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2015-09-09hugetlbfs: add hugetlbfs_fallocate()Mike Kravetz1-1/+178
This is based on the shmem version, but it has diverged quite a bit. We have no swap to worry about, nor the new file sealing. Add synchronication via the fault mutex table to coordinate page faults, fallocate allocation and fallocate hole punch. What this allows us to do is move physical memory in and out of a hugetlbfs file without having it mapped. This also gives us the ability to support MADV_REMOVE since it is currently implemented using fallocate(). MADV_REMOVE lets madvise() remove pages from the middle of a hugetlbfs file, which wasn't possible before. hugetlbfs fallocate only operates on whole huge pages. Based on code by Dave Hansen. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09hugetlbfs: truncate_hugepages() takes a range of pagesMike Kravetz1-10/+88
Modify truncate_hugepages() to take a range of pages (start, end) instead of simply start. If an end value of LLONG_MAX is passed, the current "truncate" functionality is maintained. Existing callers are modified to pass LLONG_MAX as end of range. By keying off end == LLONG_MAX, the routine behaves differently for truncate and hole punch. Page removal is now synchronized with page allocation via faults by using the fault mutex table. The hole punch case can experience the rare region_del error and must handle accordingly. Add the routine hugetlb_fix_reserve_counts to fix up reserve counts in the case where region_del returns an error. Since the routine handles more than just the truncate case, it is renamed to remove_inode_hugepages(). To be consistent, the routine truncate_huge_page() is renamed remove_huge_page(). Downstream of remove_inode_hugepages(), the routine hugetlb_unreserve_pages() is also modified to take a range of pages. hugetlb_unreserve_pages is modified to detect an error from region_del and pass it back to the caller. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09hugetlbfs: hugetlb_vmtruncate_list() needs to take a range to deleteMike Kravetz1-7/+18
fallocate hole punch will want to unmap a specific range of pages. Modify the existing hugetlb_vmtruncate_list() routine to take a start/end range. If end is 0, this indicates all pages after start should be unmapped. This is the same as the existing truncate functionality. Modify existing callers to add 0 as end of range. Since the routine will be used in hole punch as well as truncate operations, it is more appropriately renamed to hugetlb_vmdelete_list(). Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09mm: /proc/pid/smaps:: show proportional swap share of the mappingMinchan Kim1-2/+16
We want to know per-process workingset size for smart memory management on userland and we use swap(ex, zram) heavily to maximize memory efficiency so workingset includes swap as well as RSS. On such system, if there are lots of shared anonymous pages, it's really hard to figure out exactly how many each process consumes memory(ie, rss + wap) if the system has lots of shared anonymous memory(e.g, android). This patch introduces SwapPss field on /proc/<pid>/smaps so we can get more exact workingset size per process. Bongkyu tested it. Result is below. 1. 50M used swap SwapTotal: 461976 kB SwapFree: 411192 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 48236 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 141184 2. 240M used swap SwapTotal: 461976 kB SwapFree: 216808 kB $ adb shell cat /proc/*/smaps | grep "SwapPss:" | awk '{sum += $2} END {print sum}'; 230315 $ adb shell cat /proc/*/smaps | grep "Swap:" | awk '{sum += $2} END {print sum}'; 1387744 [akpm@linux-foundation.org: simplify kunmap_atomic() call] Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Bongkyu Kim <bongkyu.kim@lge.com> Tested-by: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09pagemap: add mmap-exclusive bit for marking pages mapped only hereKonstantin Khlebnikov1-1/+13
