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2017-06-15ufs: more deadlock prevention on tail unpackingAl Viro
->s_lock is not needed for ufs_change_blocknr() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-15ufs: avoid grabbing ->truncate_mutex if possibleAl Viro
tail unpacking is done in a wrong place; the deadlocks galore is best dealt with by doing that in ->write_iter() (and switching to iomap, while we are at it), but that's rather painful to backport. The trouble comes from grabbing pages that cover the beginning of tail from inside of ufs_new_fragments(); ongoing pageout of any of those is going to deadlock on ->truncate_mutex with process that got around to extending the tail holding that and waiting for page to get unlocked, while ->writepage() on that page is waiting on ->truncate_mutex. The thing is, we don't need ->truncate_mutex when the fragment we are trying to map is within the tail - the damn thing is allocated (tail can't contain holes). Let's do a plain lookup and if the fragment is present, we can just pretend that we'd won the race in almost all cases. The only exception is a fragment between the end of tail and the end of block containing tail. Protect ->i_lastfrag with ->meta_lock - read_seqlock_excl() is sufficient. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ufs_get_locked_page(): make sure we have buffer_headsAl Viro
callers rely upon that, but find_lock_page() racing with attempt of page eviction by memory pressure might have left us with * try_to_free_buffers() successfully done * __remove_mapping() failed, leaving the page in our mapping * find_lock_page() returning an uptodate page with no buffer_heads attached. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ufs: fix s_size/s_dsize usersAl Viro
For UFS2 we need 64bit variants; we even store them in uspi, but use 32bit ones instead. One wrinkle is in handling of reserved space - recalculating it every time had been stupid all along, but now it would become really ugly. Just calculate it once... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ufs: fix reserved blocks checkAl Viro
a) honour ->s_minfree; don't just go with default (5) b) don't bother with capability checks until we know we'll need them Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ufs: make ufs_freespace() return signedAl Viro
as it is, checking that its return value is <= 0 is useless and that's how it's being used. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ufs: fix logics in "ufs: make fsck -f happy"Al Viro
Storing stats _only_ at new locations is wrong for UFS1; old locations should always be kept updated. The check for "has been converted to use of new locations" is also wrong - it should be "->fs_maxbsize is equal to ->fs_bsize". Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-14ceph: unify inode i_ctime updateYan, Zheng
Current __ceph_setattr() can set inode's i_ctime to current_time(), req->r_stamp or attr->ia_ctime. These time stamps may have minor differences. It may cause potential problem. Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2017-06-14ceph: use current_kernel_time() to get request time stampYan, Zheng
ceph uses ktime_get_real_ts() to get request time stamp. In most other cases, current_kernel_time() is used to get time stamp for filesystem operations (called by current_time()). There is granularity difference between ktime_get_real_ts() and current_kernel_time(). The later one can be up to one jiffy behind the former one. This can causes inode's ctime to go back. Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2017-06-14ceph: check i_nlink while converting a file handle to dentryLuis Henriques
Converting a file handle to a dentry can be done call after the inode unlink. This means that __fh_to_dentry() requires an extra check to verify the number of links is not 0. The issue can be easily reproduced using xfstest generic/426, which does something like: name_to_handle_at(&fh) echo 3 > /proc/sys/vm/drop_caches unlink() open_by_handle_at(&fh) The call to open_by_handle_at() should fail, as the file doesn't exist anymore. Link: http://tracker.ceph.com/issues/19958 Signed-off-by: Luis Henriques <lhenriques@suse.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2017-06-12configfs: Introduce config_item_get_unless_zero()Bart Van Assche
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> [hch: minor style tweak] Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-12configfs: Fix race between create_link and configfs_rmdirNicholas Bellinger
