This callback will allow to simplify upcalls in further patches in this
series.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This is a cleanup patch.
Such helpers like nfs_cache_init() and nfs_cache_destroy() are redundant,
because they are just a wrappers around sunrpc_init_cache_detail() and
sunrpc_destroy_cache_detail() respectively.
So let's remove them completely and move corresponding logic to
nfs_cache_register_net() and nfs_cache_unregister_net() respectively (since
they are called together anyway).
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This cache was the first containerized and doesn't use net-aware cache
creation and destruction helpers.
This is a cleanup patch which just makes code looks clearer and reduce amount
of lines of code.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Now that we're allowing more DRC entries, it becomes a lot easier to hit
problems with XID collisions. In order to mitigate those, calculate a
checksum of up to the first 256 bytes of each request coming in and store
that in the cache entry, along with the total length of the request.
This initially used crc32, but Chuck Lever and Jim Rees pointed out that
crc32 is probably more heavyweight than we really need for generating
these checksums, and recommended looking at using the same routines that
are used to generate checksums for IP packets.
On an x86_64 KVM guest measurements with ftrace showed ~800ns to use
csum_partial vs ~1750ns for crc32. The difference probably isn't
terribly significant, but for now we may as well use csum_partial.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Stones-thrown-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When GSSAPI integrity signatures are in use, or when we're using GSSAPI
privacy with the v2 token format, there is a trailing checksum on the
xdr_buf that is returned.
It's checked during the authentication stage, and afterward nothing
cares about it. Ordinarily, it's not a problem since the XDR code
generally ignores it, but it will be when we try to compute a checksum
over the buffer to help prevent XID collisions in the duplicate reply
cache.
Fix the code to trim off the checksums after verifying them. Note that
in unwrap_integ_data, we must avoid trying to reverify the checksum if
the request was deferred since it will no longer be present when it's
revisited.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
These routines are used by server and client code, so having them in a
separate header would be best.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When copying an address, we should also copy the scopeid in the event
that this is a link-local address and the scope matters.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We don't really need to preallocate at all; just allocate and initialize
everything at once, but leave the sc_type field initially 0 to prevent
finding the stateid till it's fully initialized.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When free nfs-client, it must free the ->cl_stateids.
Cc: stable@kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Since we dynamically allocate them now, allow the system to call us up
to release them if it gets low on memory. Since these entries aren't
replaceable, only free ones that are expired or that are over the cap.
The the seeks value is set to '1' however to indicate that freeing the
these entries is low-cost.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It's not sufficient to only clean the cache when requests come in. What
if we have a flurry of activity and then the server goes idle? Add a
workqueue job that will clean the cache every RC_EXPIRE period.
Care is taken to only run this when we expect to have entries expiring.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There's no need to keep entries around that we're declaring RC_NOCACHE.
Ditto if there's a problem with the entry.
With this change too, there's no need to test for RC_UNUSED in the
search function. If the entry's in the hash table then it's either
INPROG or DONE.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
With the change to dynamically allocate entries, the cache is never
disabled on the fly. Remove this flag.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The existing code keeps a fixed-size cache of 1024 entries. This is much
too small for a busy server, and wastes memory on an idle one. This
patch changes the code to dynamically allocate and free these cache
entries.
A cap on the number of entries is retained, but it's much larger than
the existing value and now scales with the amount of low memory in the
machine.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
...otherwise, we end up with the list ordering wrong. Currently, it's
not a problem since we skip RC_INPROG entries, but keeping the ordering
strict will be necessary for a later patch that adds a cache cleaner.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Later, we'll need more than one call site for this, so break it out
into a new function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Add a preprocessor constant for the expiry time of cache entries, and
move the test for an expired entry into a function. Note that the current
code does not test for RC_INPROG. It just assumes that it won't take more
than 2 minutes to fill out an in-progress entry.
