-	if (removed_size >= 0) {
-		atomic_sub(removed_size, sz);
-		atomic_dec(nr);
-	}
+	if (IS_ERR(old_xattr))
+		return PTR_ERR(old_xattr);
 
-	return ret;
+	atomic_sub(old_xattr->size, sz);
+	atomic_dec(nr);
+	simple_xattr_free(old_xattr);
+	return 0;
 }
 
 static int kernfs_vfs_user_xattr_set(const struct xattr_handler *handler,
diff --git a/fs/libfs.c b/fs/libfs.c
index a61878469dcd..2263d353855d 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -239,6 +239,254 @@ const struct inode_operations simple_dir_inode_operations = {
 };
 EXPORT_SYMBOL(simple_dir_inode_operations);
 
+static void offset_set(struct dentry *dentry, u32 offset)
+{
+	dentry->d_fsdata = (void *)((uintptr_t)(offset));
+}
+
+static u32 dentry2offset(struct dentry *dentry)
+{
+	return (u32)((uintptr_t)(dentry->d_fsdata));
+}
+
+static struct lock_class_key simple_offset_xa_lock;
+
+/**
+ * simple_offset_init - initialize an offset_ctx
+ * @octx: directory offset map to be initialized
+ *
+ */
+void simple_offset_init(struct offset_ctx *octx)
+{
+	xa_init_flags(&octx->xa, XA_FLAGS_ALLOC1);
+	lockdep_set_class(&octx->xa.xa_lock, &simple_offset_xa_lock);
+
+	/* 0 is '.', 1 is '..', so always start with offset 2 */
+	octx->next_offset = 2;
+}
+
+/**
+ * simple_offset_add - Add an entry to a directory's offset map
+ * @octx: directory offset ctx to be updated
+ * @dentry: new dentry being added
+ *
+ * Returns zero on success. @so_ctx and the dentry offset are updated.
+ * Otherwise, a negative errno value is returned.
+ */
+int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry)
+{
+	static const struct xa_limit limit = XA_LIMIT(2, U32_MAX);
+	u32 offset;
+	int ret;
+
+	if (dentry2offset(dentry) != 0)
+		return -EBUSY;
+
+	ret = xa_alloc_cyclic(&octx->xa, &offset, dentry, limit,
+			      &octx->next_offset, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+
+	offset_set(dentry, offset);
+	return 0;
+}
+
+/**
+ * simple_offset_remove - Remove an entry to a directory's offset map
+ * @octx: directory offset ctx to be updated
+ * @dentry: dentry being removed
+ *
+ */
+void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry)
+{
+	u32 offset;
+
+	offset = dentry2offset(dentry);
+	if (offset == 0)
+		return;
+
+	xa_erase(&octx->xa, offset);
+	offset_set(dentry, 0);
+}
+
+/**
+ * simple_offset_rename_exchange - exchange rename with directory offsets
+ * @old_dir: parent of dentry being moved
+ * @old_dentry: dentry being moved
+ * @new_dir: destination parent
+ * @new_dentry: destination dentry
+ *
+ * Returns zero on success. Otherwise a negative errno is returned and the
+ * rename is rolled back.
+ */
+int simple_offset_rename_exchange(struct inode *old_dir,
+				  struct dentry *old_dentry,
+				  struct inode *new_dir,
+				  struct dentry *new_dentry)
+{
+	struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir);
+	struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir);
+	u32 old_index = dentry2offset(old_dentry);
+	u32 new_index = dentry2offset(new_dentry);
+	int ret;
+
+	simple_offset_remove(old_ctx, old_dentry);
+	simple_offset_remove(new_ctx, new_dentry);
+
+	ret = simple_offset_add(new_ctx, old_dentry);
+	if (ret)
+		goto out_restore;
+
+	ret = simple_offset_add(old_ctx, new_dentry);
+	if (ret) {
+		simple_offset_remove(new_ctx, old_dentry);
+		goto out_restore;
+	}
+
+	ret = simple_rename_exchange(old_dir, old_dentry, new_dir, new_dentry);
+	if (ret) {
+		simple_offset_remove(new_ctx, old_dentry);
+		simple_offset_remove(old_ctx, new_dentry);
+		goto out_restore;
+	}
+	return 0;
+
+out_restore:
+	offset_set(old_dentry, old_index);
+	xa_store(&old_ctx->xa, old_index, old_dentry, GFP_KERNEL);
+	offset_set(new_dentry, new_index);
+	xa_store(&new_ctx->xa, new_index, new_dentry, GFP_KERNEL);
+	return ret;
