From 4eac34529bce2b4cca9be90a6903c965baa8193c Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Fri, 10 Aug 2007 14:32:33 +0200 Subject: [PATCH] [S390] vmur: add "top of queue" sanity check for reader open If the z/VM reader is already open, it can happen that after opening the Linux reader device, not the topmost file is processed. According the semantics of the Linux z/VM unit record device driver, always the topmost file has to be processed. With this fix an error is returned if that is not the case. Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- drivers/s390/char/vmur.c | 7 ++++++- drivers/s390/char/vmur.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c index 04395c0f99..a9d58629e7 100644 --- a/drivers/s390/char/vmur.c +++ b/drivers/s390/char/vmur.c @@ -565,9 +565,14 @@ static int verify_device(struct urdev *urd) return -ENOMEM; rc = diag_read_file(urd->dev_id.devno, buf); kfree(buf); - if ((rc != 0) && (rc != -ENODATA)) /* EOF does not hurt */ return rc; + /* check if the file on top of the queue is open now */ + rc = diag_read_next_file_info(&fcb, 0); + if (rc) + return rc; + if (!(fcb.file_stat & FLG_IN_USE)) + return -EMFILE; return 0; default: return -ENOTSUPP; diff --git a/drivers/s390/char/vmur.h b/drivers/s390/char/vmur.h index 522a9dfaa2..2b3c564e04 100644 --- a/drivers/s390/char/vmur.h +++ b/drivers/s390/char/vmur.h @@ -53,6 +53,7 @@ struct file_control_block { #define FLG_SYSTEM_HOLD 0x04 #define FLG_CP_DUMP 0x10 #define FLG_USER_HOLD 0x20 +#define FLG_IN_USE 0x80 /* * A struct urdev is created for each ur device that is made available -- 2.39.5