I'm not sure how valid that assumption is though, so let's just ensure
that we never consider an RC_INPROG entry to be expired.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Entries can only get a c_type of RC_REPLBUFF iff they are
RC_DONE. Therefore the test for RC_DONE isn't necessary here.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently we use kmalloc() which wastes a little bit of memory on each
allocation since it's a power of 2 allocator. Since we're allocating a
1024 of these now, and may need even more later, let's create a new
slabcache for them.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The locking rules for cache entries say that locking the cache_lock
isn't needed if you're just touching the current entry. Earlier
in this function we set rp->c_state to RC_UNUSED without any locking,
so I believe it's ok to do the same here.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently, it only stores the first 16 bytes of any address. struct
sockaddr_in6 is 28 bytes however, so we're currently ignoring the last
12 bytes of the address.
Expand the c_addr field to a sockaddr_in6, and cast it to a sockaddr_in
as necessary. Also fix the comparitor to use the existing RPC
helpers for this.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In func svc_export_parse, the uuid which used kmemdup to alloc will be
changed in func export_update.So the later kfree don't free this memory.
And it can't be free in func svc_export_parse because other place still
used.So put this operation in func svc_export_put.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The current code will allow silly things like:
echo "+2 +3 +4 +7.1">/proc/fs/nfsd/versions
Reported-by: Fan Chaoting <fanchaoting@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If CONFIG_LOCKDEP is disabled, then there would be a warning like this:
CC [M] fs/nfsd/nfs4state.o
fs/nfsd/nfs4state.c: In function ‘free_client’:
fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable]
So, let's add "maybe_unused" tag to this variable.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There is a race in enqueueing thread to a pool and
waking up a thread.
lockd doesn't wake up on reception of lock granted callback
if svc_wake_up() is called before lockd's thread is added
to a pool.
Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The write function doesn't be implemented in file content, and it's meaningless
to write data into this file directly. Remove write permission from it.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In the procedure of CREATE_SESSION, the state is locked after
alloc_conn_from_crses(). If the allocation fails, the function
goes to "out_free_session", and then "out" where there is an
unlock function.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In alloc_session(), numslots is the correct slot number used by the session.
But the slot number passed to nfsd4_put_drc_mem() is the one from nfs client.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It seems slightly simpler to make nfsd4_encode_fattr rather than its
callers responsible for advancing the write pointer on success.
(Also: the count == 0 check in the verify case looks superfluous.
Running out of buffer space is really the only reason fattr encoding
should fail with eresource.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull LED fix from Bryan Wu.
* 'fixes-for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
leds: leds-gpio: set devm_gpio_request_one() flags param correctly
commit a99d76f leds: leds-gpio: use gpio_request_one
changed the leds-gpio driver to use gpio_request_one() instead
of gpio_request() + gpio_direction_output()
Unfortunately, it also made a semantic change that breaks the
leds-gpio driver.
The gpio_request_one() flags parameter was set to:
GPIOF_DIR_OUT | (led_dat->active_low ^ state)
Since GPIOF_DIR_OUT is 0, the final flags value will just be the
XOR'ed value of led_dat->active_low and state.
This value were used to distinguish between HIGH/LOW output initial
level and call gpio_direction_output() accordingly.
With this new semantic gpio_request_one() will take the flags value
of 1 as a configuration of input direction (GPIOF_DIR_IN) and will
call gpio_direction_input() instead of gpio_direction_output().
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
{
..
if (flags & GPIOF_DIR_IN)
err = gpio_direction_input(gpio);
else
err = gpio_direction_output(gpio,
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
..
}
The right semantic is to evaluate led_dat->active_low ^ state and
set the output initial level explicitly.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reported-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Pull watchdog fixes from Wim Van Sebroeck:
"This fixes some small errors in the new da9055 driver, eliminates a
compiler warning and adds DT support for the twl4030_wdt driver (so
that we can have multiple watchdogs with DT on the omap platforms)."
* git://www.linux-watchdog.org/linux-watchdog:
watchdog: twl4030_wdt: add DT support
watchdog: omap_wdt: eliminate unused variable and a compiler warning
watchdog: da9055: Don't update wdt_dev->timeout in da9055_wdt_set_timeout error path
watchdog: da9055: Fix invalid free of devm_ allocated data
PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz
PCI: Remove spurious error for sriov_numvfs store and simplify flow
PCI: Add PCIe Link Capability link speed and width names
PCI/PM: Do not suspend port if any subordinate device needs PME polling
PCI: Work around Stratus ftServer broken PCIe hierarchy (fix DMI check)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)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=Ehs+
-----END PGP SIGNATURE-----
Merge tag '3.8-pci-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
"Some fixes for v3.8. They include a fix for the new SR-IOV sysfs
management support, an expanded quirk for Ricoh SD card readers, a
Stratus DMI quirk fix, and a PME polling fix."
* tag '3.8-pci-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz
PCI/PM: Do not suspend port if any subordinate device needs PME polling
PCI: Add PCIe Link Capability link speed and width names
PCI: Work around Stratus ftServer broken PCIe hierarchy (fix DMI check)
PCI: Remove spurious error for sriov_numvfs store and simplify flow
Commit 56c176c9ca ("UAPI: strip the _UAPI prefix from header guards
during header installation") strips the _UAPI prefix from header guards,
but only if there's a single space between the cpp directive and the
label.
Make it more flexible and able to handle tabs and multiple white space
characters.
Signed-off-by: David Howells <dhowell@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Empty files can get deleted by the patch program, so remove empty Kbuild
files and their links from the parent Kbuilds.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
overwriting a full page in the eCryptfs page cache, skip reading in and
decrypting the corresponding lower page.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=JNeQ
-----END PGP SIGNATURE-----
Merge tag 'ecryptfs-3.8-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Pull ecryptfs fixes from Tyler Hicks:
"Two self-explanatory fixes and a third patch which improves
performance: when overwriting a full page in the eCryptfs page cache,
skip reading in and decrypting the corresponding lower page."
* tag 'ecryptfs-3.8-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
fs/ecryptfs/crypto.c: make ecryptfs_encode_for_filename() static
eCryptfs: fix to use list_for_each_entry_safe() when delete items
eCryptfs: Avoid unnecessary disk read and data decryption during writing
Pull Ceph fixes from Sage Weil:
"Two of Alex's patches deal with a race when reseting server
connections for open RBD images, one demotes some non-fatal BUGs to
WARNs, and my patch fixes a protocol feature bit failure path."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
libceph: fix protocol feature mismatch failure path
libceph: WARN, don't BUG on unexpected connection states
libceph: always reset osds when kicking
libceph: move linger requests sooner in kick_requests()
Sasha was fuzzing with trinity and reported the following problem:
BUG: sleeping function called from invalid context at kernel/mutex.c:269
in_atomic(): 1, irqs_disabled(): 0, pid: 6361, name: trinity-main
2 locks held by trinity-main/6361:
#0: (&mm->mmap_sem){++++++}, at: [<ffffffff810aa314>] __do_page_fault+0x1e4/0x4f0
#1: (&(&mm->page_table_lock)->rlock){+.+...}, at: [<ffffffff8122f017>] handle_pte_fault+0x3f7/0x6a0
Pid: 6361, comm: trinity-main Tainted: G W
3.7.0-rc2-next-20121024-sasha-00001-gd95ef01-dirty #74
Call Trace:
__might_sleep+0x1c3/0x1e0
mutex_lock_nested+0x29/0x50
mpol_shared_policy_lookup+0x2e/0x90
shmem_get_policy+0x2e/0x30
get_vma_policy+0x5a/0xa0
mpol_misplaced+0x41/0x1d0
handle_pte_fault+0x465/0x6a0
This was triggered by a different version of automatic NUMA balancing
but in theory the current version is vunerable to the same problem.
do_numa_page
-> numa_migrate_prep
-> mpol_misplaced
-> get_vma_policy
-> shmem_get_policy
It's very unlikely this will happen as shared pages are not marked
pte_numa -- see the page_mapcount() check in change_pte_range() -- but
it is possible.
