With larger devices there may be many widgets of the same type in series
in an audio path. Allow drivers to specify an additional level of ordering
within each widget type by adding a subsequence number to widgets and then
splitting operations on widgets so that widgets of the same type but
different sequence numbers are processed separately. A typical example
would be a supply widget which requires that another widget be enabled
to provide power or clocking.
SND_SOC_DAPM_PGA_S() and SND_SOC_DAPM_SUPPLY_S() macros are provided
allowing this to be used with PGAs and supplies as these are the most
commonly affected widgets.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
There's nothing worth hiding under the ifdef in the platform DMA
definitions, and we certainly don't want board code adding this in to
their platform data definitions, so we always expose the slave rx/tx
and device pointer members instead.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
All of the muxed IRQs presently populate the IRQ array verbosely, this
simply provides a trivial helper to do it for them.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Packet filter (BPF) doesnt need to disable softirqs, being fully
re-entrant and lock-less.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All users of the platform port data specify a mapbase where the driver
later derives the membase from. Now that UPF flags are taken in to
account for generic ioremapping we can kill off the port-specific membase
clobbering and simply use the generic paths.
This derives from a time when sh64 was not capable of using the generic
ioremap implementation and had employed early bolted DTLB mappings for
port access, which is no longer an issue.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Version 20110112.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Adding support for SNMP broadcast connection tracking. The SNMP
broadcast requests are now paired with the SNMP responses.
Thus allowing using SNMP broadcasts with firewall enabled.
Please refer to the following conversation:
http://marc.info/?l=netfilter-devel&m=125992205006600&w=2
Patrick McHardy wrote:
> > The best solution would be to add generic broadcast tracking, the
> > use of expectations for this is a bit of abuse.
> > The second best choice I guess would be to move the help() function
> > to a shared module and generalize it so it can be used for both.
This patch implements the "second best choice".
Since the netbios-ns conntrack module uses the same helper
functionality as the snmp, only one helper function is added
for both snmp and netbios-ns modules into the new object -
nf_conntrack_broadcast.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: hda - Fix initialization for HP 2011 notebooks
ALSA: hda - Add support for VMware controller
ALSA: hda - consitify string arrays
ALSA: hda - Add add multi-streaming playback for AD1988
ASoC: EP93xx: fixed LRCLK rate and DMA oper. in I2S code
ASoC: WM8990: msleep() takes milliseconds not jiffies
ALSA : au88x0 - Limit number of channels to fix Oops via OSS emu
ALSA: constify functions in ac97
ASoC: WL1273 FM radio: Fix breakage with MFD API changes
ALSA: hda - More coverage for odd-number channels elimination for HDMI
ALSA: hda - Store PCM parameters properly in HDMI open callback
ALSA: hda - Rearrange fixup struct in patch_realtek.c
ALSA: oxygen: Xonar DG: fix CS4245 register writes
ALSA: hda - Suppress the odd number of channels for HDMI
ALSA: hda - Add fixup-call in init callback
ALSA: hda - Reorganize fixup structure for Realtek
ALSA: hda - Apply Sony VAIO hweq fixup only once
ALSA: hda - Apply mario fixup only once
ALSA: hda - Remove unused fixup entry for ALC262
If an skb is to be NF_QUEUE'd, but no program has opened the queue, the
packet is dropped.
This adds a v2 target revision of xt_NFQUEUE that allows packets to
continue through the ruleset instead.
Because the actual queueing happens outside of the target context, the
'bypass' flag has to be communicated back to the netfilter core.
Unfortunately the only choice to do this without adding a new function
argument is to use the target function return value (i.e. the verdict).
In the NF_QUEUE case, the upper 16bit already contain the queue number
to use. The previous patch reduced NF_VERDICT_MASK to 0xff, i.e.
we now have extra room for a new flag.
If a hook issued a NF_QUEUE verdict, then the netfilter core will
continue packet processing if the queueing hook
returns -ESRCH (== "this queue does not exist") and the new
NF_VERDICT_FLAG_QUEUE_BYPASS flag is set in the verdict value.
