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2010-05-14mtd: nand: support alternate BB marker locations on MLCKevin Cernekee
This is a slightly modified version of a patch submitted last year by Reuben Dowle <reuben.dowle@navico.com>. His original comments follow: This patch adds support for some MLC NAND flashes that place the BB marker in the LAST page of the bad block rather than the FIRST page used for SLC NAND and other types of MLC nand. Lifted from Samsung datasheet for K9LG8G08U0A (1Gbyte MLC NAND): " Identifying Initial Invalid Block(s) All device locations are erased(FFh) except locations where the initial invalid block(s) information is written prior to shipping. The initial invalid block(s) status is defined by the 1st byte in the spare area. Samsung makes sure that the last page of every initial invalid block has non-FFh data at the column address of 2,048. ... " As far as I can tell, this is the same for all Samsung MLC nand, and in fact the samsung bsp for the processor used in our project (s3c6410) actually contained a hack similar to this patch but less portable to enable use of their NAND parts. I discovered this problem when trying to use a Micron NAND which does not used this layout - I wish samsung would put their stuff in main-line to avoid this type of problem. Currently this patch causes all MLC nand with manufacturer codes from Samsung and ST(Numonyx) to use this alternative location, since these are the manufactures that I know of that use this layout. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: nand: extend NAND flash detection to new MLC chipsKevin Cernekee
Some of the newer MLC devices have a 6-byte ID sequence in which several field definitions differ from older chips in a manner that is not backward compatible. For instance: Samsung K9GAG08U0M (5-byte sequence): ec d5 14 b6 74 4th byte, bits 1:0 encode the page size: 0=1KiB, 1=2KiB, 2=4KiB, 3=8KiB 4th byte, bits 5:4 encode the block size: 0=64KiB, 1=128KiB, ... 4th byte, bit 6 encodes the OOB size: 0=8B/512B, 1=16B/512B Samsung K9GAG08U0D (6-byte sequence): ec d5 94 29 34 41 4th byte, bits 1:0 encode the page size: 0=2KiB, 1=4KiB, 3=8KiB, 4=rsvd 4th byte, bits 7;5:4 encode the block size: 0=128KiB, 1=256KiB, ... 4th byte, bits 6;3:2 encode the OOB size: 1=128B/page, 2=218B/page This patch uses the new 6-byte scheme if the following conditions are all true: 1) The ID code wraps around after exactly 6 bytes 2) Manufacturer is Samsung 3) 6th byte is zero The patch also extends the maximum OOB size from 128B to 256B. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: suppress warnings in inline_map_read()Kevin Cernekee
With gcc 4.4.3 -O2 on MIPS32: drivers/mtd/chips/cfi_util.c: In function 'cfi_qry_present': include/linux/mtd/map.h:390: warning: 'r' may be used uninitialized in this function include/linux/mtd/map.h:375: note: 'r' was declared here include/linux/mtd/map.h:390: warning: 'r' may be used uninitialized in this function include/linux/mtd/map.h:375: note: 'r' was declared here Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: map.h: add missing bug.h includeKevin Cernekee
Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: onenand: add new callback for bufferram readKyungmin Park
This patch adds a new callback for the underlying drivers, which is called instead of accessing the buffer ram directly. This callback will be used by Samsung OneNAND driver to implement DMA transfers on S5PC110 SoC. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: onenand: allocate verify buffer in the coreKyungmin Park
This patch extends OneNAND core code with support for OneNAND verify write check. This is done by allocating the buffer for verify read directly from the core code. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: onenand: add support for chips with 4KiB page sizeKyungmin Park
This patch adds support for OneNAND chips that have 4KiB page size. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: chips: use common manufacturer codes in jedec_probe()Wolfram Sang
Factor out old manufacturers and use the generic ones from cfi.h Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-14mtd: cfi_probe: add support for SST 0x0701 vendornameGuillaume LECERF
SST 39VF160x and 39VF320x chips use vendorname id 0x0701 and alternative unlock addresses. Add support for them in cfi_probe.c. Signed-off-by: Guillaume LECERF <glecerf@gmail.com> Reviewed-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-12mtd/nand/sh_flctl: Move function mtd_to_flctl to fix build failurePeter Huewe
This patch fixes a build failure[1] by simply moving the function mtd_to_flctl beneath the definition of sh_flctl which it uses. BF introduced by patch 'mtd/nand/sh_flctl: Replace the dangerous mtd_to_flctl macro' (67026418) Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-10Merge branch 'master' of ↵David Woodhouse
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/mtd/mtdcore.c Pull in the bdi fixes and ARM platform changes that other outstanding patches depend on.
