user/sven/linux.git/include/linux, branch v3.0.11

nfs: when attempting to open a directory, fall back on normal lookup (try #5)

2011-11-26T17:09:59Z

commit 1788ea6e3b2a58cf4fb00206e362d9caff8d86a7 upstream. commit d953126 changed how nfs_atomic_lookup handles an -EISDIR return from an OPEN call. Prior to that patch, that caused the client to fall back to doing a normal lookup. When that patch went in, the code began returning that error to userspace. The d_revalidate codepath however never had the corresponding change, so it was still possible to end up with a NULL ctx->state pointer after that. That patch caused a regression. When we attempt to open a directory that does not have a cached dentry, that open now errors out with EISDIR. If you attempt the same open with a cached dentry, it will succeed. Fix this by reverting the change in nfs_atomic_lookup and allowing attempts to open directories to fall back to a normal lookup Also, add a NFSv4-specific f_ops->open routine that just returns -ENOTDIR. This should never be called if things are working properly, but if it ever is, then the dprintk may help in debugging. To facilitate this, a new file_operations field is also added to the nfs_rpc_ops struct. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

thp: share get_huge_page_tail()

2011-11-11T17:36:48Z

commit b35a35b556f5e6b7993ad0baf20173e75c09ce8c upstream. This avoids duplicating the function in every arch gup_fast. Signed-off-by: Andrea Arcangeli Cc: Peter Zijlstra Cc: Hugh Dickins Cc: Johannes Weiner Cc: Rik van Riel Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Benjamin Herrenschmidt Cc: David Gibson Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ext2,ext3,ext4: don't inherit APPEND_FL or IMMUTABLE_FL for new inodes

2011-11-11T17:36:32Z

commit 1cd9f0976aa4606db8d6e3dc3edd0aca8019372a upstream. This doesn't make much sense, and it exposes a bug in the kernel where attempts to create a new file in an append-only directory using O_CREAT will fail (but still leave a zero-length file). This was discovered when xfstests #79 was generalized so it could run on all file systems. Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

mm: thp: tail page refcounting fix

2011-11-11T17:36:29Z

commit 70b50f94f1644e2aa7cb374819cfd93f3c28d725 upstream. Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: Andrea Arcangeli Reported-by: Michel Lespinasse Reviewed-by: Michel Lespinasse Reviewed-by: Minchan Kim Cc: Peter Zijlstra Cc: Hugh Dickins Cc: Johannes Weiner Cc: Rik van Riel Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Benjamin Herrenschmidt Cc: David Gibson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

vfs pathname lookup: Add LOOKUP_AUTOMOUNT flag

2011-11-11T17:36:23Z

Since we've now turned around and made LOOKUP_FOLLOW *not* force an automount, we want to add the ability to force an automount event on lookup even if we don't happen to have one of the other flags that force it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..) Most cases will never want to use this, since you'd normally want to delay automounting as long as possible, which usually implies LOOKUP_OPEN (when we open a file or directory, we really cannot avoid the automount any more). But Trond argued sufficiently forcefully that at a minimum bind mounting a file and quotactl will want to force the automount lookup. Some other cases (like nfs_follow_remote_path()) could use it too, although LOOKUP_DIRECTORY would work there as well. This commit just adds the flag and logic, no users yet, though. It also doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and was made irrelevant by the same change that made us not follow on LOOKUP_FOLLOW. Cc: Trond Myklebust Cc: Ian Kent Cc: Jeff Layton Cc: Miklos Szeredi Cc: David Howells Cc: Al Viro Signed-off-by: Linus Torvalds Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

