linux/fs/bcachefs/xattr.c
Kent Overstreet 548e7f5167 bcachefs: setting bcachefs_effective.* xattrs is a noop
bcachefs_effective.* xattrs show the options inherited from parent
directories (as well as explicitly set); this namespace is not for
setting bcachefs options.

Change the .set() handler to a noop so that if e.g. rsync is copying
xattrs it'll do the right thing, and only copy xattrs in the bcachefs.*
namespace. We don't want to return an error, because that will cause
rsync to bail out or get spammy.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-08-22 02:07:22 -04:00

664 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "acl.h"
#include "bkey_methods.h"
#include "btree_update.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 = KEY_TYPE_xattr,
.hash_key = xattr_hash_key,
.hash_bkey = xattr_hash_bkey,
.cmp_key = xattr_cmp_key,
.cmp_bkey = xattr_cmp_bkey,
};
int bch2_xattr_validate(struct bch_fs *c, struct bkey_s_c k,
enum bch_validate_flags flags)
{
struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
unsigned val_u64s = xattr_val_u64s(xattr.v->x_name_len,
le16_to_cpu(xattr.v->x_val_len));
int ret = 0;
bkey_fsck_err_on(bkey_val_u64s(k.k) < val_u64s,
c, xattr_val_size_too_small,
"value too small (%zu < %u)",
bkey_val_u64s(k.k), val_u64s);
/* XXX why +4 ? */
val_u64s = xattr_val_u64s(xattr.v->x_name_len,
le16_to_cpu(xattr.v->x_val_len) + 4);
bkey_fsck_err_on(bkey_val_u64s(k.k) > val_u64s,
c, xattr_val_size_too_big,
"value too big (%zu > %u)",
bkey_val_u64s(k.k), val_u64s);
bkey_fsck_err_on(!bch2_xattr_type_to_handler(xattr.v->x_type),
c, xattr_invalid_type,
"invalid type (%u)", xattr.v->x_type);
bkey_fsck_err_on(memchr(xattr.v->x_name, '\0', xattr.v->x_name_len),
c, xattr_name_invalid_chars,
"xattr name has invalid characters");
fsck_err:
return ret;
}
void bch2_xattr_to_text(struct printbuf *out, struct bch_fs *c,
struct bkey_s_c k)
{
const struct xattr_handler *handler;
struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
handler = bch2_xattr_type_to_handler(xattr.v->x_type);
if (handler && handler->prefix)
prt_printf(out, "%s", handler->prefix);
else if (handler)
prt_printf(out, "(type %u)", xattr.v->x_type);
else
prt_printf(out, "(unknown type %u)", xattr.v->x_type);
unsigned name_len = xattr.v->x_name_len;
unsigned val_len = le16_to_cpu(xattr.v->x_val_len);
unsigned max_name_val_bytes = bkey_val_bytes(xattr.k) -
offsetof(struct bch_xattr, x_name);
val_len = min_t(int, val_len, max_name_val_bytes - name_len);
name_len = min(name_len, max_name_val_bytes);
prt_printf(out, "%.*s:%.*s",
name_len, xattr.v->x_name,
val_len, (char *) xattr_val(xattr.v));
if (xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS ||
xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT) {
prt_char(out, ' ');
bch2_acl_to_text(out, xattr_val(xattr.v),
le16_to_cpu(xattr.v->x_val_len));
}
}
static int bch2_xattr_get_trans(struct btree_trans *trans, struct bch_inode_info *inode,
const char *name, void *buffer, size_t size, int type)
{
struct bch_hash_info hash = bch2_hash_info_init(trans->c, &inode->ei_inode);
struct xattr_search_key search = X_SEARCH(type, name, strlen(name));
struct btree_iter iter;
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)
return ret;
struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
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_iter_exit(trans, &iter);
return ret;
}
int bch2_xattr_set(struct btree_trans *trans, subvol_inum inum,
struct bch_inode_unpacked *inode_u,
const struct bch_hash_info *hash_info,
const char *name, const void *value, size_t size,
int type, int flags)
{
struct bch_fs *c = trans->c;
struct btree_iter inode_iter = { NULL };
int ret;
ret = bch2_subvol_is_ro_trans(trans, inum.subvol) ?:
bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent);
if (ret)
return ret;
inode_u->bi_ctime = bch2_current_time(c);
ret = bch2_inode_write(trans, &inode_iter, inode_u);
bch2_trans_iter_exit(trans, &inode_iter);
if (ret)
return 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 ? STR_HASH_must_create : 0)|
(flags & XATTR_REPLACE ? STR_HASH_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 (bch2_err_matches(ret, ENOENT))
ret = flags & XATTR_REPLACE ? -ENODATA : 0;
return ret;
}
struct xattr_buf {
char *buf;
size_t len;
size_t used;
};
static int __bch2_xattr_emit(const char *prefix,
const char *name, size_t name_len,
struct xattr_buf *buf)
{
const size_t prefix_len = strlen(prefix);
const size_t total_len = prefix_len + name_len + 1;
if (buf->buf) {
if (buf->used + total_len > buf->len)
return -ERANGE;
memcpy(buf->buf + buf->used, prefix, prefix_len);
memcpy(buf->buf + buf->used + prefix_len,
name, name_len);
buf->buf[buf->used + prefix_len + name_len] = '\0';
}
buf->used += total_len;
return 0;
}
static int bch2_xattr_emit(struct dentry *dentry,
const struct bch_xattr *xattr,
struct xattr_buf *buf)
{
const struct xattr_handler *handler =
bch2_xattr_type_to_handler(xattr->x_type);
return handler && (!handler->list || handler->list(dentry))
? __bch2_xattr_emit(handler->prefix ?: handler->name,
xattr->x_name, xattr->x_name_len, buf)
: 0;
}
static int bch2_xattr_list_bcachefs(struct bch_fs *c,
struct bch_inode_unpacked *inode,
struct xattr_buf *buf,
bool all)
{
const char *prefix = all ? "bcachefs_effective." : "bcachefs.";
unsigned id;
int ret = 0;
u64 v;
for (id = 0; id < Inode_opt_nr; id++) {
v = bch2_inode_opt_get(inode, id);
if (!v)
continue;
if (!all &&
!(inode->bi_fields_set & (1 << id)))
continue;
ret = __bch2_xattr_emit(prefix, bch2_inode_opts[id],
strlen(bch2_inode_opts[id]), buf);
if (ret)
break;
}
return ret;
}
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 bch_inode_info *inode = to_bch_ei(dentry->d_inode);
struct btree_trans *trans = bch2_trans_get(c);
struct btree_iter iter;
struct bkey_s_c k;
struct xattr_buf buf = { .buf = buffer, .len = buffer_size };
u64 offset = 0, inum = inode->ei_inode.bi_inum;
u32 snapshot;
int ret;
retry:
bch2_trans_begin(trans);
iter = (struct btree_iter) { NULL };
ret = bch2_subvolume_get_snapshot(trans, inode->ei_subvol, &snapshot);
if (ret)
goto err;
for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_xattrs,
SPOS(inum, offset, snapshot),
POS(inum, U64_MAX), 0, k, ret) {
if (k.k->type != KEY_TYPE_xattr)
continue;
ret = bch2_xattr_emit(dentry, bkey_s_c_to_xattr(k).v, &buf);
if (ret)
break;
}
offset = iter.pos.offset;
bch2_trans_iter_exit(trans, &iter);
err:
if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
goto retry;
bch2_trans_put(trans);
if (ret)
goto out;
ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, false);
if (ret)
goto out;
ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, true);
if (ret)
goto out;
return buf.used;
out:
return bch2_err_class(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;
int ret = bch2_trans_do(c, NULL, NULL, 0,
bch2_xattr_get_trans(trans, inode, name, buffer, size, handler->flags));
if (ret < 0 && bch2_err_matches(ret, ENOENT))
ret = -ENODATA;
return bch2_err_class(ret);
}
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;
struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
struct bch_inode_unpacked inode_u;
int ret;
ret = bch2_trans_run(c,
commit_do(trans, NULL, NULL, 0,
bch2_xattr_set(trans, inode_inum(inode), &inode_u,
&hash, name, value, size,
handler->flags, flags)) ?:
(bch2_inode_update_after_write(trans, inode, &inode_u, ATTR_CTIME), 0));
return bch2_err_class(ret);
}
static const struct xattr_handler bch_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.get = bch2_xattr_get_handler,
.set = bch2_xattr_set_handler,
.flags = KEY_TYPE_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 = KEY_TYPE_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 = KEY_TYPE_XATTR_INDEX_SECURITY,
};
#ifndef NO_BCACHEFS_FS
static int opt_to_inode_opt(int id)
{
switch (id) {
#define x(name, ...) \
case Opt_##name: return Inode_opt_##name;
BCH_INODE_OPTS()
#undef x
default:
return -1;
}
}
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,
bool all)
{
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(&inode->ei_inode);
const struct bch_option *opt;
int id, inode_opt_id;
struct printbuf out = PRINTBUF;
int ret;
u64 v;
id = bch2_opt_lookup(name);
if (id < 0 || !bch2_opt_is_inode_opt(id))
return -EINVAL;
inode_opt_id = opt_to_inode_opt(id);
if (inode_opt_id < 0)
return -EINVAL;
opt = bch2_opt_table + id;
if (!bch2_opt_defined_by_id(&opts, id))
