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2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-24mm/shmem.c: fix unlikely() test of info->seals to test only for WRITE and GROWSteven Rostedt (VMware)
Running my likely/unlikely profiler, I discovered that the test in shmem_write_begin() that tests for info->seals as unlikely, is always incorrect. This is because shmem_get_inode() sets info->seals to have F_SEAL_SEAL set by default, and it is unlikely to be cleared when shmem_write_begin() is called. Thus, the if statement is very likely. But as the if statement block only cares about F_SEAL_WRITE and F_SEAL_GROW, change the test to only test those two bits. Link: http://lkml.kernel.org/r/20170203105656.7aec6237@gandalf.local.home Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: avoid leaking blocks and used blocks in UFFDIO_COPYAndrea Arcangeli
If the atomic copy_user fails because of a real dangling userland pointer, we won't go back into the shmem method, so when the method returns it must not leave anything charged up, except the page itself. Link: http://lkml.kernel.org/r/20161216144821.5183-37-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: avoid a lockup resulting from corrupted page->flagsAndrea Arcangeli
Use the non atomic version of __SetPageUptodate while the page is still private and not visible to lookup operations. Using the non atomic version after the page is already visible to lookups is unsafe as there would be concurrent lock_page operation modifying the page->flags while it runs. This solves a lockup in find_lock_entry with the userfaultfd_shmem selftest. userfaultfd_shm D14296 691 1 0x00000004 Call Trace: schedule+0x3d/0x90 schedule_timeout+0x228/0x420 io_schedule_timeout+0xa4/0x110 __lock_page+0x12d/0x170 find_lock_entry+0xa4/0x190 shmem_getpage_gfp+0xb9/0xc30 shmem_fault+0x70/0x1c0 __do_fault+0x21/0x150 handle_mm_fault+0xec9/0x1490 __do_page_fault+0x20d/0x520 trace_do_page_fault+0x61/0x270 do_async_page_fault+0x19/0x80 async_page_fault+0x25/0x30 Link: http://lkml.kernel.org/r/20170116180408.12184-2-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: lock the page before adding it to pagecacheAndrea Arcangeli
A VM_BUG_ON triggered on the shmem selftest. Link: http://lkml.kernel.org/r/20161216144821.5183-36-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: add userfaultfd hook for shared memory faultsMike Rapoport
When processing a page fault in shared memory area for not present page, check the VMA determine if faults are to be handled by userfaultfd. If so, delegate the page fault to handle_userfault. Link: http://lkml.kernel.org/r/20161216144821.5183-33-aarcange@redhat.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: add tlbflush.h header for microblazeAndrea Arcangeli
It resolves this build error: All errors (new ones prefixed by >>): mm/shmem.c: In function 'shmem_mcopy_atomic_pte': >> mm/shmem.c:2228:2: error: implicit declaration of function 'update_mmu_cache' [-Werror=implicit-function-declaration] update_mmu_cache(dst_vma, dst_addr, dst_pte); microblaze may have to be also updated to define it in asm/pgtable.h like the other archs, then this header inclusion can be removed. Link: http://lkml.kernel.org/r/20161216144821.5183-31-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: introduce vma_is_shmemMike Rapoport
Currently userfault relies on vma_is_anonymous and vma_is_hugetlb to ensure compatibility of a VMA with userfault. Introduction of vma_is_shmem allows detection if tmpfs backed VMAs, so that they may be used with userfaultfd. Current implementation presumes usage of vma_is_shmem only by slow path routines in userfaultfd, therefore the vma_is_shmem is not made inline to leave the few remaining free bits in vm_flags. Link: http://lkml.kernel.org/r/20161216144821.5183-30-aarcange@redhat.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd supportMike Rapoport
shmem_mcopy_atomic_pte is the low level routine that implements the userfaultfd UFFDIO_COPY command. It is based on the existing mcopy_atomic_pte routine with modifications for shared memory pages. Link: http://lkml.kernel.org/r/20161216144821.5183-29-aarcange@redhat.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22tmpfs: change shmem_mapping() to test shmem_aopsHugh Dickins
Callers of shmem_mapping() are interested in whether the mapping is swap backed - except for uprobes, which is interested in whether it should use shmem_read_mapping_page(). All these callers are better served by a shmem_mapping() which checks for shmem_aops, than the current version which goes through several indirections to find where the inode lives - and has the surprising effect that a private mmap of /dev/zero satisfies both vma_is_anonymous() and shmem_mapping(), when that device node is on devtmpfs. I don't think anything in the tree suffers from that surprise, but it caught me out, and is better fixed. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052148530.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-03shmem: fix sleeping from atomic contextKirill A. Shutemov
