* 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
debugobjects: Add hint for better object identification
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits)
tidy the trailing symlinks traversal up
Turn resolution of trailing symlinks iterative everywhere
simplify link_path_walk() tail
Make trailing symlink resolution in path_lookupat() iterative
update nd->inode in __do_follow_link() instead of after do_follow_link()
pull handling of one pathname component into a helper
fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
readlinkat(), fchownat() and fstatat() with empty relative pathnames
Allow O_PATH for symlinks
New kind of open files - "location only".
ext4: Copy fs UUID to superblock
ext3: Copy fs UUID to superblock.
vfs: Export file system uuid via /proc/<pid>/mountinfo
unistd.h: Add new syscalls numbers to asm-generic
x86: Add new syscalls for x86_64
x86: Add new syscalls for x86_32
fs: Remove i_nlink check from file system link callback
fs: Don't allow to create hardlink for deleted file
vfs: Add open by file handle support
...
The new vfs locking scheme introduced in 2.6.38 breaks NFS sillyrename
because the latter relies on being able to determine the parent
directory of the dentry in the ->iput() callback in order to send the
appropriate unlink rpc call.
Looking at the code that cares about races with dput(), there doesn't
seem to be anything that specifically uses d_parent as a test for
whether or not there is a race:
- __d_lookup_rcu(), __d_lookup() all test for d_hashed() after d_parent
- shrink_dcache_for_umount() is safe since nothing else can rearrange
the dentries in that super block.
- have_submount(), select_parent() and d_genocide() can test for a
deletion if we set the DCACHE_DISCONNECTED flag when the dentry
is removed from the parent's d_subdirs list.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org (2.6.38, needs commit c826cb7dfc "dcache.c:
create helper function for duplicated functionality" )
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This creates a helper function for he "try to ascend into the parent
directory" case, which was written out in triplicate before. With all
the locking and subtle sequence number stuff, we really don't want to
duplicate that kind of code.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pull the handling of current->total_link_count into
__do_follow_link()
* put the common "do ->put_link() if needed and path_put() the link"
stuff into a helper (put_link(nd, link, cookie))
* rename __do_follow_link() to follow_link(), while we are at it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The last remaining place (resolution of nested symlink) converted
to the loop of the same kind we have in path_lookupat() and
path_openat().
Note that we still *do* have a recursion in pathname resolution;
can't avoid it, really. However, it's strictly for nested symlinks
now - i.e. ones in the middle of a pathname.
link_path_walk() has lost the tail now - it always walks everything
except the last component.
do_follow_link() renamed to nested_symlink() and moved down.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that link_path_walk() is called without LOOKUP_PARENT
only from do_follow_link(), we can simplify the checks in
last component handling. First of all, checking if we'd
arrived to a directory is not needed - the caller will check
it anyway. And LOOKUP_FOLLOW is guaranteed to be there,
since we only get to that place with nd->depth > 0.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new helper: walk_component(). Handles everything except symlinks;
returns negative on error, 0 on success and 1 on symlinks we decided
to follow. Drops out of RCU mode on such symlinks.
link_path_walk() and do_last() switched to using that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We don't want to allow creation of private hardlinks by different application
using the fd passed to them via SCM_RIGHTS. So limit the null relative name
usage in linkat syscall to CAP_DAC_READ_SEARCH
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Newer compilers (gcc 4.6) complains about:
return ret < 0 ?: 0;
For the following reason:
util/probe-finder.c: In function ‘probe_point_lazy_walker’:
util/probe-finder.c:1331:18: error: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Werror=parentheses]
And indeed the return value is a somewhat obscure (but correct) value
of 'true', so return 'ret' instead - this is cleaner and unconfuses
GCC as well.
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
xen: suspend: remove xen_hvm_suspend
xen: suspend: pull pre/post suspend hooks out into suspend_info
xen: suspend: move arch specific pre/post suspend hooks into generic hooks
xen: suspend: refactor non-arch specific pre/post suspend hooks
xen: suspend: add "arch" to pre/post suspend hooks
xen: suspend: pass extra hypercall argument via suspend_info struct
xen: suspend: refactor cancellation flag into a structure
xen: suspend: use HYPERVISOR_suspend for PVHVM case instead of open coding
xen: switch to new schedop hypercall by default.
xen: use new schedop interface for suspend
xen: do not respond to unknown xenstore control requests
xen: fix compile issue if XEN is enabled but XEN_PVHVM is disabled
xen: PV on HVM: support PV spinlocks and IPIs
xen: make the ballon driver work for hvm domains
xen-blkfront: handle Xen major numbers other than XENVBD
xen: do not use xen_info on HVM, set pv_info name to "Xen HVM"
xen: no need to delay xen_setup_shutdown_event for hvm guests anymore
rdma_destroy_id currently uses the global rdma cm 'lock' to test if an
rdma_cm_id has been bound to a device. This prevents an active
address resolution callback handler from assigning a device to the
rdma_cm_id after rdma_destroy_id checks for one.