Note: If the queue exists, but userspace does not consume packets fast
enough, the skb will still be dropped.
Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
NF_VERDICT_MASK is currently 0xffff. This is because the upper
16 bits are used to store errno (for NF_DROP) or the queue number
(NF_QUEUE verdict).
As there are up to 0xffff different queues available, there is no more
room to store additional flags.
At the moment there are only 6 different verdicts, i.e. we can reduce
NF_VERDICT_MASK to 0xff to allow storing additional flags in the 0xff00 space.
NF_VERDICT_BITS would then be reduced to 8, but because the value is
exported to userspace, this might cause breakage; e.g.:
e.g. 'queuenr = (1 << NF_VERDICT_BITS) | NF_QUEUE' would now break.
Thus, remove NF_VERDICT_BITS usage in the kernel and move the old value
to the 'userspace compat' section.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
My previous patch (netfilter: nf_nat: don't use atomic bit operation)
made a mistake when converting atomic_set to a normal bit 'or'.
IPS_*_BIT should be replaced with IPS_*.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Remove duplicate display resolution parameters from platform data as
one pair is quite enough.
Signed-off-by: Naveen Kumar Gaddipati <naveen.gaddipati@stericsson.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
RDMA: Update workqueue usage
RDMA/nes: Fix incorrect SFP+ link status detection on driver init
RDMA/nes: Fix SFP+ link down detection issue with switch port disable
RDMA/nes: Generate IB_EVENT_PORT_ERR/PORT_ACTIVE events
RDMA/nes: Fix bonding on iw_nes
IB/srp: Test only once whether iu allocation succeeded
IB/mlx4: Handle protocol field in multicast table
RDMA: Use vzalloc() to replace vmalloc()+memset(0)
mlx4_{core, ib, en}: Fix driver when sizeof (phys_addr_t) > sizeof (long)
IB/mthca: Fix driver when sizeof (phys_addr_t) > sizeof (long)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
ecryptfs: remove unnecessary decrypt when extending a file
ecryptfs: Fix ecryptfs_printk() size_t warnings
fs/ecryptfs: Add printf format/argument verification and fix fallout
ecryptfs: fixed testing of file descriptor flags
ecryptfs: test lower_file pointer when lower_file_mutex is locked
ecryptfs: missing initialization of the superblock 'magic' field
ecryptfs: moved ECRYPTFS_SUPER_MAGIC definition to linux/magic.h
ecryptfs: fix truncation error in ecryptfs_read_update_atime
* git://git.infradead.org/mtd-2.6: (59 commits)
mtd: mtdpart: disallow reading OOB past the end of the partition
mtd: pxa3xx_nand: NULL dereference in pxa3xx_nand_probe
UBI: use mtd->writebufsize to set minimal I/O unit size
mtd: initialize writebufsize in the MTD object of a partition
mtd: onenand: add mtd->writebufsize initialization
mtd: nand: add mtd->writebufsize initialization
mtd: cfi: add writebufsize initialization
mtd: add writebufsize field to mtd_info struct
mtd: OneNAND: OMAP2/3: prevent regulator sleeping while OneNAND is in use
mtd: OneNAND: add enable / disable methods to onenand_chip
mtd: m25p80: Fix JEDEC ID for AT26DF321
mtd: txx9ndfmc: limit transfer bytes to 512 (ECC provides 6 bytes max)
mtd: cfi_cmdset_0002: add support for Samsung K8D3x16UxC NOR chips
mtd: cfi_cmdset_0002: add support for Samsung K8D6x16UxM NOR chips
mtd: nand: ams-delta: drop omap_read/write, use ioremap
mtd: m25p80: add debugging trace in sst_write
mtd: nand: ams-delta: select for built-in by default
mtd: OneNAND: lighten scary initial bad block messages
mtd: OneNAND: OMAP2/3: add support for command line partitioning
mtd: nand: rearrange ONFI revision checking, add ONFI 2.3
...