This patch sets bit 56 in pagemap if this page is mapped only once. It allows to detect exclusively used pages without exposing PFN: present file exclusive state 0 0 0 non-present 1 1 0 file page mapped somewhere else 1 1 1 file page mapped only here 1 0 0 anon non-CoWed page (shared with parent/child) 1 0 1 anon CoWed page (or never forked) CoWed pages in (MAP_FILE | MAP_PRIVATE) areas are anon in this context. MMap-exclusive bit doesn't reflect potential page-sharing via swapcache: page could be mapped once but has several swap-ptes which point to it. Application could detect that by swap bit in pagemap entry and touch that pte via /proc/pid/mem to get real information. See http://lkml.kernel.org/r/CAEVpBa+_RyACkhODZrRvQLs80iy0sqpdrd0AaP_-tgnX3Y9yNQ@mail.gmail.com Requested by Mark Williamson. [akpm@linux-foundation.org: fix spello] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09pagemap: hide physical addresses from non-privileged usersKonstantin Khlebnikov1-11/+14
This patch makes pagemap readable for normal users and hides physical addresses from them. For some use-cases PFN isn't required at all. See http://lkml.kernel.org/r/1425935472-17949-1-git-send-email-kirill@shutemov.name Fixes: ab676b7d6fbf ("pagemap: do not leak physical addresses to non-privileged userspace") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09pagemap: rework hugetlb and thp reportKonstantin Khlebnikov1-56/+44
This patch moves pmd dissection out of reporting loop: huge pages are reported as bunch of normal pages with contiguous PFNs. Add missing "FILE" bit in hugetlb vmas. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09pagemap: switch to the new format and do some cleanupKonstantin Khlebnikov1-97/+53
This patch removes page-shift bits (scheduled to remove since 3.11) and completes migration to the new bit layout. Also it cleans messy macro. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09pagemap: check permissions and capabilities at open timeKonstantin Khlebnikov1-20/+28
This patchset makes pagemap useable again in the safe way (after row hammer bug it was made CAP_SYS_ADMIN-only). This patchset restores access for non-privileged users but hides PFNs from them. Also it adds bit 'map-exclusive' which is set if page is mapped only here: it helps in estimation of working set without exposing pfns and allows to distinguish CoWed and non-CoWed private anonymous pages. Second patch removes page-shift bits and completes migration to the new pagemap format: flags soft-dirty and mmap-exclusive are available only in the new format. This patch (of 5): This patch moves permission checks from pagemap_read() into pagemap_open(). Pointer to mm is saved in file->private_data. This reference pins only mm_struct itself. /proc/*/mem, maps, smaps already work in the same way. See http://lkml.kernel.org/r/CA+55aFyKpWrt_Ajzh1rzp_GcwZ4=6Y=kOv8hBz172CFJp6L8Tg@mail.gmail.com Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09mm: take i_mmap_lock in unmap_mapping_range() for DAXKirill A. Shutemov1-16/+19
DAX is not so special: we need i_mmap_lock to protect mapping->i_mmap. __dax_pmd_fault() uses unmap_mapping_range() shoot out zero page from all mappings. We need to drop i_mmap_lock there to avoid lock deadlock. Re-aquiring the lock should be fine since we check i_size after the point. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: use linear_page_index()Matthew Wilcox1-1/+1
I was basically open-coding it (thanks to copying code from do_fault() which probably also needs to be fixed). Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: ensure that zero pages are removed from other processesMatthew Wilcox1-1/+5
If the first access to a huge page was a store, there would be no existing zero pmd in this process's page tables. There could be a zero pmd in another process's page tables, if it had done a load. We can detect this case by noticing that the buffer_head returned from the filesystem is New, and ensure that other processes mapping this huge page have their page tables flushed. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reported-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>
2015-09-09dax: don't use set_huge_zero_page()Kirill A. Shutemov1-6/+12
This is another place where DAX assumed that pgtable_t was a pointer. Open code the important parts of set_huge_zero_page() in DAX and make set_huge_zero_page() static again. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: fix race between simultaneous faultsMatthew Wilcox1-16/+17