Instead, we can replace the use of the global lock around the check to
the rdma_cm_id device pointer by setting the id state to destroying,
then flushing all active callbacks. The latter is accomplished by
acquiring and releasing the handler_mutex. Any active handler will
complete first, and any newly scheduled handlers will find the
rdma_cm_id in an invalid state.
In addition to optimizing the current locking scheme, the use of the
rdma_cm_id mutex is a more intuitive synchronization mechanism than
that of the global lock. These changes are based on feedback from
Doug Ledford <dledford@redhat.com> while he was trying to debug a
crash in the rdma cm destroy path.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This problem was reported by Moni Shoua <monis@mellanox.com> and Amir
Vadai <amirv@mellanox.com>:
When destroying a cm_id from a context of a work queue and if
the lap_state of this cm_id is IB_CM_LAP_SENT, we need to
release the reference of this id that was taken upon the send
of the LAP message. Otherwise, if the expected APR message
gets lost, it is only after a long time that the reference
will be released, while during that the work handler thread is
not available to process other things.
It turns out that we need to cancel any pending LAP messages whenever
we transition out of the IB_CM_ESTABLISH state. This occurs when
disconnecting - either sending or receiving a DREQ. It can also
happen in a corner case where we receive a REJ message after sending
an RTU, followed by a LAP. Add checks and cancel any outstanding LAP
messages in these three cases.
Canceling the LAP when sending a DREQ fixes the destroy problem
reported by Moni. When a cm_id is destroyed in the IB_CM_ESTABLISHED
state, it sends a DREQ to the remote side to notify the peer that the
connection is going away.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
When processing a SIDR REQ, the ib_cm allocates a new cm_id. The
refcount of the cm_id is initialized to 1. However, cm_process_work
will decrement the refcount after invoking all callbacks. The result
is that the cm_id will end up with refcount set to 0 by the end of the
sidr req handler.
If a user tries to destroy the cm_id, the destruction will proceed,
under the incorrect assumption that no other threads are referencing
the cm_id. This can lead to a crash when the cm callback thread tries
to access the cm_id.
This problem was noticed as part of a larger investigation with kernel
crashes in the rdma_cm when running on a real time OS.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
* 'stable/ia64' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: ia64 build broken due to "xen: switch to new schedop hypercall by default."
* 'stable/blkfront-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: Union the blkif_request request specific fields
* 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: annotate functions which only call into __init at start of day
xen p2m: annotate variable which appears unused
xen: events: mark cpu_evtchn_mask_p as __refdata
* 'stable/irq.cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: events: remove dom0 specific xen_create_msi_irq
xen: events: use xen_bind_pirq_msi_to_irq from xen_create_msi_irq
xen: events: push set_irq_msi down into xen_create_msi_irq
xen: events: update pirq_to_irq in xen_create_msi_irq
xen: events: refactor xen_create_msi_irq slightly
xen: events: separate MSI PIRQ allocation from PIRQ binding to IRQ
xen: events: assume PHYSDEVOP_get_free_pirq exists
xen: pci: collapse apic_register_gsi_xen_hvm and xen_hvm_register_pirq
xen: events: return irq from xen_allocate_pirq_msi
xen: events: drop XEN_ALLOC_IRQ flag to xen_allocate_pirq_msi
xen: events: do not leak IRQ from xen_allocate_pirq_msi when no pirq available.
xen: pci: only define xen_initdom_setup_msi_irqs if CONFIG_XEN_DOM0
* 'stable/irq.rework' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/irq: Cleanup up the pirq_to_irq for DomU PV PCI passthrough guests as well.
xen: Use IRQF_FORCE_RESUME
xen/timer: Missing IRQF_NO_SUSPEND in timer code broke suspend.
xen: Fix compile error introduced by "switch to new irq_chip functions"
xen: Switch to new irq_chip functions
xen: Remove stale irq_chip.end
xen: events: do not free legacy IRQs
xen: events: allocate GSIs and dynamic IRQs from separate IRQ ranges.
xen: events: add xen_allocate_irq_{dynamic, gsi} and xen_free_irq
xen:events: move find_unbound_irq inside CONFIG_PCI_MSI
xen: handled remapped IRQs when enabling a pcifront PCI device.
genirq: Add IRQF_FORCE_RESUME
* 'stable/pcifront-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
pci/xen: When free-ing MSI-X/MSI irq->desc also use generic code.
pci/xen: Cleanup: convert int** to int[]
pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq
xen-pcifront: Sanity check the MSI/MSI-X values
xen-pcifront: don't use flush_scheduled_work()
* 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set..
xen/m2p: No need to catch exceptions when we know that there is no RAM
xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set.
xen/debugfs: Add 'p2m' file for printing out the P2M layout.
xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.
xen/mmu: WARN_ON when racing to swap middle leaf.
xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN.
xen/mmu: Add the notion of identity (1-1) mapping.
xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.
