Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On Thu, 1 Feb 2007, Andrew Morton wrote:
> On Thu, 1 Feb 2007 15:34:29 -0800
> bugme-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=7919
> >
> > Summary: Tape dies if wrong block size used
> > Kernel Version: 2.6.20-rc5
> > Status: NEW
> > Severity: normal
> > Owner: scsi_drivers-other@kernel-bugs.osdl.org
> > Submitter: dmartin@sccd.ctc.edu
> >
> >
> > Most recent kernel where this bug did *NOT* occur: 2.6.17.14
> >
> > Other Kernels Tested and Results:
> >
> > OK 2.6.15.7
> > OK 2.6.16.37
> > OK 2.6.17.14
> > BAD 2.6.18.6
> > BAD 2.6.18-1.2869.fc6
> > BAD 2.6.19.2 +
> > BAD 2.6.20-rc5
> >
> > NOTE: 2.6.18-1.2869.fc6 is a Fedora modified kernel, all others are from kernel.org
> >
...
> > Steps to reproduce:
> > Get a Adaptec AHA-2940U/UW/D / AIC-7881U card and a tape drive,
> > install a recent kernel
> > set the tape block size - mt setblk 4096
> > read from or write to tape using wrong block size - tar -b 7 -cvf /dev/tape foo
> >
Write does not trigger this bug because the driver refuses in fixed block
mode writes that are not a multiple of the block size. Read does trigger
it in my system.
The bug is not associated with any specific HBA. st tries to do direct i/o
in fixed block mode with reads that are not a multiple of tape block size.
The patch in this message fixes the st problem by switching to using the
driver buffer up to the next close of the device file in fixed block mode
if the user asks for a read like this.
I don't know why the bug has surfaced only after 2.6.17 although the st
problem is old. There may be another bug in the block subsystem and this
patch works around it. However, the patch fixes a problem in st and in
this way it is a valid fix.
This patch may also fix the bug 7900.
The patch compiles and is lightly tested.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
On Wed, 24 Jan 2007, Andrew Morton wrote:
> On Mon, 22 Jan 2007 13:07:20 -0800
> bugme-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=7864
> >
> > Summary: A MTIOCTOP/MTWEOF within the early warning will cause
> > the file number to be incorrect
> > Kernel Version: 2.6.19.2
> > Status: NEW
> > Severity: low
> > Owner: io_scsi@kernel-bugs.osdl.org
> > Submitter: ce_reisinger@yahoo.com
> >
> >
> > Write records to a SCSI tape until a write fails with a ENOSPC (you have reached
> > early warning.
> > Now perform a:
> > struct mtget before, after;
> > ioctl(fd, MTIOCGET, &before);
> > struct mtop mtop = { MTWEOF, 1 };
> > ioctl(fd, MTIOCTOP, &mtop);
> > ioctl(fd, MTIOCGET, &after);
> >
> > Check the value of mt_fileno in the before and after structures. Notice the
> > after is 2 greater then the before.
> >
> > The problem appears to be in the block of code starting at line 2817 in st.c.
> > This block is entered because the drive did return a CHECK CONDITION with NO
> > SENSE and the SENSE_EOM bit set. At lines 2824/5 the fileno is incremented. But
> > it has already been increased by the number of filemarks requested by the
> > MTIOCTOP. I believe that the residue count in the sense data should be
> > subtracted from fileno, not a increment as is done.
> >
>
> Thanks. Could you please send us a tested patch to fix these things, as
> per http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt ?
>
The analysis is basically correct and explains the bug. According to the
SCSI standards, the sense code is NO SENSE or RECOVERED ERROR in case
writing filemark(s) succeeds. If it fails (partly or completely) the sense
code is VOLUME OVERFLOW. The patch below is tested to fix the case when
one filemark is successfully written after the EOM early warning. It
should also fix the case at real EOM but this has not been tested.