If two threads write-fault on the same hole at the same time, the winner of the race will return to userspace and complete their store, only to have the loser overwrite their store with zeroes. Fix this for now by taking the i_mmap_sem for write instead of read, and do so outside the call to get_block(). Now the loser of the race will see the block has already been zeroed, and will not zero it again. This severely limits our scalability. I have ideas for improving it, but those can wait for a later patch. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09ext4: start transaction before calling into DAXMatthew Wilcox1-3/+52
Jan Kara pointed out that in the case where we are writing to a hole, we can end up with a lock inversion between the page lock and the journal lock. We can avoid this by starting the transaction in ext4 before calling into DAX. The journal lock nests inside the superblock pagefault lock, so we have to duplicate that code from dax_fault, like XFS does. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09ext4: add ext4_get_block_dax()Matthew Wilcox3-3/+16
DAX wants different semantics from any currently-existing ext4 get_block callback. Unlike ext4_get_block_write(), it needs to honour the 'create' flag, and unlike ext4_get_block(), it needs to be able to return unwritten extents. So introduce a new ext4_get_block_dax() which has those semantics. We could also change ext4_get_block_write() to honour the 'create' flag, but that might have consequences on other users that I do not currently understand. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: improve comment about truncate raceMatthew Wilcox1-1/+6
Jan Kara pointed out I should be more explicit here about the perils of racing against truncate. The comment is mostly the same as for the PTE case. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09ext4: use ext4_get_block_write() for DAXMatthew Wilcox1-4/+4
DAX relies on the get_block function either zeroing newly allocated blocks before they're findable by subsequent calls to get_block, or marking newly allocated blocks as unwritten. ext4_get_block() cannot create unwritten extents, but ext4_get_block_write() can. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reported-by: Andy Rudoff <andy.rudoff@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09fs/dax.c: fix typo in #endif commentValentin Rothberg1-1/+1
Fix typo s/CONFIG_TRANSPARENT_HUGEPAGES/CONFIG_TRANSPARENT_HUGEPAGE/ in #endif comment introduced by commit 2b26a9206d6a ("dax: add huge page fault support"). Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09xfs: huge page fault supportMatthew Wilcox2-1/+30
Use DAX to provide support for huge pages. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09ext4: huge page fault supportMatthew Wilcox1-1/+9
Use DAX to provide support for huge pages. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09ext2: huge page fault supportMatthew Wilcox1-1/+8
Use DAX to provide support for huge pages. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: add huge page fault supportMatthew Wilcox1-0/+152
This is the support code for DAX-enabled filesystems to allow them to provide huge pages in response to faults. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-09dax: move DAX-related functions to a new headerMatthew Wilcox7-0/+7
In order to handle the !CONFIG_TRANSPARENT_HUGEPAGES case, we need to return VM_FAULT_FALLBACK from the inlined dax_pmd_fault(), which is defined in linux/mm.h. Given that we don't want to include <linux/mm.h> in <linux/fs.h>, the easiest solution is to move the DAX-related functions to a new header, <linux/dax.h>. We could also have moved VM_FAULT_* definitions to a new header, or a different header that isn't quite such a boil-the-ocean header as <linux/mm.h>, but this felt like the best option. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08Merge tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds34-645/+967
