fs/bcachefs/acl.c - linux - Git at Google


            
            // SPDX-License-Identifier: GPL-2.0


            #include "bcachefs.h"


            #include "acl.h"

            
            #include "xattr.h"


            #include <linux/posix_acl.h>


            static const char * const acl_types[] = {

            
            	[ACL_USER_OBJ]	= "user_obj",

            
            	[ACL_USER]	= "user",

            
            	[ACL_GROUP_OBJ]	= "group_obj",

            
            	[ACL_GROUP]	= "group",

            
            	[ACL_MASK]	= "mask",

            
            	[ACL_OTHER]	= "other",

            
            	NULL,

            
            };


            void bch2_acl_to_text(struct printbuf *out, const void *value, size_t size)

            
            {

            
            	const void *p, *end = value + size;


            	if (!value ||

            
            	    size < sizeof(bch_acl_header) ||

            
            	    ((bch_acl_header *)value)->a_version != cpu_to_le32(BCH_ACL_VERSION))

            
            		return;


            	p = value + sizeof(bch_acl_header);

            
            	while (p < end) {

            
            		const bch_acl_entry *in = p;

            
            		unsigned tag = le16_to_cpu(in->e_tag);


            		prt_str(out, acl_types[tag]);


            		switch (tag) {

            
            		case ACL_USER_OBJ:

            
            		case ACL_GROUP_OBJ:

            
            		case ACL_MASK:

            
            		case ACL_OTHER:

            
            			p += sizeof(bch_acl_entry_short);

            
            			break;

            
            		case ACL_USER:

            
            			prt_printf(out, " uid %u", le32_to_cpu(in->e_id));

            
            			p += sizeof(bch_acl_entry);

            
            			break;

            
            		case ACL_GROUP:

            
            			prt_printf(out, " gid %u", le32_to_cpu(in->e_id));

            
            			p += sizeof(bch_acl_entry);

            
            			break;

            
            		}


            		prt_printf(out, " %o", le16_to_cpu(in->e_perm));


            		if (p != end)

            
            			prt_char(out, ' ');

            
            	}

            
            }


            #ifdef CONFIG_BCACHEFS_POSIX_ACL


            #include "fs.h"


            #include <linux/fs.h>

            
            #include <linux/posix_acl_xattr.h>

            
            #include <linux/sched.h>

            
            #include <linux/slab.h>


            static inline size_t bch2_acl_size(unsigned nr_short, unsigned nr_long)

            
            {

            
            	return sizeof(bch_acl_header) +

            
            		sizeof(bch_acl_entry_short) * nr_short +

            
            		sizeof(bch_acl_entry) * nr_long;

            
            }


            static inline int acl_to_xattr_type(int type)

            
            {

            
            	switch (type) {

            
            	case ACL_TYPE_ACCESS:

            
            		return KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS;

            
            	case ACL_TYPE_DEFAULT:

            
            		return KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT;

            
            	default:

            
            		BUG();

            
            	}

            
            }


            /*

            
             * Convert from filesystem to in-memory representation.

            
             */

            
            static struct posix_acl *bch2_acl_from_disk(struct btree_trans *trans,

            
            					    const void *value, size_t size)

            
            {

            
            	const void *p, *end = value + size;

            
            	struct posix_acl *acl;

            
            	struct posix_acl_entry *out;

            
            	unsigned count = 0;

            
            	int ret;


            	if (!value)

            
            		return NULL;

            
            	if (size < sizeof(bch_acl_header))

            
            		goto invalid;

            
            	if (((bch_acl_header *)value)->a_version !=

            
            	    cpu_to_le32(BCH_ACL_VERSION))

            
            		goto invalid;


            	p = value + sizeof(bch_acl_header);

            
            	while (p < end) {

            
            		const bch_acl_entry *entry = p;


            		if (p + sizeof(bch_acl_entry_short) > end)

            
            			goto invalid;


            		switch (le16_to_cpu(entry->e_tag)) {

            
            		case ACL_USER_OBJ:

            
            		case ACL_GROUP_OBJ:

            
            		case ACL_MASK:

