1. 30 Mar, 2020 8 commits
    • Linus Torvalds's avatar
      Merge tag 'erofs-for-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs · 377ad0c2
      Linus Torvalds authored
      Pull erofs updates from Gao Xiang:
       "Updates with a XArray adaptation, several fixes for shrinker and
        corrupted images are ready for this cycle.
      
        All commits have been stress tested with no noticeable smoke out and
        have been in linux-next as well.
      
        Summary:
      
         - Convert radix tree usage to XArray
      
         - Fix shrink scan count on multiple filesystem instances
      
         - Better handling for specific corrupted images
      
         - Update my email address in MAINTAINERS"
      
      * tag 'erofs-for-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
        MAINTAINERS: erofs: update my email address
        erofs: handle corrupted images whose decompressed size less than it'd be
        erofs: use LZ4_decompress_safe() for full decoding
        erofs: correct the remaining shrink objects
        erofs: convert workstn to XArray
      377ad0c2
    • Linus Torvalds's avatar
      Merge tag 'docs-5.7' of git://git.lwn.net/linux · 481ed297
      Linus Torvalds authored
      Pull documentation updates from Jonathan Corbet:
       "This has been a busy cycle for documentation work.
      
        Highlights include:
      
         - Lots of RST conversion work by Mauro, Daniel ALmeida, and others.
           Maybe someday we'll get to the end of this stuff...maybe...
      
         - Some organizational work to bring some order to the core-api
           manual.
      
         - Various new docs and additions to the existing documentation.
      
         - Typo fixes, warning fixes, ..."
      
      * tag 'docs-5.7' of git://git.lwn.net/linux: (123 commits)
        Documentation: x86: exception-tables: document CONFIG_BUILDTIME_TABLE_SORT
        MAINTAINERS: adjust to filesystem doc ReST conversion
        docs: deprecated.rst: Add BUG()-family
        doc: zh_CN: add translation for virtiofs
        doc: zh_CN: index files in filesystems subdirectory
        docs: locking: Drop :c:func: throughout
        docs: locking: Add 'need' to hardirq section
        docs: conf.py: avoid thousands of duplicate label warning on Sphinx
        docs: prevent warnings due to autosectionlabel
        docs: fix reference to core-api/namespaces.rst
        docs: fix pointers to io-mapping.rst and io_ordering.rst files
        Documentation: Better document the softlockup_panic sysctl
        docs: hw-vuln: tsx_async_abort.rst: get rid of an unused ref
        docs: perf: imx-ddr.rst: get rid of a warning
        docs: filesystems: fuse.rst: supress a Sphinx warning
        docs: translations: it: avoid duplicate refs at programming-language.rst
        docs: driver.rst: supress two ReSt warnings
        docs: trace: events.rst: convert some new stuff to ReST format
        Documentation: Add io_ordering.rst to driver-api manual
        Documentation: Add io-mapping.rst to driver-api manual
        ...
      481ed297
    • Linus Torvalds's avatar
      Merge tag 'for-5.7/io_uring-2020-03-29' of git://git.kernel.dk/linux-block · e59cd880
      Linus Torvalds authored
      Pull io_uring updates from Jens Axboe:
       "Here are the io_uring changes for this merge window. Light on new
        features this time around (just splice + buffer selection), lots of
        cleanups, fixes, and improvements to existing support. In particular,
        this contains:
      
         - Cleanup fixed file update handling for stack fallback (Hillf)
      
         - Re-work of how pollable async IO is handled, we no longer require
           thread offload to handle that. Instead we rely using poll to drive
           this, with task_work execution.
      
         - In conjunction with the above, allow expendable buffer selection,
           so that poll+recv (for example) no longer has to be a split
           operation.
      
         - Make sure we honor RLIMIT_FSIZE for buffered writes
      
         - Add support for splice (Pavel)
      
         - Linked work inheritance fixes and optimizations (Pavel)
      
         - Async work fixes and cleanups (Pavel)
      
         - Improve io-wq locking (Pavel)
      
         - Hashed link write improvements (Pavel)
      
         - SETUP_IOPOLL|SETUP_SQPOLL improvements (Xiaoguang)"
      
