Remove PageReserved() calls from core code by tightening VM_RESERVED
handling in mm/ to cover PageReserved functionality.
PageReserved special casing is removed from get_page and put_page.
All setting and clearing of PageReserved is retained, and it is now flagged
in the page_alloc checks to help ensure we don't introduce any refcount
based freeing of Reserved pages.
MAP_PRIVATE, PROT_WRITE of VM_RESERVED regions is tentatively being
deprecated. We never completely handled it correctly anyway, and is be
reintroduced in future if required (Hugh has a proof of concept).
Once PageReserved() calls are removed from kernel/power/swsusp.c, and all
arch/ and driver code, the Set and Clear calls, and the PG_reserved bit can
be trivially removed.
Last real user of PageReserved is swsusp, which uses PageReserved to
determine whether a struct page points to valid memory or not. This still
needs to be addressed (a generic page_is_ram() should work).
A last caveat: the ZERO_PAGE is now refcounted and managed with rmap (and
thus mapcounted and count towards shared rss). These writes to the struct
page could cause excessive cacheline bouncing on big systems. There are a
number of ways this could be addressed if it is an issue.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Refcount bug fix for filemap_xip.c
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch uses sg_set_buf/sg_init_one in some places where it was
duplicated.
Signed-off-by: David Hardeman <david@2gen.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables. As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The previous patch adding the ability to nest struct class_device
changed the paramaters to the call class_device_create(). This patch
fixes up all in-kernel users of the function.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Driver core: pass interface to class intreface methods
Pass interface as argument to add() and remove() class interface
methods. This way a subsystem can implement generic add/remove
handlers and then call interface-specific ones.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A bunch of create_proc_dir_entry() calls creating directories had crept
in since the last sweep; converted to proc_mkdir().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We fix the oops by enforcing the host state model. There have also
been two extra states added: SHOST_CANCEL_RECOVERY and
SHOST_DEL_RECOVERY so we can take the model through host removal while
the recovery thread is active.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch adopts the same solution as proposed by Kai M. in
a post titled: "[PATCH] SCSI tape signed/unsigned fix".
The fix is in a function that the sg driver borrowed from
the st driver so its maintenance is a little easier if
the functions remain the same after the fix.
- change nr_pages type from unsigned to signed so errors
from get_user_pages() call are properly handled
Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
I know that scsi procfs is legacy code but this is a fix for a memory leak.
While reading through sg.c I realized that the implementation of
/proc/scsi/sg/devices with seq_file is leaking memory due to freeing the
pointer returned by the next() iterator method. Since next() might return
NULL or an error this is wrong. This patch fixes it through using the
seq_files private field for holding the reference to the iterator object.
Here is a small bash script to trigger the leak. Use slabtop to watch
the size-32 usage grow and grow.
#!/bin/sh
while true; do
cat /proc/scsi/sg/devices > /dev/null
done
Signed-off-by: Jan Blunck <j.blunck@tu-harburg.de>
Acked-by: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Migrate the current SCSI host state model to a model like SCSI
device is using.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
A problem exists todayin the sg driver that if an SG_IO request is
outstanding to a device when it is removed from the system. The
system may oops if that command completes later in time.
1. sg_remove gets called
2. sg_remove calls sg_finish_req_req on all pending requests
This removes the Sg_request's from the headrp list in the Sg_fd
3. The sleeping SG_IO ioctl is woken. It does nothing and returns.
4. The caller closes the fd, which invokes sg_release
5. sg_release calls sg_remove_sfp. It finds no outstanding commands
since the headrp list is empty, so it calls __sg_remove_sfp,
which frees the sfp.
6. Now when sg_cmd_done gets called, sg uses upper_private_data in
the Scsi_Request, which should point to the srp, which has been
freed, so it points to freed memory.
7. sg then dereferences the srp pointer to get the sfp, and we oops.
The fix is to NULL out the upper_private_data field in this path,
which sg_cmd_done already checks for, which will prevent the oops
from occurring.
cpu 0x1: Vector: 300 (Data Access) at [c00000000fff7aa0]
pc: d0000000002bbea8: .sg_cmd_done+0x70/0x394 [sg]
lr: d000000000073304: .scsi_finish_command+0x10c/0x130 [scsi_mod]
sp: c00000000fff7d20
msr: 8000000000009032
dar: 2f70726f63202f78
dsisr: 40000000
current = 0xc0000000024589b0
paca = 0xc0000000003da800
pid = 7, comm = events/1
[c00000000fff7dc0] d000000000073304 .scsi_finish_command+0x10c/0x130 [scsi_mod]
[c00000000fff7e50] d00000000007317c .scsi_softirq+0x140/0x168 [scsi_mod]
[c00000000fff7ef0] c0000000000634dc .__do_softirq+0xa0/0x17c
[c00000000fff7f90] c000000000018430 .call_do_softirq+0x14/0x24
[c00000000ed472e0] c0000000000142e0 .do_softirq+0x74/0x9c
[c00000000ed47370] c000000000013c9c .do_IRQ+0xe8/0x100
[c00000000ed473f0] c00000000000ae34 HardwareInterrupt_entry+0x8/0x54
c00000000003df28 .smp_call_function+0
x100/0x1d0
[c00000000ed47780] c0000000000ba99c .invalidate_bh_lrus+0x30/0x70
[c00000000ed47810] c0000000000b91a0 .invalidate_bdev+0x18/0x3c
[c00000000ed478a0] c0000000000da7b8 .__invalidate_device+0x70/0x94
[c00000000ed47930] c0000000001d40bc .invalidate_partition+0x4c/0x7c
[c00000000ed479c0] c00000000010a944 .del_gendisk+0x48/0x15c
[c00000000ed47a50] d00000000003d55c .sd_remove+0x34/0xe4 [sd_mod]
[c00000000ed47ae0] c0000000001c5d30 .device_release_driver+0x90/0xb4
[c00000000ed47b70] c0000000001c6130 .bus_remove_device+0xb0/0x12c
[c00000000ed47c00] c0000000001c4378 .device_del+0x120/0x198
[c00000000ed47ca0] d00000000007dcdc .scsi_remove_device+0xb4/0x194 [scsi_mod]
[c00000000ed47d30] d0000000000a5864 .ipr_worker_thread+0x1d4/0x27c [ipr]
[c00000000ed47dd0] c0000000000734c4 .worker_thread+0x238/0x2f4
[c00000000ed47ee0] c0000000000796c0 .kthread+0xcc/0x11c
[c00000000ed47f90] c000000000018ad0 .kernel_thread+0x4c/0x6c
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
these have been wrappers for the generic dma direction bits since 2.5.x.
This patch converts the few remaining drivers and removes the macros.
Arjan noticed there's some hunk in here that shouldn't. Updated patch
below:
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have the scsi_print_* functions in the proper namespace for a long
time now and there weren't a lot users left.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The attachment combines the most recent patch from
Yum Rayan <yum.rayan@gmail.com> (to reduce sg stack
usage), Adrian Bunk <bunk@stusta.de> (to fix check
after use) and me (fix elapsed time calculation
(duration) on ia64 machines).
I have modified the patch from Yum Rayan so kmalloc()
in sg_read() is only called for the (rare) code paths
that need them.
Changelog:
- reduce stack usage in sg_ioctl() and sg_read()
- fix check after use in sg_mmap()
- hold duration internally in milliseconds and
check current time later than held time
Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
