Like flock locks, leases are owned by the file description. Now that the
i_have_this_lease check in __break_lease is gone, we don't actually use
the fl_owner for leases for anything. So, it's now safe to set this more
appropriately to the same value as the fl_file.
While we're at it, fix up the comments over the fl_owner_t definition
since they're rather out of date.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Christoph suggests:
"Add a return value to lm_break so that the lock manager can tell the
core code "you can delete this lease right now". That gets rid of
the games with the timeout which require all kinds of race avoidance
code in the users."
Do that here and have the nfsd lease break routine use it when it detects
that there was a race between setting up the lease and it being broken.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
There was only one place where we still could free a file_lock while
holding the i_lock -- lease_modify. Add a new list_head argument to the
lm_change operation, pass in a private list when calling it, and fix
those callers to dispose of the list once the lock has been dropped.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
...and move the fasync setup into it for fcntl lease calls. At the same
time, change the semantics of how the file_lock double-pointer is
handled. Up until now, on a successful lease return you got a pointer to
the lock on the list. This is bad, since that pointer can no longer be
relied on as valid once the inode->i_lock has been released.
Change the code to instead just zero out the pointer if the lease we
passed in ended up being used. Then the callers can just check to see
if it's NULL after the call and free it if it isn't.
The priv argument has the same semantics. The lm_setup function can
zero the pointer out to signal to the caller that it should not be
freed after the function returns.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock. To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.
We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Testing xmit_more support with netperf and connected UDP sockets,
I found strange dst refcount false sharing.
Current handling of IFF_XMIT_DST_RELEASE is not optimal.
Dropping dst in validate_xmit_skb() is certainly too late in case
packet was queued by cpu X but dequeued by cpu Y
The logical point to take care of drop/force is in __dev_queue_xmit()
before even taking qdisc lock.
As Julian Anastasov pointed out, need for skb_dst() might come from some
packet schedulers or classifiers.
This patch adds new helper to cleanly express needs of various drivers
or qdiscs/classifiers.
Drivers that need skb_dst() in their ndo_start_xmit() should call
following helper in their setup instead of the prior :
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
->
netif_keep_dst(dev);
Instead of using a single bit, we use two bits, one being
eventually rebuilt in bonding/team drivers.
The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
rebuilt in bonding/team. Eventually, we could add something
smarter later.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adjust fixed_phy_register() to return struct phy_device *, so that
it becomes easy to use fixed PHYs without device tree support:
phydev = fixed_phy_register(PHY_POLL, &fixed_phy_status, NULL);
fixed_phy_set_link_update(phydev, fixed_phy_link_update);
phy_connect_direct(netdev, phydev, handler_fn, phy_interface);
This change is a prerequisite for modifying bcmgenet driver to work
without a device tree on Broadcom's MIPS-based 7xxx platforms.
Signed-off-by: Petri Gynther <pgynther@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
X-Powers AXP288 is a customized PMIC for Intel Baytrail-CR platforms. Similar
to AXP202/209, AXP288 comes with USB charger, more LDO and BUCK channels, and
AD converters. It also provides extended status and interrupt reporting
capabilities than the devices currently supported in axp20x.c.
In addition to feature extension, this patch also adds ACPI binding for
enumeration.
This consolidated driver should support more X-Powers' PMICs in both device
tree and ACPI enumerated platforms.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
* pm-cpufreq:
cpufreq: cpufreq-dt: fix potential double put of cpu OF node
cpufreq: cpu0: rename driver and internals to 'cpufreq_dt'
cpufreq: ppc-corenet: remove duplicate update of cpu_data
cpufreq: Replace strnicmp with strncasecmp
cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec
cpufreq: powernv: Set the pstate of the last hotplugged out cpu in policy->cpus to minimum
cpufreq: Allow stop CPU callback to be used by all cpufreq drivers
cpufreq: cpu0: Make allocate_resources() work for any CPU
cpufreq: cpu0: try regulators with name "cpu-supply"
cpufreq: cpu0: Move per-cluster initialization code to ->init()
cpufreq: cpu0: use dev_{err|warn|dbg} instead of pr_{err|warn|debug}
cpufreq: cpu0: print relevant error when we defer probe
cpufreq: cpu0: don't validate clock on clk_put()
cpufreq: cpu0: Update Module Author
cpufreq: Add support for per-policy driver data
Some TSO engines might have a too heavy setup cost, that impacts
performance on hosts sending small bursts (2 MSS per packet).
This patch adds a device gso_min_segs, allowing drivers to set
a minimum segment size for TSO packets, according to the NIC
performance.
Tested on a mlx4 NIC, this allows to get a ~110% increase of
throughput when sending 2 MSS per packet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of having users of the ChromeOS EC call the interface-specific
cmd_xfer() callback directly, introduce a central cros_ec_cmd_xfer()
to use instead. This will allow us to put all the locking and retry
logic in one place instead of duplicating it across the different
drivers.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
- Remove unused variable ring->poll_cnt
- No need to set some fields if using blueflame
- Add missing const's
- Use unlikely
- Remove unneeded new line
- Make some comments more precise
- struct mlx4_bf @offset field reduced to unsigned int to save space
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
John W. Linville says:
====================
pull request: wireless-next 2014-10-03
Please pull tihs batch of updates intended for the 3.18 stream!
For the iwlwifi bits, Emmanuel says:
"I have here a few things that depend on the latest mac80211's changes:
RRM, TPC, Quiet Period etc... Eyal keeps improving our rate control
and we have a new device ID. This last patch should probably have
gone to wireless.git, but at that stage, I preferred to send it to
-next and CC stable."
For (most of) the Atheros bits, Kalle says:
"The only new feature is testmode support from me. Ben added a new method
to crash the firmware with an assert for debug purposes. As usual, we
have lots of smaller fixes from Michal. Matteo fixed a Kconfig
dependency with debugfs. I fixed some warnings recently added to
checkpatch."
For the NFC bits, Samuel says:
"We've had major updates for TI and ST Microelectronics drivers, and a
few NCI related changes.
For TI's trf7970a driver:
- Target mode support for trf7970a
- Suspend/resume support for trf7970a
- DT properties additions to handle different quirks
- A bunch of fixes for smartphone IOP related issues
For ST Microelectronics' ST21NFCA and ST21NFCB drivers:
- ISO15693 support for st21nfcb
- checkpatch and sparse related warning fixes
- Code cleanups and a few minor fixes
Finally, Marvell added ISO15693 support to the NCI stack, together with a
couple of NCI fixes."
For the Bluetooth bits, Johan says:
"This 3.18 pull request replaces the one I did on Monday ("bluetooth-next
2014-09-22", which hasn't been pulled yet). The additions since the last
request are:
- SCO connection fix for devices not supporting eSCO
- Cleanups regarding the SCO establishment logic
- Remove unnecessary return value from logging functions
- Header compression fix for 6lowpan
- Cleanups to the ieee802154/mrf24j40 driver
Here's a copy from previous request that this one replaces:
'
Here are some more patches for 3.18. They include various fixes to the
btusb HCI driver, a fix for LE SMP, as well as adding Jukka to the
MAINTAINERS file for generic 6LoWPAN (as requested by Alexander Aring).
I've held on to this pull request a bit since we were waiting for a SCO
related fix to get sorted out first. However, since the merge window is
getting closer I decided not to wait for it. If we do get the fix sorted
out there'll probably be a second small pull request later this week.
'"
And,
"Unless 3.17 gets delayed this will probably be our last -next pull request for
3.18. We've got:
- New Marvell hardware supportr
- Multicast support for 6lowpan
- Several of 6lowpan fixes & cleanups
- Fix for a (false-positive) lockdep warning in L2CAP
- Minor btusb cleanup"
On top of all that comes the usual sort of updates to ath5k, ath9k,
ath10k, brcmfmac, mwifiex, and wil6210. This time around there are
also a number of rtlwifi updates to enable some new hardware and
to reconcile the in-kernel drivers with some newer releases of the
Realtek vendor drivers. Also of note is some device tree work for
the bcma bus.
Please let me know if there are problems!
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
SKB_FCLONE_UNAVAILABLE has overloaded meaning depending on type of skb.
1: If skb is allocated from head_cache, it indicates fclone is not available.
2: If skb is a companion fclone skb (allocated from fclone_cache), it indicates
it is available to be used.
To avoid confusion for case 2 above, this patch replaces
SKB_FCLONE_UNAVAILABLE with SKB_FCLONE_FREE where appropriate. For fclone
companion skbs, this indicates it is free for use.
SKB_FCLONE_UNAVAILABLE will now simply indicate skb is from head_cache and
cannot / will not have a companion fclone.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce support for dynamic device tree resolution.
Using it, it is possible to prepare a device tree that's
been loaded on runtime to be modified and inserted at the kernel
live tree.
Export of of_resolve and bug fix of double free by
Guenter Roeck <groeck@juniper.net>
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[grant.likely: Don't need to select CONFIG_OF_DYNAMIC and CONFIG_OF_DEVICE]
[grant.likely: Don't need to depend on OF or !SPARC]
[grant.likely: Factor out duplicate code blocks into single function]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
This patch change structure name and related variables names.
Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This patch removes fou[46]_gro_receive and fou[46]_gro_complete
functions. The v4 or v6 variants were chosen for the UDP offloads
based on the address family of the socket this is not necessary
or correct. Alternatively, this patch adds is_ipv6 to napi_gro_skb.
This is set in udp6_gro_receive and unset in udp4_gro_receive. In
fou_gro_receive the value is used to select the correct inet_offloads
for the protocol of the outer IP header.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Freescale updates from Scott (27 commits):
"Highlights include DMA32 zone support (SATA, USB, etc now works on 64-bit
FSL kernels), MSI changes, 8xx optimizations and cleanup, t104x board
support, and PrPMC PCI enumeration."
This patch puts a common part as the first field of mlx5_core_qp. This field is
used to identify which resource generated an event. This is required since upcoming
new resource types such as DC targets are allocated for the same numerical space
as regular QPs and may generate the same events. By searching the resource in the
same table we can then look at the common field to identify the resource.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transform device capabilities related commands to use set/get macros to
manipulate command mailboxes.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an auto generated header file that describes hardware registers along with
set of macros that set/get values. The macros do static checks to avoid
overflow, handle endianess, and overall provide a clean way to code commands.
Currently the header file is small and we will add structs as we make use of
the macros.
A few commands were removed from the commands enum since they are not supported
currently and will be added when support is available.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rearrange struct mlx5_caps so it has a "gen" field to represent the current
capabilities configured for the device. Max capabilities can also be queried
from the device. Also update capabilities struct to contain more fields as per
the latest revision if firmware specification.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Validation of skb can be pretty expensive :
GSO segmentation and/or checksum computations.
We can do this without holding qdisc lock, so that other cpus
can queue additional packets.
Trick is that requeued packets were already validated, so we carry
a boolean so that sch_direct_xmit() can validate a fresh skb list,
or directly use an old one.
Tested on 40Gb NIC (8 TX queues) and 200 concurrent flows, 48 threads
host.
Turning TSO on or off had no effect on throughput, only few more cpu
cycles. Lock contention on qdisc lock disappeared.
Same if disabling TX checksum offload.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The return value is not used by callers of these functions
so change the functions to return void.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Users of bio_clone_fast() do not want bios with their own bvecs.
Allocating a bvec mempool as part of the bioset intended for such users
is a waste of memory.
bioset_create_nobvec() creates a bioset that doesn't have the bvec
mempool.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
There are some circumstances that call for trying to write an EFI
variable in a non-blocking way. One such scenario is when writing pstore
data in efi_pstore_write() via the pstore_dump() kdump callback.
Now that we have an EFI runtime spinlock we need a way of aborting if
there is contention instead of spinning, since when writing pstore data
from the kdump callback, the runtime lock may already be held by the CPU
that's running the callback if we crashed in the middle of an EFI
variable operation.
The situation is sufficiently special that a new EFI variable operation
is warranted.