      * tag 'for-5.7/io_uring-2020-03-29' of git://git.kernel.dk/linux-block: (54 commits)
        io_uring: cleanup io_alloc_async_ctx()
        io_uring: fix missing 'return' in comment
        io-wq: handle hashed writes in chains
        io-uring: drop 'free_pfile' in struct io_file_put
        io-uring: drop completion when removing file
        io_uring: Fix ->data corruption on re-enqueue
        io-wq: close cancel gap for hashed linked work
        io_uring: make spdxcheck.py happy
        io_uring: honor original task RLIMIT_FSIZE
        io-wq: hash dependent work
        io-wq: split hashing and enqueueing
        io-wq: don't resched if there is no work
        io-wq: remove duplicated cancel code
        io_uring: fix truncated async read/readv and write/writev retry
        io_uring: dual license io_uring.h uapi header
        io_uring: io_uring_enter(2) don't poll while SETUP_IOPOLL|SETUP_SQPOLL enabled
        io_uring: Fix unused function warnings
        io_uring: add end-of-bits marker and build time verify it
        io_uring: provide means of removing buffers
        io_uring: add IOSQE_BUFFER_SELECT support for IORING_OP_RECVMSG
        ...
      e59cd880
    • Linus Torvalds's avatar
      Merge tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block · 15926148
      Linus Torvalds authored
      Pull block driver updates from Jens Axboe:
      
       - floppy driver cleanup series from Willy
      
       - NVMe updates and fixes (Various)
      
       - null_blk trace improvements (Chaitanya)
      
       - bcache fixes (Coly)
      
       - md fixes (via Song)
      
       - loop block size change optimizations (Martijn)
      
       - scnprintf() use (Takashi)
      
      * tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block: (81 commits)
        null_blk: add trace in null_blk_zoned.c
        null_blk: add tracepoint helpers for zoned mode
        block: add a zone condition debug helper
        nvme: cleanup namespace identifier reporting in nvme_init_ns_head
        nvme: rename __nvme_find_ns_head to nvme_find_ns_head
        nvme: refactor nvme_identify_ns_descs error handling
        nvme-tcp: Add warning on state change failure at nvme_tcp_setup_ctrl
        nvme-rdma: Add warning on state change failure at nvme_rdma_setup_ctrl
        nvme: Fix controller creation races with teardown flow
        nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl
        nvme: Fix ctrl use-after-free during sysfs deletion
        nvme-pci: Re-order nvme_pci_free_ctrl
        nvme: Remove unused return code from nvme_delete_ctrl_sync
        nvme: Use nvme_state_terminal helper
        nvme: release ida resources
        nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO
        nvmet-tcp: optimize tcp stack TX when data digest is used
        nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow
        nvme-multipath: do not reset on unknown status
        nvmet-rdma: allocate RW ctxs according to mdts
        ...
      15926148
    • Linus Torvalds's avatar
      Merge tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block · 10f36b1e
      Linus Torvalds authored
      Pull block updates from Jens Axboe:
      
       - Online capacity resizing (Balbir)
      
       - Number of hardware queue change fixes (Bart)
      
       - null_blk fault injection addition (Bart)
      
       - Cleanup of queue allocation, unifying the node/no-node API
         (Christoph)
      
       - Cleanup of genhd, moving code to where it makes sense (Christoph)
      
       - Cleanup of the partition handling code (Christoph)
      
       - disk stat fixes/improvements (Konstantin)
      
       - BFQ improvements (Paolo)
      
       - Various fixes and improvements
      
      * tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
        block: return NULL in blk_alloc_queue() on error
        block: move bio_map_* to blk-map.c
        Revert "blkdev: check for valid request queue before issuing flush"
        block: simplify queue allocation
        bcache: pass the make_request methods to blk_queue_make_request
        null_blk: use blk_mq_init_queue_data
        block: add a blk_mq_init_queue_data helper
        block: move the ->devnode callback to struct block_device_operations
        block: move the part_stat* helpers from genhd.h to a new header
        block: move block layer internals out of include/linux/genhd.h
        block: move guard_bio_eod to bio.c
        block: unexport get_gendisk
        block: unexport disk_map_sector_rcu
        block: unexport disk_get_part
        block: mark part_in_flight and part_in_flight_rw static
        block: mark block_depr static
        block: factor out requeue handling from dispatch code
        block/diskstats: replace time_in_queue with sum of request times
        block/diskstats: accumulate all per-cpu counters in one pass
        block/diskstats: more accurate approximation of io_ticks for slow disks
        ...
      10f36b1e
    • Linus Torvalds's avatar
      Merge tag 'for-5.7/libata-2020-03-29' of git://git.kernel.dk/linux-block · 3a0eb192
      Linus Torvalds authored
      Pull libata updates from Jens Axboe:
      
       - Series from Bart, making the libata code smaller on PATA only setups.
         This is useful for smaller/embedded use cases, and will help us move
         some of those off drivers/ide.
      
