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* dirty page balancing: Get rid of broken unmapped_ratio logicLinus Torvalds2007-11-151-8/+0
| | | | | | | | | | | | | | | | | | | | This code harks back to the days when we didn't count dirty mapped pages, which led us to try to balance the number of dirty unmapped pages by how much unmapped memory there was in the system. That makes no sense any more, since now the dirty counts include the mapped pages. Not to mention that the math doesn't work with HIGHMEM machines anyway, and causes the unmapped_ratio to potentially turn negative (which we do catch thanks to clamping it at a minimum value, but I mention that as an indication of how broken the code is). The code also was written at a time when the default dirty ratio was much larger, and the unmapped_ratio logic effectively capped that large dirty ratio a bit. Again, we've since lowered the dirty ratio rather aggressively, further lessening the point of that code. Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slob: fix memory corruptionNick Piggin2007-11-151-1/+2
| | | | | | | | | | | | | | | | | | Previously, it would be possible for prev->next to point to &free_slob_pages, and thus we would try to move a list onto itself, and bad things would happen. It seems a bit hairy to be doing list operations with the list marker as an entry, rather than a head, but... this resolves the following crash: http://bugzilla.kernel.org/show_bug.cgi?id=9379 Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Swap delay accounting, include lock_page() delaysBalbir Singh2007-11-141-1/+1
| | | | | | | | | | The delay incurred in lock_page() should also be accounted in swap delay accounting Reported-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmstat: fix section mismatch warningRandy Dunlap2007-11-141-1/+1
| | | | | | | | | | | | Mark start_cpu_timer() as __cpuinit instead of __devinit. Fixes this section warning: WARNING: vmlinux.o(.text+0x60e53): Section mismatch: reference to .init.text:start_cpu_timer (between 'vmstat_cpuup_callback' and 'vmstat_show') Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix mm/util.c:krealloc()Adrian Bunk2007-11-141-2/+2
| | | | | | | | | | | | | | | Commit ef8b4520bd9f8294ffce9abd6158085bde5dc902 added one NULL check for "p" in krealloc(), but that doesn't seem to be enough since there doesn't seem to be any guarantee that memcpy(ret, NULL, 0) works (spotted by the Coverity checker). For making it clearer what happens this patch also removes the pointless min(). Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: fix i_blocks accountingKen Chen2007-11-141-0/+10
| | | | | | | | | | | | | For administrative purpose, we want to query actual block usage for hugetlbfs file via fstat. Currently, hugetlbfs always return 0. Fix that up since kernel already has all the information to track it properly. Signed-off-by: Ken Chen <kenchen@google.com> Acked-by: Adam Litke <agl@us.ibm.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: make a function staticAdrian Bunk2007-11-141-1/+1
| | | | | | | | | return_unused_surplus_pages() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: enforce quotas during reservation for shared mappingsAdam Litke2007-11-141-10/+13
| | | | | | | | | | | | | | | | | | | When a MAP_SHARED mmap of a hugetlbfs file succeeds, huge pages are reserved to guarantee no problems will occur later when instantiating pages. If quotas are in force, page instantiation could fail due to a race with another process or an oversized (but approved) shared mapping. To prevent these scenarios, debit the quota for the full reservation amount up front and credit the unused quota when the reservation is released. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Ken Chen <kenchen@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: allow bulk updating in hugetlb_*_quota()Adam Litke2007-11-141-2/+2
| | | | | | | | | | | | | | | Add a second parameter 'delta' to hugetlb_get_quota and hugetlb_put_quota to allow bulk updating of the sbinfo->free_blocks counter. This will be used by the next patch in the series. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Ken Chen <kenchen@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: debit quota in alloc_huge_pageAdam Litke2007-11-141-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | Now that quota is credited by free_huge_page(), calls to hugetlb_get_quota() seem out of place. The alloc/free API is unbalanced because we handle the hugetlb_put_quota() but expect the caller to open-code hugetlb_get_quota(). Move the get inside alloc_huge_page to clean up this disparity. This patch has been kept apart from the previous patch because of the somewhat dodgy ERR_PTR() use herein. Moving the quota logic means that alloc_huge_page() has two failure modes. Quota failure must result in a SIGBUS while a standard allocation failure is OOM. Unfortunately, ERR_PTR() doesn't like the small positive errnos we have in VM_FAULT_* so they must be negated before they are used. Does anyone take issue with the way I am using PTR_ERR. If so, what are your thoughts on how to clean this up (without needing an if,else if,else block at each alloc_huge_page() callsite)? Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Ken Chen <kenchen@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: fix quota management for private mappingsAdam Litke2007-11-141-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hugetlbfs quota management system was never taught to handle MAP_PRIVATE mappings when that support was added. Currently, quota is debited at page instantiation and credited at file truncation. This approach works correctly for shared pages but is incomplete for private pages. In addition to hugetlb_no_page(), private pages can be instantiated by hugetlb_cow(); but this function does not respect quotas. Private huge pages are treated very much like normal, anonymous pages. They are not "backed" by the hugetlbfs file and are not stored in the mapping's radix tree. This means that private pages are invisible to truncate_hugepages() so that function will not credit the quota. This patch (based on a prototype provided by Ken Chen) moves quota crediting for all pages into free_huge_page(). page->private is used to store a pointer to the mapping to which this page belongs. This is used to credit quota on the appropriate hugetlbfs instance. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Ken Chen <kenchen@google.com> Cc: Ken Chen <kenchen@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: split alloc_huge_page into private and shared componentsAdam Litke2007-11-141-19/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hugetlbfs implements a quota system which can limit the amount of memory that can be used by the filesystem. Before allocating a new huge page for a file, the quota is checked and debited. The quota is then credited when truncating the file. I found a few bugs in the code for both MAP_PRIVATE and MAP_SHARED mappings. Before detailing the problems and my proposed solutions, we should agree on a definition of quotas that properly addresses both private and shared pages. Since the purpose of quotas is to limit total memory consumption on a per-filesystem basis, I argue that all pages allocated by the fs (private and shared) should be charged against quota. Private Mappings ================ The current code will debit quota for private pages sometimes, but will never credit it. At a minimum, this causes a leak in the quota accounting which renders the accounting essentially useless as it is. Shared pages have a one to one mapping with a hugetlbfs file and are easy to account by debiting on allocation and crediting on truncate. Private pages are anonymous in nature and have a many to one relationship with their hugetlbfs files (due to copy on write). Because private pages are not indexed by the mapping's radix tree, thier quota cannot be credited at file truncation time. Crediting must be done when the page is unmapped and freed. Shared Pages ============ I discovered an issue concerning the interaction between the MAP_SHARED reservation system and quotas. Since quota is not checked until page instantiation, an over-quota mmap/reservation will initially succeed. When instantiating the first over-quota page, the program will receive SIGBUS. This is inconsistent since the reservation is supposed to be a guarantee. The solution is to debit the full amount of quota at reservation time and credit the unused portion when the reservation is released. This patch series brings quotas back in line by making the following modifications: * Private pages - Debit quota in alloc_huge_page() - Credit quota in free_huge_page() * Shared pages - Debit quota for entire reservation at mmap time - Credit quota for instantiated pages in free_huge_page() - Credit quota for unused reservation at munmap time This patch: The shared page reservation and dynamic pool resizing features have made the allocation of private vs. shared huge pages quite different. By splitting out the private/shared-specific portions of the process into their own functions, readability is greatly improved. alloc_huge_page now calls the proper helper and performs common operations. [akpm@linux-foundation.org: coding-style cleanups] Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Ken Chen <kenchen@google.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: follow_hugetlb_page() for write accessAdam Litke2007-11-142-3/+4
| | | | | | | | | | | | | | | | | | | | | | When calling get_user_pages(), a write flag is passed in by the caller to indicate if write access is required on the faulted-in pages. Currently, follow_hugetlb_page() ignores this flag and always faults pages for read-only access. This can cause data corruption because a device driver that calls get_user_pages() with write set will not expect COW faults to occur on the returned pages. This patch passes the write flag down to follow_hugetlb_page() and makes sure hugetlb_fault() is called with the right write_access parameter. [ezk@cs.sunysb.edu: build fix] Signed-off-by: Adam Litke <agl@us.ibm.com> Reviewed-by: Ken Chen <kenchen@google.com> Cc: David Gibson <hermes@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add IORESOUCE_BUSY flag for System RAMYasunori Goto2007-11-141-1/+1
| | | | | | | | | | | | | | | | | | | | | i386 and x86-64 registers System RAM as IORESOURCE_MEM | IORESOURCE_BUSY. But ia64 registers it as IORESOURCE_MEM only. In addition, memory hotplug code registers new memory as IORESOURCE_MEM too. This difference causes a failure of memory unplug of x86-64. This patch fixes it. This patch adds IORESOURCE_BUSY to avoid potential overlap mapping by PCI device. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Cc: Luck, Tony" <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: speed up writeback ramp-up on clean systemsPeter Zijlstra2007-11-141-2/+17
| | | | | | | | | | | | We allow violation of bdi limits if there is a lot of room on the system. Once we hit half the total limit we start enforcing bdi limits and bdi ramp-up should happen. Doing it this way avoids many small writeouts on an otherwise idle system and should also speed up the ramp-up. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotremove: unset migrate type "ISOLATE" after removalKAMEZAWA Hiroyuki2007-11-142-5/+5
| | | | | | | | | | | | | | | We should unset migrate type "ISOLATE" when we successfully removed memory. But current code has BUG and cannot works well. This patch also includes bugfix? to change get_pageblock_flags to get_pageblock_migratetype(). Thanks to Badari Pulavarty for finding this. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Migration: find correct vma in new_vma_page()Lee Schermerhorn2007-11-142-5/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We hit the BUG_ON() in mm/rmap.c:vma_address() when trying to migrate via mbind(MPOL_MF_MOVE) a non-anon region that spans multiple vmas. For anon-regions, we just fail to migrate any pages beyond the 1st vma in the range. This occurs because do_mbind() collects a list of pages to migrate by calling check_range(). check_range() walks the task's mm, spanning vmas as necessary, to collect the migratable pages into a list. Then, do_mbind() calls migrate_pages() passing the list of pages, a function to allocate new pages based on vma policy [new_vma_page()], and a pointer to the first vma of the range. For each page in the list, new_vma_page() calls page_address_in_vma() passing the page and the vma [first in range] to obtain the address to get for alloc_page_vma(). The page address is needed to get interleaving policy correct. If the pages in the list come from multiple vmas, eventually, new_page_address() will pass that page to page_address_in_vma() with the incorrect vma. For !PageAnon pages, this will result in a bug check in rmap.c:vma_address(). For anon pages, vma_address() will just return EFAULT and fail the migration. This patch modifies new_vma_page() to check the return value from page_address_in_vma(). If the return value is EFAULT, new_vma_page() searchs forward via vm_next for the vma that maps the page--i.e., that does not return EFAULT. This assumes that the pages in the list handed to migrate_pages() is in address order. This is currently case. The patch documents this assumption in a new comment block for new_vma_page(). If new_vma_page() cannot locate the vma mapping the page in a forward search in the mm, it will pass a NULL vma to alloc_page_vma(). This will result in the allocation using the task policy, if any, else system default policy. This situation is unlikely, but the patch documents this behavior with a comment. Note, this patch results in restarting from the first vma in a multi-vma range each time new_vma_page() is called. If this is not acceptable, we can make the vma argument a pointer, both in new_vma_page() and it's caller unmap_and_move() so that the value held by the loop in migrate_pages() always passes down the last vma in which a page was found. This will require changes to all new_page_t functions passed to migrate_pages(). Is this necessary? For this patch to work, we can't bug check in vma_address() for pages outside the argument vma. This patch removes the BUG_ON(). All other callers [besides new_vma_page()] already check the return status. Tested on x86_64, 4 node NUMA platform. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slab: fix typo in allocation failure handlingAkinobu Mita2007-11-141-1/+1
| | | | | | | | | | This patch fixes wrong array index in allocation failure handling. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "Bias the placement of kernel pages at lower PFNs"Linus Torvalds2007-11-121-20/+0
| | | | | | | | | | | | | | This reverts commit 5adc5be7cd1bcef6bb64f5255d2a33f20a3cf5be. Alexey Dobriyan reports that it causes huge slowdowns under some loads, in his case a "mkfs.ext2" on a 30G partition. With the placement bias, the mkfs took over four minutes, with it reverted it's back to about ten seconds for Alexey. Reported-and-tested-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: killed the unused "end" variableDenis Cheng2007-11-121-2/+0
| | | | | | | Since the macro "for_each_object" introduced, the "end" variable becomes unused anymore. Signed-off-by: Denis Cheng <crquan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' of ↵Linus Torvalds2007-11-051-1/+0
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: lguest: tidy up documentation kernel/futex.c: make 3 functions static unexport access_process_vm lguest: make async_hcall() static
| * unexport access_process_vmAdrian Bunk2007-11-051-1/+0
| | | | | | | | | | | | | | This patch removes the no longer used EXPORT_SYMBOL_GPL(access_process_vm). Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | SLUB: Fix memory leak by not reusing cpu_slabChristoph Lameter2007-11-051-19/+1
|/ | | | | | | | | | | | | | | | | | Fix the memory leak that may occur when we attempt to reuse a cpu_slab that was allocated while we reenabled interrupts in order to be able to grow a slab cache. The per cpu freelist may contain objects and in that situation we may overwrite the per cpu freelist pointer loosing objects. This only occurs if we find that the concurrently allocated slab fits our allocation needs. If we simply always deactivate the slab then the freelist will be properly reintegrated and the memory leak will go away. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove broken ptrace() special-case code from file mappingLinus Torvalds2007-10-311-11/+2
| | | | | | | | | | | | | | | | | | | | | | | | The kernel has for random historical reasons allowed ptrace() accesses to access (and insert) pages into the page cache above the size of the file. However, Nick broke that by mistake when doing the new fault handling in commit 54cb8821de07f2ffcd28c380ce9b93d5784b40d7 ("mm: merge populate and nopage into fault (fixes nonlinear)". The breakage caused a hang with gdb when trying to access the invalid page. The ptrace "feature" really isn't worth resurrecting, since it really is wrong both from a portability _and_ from an internal page cache validity standpoint. So this removes those old broken remnants, and fixes the ptrace() hang in the process. Noticed and bisected by Duane Griffin, who also supplied a test-case (quoth Nick: "Well that's probably the best bug report I've ever had, thanks Duane!"). Cc: Duane Griffin <duaneg@dghda.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dio: fix cache invalidation after sync writesZach Brown2007-10-301-10/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit commit 65b8291c4000e5f38fc94fb2ca0cb7e8683c8a1b ("dio: invalidate clean pages before dio write") introduced a bug which stopped dio from ever invalidating the page cache after writes. It still invalidated it before writes so most users were fine. Karl Schendel reported ( http://lkml.org/lkml/2007/10/26/481 ) hitting this bug when he had a buffered reader immediately reading file data after an O_DIRECT wirter had written the data. The kernel issued read-ahead beyond the position of the reader which overlapped with the O_DIRECT writer. The failure to invalidate after writes caused the reader to see stale data from the read-ahead. The following patch is originally from Karl. The following commentary is his: The below 3rd try takes on your suggestion of just invalidating no matter what the retval from the direct_IO call. I ran it thru the test-case several times and it has worked every time. The post-invalidate is probably still too early for async-directio, but I don't have a testcase for that; just sync. And, this won't be any worse in the async case. I added a test to the aio-dio-regress repository which mimics Karl's IO pattern. It verifed the bad behaviour and that the patch fixed it. I agree with Karl, this still doesn't help the case where a buffered reader follows an AIO O_DIRECT writer. That will require a bit more work. This gives up on the idea of returning EIO to indicate to userspace that stale data remains if the invalidation failed. Signed-off-by: Zach Brown <zach.brown@oracle.com> Cc: Karl Schendel <kschendel@datallegro.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Leonid Ananiev <leonid.i.ananiev@linux.intel.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix tmpfs BUG and AOP_WRITEPAGE_ACTIVATEHugh Dickins2007-10-301-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible to provoke unionfs (not yet in mainline, though in mm and some distros) to hit shmem_writepage's BUG_ON(page_mapped(page)). I expect it's possible to provoke the 2.6.23 ecryptfs in the same way (but the 2.6.24 ecryptfs no longer calls lower level's ->writepage). This came to light with the recent find that AOP_WRITEPAGE_ACTIVATE could leak from tmpfs via write_cache_pages and unionfs to userspace. There's already a fix (e423003028183df54f039dfda8b58c49e78c89d7 - writeback: don't propagate AOP_WRITEPAGE_ACTIVATE) in the tree for that, and it's okay so far as it goes; but insufficient because it doesn't address the underlying issue, that shmem_writepage expects to be called only by vmscan (relying on backing_dev_info capabilities to prevent the normal writeback path from ever approaching it). That's an increasingly fragile assumption, and ramdisk_writepage (the other source of AOP_WRITEPAGE_ACTIVATEs) is already careful to check wbc->for_reclaim before returning it. Make the same check in shmem_writepage, thereby sidestepping the page_mapped BUG also. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Erez Zadok <ezk@cs.sunysb.edu> Cc: <stable@kernel.org> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/sparse-vmemmap.c: make sure init_mm is includedGlauber de Oliveira Costa2007-10-301-0/+1
| | | | | | | | | | | | | | | mm/sparse-vmemmap.c uses init_mm in some places. However, it is not present in any of the headers currently included in the file. init_mm is defined as extern in sched.h, so we add it to the headers list Up to now, this problem was masked by the fact that functions like set_pte_at() and pmd_populate_kernel() are usually macros that expand to simpler variants that does not use the first parameter at all. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "x86_64: allocate sparsemem memmap above 4G"Linus Torvalds2007-10-291-11/+0
| | | | | | | | | | | | | | | | | | | | | | This reverts commit 2e1c49db4c640b35df13889b86b9d62215ade4b6. First off, testing in Fedora has shown it to cause boot failures, bisected down by Martin Ebourne, and reported by Dave Jobes. So the commit will likely be reverted in the 2.6.23 stable kernels. Secondly, in the 2.6.24 model, x86-64 has now grown support for SPARSEMEM_VMEMMAP, which disables the relevant code anyway, so while the bug is not visible any more, it's become invisible due to the code just being irrelevant and no longer enabled on the only architecture that this ever affected. Reported-by: Dave Jones <davej@redhat.com> Tested-by: Martin Ebourne <fedora@ebourne.me.uk> Cc: Zou Nan hai <nanhai.zou@intel.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NOMMU: mm/nommu.c needs linux/module.hDavid Howells2007-10-291-0/+1
| | | | | | | | mm/nommu.c needs to #include linux/module.h for it to understand EXPORT_*() macros. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2007-10-291-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: compat_ioctl: fix block device compat ioctl regression [BLOCK] Fix bad sharing of tag busy list on queues with shared tag maps Fix a build error when BLOCK=n block: use lock bitops for the tag map. cciss: update copyright notices cfq_get_queue: fix possible NULL pointer access blk_sync_queue() should cancel request_queue->unplug_work cfq_exit_queue() should cancel cfq_data->unplug_work block layer: remove a unused argument of drive_stat_acct()
| * Fix a build error when BLOCK=nEmil Medve2007-10-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm/filemap.c: In function '__filemap_fdatawrite_range': mm/filemap.c:200: error: implicit declaration of function 'mapping_cap_writeback_dirty' This happens when we don't use/have any block devices and a NFS root filesystem is used. mapping_cap_writeback_dirty() is defined in linux/backing-dev.h which used to be provided in mm/filemap.c by linux/blkdev.h until commit f5ff8422bbdd59f8c1f699df248e1b7a11073027 (Fix warnings with !CONFIG_BLOCK). Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | missing atomic_read_long() in slub.cAl Viro2007-10-291-1/+1
|/ | | | | | | nr_slabs is atomic_long_t, not atomic_t Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix mprotect vma_wants_writenotify protHugh Dickins2007-10-232-3/+2
| | | | | | | | | | | | | | | Fix mprotect bug in recent commit 3ed75eb8f1cd89565966599c4f77d2edb086d5b0 (setup vma->vm_page_prot by vm_get_page_prot()): the vma_wants_writenotify case was setting the same prot as when not. Nothing wrong with the use of protection_map[] in mmap_region(), but use vm_get_page_prot() there too in the same ~VM_SHARED way. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Coly Li <coyli@suse.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exportfs: make struct export_operations constChristoph Hellwig2007-10-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Now that nfsd has stopped writing to the find_exported_dentry member we an mark the export_operations const Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Neil Brown <neilb@suse.de> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: <linux-ext4@vger.kernel.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: David Chinner <dgc@sgi.com> Cc: Timothy Shimmin <tes@sgi.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Hugh Dickins <hugh@veritas.com> Cc: Chris Mason <mason@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: "Vladimir V. Saveliev" <vs@namesys.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* shmem: new export opsChristoph Hellwig2007-10-221-22/+13
| | | | | | | | | | | | I'm not sure what people were thinking when adding support to export tmpfs, but here's the conversion anyway: Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Neil Brown <neilb@suse.de> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: make kmem_cache_node for SLUB on memory online avoid panicYasunori Goto2007-10-221-0/+118
| | | | | | | | | | | | | | | | | | | | | | Fix a panic due to access NULL pointer of kmem_cache_node at discard_slab() after memory online. When memory online is called, kmem_cache_nodes are created for all SLUBs for new node whose memory are available. slab_mem_going_online_callback() is called to make kmem_cache_node() in callback of memory online event. If it (or other callbacks) fails, then slab_mem_offline_callback() is called for rollback. In memory offline, slab_mem_going_offline_callback() is called to shrink all slub cache, then slab_mem_offline_callback() is called later. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: locking fix] [akpm@linux-foundation.org: build fix] Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory hotplug: rearrange memory hotplug notifierYasunori Goto2007-10-221-3/+45
| | | | | | | | | | | | | | | | | | | | | | Current memory notifier has some defects yet. (Fortunately, nothing uses it.) This patch is to fix and rearrange for them. - Add information of start_pfn, nr_pages, and node id if node status is changes from/to memoryless node for callback functions. Callbacks can't do anything without those information. - Add notification going-online status. It is necessary for creating per node structure before the node's pages are available. - Move GOING_OFFLINE status notification after page isolation. It is good place for return memory like cache for callback, because returned page is not used again. - Make CANCEL events for rollingback when error occurs. - Delete MEM_MAPPING_INVALID notification. It will be not used. - Fix compile error of (un)register_memory_notifier(). Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom_kill bugAl Viro2007-10-201-1/+1
| | | | | | | Wrong order of arguments Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* small documentation fixesPhilipp Marek2007-10-201-1/+1
| | | | Signed-off-by: Adrian Bunk <bunk@kernel.org>
* Typo fixes retrun -> returnGabriel Craciunescu2007-10-201-1/+1
| | | | | | | Typo fixes retrun -> return Signed-off-by: Gabriel Craciunescu <nix.or.die@googlemail.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* spelling fixes: mm/Simon Arlott2007-10-2011-18/+18
| | | | | | | Spelling fixes in mm/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* Explain clearly why kmalloc() can't use __GFP_HIGHMEM.Robert P. J. Day2007-10-191-1/+2
| | | | | | | | Fix the wishy-washy comment to clearly explain why kmalloc() can't use the __GFP_HIGHMEM zone modifier. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* Use helpers to obtain task pid in printksPavel Emelyanov2007-10-191-2/+3
| | | | | | | | | | | | | | | | The task_struct->pid member is going to be deprecated, so start using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in the kernel. The first thing to start with is the pid, printed to dmesg - in this case we may safely use task_pid_nr(). Besides, printks produce more (much more) than a half of all the explicit pid usage. [akpm@linux-foundation.org: git-drm went and changed lots of stuff] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Isolate some explicit usage of task->tgidPavel Emelyanov2007-10-191-1/+1
| | | | | | | | | | | | | | | | | | | | With pid namespaces this field is now dangerous to use explicitly, so hide it behind the helpers. Also the pid and pgrp fields o task_struct and signal_struct are to be deprecated. Unfortunately this patch cannot be sent right now as this leads to tons of warnings, so start isolating them, and deprecate later. Actually the p->tgid == pid has to be changed to has_group_leader_pid(), but Oleg pointed out that in case of posix cpu timers this is the same, and thread_group_leader() is more preferable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Uninline find_task_by_xxx set of functionsPavel Emelyanov2007-10-192-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: changes to show virtual ids to userPavel Emelyanov2007-10-192-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/oom_kill.c: Use list_for_each_entry instead of list_for_eachMatthias Kaehlcke2007-10-191-3/+1
| | | | | | | | | | mm/oom_kill.c: Convert list_for_each to list_for_each_entry in oom_kill_process() Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: define is_global_init() and is_container_init()Serge E. Hallyn2007-10-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is_init() is an ambiguous name for the pid==1 check. Split it into is_global_init() and is_container_init(). A cgroup init has it's tsk->pid == 1. A global init also has it's tsk->pid == 1 and it's active pid namespace is the init_pid_ns. But rather than check the active pid namespace, compare the task structure with 'init_pid_ns.child_reaper', which is initialized during boot to the /sbin/init process and never changes. Changelog: 2.6.22-rc4-mm2-pidns1: - Use 'init_pid_ns.child_reaper' to determine if a given task is the global init (/sbin/init) process. This would improve performance and remove dependence on the task_pid(). 2.6.21-mm2-pidns2: - [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc, ppc,avr32}/traps.c for the _exception() call to is_global_init(). This way, we kill only the cgroup if the cgroup's init has a bug rather than force a kernel panic. [akpm@linux-foundation.org: fix comment] [sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c] [bunk@stusta.de: kernel/pid.c: remove unused exports] [sukadev@us.ibm.com: Fix capability.c to work with threaded init] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Acked-by: Pavel Emelianov <xemul@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Herbert Poetzel <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Task Control Groups: make cpusets a client of cgroupsPaul Menage2007-10-191-2/+0
| | | | | | | | | | | | | | | | | | | | | | Remove the filesystem support logic from the cpusets system and makes cpusets a cgroup subsystem The "cpuset" filesystem becomes a dummy filesystem; attempts to mount it get passed through to the cgroup filesystem with the appropriate options to emulate the old cpuset filesystem behaviour. Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel-api docbook: fix content problemsRandy Dunlap2007-10-191-1/+1
| | | | | | | | | | | | | | | | | Fix kernel-api docbook contents problems. docproc: linux-2.6.23-git13/include/asm-x86/unaligned_32.h: No such file or directory Warning(linux-2.6.23-git13//include/linux/list.h:482): bad line: of list entry Warning(linux-2.6.23-git13//mm/filemap.c:864): No description found for parameter 'ra' Warning(linux-2.6.23-git13//block/ll_rw_blk.c:3760): No description found for parameter 'req' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'private' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'cdev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: WU Fengguang <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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