Typical Linux style is "return -EINVAL", not "return(-EINVAL)".
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a few spelling errors.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It's easier to verify loop bounds if the array name is mentioned the for()
statement that steps through the array.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We already print "cciss: using DAC cycles" or similar for every adapter found:
why not just identify the device we're talking about and include other useful
information?

Jeff Garzik <jeff@garzik.org>:

  Although this patch is correct, I would consider using dev_printk() rather
  than referencing pci_name() in printk() arguments.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We should call pci_request_regions() to claim all resources the device
decodes.  Previously, we claimed only the I/O port range.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If something fails after we call pci_enable_device(), we should call
pci_disable_device() before returning the failure.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

New section on creating an external initramfs image using cpio (with
script), a warning about bad advice in the cpio man page, a bit of
debugging advice (hello world and rdinit=/bin/sh), and a few minor tweaks
to other parts of it.
Signed-off-by: NRob Landley <rob@landley.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update smbiod to use kthread instead of deprecated kernel_thread.

[akpm@osdl.org: cleanup]
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update loop.c to use a kthread instead of a deprecated kernel_thread for
loop devices.

[akpm@osdl.org: don't change the thread's name]
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make kernel-doc corrections & additions to lib/crc*.c.  Add crc functions to
kernel-api.tmpl in DocBook.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a new chapter for kernel-lib functions to kernel-api.tmpl.  Add
lib/cmdline.c to the new kernel-lib chapter.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make corrections/fixes to kernel-doc in lib/bitmap.c and include it in DocBook
template.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

coverity found two needless checks in vfs_inode.c (cid #1165 and #1164)
In both cases inode is always NULL when we goto error; either because it
is still initialized to NULL or is set to NULL explicitly. This patch
simply removes these checks to save some code.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix debug-only printk syntax error.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When the verbose (-v) option is used with scripts/kernel-doc, this option
reports when the kernel-doc format is malformed and apparently contains
function description lines before function parameters.  In these cases, the
kernel-doc script will print something like: Warning(filemap.c:335):
contents before sections

I have fixed the problems in mm/filemap.c and added lots of kernel-doc to
that file (posted to the linux-mm mailing list Mon.  2006-June-12).

The real goal (as requested by Andrew Morton) is to allow the short
function description to be more than one line long.  This patch is both a
kernel-doc checker and a tool en route to that goal.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

VFS uses current->files pointer as lock owner ID, and it wouldn't be
prudent to expose this value to userspace.  So scramble it with XTEA using
a per connection random key, known only to the kernel.  Only one direction
needs to be implemented, since the ID is never sent in the reverse
direction.

The XTEA algorithm is implemented inline since it's simple enough to do so,
and this adds less complexity than if the crypto API were used.

Thanks to Jesper Juhl for the idea.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add synchronous request interruption.  This is needed for file locking
operations which have to be interruptible.  However filesystem may implement
interruptibility of other operations (e.g.  like NFS 'intr' mount option).
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rename the 'interrupted' flag to 'aborted', since it indicates exactly that,
and next patch will introduce an 'interrupted' flag for a
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

All POSIX locks owned by the current task are removed on close().  If the
FLUSH request resulting initiated by close() fails to reach userspace, there
might be locks remaining, which cannot be removed.

The only reason it could fail, is if allocating the request fails.  In this
case use the request reserved for RELEASE, or if that is currently used by
another FLUSH, wait for it to become available.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds POSIX file locking support to the fuse interface.

This implementation doesn't keep any locking state in kernel.  Unlocking on
close() is handled by the FLUSH message, which now contains the lock owner id.

Mandatory locking is not supported.  The filesystem may enfoce mandatory
locking in userspace if needed.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a control filesystem to fuse, replacing the attributes currently exported
through sysfs.  An empty directory '/sys/fs/fuse/connections' is still created
in sysfs, and mounting the control filesystem here provides backward
compatibility.

Advantages of the control filesystem over the previous solution:

  - allows the object directory and the attributes to be owned by the
    filesystem owner, hence letting unpriviled users abort the
    filesystem connection

  - does not suffer from module unload race

[akpm@osdl.org: fix this fs for recent dhowells depredations]
[akpm@osdl.org: fix 64-bit printk warnings]
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't put requests into the background when a fatal interrupt occurs while the
request is in userspace.  This removes a major wart from the implementation.

Backgrounding of requests was introduced to allow breaking of deadlocks.
However now the same can be achieved by aborting the filesystem through the
'abort' sysfs attribute.