       - Kill unused BPRINTK() (Hannes)
      
       - Add various Comet Lake ahci PCI ids (Kai-Heng, Mika)
      
       - Fix for a double scsi_host_put() in error handling (John)
      
       - Use scnprintf (Takashi)
      
       - Assign OF node to the SCSI device (Linus Walleij)
      
      * tag 'for-5.7/libata-2020-03-29' of git://git.kernel.dk/linux-block: (36 commits)
        ata: make "libata.force" kernel parameter optional
        ata: move ata_eh_analyze_ncq_error() & co. to libata-sata.c
        ata: start separating SATA specific code from libata-eh.c
        ata: move ata_sas_*() to libata-sata.c
        ata: start separating SATA specific code from libata-scsi.c
        ata: move sata_deb_timing_*() to libata-sata.c
        ata: move ata_qc_complete_multiple() to libata-sata.c
        ata: move sata_link_hardreset() to libata-sata.c
        ata: move sata_link_{debounce,resume}() to libata-sata.c
        ata: move *sata_set_spd*() to libata-sata.c
        ata: move sata_scr_*() to libata-sata.c
        ata: start separating SATA specific code from libata-core.c
        ata: let compiler optimize out ata_eh_set_lpm() on non-SATA hosts
        ata: let compiler optimize out ata_dev_config_ncq() on non-SATA hosts
        ata: add CONFIG_SATA_HOST=n version of ata_ncq_enabled()
        ata: separate PATA timings code from libata-core.c
        ata: fix CodingStyle issues in PATA timings code
        ata: remove EXPORT_SYMBOL_GPL()s not used by modules
        ata: move EXPORT_SYMBOL_GPL()s close to exported code
        ata: optimize ata_scsi_rbuf[] size
        ...
      3a0eb192
    • Linus Torvalds's avatar
      Merge tag 'i3c/for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux · c03cb664
      Linus Torvalds authored
      Pull i3c updates from Boris Brezillon:
      
       - Fix driver auto-probing related issues
      
       - Stop using the deprecated i2c_new_device() function
      
       - Replace zero-length array with flexible-array member
      
      * tag 'i3c/for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
        i3c: convert to use i2c_new_client_device()
        i3c: master: Replace zero-length array with flexible-array member
        i3c: Simplify i3c_device_match_id()
        i3c: Generate aliases for i3c modules
        i3c: Add a modalias sysfs attribute
        i3c: Fix MODALIAS uevents
        i3c: master: no need to iterate master device twice
      c03cb664
    • Linus Torvalds's avatar
      Merge tag 'tpmdd-next-20200316' of git://git.infradead.org/users/jjs/linux-tpmdd · 0f751396
      Linus Torvalds authored
      Pull tpm updates from Jarkko Sakkinen:
       "tpmdd updates for Linux v5.7"
      
      * tag 'tpmdd-next-20200316' of git://git.infradead.org/users/jjs/linux-tpmdd:
        KEYS: reaching the keys quotas correctly
        tpm: ibmvtpm: Add support for TPM2
        tpm: ibmvtpm: Wait for buffer to be set before proceeding
        tpm: of: Handle IBM,vtpm20 case when getting log parameters
        MAINTAINERS: adjust to trusted keys subsystem creation
        tpm: tpm_tis_spi_cr50: use new structure for SPI transfer delays
        tpm_tis_spi: use new 'delay' structure for SPI transfer delays
        tpm: tpm2_bios_measurements_next should increase position index
        tpm: tpm1_bios_measurements_next should increase position index
        tpm: Don't make log failures fatal
      0f751396
  2. 29 Mar, 2020 12 commits
    • Linus Torvalds's avatar
      Linux 5.6 · 7111951b
      Linus Torvalds authored
      7111951b
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · 570203ec
      Linus Torvalds authored
      Merge vm fixes from Andrew Morton:
       "5 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        mm/sparse: fix kernel crash with pfn_section_valid check
        mm: fork: fix kernel_stack memcg stats for various stack implementations
        hugetlb_cgroup: fix illegal access to memory
        drivers/base/memory.c: indicate all memory blocks as removable
        mm/swapfile.c: move inode_lock out of claim_swapfile
      570203ec
    • Linus Torvalds's avatar
      Merge tag 'timers-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · ab93e984
      Linus Torvalds authored
      Pull timer fix from Thomas Gleixner:
       "A single fix for the Hyper-V clocksource driver to make sched clock
        actually return nanoseconds and not the virtual clock value which
        increments at 10e7 HZ (100ns)"
      