* 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
Doug Ledford and Red Hat reported a crash when running the rdma_cm on
a real-time OS. The crash has the following call trace:
cm_process_work
cma_req_handler
cma_disable_callback
rdma_create_id
kzalloc
init_completion
cma_get_net_info
cma_save_net_info
cma_any_addr
cma_zero_addr
rdma_translate_ip
rdma_copy_addr
cma_acquire_dev
rdma_addr_get_sgid
ib_find_cached_gid
cma_attach_to_dev
ucma_event_handler
kzalloc
ib_copy_ah_attr_to_user
cma_comp
[ preempted ]
cma_write
copy_from_user
ucma_destroy_id
copy_from_user
_ucma_find_context
ucma_put_ctx
ucma_free_ctx
rdma_destroy_id
cma_exch
cma_cancel_operation
rdma_node_get_transport
rt_mutex_slowunlock
bad_area_nosemaphore
oops_enter
They were able to reproduce the crash multiple times with the
following details:
Crash seems to always happen on the:
mutex_unlock(&conn_id->handler_mutex);
as conn_id looks to have been freed during this code path.
An examination of the code shows that a race exists in the request
handlers. When a new connection request is received, the rdma_cm
allocates a new connection identifier. This identifier has a single
reference count on it. If a user calls rdma_destroy_id() from another
thread after receiving a callback, rdma_destroy_id will proceed to
destroy the id and free the associated memory. However, the request
handlers may still be in the process of running. When control returns
to the request handlers, they can attempt to access the newly created
identifiers.
Fix this by holding a reference on the newly created rdma_cm_id until
the request handler is through accessing it.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Intel Archiecture Software Developer's Manual section 7.1.3 specifies that a
core serializing instruction such as "cpuid" should be executed on _each_ core
before the new instruction is made visible.
Failure to do so can lead to unspecified behavior (Intel XMC erratas include
General Protection Fault in the list), so we should avoid this at all cost.
This problem can affect modified code executed by interrupt handlers after
interrupt are re-enabled at the end of stop_machine, because no core serializing
instruction is executed between the code modification and the moment interrupts
are reenabled.
Because stop_machine_text_poke performs the text modification from the first CPU
decrementing stop_machine_first, modified code executed in thread context is
also affected by this problem. To explain why, we have to split the CPUs in two
categories: the CPU that initiates the text modification (calls text_poke_smp)
and all the others. The scheduler, executed on all other CPUs after
stop_machine, issues an "iret" core serializing instruction, and therefore
handles core serialization for all these CPUs. However, the text modification
initiator can continue its execution on the same thread and access the modified
text without any scheduler call. Given that the CPU that initiates the code
modification is not guaranteed to be the one actually performing the code
modification, it falls into the XMC errata.
Q: Isn't this executed from an IPI handler, which will return with IRET (a
serializing instruction) anyway?
A: No, now stop_machine uses per-cpu workqueue, so that handler will be
executed from worker threads. There is no iret anymore.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
LKML-Reference: <20110303160137.GB1590@Krystal>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: <stable@kernel.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Changes to make sure writeback fid is owned by root
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
change file attribute can result in making the file readonly.
So flush the dirty pages before that.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We need to call vmtruncate before 9p setattr operation, otherwise we
could write back some dirty pages between setattr with ATTR_SIZE and vmtruncate
causing some truncated pages to be written back to server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
With caching enabled, we need to make sure we don't
update inode->i_size via stat2inode because we could
have dirty data which is not yet written to the server
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This is similar to what ceph, ocfs2 and nfs does
http://kerneltrap.org/mailarchive/linux-fsdevel/2008/4/18/1498534
May be we should get vfs fixed
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
One successfull directory operation we would have changed directory
inode attribute. So mark them invalid
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We need to revalidate . and .. entries also
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
rename, unlink and setattr can result in update of inode attribute.
So mark the cached copy invalid
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
With cached mode some of the file system operation result
in updating inode attributes (ctime). Add support for
marking inode attribute invalid in such cases so that
we fetch the updated inode attribute on dentry revalidation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We want to immediately drop the inode in non cached mode
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Only update inode i_size when we write towards end of file.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We want to enable readahead in cached mode
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Switch to the fscache code to v9fs_inode. We will later use
v9fs_inode in cache=loose mode to track the inode cache
validity timeout. Ie if we find an inode in cache older
that a specific jiffie range we will consider it stale
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
simple_getattr does set stat.st_blocks to a value
derived from nrpages. That is not correct with 9p
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We didn't add the inode to inode hash in 9p. We need to do that
to get sync to work, otherwise __mark_inode_dirty will not
add the inode to super block's dirty list.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
FIXME!! what about dotu ?
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We should not mark file system synchronous if mounted cache=* option
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Update the comment to indicate that we don't want to cache
negative dentries.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
We can now support writeable mmaps.
Based on the original patch from Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Linus Torvalds