This is a change in the interface, but should not cause problems, since these
kinds of deadlocks never happen during normal operation.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The following patches add POSIX file locking to the fuse interface.

Additional changes ralated to this are:

  - asynchronous interrupt of requests by SIGKILL no longer supported

  - separate control filesystem, instead of using sysfs objects

  - add support for synchronously interrupting requests

Details are documented in Documentation/filesystems/fuse.txt throughout the
patches.

This patch:

Have fuse.h use MISC_MAJOR rather than a hardcoded '10'.
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make another couple of alterations to the memory barrier document following
suggestions by Alan Stern and in co-operation with Paul McKenney:

 (*) Rework the point of introduction of memory barriers and the description
     of what they are to reiterate why they're needed.

 (*) Modify a statement about the use of data dependency barriers to note that
     other barriers can be used instead (as they imply DD-barriers).
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-By: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Another bunch of checks in the char drivers .put_char() and .write()
routines, where tty can never be NULL.  This patch removes these checks to
save some code.  Coverity choked at those with the following bug ids:

isicom.c  767, 766
specialix.c 773, 774
synclink_cs.c 779, 781
synclink_gt.c 784, 785
synclinkmp.c 784, 785
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update my contact information in CREDITS.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I've found a case where invalid dentrys in a mount tree, waiting to be
cleaned up by d_invalidate, prevent the expected expire.

In this case dentrys created during a lookup for which a mount fails or has
no entry in the mount map contribute to the d_count of the parent dentry.
These dentrys may not be invalidated prior to comparing the interanl usage
count of valid autofs dentrys against the dentry d_count which makes a
mount tree appear busy so it doesn't expire.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

coverity choked at another two !tty checks, in places where tty can
never be NULL. Since it removes some code we should remove
these checks. (Coverity ids #763,#762)

Signed-off-by Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

coverity choked at two !tty checks, in places where tty can never be NULL.
Since it removes some code we should remove these checks.  (Coverity ids
#763,#762)

[akpm@osdl.org: even cleaner!]
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If futexes are disabled we fail to link on ppc64.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

An update to the RCU documentation calling out the
self-limiting-update-rate advantages of synchronize_rcu(), and describing
how to use call_rcu() in a way that results in self-limiting updates.
Self-limiting updates are important to avoiding RCU-induced OOM in face of
denial-of-service attacks.
Signed-off-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Backoff readahead size exponentially on I/O error.

Michael Tokarev <mjt@tls.msk.ru> described the problem as:

[QUOTE]
Suppose there's a CD-rom with a scratch/etc, one sector is unreadable.
In order to "fix" it, one have to read it and write to another CD-rom,
or something.. or just ignore the error (if it's just a skip in a video
stream).  Let's assume the unreadable block is number U.

But current behavior is just insane.  An application requests block
number N, which is before U. Kernel tries to read-ahead blocks N..U.
Cdrom drive tries to read it, re-read it.. for some time.  Finally,
when all the N..U-1 blocks are read, kernel returns block number N
(as requested) to an application, successefully.

Now an app requests block number N+1, and kernel tries to read
blocks N+1..U+1.  Retrying again as in previous step.

And so on, up to when an app requests block number U-1.  And when,
finally, it requests block U, it receives read error.

So, kernel currentry tries to re-read the same failing block as
many times as the current readahead value (256 (times?) by default).

This whole process already killed my cdrom drive (I posted about it
to LKML several months ago) - literally, the drive has fried, and
does not work anymore.  Ofcourse that problem was a bug in firmware
(or whatever) of the drive *too*, but.. main problem with that is
current readahead logic as described above.
[/QUOTE]

Which was confirmed by Jens Axboe <axboe@suse.de>:

[QUOTE]
For ide-cd, it tends do only end the first part of the request on a
medium error. So you may see a lot of repeats :/
[/QUOTE]

With this patch, retries are expected to be reduced from, say, 256, to 5.

[akpm@osdl.org: cleanups]
Signed-off-by: NWu Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the error case, add_msg() gets called from timer functions, so should
be using GFP_ATOMIC instead of GFP_KERNEL.

Ref: http://bugzilla.kernel.org/show_bug.cgi?id=6659.  Thanks to Christian
Werner <chw@ch-werner.de> for reporting, and for the initial fix.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Mark 3 functions __init.  Saves a little memory.
This makes these functions' calls to AdvWaitEEPCmd() (which is __init)
be clean (i.e., eliminates text -> init -> text call chain).

Fix multiple section mismatch warnings:
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a22) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a4e) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a79) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7aa2) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7abb) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7ae0) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b0c) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b37) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b60) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b79) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7b9e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bca) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bf5) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c1e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c37) and 'AdvExeScsiQueue'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: tossup.
In theory some of these (previously) __init functions could be called
after init, but that problem has not been observed AFAIK.

There were 2 cases of cleanup_module() (module_exit) calling __init
functions (clear_requested_irq() & have_requested_irq()).
These are more serious, but still not observed AFAIK.

Fix sections mismatch:
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x228b) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x22ae) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2501) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x25de) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2698) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2922) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x299e) and 'set_irq'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Make __mcdx_init() __init and static.  Saves a little memory.

Fix section mismatch warning and make the function static while there:
WARNING: drivers/cdrom/mcdx.o - Section mismatch: reference to .init.text: from .text between 'init_module' (at offset 0x8be) and 'mcdx_transfer'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Change 3 functions from __init to __devinit.
Could be an init/probe problem in theory, but not observed, so not
high priority IMO.

Fix section mismatch warnings:
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1aad) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b22) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b31) and 'trident_pci_remove'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

netdev->set_config can be called at any time, so these references
to __initdata would be a real problem.
However, problem has not been observed AFAIK.

Fix section mismatch warnings:
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1b8e) and 'sdla_stats'
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1e76) and 'sdla_stats'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the course of trying to track down a bug where a file mtime was not
being updated correctly, it was discovered that the m/ctime updates were
not quite being handled correctly for ftruncate() calls.

Quoth SUSv3:

open(2):

        If O_TRUNC is set and the file did previously exist, upon
        successful completion, open() shall mark for update the st_ctime
        and st_mtime fields of the file.

truncate(2):

        Upon successful completion, if the file size is changed, this
        function shall mark for update the st_ctime and st_mtime fields
        of the file, and the S_ISUID and S_ISGID bits of the file mode
        may be cleared.

ftruncate(2):

        Upon successful completion, if fildes refers to a regular file,
        the ftruncate() function shall mark for update the st_ctime and
        st_mtime fields of the file and the S_ISUID and S_ISGID bits of
        the file mode may be cleared. If the ftruncate() function is
        unsuccessful, the file is unaffected.

The open(O_TRUNC) and truncate cases were being handled correctly, but the
ftruncate case was being handled like the truncate case.  The semantics of
truncate and ftruncate don't quite match, so ftruncate needs to be handled
slightly differently.

The attached patch addresses this issue for ftruncate(2).

My thanx to Stephen Tweedie and Trond Myklebust for their help in
understanding the situation and semantics.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I'm testing glibc on MIPS64, little-endian, N32, O32 and N64 multilibs.

Among the NPTL test failures seen are some arising from sigsuspend problems
for N32: it blocks the wrong signals, so SIGCANCEL (SIGRTMIN) is blocked
despite glibc's carefully excluding it from sets of signals to block.
Specifically, testing suggests it blocks signal N^32 instead of signal N,
so (in the example tested) blocking SIGUSR1 (17) blocks signal 49 instead.

glibc's sigset_t uses an array of unsigned long, as does the kernel.
In both cases, signal N+1 is represented as
(1UL << (N % (8 * sizeof (unsigned long)))) in word number
(N / (8 * sizeof (unsigned long))).

Thus the N32 glibc uses an array of 32-bit words and the N64 kernel uses an
array of 64-bit words.  For little-endian, the layout is the same, with
signals 1-32 in the first 4 bytes, signals 33-64 in the second, etc.; for
big-endian, userspace has that layout while in the kernel each 8 bytes have
the two halves swapped from the userspace layout.

The N32 sigsuspend syscall uses sigset_from_compat to convert the userspace
sigset to kernel format.  If __COMPAT_ENDIAN_SWAP__ is *not* set, this uses
logic of the form

  set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 )

to convert the userspace sigset to a kernel one.  This looks correct to me
for both big and little endian, given that in userspace compat->sig[1] will
represent signals 33-64, and so will the high 32 bits of set->sig[0] in the
kernel.  If however __COMPAT_ENDIAN_SWAP__ *is* set, as it is for
__MIPSEL__, it uses

  set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );

which seems incorrect for both big and little endian, and would
explain the observed symptoms.

This code is the only use of __COMPAT_ENDIAN_SWAP__, so if incorrect
then that macro serves no purpose, in which case something like the
following patch would seem appropriate to remove it.
Signed-off-by: NJoseph Myers <joseph@codesourcery.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>