+}
+
+/**
+ * simple_offset_destroy - Release offset map
+ * @octx: directory offset ctx that is about to be destroyed
+ *
+ * During fs teardown (eg. umount), a directory's offset map might still
+ * contain entries. xa_destroy() cleans out anything that remains.
+ */
+void simple_offset_destroy(struct offset_ctx *octx)
+{
+	xa_destroy(&octx->xa);
+}
+
+/**
+ * offset_dir_llseek - Advance the read position of a directory descriptor
+ * @file: an open directory whose position is to be updated
+ * @offset: a byte offset
+ * @whence: enumerator describing the starting position for this update
+ *
+ * SEEK_END, SEEK_DATA, and SEEK_HOLE are not supported for directories.
+ *
+ * Returns the updated read position if successful; otherwise a
+ * negative errno is returned and the read position remains unchanged.
+ */
+static loff_t offset_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	switch (whence) {
+	case SEEK_CUR:
+		offset += file->f_pos;
+		fallthrough;
+	case SEEK_SET:
+		if (offset >= 0)
+			break;
+		fallthrough;
+	default:
+		return -EINVAL;
+	}
+
+	return vfs_setpos(file, offset, U32_MAX);
+}
+
+static struct dentry *offset_find_next(struct xa_state *xas)
+{
+	struct dentry *child, *found = NULL;
+
+	rcu_read_lock();
+	child = xas_next_entry(xas, U32_MAX);
+	if (!child)
+		goto out;
+	spin_lock(&child->d_lock);
+	if (simple_positive(child))
+		found = dget_dlock(child);
+	spin_unlock(&child->d_lock);
+out:
+	rcu_read_unlock();
+	return found;
+}
+
+static bool offset_dir_emit(struct dir_context *ctx, struct dentry *dentry)
+{
+	u32 offset = dentry2offset(dentry);
+	struct inode *inode = d_inode(dentry);
+
+	return ctx->actor(ctx, dentry->d_name.name, dentry->d_name.len, offset,
+			  inode->i_ino, fs_umode_to_dtype(inode->i_mode));
+}
+
+static void offset_iterate_dir(struct inode *inode, struct dir_context *ctx)
+{
+	struct offset_ctx *so_ctx = inode->i_op->get_offset_ctx(inode);
+	XA_STATE(xas, &so_ctx->xa, ctx->pos);
+	struct dentry *dentry;
+
+	while (true) {
+		dentry = offset_find_next(&xas);
+		if (!dentry)
+			break;
+
+		if (!offset_dir_emit(ctx, dentry)) {
+			dput(dentry);
+			break;
+		}
+
+		dput(dentry);
+		ctx->pos = xas.xa_index + 1;
+	}
+}
+
+/**
+ * offset_readdir - Emit entries starting at offset @ctx->pos
+ * @file: an open directory to iterate over
+ * @ctx: directory iteration context
+ *
+ * Caller must hold @file's i_rwsem to prevent insertion or removal of
+ * entries during this call.
+ *
+ * On entry, @ctx->pos contains an offset that represents the first entry
+ * to be read from the directory.
+ *
+ * The operation continues until there are no more entries to read, or
+ * until the ctx->actor indicates there is no more space in the caller's
+ * output buffer.
+ *
+ * On return, @ctx->pos contains an offset that will read the next entry
+ * in this directory when offset_readdir() is called again with @ctx.
+ *
+ * Return values:
+ *   %0 - Complete
+ */
+static int offset_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct dentry *dir = file->f_path.dentry;
+
+	lockdep_assert_held(&d_inode(dir)->i_rwsem);
+
+	if (!dir_emit_dots(file, ctx))
+		return 0;
+
+	offset_iterate_dir(d_inode(dir), ctx);
+	return 0;
+}
+
+const struct file_operations simple_offset_dir_operations = {
+	.llseek		= offset_dir_llseek,
+	.iterate_shared	= offset_readdir,
+	.read		= generic_read_dir,
+	.fsync		= noop_fsync,
+};
+
 static struct dentry *find_next_child(struct dentry *parent, struct dentry *prev)
 {
 	struct dentry *child = NULL;
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index e3e4f4047657..4d826c369da2 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2367,7 +2367,7 @@ int dquot_load_quota_sb(struct super_block *sb, int type, int format_id,
 
