Commit 3e6c6f630a ("Delay creation of
khcvd thread") moved the call of hvc_init from being a device_initcall
into hvc_alloc, and used a non-null hvc_driver as indication of whether
hvc_init had already been called.
The problem with this is that hvc_driver is only assigned a value
at the bottom of hvc_init, and so there is a window where multiple
hvc_alloc calls can be in progress at the same time and hence try
and call hvc_init multiple times. Previously the use of device_init
guaranteed that hvc_init was only called once.
This manifests itself as sporadic instances of two hvc_init calls
racing each other, and with the loser of the race getting -EBUSY
from tty_register_driver() and hence that virtual console fails:
Couldn't register hvc console driver
virtio-ports vport0p1: error -16 allocating hvc for port
Here we add an atomic_t to guarantee we'll never run hvc_init twice.
Cc: stable@vger.kernel.org # v2.6.24+
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 3e6c6f630a ("Delay creation of khcvd thread")
Reported-by: Jim Somerville <Jim.Somerville@windriver.com>
Tested-by: Jim Somerville <Jim.Somerville@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
instead of using sirf specific dma channel property like "sirf,uart-dma-rx-channel"
and "sirf,uart-dma-tx-channel", here we move to use generic dma dt-binding to get
the channel like:
- sirf,uart-dma-rx-channel = <21>;
- sirf,uart-dma-tx-channel = <2>;
+ dmas = <&dmac1 5>, <&dmac0 2>;
+ dma-names = "rx", "tx";
and we move dma_request_channel() to dma_request_slave_channel(), we don't need to
call sirfsoc dma filter function sirfsoc_dma_filter_id() again.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.
In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.
A typical case is observed with amba-pl011 and samsung-uart drivers.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.
In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.
A typical case is observed with amba-pl011 and samsung-uart drivers.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
config: x86_64-randconfig-x006 (attached as .config)
All warnings:
drivers/tty/serial/max310x.c: In function 'max310x_probe':
>> drivers/tty/serial/max310x.c:1240:1: warning: label 'out_uart' defined but not used [-Wunused-label]
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
config: make ARCH=alpha allyesconfig
All error/warnings:
drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
>> drivers/tty/serial/max310x.c:905:7: error: 'TIOCSRS485' undeclared (first use in this function)
drivers/tty/serial/max310x.c:905:7: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/tty/serial/max310x.c:906:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/max310x.c:929:7: error: 'TIOCGRS485' undeclared (first use in this function)
>> drivers/tty/serial/max310x.c:938:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
cc1: some warnings being treated as errors
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current code only wakes up the processes when the circle
buffer has less data then the WAKEUP_CHARS.
But sometimes, the circle buffer may has data more then the WAKEUP_CHARS,
in such case, the processes will hang.
This patch makes it always wakes up the processes in the TX callback.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes a driver bug which stopped the whole system (in case
of serial console).
This log message is not useful anyway as this information is
printed elsewhere.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Exar XR17V35x family of UARTs have an additional fractional divisor
register (DLD) which was not being used. Calculate and set this
register for these devices to reduce their baud rate error.
Signed-off-by: Joe Schultz <jschultz@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When echoes cannot be flushed to output (usually because the tty
has no more write room) and L_ECHO is subsequently turned off, then
when L_ECHO is turned back on, stale echoes are output.
