There are lots of sequences like this, especially in splice code:
if (pipe->inode)
mutex_lock(&pipe->inode->i_mutex);
/* do something */
if (pipe->inode)
mutex_unlock(&pipe->inode->i_mutex);
so introduce helpers which do the conditional locking and unlocking.
Also replace the inode_double_lock() call with a pipe_double_lock()
helper to avoid spreading the use of this functionality beyond the
pipe code.
This patch is just a cleanup, and should cause no behavioral changes.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Remove the now unused generic_file_splice_write_nolock() function.
It's conceptually broken anyway, because splice may need to wait for
pipe events so holding locks across the whole operation is wrong.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Split up __splice_from_pipe() into four helper functions:
splice_from_pipe_begin()
splice_from_pipe_next()
splice_from_pipe_feed()
splice_from_pipe_end()
splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe. splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).
This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().
This patch should not cause any change in behavior.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's a somewhat twisty maze of hints and behavioural modifiers, try
and clear it up a bit with some documentation.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's used by DM and MD and generally useful, so move the bio list
helpers into bio.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: warn about lockdep disabling after kernel taint, fix
Impact: build fix for Sparc and s390
Stephen Rothwell reported that the Sparc build broke:
In file included from kernel/panic.c:12:
include/linux/debug_locks.h: In function '__debug_locks_off':
include/linux/debug_locks.h:15: error: implicit declaration of function 'xchg'
due to:
9eeba61: lockdep: warn about lockdep disabling after kernel taint
There is some inconsistency between architectures about where exactly
xchg() is defined.
The traditional place is in system.h but the more logical point for it
is in atomic.h - where most architectures (especially new ones) have
it defined. These architecture also still offer it via system.h.
Some, such as Sparc or s390 only have it in asm/system.h and not available
via asm/atomic.h at all.
Use the widest set of headers in debug_locks.h and also include asm/system.h.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20090414144317.026498df.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Include <linux/types.h> in fiemap.h. Sam Ravnborg pointed out that this
was missing in this newly-exported header which uses the __u32 and __u64
types.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Data sheet at:
http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf
These sensors communicate over a 2 wire bus running a device specific
protocol. The complexity of the driver is mainly due to handling the
substantial delays between requesting a reading and the device pulling the
data line low to indicate that the data is available. This is handled by
an interrupt that is disabled under all other conditions.
I wasn't terribly clear on the best way to handle this, so comments on
that aspect would be particularly welcome!
Interpretation of the temperature depends on knowing the supply voltage.
If configured in a board config as a regulator consumer this is obtained
from the regulator subsystem. If not it should be provided in the
platform data.
I've placed this driver in the hwmon subsystem as it is definitely a
device that may be used for hardware monitoring and with it's relatively
slow response times (up to 120 millisecs to get a reading) a caching
strategy certainly seems to make sense!
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation about the meaning of the color component bitfield
lengths in pseudocolor modes is inconsistent. Fix it, so that it
indicates the correct interpretation everywhere, i.e. that 1 << length is
the number of palette entries.
Signed-off-by: Michal Januszewski <spock@gentoo.org>
Acked-by: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <syrjala@sci.fi>
Acked-by: Geert Uytterhoeven <geert.uytterhoeven@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing/filters: return proper error code when writing filter file
tracing/filters: allow user input integer to be oct or hex
tracing/filters: fix NULL pointer dereference
tracing/filters: NIL-terminate user input filter
ftrace: Output REC->var instead of __entry->var for trace format
Make __stringify support variable argument macros too
tracing: fix document references
tracing: fix splice return too large
tracing: update file->f_pos when splice(2) it
tracing: allocate page when needed
tracing: disable seeking for trace_pipe_raw
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: continue lock debugging despite some taints
lockdep: warn about lockdep disabling after kernel taint
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
i2c: Let new-style drivers implement attach_adapter
i2c: Fix sparse warnings for I2C_BOARD_INFO()
i2c-voodoo3: Deprecate in favor of tdfxfb
i2c-algo-pca: Fix use of uninitialized variable in debug message
When POSIX capabilities were introduced during the 2.1 Linux
cycle, the fs mask, which represents the capabilities which having
fsuid==0 is supposed to grant, did not include CAP_MKNOD and
CAP_LINUX_IMMUTABLE. However, before capabilities the privilege
to call these did in fact depend upon fsuid==0.
This patch introduces those capabilities into the fsmask,
restoring the old behavior.
See the thread starting at http://lkml.org/lkml/2009/3/11/157 for
reference.
Note that if this fix is deemed valid, then earlier kernel versions (2.4
and 2.2) ought to be fixed too.
Changelog:
[Mar 23] Actually delete old CAP_FS_SET definition...
[Mar 20] Updated against J. Bruce Fields's patch
Reported-by: Igor Zhbanov <izh1979@gmail.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: stable@kernel.org
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
percpu: unbreak alpha percpu
mutex: have non-spinning mutexes on s390 by default
Since the first argument to I2C_BOARD_INFO() must be a string constant,
there is no need to parenthesise it, and adding parentheses results in
an invalid initialiser for char[]. gcc obviously accepts this syntax as
an extension, but sparse complains, e.g.:
drivers/net/sfc/boards.c:173:2: warning: array initialized from parenthesized string constant
Therefore, remove the parentheses.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Impact: provide useful missing info for developers
Kernel taint can occur in several situations such as warnings,
load of prorietary or staging modules, bad page, etc...
But when such taint happens, a developer might still be working on
the kernel, expecting that lockdep is still enabled. But a taint
disables lockdep without ever warning about it.
Such a kernel behaviour doesn't really help for kernel development.
This patch adds this missing warning.
Since the taint is done most of the time after the main message that
explain the real source issue, it seems safe to warn about it inside
add_taint() so that it appears at last, without hurting the main
information.
v2: Use a generic helper to disable lockdep instead of an
open coded xchg().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1239412638-6739-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
For the time being, move the generic percpu_*() accessors to
linux/percpu.h.
asm-generic/percpu.h is meant to carry generic stuff for low level
stuff - declarations, definitions and pointer offset calculation
and so on but not for generic interface.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (27 commits)
xsysace: Fix dereferencing of cf_id after hd_driveid removal
at91_ide: turn on PIO 6 support
at91_ide: remove unused ide_mm_{outb,inb}
ide-cd: reverse NOT_READY sense key logic
ide: refactor tf_read() method
ide: refactor tf_load() method
ide: call write_devctl() method from tf_read() method
ide: move common code out of tf_load() method
ide: simplify 'struct ide_taskfile'
ide: replace IDE_TFLAG_* flags by IDE_VALID_*
ide-cd: fix intendation in cdrom_decode_status()
ide-cd: unify handling of fs and pc requests in cdrom_decode_status()
ide-cd: convert cdrom_decode_status() to use switch statements
ide-cd: update debugging support
ide-cd: respect REQ_QUIET for fs requests in cdrom_decode_status()
ide: remove unused #include <linux/version.h>
tx4939ide: Fix tx4939ide_{in,out}put_data_swap argument
tx493[89]ide: Remove big endian version of tx493[89]ide_tf_{load,read}
ide-cd: carve out an ide_cd_breathe()-helper for fs write requests
ide-cd: move status checking into the IRQ handler
...