Fix up trivial conflict in drivers/mtd/Kconfig as per DavidW.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
fs: fix address space warnings in ioctl_fiemap()
aio: check return value of create_workqueue()
hpfs_setattr error case avoids unlock_kernel
compat: copy missing fields in compat_statfs64 to user
compat: update comment of compat statfs syscalls
compat: remove unnecessary assignment in compat_rw_copy_check_uvector()
fs: FS_POSIX_ACL does not depend on BLOCK
fs: Remove unlikely() from fget_light()
fs: Remove unlikely() from fput_light()
fallocate should be a file operation
make the feature checks in ->fallocate future proof
staging: smbfs building fix
tidy up around finish_automount()
don't drop newmnt on error in do_add_mount()
Take the completion of automount into new helper
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (63 commits)
ARM: PL08x: cleanup comments
Update CONFIG_MD_RAID6_PQ to CONFIG_RAID6_PQ in drivers/dma/iop-adma.c
ARM: PL08x: fix a warning
Fix dmaengine_submit() return type
dmaengine: at_hdmac: fix race while monitoring channel status
dmaengine: at_hdmac: flags located in first descriptor
dmaengine: at_hdmac: use subsys_initcall instead of module_init
dmaengine: at_hdmac: no need set ACK in new descriptor
dmaengine: at_hdmac: trivial add precision to unmapping comment
dmaengine: at_hdmac: use dma_address to program DMA hardware
pch_dma: support new device ML7213 IOH
ARM: PL08x: prevent dma_set_runtime_config() reconfiguring memcpy channels
ARM: PL08x: allow dma_set_runtime_config() to return errors
ARM: PL08x: fix locking between prepare function and submit function
ARM: PL08x: introduce 'phychan_hold' to hold on to physical channels
ARM: PL08x: put txd's on the pending list in pl08x_tx_submit()
ARM: PL08x: rename 'desc_list' as 'pend_list'
ARM: PL08x: implement unmapping of memcpy buffers
ARM: PL08x: store prep_* flags in async_tx structure
ARM: PL08x: shrink srcbus/dstbus in txd structure
...
The definition of ECRYPTFS_SUPER_MAGIC has been moved to the include
file 'linux/magic.h' to become available to other kernel subsystems.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
In the embedded world there are often situations
where libraries are updated from a variety of sources,
for a variety of reasons, and with any number of
security characteristics. These differences
might include privilege required for a given library
provided interface to function properly, as occurs
from time to time in graphics libraries. There are
also cases where it is important to limit use of
libraries based on the provider of the library and
the security aware application may make choices
based on that criteria.
These issues are addressed by providing an additional
Smack label that may optionally be assigned to an object,
the SMACK64MMAP attribute. An mmap operation is allowed
if there is no such attribute.
If there is a SMACK64MMAP attribute the mmap is permitted
only if a subject with that label has all of the access
permitted a subject with the current task label.
Security aware applications may from time to time
wish to reduce their "privilege" to avoid accidental use
of privilege. One case where this arises is the
environment in which multiple sources provide libraries
to perform the same functions. An application may know
that it should eschew services made available from a
particular vendor, or of a particular version.
In support of this a secondary list of Smack rules has
been added that is local to the task. This list is
consulted only in the case where the global list has
approved access. It can only further restrict access.
Unlike the global last, if no entry is found on the
local list access is granted. An application can add
entries to its own list by writing to /smack/load-self.
The changes appear large as they involve refactoring
the list handling to accomodate there being more
than one rule list.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
The machine driver can't register the card directly and need to do this thru
soc-audio device creation
This patch allows the register and unregister card to be directly called by
machine drivers
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Harsha Priya <priya.harsha@intel.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
The fi_extents_start field of struct fiemap_extent_info is a
user pointer but was not marked as __user. This makes sparse
emit following warnings:
CHECK fs/ioctl.c
fs/ioctl.c:114:26: warning: incorrect type in argument 1 (different address spaces)
fs/ioctl.c:114:26: expected void [noderef] <asn:1>*dst
fs/ioctl.c:114:26: got struct fiemap_extent *[assigned] dest
fs/ioctl.c:202:14: warning: incorrect type in argument 1 (different address spaces)
fs/ioctl.c:202:14: expected void const volatile [noderef] <asn:1>*<noident>
fs/ioctl.c:202:14: got struct fiemap_extent *[assigned] fi_extents_start
fs/ioctl.c:212:27: warning: incorrect type in argument 1 (different address spaces)
fs/ioctl.c:212:27: expected void [noderef] <asn:1>*dst
fs/ioctl.c:212:27: got char *<noident>
Also add 'ufiemap' variable to eliminate unnecessary casts.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In fput_light(), there's an unlikely(fput_needed), which running on
my normal desktop doing firefox, xchat, evolution and part of my distcc farm,
and running the annotate branch profiler shows that the unlikely is not
very unlikely.
