ceph: flush the dirty caps immediatelly when quota is approaching

When the quota is approaching we need to notify it to the MDS as
soon as possible, or the client could write to the directory more
than expected.

This will flush the dirty caps without delaying after each write,
though this couldn't prevent the real size of a directory exceed
the quota but could prevent it as soon as possible.

Link: https://tracker.ceph.com/issues/56180
Signed-off-by: Xiubo Li <[e-mail]>
Reviewed-by: Luís Henriques <[e-mail]>
Signed-off-by: Ilya Dryomov <[e-mail]>

fs/ceph/caps.c

···
 	}
 
 	dout("check_caps %llx.%llx file_want %s used %s dirty %s flushing %s"
-	     " issued %s revoking %s retain %s %s%s\n", ceph_vinop(inode),
+	     " issued %s revoking %s retain %s %s%s%s\n", ceph_vinop(inode),
 	     ceph_cap_string(file_wanted),
 	     ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
 	     ceph_cap_string(ci->i_flushing_caps),
 	     ceph_cap_string(issued), ceph_cap_string(revoking),
 	     ceph_cap_string(retain),
 	     (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
-	     (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
+	     (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "",
+	     (flags & CHECK_CAPS_NOINVAL) ? " NOINVAL" : "");
 
 	/*
 	 * If we no longer need to hold onto old our caps, and we may

fs/ceph/file.c

···
 		if (dirty)
 			__mark_inode_dirty(inode, dirty);
 		if (ceph_quota_is_max_bytes_approaching(inode, iocb->ki_pos))
-			ceph_check_caps(ci, 0, NULL);
+			ceph_check_caps(ci, CHECK_CAPS_FLUSH, NULL);
 	}
 
 	dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
···
 		/* Let the MDS know about dst file size change */
 		if (ceph_inode_set_size(dst_inode, dst_off) ||
 		    ceph_quota_is_max_bytes_approaching(dst_inode, dst_off))
-			ceph_check_caps(dst_ci, CHECK_CAPS_AUTHONLY, NULL);
+			ceph_check_caps(dst_ci, CHECK_CAPS_AUTHONLY | CHECK_CAPS_FLUSH,
+					NULL);
 	}
 	/* Mark Fw dirty */
 	spin_lock(&dst_ci->i_ceph_lock);