2010-05-10mtd: fix a huge latency problem in the MTD CFI and LPDDR flash drivers.Stefani Seibold
The use of a memcpy() during a spinlock operation will cause very long thread context switch delays if the flash chip bandwidth is low and the data to be copied large, because a spinlock will disable preemption. For example: A flash with 6,5 MB/s bandwidth will cause under ubifs, which request sometimes 128 KiB (the flash erase size), a preemption delay of 20 milliseconds. High priority threads will not be served during this time, regardless whether this threads access the flash or not. This behavior breaks real time. The patch changes all the use of spin_lock operations for xxxx->mutex into mutex operations, which is exact what the name says and means. I have checked the code of the drivers and there is no use of atomic pathes like interrupt or timers. The mtdoops facility will also not be used by this drivers. So it is dave to replace the spin_lock against mutex. There is no performance regression since the mutex is normally not acquired. Changelog: 06.03.2010 First release 26.03.2010 Fix mutex[1] issue and tested it for compile failure Signed-off-by: Stefani Seibold <stefani@seibold.net> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-10mtd/nand/sh_flctl: Replace the dangerous mtd_to_flctl macroFerenc Wagner
The original macro worked only when applied to variables named 'mtd'. While this could have been fixed by simply renaming the macro argument, a more type-safe replacement is preferred. Signed-off-by: Ferenc Wagner <wferi@niif.hu> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-10mtd: mtdram.h: checkpatch cleanupAndrea Gelmini
include/linux/mtd/mtdram.h:6: ERROR: code indent should use tabs where possible Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-07Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: create rcu_my_thread_group_empty() wrapper memcg: css_id() must be called under rcu_read_lock() cgroup: Check task_lock in task_subsys_state() sched: Fix an RCU warning in print_task() cgroup: Fix an RCU warning in alloc_css_id() cgroup: Fix an RCU warning in cgroup_path() KEYS: Fix an RCU warning in the reading of user keys KEYS: Fix an RCU warning
2010-05-06rcu: create rcu_my_thread_group_empty() wrapperPaul E. McKenney
Some RCU-lockdep splat repairs need to know whether they are running in a single-threaded process. Unfortunately, the thread_group_empty() primitive is defined in sched.h, and can induce #include hell. This commit therefore introduces a rcu_my_thread_group_empty() wrapper that is defined in rcupdate.c, thus avoiding the need to include sched.h everywhere. Signed-off-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
2010-05-04cgroup: Check task_lock in task_subsys_state()Li Zefan
Expand task_subsys_state()'s rcu_dereference_check() to include the full locking rule as documented in Documentation/cgroups/cgroups.txt by adding a check for task->alloc_lock being held. This fixes an RCU false positive when resuming from suspend. The warning comes from freezer cgroup in cgroup_freezing_or_frozen(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-05-04i2c-core: Use per-adapter userspace device listsJean Delvare
Using a single list for all userspace devices leads to a dead lock on multiplexed buses in some circumstances (mux chip instantiated from userspace). This is solved by using a separate list for each bus segment. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Michael Lawnick <ml.lawnick@gmx.de>
2010-04-30USB: rename usb_buffer_alloc() and usb_buffer_free()Daniel Mack
For more clearance what the functions actually do, usb_buffer_alloc() is renamed to usb_alloc_coherent() usb_buffer_free() is renamed to usb_free_coherent() They should only be used in code which really needs DMA coherency. [added compatibility macros so we can convert things easier - gregkh] Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Pedro Ribeiro <pedrib@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-04-29Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6Linus Torvalds
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: nfs: fix memory leak in nfs_get_sb with CONFIG_NFS_V4 nfs: fix some issues in nfs41_proc_reclaim_complete() NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clear NFS: Fix an unstable write data integrity race nfs: testing for null instead of ERR_PTR() NFS: rsize and wsize settings ignored on v4 mounts NFSv4: Don't attempt an atomic open if the file is a mountpoint SUNRPC: Fix a bug in rpcauth_prune_expired