Syzkaller fuzzer managed to trigger this: BUG: sleeping function called from invalid context at mm/shmem.c:852 in_atomic(): 1, irqs_disabled(): 0, pid: 529, name: khugepaged 3 locks held by khugepaged/529: #0: (shrinker_rwsem){++++..}, at: [<ffffffff818d7ef1>] shrink_slab.part.59+0x121/0xd30 mm/vmscan.c:451 #1: (&type->s_umount_key#29){++++..}, at: [<ffffffff81a63630>] trylock_super+0x20/0x100 fs/super.c:392 #2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] spin_lock include/linux/spinlock.h:302 [inline] #2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] shmem_unused_huge_shrink+0x28e/0x1490 mm/shmem.c:427 CPU: 2 PID: 529 Comm: khugepaged Not tainted 4.10.0-rc5+ #201 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: shmem_undo_range+0xb20/0x2710 mm/shmem.c:852 shmem_truncate_range+0x27/0xa0 mm/shmem.c:939 shmem_evict_inode+0x35f/0xca0 mm/shmem.c:1030 evict+0x46e/0x980 fs/inode.c:553 iput_final fs/inode.c:1515 [inline] iput+0x589/0xb20 fs/inode.c:1542 shmem_unused_huge_shrink+0xbad/0x1490 mm/shmem.c:446 shmem_unused_huge_scan+0x10c/0x170 mm/shmem.c:512 super_cache_scan+0x376/0x450 fs/super.c:106 do_shrink_slab mm/vmscan.c:378 [inline] shrink_slab.part.59+0x543/0xd30 mm/vmscan.c:481 shrink_slab mm/vmscan.c:2592 [inline] shrink_node+0x2c7/0x870 mm/vmscan.c:2592 shrink_zones mm/vmscan.c:2734 [inline] do_try_to_free_pages+0x369/0xc80 mm/vmscan.c:2776 try_to_free_pages+0x3c6/0x900 mm/vmscan.c:2982 __perform_reclaim mm/page_alloc.c:3301 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:3322 [inline] __alloc_pages_slowpath+0xa24/0x1c30 mm/page_alloc.c:3683 __alloc_pages_nodemask+0x544/0xae0 mm/page_alloc.c:3848 __alloc_pages include/linux/gfp.h:426 [inline] __alloc_pages_node include/linux/gfp.h:439 [inline] khugepaged_alloc_page+0xc2/0x1b0 mm/khugepaged.c:750 collapse_huge_page+0x182/0x1fe0 mm/khugepaged.c:955 khugepaged_scan_pmd+0xfdf/0x12a0 mm/khugepaged.c:1208 khugepaged_scan_mm_slot mm/khugepaged.c:1727 [inline] khugepaged_do_scan mm/khugepaged.c:1808 [inline] khugepaged+0xe9b/0x1590 mm/khugepaged.c:1853 kthread+0x326/0x3f0 kernel/kthread.c:227 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 The iput() from atomic context was a bad idea: if after igrab() somebody else calls iput() and we left with the last inode reference, our iput() would lead to inode eviction and therefore sleeping. This patch should fix the situation. Link: http://lkml.kernel.org/r/20170131093141.GA15899@node.shutemov.name Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-17Merge uncontroversial parts of branch 'readlink' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull partial readlink cleanups from Miklos Szeredi. This is the uncontroversial part of the readlink cleanup patch-set that simplifies the default readlink handling. Miklos and Al are still discussing the rest of the series. * git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: vfs: make generic_readlink() static vfs: remove ".readlink = generic_readlink" assignments vfs: default to generic_readlink() vfs: replace calling i_op->readlink with vfs_readlink() proc/self: use generic_readlink ecryptfs: use vfs_get_link() bad_inode: add missing i_op initializers
2016-12-14radix-tree: delete radix_tree_locate_item()Matthew Wilcox
This rather complicated function can be better implemented as an iterator. It has only one caller, so move the functionality to the only place that needs it. Update the test suite to follow the same pattern. Link: http://lkml.kernel.org/r/1480369871-5271-56-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Konstantin Khlebnikov <koct9i@gmail.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14radix-tree: improve multiorder iteratorsMatthew Wilcox
This fixes several interlinked problems with the iterators in the presence of multiorder entries. 1. radix_tree_iter_next() would only advance by one slot, which would result in the iterators returning the same entry more than once if there were sibling entries. 2. radix_tree_next_slot() could return an internal pointer instead of a user pointer if a tagged multiorder entry was immediately followed by an entry of lower order. 3. radix_tree_next_slot() expanded to a lot more code than it used to when multiorder support was compiled in. And I wasn't comfortable with entry_to_node() being in a header file. Fixing radix_tree_iter_next() for the presence of sibling entries necessarily involves examining the contents of the radix tree, so we now need to pass 'slot' to radix_tree_iter_next(), and we need to change the calling convention so it is called *before* dropping the lock which protects the tree. Also rename it to radix_tree_iter_resume(), as some people thought it was necessary to call radix_tree_iter_next() each time around the loop. radix_tree_next_slot() becomes closer to how it looked before multiorder support was introduced. It only checks to see if the next entry in the chunk is a sibling entry or a pointer to a node; this should be rare enough that handling this case out of line is not a performance impact (and such impact is amortised by the fact that the entry we just processed was a multiorder entry). Also, radix_tree_next_slot() used to force a new chunk lookup for untagged entries, which is more expensive than the out of line sibling entry skipping. Link: http://lkml.kernel.org/r/1480369871-5271-55-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12lib: radix-tree: update callback for changing leaf nodesJohannes Weiner