Output completed echoes regardless of the L_ECHO setting:
1. before normal writes to that tty
2. if the tty was stopped by soft flow control and is being
restarted
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: <stable@vger.kernel.org> # 3.13.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8b9ade9f74 coming from Viresh Kumar "tty: serial: sirfsoc: drop
uart_port->lock before calling tty_flip_buffer_push()" broke sirfsoc uart
driver by knic:
[ 5.129122] BUG: spinlock already unlocked on CPU#0, ip6tables/1331
[ 5.132554] lock: sirfsoc_uart_ports+0x4/0x8a0, .magic: dead4ead,
.owner: <none>/-1, .owner_cpu: -1
[ 5.141651] CPU: 0 PID: 1331 Comm: ip6tables Tainted: G
W O 3.10.16 #3
[ 5.148866] [<c0013528>] (unwind_backtrace+0x0/0xe0) from
[<c0010e70>] (show_stack+0x10/0x14)
[ 5.157362] [<c0010e70>] (show_stack+0x10/0x14) from
[<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8)
[ 5.166125] [<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8) from
[<c03ff8b4>] (_raw_spin_unlock+0x8/0x40)
[ 5.175322] [<c03ff8b4>] (_raw_spin_unlock+0x8/0x40) from
[<c0203fcc>] (sirfsoc_uart_pio_rx_chars+0xa4/0xc0)
[ 5.185120] [<c0203fcc>]
(sirfsoc_uart_pio_rx_chars+0xa4/0xc0) from [<c0204fb8>]
(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0)
[ 5.195875] [<c0204fb8>]
(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0) from [<c0024b50>]
(tasklet_action+0x8c/0xec)
[ 5.205673] [<c0024b50>] (tasklet_action+0x8c/0xec) from
[<c00242a8>] (__do_softirq+0xec/0x1d4)
[ 5.214347] [<c00242a8>] (__do_softirq+0xec/0x1d4) from
[<c0024428>] (do_softirq+0x48/0x54)
[ 5.222674] [<c0024428>] (do_softirq+0x48/0x54) from
[<c0024690>] (irq_exit+0x74/0xc0)
[ 5.230573] [<c0024690>] (irq_exit+0x74/0xc0) from
[<c000e1e8>] (handle_IRQ+0x6c/0x90)
[ 5.238465] [<c000e1e8>] (handle_IRQ+0x6c/0x90) from
[<c000d500>] (__irq_svc+0x40/0x70)
[ 5.246446] [<c000d500>] (__irq_svc+0x40/0x70) from
[<c0092e7c>] (mark_page_accessed+0xc/0x68)
[ 5.255034] [<c0092e7c>] (mark_page_accessed+0xc/0x68) from
[<c00a2a4c>] (unmap_single_vma+0x3bc/0x550)
[ 5.264402] [<c00a2a4c>] (unmap_single_vma+0x3bc/0x550) from
[<c00a3b4c>] (unmap_vmas+0x44/0x54)
[ 5.273164] [<c00a3b4c>] (unmap_vmas+0x44/0x54) from
[<c00a81a8>] (exit_mmap+0xc4/0x1e0)
[ 5.281233] [<c00a81a8>] (exit_mmap+0xc4/0x1e0) from
[<c001bb78>] (mmput+0x3c/0xdc)
[ 5.288868] [<c001bb78>] (mmput+0x3c/0xdc) from [<c0021b0c>]
(do_exit+0x30c/0x828)
[ 5.296413] [<c0021b0c>] (do_exit+0x30c/0x828) from
[<c0022dac>] (do_group_exit+0x4c/0xb0)
[ 5.304653] [<c0022dac>] (do_group_exit+0x4c/0xb0) from
[<c0022e20>] (__wake_up_parent+0x0/0x18)
Root cause:
the commit dropped uart_port->lock before calling tty_flip_buffer_push(), but in sirfsoc-uart,
sirfsoc_uart_pio_rx_chars() can be called by sirfsoc_rx_tmo_process_tl(). here uart_port->lock
has not been taken yet. so that caused unpaired lock/unlock.
Solution:
This patch is doing a quick fix for that, it adds spin_lock/unlock(&port->lock) protect to
sirfsoc_uart_pio_rx_chars() in sirfsoc_rx_tmo_process_tl() to keep spin_lock/unlock in pair.
Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Aparently 9865 uses standard BAR encoding scheme (unlike 99xx cards).
Current pci_netmos_9900_setup() uses wrong BAR indices for the 9865 PCI
device, function 2. Using standard BAR indices makes all 6 ports work
for me. Thus disable the NetMos 9900 quirk for NetMos 9865 pci device.
For the reference, here is the relevant part of lspci for my device:
02:07.0 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
Subsystem: Device a000:1000
Flags: bus master, medium devsel, latency 32, IRQ 17
I/O ports at ac00 [size=8]
Memory at fcfff000 (32-bit, non-prefetchable) [size=4K]
Memory at fcffe000 (32-bit, non-prefetchable) [size=4K]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
02:07.1 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
Subsystem: Device a000:1000
Flags: bus master, medium devsel, latency 32, IRQ 18
I/O ports at a800 [size=8]
Memory at fcffd000 (32-bit, non-prefetchable) [size=4K]
Memory at fcffc000 (32-bit, non-prefetchable) [size=4K]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
02:07.2 Communication controller: MosChip Semiconductor Technology Ltd.
PCI 9865 Multi-I/O Controller
Subsystem: Device a000:3004
Flags: bus master, medium devsel, latency 32, IRQ 19
I/O ports at a400 [size=8]
I/O ports at a000 [size=8]
I/O ports at 9c00 [size=8]
I/O ports at 9800 [size=8]
Memory at fcffb000 (32-bit, non-prefetchable) [size=4K]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit eafbe67f84,
n_tty: Refactor input_available_p() by call site
broke poll() when TIME_CHAR(tty) and MIN_CHAR(tty) are both 0.