This patch closes a long standing race in configfs between the creation of a new symlink in create_link(), while the symlink target's config_item is being concurrently removed via configfs_rmdir(). This can happen because the symlink target's reference is obtained by config_item_get() in create_link() before the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep() during configfs_rmdir() shutdown is actually checked.. This originally manifested itself on ppc64 on v4.8.y under heavy load using ibmvscsi target ports with Novalink API: [ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added [ 7879.893760] ------------[ cut here ]------------ [ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs] [ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G O 4.8.17-customv2.22 #12 [ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000 [ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870 [ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700 Tainted: G O (4.8.17-customv2.22) [ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28222242 XER: 00000000 [ 7879.893820] CFAR: d000000002c664bc SOFTE: 1 GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820 GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000 GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80 GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40 GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940 GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000 GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490 GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940 [ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs] [ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893842] Call Trace: [ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460 [ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490 [ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170 [ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390 [ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec [ 7879.893856] Instruction dump: [ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000 [ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000 [ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]--- To close this race, go ahead and obtain the symlink's target config_item reference only after the existing CONFIGFS_USET_DROPPING check succeeds. This way, if configfs_rmdir() wins create_link() will return -ENONET, and if create_link() wins configfs_rmdir() will return -EBUSY. Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org
2017-06-11Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Fix various bug fixes in ext4 caused by races and memory allocation failures" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix fdatasync(2) after extent manipulation operations ext4: fix data corruption for mmap writes ext4: fix data corruption with EXT4_GET_BLOCKS_ZERO ext4: fix quota charging for shared xattr blocks ext4: remove redundant check for encrypted file on dio write path ext4: remove unused d_name argument from ext4_search_dir() et al. ext4: fix off-by-one error when writing back pages before dio read ext4: fix off-by-one on max nr_pages in ext4_find_unwritten_pgoff() ext4: keep existing extra fields when inode expands ext4: handle the rest of ext4_mb_load_buddy() ENOMEM errors ext4: fix off-by-in in loop termination in ext4_find_unwritten_pgoff() ext4: fix SEEK_HOLE jbd2: preserve original nofs flag during journal restart ext4: clear lockdep subtype for quota files on quota off
2017-06-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull UFS fixes from Al Viro: "This is just the obvious backport fodder; I'm pretty sure that there will be more - definitely so wrt performance and quite possibly correctness as well" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ufs: we need to sync inode before freeing it excessive checks in ufs_write_failed() and ufs_evict_inode() ufs_getfrag_block(): we only grab ->truncate_mutex on block creation path ufs_extend_tail(): fix the braino in calling conventions of ufs_new_fragments() ufs: set correct ->s_maxsize ufs: restore maintaining ->i_blocks fix ufs_isblockset() ufs: restore proper tail allocation
2017-06-10Merge branch 'for-linus-4.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Some fixes that Dave Sterba collected. We've been hitting an early enospc problem on production machines that Omar tracked down to an old int->u64 mistake. I waited a bit on this pull to make sure it was really the problem from production, but it's on ~2100 hosts now and I think we're good. Omar also noticed a commit in the queue would make new early ENOSPC problems. I pulled that out for now, which is why the top three commits are younger than the rest. Otherwise these are all fixes, some explaining very old bugs that we've been poking at for a while" * 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix delalloc accounting leak caused by u32 overflow Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_io btrfs: tree-log.c: Wrong printk information about namelen btrfs: fix race with relocation recovery and fs_root setup btrfs: fix memory leak in update_space_info failure path btrfs: use correct types for page indices in btrfs_page_exists_in_range btrfs: fix incorrect error return ret being passed to mapping_set_error btrfs: Make flush bios explicitely sync btrfs: fiemap: Cache and merge fiemap extent before submit it to user
2017-06-10ufs: we need to sync inode before freeing itAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09excessive checks in ufs_write_failed() and ufs_evict_inode()Al Viro
As it is, short copy in write() to append-only file will fail to truncate the excessive allocated blocks. As the matter of fact, all checks in ufs_truncate_blocks() are either redundant or wrong for that caller. As for the only other caller (ufs_evict_inode()), we only need the file type checks there. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09ufs_getfrag_block(): we only grab ->truncate_mutex on block creation pathAl Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09ufs_extend_tail(): fix the braino in calling conventions of ufs_new_fragments()Al Viro
