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  1. 09 Sep, 2005 6 commits
    • Douglas Gilbert's avatar
      [SCSI] sg: do not set VM_IO flag on mmap-ed pages · 1c8e71d7
      Douglas Gilbert authored 
      Further to the problem discussed in this post:
http://marc.theaimsgroup.com/?l=linux-scsi&m=112540053711489&w=2

It seems that the sg driver does not need to set the VM_IO flag
on pages that it memory maps to the user space since they are
not from the IO space. Ahmed Teirelbar <ahmed.teirelbar@adic.com>
wants the facility and has tested this patch as I have without
adverse effects.

The oops protection is still important. Some users really did
try and use dio transfers from the sg driver to memory mapped
IO space (on a video capture card if my memory serves) during the
lk 2.4 series. I'm not sure how successful it was but that will
now be politely refused in lk 2.6.13+ .

Changelog:
   - set the page flags for sg's reserved buffer mmap-ed
     to the user space to VM_RESERVED (rather than
     VM_RESERVED | VM_IO )
Signed-off-by: default avatarDouglas Gilbert <dougg@torque.net>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      1c8e71d7
    • James Bottomley's avatar
      [SCSI] SCSI core: fix leakage of scsi_cmnd's · 788ce43a
      James Bottomley authored 
      Actually, just one problem and one cosmetic fix:

1) We need to dequeue for the loop and kill case (it seems easiest
simply to dequeue in the scsi_kill_request() routine)
2) There's no real need to drop the queue lock.  __scsi_done() is lock
agnostic, so since there's no requirement, let's just leave it in to
avoid any locking issues.
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      788ce43a
    • James Bottomley's avatar
      [SCSI] SCSI core: fix leakage of scsi_cmnd's · e91442b6
      James Bottomley authored 
      From: 	Alan Stern <stern@rowland.harvard.edu>

This patch (as559b) adds a new routine, scsi_unprep_request, which
gets called every place a request is requeued.  (That includes
scsi_queue_insert as well as scsi_requeue_command.)  It also changes
scsi_kill_requests to make it call __scsi_done with result equal to
DID_NO_CONNECT << 16.  (I'm not sure if it's necessary to call
scsi_init_cmd_errh here; maybe you can check on that.)  Finally, the
patch changes the return value from scsi_end_request, to avoid
returning a stale pointer in the case where the request was requeued.
Fortunately the return value is used in only place, and the change
actually simplified it.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>

Rejections fixed up and
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      e91442b6
    • Neil Brown's avatar
      [SCSI] fix possible deadlock in scsi_lib.c · 286f3e13
      Neil Brown authored 
        If a filesystem, while writing out data, decides that it is good
to issue a cache flush on a SCSI drive (or other 'sd' device), it will
call blkdev_issue_flush which calls ->issue_flush_fn which is
scsi_issue_flush_fn.
This calls sd_issue_flush which calls sd_sync_cache, which calls
scsi_execute_request.
This will (as sshdr != NULL) call
    kmalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL)

If memory is tight, the presence of GFP_KERNEL may cause write
requests to be sent to some filesystem to free up memory, however if
that filesystem is waiting for the issue_flush_fn to complete, you
could get a deadlock.

I wonder if it might be more appropriate to use GFP_NOIO as in the
following patch.

I wonder if it might be even more appropriate to cope better with a
kmalloc failure, especially as in this use, sd_sync_cache only will
use the sense information to print out a more informative error
message.
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      286f3e13
    • Alan Stern's avatar
      [SCSI] fix callers of scsi_remove_device() who already hold the scan muted · 903f4fed
      Alan Stern authored 
      This patch (as544) adds a private entry point to scsi_remove_device, for
use when callers already own the scan_mutex.  The appropriate callers are
modified to use the new entry point.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      903f4fed
    • Alan Stern's avatar
      [SCSI] add missing scan mutex to scsi_scan_target() · e517d313
      Alan Stern authored 
      This patch (as543) adds a private entry point to scsi_scan_target, for use
when the caller already owns the scan_mutex, and updates the kerneldoc for
that routine (which was badly out-of-date).  It converts scsi_scan_channel
to use the new entry point.  Lastly, it modifies scsi_get_host_dev to make
it acquire the scan_mutex, necessary since the routine adds a new
scsi_device even if it doesn't do any actual scanning.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
      e517d313
  3. 08 Sep, 2005 27 commits
  5. 07 Sep, 2005 7 commits
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