When TIME_CHAR and MIN_CHAR are both 0, input is available if the
read_cnt is 1 (not 0).
Reported-by: Eric Dumazet <edumazet@google.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the gpio is not yet available we better also
defer the probing in the rs485 case.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_PM will be set if either or both CONFIG_PM_SLEEP and
CONFIG_PM_RUNTIME is set. Compiling the driver with !CONFIG_PM_SLEEP causes
following compilation warnings:
drivers/tty/serial/8250/8250_dw.c:404:12: warning: ‘dw8250_suspend’ defined but not used [-Wunused-function]
drivers/tty/serial/8250/8250_dw.c:413:12: warning: ‘dw8250_resume’ defined but not used [-Wunused-function]
Fix this by using CONFIG_PM_SLEEP instead.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the info message about a missing wakeirq for uart is printed
every time the serial driver's startup function is called. This happens
multiple times and not just once.
This can cause lots of extra messages at boot time, slowing things down. It is
caused by commit 2a0b965cfb (serial: omap: Add support for optional wake-up)
which was applied for v3.13-rc1.
This patch moves the infomessage to the probe function to display it
only once.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds the devicetree documentation for the Maxim MAX310X UARTs.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds devicetree support for the MAX310X serial driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes some unused definitions from driver code and
sort #includes alphabetically.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support for RS-485 (TIOCSRS485/TIOCGRS485) IOCTLs.
As a result this patch eliminate private driver header.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Always register GPIOs and use dynamic GPIO ID assignment.
This is no much worth if GPIOs is not used, but helps remove
private driver header and add DT support in the future.
Additionally, patch adds missing uart_unregister_driver()
call if probe() fails.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes "frequency" parameter from MAX310X platform_data
and uses CLK API for getting clock. Clock type (XTAL/OSC) is
determined by clk name.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch move all SPI-dependent stuff in one place. This include move
PM-function definitions out of CONFIG_SPI_MASTER and move regmap
initialization out of common probe into CONFIG_SPI_MASTER which
may help to add I2C support in the future for this driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since 93abe8e4 (clk: add non CONFIG_HAVE_CLK routines) code using clk.h
like this driver needs not depend on HAVE_CLK.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes excess IRQ checks at driver probe().
IRQ validation is already provided by request_threaded_irq().
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch replaces loopback mode support from platform data to
dynamic setup with TIOCMSET ioctl.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Serial core calls set_termios() after port startup, so there are
no reason to setup port twice.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These callbacks were previously used for the IC power initialization.
If this initialization will be needed in the future, it should be
implemented with the regulator API.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch provide more precisely setup of baud rate generator.
If the result of division has a remainder, we use the multiplier
for the base frequency. Additionally, we report result baud rate
back to serial core.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hardware supported by the driver is only found on SUPERH or
ARCH_SHMOBILE platforms. Restrict non-COMPILE_TEST compilation to them.
Cc: linux-serial@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the -generic suffix from the compatible string in the serial port
DT bindings example.
Cc: devicetree@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add CONFIG_DEBUG_FS to 'char name' in order to fix the following
build warning, because 'char name' is used only when CONFIG_DEBUG_FS
is enabled.
drivers/tty/serial/pch_uart.c:1765:7: warning: unused variable 'name' [-Wunused-variable]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following compile warning about cast to pointer from
integer of different size.
drivers/tty/serial/sh-sci.c:2021:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the info message about a missing wakeirq for uart is printed
every time the serial driver's startup function is called. This happens
multiple times and not just once.
This patch moves the infomessage to the probe function to display it
only once.
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implement the polling functionality for the MSM serial driver.
This allows us to use KGDB on this hardware.
Cc: David Brown <davidb@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull SELinux fixes from James Morris.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
SELinux: Fix kernel BUG on empty security contexts.
selinux: add SOCK_DIAG_BY_FAMILY to the list of netlink message types
Pull vfs fixes from Al Viro:
"A couple of fixes, both -stable fodder. The O_SYNC bug is fairly
old..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix a kmap leak in virtio_console
fix O_SYNC|O_APPEND syncing the wrong range on write()
While we are at it, don't do kmap() under kmap_atomic(), *especially*
for a page we'd allocated with GFP_KERNEL. It's spelled "page_address",
and had that been more than that, we'd have a real trouble - kmap_high()
can block, and doing that while holding kmap_atomic() is a Bad Idea(tm).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
pos_before_write .. pos_before_write + written - 1
instead. Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().