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable patches: - Fix atomicity of pNFS commit list updates - Fix NFSv4 handling of open(O_CREAT|O_EXCL|O_RDONLY) - nfs_set_pgio_error sometimes misses errors - Fix a thinko in xs_connect() - Fix borkage in _same_data_server_addrs_locked() - Fix a NULL pointer dereference of migration recovery ops for v4.2 client - Don't let the ctime override attribute barriers. - Revert "NFSv4: Remove incorrect check in can_open_delegated()" - Ensure flexfiles pNFS driver updates the inode after write finishes - flexfiles must not pollute the attribute cache with attrbutes from the DS - Fix a protocol error in layoutreturn - Fix a protocol issue with NFSv4.1 CLOSE stateids Bugfixes + cleanups - pNFS blocks bugfixes from Christoph - Various cleanups from Anna - More fixes for delegation corner cases - Don't fsync twice for O_SYNC/IS_SYNC files - Fix pNFS and flexfiles layoutstats bugs - pnfs/flexfiles: avoid duplicate tracking of mirror data - pnfs: Fix layoutget/layoutreturn/return-on-close serialisation issues - pnfs/flexfiles: error handling retries a layoutget before fallback to MDS Features: - Full support for the OPEN NFS4_CREATE_EXCLUSIVE4_1 mode from Kinglong - More RDMA client transport improvements from Chuck - Removal of the deprecated ib_reg_phys_mr() and ib_rereg_phys_mr() verbs from the SUNRPC, Lustre and core infiniband tree. - Optimise away the close-to-open getattr if there is no cached data" * tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (108 commits) NFSv4: Respect the server imposed limit on how many changes we may cache NFSv4: Express delegation limit in units of pages Revert "NFS: Make close(2) asynchronous when closing NFS O_DIRECT files" NFS: Optimise away the close-to-open getattr if there is no cached data NFSv4.1/flexfiles: Clean up ff_layout_write_done_cb/ff_layout_commit_done_cb NFSv4.1/flexfiles: Mark the layout for return in ff_layout_io_track_ds_error() nfs: Remove unneeded checking of the return value from scnprintf nfs: Fix truncated client owner id without proto type NFSv4.1/flexfiles: Mark layout for return if the mirrors are invalid NFSv4.1/flexfiles: RW layouts are valid only if all mirrors are valid NFSv4.1/flexfiles: Fix incorrect usage of pnfs_generic_mark_devid_invalid() NFSv4.1/flexfiles: Fix freeing of mirrors NFSv4.1/pNFS: Don't request a minimal read layout beyond the end of file NFSv4.1/pnfs: Handle LAYOUTGET return values correctly NFSv4.1/pnfs: Don't ask for a read layout for an empty file. NFSv4.1: Fix a protocol issue with CLOSE stateids NFSv4.1/flexfiles: Don't mark the entire deviceid as bad for file errors SUNRPC: Prevent SYN+SYNACK+RST storms SUNRPC: xs_reset_transport must mark the connection as disconnected NFSv4.1/pnfs: Ensure layoutreturn reserves space for the opaque payload ...
2015-09-07Merge tag 'xfs-for-linus-4.3' of ↵Linus Torvalds55-478/+861
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "There isn't a whole lot to this update - it's mostly bug fixes and they are spread pretty much all over XFS. There are some corruption fixes, some fixes for log recovery, some fixes that prevent unount from hanging, a lockdep annotation rework for inode locking to prevent false positives and the usual random bunch of cleanups and minor improvements. Deatils: - large rework of EFI/EFD lifecycle handling to fix log recovery corruption issues, crashes and unmount hangs - separate metadata UUID on disk to enable changing boot label UUID for v5 filesystems - fixes for gcc miscompilation on certain platforms and optimisation levels - remote attribute allocation and recovery corruption fixes - inode lockdep annotation rework to fix bugs with too many subclasses - directory inode locking changes to prevent lockdep false positives - a handful of minor corruption fixes - various other small cleanups and bug fixes" * tag 'xfs-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (42 commits) xfs: fix error gotos in xfs_setattr_nonsize xfs: add mssing inode cache attempts counter increment xfs: return errors from partial I/O failures to files libxfs: bad magic number should set da block buffer error xfs: fix non-debug build warnings xfs: collapse allocsize and biosize mount option handling xfs: Fix file type directory corruption for btree directories xfs: lockdep annotations throw warnings on non-debug builds xfs: Fix uninitialized return value in xfs_alloc_fix_freelist() xfs: inode lockdep annotations broke non-lockdep build xfs: flush entire file on dio read/write to cached file xfs: Fix xfs_attr_leafblock definition libxfs: readahead of dir3 data blocks should use the read verifier xfs: stop holding ILOCK over filldir callbacks xfs: clean up inode lockdep annotations xfs: swap leaf buffer into path struct atomically during path shift xfs: relocate sparse inode mount warning xfs: dquots should be stamped with sb_meta_uuid xfs: log recovery needs to validate against sb_meta_uuid xfs: growfs not aware of sb_meta_uuid ...