            
            		case ACL_OTHER:

            
            			p += sizeof(bch_acl_entry_short);

            
            			break;

            
            		case ACL_USER:

            
            		case ACL_GROUP:

            
            			p += sizeof(bch_acl_entry);

            
            			break;

            
            		default:

            
            			goto invalid;

            
            		}


            		count++;

            
            	}


            	if (p > end)

            
            		goto invalid;


            	if (!count)

            
            		return NULL;


            	acl = allocate_dropping_locks(trans, ret,

            
            			posix_acl_alloc(count, _gfp));

            
            	if (!acl)

            
            		return ERR_PTR(-ENOMEM);

            
            	if (ret) {

            
            		kfree(acl);

            
            		return ERR_PTR(ret);

            
            	}


            	out = acl->a_entries;


            	p = value + sizeof(bch_acl_header);

            
            	while (p < end) {

            
            		const bch_acl_entry *in = p;


            		out->e_tag  = le16_to_cpu(in->e_tag);

            
            		out->e_perm = le16_to_cpu(in->e_perm);


            		switch (out->e_tag) {

            
            		case ACL_USER_OBJ:

            
            		case ACL_GROUP_OBJ:

            
            		case ACL_MASK:

            
            		case ACL_OTHER:

            
            			p += sizeof(bch_acl_entry_short);

            
            			break;

            
            		case ACL_USER:

            
            			out->e_uid = make_kuid(&init_user_ns,

            
            					       le32_to_cpu(in->e_id));

            
            			p += sizeof(bch_acl_entry);

            
            			break;

            
            		case ACL_GROUP:

            
            			out->e_gid = make_kgid(&init_user_ns,

            
            					       le32_to_cpu(in->e_id));

            
            			p += sizeof(bch_acl_entry);

            
            			break;

            
            		}


            		out++;

            
            	}


            	BUG_ON(out != acl->a_entries + acl->a_count);


            	return acl;

            
            invalid:

            
            	pr_err("invalid acl entry");

            
            	return ERR_PTR(-EINVAL);

            
            }


            #define acl_for_each_entry(acl, acl_e)			\

            
            	for (acl_e = acl->a_entries;			\

            
            	     acl_e < acl->a_entries + acl->a_count;	\

            
            	     acl_e++)


            /*

            
             * Convert from in-memory to filesystem representation.

            
             */

            
            static struct bkey_i_xattr *

            
            bch2_acl_to_xattr(struct btree_trans *trans,

            
            		  const struct posix_acl *acl,

            
            		  int type)

            
            {

            
            	struct bkey_i_xattr *xattr;

            
            	bch_acl_header *acl_header;

            
            	const struct posix_acl_entry *acl_e;

            
            	void *outptr;

            
            	unsigned nr_short = 0, nr_long = 0, acl_len, u64s;


            	acl_for_each_entry(acl, acl_e) {

            
            		switch (acl_e->e_tag) {

            
            		case ACL_USER:

            
            		case ACL_GROUP:

            
            			nr_long++;

            
            			break;

            
            		case ACL_USER_OBJ:

            
            		case ACL_GROUP_OBJ:

            
            		case ACL_MASK:

            
            		case ACL_OTHER:

            
            			nr_short++;

            
            			break;

            
            		default:

            
            			return ERR_PTR(-EINVAL);

            
            		}

            
            	}


            	acl_len = bch2_acl_size(nr_short, nr_long);

            
            	u64s = BKEY_U64s + xattr_val_u64s(0, acl_len);


            	if (u64s > U8_MAX)

            
            		return ERR_PTR(-E2BIG);


            	xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));

            
            	if (IS_ERR(xattr))

            
            		return xattr;


            	bkey_xattr_init(&xattr->k_i);

            
            	xattr->k.u64s		= u64s;

            
            	xattr->v.x_type		= acl_to_xattr_type(type);

            
            	xattr->v.x_name_len	= 0;

            
            	xattr->v.x_val_len	= cpu_to_le16(acl_len);


            	acl_header = xattr_val(&xattr->v);