correct incorrect % Function File Line
------- --------- - -------- ---- ----
0 48 100 fput_light file.h 26
115828710 897415279 88 fput_light file.h 26
865271179 5286128445 85 fput_light file.h 26
19568539 8923664 31 fput_light file.h 26
12353677 3562279 22 fput_light file.h 26
267691 67062 20 fput_light file.h 26
15014853 348172 2 fput_light file.h 26
209258 205 0 fput_light file.h 26
1364164 0 0 fput_light file.h 26
Which gives 1032903812 times it was correct and 6203351846 times it was
incorrect, or 85% incorrect.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently all filesystems except XFS implement fallocate asynchronously,
while XFS forced a commit. Both of these are suboptimal - in case of O_SYNC
I/O we really want our allocation on disk, especially for the !KEEP_SIZE
case where we actually grow the file with user-visible zeroes. On the
other hand always commiting the transaction is a bad idea for fast-path
uses of fallocate like for example in recent Samba versions. Given
that block allocation is a data plane operation anyway change it from
an inode operation to a file operation so that we have the file structure
available that lets us check for O_SYNC.
This also includes moving the code around for a few of the filesystems,
and remove the already unnedded S_ISDIR checks given that we only wire
up fallocate for regular files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ib_wq is added, which is used as the common workqueue for infiniband
instead of the system workqueue. All system workqueue usages
including flush_scheduled_work() callers are converted to use and
flush ib_wq.
* cancel_delayed_work() + flush_scheduled_work() converted to
cancel_delayed_work_sync().
* qib_wq is removed and ib_wq is used instead.
This is to prepare for deprecation of flush_scheduled_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Cleanup the formatting of comments, remove some which don't make sense
anymore.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[fix conflict with 96a608a4]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
pmdp_get_and_clear/pmdp_clear_flush/pmdp_splitting_flush were trapped as
BUG() and they were defined only to diminish the risk of build issues on
not-x86 archs and to be consistent with the generic pte methods previously
defined in include/asm-generic/pgtable.h.
But they are causing more trouble than they were supposed to solve, so
it's simpler not to define them when THP is off.
This is also correcting the export of pmdp_splitting_flush which is
currently unused (x86 isn't using the generic implementation in
mm/pgtable-generic.c and no other arch needs that [yet]).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 415e12b237 ("PCI/ACPI: Request _OSC control once for each
root bridge (v3)") include/linux/pci-acpi.h is included by
drivers/pci/pcie/aer/aerdrv.c and if CONFIG_ACPI is unset, the bogus and
unnecessary alternative definition of acpi_find_root_bridge_handle()
causes a build error to occur.
Remove the offending piece of garbage.
Reported-and-tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (23 commits)
sanitize vfsmount refcounting changes
fix old umount_tree() breakage
autofs4: Merge the remaining dentry ops tables
Unexport do_add_mount() and add in follow_automount(), not ->d_automount()
Allow d_manage() to be used in RCU-walk mode
Remove a further kludge from __do_follow_link()
autofs4: Bump version
autofs4: Add v4 pseudo direct mount support
autofs4: Fix wait validation
autofs4: Clean up autofs4_free_ino()
autofs4: Clean up dentry operations
autofs4: Clean up inode operations
autofs4: Remove unused code
autofs4: Add d_manage() dentry operation
autofs4: Add d_automount() dentry operation
Remove the automount through follow_link() kludge code from pathwalk
CIFS: Use d_automount() rather than abusing follow_link()
NFS: Use d_automount() rather than abusing follow_link()
AFS: Use d_automount() rather than abusing follow_link()
Add an AT_NO_AUTOMOUNT flag to suppress terminal automount
...
