linux/fs, branch v4.20

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-12-23T18:40:41Z

Pull vfs fixes from Al Viro: "A couple of fixes - no common topic ;-)" [ The aio spectre patch also came in from Jens, so now we have that doubly fixed .. ] * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: proc/sysctl: don't return ENOMEM on lookup when a table is unregistering aio: fix spectre gadget in lookup_ioctx

Revert "vfs: Allow userns root to call mknod on owned filesystems."

2018-12-22T22:18:34Z

This reverts commit 55956b59df336f6738da916dbb520b6e37df9fbd. commit 55956b59df33 ("vfs: Allow userns root to call mknod on owned filesystems.") enabled mknod() in user namespaces for userns root if CAP_MKNOD is available. However, these device nodes are useless since any filesystem mounted from a non-initial user namespace will set the SB_I_NODEV flag on the filesystem. Now, when a device node s created in a non-initial user namespace a call to open() on said device node will fail due to: bool may_open_dev(const struct path *path) { return !(path->mnt->mnt_flags & MNT_NODEV) && !(path->mnt->mnt_sb->s_iflags & SB_I_NODEV); } The problem with this is that as of the aforementioned commit mknod() creates partially functional device nodes in non-initial user namespaces. In particular, it has the consequence that as of the aforementioned commit open() will be more privileged with respect to device nodes than mknod(). Before it was the other way around. Specifically, if mknod() succeeded then it was transparent for any userspace application that a fatal error must have occured when open() failed. All of this breaks multiple userspace workloads and a widespread assumption about how to handle mknod(). Basically, all container runtimes and systemd live by the slogan "ask for forgiveness not permission" when running user namespace workloads. For mknod() the assumption is that if the syscall succeeds the device nodes are useable irrespective of whether it succeeds in a non-initial user namespace or not. This logic was chosen explicitly to allow for the glorious day when mknod() will actually be able to create fully functional device nodes in user namespaces. A specific problem people are already running into when running 4.18 rc kernels are failing systemd services. For any distro that is run in a container systemd services started with the PrivateDevices= property set will fail to start since the device nodes in question cannot be opened (cf. the arguments in [1]). Full disclosure, Seth made the very sound argument that it is already possible to end up with partially functional device nodes. Any filesystem mounted with MS_NODEV set will allow mknod() to succeed but will not allow open() to succeed. The difference to the case here is that the MS_NODEV case is transparent to userspace since it is an explicitly set mount option while the SB_I_NODEV case is an implicit property enforced by the kernel and hence opaque to userspace. [1]: https://github.com/systemd/systemd/pull/9483 Signed-off-by: Christian Brauner Cc: "Eric W. Biederman" Cc: Seth Forshee Cc: Serge Hallyn Signed-off-by: Linus Torvalds

Merge tag '4.20-rc7-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

2018-12-21T16:56:31Z

Pull smb3 fix from Steve French: "An important smb3 fix for an regression to some servers introduced by compounding optimization to rmdir. This fix has been tested by multiple developers (including me) with the usual private xfstesting, but also by the new cifs/smb3 "buildbot" xfstest VMs (thank you Ronnie and Aurelien for good work on this automation). The automated testing has been updated so that it will catch problems like this in the future. Note that Pavel discovered (very recently) some unrelated but extremely important bugs in credit handling (smb3 flow control problem that can lead to disconnects/reconnects) when compounding, that I would have liked to send in ASAP but the complete testing of those two fixes may not be done in time and have to wait for 4.21" * tag '4.20-rc7-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: smb3: Fix rmdir compounding regression to strict servers

