Re: [PATCH v4 11/14] ceph: allow idmapped setattr inode op

From: Xiubo Li
Date: Wed Jun 07 2023 - 22:51:04 EST



On 6/8/23 02:09, Alexander Mikhalitsyn wrote:
From: Christian Brauner <christian.brauner@xxxxxxxxxx>

Enable __ceph_setattr() to handle idmapped mounts. This is just a matter
of passing down the mount's idmapping.

Cc: Xiubo Li <xiubli@xxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
Cc: ceph-devel@xxxxxxxxxxxxxxx
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
[ adapted to b27c82e12965 ("attr: port attribute changes to new types") ]
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
---
v4:
- introduced fsuid/fsgid local variables
v3:
- reworked as Christian suggested here:
https://lore.kernel.org/lkml/20230602-vorzeichen-praktikum-f17931692301@brauner/
---
fs/ceph/inode.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index bcd9b506ec3b..ca438d1353b2 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -2052,31 +2052,35 @@ int __ceph_setattr(struct mnt_idmap *idmap, struct inode *inode,
dout("setattr %p issued %s\n", inode, ceph_cap_string(issued));
if (ia_valid & ATTR_UID) {
+ kuid_t fsuid = from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid);
+
dout("setattr %p uid %d -> %d\n", inode,
from_kuid(&init_user_ns, inode->i_uid),
from_kuid(&init_user_ns, attr->ia_uid));
if (issued & CEPH_CAP_AUTH_EXCL) {
- inode->i_uid = attr->ia_uid;
+ inode->i_uid = fsuid;
dirtied |= CEPH_CAP_AUTH_EXCL;
} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
- !uid_eq(attr->ia_uid, inode->i_uid)) {
+ !uid_eq(fsuid, inode->i_uid)) {
req->r_args.setattr.uid = cpu_to_le32(
- from_kuid(&init_user_ns, attr->ia_uid));
+ from_kuid(&init_user_ns, fsuid));
mask |= CEPH_SETATTR_UID;
release |= CEPH_CAP_AUTH_SHARED;
}
}
if (ia_valid & ATTR_GID) {
+ kgid_t fsgid = from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid);
+
dout("setattr %p gid %d -> %d\n", inode,
from_kgid(&init_user_ns, inode->i_gid),
from_kgid(&init_user_ns, attr->ia_gid));
if (issued & CEPH_CAP_AUTH_EXCL) {
- inode->i_gid = attr->ia_gid;
+ inode->i_gid = fsgid;
dirtied |= CEPH_CAP_AUTH_EXCL;
} else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
- !gid_eq(attr->ia_gid, inode->i_gid)) {
+ !gid_eq(fsgid, inode->i_gid)) {
req->r_args.setattr.gid = cpu_to_le32(
- from_kgid(&init_user_ns, attr->ia_gid));
+ from_kgid(&init_user_ns, fsgid));
mask |= CEPH_SETATTR_GID;
release |= CEPH_CAP_AUTH_SHARED;
}
@@ -2241,7 +2245,7 @@ int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
if (ceph_inode_is_shutdown(inode))
return -ESTALE;
- err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+ err = setattr_prepare(idmap, dentry, attr);
if (err != 0)
return err;
@@ -2256,7 +2260,7 @@ int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
err = __ceph_setattr(idmap, inode, attr);
if (err >= 0 && (attr->ia_valid & ATTR_MODE))
- err = posix_acl_chmod(&nop_mnt_idmap, dentry, attr->ia_mode);
+ err = posix_acl_chmod(idmap, dentry, attr->ia_mode);
return err;
}

You should also do 'req->r_mnt_idmap = idmap;' for sync setattr request.

the setattr will just cache the change locally in client side if the 'x' caps are issued and returns directly or will set a sync setattr reqeust.

Thanks

- Xiubo