Support handing __radix_tree_replace() a callback that gets invoked for all leaf nodes that change or get freed as a result of the slot replacement, to assist users tracking nodes with node->private_list. This prepares for putting page cache shadow entries into the radix tree root again and drastically simplifying the shadow tracking. Link: http://lkml.kernel.org/r/20161117193134.GD23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12lib: radix-tree: native accounting of exceptional entriesJohannes Weiner
The way the page cache is sneaking shadow entries of evicted pages into the radix tree past the node entry accounting and tracking them manually in the upper bits of node->count is fraught with problems. These shadow entries are marked in the tree as exceptional entries, which are a native concept to the radix tree. Maintain an explicit counter of exceptional entries in the radix tree node. Subsequent patches will switch shadow entry tracking over to that counter. DAX and shmem are the other users of exceptional entries. Since slot replacements that change the entry type from regular to exceptional must now be accounted, introduce a __radix_tree_replace() function that does replacement and accounting, and switch DAX and shmem over. The increase in radix tree node size is temporary. A followup patch switches the shadow tracking to this new scheme and we'll no longer need the upper bits in node->count and shrink that back to one byte. Link: http://lkml.kernel.org/r/20161117192945.GA23430@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12shmem: fix compilation warnings on unused functionsJérémy Lefaure
Compiling shmem.c with SHMEM and TRANSAPRENT_HUGE_PAGECACHE enabled raises warnings on two unused functions when CONFIG_TMPFS and CONFIG_SYSFS are both disabled: mm/shmem.c:390:20: warning: `shmem_format_huge' defined but not used [-Wunused-function] static const char *shmem_format_huge(int huge) ^~~~~~~~~~~~~~~~~ mm/shmem.c:373:12: warning: `shmem_parse_huge' defined but not used [-Wunused-function] static int shmem_parse_huge(const char *str) ^~~~~~~~~~~~~~~~ A conditional compilation on tmpfs or sysfs removes the warnings. Link: http://lkml.kernel.org/r/20161118055749.11313-1-jeremy.lefaure@lse.epita.fr Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12shmem: avoid maybe-uninitialized warningArnd Bergmann
After enabling -Wmaybe-uninitialized warnings, we get a false-postive warning for shmem: mm/shmem.c: In function `shmem_getpage_gfp': include/linux/spinlock.h:332:21: error: `info' may be used uninitialized in this function [-Werror=maybe-uninitialized] This can be easily avoided, since the correct 'info' pointer is known at the time we first enter the function, so we can simply move the initialization up. Moving it before the first label avoids the warning and lets us remove two later initializations. Note that the function is so hard to read that it not only confuses the compiler, but also most readers and without this patch it could\ easily break if one of the 'goto's changed. Link: https://www.spinics.net/lists/kernel/msg2368133.html Link: http://lkml.kernel.org/r/20161024205725.786455-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-09vfs: remove ".readlink = generic_readlink" assignmentsMiklos Szeredi
If .readlink == NULL implies generic_readlink(). Generated by: to_del="\.readlink.*=.*generic_readlink" for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-06shmem: fix shm fallocate() list corruptionLinus Torvalds
The shmem hole punching with fallocate(FALLOC_FL_PUNCH_HOLE) does not want to race with generating new pages by faulting them in. However, the wait-queue used to delay the page faulting has a serious problem: the wait queue head (in shmem_fallocate()) is allocated on the stack, and the code expects that "wake_up_all()" will make sure that all the queue entries are gone before the stack frame is de-allocated. And that is not at all necessarily the case. Yes, a normal wake-up sequence will remove the wait-queue entry that caused the wakeup (see "autoremove_wake_function()"), but the key wording there is "that caused the wakeup". When there are multiple possible wakeup sources, the wait queue entry may well stay around. And _particularly_ in a page fault path, we may be faulting in new pages from user space while we also have other things going on, and there may well be other pending wakeups. So despite the "wake_up_all()", it's not at all guaranteed that all list entries are removed from the wait queue head on the stack. Fix this by introducing a new wakeup function that removes the list entry unconditionally, even if the target process had already woken up for other reasons. Use that "synchronous" function to set up the waiters in shmem_fault(). This problem has never been seen in the wild afaik, but Dave Jones has reported it on and off while running trinity. We thought we fixed the stack corruption with the blk-mq rq_list locking fix (commit 7fe311302f7d: "blk-mq: update hardware and software queues for sleeping alloc"), but it turns out there was _another_ stack corruptor hiding in the trinity runs. Vegard Nossum (also running trinity) was able to trigger this one fairly consistently, and made us look once again at the shmem code due to the faults often being in that area. Reported-and-tested-by: Vegard Nossum <vegard.nossum@oracle.com>. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11shmem: fix pageflags after swapping DMA32 objectHugh Dickins
If shmem_alloc_page() does not set PageLocked and PageSwapBacked, then shmem_replace_page() needs to do so for itself. Without this, it puts newpage on the wrong lru, re-unlocks the unlocked newpage, and system descends into "Bad page" reports and freeze; or if CONFIG_DEBUG_VM=y, it hits an earlier VM_BUG_ON_PAGE(!PageLocked), depending on config. But shmem_replace_page() is not a common path: it's only called when swapin (or swapoff) finds the page was already read into an unsuitable zone: usually all zones are suitable, but gem objects for a few drm devices (gma500, omapdrm, crestline, broadwater) require zone DMA32 if there's more than 4GB of ram. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1611062003510.11253@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [4.8.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-10Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro
2016-10-10Merge branch 'work.xattr' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check
2016-10-10Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-08Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro
2016-10-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
2016-10-07vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher
These inode operations are no longer used; remove them. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07mm/shmem.c: constify anon_opsRasmus Villemoes
Every other dentry_operations instance is const, and this one might as well be. Link: http://lkml.kernel.org/r/1473890528-7009-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-05switch generic_file_splice_read() to use of ->read_iter()Al Viro
... and kill the ->splice_read() instances that can be switched to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27fs: rename "rename2" i_op to "rename"Miklos Szeredi
Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-24huge tmpfs: fix Committed_AS leakHugh Dickins
Under swapping load on huge tmpfs, /proc/meminfo's Committed_AS grows bigger and bigger: just a cosmetic issue for most users, but disabling for those who run without overcommit (/proc/sys/vm/overcommit_memory 2). shmem_uncharge() was forgetting to unaccount __vm_enough_memory's charge, and shmem_charge() was forgetting it on the filesystem-full error path. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-24shmem: fix tmpfs to handle the huge= option properlyToshi Kani
shmem_get_unmapped_area() checks SHMEM_SB(sb)->huge incorrectly, which leads to a reversed effect of "huge=" mount option. Fix the check in shmem_get_unmapped_area(). Note, the default value of SHMEM_SB(sb)->huge remains as SHMEM_HUGE_NEVER. User will need to specify "huge=" option to enable huge page mappings. Reported-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-22fs: Give dentry to inode_change_ok() instead of inodeJan Kara
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-08-10thp: move shmem_huge_enabled() outside of SYSFS ifdefArnd Bergmann
The newly introduced shmem_huge_enabled() function has two definitions, but neither of them is visible if CONFIG_SYSFS is disabled, leading to a build error: mm/khugepaged.o: In function `khugepaged': khugepaged.c:(.text.khugepaged+0x3ca): undefined reference to `shmem_huge_enabled' This changes the #ifdef guards around the definition to match those that are used in the header file. Fixes: e496cf3d7821 ("thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE") Link: http://lkml.kernel.org/r/20160809123638.1357593-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03shmem: Fix link error if huge pages support is disabledGeert Uytterhoeven