Merge tag 'upstream-4.20-rc7' of git://git.infradead.org/linux-ubifs

2018-12-20T22:17:24Z

Pull UBI/UBIFS fixes from Richard Weinberger: - Kconfig dependency fixes for our new auth feature - Fix for selecting the right compressor when creating a fs - Bugfix for a bug in UBIFS's O_TMPFILE implementation - Refcounting fixes for UBI * tag 'upstream-4.20-rc7' of git://git.infradead.org/linux-ubifs: ubifs: Handle re-linking of inodes correctly while recovery ubi: Do not drop UBI device reference before using ubi: Put MTD device after it is not used ubifs: Fix default compression selection in ubifs ubifs: Fix memory leak on error condition ubifs: auth: Add CONFIG_KEYS dependency ubifs: CONFIG_UBIFS_FS_AUTHENTICATION should depend on UBIFS_FS ubifs: replay: Fix high stack usage

iomap: Revert "fs/iomap.c: get/put the page in iomap_page_create/release()"

2018-12-20T15:22:51Z

This reverts commit 61c6de667263184125d5ca75e894fcad632b0dd3. The reverted commit added page reference counting to iomap page structures that are used to track block size < page size state. This was supposed to align the code with page migration page accounting assumptions, but what it has done instead is break XFS filesystems. Every fstests run I've done on sub-page block size XFS filesystems has since picking up this commit 2 days ago has failed with bad page state errors such as: # ./run_check.sh "-m rmapbt=1,reflink=1 -i sparse=1 -b size=1k" "generic/038" .... SECTION -- xfs FSTYP -- xfs (debug) PLATFORM -- Linux/x86_64 test1 4.20.0-rc6-dgc+ MKFS_OPTIONS -- -f -m rmapbt=1,reflink=1 -i sparse=1 -b size=1k /dev/sdc MOUNT_OPTIONS -- /dev/sdc /mnt/scratch generic/038 454s ... run fstests generic/038 at 2018-12-20 18:43:05 XFS (sdc): Unmounting Filesystem XFS (sdc): Mounting V5 Filesystem XFS (sdc): Ending clean mount BUG: Bad page state in process kswapd0 pfn:3a7fa page:ffffea0000ccbeb0 count:0 mapcount:0 mapping:ffff88800d9b6360 index:0x1 flags: 0xfffffc0000000() raw: 000fffffc0000000 dead000000000100 dead000000000200 ffff88800d9b6360 raw: 0000000000000001 0000000000000000 00000000ffffffff page dumped because: non-NULL mapping CPU: 0 PID: 676 Comm: kswapd0 Not tainted 4.20.0-rc6-dgc+ #915 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 Call Trace: dump_stack+0x67/0x90 bad_page.cold.116+0x8a/0xbd free_pcppages_bulk+0x4bf/0x6a0 free_unref_page_list+0x10f/0x1f0 shrink_page_list+0x49d/0xf50 shrink_inactive_list+0x19d/0x3b0 shrink_node_memcg.constprop.77+0x398/0x690 ? shrink_slab.constprop.81+0x278/0x3f0 shrink_node+0x7a/0x2f0 kswapd+0x34b/0x6d0 ? node_reclaim+0x240/0x240 kthread+0x11f/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x24/0x30 Disabling lock debugging due to kernel taint .... The failures are from anyway that frees pages and empties the per-cpu page magazines, so it's not a predictable failure or an easy to debug failure. generic/038 is a reliable reproducer of this problem - it has a 9 in 10 failure rate on one of my test machines. Failure on other machines have been at random points in fstests runs but every run has ended up tripping this problem. Hence generic/038 was used to bisect the failure because it was the most reliable failure. It is too close to the 4.20 release (not to mention holidays) to try to diagnose, fix and test the underlying cause of the problem, so reverting the commit is the only option we have right now. The revert has been tested against a current tot 4.20-rc7+ kernel across multiple machines running sub-page block size XFs filesystems and none of the bad page state failures have been seen. Signed-off-by: Dave Chinner Cc: Piotr Jaroszynski Cc: Christoph Hellwig Cc: William Kucharski Cc: Darrick J. Wong Cc: Brian Foster Signed-off-by: Linus Torvalds

smb3: Fix rmdir compounding regression to strict servers

2018-12-19T13:55:32Z

Some servers require that the setinfo matches the exact size, and in this case compounding changes introduced by commit c2e0fe3f5aae ("cifs: make rmdir() use compounding") caused us to send 8 bytes (padded length) instead of 1 byte (the size of the structure). See MS-FSCC section 2.4.11. Fixing this when we send a SET_INFO command for delete file disposition, then ends up as an iov of a single byte but this causes problems with SMB3 and encryption. To avoid this, instead of creating a one byte iov for the disposition value and then appending an additional iov with a 7 byte padding we now handle this as a single 8 byte iov containing both the disposition byte as well as the padding in one single buffer. Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French Acked-by: Paulo Alcantara

