Many filesystems need a ->page-mkwrite callout to correctly
set up pages that have been written to by mmap. This is especially
important when mmap is writing into holes as it allows filesystems
to correctly account for and allocate space before the mmap
write is allowed to proceed.
Protection against truncate races is provided by locking the page
and checking to see whether the page mapping is correct and whether
it is beyond EOF so we don't end up allowing allocations beyond
the current EOF or changing EOF as a result of a mmap write.
SGI-PV: 940392
SGI-Modid: 2.6.x-xfs-melb:linux:29146a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (24 commits)
[CIFS] merge conflict in fs/cifs/export.c
[CIFS] Allow disabling CIFS Unix Extensions as mount option
[CIFS] More whitespace/formatting fixes (noticed by checkpatch)
[CIFS] Typo in previous patch
[CIFS] zero_user_page() conversions
[CIFS] use simple_prepare_write to zero page data
[CIFS] Fix build break - inet.h not included when experimental ifdef off
[CIFS] Add support for new POSIX unlink
[CIFS] whitespace/formatting fixes
[CIFS] Fix oops in cifs_create when nfsd server exports cifs mount
[CIFS] whitespace cleanup
[CIFS] Fix packet signatures for NTLMv2 case
[CIFS] more whitespace fixes
[CIFS] more whitespace cleanup
[CIFS] whitespace cleanup
[CIFS] whitespace cleanup
[CIFS] ipv6 support no longer experimental
[CIFS] Mount should fail if server signing off but client mount option requires it
[CIFS] whitespace fixes
[CIFS] Fix sign mount option and sign proc config setting
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/docs-2.6:
zh_CN/HOWTO: update URLs of git trees
Chinese translation of Documentation/stable_api_nonsense.txt
HOWTO: add Chinese translation of Documentation/HOWTO
Documentation: add Japanese translated stable_api_nonsense.txt
HOWTO: add Japanese translation of Documentation/HOWTO
* 'for-linus' of git://linux-nfs.org/~bfields/linux:
locks: fix vfs_test_lock() comment
locks: make posix_test_lock() interface more consistent
nfs: disable leases over NFS
gfs2: stop giving out non-cluster-coherent leases
locks: export setlease to filesystems
locks: provide a file lease method enabling cluster-coherent leases
locks: rename lease functions to reflect locks.c conventions
locks: share more common lease code
locks: clean up lease_alloc()
locks: convert an -EINVAL return to a BUG
leases: minor break_lease() comment clarification
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband: (29 commits)
IB/mthca: Simplify use of size0 in work request posting
IB/mthca: Factor out setting WQE UD segment entries
IB/mthca: Factor out setting WQE remote address and atomic segment entries
IB/mlx4: Factor out setting other WQE segments
IB/mlx4: Factor out setting WQE data segment entries
IB/mthca: Factor out setting WQE data segment entries
IB/mlx4: Return receive queue sizes for userspace QPs from query QP
IB/mlx4: Increase max outstanding RDMA reads as target
RDMA/cma: Remove local write permission from QP access flags
IB/mthca: Use uninitialized_var() for f0
IB/cm: Make internal function cm_get_ack_delay() static
IB/ipath: Remove ipath_get_user_pages_nocopy()
IB/ipath: Make a few functions static
mlx4_core: Reset device when internal error is detected
IB/iser: Make a couple of functions static
IB/mthca: Fix printk format used for firmware version in warning
IB/mthca: Schedule MSI support for removal
IB/ehca: Fix warnings issued by checkpatch.pl
IB/ehca: Restructure ehca_set_pagebuf()
IB/ehca: MR/MW structure refactoring
...
Previously the only way to do this was to umount all mounts to that server,
turn off a proc setting (/proc/fs/cifs/LinuxExtensionsEnabled).
Fixes Samba bugzilla bug number: 4582 (and also 2008)
Signed-off-by: Steve French <sfrench@us.ibm.com>
Thanks to Doug Chapman for pointing out that the comment here is
inconsistent with the function prototype.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Since posix_test_lock(), like fcntl() and ->lock(), indicates absence or
presence of a conflict lock by setting fl_type to, respectively, F_UNLCK
or something other than F_UNLCK, the return value is no longer needed.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
As Peter Staubach says elsewhere
(http://marc.info/?l=linux-kernel&m=118113649526444&w=2):
> The problem is that some file system such as NFSv2 and NFSv3 do
> not have sufficient support to be able to support leases correctly.
> In particular for these two file systems, there is no over the wire
> protocol support.
>
> Currently, these two file systems fail the fcntl(F_SETLEASE) call
> accidentally, due to a reference counting difference. These file
> systems should fail more consciously, with a proper error to
> indicate that the call is invalid for them.
Define an nfs setlease method that just returns -EINVAL.
If someone can demonstrate a real need, perhaps we could reenable
them in the presence of the "nolock" mount option.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Since gfs2 can't prevent conflicting opens or leases on other nodes, we
probably shouldn't allow it to give out leases at all.
Put the newly defined lease operation into use in gfs2 by turning off
lease, unless we're using the "nolock' locking module (in which case all
locking is local anyway).
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Currently leases are only kept locally, so there's no way for a distributed
filesystem to enforce them against multiple clients. We're particularly
interested in the case of nfsd exporting a cluster filesystem, in which
case nfsd needs cluster-coherent leases in order to implement delegations
correctly.
Also add some documentation.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We've been using the convention that vfs_foo is the function that calls
a filesystem-specific foo method if it exists, or falls back on a
generic method if it doesn't; thus vfs_foo is what is called when some
other part of the kernel (normally lockd or nfsd) wants to get a lock,
whereas foo is what filesystems call to use the underlying local
functionality as part of their lock implementation.
So rename setlease to vfs_setlease (which will call a
filesystem-specific setlease after a later patch) and __setlease to
setlease.
Also, vfs_setlease need only be GPL-exported as long as it's only needed
by lockd and nfsd.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Share more code between setlease (used by nfsd) and fcntl.
Also some minor cleanup.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: Christoph Hellwig <hch@infradead.org>
Return the newly allocated structure as the return value instead of
using a struct ** parameter.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There's no point trying to return an error in these cases, which all represent
bugs in the callers.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
clarify that break_lease() checks for presence of any lock, not just leases.
Signed-off-by: David M. Richter <richterd@citi.umich.edu>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Addressing patch from Stefan Richter:
HOWTO: update URLs of git trees
(It will be better if we update this to commit-id later)
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
David Chinner
Linus Torvalds
Steve French
J. Bruce Fields
Marc Eshel
J. Bruce Fields
david m. richter
Li Yang
TripleX