ntfs: fix a self-deadlock on writes to non-resident named streams

The stream write ioctl holds the stream mapping's invalidate lock
across ntfs_inode_attr_pwrite(), which calls
ntfs_extend_initialized_size() for named streams, and that function
takes the same lock again, before the check that could skip the
extension.  A write to a non-resident named stream through
NTFS_IOC_STREAM_WRITE deadlocks on itself.

The ioctl is the only caller that reaches the named stream branch of
ntfs_inode_attr_pwrite(), and it always holds the lock there, so
split off __ntfs_extend_initialized_size(), which expects the caller
to hold the invalidate lock, and call it from that branch.  The write
and mmap paths keep taking the lock themselves.

Fixes: 3f11c48d4f94 ("ntfs: add pathname access for named streams")
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Reviewed-by: Baolin Liu <liubaolin@kylinos.cn>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions