Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).
Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Add a new lock, dcache_lru_lock, to protect the dcache LRU list from concurrent
modification. d_lru is also protected by d_lock, which allows LRU lists to be
accessed without the lru lock, using RCU in future patches.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Add a new lock, dcache_hash_lock, to protect the dcache hash table from
concurrent modification. d_hash is also protected by d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Remove dcache_lock locking from hostfs filesystem, and move it into dcache
helpers. All that is required is a coherent path name. Protection from
concurrent modification of the namespace after path name generation is not
provided in current code, because dcache_lock is dropped before the path is
used.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
smpfs and ncpfs want to update a live dentry name in-place. Rather than
have them open code the locking, provide a documented dcache API.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Use vfat's method for dealing with negative dentries to preserve case,
rather than overwrite dentry name in d_revalidate, which is a bit ugly
and also gets in the way of doing lock-free path walking.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Use vfat's method for dealing with negative dentries to preserve case,
rather than overwrite dentry name in d_revalidate, which is a bit ugly
and also gets in the way of doing lock-free path walking.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.
This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Remove redundant (and incorrect, since dcache RCU lookup) dentry locking
documentation and point to the canonical document.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix configfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix cgroupfs so as not to do this.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The nr_unused counters count the number of objects on an LRU, and as such they
are synchronized with LRU object insertion and removal and scanning, and
protected under the LRU lock.
Making it per-cpu does not actually get any concurrency improvements because of
this lock, and summing the counter is much slower, and
incrementing/decrementing it costs more code size and is slower too.
These counters should stay per-LRU, which currently means global.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
d_validate has been broken for a long time.
kmem_ptr_validate does not guarantee that a pointer can be dereferenced
if it can go away at any time. Even rcu_read_lock doesn't help, because
the pointer might be queued in RCU callbacks but not executed yet.
So the parent cannot be checked, nor the name hashed. The dentry pointer
can not be touched until it can be verified under lock. Hashing simply
cannot be used.
Instead, verify the parent/child relationship by traversing parent's
d_child list. It's slow, but only ncpfs and the destaged smbfs care
about it, at this point.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (243 commits)
omap2: Make OMAP2PLUS select OMAP_DM_TIMER
OMAP4: hwmod data: Fix alignment and end of line in structurefields
OMAP4: hwmod data: Move the DMA structures
OMAP4: hwmod data: Move the smartreflex structures
OMAP4: hwmod data: Fix missing SIDLE_SMART_WKUP in smartreflexsysc
arm: omap: tusb6010: add name for MUSB IRQ
arm: omap: craneboard: Add USB EHCI support
omap2+: Initialize serial port for dynamic remuxing for n8x0
omap2+: Add struct omap_board_data and use it for platform level serial init
omap2+: Allow hwmod state changes to mux pads based on the state changes
omap2+: Add support for hwmod specific muxing of devices
omap2+: Add omap_mux_get_by_name
OMAP2: PM: fix compile error when !CONFIG_SUSPEND
MAINTAINERS: OMAP: hwmod: update hwmod code, data maintainership
OMAP4: Smartreflex framework extensions
OMAP4: hwmod: Add inital data for smartreflex modules.
OMAP4: PM: Program correct init voltages for scalable VDDs
OMAP4: Adding voltage driver support
OMAP4: Register voltage PMIC parameters with the voltage layer
OMAP3: PM: Program correct init voltages for VDD1 and VDD2
...
Fix up trivial conflict in arch/arm/plat-omap/Kconfig
A recent patch has added a die notifier to the shdma driver, however,
it registers a static die-notifier object in the probe routine, i.e.,
for each device instance. This is wrong and leads to a system lockup.
This patch moves the die notifier registration to module init and
exit routines respectively.
Reported-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Remove now unused IRQ demux code. All R-Mobile and
SH-Mobile processors should register IRQ demux
handlers during run-time.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Break-out GIC specific IRQ demux code from the file
entry-macro-intc.S and register during run-time.
Covers sh73a0.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Break-out INTC specific IRQ demux code from the file
entry-macro-intc.S and register during run-time.
Covers sh7367, sh7377 and sh7372.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Use the GIC demux code in asm/hardware/entry-macro-gic.S
on the R-Mobile / SH-Mobile processors.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
When CONFIG_ZBOOT_ROM is selected, the resulting zImage file will be small
boot loader and may be burned to rom or flash.
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6: (25 commits)
atyfb: Fix bootup hangs on sparc64.
sparc: update copyright in piggyback.c
sparc: unify strip command in boot/Makefile
sparc: rename piggyback_32 to piggyback
sparc: fix tftpboot.img for sparc64 on little-endian host
sparc: add $BITS to piggyback arguments
sparc: remove obsolete ELF support in piggyback_32.c
sparc: additional comments to piggyback_32.c
sparc: use _start for the start entry (like 64 bit does)
sparc: use trapbase in setup_arch
sparc: refactor piggy_32.c
Added support for ampopts in APBUART driver. Used in AMP systems.