To address this, this patch restores sp->lock as originally implemented
by Kosaki Motohiro. In the path where get_vma_policy() is called, it
should not be calling sp_alloc() so it is not necessary to treat the PTL
specially.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
which could cause file system corruptions when performing file punch
operations.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=9R/D
-----END PGP SIGNATURE-----
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bug fixes from Ted Ts'o:
"Various bug fixes for ext4. Perhaps the most serious bug fixed is one
which could cause file system corruptions when performing file punch
operations."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: avoid hang when mounting non-journal filesystems with orphan list
ext4: lock i_mutex when truncating orphan inodes
ext4: do not try to write superblock on ro remount w/o journal
ext4: include journal blocks in df overhead calcs
ext4: remove unaligned AIO warning printk
ext4: fix an incorrect comment about i_mutex
ext4: fix deadlock in journal_unmap_buffer()
ext4: split off ext4_journalled_invalidatepage()
jbd2: fix assertion failure in jbd2_journal_flush()
ext4: check dioread_nolock on remount
ext4: fix extent tree corruption caused by hole punch
Remove the unused argument (formerly no_context) from mpol_parse_str()
and from mpol_to_str().
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recently I suggested using "mount -o remount,mpol=local /tmp" in NUMA
mempolicy testing. Very nasty. Reading /proc/mounts, /proc/pid/mounts
or /proc/pid/mountinfo may then corrupt one bit of kernel memory, often
in a page table (causing "Bad swap" or "Bad page map" warning or "Bad
pagetable" oops), sometimes in a vm_area_struct or rbnode or somewhere
worse. "mpol=prefer" and "mpol=prefer:Node" are equally toxic.
Recent NUMA enhancements are not to blame: this dates back to 2.6.35,
when commit e17f74af35 "mempolicy: don't call mpol_set_nodemask() when
no_context" skipped mpol_parse_str()'s call to mpol_set_nodemask(),
which used to initialize v.preferred_node, or set MPOL_F_LOCAL in flags.
With slab poisoning, you can then rely on mpol_to_str() to set the bit
for node 0x6b6b, probably in the next page above the caller's stack.
mpol_parse_str() is only called from shmem_parse_options(): no_context
is always true, so call it unused for now, and remove !no_context code.
Set v.nodes or v.preferred_node or MPOL_F_LOCAL as mpol_to_str() might
expect. Then mpol_to_str() can ignore its no_context argument also,
the mpol being appropriately initialized whether contextualized or not.
Rename its no_context unused too, and let subsequent patch remove them
(that's not needed for stable backporting, which would involve rejects).
I don't understand why MPOL_LOCAL is described as a pseudo-policy:
it's a reasonable policy which suffers from a confusing implementation
in terms of MPOL_PREFERRED with MPOL_F_LOCAL. I believe this would be
much more robust if MPOL_LOCAL were recognized in switch statements
throughout, MPOL_F_LOCAL deleted, and MPOL_PREFERRED use the (possibly
empty) nodes mask like everyone else, instead of its preferred_node
variant (I presume an optimization from the days before MPOL_LOCAL).
But that would take me too long to get right and fully tested.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
EPOLL_CTL_MOD sets the interest mask before calling f_op->poll() to
ensure events are not missed. Since the modifications to the interest
mask are not protected by the same lock as ep_poll_callback, we need to
ensure the change is visible to other CPUs calling ep_poll_callback.
We also need to ensure f_op->poll() has an up-to-date view of past
events which occured before we modified the interest mask. So this
barrier also pairs with the barrier in wq_has_sleeper().
This should guarantee either ep_poll_callback or f_op->poll() (or both)
will notice the readiness of a recently-ready/modified item.
This issue was encountered by Andreas Voellmy and Junchang(Jason) Wang in:
http://thread.gmane.org/gmane.linux.kernel/1408782/
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Voellmy <andreas.voellmy@yale.edu>
Tested-by: "Junchang(Jason) Wang" <junchang.wang@yale.edu>
Cc: netdev@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stanislav Kinsbursky