From: Andrey Albershteyn aalbersh@redhat.com
commit e23d7e82b707d1d0a627e334fb46370e4f772c11 upstream.
There's an issue that if special files is created before quota project is enabled, then it's not possible to link this file. This works fine for normal files. This happens because xfs_quota skips special files (no ioctls to set necessary flags). The check for having the same project ID for source and destination then fails as source file doesn't have any ID.
mkfs.xfs -f /dev/sda mount -o prjquota /dev/sda /mnt/test
mkdir /mnt/test/foo mkfifo /mnt/test/foo/fifo1
xfs_quota -xc "project -sp /mnt/test/foo 9" /mnt/test
Setting up project 9 (path /mnt/test/foo)... xfs_quota: skipping special file /mnt/test/foo/fifo1 Processed 1 (/etc/projects and cmdline) paths for project 9 with recursion depth infinite (-1).
ln /mnt/test/foo/fifo1 /mnt/test/foo/fifo1_link
ln: failed to create hard link '/mnt/test/testdir/fifo1_link' => '/mnt/test/testdir/fifo1': Invalid cross-device link
mkfifo /mnt/test/foo/fifo2 ln /mnt/test/foo/fifo2 /mnt/test/foo/fifo2_link
Fix this by allowing linking of special files to the project quota if special files doesn't have any ID set (ID = 0).
Signed-off-by: Andrey Albershteyn aalbersh@redhat.com Reviewed-by: "Darrick J. Wong" djwong@kernel.org Signed-off-by: Chandan Babu R chandanbabu@kernel.org Signed-off-by: Catherine Hoang catherine.hoang@oracle.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/xfs_inode.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index f9d29acd72b9..efb6b8f35617 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -1239,8 +1239,19 @@ xfs_link( */ if (unlikely((tdp->i_diflags & XFS_DIFLAG_PROJINHERIT) && tdp->i_projid != sip->i_projid)) { - error = -EXDEV; - goto error_return; + /* + * Project quota setup skips special files which can + * leave inodes in a PROJINHERIT directory without a + * project ID set. We need to allow links to be made + * to these "project-less" inodes because userspace + * expects them to succeed after project ID setup, + * but everything else should be rejected. + */ + if (!special_file(VFS_I(sip)->i_mode) || + sip->i_projid != 0) { + error = -EXDEV; + goto error_return; + } }
if (!resblks) {