2010-04-28Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: coda: move backing-dev.h kernel include inside __KERNEL__ mtd: ensure that bdi entries are properly initialized and registered Move mtd_bdi_*mappable to mtdcore.c btrfs: convert to using bdi_setup_and_register() Catch filesystems lacking s_bdi drbd: Terminate a connection early if sending the protocol fails drbd: fix memory leak Fix JFFS2 sync silent failure smbfs: add bdi backing to mount session ncpfs: add bdi backing to mount session exofs: add bdi backing to mount session ecryptfs: add bdi backing to mount session coda: add bdi backing to mount session cifs: add bdi backing to mount session afs: add bdi backing to mount session. 9p: add bdi backing to mount session bdi: add helper function for doing init and register of a bdi for a file system block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timer
2010-04-28coda: move backing-dev.h kernel include inside __KERNEL__Jens Axboe
Otherwise we must export backing-dev.h as well, which doesn't make any sense. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-25Catch filesystems lacking s_bdiJörn Engel
noop_backing_dev_info is used only as a flag to mark filesystems that don't have any backing store, like tmpfs, procfs, spufs, etc. Signed-off-by: Joern Engel <joern@logfs.org> Changed the BUG_ON() to a WARN_ON(). Note that adding dirty inodes to the noop_backing_dev_info is not legal and will not result in them being flushed, but we already catch this condition in __mark_inode_dirty() when checking for a registered bdi. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-24hugetlb: fix infinite loop in get_futex_key() when backed by huge pagesMel Gorman
If a futex key happens to be located within a huge page mapped MAP_PRIVATE, get_futex_key() can go into an infinite loop waiting for a page->mapping that will never exist. See https://bugzilla.redhat.com/show_bug.cgi?id=552257 for more details about the problem. This patch makes page->mapping a poisoned value that includes PAGE_MAPPING_ANON mapped MAP_PRIVATE. This is enough for futex to continue but because of PAGE_MAPPING_ANON, the poisoned value is not dereferenced or used by futex. No other part of the VM should be dereferencing the page->mapping of a hugetlbfs page as its page cache is not on the LRU. This patch fixes the problem with the test case described in the bugzilla. [akpm@linux-foundation.org: mel cant spel] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Darren Hart <darren@dvhart.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23Cleanup generic block based fiemapJosef Bacik
This cleans up a few of the complaints of __generic_block_fiemap. I've fixed all the typing stuff, used inline functions instead of macros, gotten rid of a couple of variables, and made sure the size and block requests are all block aligned. It also fixes a problem where sometimes FIEMAP_EXTENT_LAST wasn't being set properly. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: ohci: wait for local CSR lock access to finish firewire: ohci: prevent aliasing of locally handled register addresses firewire: core: fw_iso_resource_manage: return -EBUSY when out of resources firewire: core: fix retries calculation in iso manage_channel() firewire: cdev: fix cut+paste mistake in disclaimer
2010-04-22NFS: Fix an unstable write data integrity raceTrond Myklebust
Commit 2c61be0a9478258f77b66208a0c4b1f5f8161c3c (NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible) exposed a race on file close. In order to ensure correct close-to-open behaviour, we want to wait for all outstanding background commit operations to complete. This patch adds an inode flag that indicates if a commit operation is under way, and provides a mechanism to allow ->write_inode() to wait for its completion if this is a data integrity flush. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22smbfs: add bdi backing to mount sessionJens Axboe
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22ncpfs: add bdi backing to mount sessionJens Axboe
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22coda: add bdi backing to mount sessionJens Axboe
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22bdi: add helper function for doing init and register of a bdi for a file systemJens Axboe
Pretty trivial helper, just sets up the bdi and registers it. An atomic sequence count is used to ensure that the registered sysfs names are unique. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6: mc13783-regulator: fix a memory leak in mc13783_regulator_remove regulator: Let drivers know when they use the stub API
2010-04-20KVM: Increase NR_IOBUS_DEVS limit to 200Sridhar Samudrala
This patch increases the current hardcoded limit of NR_IOBUS_DEVS from 6 to 200. We are hitting this limit when creating a guest with more than 1 virtio-net device using vhost-net backend. Each virtio-net device requires 2 such devices to service notifications from rx/tx queues. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-20KVM: fix the handling of dirty bitmaps to avoid overflowsTakuya Yoshikawa