All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().
The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull btrfs fixes from Chris Mason:
"This is a small collection of fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix data corruption when reading/updating compressed extents
Btrfs: don't loop forever if we can't run because of the tree mod log
btrfs: reserve no transaction units in btrfs_ioctl_set_features
btrfs: commit transaction after setting label and features
Btrfs: fix assert screwup for the pending move stuff
Pull perf fixes from Ingo Molnar:
"Tooling fixes, mostly related to the KASLR fallout, but also other
fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf buildid-cache: Check relocation when checking for existing kcore
perf tools: Adjust kallsyms for relocated kernel
perf tests: No need to set up ref_reloc_sym
perf symbols: Prevent the use of kcore if the kernel has moved
perf record: Get ref_reloc_sym from kernel map
perf machine: Set up ref_reloc_sym in machine__create_kernel_maps()
perf machine: Add machine__get_kallsyms_filename()
perf tools: Add kallsyms__get_function_start()
perf symbols: Fix symbol annotation for relocated kernel
perf tools: Fix include for non x86 architectures
perf tools: Fix AAAAARGH64 memory barriers
perf tools: Demangle kernel and kernel module symbols too
perf/doc: Remove mention of non-existent set_perf_event_pending() from design.txt
When using a mix of compressed file extents and prealloc extents, it
is possible to fill a page of a file with random, garbage data from
some unrelated previous use of the page, instead of a sequence of zeroes.
A simple sequence of steps to get into such case, taken from the test
case I made for xfstests, is:
_scratch_mkfs
_scratch_mount "-o compress-force=lzo"
$XFS_IO_PROG -f -c "pwrite -S 0x06 -b 18670 266978 18670" $SCRATCH_MNT/foobar
$XFS_IO_PROG -c "falloc 26450 665194" $SCRATCH_MNT/foobar
$XFS_IO_PROG -c "truncate 542872" $SCRATCH_MNT/foobar
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar
This results in the following file items in the fs tree:
item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160
inode generation 6 transid 6 size 542872 block group 0 mode 100600
item 5 key (257 INODE_REF 256) itemoff 15863 itemsize 16
inode ref index 2 namelen 6 name: foobar
item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
extent data disk byte 0 nr 0 gen 6
extent data offset 0 nr 24576 ram 266240
extent compression 0
item 7 key (257 EXTENT_DATA 24576) itemoff 15757 itemsize 53
prealloc data disk byte 12849152 nr 241664 gen 6
prealloc data offset 0 nr 241664
item 8 key (257 EXTENT_DATA 266240) itemoff 15704 itemsize 53
extent data disk byte 12845056 nr 4096 gen 6
extent data offset 0 nr 20480 ram 20480
extent compression 2
item 9 key (257 EXTENT_DATA 286720) itemoff 15651 itemsize 53
prealloc data disk byte 13090816 nr 405504 gen 6
prealloc data offset 0 nr 258048
The on disk extent at offset 266240 (which corresponds to 1 single disk block),
contains 5 compressed chunks of file data. Each of the first 4 compress 4096
bytes of file data, while the last one only compresses 3024 bytes of file data.
Therefore a read into the file region [285648 ; 286720[ (length = 4096 - 3024 =
1072 bytes) should always return zeroes (our next extent is a prealloc one).
The solution here is the compression code path to zero the remaining (untouched)
bytes of the last page it uncompressed data into, as the information about how
much space the file data consumes in the last page is not known in the upper layer
fs/btrfs/extent_io.c:__do_readpage(). In __do_readpage we were correctly zeroing
the remainder of the page but only if it corresponds to the last page of the inode
and if the inode's size is not a multiple of the page size.
This would cause not only returning random data on reads, but also permanently
storing random data when updating parts of the region that should be zeroed.
For the example above, it means updating a single byte in the region [285648 ; 286720[
would store that byte correctly but also store random data on disk.
A test case for xfstests follows soon.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>
A user reported a 100% cpu hang with my new delayed ref code. Turns out I
forgot to increase the count check when we can't run a delayed ref because of
the tree mod log. If we can't run any delayed refs during this there is no
point in continuing to look, and we need to break out. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Added in patch "btrfs: add ioctls to query/change feature bits online"
modifications to superblock don't need to reserve metadata blocks when
starting a transaction.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