If CONFIG_TRANSPARENT_HUGE_PAGECACHE=n, HPAGE_PMD_NR evaluates to BUILD_BUG_ON(), and may cause (e.g. with gcc 4.12): mm/built-in.o: In function `shmem_alloc_hugepage': shmem.c:(.text+0x17570): undefined reference to `__compiletime_assert_1365' To fix this, move the assignment to hindex after the check for huge pages support. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm: move most file-based accounting to the nodeMel Gorman
There are now a number of accounting oddities such as mapped file pages being accounted for on the node while the total number of file pages are accounted on the zone. This can be coped with to some extent but it's confusing so this patch moves the relevant file-based accounted. Due to throttling logic in the page allocator for reliable OOM detection, it is still necessary to track dirty and writeback pages on a per-zone basis. [mgorman@techsingularity.net: fix NR_ZONE_WRITE_PENDING accounting] Link: http://lkml.kernel.org/r/1468404004-5085-5-git-send-email-mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1467970510-21195-20-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem: split huge pages beyond i_size under memory pressureKirill A. Shutemov
Even if user asked to allocate huge pages always (huge=always), we should be able to free up some memory by splitting pages which are partly byound i_size if memory presure comes or once we hit limit on filesystem size (-o size=). In order to do this we maintain per-superblock list of inodes, which potentially have huge pages on the border of file size. Per-fs shrinker can reclaim memory by splitting such pages. If we hit -ENOSPC during shmem_getpage_gfp(), we try to split a page to free up space on the filesystem and retry allocation if it succeed. Link: http://lkml.kernel.org/r/1466021202-61880-37-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHEKirill A. Shutemov
For file mappings, we don't deposit page tables on THP allocation because it's not strictly required to implement split_huge_pmd(): we can just clear pmd and let following page faults to reconstruct the page table. But Power makes use of deposited page table to address MMU quirk. Let's hide THP page cache, including huge tmpfs, under separate config option, so it can be forbidden on Power. We can revert the patch later once solution for Power found. Link: http://lkml.kernel.org/r/1466021202-61880-36-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26khugepaged: add support of collapse for tmpfs/shmem pagesKirill A. Shutemov
This patch extends khugepaged to support collapse of tmpfs/shmem pages. We share fair amount of infrastructure with anon-THP collapse. Few design points: - First we are looking for VMA which can be suitable for mapping huge page; - If the VMA maps shmem file, the rest scan/collapse operations operates on page cache, not on page tables as in anon VMA case. - khugepaged_scan_shmem() finds a range which is suitable for huge page. The scan is lockless and shouldn't disturb system too much. - once the candidate for collapse is found, collapse_shmem() attempts to create a huge page: + scan over radix tree, making the range point to new huge page; + new huge page is not-uptodate, locked and freezed (refcount is 0), so nobody can touch them until we say so. + we swap in pages during the scan. khugepaged_scan_shmem() filters out ranges with more than khugepaged_max_ptes_swap swapped out pages. It's HPAGE_PMD_NR/8 by default. + old pages are isolated, unmapped and put to local list in case to be restored back if collapse failed. - if collapse succeed, we retract pte page tables from VMAs where huge pages mapping is possible. The huge page will be mapped as PMD on next minor fault into the range. Link: http://lkml.kernel.org/r/1466021202-61880-35-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem: make shmem_inode_info::lock irq-safeKirill A. Shutemov
We are going to need to call shmem_charge() under tree_lock to get accoutning right on collapse of small tmpfs pages into a huge one. The problem is that tree_lock is irq-safe and lockdep is not happy, that we take irq-unsafe lock under irq-safe[1]. Let's convert the lock to irq-safe. [1] https://gist.github.com/kiryl/80c0149e03ed35dfaf26628b8e03cdbc Link: http://lkml.kernel.org/r/1466021202-61880-34-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappingsKirill A. Shutemov
Let's wire up existing madvise() hugepage hints for file mappings. MADV_HUGEPAGE advise shmem to allocate huge page on page fault in the VMA. It only has effect if the filesystem is mounted with huge=advise or huge=within_size. MADV_NOHUGEPAGE prevents hugepage from being allocated on page fault in the VMA. It doesn't prevent a huge page from being allocated by other means, i.e. page fault into different mapping or write(2) into file. Link: http://lkml.kernel.org/r/1466021202-61880-31-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem: add huge pages supportKirill A. Shutemov