2015-09-07NFSv4: Respect the server imposed limit on how many changes we may cacheTrond Myklebust5-11/+55
The NFSv4 delegation spec allows the server to tell a client to limit how much data it cache after the file is closed. In return, the server guarantees enough free space to avoid ENOSPC situations, etc. Prior to this patch, we assumed we could always cache aggressively after close. Unfortunately, this causes problems with servers that set the limit to 0 and therefore do not offer any ENOSPC guarantees. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-07NFSv4: Express delegation limit in units of pagesTrond Myklebust3-9/+13
Since we're tracking modifications to the page cache on a per-page basis, it makes sense to express the limit to how much we may cache in units of pages. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-06Merge branch 'for-linus' of ↵Linus Torvalds18-1074/+865
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "In this one: - d_move fixes (Eric Biederman) - UFS fixes (me; locking is mostly sane now, a bunch of bugs in error handling ought to be fixed) - switch of sb_writers to percpu rwsem (Oleg Nesterov) - superblock scalability (Josef Bacik and Dave Chinner) - swapon(2) race fix (Hugh Dickins)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits) vfs: Test for and handle paths that are unreachable from their mnt_root dcache: Reduce the scope of i_lock in d_splice_alias dcache: Handle escaped paths in prepend_path mm: fix potential data race in SyS_swapon inode: don't softlockup when evicting inodes inode: rename i_wb_list to i_io_list sync: serialise per-superblock sync operations inode: convert inode_sb_list_lock to per-sb inode: add hlist_fake to avoid the inode hash lock in evict writeback: plug writeback at a high level change sb_writers to use percpu_rw_semaphore shift percpu_counter_destroy() into destroy_super_work() percpu-rwsem: kill CONFIG_PERCPU_RWSEM percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire() percpu-rwsem: introduce percpu_down_read_trylock() document rwsem_release() in sb_wait_write() fix the broken lockdep logic in __sb_start_write() introduce __sb_writers_{acquired,release}() helpers ufs_inode_get{frag,block}(): get rid of 'phys' argument ufs_getfrag_block(): tidy up a bit ...
2015-09-06Merge tag 'for-linus-4.3-merge-window-part-1' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs Pull 9p updates from Eric Van Hensbergen: "Just a few cleanups for 4.3 merge window for the 9p file system. I've gotten several more over the past week, but this group has been in for-next for at least a couple of weeks so I figured I'd push them first while I test the rest. Most of the ones not in this set are bug-fixes anyways so I could hold them for rc1" * tag 'for-linus-4.3-merge-window-part-1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: 9p: fix return code of read() when count is 0 9p: remove unused option Opt_trans
2015-09-06Merge tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linuxLinus Torvalds21-299/+382
Pull nfsd updates from Bruce Fields: "Nothing major, but: - Add Jeff Layton as an nfsd co-maintainer: no change to existing practice, just an acknowledgement of the status quo. - Two patches ("nfsd: ensure that...") for a race overlooked by the state locking rewrite, causing a crash noticed by multiple users. - Lots of smaller bugfixes all over from Kinglong Mee. - From Jeff, some cleanup of server rpc code in preparation for possible shift of nfsd threads to workqueues" * tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linux: (52 commits) nfsd: deal with DELEGRETURN racing with CB_RECALL nfsd: return CLID_INUSE for unexpected SETCLIENTID_CONFIRM case nfsd: ensure that delegation stateid hash references are only put once nfsd: ensure that the ol stateid hash reference is only put once net: sunrpc: fix tracepoint Warning: unknown op '->' nfsd: allow more than one laundry job to run at a time nfsd: don't WARN/backtrace for invalid container deployment. fs: fix fs/locks.c kernel-doc warning nfsd: Add Jeff Layton as co-maintainer NFSD: Return word2 bitmask if setting security label in OPEN/CREATE NFSD: Set the attributes used to store the verifier for EXCLUSIVE4_1 nfsd: SUPPATTR_EXCLCREAT must be encoded before SECURITY_LABEL. nfsd: Fix an FS_LAYOUT_TYPES/LAYOUT_TYPES encode bug NFSD: Store parent's stat in a separate value nfsd: Fix two typos in comments lockd: NLM grace period shouldn't block NFSv4 opens nfsd: include linux/nfs4.h in export.h sunrpc: Switch to using hash list instead single list sunrpc/nfsd: Remove redundant code by exports seq_operations functions sunrpc: Store cache_detail in seq_file's private directly ...
2015-09-06Merge branch 'for-linus-4.3' of ↵Linus Torvalds21-338/+1134
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This has Jeff Mahoney's long standing trim patch that fixes corners where trims were missing. Omar has some raid5/6 fixes, especially for using scrub and device replace when devices are missing. Zhao Lie continues cleaning and fixing things, this series fixes some really hard to hit corners in xfstests. I had to pull it last merge window due to some deadlocks, but those are now resolved. I added support for Tejun's new blkio controllers. It seems to work well for single devices, we'll expand to multi-device as well" * 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (47 commits) btrfs: fix compile when block cgroups are not enabled Btrfs: fix file read corruption after extent cloning and fsync Btrfs: check if previous transaction aborted to avoid fs corruption btrfs: use __GFP_NOFAIL in alloc_btrfs_bio btrfs: Prevent from early transaction abort btrfs: Remove unused arguments in tree-log.c btrfs: Remove useless condition in start_log_trans() Btrfs: add support for blkio controllers Btrfs: remove unused mutex from struct 'btrfs_fs_info' Btrfs: fix parity scrub of RAID 5/6 with missing device Btrfs: fix device replace of a missing RAID 5/6 device Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation Btrfs: count devices correctly in readahead during RAID 5/6 replace Btrfs: remove misleading handling of missing device scrub btrfs: fix clone / extent-same deadlocks Btrfs: fix defrag to merge tail file extent Btrfs: fix warning in backref walking btrfs: Add WARN_ON() for double lock in btrfs_tree_lock() btrfs: Remove root argument in extent_data_ref_count() btrfs: Fix wrong comment of btrfs_alloc_tree_block() ...
2015-09-05mm: move ->mremap() from file_operations to vm_operations_structOleg Nesterov1-9/+18
vma->vm_ops->mremap() looks more natural and clean in move_vma(), and this way ->mremap() can have more users. Say, vdso. While at it, s/aio_ring_remap/aio_ring_mremap/. Note: this is the minimal change before ->mremap() finds another user in file_operations; this method should have more arguments, and it can be used to kill arch_remap(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Hugh Dickins <hughd@google.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: avoid missing wakeups during refile in userfaultfd_readAndrea Arcangeli1-2/+24
During the refile in userfaultfd_read both waitqueues could look empty to the lockless wake_userfault(). Use a seqcount to prevent this false negative that could leave an userfault blocked. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: allow signals to interrupt a userfaultAndrea Arcangeli1-3/+32
This is only simple to achieve if the userfault is going to return to userland (not to the kernel) because we can avoid returning VM_FAULT_RETRY despite we temporarily released the mmap_sem. The fault would just be retried by userland then. This is safe at least on x86 and powerpc (the two archs with the syscall implemented so far). Hint to verify for which archs this is safe: after handle_mm_fault returns, no access to data structures protected by the mmap_sem must be done by the fault code in arch/*/mm/fault.c until up_read(&mm->mmap_sem) is called. This has two main benefits: signals can run with lower latency in production (signals aren't blocked by userfaults and userfaults are immediately repeated after signal processing) and gdb can then trivially debug the threads blocked in this kind of userfaults coming directly from userland. On a side note: while gdb has a need to get signal processed, coredumps always worked perfectly with userfaults, no matter if the userfault is triggered by GUP a kernel copy_user or directly from userland. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: require UFFDIO_API before other ioctlsAndrea Arcangeli1-1/+3
UFFDIO_API was already forced before read/poll could work. This makes the code more strict to force it also for all other ioctls. All users would already have been required to call UFFDIO_API before invoking other ioctls but this makes it more explicit. This will ensure we can change all ioctls (all but UFFDIO_API/struct uffdio_api) with a bump of uffdio_api.api. There's no actual plan or need to change the API or the ioctl, the current API already should cover fine even the non cooperative usage, but this is just for the longer term future just in case. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: UFFDIO_COPY and UFFDIO_ZEROPAGEAndrea Arcangeli1-0/+96
