1 files changed, 485 insertions, 0 deletions

diff --git a/fs/bcachefs/xattr.c b/fs/bcachefs/xattr.c
new file mode 100644
index 000000000000..f0440d12a031
--- /dev/null
+++ b/fs/bcachefs/xattr.c
@@ -0,0 +1,485 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bkey_methods.h"
+#include "btree_update.h"
+#include "compress.h"
+#include "extents.h"
+#include "fs.h"
+#include "rebalance.h"
+#include "str_hash.h"
+#include "xattr.h"
+
+#include <linux/dcache.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+static const struct xattr_handler *bch2_xattr_type_to_handler(unsigned);
+
+static u64 bch2_xattr_hash(const struct bch_hash_info *info,
+			  const struct xattr_search_key *key)
+{
+	struct bch_str_hash_ctx ctx;
+
+	bch2_str_hash_init(&ctx, info);
+	bch2_str_hash_update(&ctx, info, &key->type, sizeof(key->type));
+	bch2_str_hash_update(&ctx, info, key->name.name, key->name.len);
+
+	return bch2_str_hash_end(&ctx, info);
+}
+
+static u64 xattr_hash_key(const struct bch_hash_info *info, const void *key)
+{
+	return bch2_xattr_hash(info, key);
+}
+
+static u64 xattr_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
+{
+	struct bkey_s_c_xattr x = bkey_s_c_to_xattr(k);
+
+	return bch2_xattr_hash(info,
+		 &X_SEARCH(x.v->x_type, x.v->x_name, x.v->x_name_len));
+}
+
+static bool xattr_cmp_key(struct bkey_s_c _l, const void *_r)
+{
+	struct bkey_s_c_xattr l = bkey_s_c_to_xattr(_l);
+	const struct xattr_search_key *r = _r;
+
+	return l.v->x_type != r->type ||
+		l.v->x_name_len != r->name.len ||
+		memcmp(l.v->x_name, r->name.name, r->name.len);
+}
+
+static bool xattr_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
+{
+	struct bkey_s_c_xattr l = bkey_s_c_to_xattr(_l);
+	struct bkey_s_c_xattr r = bkey_s_c_to_xattr(_r);
+
+	return l.v->x_type != r.v->x_type ||
+		l.v->x_name_len != r.v->x_name_len ||
+		memcmp(l.v->x_name, r.v->x_name, r.v->x_name_len);
+}
+
+const struct bch_hash_desc bch2_xattr_hash_desc = {
+	.btree_id	= BTREE_ID_XATTRS,
+	.key_type	= BCH_XATTR,
+	.whiteout_type	= BCH_XATTR_WHITEOUT,
+	.hash_key	= xattr_hash_key,
+	.hash_bkey	= xattr_hash_bkey,
+	.cmp_key	= xattr_cmp_key,
+	.cmp_bkey	= xattr_cmp_bkey,
+};
+
+const char *bch2_xattr_invalid(const struct bch_fs *c, struct bkey_s_c k)
+{
+	const struct xattr_handler *handler;
+	struct bkey_s_c_xattr xattr;
+
+	switch (k.k->type) {
+	case BCH_XATTR:
+		if (bkey_val_bytes(k.k) < sizeof(struct bch_xattr))
+			return "value too small";
+
+		xattr = bkey_s_c_to_xattr(k);
+
+		if (bkey_val_u64s(k.k) <
+			xattr_val_u64s(xattr.v->x_name_len,
+				       le16_to_cpu(xattr.v->x_val_len)))
+			return "value too small";
+
+		if (bkey_val_u64s(k.k) >
+			xattr_val_u64s(xattr.v->x_name_len,
+				       le16_to_cpu(xattr.v->x_val_len) + 4))
+			return "value too big";
+
+		handler = bch2_xattr_type_to_handler(xattr.v->x_type);
+		if (!handler)
+			return "invalid type";
+
+		if (memchr(xattr.v->x_name, '\0', xattr.v->x_name_len))
+			return "xattr name has invalid characters";
+
+		return NULL;
+	case BCH_XATTR_WHITEOUT:
+		return bkey_val_bytes(k.k) != 0
+			? "value size should be zero"
+			: NULL;
+
+	default:
+		return "invalid type";
+	}
+}
+
+void bch2_xattr_to_text(struct bch_fs *c, char *buf,
