fuse: fix nlink after unlink

Anand Avati reports that the following sequence of system calls fail on a fuse
filesystem:


 	create("filename") => 0
 	link("filename", "linkname") => 0
 	unlink("filename") => 0
 	link("linkname", "filename") => -ENOENT ### BUG ###

vfs_link() fails with ENOENT if i_nlink is zero, this is done to prevent
resurrecting already deleted files.

Fuse clears i_nlink on unlink even if there are other links pointing to the
file.

Reported-by: Anand Avati <avati@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
fuse: O_DIRECT support for files

Implement ->direct_IO() method in aops. The ->direct_IO() method combines
the existing fuse_direct_read/fuse_direct_write methods to implement
O_DIRECT functionality.

Reaching ->direct_IO() in the read path via generic_file_aio_read ensures
proper synchronization with page cache with its existing framework.

Reaching ->direct_IO() in the write path via fuse_file_aio_write is made
to come via generic_file_direct_write() which makes it play nice with
the page cache w.r.t other mmap pages etc.

On files marked 'direct_io' by the filesystem server, IO always follows
the fuse_direct_read/write path. There is no effect of fcntl(O_DIRECT)
and it always succeeds.

On files not marked with 'direct_io' by the filesystem server, the IO
path depends on O_DIRECT flag by the application. This can be passed
at the time of open() as well as via fcntl().

Note that asynchronous O_DIRECT iocb jobs are completed synchronously
always (this has been the case with FUSE even before this patch)

Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
KVM: PMU emulation: GLOBAL_CTRL MSR should be enabled on reset

On reset all MPU counters should be enabled in GLOBAL_CTRL MSR.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
fuse: allow nanosecond granularity

Derrik Pates reports that an utimensat with a NULL argument results in the
current time being sent from the kernel with 1 second granularity.

Reported-by: Derrik Pates <demon@now.ai>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
[S390] drivers/s390/block/dasd_eckd.c: add missing dasd_sfree_request

Extend some error paths to call dasd_sfree_request as done earlier in the
function.  The error-handling code is also moved to the end of the function.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] s390/char/vmur.c: fix memory leak

This patch is used to fix a memory leak issue in s390/char/vmur.c.
A character device instance is allocated by cdev_alloc, the cdev_del
will not free that space if cdev_init is applied before.

Signed-off-by: Dennis Chen <dennis1.chen@amd.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] kernel: Use local_irq_save() for memcpy_real()

Currently in the memcpy_real() function interrupts are disabled with
__arch_local_irq_stnsm(). In order to notify lockdep that interrupts
are disabled, with this patch local_irq_save() is used instead. The
function __arch_local_irq_stnsm() is still used for switching to
real mode.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] fix tlb flushing for page table pages

Git commit 36409f6353fc2d7b6516e631415f938eadd92ffa "use generic RCU
page-table freeing code" introduced a tlb flushing bug. Partially revert
the above git commit and go back to s390 specific page table flush code.

For s390 the TLB can contain three types of entries, "normal" TLB
page-table entries, TLB combined region-and-segment-table (CRST) entries
and real-space entries. Linux does not use real-space entries which
leaves normal TLB entries and CRST entries. The CRST entries are
intermediate steps in the page-table translation called translation paths.
For example a 4K page access in a three-level page table setup will
create two CRST TLB entries and one page-table TLB entry. The advantage
of that approach is that a page access next to the previous one can reuse
the CRST entries and needs just a single read from memory to create the
page-table TLB entry. The disadvantage is that the TLB flushing rules are
more complicated, before any page-table may be freed the TLB needs to be
flushed.

In short: the generic RCU page-table freeing code is incorrect for the
CRST entries, in particular the check for mm_users < 2 is troublesome.

This is applicable to 3.0+ kernels.

Cc: <stable@vger.kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] update default configuration

Add TASKSTATS options, enable CRASH_DUMP, and regenerate defconfig
file with "make savedefconfig".

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] irq: simple coding style change

Use braces for if/else/list_for_each_entry bodies if the body consists
of more than a single line. Otherwise I get confused and check if there
is something broken whenever I see these code snippets.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] cpum_cf: get rid of compile warnings

Fix these:

arch/s390/kernel/perf_cpum_cf.c:180:3: warning: format '%lx'
   expects argument of type 'long unsigned int',
   but argument 2 has type 'int' [-Wformat]
arch/s390/kernel/perf_cpum_cf.c: In function 'cpumf_pmu_disable':
arch/s390/kernel/perf_cpum_cf.c:205:3: warning: format '%lx'
   expects argument of type 'long unsigned int',
   but argument 2 has type 'int' [-Wformat]

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] Fix stfle() lowcore protection problem

The stfle() function writes into lowcore memory when stfl_fac_list
is initialized with "S390_lowcore.stfl_fac_list = 0". For older
compilers this triggers a lowcore exception. With newer compilers
and "-OXX" compile option the bug does not show up because
the "S390_lowcore.stfl_fac_list" initialization is removed by the
compiler. The reason for thatis the incorrect "=m"
(S390_lowcore.stfl_fac_list) constraint in the stfl inline assembly.

The following shows the disassembly of the stfle() optimized code
that is inlined in the lgr_info_get() function:

000000000011325c <lgr_info_get>:
  11325c:       eb 9f f0 60 00 24       stmg    %r9,%r15,96(%r15)
  113262:       c0 d0 00 29 0e 47       larl    %r13,634ef0 <servi..>
  113268:       a7 f1 3f c0             tml     %r15,16320
  11326c:       b9 04 00 ef             lgr     %r14,%r15
  113270:       a7 84 00 01             je      113272 <lgr_info_g..>
  113274:       a7 fb ff c0             aghi    %r15,-64
  113278:       b9 04 00 c2             lgr     %r12,%r2
  11327c:       a7 29 00 01             lghi    %r2,1
  113280:       e3 e0 f0 98 00 24       stg     %r14,152(%r15)
  113286:       d7 97 c0 00 c0 00       xc      0(152,%r12),0(%r12)
  11328c:       c0 e5 00 28 db 4c       brasl   %r14,62e924 <add_e..>
  113292:       b2 b1 00 00             stfl    0

To fix the problem we now clear the S390_lowcore.stfl_fac_list at
startup in "head.S" for all machine types before lowcore protection
is enabled.

In addition to that the "=m" constraint is replaced by "+m".

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[S390] Fix compile error in swab.h

The inline assembly in__arch_swab16p causes compile errors of the form:

*error*: *invalid* '*asm*': operand number missing after %-*letter*

The assembly uses the %O<n>/%R<n> notation but the first operand misses
the operand number, it needs to be "%O1" instead of "%O".

Reported-by: Gil Peleg <gilpeleg@servframe.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
KVM: unmap pages from the iommu when slots are removed

We've been adding new mappings, but not destroying old mappings.
This can lead to a page leak as pages are pinned using
get_user_pages, but only unpinned with put_page if they still
exist in the memslots list on vm shutdown.  A memslot that is
destroyed while an iommu domain is enabled for the guest will
therefore result in an elevated page reference count that is
never cleared.

Additionally, without this fix, the iommu is only programmed
with the first translation for a gpa.  This can result in
peer-to-peer errors if a mapping is destroyed and replaced by a
new mapping at the same gpa as the iommu will still be pointing
to the original, pinned memory address.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cleanup handling of NULL value passed for a mount option

Allow blank user= and ip= mount option. Also clean up redundant
checks for NULL values since the token parser will not actually
match mount options with NULL values unless explicitly specified.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Chris Clayton <chris2553@googlemail.com>
Acked-by: Jeff Layton <jlayton@samba.org>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
fuse: use flexible array in fuse.h

Use the ISO C standard compliant form instead of the gcc extension in the
interface definition.

Reported-by: Shachar Sharon <ssnail@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
ata_piix: IDE-mode SATA patch for Intel DH89xxCC DeviceIDs

This patch adds the IDE-mode SATA DeviceIDs for the Intel DH89xxCC PCH.

Signed-off-by: Seth Heasley <seth.heasley@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
sata_mv: silence an uninitialized variable warning

Gcc version 4.6.2-12 complains that if we can't find the "nr-ports"
property in of_property_read_u32_array() then "n_ports" is used
uninitialized.  Let's set it to zero in that case.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
libata: make ata_print_id atomic

This variable is incremented from multiple contexts (module_init via
libata-lldds and the libsas discovery thread).  Make it atomic to head
off any chance of libsas and libata creating duplicate ids.

Acked-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
nfsd: fix b0rken error value for setattr on read-only mount

..._want_write() returns -EROFS on failure, _not_ an NFS error value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>