These two ioctl allows to either atomically copy or to map zeropages into the virtual address space. This is used by the thread that opened the userfaultfd to resolve the userfaults. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: buildsystem activationAndrea Arcangeli1-0/+1
This allows to select the userfaultfd during configuration to build it. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: solve the race between UFFDIO_COPY|ZEROPAGE and readAndrea Arcangeli1-15/+66
Solve in-kernel the race between UFFDIO_COPY|ZEROPAGE and userfaultfd_read if they are run on different threads simultaneously. Until now qemu solved the race in userland: the race was explicitly and intentionally left for userland to solve. However we can also solve it in kernel. Requiring all users to solve this race if they use two threads (one for the background transfer and one for the userfault reads) isn't very attractive from an API prospective, furthermore this allows to remove a whole bunch of mutex and bitmap code from qemu, making it faster. The cost of __get_user_pages_fast should be insignificant considering it scales perfectly and the pagetables are already hot in the CPU cache, compared to the overhead in userland to maintain those structures. Applying this patch is backwards compatible with respect to the userfaultfd userland API, however reverting this change wouldn't be backwards compatible anymore. Without this patch qemu in the background transfer thread, has to read the old state, and do UFFDIO_WAKE if old_state is missing but it become REQUESTED by the time it tries to set it to RECEIVED (signaling the other side received an userfault). vcpu background_thr userfault_thr ----- ----- ----- vcpu0 handle_mm_fault() postcopy_place_page read old_state -> MISSING UFFDIO_COPY 0x7fb76a139000 (no wakeup, still pending) vcpu0 fault at 0x7fb76a139000 enters handle_userfault poll() is kicked poll() -> POLLIN read() -> 0x7fb76a139000 postcopy_pmi_change_state(MISSING, REQUESTED) -> REQUESTED tmp_state = postcopy_pmi_change_state(old_state, RECEIVED) -> REQUESTED /* check that no userfault raced with UFFDIO_COPY */ if (old_state == MISSING && tmp_state == REQUESTED) UFFDIO_WAKE from background thread And a second case where a UFFDIO_WAKE would be needed is in the userfault thread: vcpu background_thr userfault_thr ----- ----- ----- vcpu0 handle_mm_fault() postcopy_place_page read old_state -> MISSING UFFDIO_COPY 0x7fb76a139000 (no wakeup, still pending) tmp_state = postcopy_pmi_change_state(old_state, RECEIVED) -> RECEIVED vcpu0 fault at 0x7fb76a139000 enters handle_userfault poll() is kicked poll() -> POLLIN read() -> 0x7fb76a139000 if (postcopy_pmi_change_state(MISSING, REQUESTED) == RECEIVED) UFFDIO_WAKE from userfault thread This patch removes the need of both UFFDIO_WAKE and of the associated per-page tristate as well. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: allocate the userfaultfd_ctx cacheline alignedAndrea Arcangeli1-8/+31
Use proper slab to guarantee alignment. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: optimize read() and poll() to be O(1)Andrea Arcangeli1-74/+111
This makes read O(1) and poll that was already O(1) becomes lockless. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: wake pending userfaultsAndrea Arcangeli1-22/+43
This is an optimization but it's a userland visible one and it affects the API. The downside of this optimization is that if you call poll() and you get POLLIN, read(ufd) may still return -EAGAIN. The blocked userfault may be waken by a different thread, before read(ufd) comes around. This in short means that poll() isn't really usable if the userfaultfd is opened in blocking mode. userfaults won't wait in "pending" state to be read anymore and any UFFDIO_WAKE or similar operations that has the objective of waking userfaults after their resolution, will wake all blocked userfaults for the resolved range, including those that haven't been read() by userland yet. The behavior of poll() becomes not standard, but this obviates the need of "spurious" UFFDIO_WAKE and it lets the userland threads to restart immediately without requiring an UFFDIO_WAKE. This is even more significant in case of repeated faults on the same address from multiple threads. This optimization is justified by the measurement that the number of spurious UFFDIO_WAKE accounts for 5% and 10% of the total userfaults for heavy workloads, so it's worth optimizing those away. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: change the read API to return a uffd_msgAndrea Arcangeli1-33/+46