Here's basic implementation of huge pages support for shmem/tmpfs. It's all pretty streight-forward: - shmem_getpage() allcoates huge page if it can and try to inserd into radix tree with shmem_add_to_page_cache(); - shmem_add_to_page_cache() puts the page onto radix-tree if there's space for it; - shmem_undo_range() removes huge pages, if it fully within range. Partial truncate of huge pages zero out this part of THP. This have visible effect on fallocate(FALLOC_FL_PUNCH_HOLE) behaviour. As we don't really create hole in this case, lseek(SEEK_HOLE) may have inconsistent results depending what pages happened to be allocated. - no need to change shmem_fault: core-mm will map an compound page as huge if VMA is suitable; Link: http://lkml.kernel.org/r/1466021202-61880-30-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem: get_unmapped_area align huge pageHugh Dickins
Provide a shmem_get_unmapped_area method in file_operations, called at mmap time to decide the mapping address. It could be conditional on CONFIG_TRANSPARENT_HUGEPAGE, but save #ifdefs in other places by making it unconditional. shmem_get_unmapped_area() first calls the usual mm->get_unmapped_area (which we treat as a black box, highly dependent on architecture and config and executable layout). Lots of conditions, and in most cases it just goes with the address that chose; but when our huge stars are rightly aligned, yet that did not provide a suitable address, go back to ask for a larger arena, within which to align the mapping suitably. There have to be some direct calls to shmem_get_unmapped_area(), not via the file_operations: because of the way shmem_zero_setup() is called to create a shmem object late in the mmap sequence, when MAP_SHARED is requested with MAP_ANONYMOUS or /dev/zero. Though this only matters when /proc/sys/vm/shmem_huge has been set. Link: http://lkml.kernel.org/r/1466021202-61880-29-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26shmem: prepare huge= mount option and sysfs knobKirill A. Shutemov
This patch adds new mount option "huge=". It can have following values: - "always": Attempt to allocate huge pages every time we need a new page; - "never": Do not allocate huge pages; - "within_size": Only allocate huge page if it will be fully within i_size. Also respect fadvise()/madvise() hints; - "advise: Only allocate huge pages if requested with fadvise()/madvise(); Default is "never" for now. "mount -o remount,huge= /mountpoint" works fine after mount: remounting huge=never will not attempt to break up huge pages at all, just stop more from being allocated. No new config option: put this under CONFIG_TRANSPARENT_HUGEPAGE, which is the appropriate option to protect those who don't want the new bloat, and with which we shall share some pmd code. Prohibit the option when !CONFIG_TRANSPARENT_HUGEPAGE, just as mpol is invalid without CONFIG_NUMA (was hidden in mpol_parse_str(): make it explicit). Allow enabling THP only if the machine has_transparent_hugepage(). But what about Shmem with no user-visible mount? SysV SHM, memfds, shared anonymous mmaps (of /dev/zero or MAP_ANONYMOUS), GPU drivers' DRM objects, Ashmem. Though unlikely to suit all usages, provide sysfs knob /sys/kernel/mm/transparent_hugepage/shmem_enabled to experiment with huge on those. And allow shmem_enabled two further values: - "deny": For use in emergencies, to force the huge option off from all mounts; - "force": Force the huge option on for all - very useful for testing; Based on patch by Hugh Dickins. Link: http://lkml.kernel.org/r/1466021202-61880-28-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-10tmpfs: fix regression hang in fallocate undoHugh Dickins
The well-spotted fallocate undo fix is good in most cases, but not when fallocate failed on the very first page. index 0 then passes lend -1 to shmem_undo_range(), and that has two bad effects: (a) that it will undo every fallocation throughout the file, unrestricted by the current range; but more importantly (b) it can cause the undo to hang, because lend -1 is treated as truncation, which makes it keep on retrying until every page has gone, but those already fully instantiated will never go away. Big thank you to xfstests generic/269 which demonstrates this. Fixes: b9b4bb26af01 ("tmpfs: don't undo fallocate past its last page") Cc: stable@vger.kernel.org Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24tmpfs: don't undo fallocate past its last pageAnthony Romano
When fallocate is interrupted it will undo a range that extends one byte past its range of allocated pages. This can corrupt an in-use page by zeroing out its first byte. Instead, undo using the inclusive byte range. Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure") Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@coreos.com Signed-off-by: Anthony Romano <anthony.romano@coreos.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Brandon Philips <brandon@ifup.co> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>