            
            	acl_header->a_version = cpu_to_le32(BCH_ACL_VERSION);


            	outptr = (void *) acl_header + sizeof(*acl_header);


            	acl_for_each_entry(acl, acl_e) {

            
            		bch_acl_entry *entry = outptr;


            		entry->e_tag = cpu_to_le16(acl_e->e_tag);

            
            		entry->e_perm = cpu_to_le16(acl_e->e_perm);

            
            		switch (acl_e->e_tag) {

            
            		case ACL_USER:

            
            			entry->e_id = cpu_to_le32(

            
            				from_kuid(&init_user_ns, acl_e->e_uid));

            
            			outptr += sizeof(bch_acl_entry);

            
            			break;

            
            		case ACL_GROUP:

            
            			entry->e_id = cpu_to_le32(

            
            				from_kgid(&init_user_ns, acl_e->e_gid));

            
            			outptr += sizeof(bch_acl_entry);

            
            			break;


            		case ACL_USER_OBJ:

            
            		case ACL_GROUP_OBJ:

            
            		case ACL_MASK:

            
            		case ACL_OTHER:

            
            			outptr += sizeof(bch_acl_entry_short);

            
            			break;

            
            		}

            
            	}


            	BUG_ON(outptr != xattr_val(&xattr->v) + acl_len);


            	return xattr;

            
            }


            struct posix_acl *bch2_get_acl(struct inode *vinode, int type, bool rcu)

            
            {

            
            	struct bch_inode_info *inode = to_bch_ei(vinode);

            
            	struct bch_fs *c = inode->v.i_sb->s_fs_info;

            
            	struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);

            
            	struct xattr_search_key search = X_SEARCH(acl_to_xattr_type(type), "", 0);

            
            	struct btree_iter iter = { NULL };

            
            	struct posix_acl *acl = NULL;


            	if (rcu)

            
            		return ERR_PTR(-ECHILD);


            	struct btree_trans *trans = bch2_trans_get(c);

            
            retry:

            
            	bch2_trans_begin(trans);


            	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,

            
            					     &hash, inode_inum(inode), &search, 0);

            
            	int ret = bkey_err(k);

            
            	if (ret)

            
            		goto err;


            	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);

            
            	acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),

            
            				 le16_to_cpu(xattr.v->x_val_len));

            
            	ret = PTR_ERR_OR_ZERO(acl);

            
            err:

            
            	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))

            
            		goto retry;


            	if (ret)

            
            		acl = !bch2_err_matches(ret, ENOENT) ? ERR_PTR(ret) : NULL;


            	if (!IS_ERR_OR_NULL(acl))

            
            		set_cached_acl(&inode->v, type, acl);


            	bch2_trans_iter_exit(trans, &iter);

            
            	bch2_trans_put(trans);

            
            	return acl;

            
            }


            int bch2_set_acl_trans(struct btree_trans *trans, subvol_inum inum,

            
            		       struct bch_inode_unpacked *inode_u,

            
            		       struct posix_acl *acl, int type)

            
            {

            
            	struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode_u);

            
            	int ret;


            	if (type == ACL_TYPE_DEFAULT &&

            
            	    !S_ISDIR(inode_u->bi_mode))

            
            		return acl ? -EACCES : 0;


            	if (acl) {

            
            		struct bkey_i_xattr *xattr =

            
            			bch2_acl_to_xattr(trans, acl, type);

            
            		if (IS_ERR(xattr))

            
            			return PTR_ERR(xattr);


            		ret = bch2_hash_set(trans, bch2_xattr_hash_desc, &hash_info,

            
            				    inum, &xattr->k_i, 0);

            
            	} else {

            
            		struct xattr_search_key search =

            
            			X_SEARCH(acl_to_xattr_type(type), "", 0);


            		ret = bch2_hash_delete(trans, bch2_xattr_hash_desc, &hash_info,

            
            				       inum, &search);

            
            	}


            	return bch2_err_matches(ret, ENOENT) ? 0 : ret;

            
            }


            int bch2_set_acl(struct mnt_idmap *idmap,

            
            		 struct dentry *dentry,

            
            		 struct posix_acl *_acl, int type)