readlinkat: ensure we return ENOENT for the empty pathname for normal lookups

2011-11-11T17:36:19Z

commit 1fa1e7f615f4d3ae436fa319af6e4eebdd4026a8 upstream. Since the commit below which added O_PATH support to the *at() calls, the error return for readlink/readlinkat for the empty pathname has switched from ENOENT to EINVAL: commit 65cfc6722361570bfe255698d9cd4dccaf47570d Author: Al Viro Date: Sun Mar 13 15:56:26 2011 -0400 readlinkat(), fchownat() and fstatat() with empty relative pathnames This is both unexpected for userspace and makes readlink/readlinkat inconsistant with all other interfaces; and inconsistant with our stated return for these pathnames. As the readlinkat call does not have a flags parameter we cannot use the AT_EMPTY_PATH approach used in the other calls. Therefore expose whether the original path is infact entry via a new user_path_at_empty() path lookup function. Use this to determine whether to default to EINVAL or ENOENT for failures. Addresses http://bugs.launchpad.net/bugs/817187 [akpm@linux-foundation.org: remove unused getname_flags()] Signed-off-by: Andy Whitcroft Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman

mm: avoid null pointer access in vm_struct via /proc/vmallocinfo

2011-11-11T17:36:18Z

commit f5252e009d5b87071a919221e4f6624184005368 upstream. The /proc/vmallocinfo shows information about vmalloc allocations in vmlist that is a linklist of vm_struct. It, however, may access pages field of vm_struct where a page was not allocated. This results in a null pointer access and leads to a kernel panic. Why this happens: In __vmalloc_node_range() called from vmalloc(), newly allocated vm_struct is added to vmlist at __get_vm_area_node() and then, some fields of vm_struct such as nr_pages and pages are set at __vmalloc_area_node(). In other words, it is added to vmlist before it is fully initialized. At the same time, when the /proc/vmallocinfo is read, it accesses the pages field of vm_struct according to the nr_pages field at show_numa_info(). Thus, a null pointer access happens. The patch adds the newly allocated vm_struct to the vmlist *after* it is fully initialized. So, it can avoid accessing the pages field with unallocated page when show_numa_info() is called. Signed-off-by: Mitsuo Hayasaka Cc: Andrew Morton Cc: David Rientjes Cc: Namhyung Kim Cc: "Paul E. McKenney" Cc: Jeremy Fitzhardinge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

io-mapping: ensure io_mapping_map_atomic _is_ atomic

2011-11-11T17:36:00Z

commit 24dd85ff723f142093f44244764b9b5c152235b8 upstream. For the !HAVE_ATOMIC_IOMAP case the stub functions did not call pagefault_disable/_enable. The i915 driver relies on the map actually being atomic, otherwise it can deadlock with it's own pagefault handler in the gtt pwrite fastpath. This is exercised by gem_mmap_gtt from the intel-gpu-toosl gem testsuite. v2: Chris Wilson noted the lack of an include. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38115 Signed-off-by: Daniel Vetter Reviewed-by: Chris Wilson Signed-off-by: Keith Packard Signed-off-by: Greg Kroah-Hartman

genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier

2011-11-11T17:35:54Z

commit 9bab0b7fbaceec47d32db51cd9e59c82fb071f5a upstream. This adds a mechanism to resume selected IRQs during syscore_resume instead of dpm_resume_noirq. Under Xen we need to resume IRQs associated with IPIs early enough that the resched IPI is unmasked and we can therefore schedule ourselves out of the stop_machine where the suspend/resume takes place. This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME". Signed-off-by: Ian Campbell Cc: Rafael J. Wysocki Cc: Jeremy Fitzhardinge Cc: xen-devel Cc: Konrad Rzeszutek Wilk Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

time: Change jiffies_to_clock_t() argument type to unsigned long

2011-11-11T17:35:52Z

commit cbbc719fccdb8cbd87350a05c0d33167c9b79365 upstream. The parameter's origin type is long. On an i386 architecture, it can easily be larger than 0x80000000, causing this function to convert it to a sign-extended u64 type. Change the type to unsigned long so we get the correct result. Signed-off-by: hank Cc: John Stultz [ build fix ] Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman