diff options
| author |   Darrick J. Wong <djwong@kernel.org> | 2024-11-03 20:18:53 -0800 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2024-11-05 13:38:32 -0800 |
| commit | bb6cdd5529ff67081466ef7257000b04204aea23 (patch) | |
| tree | da8ef2cd20d53cd837b2260b3cd6088b78c91469 | |
| parent | xfs: disable the agi rotor for metadata inodes (diff) | |
| download | wireguard-linux-bb6cdd5529ff67081466ef7257000b04204aea23.tar.xz wireguard-linux-bb6cdd5529ff67081466ef7257000b04204aea23.zip | |
xfs: hide metadata inodes from everyone because they are special
Metadata inodes are private files and therefore cannot be exposed to
userspace. This means no bulkstat, no open-by-handle, no linking them
into the directory tree, and no feeding them to LSMs. As such, we mark
them S_PRIVATE, which stops all that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | fs/xfs/scrub/tempfile.c | 8 | ||||
| -rw-r--r-- | fs/xfs/xfs_iops.c | 15 |
2 files changed, 22 insertions, 1 deletions
diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c index 177f922acfaf..3c5a1d77fefa 100644 --- a/fs/xfs/scrub/tempfile.c +++ b/fs/xfs/scrub/tempfile.c @@ -844,6 +844,14 @@ xrep_is_tempfile( const struct xfs_inode *ip) { const struct inode *inode = &ip->i_vnode; + struct xfs_mount *mp = ip->i_mount; + + /* + * Files in the metadata directory tree also have S_PRIVATE set and + * IOP_XATTR unset, so we must distinguish them separately. + */ + if (xfs_has_metadir(mp) && (ip->i_diflags2 & XFS_DIFLAG2_METADATA)) + return false; if (IS_PRIVATE(inode) && !(inode->i_opflags & IOP_XATTR)) return true; diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index ee79cf161312..66a726a5fbbb 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -42,7 +42,9 @@ * held. For regular files, the lock order is the other way around - the * mmap_lock is taken during the page fault, and then we lock the ilock to do * block mapping. Hence we need a different class for the directory ilock so - * that lockdep can tell them apart. + * that lockdep can tell them apart. Directories in the metadata directory + * tree get a separate class so that lockdep reports will warn us if someone + * ever tries to lock regular directories after locking metadata directories. */ static struct lock_class_key xfs_nondir_ilock_class; static struct lock_class_key xfs_dir_ilock_class; @@ -1289,6 +1291,7 @@ xfs_setup_inode( { struct inode *inode = &ip->i_vnode; gfp_t gfp_mask; + bool is_meta = xfs_is_internal_inode(ip); inode->i_ino = ip->i_ino; inode->i_state |= I_NEW; @@ -1300,6 +1303,16 @@ xfs_setup_inode( i_size_write(inode, ip->i_disk_size); xfs_diflags_to_iflags(ip, true); + /* + * Mark our metadata files as private so that LSMs and the ACL code + * don't try to add their own metadata or reason about these files, + * and users cannot ever obtain file handles to them. + */ + if (is_meta) { + inode->i_flags |= S_PRIVATE; + inode->i_opflags &= ~IOP_XATTR; + } + if (S_ISDIR(inode->i_mode)) { /* * We set the i_rwsem class here to avoid potential races with |