            
            {

            
            	struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);

            
            	struct bch_fs *c = inode->v.i_sb->s_fs_info;

            
            	struct btree_iter inode_iter = { NULL };

            
            	struct bch_inode_unpacked inode_u;

            
            	struct posix_acl *acl;

            
            	umode_t mode;

            
            	int ret;


            	mutex_lock(&inode->ei_update_lock);

            
            	struct btree_trans *trans = bch2_trans_get(c);

            
            retry:

            
            	bch2_trans_begin(trans);

            
            	acl = _acl;


            	ret   = bch2_subvol_is_ro_trans(trans, inode->ei_inum.subvol) ?:

            
            		bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),

            
            			      BTREE_ITER_intent);

            
            	if (ret)

            
            		goto btree_err;


            	mode = inode_u.bi_mode;


            	if (type == ACL_TYPE_ACCESS) {

            
            		ret = posix_acl_update_mode(idmap, &inode->v, &mode, &acl);

            
            		if (ret)

            
            			goto btree_err;

            
            	}


            	ret = bch2_set_acl_trans(trans, inode_inum(inode), &inode_u, acl, type);

            
            	if (ret)

            
            		goto btree_err;


            	inode_u.bi_ctime	= bch2_current_time(c);

            
            	inode_u.bi_mode		= mode;


            	ret =   bch2_inode_write(trans, &inode_iter, &inode_u) ?:

            
            		bch2_trans_commit(trans, NULL, NULL, 0);

            
            btree_err:

            
            	bch2_trans_iter_exit(trans, &inode_iter);


            	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))

            
            		goto retry;

            
            	if (unlikely(ret))

            
            		goto err;


            	bch2_inode_update_after_write(trans, inode, &inode_u,

            
            				      ATTR_CTIME|ATTR_MODE);


            	set_cached_acl(&inode->v, type, acl);

            
            err:

            
            	bch2_trans_put(trans);

            
            	mutex_unlock(&inode->ei_update_lock);


            	return ret;

            
            }


            int bch2_acl_chmod(struct btree_trans *trans, subvol_inum inum,

            
            		   struct bch_inode_unpacked *inode,

            
            		   umode_t mode,

            
            		   struct posix_acl **new_acl)

            
            {

            
            	struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode);

            
            	struct xattr_search_key search = X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0);

            
            	struct btree_iter iter;

            
            	struct posix_acl *acl = NULL;


            	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,

            
            			       &hash_info, inum, &search, BTREE_ITER_intent);

            
            	int ret = bkey_err(k);

            
            	if (ret)

            
            		return bch2_err_matches(ret, ENOENT) ? 0 : ret;


            	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);


            	acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),

            
            			le16_to_cpu(xattr.v->x_val_len));

            
            	ret = PTR_ERR_OR_ZERO(acl);

            
            	if (ret)

            
            		goto err;


            	ret = allocate_dropping_locks_errcode(trans, __posix_acl_chmod(&acl, _gfp, mode));

            
            	if (ret)

            
            		goto err;


            	struct bkey_i_xattr *new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);

            
            	ret = PTR_ERR_OR_ZERO(new);

            
            	if (ret)

            
            		goto err;


            	new->k.p = iter.pos;

            
            	ret = bch2_trans_update(trans, &iter, &new->k_i, 0);

            
            	*new_acl = acl;

            
            	acl = NULL;

            
            err:

            
            	bch2_trans_iter_exit(trans, &iter);

            
            	if (!IS_ERR_OR_NULL(acl))

            
            		kfree(acl);

            
            	return ret;

            
            }


            #endif /* CONFIG_BCACHEFS_POSIX_ACL */
	// SPDX-License-Identifier: GPL-2.0

	#include "bcachefs.h"

	#include "acl.h"
	#include "xattr.h"