return -ENODATA;
if (!all &&
!(inode->ei_inode.bi_fields_set & (1 << inode_opt_id)))
return -ENODATA;
v = bch2_opt_get_by_id(&opts, id);
bch2_opt_to_text(&out, c, c->disk_sb.sb, opt, v, 0);
ret = out.pos;
if (out.allocation_failure) {
ret = -ENOMEM;
} else if (buffer) {
if (out.pos > size)
ret = -ERANGE;
else
memcpy(buffer, out.buf, out.pos);
}
printbuf_exit(&out);
return ret;
}
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)
{
return __bch2_xattr_bcachefs_get(handler, dentry, vinode,
name, buffer, size, false);
}
struct inode_opt_set {
int id;
u64 v;
bool defined;
};
static int inode_opt_set_fn(struct btree_trans *trans,
struct bch_inode_info *inode,
struct bch_inode_unpacked *bi,
void *p)
{
struct inode_opt_set *s = p;
if (s->defined)
bi->bi_fields_set |= 1U << s->id;
else
bi->bi_fields_set &= ~(1U << s->id);
bch2_inode_opt_set(bi, s->id, s->v);
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 opt_id, inode_opt_id, ret;
opt_id = bch2_opt_lookup(name);
if (opt_id < 0)
return -EINVAL;
opt = bch2_opt_table + opt_id;
inode_opt_id = opt_to_inode_opt(opt_id);
if (inode_opt_id < 0)
return -EINVAL;
s.id = inode_opt_id;
if (value) {
u64 v = 0;
buf = kmalloc(size + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
memcpy(buf, value, size);
buf[size] = '\0';
ret = bch2_opt_parse(c, opt, buf, &v, NULL);
kfree(buf);
if (ret < 0)
goto err_class_exit;
ret = bch2_opt_check_may_set(c, opt_id, v);
if (ret < 0)
goto err_class_exit;
s.v = v + 1;
s.defined = true;
} else {
/*
* Check if this option was set on the parent - if so, switched
* back to inheriting from the parent:
*
* rename() also has to deal with keeping inherited options up
* to date - see bch2_reinherit_attrs()
*/
spin_lock(&dentry->d_lock);
if (!IS_ROOT(dentry)) {
struct bch_inode_info *dir =
to_bch_ei(d_inode(dentry->d_parent));
s.v = bch2_inode_opt_get(&dir->ei_inode, inode_opt_id);
} else {
s.v = 0;
}
spin_unlock(&dentry->d_lock);
s.defined = false;
}
mutex_lock(&inode->ei_update_lock);
if (inode_opt_id == Inode_opt_project) {
/*
* inode fields accessible via the xattr interface are stored
* with a +1 bias, so that 0 means unset:
*/
ret = bch2_set_projid(c, inode, s.v ? s.v - 1 : 0);
if (ret)
goto err;
}
ret = bch2_write_inode(c, inode, inode_opt_set_fn, &s, 0);
err:
mutex_unlock(&inode->ei_update_lock);
if (value &&
(opt_id == Opt_background_target ||
opt_id == Opt_background_compression ||
(opt_id == Opt_compression && !inode_opt_get(c, &inode->ei_inode, background_compression))))
bch2_set_rebalance_needs_scan(c, inode->ei_inode.bi_inum);
err_class_exit:
return bch2_err_class(ret);
}
static const struct xattr_handler bch_xattr_bcachefs_handler = {
.prefix = "bcachefs.",
.get = bch2_xattr_bcachefs_get,
.set = bch2_xattr_bcachefs_set,
};
static int bch2_xattr_bcachefs_get_effective(
const struct xattr_handler *handler,
struct dentry *dentry, struct inode *vinode,
const char *name, void *buffer, size_t size)
{
return __bch2_xattr_bcachefs_get(handler, dentry, vinode,
name, buffer, size, true);
}
/* Noop - xattrs in the bcachefs_effective namespace are inherited */
static int bch2_xattr_bcachefs_set_effective(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)
{
return 0;
}
static const struct xattr_handler bch_xattr_bcachefs_effective_handler = {
.prefix = "bcachefs_effective.",
.get = bch2_xattr_bcachefs_get_effective,
.set = bch2_xattr_bcachefs_set_effective,
};
#endif /* NO_BCACHEFS_FS */
const struct xattr_handler *bch2_xattr_handlers[] = {
&bch_xattr_user_handler,
#ifdef CONFIG_BCACHEFS_POSIX_ACL
&nop_posix_acl_access,
&nop_posix_acl_default,
#endif
&bch_xattr_trusted_handler,
&bch_xattr_security_handler,
#ifndef NO_BCACHEFS_FS
&bch_xattr_bcachefs_handler,
&bch_xattr_bcachefs_effective_handler,
#endif
NULL
};
static const struct xattr_handler *bch_xattr_handler_map[] = {
[KEY_TYPE_XATTR_INDEX_USER] = &bch_xattr_user_handler,
[KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS] =
&nop_posix_acl_access,
[KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT] =
&nop_posix_acl_default,
[KEY_TYPE_XATTR_INDEX_TRUSTED] = &bch_xattr_trusted_handler,
[KEY_TYPE_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;
}