Carl, thanks for reporting the bug and providing the analysis for the fix.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Printk -> sdev_printk change originally from Luben Tuikov
<ltuikov@yahoo.com>. Loglevel changes prompted by Matthew Wilcox
<matthew@wil.cx>.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Based on the original patch from Hannes Reinecke <hare@suse.de>
Fix st_open() to return -ENOMEDIUM instead of -EIO if no medium is
found.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Notice and handle sysfs errors in module init, tape init
- Properly unwind errors in module init
- Remove bogus st_sysfs_class==NULL test, it is guaranteed !NULL at that point
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Convert this:
st0: Error with sense data: <6>st: Current: sense key: Illegal Request
Additional sense: Invalid field in cdb
To this:
st0: Current: sense key: Illegal Request
Additional sense: Invalid field in cdb
Signed-off-by: Luben Tuikov <ltuikov@yahoo.com>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
I noticed that in_use in st_buffer is not used. The patch below
against 2.6.17-rc3 removes it, assuming there is no future use for it.
It was tested in a sparc SS20 with a DLT4000.
Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Pass the POSIX lock owner ID to the flush operation.
This is useful for filesystems which don't want to store any locking state
in inode->i_flock but want to handle locking/unlocking POSIX locks
internally. FUSE is one such filesystem but I think it possible that some
network filesystems would need this also.
Also add a flag to indicate that a POSIX locking request was generated by
close(), so filesystems using the above feature won't send an extra locking
request in this case.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove
duplicates of the macro.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
As devfs has been disabled from the kernel tree for a number of months
now (5 to be exact), here's a patch against 2.6.16-rc1-git1 that removes
support for it from the SCSI subsystem.
The patch also removes the scsi_disk devfs_name field as it's no longer
needed.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
LLDDs should never see REQ_BLOCK_PC requests, we can handle them just
fine in the core code. There is a small behaviour change in that some
check in sr's rw_intr are bypassed, but I consider the old behaviour
a bug.
Mike found this cleanup opportunity and provdided early patches, so all
the credit goes to him, even if I redid the patches from scratch beause
that was easier than forward-porting the old patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This merge is pretty extensive. The conflict is over the new
req->retries parameter, so I had to change the prototype to
scsi_setup_blk_pc_cmnd() and the usage in sd, sr and st.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Patch from Kai minus last sg_segs clearing which was merged already.
> > Was there a oops or lockup or any debug output you can send me? I will try
> > some more large request tests with scsi_debug. You also have to compile your
> > kernel with SCSI_MAX_PHYS_SEGMENTS == 255 to get larger requests now.
>
It was an oops in sgl_unmap_user_pages(). The reason is this:
/* XXX: just for debug. Remove when PageReserved is removed */
BUG_ON(PageReserved(page));
I was using /dev/zero as input and it triggers this. When I used a file as
input, this did not trigger. Should this BUG_ON be removed?
In the same log I noticed that there was another ->sg_segs inconsistency.
Also, the field ->last_SRpnt was not reset when scsi_execute_async()
failed. This caused the error message "Async command already active"
later and prevented proper close.
While doing the changes, I noticed that the current code (since
2.6.0-test4) does not set the pages dirty when reading with direct i/o.
All of these st problems (including the one I sent earlier) are fixed in
the patch at the end of this message. These fixes should probably be
included already in 2.6.15.
After these fixes, the tape seems to operate as expected. Without other
changes, the largest block size with sym53c896 SCSI adapter is 384 kB. The
maximum number of sg segments is set to 96 and clustering is disabled in
the driver. 96 x 4 kB = 384 kB. OK.
I enabled clustering and set max_sectors to 10000 in the SCSI HBA driver.
Now the block size limit is 5000 kB as expected.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
convert st to always send scatterlists and kill scsi_request
usage.
This is the same as last time as it was posted, but with Kai's patches
merged and we now pass the bytes value to scsi_execute_async.
TODO:
- move DIO code to common place or make block layers usable for ULDs.
- move buffer allocation code to common place for all ULDs to use. And
make buffer allocation code handle all queue limits so we can find
out about problems before calling scsi_execute_async.