... and it really needs splitting into "new" and "extend" cases, but that's for later Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09ufs: set correct ->s_maxsizeAl Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09ufs: restore maintaining ->i_blocksAl Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09fix ufs_isblockset()Al Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09ufs: restore proper tail allocationAl Viro
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09Btrfs: fix delalloc accounting leak caused by u32 overflowOmar Sandoval
btrfs_calc_trans_metadata_size() does an unsigned 32-bit multiplication, which can overflow if num_items >= 4 GB / (nodesize * BTRFS_MAX_LEVEL * 2). For a nodesize of 16kB, this overflow happens at 16k items. Usually, num_items is a small constant passed to btrfs_start_transaction(), but we also use btrfs_calc_trans_metadata_size() for metadata reservations for extent items in btrfs_delalloc_{reserve,release}_metadata(). In drop_outstanding_extents(), num_items is calculated as inode->reserved_extents - inode->outstanding_extents. The difference between these two counters is usually small, but if many delalloc extents are reserved and then the outstanding extents are merged in btrfs_merge_extent_hook(), the difference can become large enough to overflow in btrfs_calc_trans_metadata_size(). The overflow manifests itself as a leak of a multiple of 4 GB in delalloc_block_rsv and the metadata bytes_may_use counter. This in turn can cause early ENOSPC errors. Additionally, these WARN_ONs in extent-tree.c will be hit when unmounting: WARN_ON(fs_info->delalloc_block_rsv.size > 0); WARN_ON(fs_info->delalloc_block_rsv.reserved > 0); WARN_ON(space_info->bytes_pinned > 0 || space_info->bytes_reserved > 0 || space_info->bytes_may_use > 0); Fix it by casting nodesize to a u64 so that btrfs_calc_trans_metadata_size() does a full 64-bit multiplication. While we're here, do the same in btrfs_calc_trunc_metadata_size(); this can't overflow with any existing uses, but it's better to be safe here than have another hard-to-debug problem later on. Cc: stable@vger.kernel.org Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-06-09Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_ioLiu Bo
Before this, we use 'filled' mode here, ie. if all range has been filled with EXTENT_DEFRAG bits, get to clear it, but if the defrag range joins the adjacent delalloc range, then we'll have EXTENT_DEFRAG bits in extent_state until releasing this inode's pages, and that prevents extent_data from being freed. This clears the bit if any was found within the ordered extent. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-06-09btrfs: tree-log.c: Wrong printk information about namelenSu Yue
In verify_dir_item, it wants to printk name_len of dir_item but printk data_len acutally. Fix it by calling btrfs_dir_name_len instead of btrfs_dir_data_len. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-06-08xfs: fix spurious spin_is_locked() assert failures on non-smp kernelsBrian Foster
The 0-day kernel test robot reports assertion failures on !CONFIG_SMP kernels due to failed spin_is_locked() checks. As it turns out, spin_is_locked() is hardcoded to return zero on !CONFIG_SMP kernels and so this function cannot be relied on to verify spinlock state in this configuration. To avoid this problem, replace the associated asserts with lockdep variants that do the right thing regardless of kernel configuration. Drop the one assert that checks for an unlocked lock as there is no suitable lockdep variant for that case. This moves the spinlock checks from XFS debug code to lockdep, but generally provides the same level of protection. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-08crypto: Work around deallocated stack frame reference gcc bug on sparc.David Miller
On sparc, if we have an alloca() like situation, as is the case with SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack memory. The result can be that the value is clobbered if a trap or interrupt arrives at just the right instruction. It only occurs if the function ends returning a value from that alloca() area and that value can be placed into the return value register using a single instruction. For example, in lib/libcrc32c.c:crc32c() we end up with a return sequence like: return %i7+8 lduw [%o5+16], %o0 ! MEM[(u32 *)__shash_desc.1_10 + 16B], %o5 holds the base of the on-stack area allocated for the shash descriptor. But the return released the stack frame and the register window. So if an intererupt arrives between 'return' and 'lduw', then the value read at %o5+16 can be corrupted. Add a data compiler barrier to work around this problem. This is exactly what the gcc fix will end up doing as well, and it absolutely should not change the code generated for other cpus (unless gcc on them has the same bug :-) With crucial insight from Eric Sandeen. Cc: <stable@vger.kernel.org> Reported-by: Anatoly Pugachev <matorola@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-05NFSv4.2: Don't send mode again in post-EXCLUSIVE4_1 SETATTR with umaskBenjamin Coddington