+			size_t size, struct bkey_s_c k)
+{
+	const struct xattr_handler *handler;
+	struct bkey_s_c_xattr xattr;
+	size_t n = 0;
+
+	switch (k.k->type) {
+	case BCH_XATTR:
+		xattr = bkey_s_c_to_xattr(k);
+
+		handler = bch2_xattr_type_to_handler(xattr.v->x_type);
+		if (handler && handler->prefix)
+			n += scnprintf(buf + n, size - n, "%s", handler->prefix);
+		else if (handler)
+			n += scnprintf(buf + n, size - n, "(type %u)",
+				       xattr.v->x_type);
+		else
+			n += scnprintf(buf + n, size - n, "(unknown type %u)",
+				       xattr.v->x_type);
+
+		n += bch_scnmemcpy(buf + n, size - n, xattr.v->x_name,
+				   xattr.v->x_name_len);
+		n += scnprintf(buf + n, size - n, ":");
+		n += bch_scnmemcpy(buf + n, size - n, xattr_val(xattr.v),
+				   le16_to_cpu(xattr.v->x_val_len));
+		break;
+	case BCH_XATTR_WHITEOUT:
+		scnprintf(buf, size, "whiteout");
+		break;
+	}
+}
+
+int bch2_xattr_get(struct bch_fs *c, struct bch_inode_info *inode,
+		   const char *name, void *buffer, size_t size, int type)
+{
+	struct btree_trans trans;
+	struct btree_iter *iter;
+	struct bkey_s_c_xattr xattr;
+	int ret;
+
+	bch2_trans_init(&trans, c);
+
+	iter = bch2_hash_lookup(&trans, bch2_xattr_hash_desc,
+				&inode->ei_str_hash, inode->v.i_ino,
+				&X_SEARCH(type, name, strlen(name)),
+				0);
+	if (IS_ERR(iter)) {
+		bch2_trans_exit(&trans);
+		BUG_ON(PTR_ERR(iter) == -EINTR);
+
+		return PTR_ERR(iter) == -ENOENT ? -ENODATA : PTR_ERR(iter);
+	}
+
+	xattr = bkey_s_c_to_xattr(bch2_btree_iter_peek_slot(iter));
+	ret = le16_to_cpu(xattr.v->x_val_len);
+	if (buffer) {
+		if (ret > size)
+			ret = -ERANGE;
+		else
+			memcpy(buffer, xattr_val(xattr.v), ret);
+	}
+
+	bch2_trans_exit(&trans);
+	return ret;
+}
+
+int bch2_xattr_set(struct btree_trans *trans, u64 inum,
+		   const struct bch_hash_info *hash_info,
+		   const char *name, const void *value, size_t size,
+		   int type, int flags)
+{
+	int ret;
+
+	if (value) {
+		struct bkey_i_xattr *xattr;
+		unsigned namelen = strlen(name);
+		unsigned u64s = BKEY_U64s +
+			xattr_val_u64s(namelen, size);
+
+		if (u64s > U8_MAX)
+			return -ERANGE;
+
+		xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
+		if (IS_ERR(xattr))
+			return PTR_ERR(xattr);
+
+		bkey_xattr_init(&xattr->k_i);
+		xattr->k.u64s		= u64s;
+		xattr->v.x_type		= type;
+		xattr->v.x_name_len	= namelen;
+		xattr->v.x_val_len	= cpu_to_le16(size);
+		memcpy(xattr->v.x_name, name, namelen);
+		memcpy(xattr_val(&xattr->v), value, size);
+
+		ret = __bch2_hash_set(trans, bch2_xattr_hash_desc, hash_info,
+			      inum, &xattr->k_i,
+			      (flags & XATTR_CREATE ? BCH_HASH_SET_MUST_CREATE : 0)|
+			      (flags & XATTR_REPLACE ? BCH_HASH_SET_MUST_REPLACE : 0));
+	} else {
+		struct xattr_search_key search =
+			X_SEARCH(type, name, strlen(name));
+
+		ret = bch2_hash_delete(trans, bch2_xattr_hash_desc,
+				       hash_info, inum, &search);
+	}
+
+	if (ret == -ENOENT)
+		ret = flags & XATTR_REPLACE ? -ENODATA : 0;
+
+	return ret;
+}
+
+static size_t bch2_xattr_emit(struct dentry *dentry,
+			     const struct bch_xattr *xattr,
+			     char *buffer, size_t buffer_size)
+{
+	const struct xattr_handler *handler =
+		bch2_xattr_type_to_handler(xattr->x_type);
+