Instead of splitting refcount between (per-cpu) mnt_count
and (SMP-only) mnt_longrefs, make all references contribute
to mnt_count again and keep track of how many are longterm
ones.
Accounting rules for longterm count:
* 1 for each fs_struct.root.mnt
* 1 for each fs_struct.pwd.mnt
* 1 for having non-NULL ->mnt_ns
* decrement to 0 happens only under vfsmount lock exclusive
That allows nice common case for mntput() - since we can't drop the
final reference until after mnt_longterm has reached 0 due to the rules
above, mntput() can grab vfsmount lock shared and check mnt_longterm.
If it turns out to be non-zero (which is the common case), we know
that this is not the final mntput() and can just blindly decrement
percpu mnt_count. Otherwise we grab vfsmount lock exclusive and
do usual decrement-and-check of percpu mnt_count.
For fs_struct.c we have mnt_make_longterm() and mnt_make_shortterm();
namespace.c uses the latter in places where we don't already hold
vfsmount lock exclusive and opencodes a few remaining spots where
we need to manipulate mnt_longterm.
Note that we mostly revert the code outside of fs/namespace.c back
to what we used to have; in particular, normal code doesn't need
to care about two kinds of references, etc. And we get to keep
the optimization Nick's variant had bought us...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The setsockopt() syscall to replace tables is already recorded
in the audit logs. This patch stores additional information
such as table name and netfilter protocol.
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch adds a new netfilter target which creates audit records
for packets traversing a certain chain.
It can be used to record packets which are rejected administraively
as follows:
-N AUDIT_DROP
-A AUDIT_DROP -j AUDIT --type DROP
-A AUDIT_DROP -j DROP
a rule which would typically drop or reject a packet would then
invoke the new chain to record packets before dropping them.
-j AUDIT_DROP
The module is protocol independant and works for iptables, ip6tables
and ebtables.
The following information is logged:
- netfilter hook
- packet length
- incomming/outgoing interface
- MAC src/dst/proto for ethernet packets
- src/dst/protocol address for IPv4/IPv6
- src/dst port for TCP/UDP/UDPLITE
- icmp type/code
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The physical address is never used by the device tree code when
allocating memory for unflattening. Change the architecture's alloc
hook to return the virutal address instead.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Unexport do_add_mount() and make ->d_automount() return the vfsmount to be
added rather than calling do_add_mount() itself. follow_automount() will then
do the addition.
This slightly complicates things as ->d_automount() normally wants to add the
new vfsmount to an expiration list and start an expiration timer. The problem
with that is that the vfsmount will be deleted if it has a refcount of 1 and
the timer will not repeat if the expiration list is empty.
To this end, we require the vfsmount to be returned from d_automount() with a
refcount of (at least) 2. One of these refs will be dropped unconditionally.
In addition, follow_automount() must get a 3rd ref around the call to
do_add_mount() lest it eat a ref and return an error, leaving the mount we
have open to being expired as we would otherwise have only 1 ref on it.
d_automount() should also add the the vfsmount to the expiration list (by
calling mnt_set_expiry()) and start the expiration timer before returning, if
this mechanism is to be used. The vfsmount will be unlinked from the
expiration list by follow_automount() if do_add_mount() fails.
This patch also fixes the call to do_add_mount() for AFS to propagate the mount
flags from the parent vfsmount.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Allow d_manage() to be called from pathwalk when it is in RCU-walk mode as well
as when it is in Ref-walk mode. This permits __follow_mount_rcu() to call
d_manage() directly. d_manage() needs a parameter to indicate that it is in
RCU-walk mode as it isn't allowed to sleep if in that mode (but should return
-ECHILD instead).
autofs4_d_manage() can then be set to retain RCU-walk mode if the daemon
accesses it and otherwise request dropping back to ref-walk mode.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Increase the autofs module sub-version so we can tell what kernel
implementation is being used from user space debug logging.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make NFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add an AT_NO_AUTOMOUNT flag to suppress terminal automounting of automount
point directories. This can be used by fstatat() users to permit the
gathering of attributes on an automount point and also prevent
mass-automounting of a directory of automount points by ls.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a dentry op (d_manage) to permit a filesystem to hold a process and make it
sleep when it tries to transit away from one of that filesystem's directories
during a pathwalk. The operation is keyed off a new dentry flag
(DCACHE_MANAGE_TRANSIT).