Now that we have umask support, we shouldn't re-send the mode in a SETATTR following an exclusive CREATE, or we risk having the same problem fixed in commit 5334c5bdac92 ("NFS: Send attributes in OPEN request for NFS4_CREATE_EXCLUSIVE4_1"), which is that files with S_ISGID will have that bit stripped away. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Fixes: dff25ddb4808 ("nfs: add support for the umask attribute") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-06-04fs/ufs: Set UFS default maximum bytes per fileRichard Narron
This fixes a problem with reading files larger than 2GB from a UFS-2 file system: https://bugzilla.kernel.org/show_bug.cgi?id=195721 The incorrect UFS s_maxsize limit became a problem as of commit c2a9737f45e2 ("vfs,mm: fix a dead loop in truncate_inode_pages_range()") which started using s_maxbytes to avoid a page index overflow in do_generic_file_read(). That caused files to be truncated on UFS-2 file systems because the default maximum file size is 2GB (MAX_NON_LFS) and UFS didn't update it. Here I simply increase the default to a common value used by other file systems. Signed-off-by: Richard Narron <comet.berkeley@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will B <will.brokenbourgh2877@gmail.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: <stable@vger.kernel.org> # v4.9 and backports of c2a9737f45e2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-04Merge tag 'nfs-for-4.12-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client bugfixes from Trond Myklebust: "Bugfixes include: - Fix a typo in commit e092693443b ("NFS append COMMIT after synchronous COPY") that breaks copy offload - Fix the connect error propagation in xs_tcp_setup_socket() - Fix a lock leak in nfs40_walk_client_list - Verify that pNFS requests lie within the offset range of the layout segment" * tag 'nfs-for-4.12-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: Mark unnecessarily extern functions as static SUNRPC: ensure correct error is reported by xs_tcp_setup_socket() NFSv4.0: Fix a lock leak in nfs40_walk_client_list pnfs: Fix the check for requests in range of layout segment xprtrdma: Delete an error message for a failed memory allocation in xprt_rdma_bc_setup() pNFS/flexfiles: missing error code in ff_layout_alloc_lseg() NFS fix COMMIT after COPY
2017-06-03nfs: Mark unnecessarily extern functions as staticJan Kara
nfs_initialise_sb() and nfs_clone_super() are declared as extern even though they are used only in fs/nfs/super.c. Mark them as static. Also remove explicit 'inline' directive from nfs_initialise_sb() and leave it upto compiler to decide whether inlining is worth it. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-06-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "15 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: scripts/gdb: make lx-dmesg command work (reliably) mm: consider memblock reservations for deferred memory initialization sizing mm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specified mlock: fix mlock count can not decrease in race condition mm/migrate: fix refcount handling when !hugepage_migration_supported() dax: fix race between colliding PMD & PTE entries mm: avoid spurious 'bad pmd' warning messages mm/page_alloc.c: make sure OOM victim can try allocations with no watermarks once pcmcia: remove left-over %Z format slub/memcg: cure the brainless abuse of sysfs attributes initramfs: fix disabling of initramfs (and its compression) mm: clarify why we want kmalloc before falling backto vmallock frv: declare jiffies to be located in the .data section include/linux/gfp.h: fix ___GFP_NOLOCKDEP value ksm: prevent crash after write_protect_page fails
2017-06-02dax: fix race between colliding PMD & PTE entriesRoss Zwisler
We currently have two related PMD vs PTE races in the DAX code. These can both be easily triggered by having two threads reading and writing simultaneously to the same private mapping, with the key being that private mapping reads can be handled with PMDs but private mapping writes are always handled with PTEs so that we can COW. Here is the first race: CPU 0 CPU 1 (private mapping write) __handle_mm_fault() create_huge_pmd() - FALLBACK handle_pte_fault() passes check for pmd_devmap() (private mapping read) __handle_mm_fault() create_huge_pmd() dax_iomap_pmd_fault() inserts PMD dax_iomap_pte_fault() does a PTE fault, but we already have a DAX PMD installed in our page tables at this spot. Here's the second race: CPU 0 CPU 1 (private mapping read) __handle_mm_fault() passes check for pmd_none() create_huge_pmd() dax_iomap_pmd_fault() inserts PMD (private mapping write) __handle_mm_fault() create_huge_pmd() - FALLBACK (private mapping read) __handle_mm_fault() passes check for pmd_none() create_huge_pmd() handle_pte_fault() dax_iomap_pte_fault() inserts PTE dax_iomap_pmd_fault() inserts PMD, but we already have a PTE at this spot. The core of the issue is that while there is isolation between faults to the same range in the DAX fault handlers via our DAX entry locking, there is no isolation between faults in the code in mm/memory.c. This means for instance that this code in __handle_mm_fault() can run: if (pmd_none(*vmf.pmd) && transparent_hugepage_enabled(vma)) { ret = create_huge_pmd(&vmf); But by the time we actually get to run the fault handler called by create_huge_pmd(), the PMD is no longer pmd_none() because a racing PTE fault has installed a normal PMD here as a parent. This is the cause of the 2nd race. The first race is similar - there is the following check in handle_pte_fault(): } else { /* See comment in pte_alloc_one_map() */ if (pmd_devmap(*vmf->pmd) || pmd_trans_unstable(vmf->pmd)) return 0; So if a pmd_devmap() PMD (a DAX PMD) has been installed at vmf->pmd, we will bail and retry the fault. This is correct, but there is nothing preventing the PMD from being installed after this check but before we actually get to the DAX PTE fault handlers. In my testing these races result in the following types of errors: BUG: Bad rss-counter state mm:ffff8800a817d280 idx:1 val:1 BUG: non-zero nr_ptes on freeing mm: 15 Fix this issue by having the DAX fault handlers verify that it is safe to continue their fault after they have taken an entry lock to block other racing faults. [ross.zwisler@linux.intel.com: improve fix for colliding PMD & PTE entries] Link: http://lkml.kernel.org/r/20170526195932.32178-1-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/20170522215749.23516-2-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Pawel Lebioda <pawel.lebioda@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Pawel Lebioda <pawel.lebioda@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Xiong Zhou <xzhou@redhat.com> Cc: Eryu Guan <eguan@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-02Merge tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull XFS fix from Darrick Wong: "I've one more bugfix for you for 4.12-rc4: Fix an unmount hang due to a race in io buffer accounting" * tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: use ->b_state to fix buffer I/O accounting release race
2017-06-01Merge tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd fixes from Bruce Fields: "Revert patch accidentally included in the merge window pull request, and fix a crash that was likely a result of buggy client behavior" * tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linux: nfsd4: fix null dereference on replay nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments"
2017-06-01Merge tag 'gcc-plugins-v4.12-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc-plugin prepwork from Kees Cook: "Use designated initializers for mtk-vcodec, powerplay, amdgpu, and sgi-xp. Use ERR_CAST() to avoid cross-structure cast in ocf2, ntfs, and NFS. Christoph Hellwig recommended that I send these fixes now, rather than waiting for the v4.13 merge window. These are all initializer and cast fixes needed for the future randstruct plugin that haven't been picked up by the respective maintainers" * tag 'gcc-plugins-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: mtk-vcodec: Use designated initializers drm/amd/powerplay: Use designated initializers drm/amdgpu: Use designated initializers sgi-xp: Use designated initializers ocfs2: Use ERR_CAST() to avoid cross-structure cast ntfs: Use ERR_CAST() to avoid cross-structure cast NFS: Use ERR_CAST() to avoid cross-structure cast
2017-06-01Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull Reiserfs and GFS2 fixes from Jan Kara: "Fixes to GFS2 & Reiserfs for the fallout of the recent WRITE_FUA cleanup from Christoph. Fixes for other filesystems were already merged by respective maintainers." * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: reiserfs: Make flush bios explicitely sync gfs2: Make flush bios explicitely sync
2017-06-01btrfs: fix race with relocation recovery and fs_root setupJeff Mahoney
If we have to recover relocation during mount, we'll ultimately have to evict the orphan inode. That goes through the reservation dance, where priority_reclaim_metadata_space and flush_space expect fs_info->fs_root to be valid. That's the next thing to be set up during mount, so we crash, almost always in flush_space trying to join the transaction but priority_reclaim_metadata_space is possible as well. This call path has been problematic in the past WRT whether ->fs_root is valid yet. Commit 957780eb278 (Btrfs: introduce ticketed enospc infrastructure) added new users that are called in the direct path instead of the async path that had already been worked around. The thing is that we don't actually need the fs_root, specifically, for anything. We either use it to determine whether the root is the chunk_root for use in choosing an allocation profile or as a root to pass btrfs_join_transaction before immediately committing it. Anything that isn't the chunk root works in the former case and any root works in the latter. A simple fix is to use a root we know will always be there: the extent_root. Cc: <stable@vger.kernel.org> # v4.8+ Fixes: 957780eb278 (Btrfs: introduce ticketed enospc infrastructure) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-01btrfs: fix memory leak in update_space_info failure pathJeff Mahoney