+	if (handler && (!handler->list || handler->list(dentry))) {
+		const char *prefix = handler->prefix ?: handler->name;
+		const size_t prefix_len = strlen(prefix);
+		const size_t total_len = prefix_len + xattr->x_name_len + 1;
+
+		if (buffer && total_len <= buffer_size) {
+			memcpy(buffer, prefix, prefix_len);
+			memcpy(buffer + prefix_len,
+			       xattr->x_name, xattr->x_name_len);
+			buffer[prefix_len + xattr->x_name_len] = '\0';
+		}
+
+		return total_len;
+	} else {
+		return 0;
+	}
+}
+
+ssize_t bch2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	struct bch_fs *c = dentry->d_sb->s_fs_info;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	const struct bch_xattr *xattr;
+	u64 inum = dentry->d_inode->i_ino;
+	ssize_t ret = 0;
+	size_t len;
+
+	for_each_btree_key(&iter, c, BTREE_ID_XATTRS, POS(inum, 0), 0, k) {
+		BUG_ON(k.k->p.inode < inum);
+
+		if (k.k->p.inode > inum)
+			break;
+
+		if (k.k->type != BCH_XATTR)
+			continue;
+
+		xattr = bkey_s_c_to_xattr(k).v;
+
+		len = bch2_xattr_emit(dentry, xattr, buffer, buffer_size);
+		if (buffer) {
+			if (len > buffer_size) {
+				bch2_btree_iter_unlock(&iter);
+				return -ERANGE;
+			}
+
+			buffer += len;
+			buffer_size -= len;
+		}
+
+		ret += len;
+
+	}
+	bch2_btree_iter_unlock(&iter);
+
+	return ret;
+}
+
+static int bch2_xattr_get_handler(const struct xattr_handler *handler,
+				  struct dentry *dentry, struct inode *vinode,
+				  const char *name, void *buffer, size_t size)
+{
+	struct bch_inode_info *inode = to_bch_ei(vinode);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+
+	return bch2_xattr_get(c, inode, name, buffer, size, handler->flags);
+}
+
+static int bch2_xattr_set_handler(const struct xattr_handler *handler,
+				  struct mnt_idmap *idmap,
+				  struct dentry *dentry, struct inode *vinode,
+				  const char *name, const void *value,
+				  size_t size, int flags)
+{
+	struct bch_inode_info *inode = to_bch_ei(vinode);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+
+	return bch2_trans_do(c, &inode->ei_journal_seq, BTREE_INSERT_ATOMIC,
+			bch2_xattr_set(&trans, inode->v.i_ino,
+				       &inode->ei_str_hash,
+				       name, value, size,
+				       handler->flags, flags));
+}
+
+static const struct xattr_handler bch_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.get	= bch2_xattr_get_handler,
+	.set	= bch2_xattr_set_handler,
+	.flags	= BCH_XATTR_INDEX_USER,
+};
+
+static bool bch2_xattr_trusted_list(struct dentry *dentry)
+{
+	return capable(CAP_SYS_ADMIN);
+}
+
+static const struct xattr_handler bch_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.list	= bch2_xattr_trusted_list,
+	.get	= bch2_xattr_get_handler,
+	.set	= bch2_xattr_set_handler,
+	.flags	= BCH_XATTR_INDEX_TRUSTED,
+};
+
+static const struct xattr_handler bch_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.get	= bch2_xattr_get_handler,
+	.set	= bch2_xattr_set_handler,
+	.flags	= BCH_XATTR_INDEX_SECURITY,
+};
+
+#ifndef NO_BCACHEFS_FS
+
+static int bch2_xattr_bcachefs_get(const struct xattr_handler *handler,
+				   struct dentry *dentry, struct inode *vinode,
+				   const char *name, void *buffer, size_t size)
+{
+	struct bch_inode_info *inode = to_bch_ei(vinode);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	struct bch_opts opts =
