From 7b3d9545f9ac8b31528dd2d6d8ec8d19922917b8 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 6 Jan 2008 10:17:12 -0800 Subject: Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund Cc: James Bottomley Cc: Matthew Wilcox Cc: Ingo Molnar Cc: Andrew Morton Signed-off-by: Linus Torvalds --- include/scsi/scsi_driver.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/scsi/scsi_driver.h') diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h index 56a3047..1f5ca7f 100644 --- a/include/scsi/scsi_driver.h +++ b/include/scsi/scsi_driver.h @@ -15,6 +15,7 @@ struct scsi_driver { struct device_driver gendrv; void (*rescan)(struct device *); + int (*done)(struct scsi_cmnd *); }; #define to_scsi_driver(drv) \ container_of((drv), struct scsi_driver, gendrv) -- cgit v1.1