	#include <linux/posix_acl.h>

	static const char * const acl_types[] = {
	[ACL_USER_OBJ] = "user_obj",
	[ACL_USER] = "user",
	[ACL_GROUP_OBJ] = "group_obj",
	[ACL_GROUP] = "group",
	[ACL_MASK] = "mask",
	[ACL_OTHER] = "other",
	NULL,
	};

	void bch2_acl_to_text(struct printbuf out, const void value, size_t size)
	{
	const void p, end = value + size;

	if (!value \|\|
	size < sizeof(bch_acl_header) \|\|
	((bch_acl_header *)value)->a_version != cpu_to_le32(BCH_ACL_VERSION))
	return;

	p = value + sizeof(bch_acl_header);
	while (p < end) {
	const bch_acl_entry *in = p;
	unsigned tag = le16_to_cpu(in->e_tag);

	prt_str(out, acl_types[tag]);

	switch (tag) {
	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	p += sizeof(bch_acl_entry_short);
	break;
	case ACL_USER:
	prt_printf(out, " uid %u", le32_to_cpu(in->e_id));
	p += sizeof(bch_acl_entry);
	break;
	case ACL_GROUP:
	prt_printf(out, " gid %u", le32_to_cpu(in->e_id));
	p += sizeof(bch_acl_entry);
	break;
	}

	prt_printf(out, " %o", le16_to_cpu(in->e_perm));

	if (p != end)
	prt_char(out, ' ');
	}
	}

	#ifdef CONFIG_BCACHEFS_POSIX_ACL

	#include "fs.h"

	#include <linux/fs.h>
	#include <linux/posix_acl_xattr.h>
	#include <linux/sched.h>
	#include <linux/slab.h>

	static inline size_t bch2_acl_size(unsigned nr_short, unsigned nr_long)
	{
	return sizeof(bch_acl_header) +
	sizeof(bch_acl_entry_short) * nr_short +
	sizeof(bch_acl_entry) * nr_long;
	}

	static inline int acl_to_xattr_type(int type)
	{
	switch (type) {
	case ACL_TYPE_ACCESS:
	return KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS;
	case ACL_TYPE_DEFAULT:
	return KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT;
	default:
	BUG();
	}
	}

	/*
	* Convert from filesystem to in-memory representation.
	*/
	static struct posix_acl bch2_acl_from_disk(struct btree_trans trans,
	const void *value, size_t size)
	{
	const void p, end = value + size;
	struct posix_acl *acl;
	struct posix_acl_entry *out;
	unsigned count = 0;
	int ret;

	if (!value)
	return NULL;
	if (size < sizeof(bch_acl_header))
	goto invalid;
	if (((bch_acl_header *)value)->a_version !=
	cpu_to_le32(BCH_ACL_VERSION))
	goto invalid;

	p = value + sizeof(bch_acl_header);
	while (p < end) {
	const bch_acl_entry *entry = p;

	if (p + sizeof(bch_acl_entry_short) > end)
	goto invalid;

	switch (le16_to_cpu(entry->e_tag)) {
	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	p += sizeof(bch_acl_entry_short);
	break;
	case ACL_USER:
	case ACL_GROUP:
	p += sizeof(bch_acl_entry);
	break;
	default:
	goto invalid;
	}

	count++;
	}

	if (p > end)
	goto invalid;

	if (!count)
	return NULL;

	acl = allocate_dropping_locks(trans, ret,
	posix_acl_alloc(count, _gfp));
	if (!acl)
	return ERR_PTR(-ENOMEM);
	if (ret) {
	kfree(acl);
	return ERR_PTR(ret);
	}

	out = acl->a_entries;

	p = value + sizeof(bch_acl_header);
	while (p < end) {
	const bch_acl_entry *in = p;

	out->e_tag = le16_to_cpu(in->e_tag);
	out->e_perm = le16_to_cpu(in->e_perm);

	switch (out->e_tag) {
	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	p += sizeof(bch_acl_entry_short);
	break;
	case ACL_USER:
	out->e_uid = make_kuid(&init_user_ns,
	le32_to_cpu(in->e_id));
	p += sizeof(bch_acl_entry);
	break;
	case ACL_GROUP:
	out->e_gid = make_kgid(&init_user_ns,
	le32_to_cpu(in->e_id));
	p += sizeof(bch_acl_entry);
	break;
	}

	out++;
	}

	BUG_ON(out != acl->a_entries + acl->a_count);

	return acl;
	invalid:
	pr_err("invalid acl entry");
	return ERR_PTR(-EINVAL);
	}

	#define acl_for_each_entry(acl, acl_e) \
	for (acl_e = acl->a_entries; \
	acl_e < acl->a_entries + acl->a_count; \
	acl_e++)

