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bcachefs: support idmap mounts

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We enable idmapped mounts for bcachefs. Here, we just pass down
the user_namespace argument from the VFS methods to the relevant
helpers.

The idmap test in bcachefs is as following:

```
1. losetup /dev/loop1 bcachefs.img
2. ./bcachefs format /dev/loop1
3. mount -t bcachefs /dev/loop1 /mnt/bcachefs/
4. ./mount-idmapped --map-mount b:0:1000:1 /mnt/bcachefs /mnt/idmapped1/

ll /mnt/bcachefs
total 2
drwx------. 2 root root    0 Jun 14 14:10 lost+found
-rw-r--r--. 1 root root 1945 Jun 14 14:12 profile

ll /mnt/idmapped1/

total 2
drwx------. 2 1000 1000    0 Jun 14 14:10 lost+found
-rw-r--r--. 1 1000 1000 1945 Jun 14 14:12 profile

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Hongbo Li 2024-08-24 09:27:24 +08:00 committed by Kent Overstreet
parent 86e92eeeb2
commit c24adfa0df
1 changed files with 34 additions and 16 deletions
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50
fs/bcachefs/fs.c
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@ -385,6 +385,8 @@ __bch2_create(struct mnt_idmap *idmap,
subvol_inum inum;
struct bch_subvolume subvol;
u64 journal_seq = 0;
kuid_t kuid;
kgid_t kgid;
int ret;
/*
@ -411,13 +413,15 @@ __bch2_create(struct mnt_idmap *idmap,
retry:
bch2_trans_begin(trans);
kuid = mapped_fsuid(idmap, i_user_ns(&dir->v));
kgid = mapped_fsgid(idmap, i_user_ns(&dir->v));
ret = bch2_subvol_is_ro_trans(trans, dir->ei_inum.subvol) ?:
bch2_create_trans(trans,
inode_inum(dir), &dir_u, &inode_u,
!(flags & BCH_CREATE_TMPFILE)
? &dentry->d_name : NULL,
from_kuid(i_user_ns(&dir->v), current_fsuid()),
from_kgid(i_user_ns(&dir->v), current_fsgid()),
from_kuid(i_user_ns(&dir->v), kuid),
from_kgid(i_user_ns(&dir->v), kgid),
mode, rdev,
default_acl, acl, snapshot_src, flags) ?:
bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, 1,
@ -840,11 +844,17 @@ static void bch2_setattr_copy(struct mnt_idmap *idmap,
{
struct bch_fs *c = inode->v.i_sb->s_fs_info;
unsigned int ia_valid = attr->ia_valid;
kuid_t kuid;
kgid_t kgid;
if (ia_valid & ATTR_UID)
bi->bi_uid = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
if (ia_valid & ATTR_GID)
bi->bi_gid = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
if (ia_valid & ATTR_UID) {
kuid = from_vfsuid(idmap, i_user_ns(&inode->v), attr->ia_vfsuid);
bi->bi_uid = from_kuid(i_user_ns(&inode->v), kuid);
}
if (ia_valid & ATTR_GID) {
kgid = from_vfsgid(idmap, i_user_ns(&inode->v), attr->ia_vfsgid);
bi->bi_gid = from_kgid(i_user_ns(&inode->v), kgid);
}
if (ia_valid & ATTR_SIZE)
bi->bi_size = attr->ia_size;
@ -859,11 +869,11 @@ static void bch2_setattr_copy(struct mnt_idmap *idmap,
if (ia_valid & ATTR_MODE) {
umode_t mode = attr->ia_mode;
kgid_t gid = ia_valid & ATTR_GID
? attr->ia_gid
? kgid
: inode->v.i_gid;
if (!in_group_p(gid) &&
!capable_wrt_inode_uidgid(idmap, &inode->v, CAP_FSETID))
if (!in_group_or_capable(idmap, &inode->v,
make_vfsgid(idmap, i_user_ns(&inode->v), gid)))
mode &= ~S_ISGID;
bi->bi_mode = mode;
}
@ -879,17 +889,23 @@ int bch2_setattr_nonsize(struct mnt_idmap *idmap,
struct btree_iter inode_iter = { NULL };
struct bch_inode_unpacked inode_u;
struct posix_acl *acl = NULL;
kuid_t kuid;
kgid_t kgid;
int ret;
mutex_lock(&inode->ei_update_lock);
qid = inode->ei_qid;
if (attr->ia_valid & ATTR_UID)
qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), attr->ia_uid);
if (attr->ia_valid & ATTR_UID) {
kuid = from_vfsuid(idmap, i_user_ns(&inode->v), attr->ia_vfsuid);
qid.q[QTYP_USR] = from_kuid(i_user_ns(&inode->v), kuid);
}
if (attr->ia_valid & ATTR_GID)
qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), attr->ia_gid);
if (attr->ia_valid & ATTR_GID) {
kgid = from_vfsgid(idmap, i_user_ns(&inode->v), attr->ia_vfsgid);
qid.q[QTYP_GRP] = from_kgid(i_user_ns(&inode->v), kgid);
}
ret = bch2_fs_quota_transfer(c, inode, qid, ~0,
KEY_TYPE_QUOTA_PREALLOC);
@ -945,13 +961,15 @@ static int bch2_getattr(struct mnt_idmap *idmap,
{
struct bch_inode_info *inode = to_bch_ei(d_inode(path->dentry));
struct bch_fs *c = inode->v.i_sb->s_fs_info;
vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, &inode->v);
vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, &inode->v);
stat->dev = inode->v.i_sb->s_dev;
stat->ino = inode->v.i_ino;
stat->mode = inode->v.i_mode;
stat->nlink = inode->v.i_nlink;
stat->uid = inode->v.i_uid;
stat->gid = inode->v.i_gid;
stat->uid = vfsuid_into_kuid(vfsuid);
stat->gid = vfsgid_into_kgid(vfsgid);
stat->rdev = inode->v.i_rdev;
stat->size = i_size_read(&inode->v);
stat->atime = inode_get_atime(&inode->v);
@ -2225,7 +2243,7 @@ static struct file_system_type bcache_fs_type = {
.name = "bcachefs",
.init_fs_context = bch2_init_fs_context,
.kill_sb = bch2_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
.fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
};
MODULE_ALIAS_FS("bcachefs");