Merge branch 'akpm' (patches from Andrew)

2018-12-14T23:35:30Z

Merge misc fixes from Andrew Morton: "11 fixes" * emailed patches from Andrew Morton : scripts/spdxcheck.py: always open files in binary mode checkstack.pl: fix for aarch64 userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered fs/iomap.c: get/put the page in iomap_page_create/release() hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page() memblock: annotate memblock_is_reserved() with __init_memblock psi: fix reference to kernel commandline enable arch/sh/include/asm/io.h: provide prototypes for PCI I/O mapping in asm/io.h mm/sparse: add common helper to mark all memblocks present mm: introduce common STRUCT_PAGE_MAX_SHIFT define alpha: fix hang caused by the bootmem removal

userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered

2018-12-14T23:05:45Z

Calling UFFDIO_UNREGISTER on virtual ranges not yet registered in uffd could trigger an harmless false positive WARN_ON. Check the vma is already registered before checking VM_MAYWRITE to shut off the false positive warning. Link: http://lkml.kernel.org/r/20181206212028.18726-2-aarcange@redhat.com Cc: Fixes: 29ec90660d68 ("userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas") Signed-off-by: Andrea Arcangeli Reported-by: syzbot+06c7092e7d71218a2c16@syzkaller.appspotmail.com Acked-by: Mike Rapoport Acked-by: Hugh Dickins Acked-by: Peter Xu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/iomap.c: get/put the page in iomap_page_create/release()

2018-12-14T23:05:45Z

migrate_page_move_mapping() expects pages with private data set to have a page_count elevated by 1. This is what used to happen for xfs through the buffer_heads code before the switch to iomap in commit 82cb14175e7d ("xfs: add support for sub-pagesize writeback without buffer_heads"). Not having the count elevated causes move_pages() to fail on memory mapped files coming from xfs. Make iomap compatible with the migrate_page_move_mapping() assumption by elevating the page count as part of iomap_page_create() and lowering it in iomap_page_release(). It causes the move_pages() syscall to misbehave on memory mapped files from xfs. It does not not move any pages, which I suppose is "just" a perf issue, but it also ends up returning a positive number which is out of spec for the syscall. Talking to Michal Hocko, it sounds like returning positive numbers might be a necessary update to move_pages() anyway though (https://lkml.kernel.org/r/20181116114955.GJ14706@dhcp22.suse.cz). I only hit this in tests that verify that move_pages() actually moved the pages. The test also got confused by the positive return from move_pages() (it got treated as a success as positive numbers were not expected and not handled) making it a bit harder to track down what's going on. Link: http://lkml.kernel.org/r/20181115184140.1388751-1-pjaroszynski@nvidia.com Fixes: 82cb14175e7d ("xfs: add support for sub-pagesize writeback without buffer_heads") Signed-off-by: Piotr Jaroszynski Reviewed-by: Christoph Hellwig Cc: William Kucharski Cc: Darrick J. Wong Cc: Brian Foster Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'for-linus-20181214' of git://git.kernel.dk/linux-block

2018-12-14T20:18:30Z

Pull block fixes from Jens Axboe: "Three small fixes for this week. contains: - spectre indexing fix for aio (Jeff) - fix for the previous zeroing bio fix, we don't need it for user mapped pages, and in fact it breaks some applications if we do (Keith) - allocation failure fix for null_blk with zoned (Shin'ichiro)" * tag 'for-linus-20181214' of git://git.kernel.dk/linux-block: block: Fix null_blk_zoned creation failure with small number of zones aio: fix spectre gadget in lookup_ioctx block/bio: Do not zero user pages