Introduce ->set_variable_nonblocking() for this use case. It is an
optional EFI backend operation, and need only be implemented by those
backends that usually acquire locks to serialize access to EFI
variables, as is the case for virt_efi_set_variable() where we now grab
the EFI runtime spinlock.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
At the moment, there are three architectures debug-printing the EFI memory
map at initialization: x86, ia64, and arm64. They all use different format
strings, plus the EFI memory type and the EFI memory attributes are
similarly hard to decode for a human reader.
Introduce a helper __init function that formats the memory type and the
memory attributes in a unified way, to a user-provided character buffer.
The array "memory_type_name" is copied from the arm64 code, temporarily
duplicating it. The (otherwise optional) braces around each string literal
in the initializer list are dropped in order to match the kernel coding
style more closely. The element size is tightened from 32 to 20 bytes
(maximum actual string length + 1) so that we can derive the field width
from the element size.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[ Dropped useless 'register' keyword, which compiler will ignore ]
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Add the following macro from the UEFI spec, for completeness:
EFI_MEMORY_UCE Memory cacheability attribute: The memory region
supports being configured as not cacheable, exported,
and supports the "fetch and add" semaphore mechanism.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
There should be a generic function to parse params like a=b,c
Adding parse_option_str in lib/cmdline.c which will return true
if there's specified option set in the params.
Also updated efi=old_map parsing code to use the new function
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
noefi param can be used for arches other than X86 later, thus move it
out of x86 platform code.
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We need a way to customize the behaviour of the EFI boot stub, in
particular, we need a way to disable the "chunking" workaround, used
when reading files from the EFI System Partition.
One of my machines doesn't cope well when reading files in 1MB chunks to
a buffer above the 4GB mark - it appears that the "chunking" bug
workaround triggers another firmware bug. This was only discovered with
commit 4bf7111f50 ("x86/efi: Support initrd loaded above 4G"), and
that commit is perfectly valid. The symptom I observed was a corrupt
initrd rather than any kind of crash.
efi= is now used to specify EFI parameters in two very different
execution environments, the EFI boot stub and during kernel boot.
There is also a slight performance optimization by enabling efi=nochunk,
but that's offset by the fact that you're more likely to run into
firmware issues, at least on x86. This is the rationale behind leaving
the workaround enabled by default.
Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're
using the current value of 1MB.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
The "cpu_data" are defined for some archs and thus conflicting with the
"cpu_data" member in the struct gpd_cpu_data. This causes a compiler
error for those archs.
Let's fix it by rename the member to cpuidle_data. In this context it
also seems appropriate to rename the struct to gpd_cpuidle_data to
better reflect its use.
Fixes: f48c767ce8 (PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h)
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a quirk for a host controller that always sets
a Transfer Complete interrupt status for the stop
command even when a busy response is not indicated.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
In order to prevent a O(n) search of the filesystem to link up its uio
node with its target configuration, TCMU needs to know the minor number
that UIO assigned. Expose the definition of this struct so TCMU can
access this field.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Commit f0bab73cb5 ("locking/lockdep: Restrict the use of recursive
read_lock() with qrwlock") changed lockdep to try and conform to the
qrwlock semantics which differ from the traditional rwlock semantics.
In particular qrwlock is fair outside of interrupt context, but in
interrupt context readers will ignore all fairness.
The problem modeling this is that read and write side have different
lock state (interrupts) semantics but we only have a single
representation of these. Therefore lockdep will get confused, thinking
the lock can cause interrupt lock inversions.
So revert it for now; the old rwlock semantics were already imperfectly
modeled and the qrwlock extra won't fit either.