 	if (!fmt)
 		return -ESRCH;
-	if (!sb->s_op->quota_write || !sb->s_op->quota_read ||
+	if (!sb->dq_op || !sb->s_qcop ||
 	    (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) {
 		error = -EINVAL;
 		goto out_fmt;
diff --git a/fs/xattr.c b/fs/xattr.c
index e7bbb7f57557..efd4736bc94b 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -1040,12 +1040,32 @@ const char *xattr_full_name(const struct xattr_handler *handler,
 EXPORT_SYMBOL(xattr_full_name);
 
 /**
- * free_simple_xattr - free an xattr object
+ * simple_xattr_space - estimate the memory used by a simple xattr
+ * @name: the full name of the xattr
+ * @size: the size of its value
+ *
+ * This takes no account of how much larger the two slab objects actually are:
+ * that would depend on the slab implementation, when what is required is a
+ * deterministic number, which grows with name length and size and quantity.
+ *
+ * Return: The approximate number of bytes of memory used by such an xattr.
+ */
+size_t simple_xattr_space(const char *name, size_t size)
+{
+	/*
+	 * Use "40" instead of sizeof(struct simple_xattr), to return the
+	 * same result on 32-bit and 64-bit, and even if simple_xattr grows.
+	 */
+	return 40 + size + strlen(name);
+}
+
+/**
+ * simple_xattr_free - free an xattr object
  * @xattr: the xattr object
  *
  * Free the xattr object. Can handle @xattr being NULL.
  */
-static inline void free_simple_xattr(struct simple_xattr *xattr)
+void simple_xattr_free(struct simple_xattr *xattr)
 {
 	if (xattr)
 		kfree(xattr->name);
@@ -1073,7 +1093,7 @@ struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
 	if (len < sizeof(*new_xattr))
 		return NULL;
 
-	new_xattr = kvmalloc(len, GFP_KERNEL);
+	new_xattr = kvmalloc(len, GFP_KERNEL_ACCOUNT);
 	if (!new_xattr)
 		return NULL;
 
@@ -1164,7 +1184,6 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
  * @value: the value to store along the xattr
  * @size: the size of @value
  * @flags: the flags determining how to set the xattr
- * @removed_size: the size of the removed xattr
  *
  * Set a new xattr object.
  * If @value is passed a new xattr object will be allocated. If XATTR_REPLACE
@@ -1181,29 +1200,27 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
  * nothing if XATTR_CREATE is specified in @flags or @flags is zero. For
  * XATTR_REPLACE we fail as mentioned above.
  *
- * Return: On success zero and on error a negative error code is returned.
+ * Return: On success, the removed or replaced xattr is returned, to be freed
+ * by the caller; or NULL if none. On failure a negative error code is returned.
  */
-int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
-		     const void *value, size_t size, int flags,
-		     ssize_t *removed_size)
+struct simple_xattr *simple_xattr_set(struct simple_xattrs *xattrs,
+				      const char *name, const void *value,
+				      size_t size, int flags)
 {
-	struct simple_xattr *xattr = NULL, *new_xattr = NULL;
+	struct simple_xattr *old_xattr = NULL, *new_xattr = NULL;
 	struct rb_node *parent = NULL, **rbp;
 	int err = 0, ret;
 