Int is not long enough to store the size of a dirty bitmap. This patch fixes this problem with the introduction of a wrapper function to calculate the sizes of dirty bitmaps. Note: in mark_page_dirty(), we have to consider the fact that __set_bit() takes the offset as int, not long. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-04-19Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Make RCU lockdep check the lockdep_recursion variable rcu: Update docs for rcu_access_pointer and rcu_dereference_protected rcu: Better explain the condition parameter of rcu_dereference_check() rcu: Add rcu_access_pointer and rcu_dereference_protected
2010-04-19regulator: Let drivers know when they use the stub APIJean Delvare
Have the stub variant of regulator_get() return NULL, so that drivers can (but still don't have to) handle this case specifically. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Jerome Oufella <jerome.oufella@savoirfairelinux.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-04-19rcu: Make RCU lockdep check the lockdep_recursion variablePaul E. McKenney
The lockdep facility temporarily disables lockdep checking by incrementing the current->lockdep_recursion variable. Such disabling happens in NMIs and in other situations where lockdep might expect to recurse on itself. This patch therefore checks current->lockdep_recursion, disabling RCU lockdep splats when this variable is non-zero. In addition, this patch removes the "likely()", as suggested by Lai Jiangshan. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Reported-by: David Miller <davem@davemloft.net> Tested-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: eric.dumazet@gmail.com LKML-Reference: <20100415195039.GA22623@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-15firewire: cdev: fix cut+paste mistake in disclaimerStefan Richter
This was supposed to be generic "authors or copyright holders"; I mistakenly picked up text from a wrong file. Reported-by: Daniel K. <dk@uw.no> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: cdev: change license of exported header files to MIT license firewire: cdev: comment fixlet firewire: cdev: iso packet documentation firewire: cdev: fix information leak firewire: cdev: require quadlet-aligned headers for transmit packets firewire: cdev: disallow receive packets without header
2010-04-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: wacom - switch mode upon system resume Revert "Input: wacom - merge out and in prox events" Input: matrix_keypad - allow platform to disable key autorepeat Input: ALPS - add signature for HP Pavilion dm3 laptops Input: i8042 - spelling fix Input: sparse-keymap - implement safer freeing of the keymap Input: update the status of the Multitouch X driver project Input: clarify the no-finger event in multitouch protocol Input: bcm5974 - retract efi-broken suspend_resume Input: sparse-keymap - free the right keymap on error
2010-04-15firewire: cdev: change license of exported header files to MIT licenseStefan Richter
Among else, this allows projects like libdc1394 to carry copies of the ABI related header files without them or distributors having to worry about effects on the project's overall license terms. Switch to MIT license as suggested by Kristian. Also update the year in the copyright statement according to source history. Cc: Jay Fenlason <fenlason@redhat.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
2010-04-14rcu: Better explain the condition parameter of rcu_dereference_check()David Howells
Better explain the condition parameter of rcu_dereference_check() that describes the conditions under which the dereference is permitted to take place (and incorporate Yong Zhang's suggestion). This condition is only checked under lockdep proving. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: eric.dumazet@gmail.com LKML-Reference: <1270852752-25278-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-14rcu: Add rcu_access_pointer and rcu_dereference_protectedPaul E. McKenney
This patch adds variants of rcu_dereference() that handle situations where the RCU-protected data structure cannot change, perhaps due to our holding the update-side lock, or where the RCU-protected pointer is only to be fetched, not dereferenced. These are needed due to some performance concerns with using rcu_dereference() where it is not required, aside from the need for lockdep/sparse checking. The new rcu_access_pointer() primitive is for the case where the pointer is be fetch and not dereferenced. This primitive may be used without protection, RCU or otherwise, due to the fact that it uses ACCESS_ONCE(). The new rcu_dereference_protected() primitive is for the case where updates are prevented, for example, due to holding the update-side lock. This primitive does neither ACCESS_ONCE() nor smp_read_barrier_depends(), so can only be used when updates are somehow prevented. Suggested-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: eric.dumazet@gmail.com LKML-Reference: <1270852752-25278-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-12NFSv4: fix delegated lockingTrond Myklebust