	/*
	* Convert from in-memory to filesystem representation.
	*/
	static struct bkey_i_xattr *
	bch2_acl_to_xattr(struct btree_trans *trans,
	const struct posix_acl *acl,
	int type)
	{
	struct bkey_i_xattr *xattr;
	bch_acl_header *acl_header;
	const struct posix_acl_entry *acl_e;
	void *outptr;
	unsigned nr_short = 0, nr_long = 0, acl_len, u64s;

	acl_for_each_entry(acl, acl_e) {
	switch (acl_e->e_tag) {
	case ACL_USER:
	case ACL_GROUP:
	nr_long++;
	break;
	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	nr_short++;
	break;
	default:
	return ERR_PTR(-EINVAL);
	}
	}

	acl_len = bch2_acl_size(nr_short, nr_long);
	u64s = BKEY_U64s + xattr_val_u64s(0, acl_len);

	if (u64s > U8_MAX)
	return ERR_PTR(-E2BIG);

	xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
	if (IS_ERR(xattr))
	return xattr;

	bkey_xattr_init(&xattr->k_i);
	xattr->k.u64s = u64s;
	xattr->v.x_type = acl_to_xattr_type(type);
	xattr->v.x_name_len = 0;
	xattr->v.x_val_len = cpu_to_le16(acl_len);

	acl_header = xattr_val(&xattr->v);
	acl_header->a_version = cpu_to_le32(BCH_ACL_VERSION);

	outptr = (void ) acl_header + sizeof(acl_header);

	acl_for_each_entry(acl, acl_e) {
	bch_acl_entry *entry = outptr;

	entry->e_tag = cpu_to_le16(acl_e->e_tag);
	entry->e_perm = cpu_to_le16(acl_e->e_perm);
	switch (acl_e->e_tag) {
	case ACL_USER:
	entry->e_id = cpu_to_le32(
	from_kuid(&init_user_ns, acl_e->e_uid));
	outptr += sizeof(bch_acl_entry);
	break;
	case ACL_GROUP:
	entry->e_id = cpu_to_le32(
	from_kgid(&init_user_ns, acl_e->e_gid));
	outptr += sizeof(bch_acl_entry);
	break;

	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	outptr += sizeof(bch_acl_entry_short);
	break;
	}
	}

	BUG_ON(outptr != xattr_val(&xattr->v) + acl_len);

	return xattr;
	}

	struct posix_acl bch2_get_acl(struct inode vinode, int type, bool rcu)
	{
	struct bch_inode_info *inode = to_bch_ei(vinode);
	struct bch_fs *c = inode->v.i_sb->s_fs_info;
	struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
	struct xattr_search_key search = X_SEARCH(acl_to_xattr_type(type), "", 0);
	struct btree_iter iter = { NULL };
	struct posix_acl *acl = NULL;

	if (rcu)
	return ERR_PTR(-ECHILD);

	struct btree_trans *trans = bch2_trans_get(c);
	retry:
	bch2_trans_begin(trans);

	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
	&hash, inode_inum(inode), &search, 0);
	int ret = bkey_err(k);
	if (ret)
	goto err;

	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
	acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
	le16_to_cpu(xattr.v->x_val_len));
	ret = PTR_ERR_OR_ZERO(acl);
	err:
	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
	goto retry;

	if (ret)
	acl = !bch2_err_matches(ret, ENOENT) ? ERR_PTR(ret) : NULL;

	if (!IS_ERR_OR_NULL(acl))
	set_cached_acl(&inode->v, type, acl);

	bch2_trans_iter_exit(trans, &iter);
	bch2_trans_put(trans);
	return acl;
	}

	int bch2_set_acl_trans(struct btree_trans *trans, subvol_inum inum,
	struct bch_inode_unpacked *inode_u,
	struct posix_acl *acl, int type)
	{
	struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode_u);
	int ret;