-	if (removed_size)
-		*removed_size = -1;
-
 	/* value == NULL means remove */
 	if (value) {
 		new_xattr = simple_xattr_alloc(value, size);
 		if (!new_xattr)
-			return -ENOMEM;
+			return ERR_PTR(-ENOMEM);
 
-		new_xattr->name = kstrdup(name, GFP_KERNEL);
+		new_xattr->name = kstrdup(name, GFP_KERNEL_ACCOUNT);
 		if (!new_xattr->name) {
-			free_simple_xattr(new_xattr);
-			return -ENOMEM;
+			simple_xattr_free(new_xattr);
+			return ERR_PTR(-ENOMEM);
 		}
 	}
 
@@ -1217,12 +1234,12 @@ int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 		else if (ret > 0)
 			rbp = &(*rbp)->rb_right;
 		else
-			xattr = rb_entry(*rbp, struct simple_xattr, rb_node);
-		if (xattr)
+			old_xattr = rb_entry(*rbp, struct simple_xattr, rb_node);
+		if (old_xattr)
 			break;
 	}
 
-	if (xattr) {
+	if (old_xattr) {
 		/* Fail if XATTR_CREATE is requested and the xattr exists. */
 		if (flags & XATTR_CREATE) {
 			err = -EEXIST;
@@ -1230,12 +1247,10 @@ int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 		}
 
 		if (new_xattr)
-			rb_replace_node(&xattr->rb_node, &new_xattr->rb_node,
-					&xattrs->rb_root);
+			rb_replace_node(&old_xattr->rb_node,
+					&new_xattr->rb_node, &xattrs->rb_root);
 		else
-			rb_erase(&xattr->rb_node, &xattrs->rb_root);
-		if (!err && removed_size)
-			*removed_size = xattr->size;
+			rb_erase(&old_xattr->rb_node, &xattrs->rb_root);
 	} else {
 		/* Fail if XATTR_REPLACE is requested but no xattr is found. */
 		if (flags & XATTR_REPLACE) {
@@ -1260,12 +1275,10 @@ int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 
 out_unlock:
 	write_unlock(&xattrs->lock);
-	if (err)
-		free_simple_xattr(new_xattr);
-	else
-		free_simple_xattr(xattr);
-	return err;
-
+	if (!err)
+		return old_xattr;
+	simple_xattr_free(new_xattr);
+	return ERR_PTR(err);
 }
 
 static bool xattr_is_trusted(const char *name)
@@ -1370,14 +1383,17 @@ void simple_xattrs_init(struct simple_xattrs *xattrs)
 /**
  * simple_xattrs_free - free xattrs
  * @xattrs: xattr header whose xattrs to destroy
+ * @freed_space: approximate number of bytes of memory freed from @xattrs
  *
  * Destroy all xattrs in @xattr. When this is called no one can hold a
  * reference to any of the xattrs anymore.
  */
-void simple_xattrs_free(struct simple_xattrs *xattrs)
+void simple_xattrs_free(struct simple_xattrs *xattrs, size_t *freed_space)
 {
 	struct rb_node *rbp;
 
+	if (freed_space)
+		*freed_space = 0;
 	rbp = rb_first(&xattrs->rb_root);
 	while (rbp) {
 		struct simple_xattr *xattr;
@@ -1386,7 +1402,10 @@ void simple_xattrs_free(struct simple_xattrs *xattrs)
 		rbp_next = rb_next(rbp);
 		xattr = rb_entry(rbp, struct simple_xattr, rb_node);
 		rb_erase(&xattr->rb_node, &xattrs->rb_root);
-		free_simple_xattr(xattr);
+		if (freed_space)
+			*freed_space += simple_xattr_space(xattr->name,
+							   xattr->size);
+		simple_xattr_free(xattr);
 		rbp = rbp_next;
 	}
 }