APBUART: added raw AMBA vendor/device number to match against.
SPARC/LEON: avoid AMBAPP name duplicates in openprom fs when REG is missing
SPARC/LEON: added support for selecting Timer Core and Timer within core
LEON: added raw AMBA vendor/device number to find TIMER, IRQCTRL
SPARC/LEON: added support for IRQAMP IRQ Controller
SPARC/LEON: find IRQCTRL and Timer via OF-Tree, instead of hardcoded.
sparc: fix sparse warnings in arch/sparc/prom for 32 bit build
sparc: remove unused prom tree functions
...
Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for-linus' of git://codeaurora.org/quic/kernel/davidb/linux-msm: (35 commits)
mmc: msm_sdcc: Check for only DATA_END interrupt to end a request
mmc: msm_sdcc: Fix bug in PIO mode when data size is not word aligned
mmc: msm_sdcc: Reset SDCC in case of data transfer errors
mmc: msm_sdcc: Add prog done interrupt support
mmc: msm_sdcc: Fix possible circular locking dependency warning
MSM: Add USB support for MSM7x30
MSM: Add USB suport for QSD8x50
msm: initial framebuffer support
msm: add handling for clocks tagged as CLK_MINMAX
msm: trout: change name of pmdh_clk to mddi_clk
msm: add CLK_MINMAX to pmdh_clk
msm: trout: add gpio_to_irq
msm: iommu: Use the correct memory allocation flag
msm_serial: Remove redundant unlikely()
msm: iommu: Miscellaneous code cleanup
msm: iommu: Support cache-coherent memory access
msm: iommu: Definitions for extended memory attributes
msm: iommu: Kconfig dependency for the IOMMU API
msm: iommu: Check if device is already attached
msm: iommu: Kconfig item for cacheable page tables
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1436 commits)
cassini: Use local-mac-address prom property for Cassini MAC address
net: remove the duplicate #ifdef __KERNEL__
net: bridge: check the length of skb after nf_bridge_maybe_copy_header()
netconsole: clarify stopping message
netconsole: don't announce stopping if nothing happened
cnic: Fix the type field in SPQ messages
netfilter: fix export secctx error handling
netfilter: fix the race when initializing nf_ct_expect_hash_rnd
ipv4: IP defragmentation must be ECN aware
net: r6040: Return proper error for r6040_init_one
dcb: use after free in dcb_flushapp()
dcb: unlock on error in dcbnl_ieee_get()
net: ixp4xx_eth: Return proper error for eth_init_one
include/linux/if_ether.h: Add #define ETH_P_LINK_CTL for HPNA and wlan local tunnel
net: add POLLPRI to sock_def_readable()
af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.
net_sched: pfifo_head_drop problem
mac80211: remove stray extern
mac80211: implement off-channel TX using hw r-o-c offload
mac80211: implement hardware offload for remain-on-channel
...
Fallback on the local-mac-address prom property if the Cassini device
does not have an address programmed in the VPD ROM. This uses the same
technique as implemented by the sungem driver.
The problem was reported by Frans van Berckel using Debian kernel 2.6.34-7
on Sun Fire V440. udev was assigning a new eth<n> device name on each reboot
because the cassini driver was using a random MAC address.
Fix tested on 2.6.34-7 and 2.6.37 Sun Fire V440. Compile tested against
2.6.36 davem/sparc-2.6.git
Reported-by: Frans van Berckel <fberckel@xs4all.nl>
Tested-by: Frans van Berckel <fberckel@xs4all.nl>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Richard Mortimer <richm@oldelvet.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we are already in #ifdef __KERNEL__, we don't need to check it
again.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 25edd6946a ("sparc64: Get
rid of indirect p1275 PROM call buffer.") we can't pass virtual
addresses >4GB to PROM calls.
Largely this is never necessary in drivers because we have a copy of
the entire PROM device tree in the kernel and a set of of_*()
interfaces to access it.
Unfortunately there were some lingering prom calls in the atyfb
driver, in particular prom_finddevice() was being called with an
on-stack address which could be anywhere.
This code is actually probing for information we already have, the
PROM choosen console output device is stored in of_console_device so
all of this nasty code consolidates into a one-line comparison.
Next we have some prom_getintdefault() calls which are trivially
transformed into the equivalent of_getintprop_default().
Special thanks to Fabio, who figured out exactly where the bootup
was hanging. That made this bug trivial to fix.
Reported-by: Fabio M. Di NItto <fabbione@fabbione.net>
Reported-by: Sam Ravnborg <sam@ravnborg.org>
Reported-by: Frans van Berckel <fberckel@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Fabio M. Di NItto <fabbione@fabbione.net>