	if (type == ACL_TYPE_DEFAULT &&
	!S_ISDIR(inode_u->bi_mode))
	return acl ? -EACCES : 0;

	if (acl) {
	struct bkey_i_xattr *xattr =
	bch2_acl_to_xattr(trans, acl, type);
	if (IS_ERR(xattr))
	return PTR_ERR(xattr);

	ret = bch2_hash_set(trans, bch2_xattr_hash_desc, &hash_info,
	inum, &xattr->k_i, 0);
	} else {
	struct xattr_search_key search =
	X_SEARCH(acl_to_xattr_type(type), "", 0);

	ret = bch2_hash_delete(trans, bch2_xattr_hash_desc, &hash_info,
	inum, &search);
	}

	return bch2_err_matches(ret, ENOENT) ? 0 : ret;
	}

	int bch2_set_acl(struct mnt_idmap *idmap,
	struct dentry *dentry,
	struct posix_acl *_acl, int type)
	{
	struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
	struct bch_fs *c = inode->v.i_sb->s_fs_info;
	struct btree_iter inode_iter = { NULL };
	struct bch_inode_unpacked inode_u;
	struct posix_acl *acl;
	umode_t mode;
	int ret;

	mutex_lock(&inode->ei_update_lock);
	struct btree_trans *trans = bch2_trans_get(c);
	retry:
	bch2_trans_begin(trans);
	acl = _acl;

	ret = bch2_subvol_is_ro_trans(trans, inode->ei_inum.subvol) ?:
	bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
	BTREE_ITER_intent);
	if (ret)
	goto btree_err;

	mode = inode_u.bi_mode;

	if (type == ACL_TYPE_ACCESS) {
	ret = posix_acl_update_mode(idmap, &inode->v, &mode, &acl);
	if (ret)
	goto btree_err;
	}

	ret = bch2_set_acl_trans(trans, inode_inum(inode), &inode_u, acl, type);
	if (ret)
	goto btree_err;

	inode_u.bi_ctime = bch2_current_time(c);
	inode_u.bi_mode = mode;

	ret = bch2_inode_write(trans, &inode_iter, &inode_u) ?:
	bch2_trans_commit(trans, NULL, NULL, 0);
	btree_err:
	bch2_trans_iter_exit(trans, &inode_iter);

	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
	goto retry;
	if (unlikely(ret))
	goto err;

	bch2_inode_update_after_write(trans, inode, &inode_u,
	ATTR_CTIME\|ATTR_MODE);

	set_cached_acl(&inode->v, type, acl);
	err:
	bch2_trans_put(trans);
	mutex_unlock(&inode->ei_update_lock);

	return ret;
	}

	int bch2_acl_chmod(struct btree_trans *trans, subvol_inum inum,
	struct bch_inode_unpacked *inode,
	umode_t mode,
	struct posix_acl **new_acl)
	{
	struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode);
	struct xattr_search_key search = X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0);
	struct btree_iter iter;
	struct posix_acl *acl = NULL;

	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
	&hash_info, inum, &search, BTREE_ITER_intent);
	int ret = bkey_err(k);
	if (ret)
	return bch2_err_matches(ret, ENOENT) ? 0 : ret;

	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);

	acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
	le16_to_cpu(xattr.v->x_val_len));
	ret = PTR_ERR_OR_ZERO(acl);
	if (ret)
	goto err;

	ret = allocate_dropping_locks_errcode(trans, __posix_acl_chmod(&acl, _gfp, mode));
	if (ret)
	goto err;

	struct bkey_i_xattr *new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
	ret = PTR_ERR_OR_ZERO(new);
	if (ret)
	goto err;

	new->k.p = iter.pos;
	ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
	*new_acl = acl;
	acl = NULL;
	err:
	bch2_trans_iter_exit(trans, &iter);
	if (!IS_ERR_OR_NULL(acl))
	kfree(acl);
	return ret;
	}

	#endif /* CONFIG_BCACHEFS_POSIX_ACL */