If we fail to add the space_info kobject, we'll leak the memory for the percpu counter. Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs) Cc: <stable@vger.kernel.org> # v3.14+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-01btrfs: use correct types for page indices in btrfs_page_exists_in_rangeDavid Sterba
Variables start_idx and end_idx are supposed to hold a page index derived from the file offsets. The int type is not the right one though, offsets larger than 1 << 44 will get silently trimmed off the high bits. (1 << 44 is 16TiB) What can go wrong, if start is below the boundary and end gets trimmed: - if there's a page after start, we'll find it (radix_tree_gang_lookup_slot) - the final check "if (page->index <= end_idx)" will unexpectedly fail The function will return false, ie. "there's no page in the range", although there is at least one. btrfs_page_exists_in_range is used to prevent races in: * in hole punching, where we make sure there are not pages in the truncated range, otherwise we'll wait for them to finish and redo truncation, but we're going to replace the pages with holes anyway so the only problem is the intermediate state * lock_extent_direct: we want to make sure there are no pages before we lock and start DIO, to prevent stale data reads For practical occurence of the bug, there are several constaints. The file must be quite large, the affected range must cross the 16TiB boundary and the internal state of the file pages and pending operations must match. Also, we must not have started any ordered data in the range, otherwise we don't even reach the buggy function check. DIO locking tries hard in several places to avoid deadlocks with buffered IO and avoids waiting for ranges. The worst consequence seems to be stale data read. CC: Liu Bo <bo.li.liu@oracle.com> CC: stable@vger.kernel.org # 3.16+ Fixes: fc4adbff823f7 ("btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking") Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-31Merge branch 'overlayfs-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs fixes from Miklos Szeredi: "Fix regressions: - missing CONFIG_EXPORTFS dependency - failure if upper fs doesn't support xattr - bad error cleanup This also adds the concept of "impure" directories complementing the "origin" marking introduced in -rc1. Together they enable getting consistent st_ino and d_ino for directory listings. And there's a bug fix and a cleanup as well" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: filter trusted xattr for non-admin ovl: mark upper merge dir with type origin entries "impure" ovl: mark upper dir with type origin entries "impure" ovl: remove unused arg from ovl_lookup_temp() ovl: handle rename when upper doesn't support xattr ovl: don't fail copy-up if upper doesn't support xattr ovl: check on mount time if upper fs supports setting xattr ovl: fix creds leak in copy up error path ovl: select EXPORTFS
2017-05-31xfs: use ->b_state to fix buffer I/O accounting release raceBrian Foster
We've had user reports of unmount hangs in xfs_wait_buftarg() that analysis shows is due to btp->bt_io_count == -1. bt_io_count represents the count of in-flight asynchronous buffers and thus should always be >= 0. xfs_wait_buftarg() waits for this value to stabilize to zero in order to ensure that all untracked (with respect to the lru) buffers have completed I/O processing before unmount proceeds to tear down in-core data structures. The value of -1 implies an I/O accounting decrement race. Indeed, the fact that xfs_buf_ioacct_dec() is called from xfs_buf_rele() (where the buffer lock is no longer held) means that bp->b_flags can be updated from an unsafe context. While a user-level reproducer is currently not available, some intrusive hacks to run racing buffer lookups/ioacct/releases from multiple threads was used to successfully manufacture this problem. Existing callers do not expect to acquire the buffer lock from xfs_buf_rele(). Therefore, we can not safely update ->b_flags from this context. It turns out that we already have separate buffer state bits and associated serialization for dealing with buffer LRU state in the form of ->b_state and ->b_lock. Therefore, replace the _XBF_IN_FLIGHT flag with a ->b_state variant, update the I/O accounting wrappers appropriately and make sure they are used with the correct locking. This ensures that buffer in-flight state can be modified at buffer release time without racing with modifications from a buffer lock holder. Fixes: 9c7504aa72b6 ("xfs: track and serialize in-flight async buffers against unmount") Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Libor Pechacek <lpechacek@suse.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-30"Yes, people use FOLL_FORCE ;)"Linus Torvalds
This effectively reverts commit 8ee74a91ac30 ("proc: try to remove use of FOLL_FORCE entirely") It turns out that people do depend on FOLL_FORCE for the /proc/<pid>/mem case, and we're talking not just debuggers. Talking to the affected people, the use-cases are: Keno Fischer: "We used these semantics as a hardening mechanism in the julia JIT. By opening /proc/self/mem and using these semantics, we could avoid needing RWX pages, or a dual mapping approach. We do have fallbacks to these other methods (though getting EIO here actually causes an assert in released versions - we'll updated that to make sure to take the fall back in that case). Nevertheless the /proc/self/mem approach was our favored approach because it a) Required an attacker to be able to execute syscalls which is a taller order than getting memory write and b) didn't double the virtual address space requirements (as a dual mapping approach would). I think in general this feature is very useful for anybody who needs to precisely control the execution of some other process. Various debuggers (gdb/lldb/rr) certainly fall into that category, but there's another class of such processes (wine, various emulators) which may want to do that kind of thing. Now, I suspect most of these will have the other process under ptrace control, so maybe allowing (same_mm || ptraced) would be ok, but at least for the sandbox/remote-jit use case, it would be perfectly reasonable to not have the jit server be a ptracer" Robert O'Callahan: "We write to readonly code and data mappings via /proc/.../mem in lots of different situations, particularly when we're adjusting program state during replay to match the recorded execution. Like Julia, we can add workarounds, but they could be expensive." so not only do people use FOLL_FORCE for both reads and writes, but they use it for both the local mm and remote mm. With these comments in mind, we likely also cannot add the "are we actively ptracing" check either, so this keeps the new code organization and does not do a real revert that would add back the original comment about "Maybe we should limit FOLL_FORCE to actual ptrace users?" Reported-by: Keno Fischer <keno@juliacomputing.com> Reported-by: Robert O'Callahan <robert@ocallahan.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-29ext4: fix fdatasync(2) after extent manipulation operationsJan Kara
Currently, extent manipulation operations such as hole punch, range zeroing, or extent shifting do not record the fact that file data has changed and thus fdatasync(2) has a work to do. As a result if we crash e.g. after a punch hole and fdatasync, user can still possibly see the punched out data after journal replay. Test generic/392 fails due to these problems. Fix the problem by properly marking that file data has changed in these operations. CC: stable@vger.kernel.org Fixes: a4bb6b64e39abc0e41ca077725f2a72c868e7622 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-29ovl: filter trusted xattr for non-adminMiklos Szeredi
Filesystems filter out extended attributes in the "trusted." domain for unprivlieged callers. Overlay calls underlying filesystem's method with elevated privs, so need to do the filtering in overlayfs too. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-29ovl: mark upper merge dir with type origin entries "impure"Amir Goldstein
An upper dir is marked "impure" to let ovl_iterate() know that this directory may contain non pure upper entries whose d_ino may need to be read from the origin inode. We already mark a non-merge dir "impure" when moving a non-pure child entry inside it, to let ovl_iterate() know not to iterate the non-merge dir directly. Mark also a merge dir "impure" when moving a non-pure child entry inside it and when copying up a child entry inside it. This can be used to optimize ovl_iterate() to perform a "pure merge" of upper and lower directories, merging the content of the directories, without having to read d_ino from origin inodes. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-28ocfs2: Use ERR_CAST() to avoid cross-structure castKees Cook
When trying to propagate an error result, the error return path attempts to retain the error, but does this with an open cast across very different types, which the upcoming structure layout randomization plugin flags as being potentially dangerous in the face of randomization. This is a false positive, but what this code actually wants to do is use ERR_CAST() to retain the error value. Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-05-28ntfs: Use ERR_CAST() to avoid cross-structure castKees Cook
When trying to propagate an error result, the error return path attempts to retain the error, but does this with an open cast across very different types, which the upcoming structure layout randomization plugin flags as being potentially dangerous in the face of randomization. This is a false positive, but what this code actually wants to do is use ERR_CAST() to retain the error value. Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-05-28NFS: Use ERR_CAST() to avoid cross-structure castKees Cook
When the call to nfs_devname() fails, the error path attempts to retain the error via the mnt variable, but this requires a cast across very different types (char * to struct vfsmount *), which the upcoming structure layout randomization plugin flags as being potentially dangerous in the face of randomization. This is a false positive, but what this code actually wants to do is retain the error value, so this patch explicitly sets it, instead of using what seems to be an unexpected cast. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de>