I had requests to return the full address (not the page aligned one) to userland. It's not entirely clear how the page offset could be relevant because userfaults aren't like SIGBUS that can sigjump to a different place and it actually skip resolving the fault depending on a page offset. There's currently no real way to skip the fault especially because after a UFFDIO_COPY|ZEROPAGE, the fault is optimized to be retried within the kernel without having to return to userland first (not even self modifying code replacing the .text that touched the faulting address would prevent the fault to be repeated). Userland cannot skip repeating the fault even more so if the fault was triggered by a KVM secondary page fault or any get_user_pages or any copy-user inside some syscall which will return to kernel code. The second time FAULT_FLAG_RETRY_NOWAIT won't be set leading to a SIGBUS being raised because the userfault can't wait if it cannot release the mmap_map first (and FAULT_FLAG_RETRY_NOWAIT is required for that). Still returning userland a proper structure during the read() on the uffd, can allow to use the current UFFD_API for the future non-cooperative extensions too and it looks cleaner as well. Once we get additional fields there's no point to return the fault address page aligned anymore to reuse the bits below PAGE_SHIFT. The only downside is that the read() syscall will read 32bytes instead of 8bytes but that's not going to be measurable overhead. The total number of new events that can be extended or of new future bits for already shipped events, is limited to 64 by the features field of the uffdio_api structure. If more will be needed a bump of UFFD_API will be required. [akpm@linux-foundation.org: use __packed] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: Rename uffd_api.bits into .featuresPavel Emelyanov1-2/+2
This is (seems to be) the minimal thing that is required to unblock standard uffd usage from the non-cooperative one. Now more bits can be added to the features field indicating e.g. UFFD_FEATURE_FORK and others needed for the latter use-case. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: add new syscall to provide memory externalizationAndrea Arcangeli1-0/+1036
Once an userfaultfd has been created and certain region of the process virtual address space have been registered into it, the thread responsible for doing the memory externalization can manage the page faults in userland by talking to the kernel using the userfaultfd protocol. poll() can be used to know when there are new pending userfaults to be read (POLLIN). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05userfaultfd: add VM_UFFD_MISSING and VM_UFFD_WPAndrea Arcangeli1-0/+2
These two flags gets set in vma->vm_flags to tell the VM common code if the userfaultfd is armed and in which mode (only tracking missing faults, only tracking wrprotect faults or both). If neither flags is set it means the userfaultfd is not armed on the vma. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05fs: create and use seq_show_option for escapingKees Cook11-24/+26
Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Jan Kara <jack@suse.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05ocfs2: clean up redundant NULL checks before kfreeJoseph Qi2-5/+3
NULL check before kfree is redundant and so clean them up. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05ocfs2: neaten do_error, ocfs2_error and ocfs2_abortJoe Perches14-202/+163
These uses sometimes do and sometimes don't have '\n' terminations. Make the uses consistently use '\n' terminations and remove the newline from the functions. Miscellanea: o Coalesce formats o Realign arguments Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-05ocfs2: do not set fs read-only if rec[0] is empty while committing truncateXue jiufei1-6/+38
While appending an extent to a file, it will call these functions: ocfs2_insert_extent -> call ocfs2_grow_tree() if there's no free rec -> ocfs2_add_branch add a new branch to extent tree, now rec[0] in the leaf of rightmost path is empty -> ocfs2_do_insert_extent -> ocfs2_rotate_tree_right -> ocfs2_extend_rotate_transaction -> jbd2_journal_restart if jbd2_journal_extend fail -> ocfs2_insert_path -> ocfs2_extend_trans -> jbd2_journal_restart if jbd2_journal_extend fail -> ocfs2_insert_at_leaf -> ocfs2_et_update_clusters Function jbd2_journal_restart() may be called and it may happened that buffers dirtied in ocfs2_add_branch() are committed while buffers dirtied in ocfs2_insert_at_leaf() and ocfs2_et_update_clusters() are not. So an empty rec[0] is left in rightmost path which will cause read-only filesystem when call ocfs2_commit_truncate() with the error message: "Inode %lu has an empty extent record". This is not a serious problem, so remove the rightmost path when call ocfs2_commit_truncate(). Signed-off-by: joyce.xue <xuejiufei@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>