xfs: support idmapped mounts
Enable idmapped mounts for xfs. This basically just means passing down
the user_namespace argument from the VFS methods down to where it is
passed to the relevant helpers.
Note that full-filesystem bulkstat is not supported from inside idmapped
mounts as it is an administrative operation that acts on the whole file
system. The limitation is not applied to the bulkstat single operation
that just operates on a single inode.
Link: https://lore.kernel.org/r/20210121131959.646623-40-christian.brauner@ubuntu.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 16ca97a..ca310a1 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -54,10 +54,12 @@ struct xfs_bstat_chunk {
STATIC int
xfs_bulkstat_one_int(
struct xfs_mount *mp,
+ struct user_namespace *mnt_userns,
struct xfs_trans *tp,
xfs_ino_t ino,
struct xfs_bstat_chunk *bc)
{
+ struct user_namespace *sb_userns = mp->m_super->s_user_ns;
struct xfs_icdinode *dic; /* dinode core info pointer */
struct xfs_inode *ip; /* incore inode pointer */
struct inode *inode;
@@ -86,8 +88,8 @@ xfs_bulkstat_one_int(
*/
buf->bs_projectid = ip->i_d.di_projid;
buf->bs_ino = ino;
- buf->bs_uid = i_uid_read(inode);
- buf->bs_gid = i_gid_read(inode);
+ buf->bs_uid = from_kuid(sb_userns, i_uid_into_mnt(mnt_userns, inode));
+ buf->bs_gid = from_kgid(sb_userns, i_gid_into_mnt(mnt_userns, inode));
buf->bs_size = dic->di_size;
buf->bs_nlink = inode->i_nlink;
@@ -173,7 +175,8 @@ xfs_bulkstat_one(
if (!bc.buf)
return -ENOMEM;
- error = xfs_bulkstat_one_int(breq->mp, NULL, breq->startino, &bc);
+ error = xfs_bulkstat_one_int(breq->mp, breq->mnt_userns, NULL,
+ breq->startino, &bc);
kmem_free(bc.buf);
@@ -194,9 +197,10 @@ xfs_bulkstat_iwalk(
xfs_ino_t ino,
void *data)
{
+ struct xfs_bstat_chunk *bc = data;
int error;
- error = xfs_bulkstat_one_int(mp, tp, ino, data);
+ error = xfs_bulkstat_one_int(mp, bc->breq->mnt_userns, tp, ino, data);
/* bulkstat just skips over missing inodes */
if (error == -ENOENT || error == -EINVAL)
return 0;
@@ -239,6 +243,11 @@ xfs_bulkstat(
};
int error;
+ if (breq->mnt_userns != &init_user_ns) {
+ xfs_warn_ratelimited(breq->mp,
+ "bulkstat not supported inside of idmapped mounts.");
+ return -EINVAL;
+ }
if (xfs_bulkstat_already_done(breq->mp, breq->startino))
return 0;