The filesystem is allowed to be selective about which processes it holds and
which it permits to continue on or prohibits from transiting from each flagged
directory. This will allow autofs to hold up client processes whilst letting
its userspace daemon through to maintain the directory or the stuff behind it
or mounted upon it.
The ->d_manage() dentry operation:
int (*d_manage)(struct path *path, bool mounting_here);
takes a pointer to the directory about to be transited away from and a flag
indicating whether the transit is undertaken by do_add_mount() or
do_move_mount() skipping through a pile of filesystems mounted on a mountpoint.
It should return 0 if successful and to let the process continue on its way;
-EISDIR to prohibit the caller from skipping to overmounted filesystems or
automounting, and to use this directory; or some other error code to return to
the user.
->d_manage() is called with namespace_sem writelocked if mounting_here is true
and no other locks held, so it may sleep. However, if mounting_here is true,
it may not initiate or wait for a mount or unmount upon the parameter
directory, even if the act is actually performed by userspace.
Within fs/namei.c, follow_managed() is extended to check with d_manage() first
on each managed directory, before transiting away from it or attempting to
automount upon it.
follow_down() is renamed follow_down_one() and should only be used where the
filesystem deliberately intends to avoid management steps (e.g. autofs).
A new follow_down() is added that incorporates the loop done by all other
callers of follow_down() (do_add/move_mount(), autofs and NFSD; whilst AFS, NFS
and CIFS do use it, their use is removed by converting them to use
d_automount()). The new follow_down() calls d_manage() as appropriate. It
also takes an extra parameter to indicate if it is being called from mount code
(with namespace_sem writelocked) which it passes to d_manage(). follow_down()
ignores automount points so that it can be used to mount on them.
__follow_mount_rcu() is made to abort rcu-walk mode if it hits a directory with
DCACHE_MANAGE_TRANSIT set on the basis that we're probably going to have to
sleep. It would be possible to enter d_manage() in rcu-walk mode too, and have
that determine whether to abort or not itself. That would allow the autofs
daemon to continue on in rcu-walk mode.
Note that DCACHE_MANAGE_TRANSIT on a directory should be cleared when it isn't
required as every tranist from that directory will cause d_manage() to be
invoked. It can always be set again when necessary.
==========================
WHAT THIS MEANS FOR AUTOFS
==========================
Autofs currently uses the lookup() inode op and the d_revalidate() dentry op to
trigger the automounting of indirect mounts, and both of these can be called
with i_mutex held.
autofs knows that the i_mutex will be held by the caller in lookup(), and so
can drop it before invoking the daemon - but this isn't so for d_revalidate(),
since the lock is only held on _some_ of the code paths that call it. This
means that autofs can't risk dropping i_mutex from its d_revalidate() function
before it calls the daemon.
The bug could manifest itself as, for example, a process that's trying to
validate an automount dentry that gets made to wait because that dentry is
expired and needs cleaning up:
mkdir S ffffffff8014e05a 0 32580 24956
Call Trace:
[<ffffffff885371fd>] :autofs4:autofs4_wait+0x674/0x897
[<ffffffff80127f7d>] avc_has_perm+0x46/0x58
[<ffffffff8009fdcf>] autoremove_wake_function+0x0/0x2e
[<ffffffff88537be6>] :autofs4:autofs4_expire_wait+0x41/0x6b
[<ffffffff88535cfc>] :autofs4:autofs4_revalidate+0x91/0x149
[<ffffffff80036d96>] __lookup_hash+0xa0/0x12f
[<ffffffff80057a2f>] lookup_create+0x46/0x80
[<ffffffff800e6e31>] sys_mkdirat+0x56/0xe4
versus the automount daemon which wants to remove that dentry, but can't
because the normal process is holding the i_mutex lock:
automount D ffffffff8014e05a 0 32581 1 32561
Call Trace:
[<ffffffff80063c3f>] __mutex_lock_slowpath+0x60/0x9b
[<ffffffff8000ccf1>] do_path_lookup+0x2ca/0x2f1
[<ffffffff80063c89>] .text.lock.mutex+0xf/0x14
[<ffffffff800e6d55>] do_rmdir+0x77/0xde
[<ffffffff8005d229>] tracesys+0x71/0xe0
[<ffffffff8005d28d>] tracesys+0xd5/0xe0
which means that the system is deadlocked.