If we want to properly fix this, I think we need to resurrect the work
by Gautham did a few years ago that split the read and write state of
locks:
http://lwn.net/Articles/332801/
FWIW the locking selftest that would've failed (and was reported by
Borislav earlier) is something like:
RL(X1); /* IRQ-ON */
LOCK(A);
UNLOCK(A);
RU(X1);
IRQ_ENTER();
RL(X1); /* IN-IRQ */
RU(X1);
IRQ_EXIT();
At which point it would report that because A is an IRQ-unsafe lock we
can suffer the following inversion:
CPU0 CPU1
lock(A)
lock(X1)
lock(A)
<IRQ>
lock(X1)
And this is 'wrong' because X1 can recurse (assuming the above lock are
in fact read-lock) but lockdep doesn't know about this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: ego@linux.vnet.ibm.com
Cc: bp@alien8.de
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140930132600.GA7444@worktop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Conflicts:
drivers/net/usb/r8152.c
net/netfilter/nfnetlink.c
Both r8152 and nfnetlink conflicts were simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 98e90de99a
"mmc: host: switch OF parser to use gpio descriptors"
switched the semantic behaviour of card detect and read
only flags such that the inversion capability flag would
only be set if inversion was explicitly specified in the
device tree, in the hopes that no-one was using double
inversion.
It turns out that the XOR:ing between the explicit
inversion was indeed in use, so we need to restore the
old semantics where both ways of inversion are checked
and the end result XOR:ed.
Reported-by: Javier Martinez Canillas <javier@dowhile0.org>
Tested-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This event closes an important gap in the bus notifiers.
There is already the BUS_NOTIFY_DEL_DEVICE event, but that
is sent when the device is still bound to its device driver.
This is too early for the IOMMU code to destroy any mappings
for the device, as they might still be in use by the driver.
The new BUS_NOTIFY_REMOVED_DEVICE event introduced with this
patch closes this gap as it is sent when the device is
already unbound from its device driver and almost completly
removed from the driver core.
With this event the IOMMU code can safely destroy any
mappings and other data structures when a device is removed.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jerry Hoemann <jerry.hoemann@hp.com>
Signed-off-by: Petri Gynther <pgynther@google.com>
Acked-by: Florian Fainelli <f.fainelli@gmai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
->page_mkwrite() is used by filesystems to allocate blocks under a page
which is becoming writeably mmapped in some process' address space. This
allows a filesystem to return a page fault if there is not enough space
available, user exceeds quota or similar problem happens, rather than
silently discarding data later when writepage is called.
However VFS fails to call ->page_mkwrite() in all the cases where
filesystems need it when blocksize < pagesize. For example when
blocksize = 1024, pagesize = 4096 the following is problematic:
ftruncate(fd, 0);
pwrite(fd, buf, 1024, 0);
map = mmap(NULL, 1024, PROT_WRITE, MAP_SHARED, fd, 0);
map[0] = 'a'; ----> page_mkwrite() for index 0 is called
ftruncate(fd, 10000); /* or even pwrite(fd, buf, 1, 10000) */
mremap(map, 1024, 10000, 0);
map[4095] = 'a'; ----> no page_mkwrite() called
At the moment ->page_mkwrite() is called, filesystem can allocate only
one block for the page because i_size == 1024. Otherwise it would create
blocks beyond i_size which is generally undesirable. But later at
->writepage() time, we also need to store data at offset 4095 but we
don't have block allocated for it.
This patch introduces a helper function filesystems can use to have
->page_mkwrite() called at all the necessary moments.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
skb_udp_segment is the function called from udp4_ufo_fragment to
segment a UDP tunnel packet. This function currently assumes
segmentation is transparent Ethernet bridging (i.e. VXLAN
encapsulation). This patch generalizes the function to
operate on either Ethertype or IP protocol.
The inner_protocol field must be set to the protocol of the inner
header. This can now be either an Ethertype or an IP protocol
(in a union). A new flag in the skbuff indicates which type is
effective. skb_set_inner_protocol and skb_set_inner_ipproto
helper functions were added to set the inner_protocol. These
functions are called from the point where the tunnel encapsulation
is occuring.
When skb_udp_tunnel_segment is called, the function to segment the
inner packet is selected based on the inner IP or Ethertype. In the
case of an IP protocol encapsulation, the function is derived from
inet[6]_offloads. In the case of Ethertype, skb->protocol is
set to the inner_protocol and skb_mac_gso_segment is called. (GRE
currently does this, but it might be possible to lookup the protocol
in offload_base and call the appropriate segmenation function
directly).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
