[ Upstream commit
2878dffc7db0b5a51e308ccb6b571296b57c82e7 ]
When copying inode attributes from the upper or lower layer to ovl inodes
we need to take the upper or lower layer's mount's idmapping into
account. In a lot of places we call ovl_copyattr() only on upper inodes and
in some we call it on either upper or lower inodes. Split this into two
separate helpers.
The first one should only be called on upper
inodes and is thus called ovl_copy_upperattr(). The second one can be
called on upper or lower inodes. We add ovl_copy_realattr() for this
task. The new helper makes use of the previously added ovl_i_path_real()
helper. This is needed to support idmapped base layers with overlay.
When overlay copies the inode information from an upper or lower layer
to the relevant overlay inode it will apply the idmapping of the upper
or lower layer when doing so. The ovl inode ownership will thus always
correctly reflect the ownership of the idmapped upper or lower layer.
All idmapping helpers are nops when no idmapped base layers are used.
Cc: <linux-unionfs@vger.kernel.org>
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of:
b306e90ffabd ("ovl: remove privs in ovl_copyfile()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
{
int err;
const struct cred *old_cred;
- struct dentry *upperdentry;
bool lower_positive = ovl_lower_positive(dentry);
LIST_HEAD(list);
* Note: we fail to update ctime if there was no copy-up, only a
* whiteout
*/
- upperdentry = ovl_dentry_upper(dentry);
- if (upperdentry)
- ovl_copyattr(d_inode(upperdentry), d_inode(dentry));
+ if (ovl_dentry_upper(dentry))
+ ovl_copyattr(d_inode(dentry));
out_drop_write:
ovl_drop_write(dentry);
(d_inode(new) && ovl_type_origin(new)));
/* copy ctime: */
- ovl_copyattr(d_inode(olddentry), d_inode(old));
+ ovl_copyattr(d_inode(old));
if (d_inode(new) && ovl_dentry_upper(new))
- ovl_copyattr(d_inode(newdentry), d_inode(new));
+ ovl_copyattr(d_inode(new));
out_dput:
dput(newdentry);
__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
SB_FREEZE_WRITE);
file_end_write(iocb->ki_filp);
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
}
orig_iocb->ki_pos = iocb->ki_pos;
inode_lock(inode);
/* Update mode */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
ret = file_remove_privs(file);
if (ret)
goto out_unlock;
ovl_iocb_to_rwf(ifl));
file_end_write(real.file);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
} else {
struct ovl_aio_req *aio_req;
struct fd real;
const struct cred *old_cred;
struct inode *inode = file_inode(out);
- struct inode *realinode = ovl_inode_real(inode);
ssize_t ret;
inode_lock(inode);
/* Update mode */
- ovl_copyattr(realinode, inode);
+ ovl_copyattr(inode);
ret = file_remove_privs(out);
if (ret)
goto out_unlock;
file_end_write(real.file);
/* Update size */
- ovl_copyattr(realinode, inode);
+ ovl_copyattr(inode);
revert_creds(old_cred);
fdput(real);
revert_creds(old_cred);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
fdput(real);
revert_creds(old_cred);
/* Update size */
- ovl_copyattr(ovl_inode_real(inode_out), inode_out);
+ ovl_copyattr(inode_out);
fdput(real_in);
fdput(real_out);
err = notify_change(&init_user_ns, upperdentry, attr, NULL);
revert_creds(old_cred);
if (!err)
- ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
+ ovl_copyattr(dentry->d_inode);
inode_unlock(upperdentry->d_inode);
if (winode)
revert_creds(old_cred);
/* copy c/mtime */
- ovl_copyattr(d_inode(realdentry), inode);
+ ovl_copyattr(inode);
out_drop_write:
ovl_drop_write(dentry);
inode_set_flags(inode, flags, OVL_COPY_I_FLAGS_MASK);
/* Update ctime */
- ovl_copyattr(ovl_inode_real(inode), inode);
+ ovl_copyattr(inode);
}
ovl_drop_write(dentry);
out:
oi->lowerdata = igrab(d_inode(oip->lowerdata));
realinode = ovl_inode_real(inode);
- ovl_copyattr(realinode, inode);
+ ovl_copyattr(inode);
ovl_copyflags(realinode, inode);
ovl_map_ino(inode, ino, fsid);
}
struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
struct inode *ovl_get_inode(struct super_block *sb,
struct ovl_inode_params *oip);
-static inline void ovl_copyattr(struct inode *from, struct inode *to)
-{
- to->i_uid = from->i_uid;
- to->i_gid = from->i_gid;
- to->i_mode = from->i_mode;
- to->i_atime = from->i_atime;
- to->i_mtime = from->i_mtime;
- to->i_ctime = from->i_ctime;
- i_size_write(to, i_size_read(from));
-}
+void ovl_copyattr(struct inode *to);
/* vfs inode flags copied from real to ovl inode */
#define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
void ovl_dir_modified(struct dentry *dentry, bool impurity)
{
/* Copy mtime/ctime */
- ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
+ ovl_copyattr(d_inode(dentry));
ovl_dir_version_inc(dentry, impurity);
}
return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
}
+
+/*
+ * ovl_copyattr() - copy inode attributes from layer to ovl inode
+ *
+ * When overlay copies inode information from an upper or lower layer to the
+ * relevant overlay inode it will apply the idmapping of the upper or lower
+ * layer when doing so ensuring that the ovl inode ownership will correctly
+ * reflect the ownership of the idmapped upper or lower layer. For example, an
+ * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to
+ * map any lower or upper inode owned by id 1001 to id 1000. These mapping
+ * helpers are nops when the relevant layer isn't idmapped.
+ */
+void ovl_copyattr(struct inode *inode)
+{
+ struct path realpath;
+ struct inode *realinode;
+ struct user_namespace *real_mnt_userns;
+
+ ovl_i_path_real(inode, &realpath);
+ realinode = d_inode(realpath.dentry);
+ real_mnt_userns = mnt_user_ns(realpath.mnt);
+
+ inode->i_uid = i_uid_into_mnt(real_mnt_userns, realinode);
+ inode->i_gid = i_gid_into_mnt(real_mnt_userns, realinode);
+ inode->i_mode = realinode->i_mode;
+ inode->i_atime = realinode->i_atime;
+ inode->i_mtime = realinode->i_mtime;
+ inode->i_ctime = realinode->i_ctime;
+ i_size_write(inode, i_size_read(realinode));
+}