+		bch2_inode_opts_to_opts(bch2_inode_opts_get(&inode->ei_inode));
+	const struct bch_option *opt;
+	int ret, id;
+	u64 v;
+
+	id = bch2_opt_lookup(name);
+	if (id < 0 || !bch2_opt_is_inode_opt(id))
+		return -EINVAL;
+
+	opt = bch2_opt_table + id;
+
+	if (!bch2_opt_defined_by_id(&opts, id))
+		return -ENODATA;
+
+	v = bch2_opt_get_by_id(&opts, id);
+
+	ret = bch2_opt_to_text(c, buffer, size, opt, v, 0);
+
+	return ret < size || !buffer ? ret : -ERANGE;
+}
+
+struct inode_opt_set {
+	int			id;
+	u64			v;
+	bool			defined;
+};
+
+static int inode_opt_set_fn(struct bch_inode_info *inode,
+			    struct bch_inode_unpacked *bi,
+			    void *p)
+{
+	struct inode_opt_set *s = p;
+
+	if (s->defined)
+		bch2_inode_opt_set(bi, s->id, s->v);
+	else
+		bch2_inode_opt_clear(bi, s->id);
+	return 0;
+}
+
+static int bch2_xattr_bcachefs_set(const struct xattr_handler *handler,
+				   struct mnt_idmap *idmap,
+				   struct dentry *dentry, struct inode *vinode,
+				   const char *name, const void *value,
+				   size_t size, int flags)
+{
+	struct bch_inode_info *inode = to_bch_ei(vinode);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	const struct bch_option *opt;
+	char *buf;
+	struct inode_opt_set s;
+	int ret;
+
+	s.id = bch2_opt_lookup(name);
+	if (s.id < 0 || !bch2_opt_is_inode_opt(s.id))
+		return -EINVAL;
+
+	opt = bch2_opt_table + s.id;
+
+	if (value) {
+		buf = kmalloc(size + 1, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+		memcpy(buf, value, size);
+		buf[size] = '\0';
+
+		ret = bch2_opt_parse(c, opt, buf, &s.v);
+		kfree(buf);
+
+		if (ret < 0)
+			return ret;
+
+		if (s.id == Opt_compression ||
+		    s.id == Opt_background_compression) {
+			ret = bch2_check_set_has_compressed_data(c, s.v);
+			if (ret)
+				return ret;
+		}
+
+		s.defined = true;
+	} else {
+		s.defined = false;
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	ret = __bch2_write_inode(c, inode, inode_opt_set_fn, &s, 0);
+	mutex_unlock(&inode->ei_update_lock);
+
+	if (value &&
+	    (s.id == Opt_background_compression ||
+	     s.id == Opt_background_target))
+		bch2_rebalance_add_work(c, inode->v.i_blocks);
+
+	return ret;
+}
+
+static const struct xattr_handler bch_xattr_bcachefs_handler = {
+	.prefix	= "bcachefs.",
+	.get	= bch2_xattr_bcachefs_get,
+	.set	= bch2_xattr_bcachefs_set,
+};
+
+#endif /* NO_BCACHEFS_FS */
+
+const struct xattr_handler *bch2_xattr_handlers[] = {
+	&bch_xattr_user_handler,
+	&nop_posix_acl_access,
+	&nop_posix_acl_default,
+	&bch_xattr_trusted_handler,
+	&bch_xattr_security_handler,
+#ifndef NO_BCACHEFS_FS
+	&bch_xattr_bcachefs_handler,
+#endif
+	NULL
+};
+
+static const struct xattr_handler *bch_xattr_handler_map[] = {
+	[BCH_XATTR_INDEX_USER]			= &bch_xattr_user_handler,
+	[BCH_XATTR_INDEX_POSIX_ACL_ACCESS]	=
+		&nop_posix_acl_access,
+	[BCH_XATTR_INDEX_POSIX_ACL_DEFAULT]	=
+		&nop_posix_acl_default,
+	[BCH_XATTR_INDEX_TRUSTED]		= &bch_xattr_trusted_handler,
+	[BCH_XATTR_INDEX_SECURITY]		= &bch_xattr_security_handler,
+};
+
+static const struct xattr_handler *bch2_xattr_type_to_handler(unsigned type)
+{
+	return type < ARRAY_SIZE(bch_xattr_handler_map)
+		? bch_xattr_handler_map[type]
+		: NULL;
+}