This patch allows autofs to hold up normal processes whilst the daemon goes
ahead and does things to the dentry tree behind the automouter point without
risking a deadlock as almost no locks are held in d_manage() and none in
d_automount().
Signed-off-by: David Howells <dhowells@redhat.com>
Was-Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a dentry op (d_automount) to handle automounting directories rather than
abusing the follow_link() inode operation. The operation is keyed off a new
dentry flag (DCACHE_NEED_AUTOMOUNT).
This also makes it easier to add an AT_ flag to suppress terminal segment
automount during pathwalk and removes the need for the kludge code in the
pathwalk algorithm to handle directories with follow_link() semantics.
The ->d_automount() dentry operation:
struct vfsmount *(*d_automount)(struct path *mountpoint);
takes a pointer to the directory to be mounted upon, which is expected to
provide sufficient data to determine what should be mounted. If successful, it
should return the vfsmount struct it creates (which it should also have added
to the namespace using do_add_mount() or similar). If there's a collision with
another automount attempt, NULL should be returned. If the directory specified
by the parameter should be used directly rather than being mounted upon,
-EISDIR should be returned. In any other case, an error code should be
returned.
The ->d_automount() operation is called with no locks held and may sleep. At
this point the pathwalk algorithm will be in ref-walk mode.
Within fs/namei.c itself, a new pathwalk subroutine (follow_automount()) is
added to handle mountpoints. It will return -EREMOTE if the automount flag was
set, but no d_automount() op was supplied, -ELOOP if we've encountered too many
symlinks or mountpoints, -EISDIR if the walk point should be used without
mounting and 0 if successful. The path will be updated to point to the mounted
filesystem if a successful automount took place.
__follow_mount() is replaced by follow_managed() which is more generic
(especially with the patch that adds ->d_manage()). This handles transits from
directories during pathwalk, including automounting and skipping over
mountpoints (and holding processes with the next patch).
__follow_mount_rcu() will jump out of RCU-walk mode if it encounters an
automount point with nothing mounted on it.
follow_dotdot*() does not handle automounts as you don't want to trigger them
whilst following "..".
I've also extracted the mount/don't-mount logic from autofs4 and included it
here. It makes the mount go ahead anyway if someone calls open() or creat(),
tries to traverse the directory, tries to chdir/chroot/etc. into the directory,
or sticks a '/' on the end of the pathname. If they do a stat(), however,
they'll only trigger the automount if they didn't also say O_NOFOLLOW.
I've also added an inode flag (S_AUTOMOUNT) so that filesystems can mark their
inodes as automount points. This flag is automatically propagated to the
dentry as DCACHE_NEED_AUTOMOUNT by __d_instantiate(). This saves NFS and could
save AFS a private flag bit apiece, but is not strictly necessary. It would be
preferable to do the propagation in d_set_d_op(), but that doesn't normally
have access to the inode.
[AV: fixed breakage in case if __follow_mount_rcu() fails and nameidata_drop_rcu()
succeeds in RCU case of do_lookup(); we need to fall through to non-RCU case after
that, rather than just returning with ungrabbed *path]
Signed-off-by: David Howells <dhowells@redhat.com>
Was-Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
Update Pekka's email address in MAINTAINERS
mm/slab.c: make local symbols static
slub: Avoid use of slub_lock in show_slab_objects()
memory hotplug: one more lock on memory hotplug