Arnaud Giersch reports that NFSv4 locking is broken when we hold a delegation since commit 8e469ebd6dc32cbaf620e134d79f740bf0ebab79 (NFSv4: Don't allow posix locking against servers that don't support it). According to Arnaud, the lock succeeds the first time he opens the file (since we cannot do a delegated open) but then fails after we start using delegated opens. The following patch fixes it by ensuring that locking behaviour is governed by a per-filesystem capability flag that is initially set, but gets cleared if the server ever returns an OPEN without the NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set. Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-04-10firewire: cdev: comment fixletStefan Richter
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10firewire: cdev: iso packet documentationClemens Ladisch
Add the missing documentation for iso packets. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits) cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch loop: Update mtime when writing using aops block: expose the statistics in blkio.time and blkio.sectors for the root cgroup backing-dev: Handle class_create() failure Block: Fix block/elevator.c elevator_get() off-by-one error drbd: lc_element_by_index() never returns NULL cciss: unlock on error path cfq-iosched: Do not merge queues of BE and IDLE classes cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging i2o: Remove the dangerous kobj_to_i2o_device macro block: remove 16 bytes of padding from struct request on 64bits cfq-iosched: fix a kbuild regression block: make CONFIG_BLK_CGROUP visible Remove GENHD_FL_DRIVERFS block: Export max number of segments and max segment size in sysfs block: Finalize conversion of block limits functions block: Fix overrun in lcm() and move it to lib vfs: improve writeback_inodes_wb() paride: fix off-by-one test drbd: fix al-to-on-disk-bitmap for 4k logical_block_size ...
2010-04-09radix_tree_tag_get() is not as safe as the docs make out [ver #2]David Howells
radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set() or radix_tree_tag_clear(). The problem is that the double tag_get() in radix_tree_tag_get(): if (!tag_get(node, tag, offset)) saw_unset_tag = 1; if (height == 1) { int ret = tag_get(node, tag, offset); may see the value change due to the action of set/clear. RCU is no protection against this as no pointers are being changed, no nodes are being replaced according to a COW protocol - set/clear alter the node directly. The documentation in linux/radix-tree.h, however, says that radix_tree_tag_get() is an exception to the rule that "any function modifying the tree or tags (...) must exclude other modifications, and exclude any functions reading the tree". The problem is that the next statement in radix_tree_tag_get() checks that the tag doesn't vary over time: BUG_ON(ret && saw_unset_tag); This has been seen happening in FS-Cache: https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various comments that the value of the tag may change whilst the RCU read lock is held, and thus that the return value of radix_tree_tag_get() may not be relied upon unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from running concurrently with it. Reported-by: Romain DEGEZ <romain.degez@smartjog.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09slab: Generify kernel pointer validationPekka Enberg
As suggested by Linus, introduce a kern_ptr_validate() helper that does some sanity checks to make sure a pointer is a valid kernel pointer. This is a preparational step for fixing SLUB kmem_ptr_validate(). Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Matt Mackall <mpm@selenic.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-08libata: Fix accesses at LBA28 boundary (old bug, but nasty) (v2)Mark Lord
Most drives from Seagate, Hitachi, and possibly other brands, do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1). So instead use LBA48 for such accesses. This bug could bite a lot of systems, especially when the user has taken care to align partitions to 4KB boundaries. On misaligned systems, it is less likely to be encountered, since a 4KB read would end at 0x10000000 rather than at 0x0fffffff. Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>