- move indirect (copy_to/from_user) paths commone place or make block
layers usable for ULDs.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
sd does not allow scsi_io_completion to retry commands for
SG_IO requests, and it make sense that it should not happen for st
SG_IO commands too. If for st we hit the bottom of scsi_io_completion
we will probably screw things up pretty bad. This patch returns to the
block layer that the whole command completed and relies on the caller to check
the request errors field. For initialization commands like in sd, this adds
the previous behavior where scsi_io_completion did not process the error.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This follows on from Jens' patch and consolidates all of the ULD
separate handlers for REQ_BLOCK_PC into a single call which has his
fix for our direction bug.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
patch below marks a few scsi core datastructures as const, so that they end up
in the .rodata section and don't cacheline share with things that get dirtied
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2.6.15-rc1 made sg's st_unmap_user_pages and st's sgl_unmap_user_pages
BUG on a PageReserved page. But that's wrong: they could be unmapping
the ZERO_PAGE, which is marked PG_reserved; and perhaps others (while
get_user_pages is still permitted on VM_PFNMAP areas - that may change).
More change is needed here: sg claims to dirty even pages written from,
and st claims not to dirty even pages read into; and SetPageDirty is not
adequate for this nowadays. Fixes to those follow in a later patch: for
the moment just fix the 2.6.15 regression.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Nick and I had already been looking at drivers/scsi/{sg.c,st.c},
brought there by __put_page in sg.c's peculiar sg_rb_correct4mmap,
which we'd like to remove. But that's irrelevant to your pain, except...
One extract from the patches I'd like to send Doug and Kai for 2.6.15
or 2.6.16 is this below: since the incomplete get_user_pages path omits
to reset res, but has already released all the pages, it will result in
premature freeing of user pages, and behaviour just like you've seen.
Though I'd have thought incomplete get_user_pages was an exceptional
case, and a bit surprised you'd encounter it. Perhaps there's some
other premature freeing in the driver, and this instance has nothing
whatever to do with it.
If the problem were easily reproducible, it'd be great if you could
try this patch; but I think you've said it's not :-(
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This is the drivers/scsi/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in drivers/scsi/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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 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>
This fixes an issue in scsi command initialization from a request
where sd, sr, st, and scsi_lib all fail to copy the request's
cmd_len to the scsi command's cmd_len field.
Signed-off-by: Timothy Thelin <timothy.thelin@wdc.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
reported by Doug Gilbert and fixed by him in sg.c (see [PATCH] sg direct
io/mmap oops). Doug fixed the comparison in sg.c. This fix for st.c does not
touch the comparison but makes both arguments signed to remove the
problem. The new code is adapted from linux/fs/bio.c.
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
I have rediffed the patch against 2.6.13-rc5, done a couple of cosmetic
cleanups, and run some tests. Brian King has acknowledged that it fixes the
problems he has seen. Seems mature enough for inclusion into 2.6.14 (or
later)?
Nate's explanation of the changes:
I've attached patches against 2.6.13rc2. These are basically identical
to my earlier patches, as I found that all issues I'd seen in earlier
kernels still existed in this kernel.
To summarize, the changes are: (more details in my original email)
- add a kref to the scsi_tape structure, and associate reference
counting stuff
- set sr_request->end_io = blk_end_sync_rq so we get notified when an IO
is rejected when the device goes away
- check rq_status when IOs complete, else we don't know that IOs
rejected for a dead device in fact did not complete
- change last_SRpnt so it's set before an async IO is issued (in case
st_sleep_done is bypassed)
- fix a bogus use of last_SRpnt in st_chk_result
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Removing the SCSI tape module results in an oops in class_device_destroy if
any devices are present. The patch at the end of this message fixes the bug
by moving class_destroy() later in exit_st() so that the class still exists
when devices are removed. (The bug is old but class_simple_device_remove() did
nothing when the class did not exist.)
The patch also fixes a "class leak" in init_st() error path.
I would like to get this into 2.6.13 but it may be too late?
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch is against 2.6.12-rc3 + linus-patch from April 30. The patch
contains the following fixes:
- CAP_SYS_RAWIO is used instead of CAP_SYS_ADMIN; fix from Alan Cox
- only direct sending of SCSI commands requires this permission
- the st status is modified is successful unload is performed using
SCSI_IOCTL_STOP_UNIT
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
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!