      * tag 'timers-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        clocksource/drivers/hyper-v: Make sched clock return nanoseconds correctly
      ab93e984
    • Linus Torvalds's avatar
      Merge tag 'irq-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 01af08bd
      Linus Torvalds authored
      Pull irq fix from Thomas Gleixner:
       "A single bugfix to prevent reference leaks in irq affinity notifiers"
      
      * tag 'irq-urgent-2020-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        genirq: Fix reference leaks on irq affinity notifiers
      01af08bd
    • Aneesh Kumar K.V's avatar
      mm/sparse: fix kernel crash with pfn_section_valid check · b943f045
      Aneesh Kumar K.V authored
      Fix the crash like this:
      
          BUG: Kernel NULL pointer dereference on read at 0x00000000
          Faulting instruction address: 0xc000000000c3447c
          Oops: Kernel access of bad area, sig: 11 [#1]
          LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
          CPU: 11 PID: 7519 Comm: lt-ndctl Not tainted 5.6.0-rc7-autotest #1
          ...
          NIP [c000000000c3447c] vmemmap_populated+0x98/0xc0
          LR [c000000000088354] vmemmap_free+0x144/0x320
          Call Trace:
             section_deactivate+0x220/0x240
             __remove_pages+0x118/0x170
             arch_remove_memory+0x3c/0x150
             memunmap_pages+0x1cc/0x2f0
             devm_action_release+0x30/0x50
             release_nodes+0x2f8/0x3e0
             device_release_driver_internal+0x168/0x270
             unbind_store+0x130/0x170
             drv_attr_store+0x44/0x60
             sysfs_kf_write+0x68/0x80
             kernfs_fop_write+0x100/0x290
             __vfs_write+0x3c/0x70
             vfs_write+0xcc/0x240
             ksys_write+0x7c/0x140
             system_call+0x5c/0x68
      
      The crash is due to NULL dereference at
      
      	test_bit(idx, ms->usage->subsection_map);
      
      due to ms->usage = NULL in pfn_section_valid()
      
      With commit d41e2f3b ("mm/hotplug: fix hot remove failure in
      SPARSEMEM|!VMEMMAP case") section_mem_map is set to NULL after
      depopulate_section_mem().  This was done so that pfn_page() can work
      correctly with kernel config that disables SPARSEMEM_VMEMMAP.  With that
      config pfn_to_page does
      
      	__section_mem_map_addr(__sec) + __pfn;
      
      where
      
        static inline struct page *__section_mem_map_addr(struct mem_section *section)
        {
      	unsigned long map = section->section_mem_map;
      	map &= SECTION_MAP_MASK;
      	return (struct page *)map;
        }
      
      Now with SPASEMEM_VMEMAP enabled, mem_section->usage->subsection_map is
      used to check the pfn validity (pfn_valid()).  Since section_deactivate
      release mem_section->usage if a section is fully deactivated,
      pfn_valid() check after a subsection_deactivate cause a kernel crash.
      
        static inline int pfn_valid(unsigned long pfn)
        {
        ...
      	return early_section(ms) || pfn_section_valid(ms, pfn);
        }
      
      where
      
        static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
        {
      	int idx = subsection_map_index(pfn);
      
      	return test_bit(idx, ms->usage->subsection_map);
        }
      
      Avoid this by clearing SECTION_HAS_MEM_MAP when mem_section->usage is
      freed.  For architectures like ppc64 where large pages are used for
      vmmemap mapping (16MB), a specific vmemmap mapping can cover multiple
      sections.  Hence before a vmemmap mapping page can be freed, the kernel
      needs to make sure there are no valid sections within that mapping.
      Clearing the section valid bit before depopulate_section_memap enables
      this.
      
      [aneesh.kumar@linux.ibm.com: add comment]
        Link: http://lkml.kernel.org/r/20200326133235.343616-1-aneesh.kumar@linux.ibm.comLink: http://lkml.kernel.org/r/20200325031914.107660-1-aneesh.kumar@linux.ibm.com
      Fixes: d41e2f3b ("mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case")
      Reported-by: default avatarSachin Sant <sachinp@linux.vnet.ibm.com>
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Tested-by: default avatarSachin Sant <sachinp@linux.vnet.ibm.com>
      Reviewed-by: default avatarBaoquan He <bhe@redhat.com>
      Reviewed-by: default avatarWei Yang <richard.weiyang@gmail.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarPankaj Gupta <pankaj.gupta.linux@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: David Hildenbrand <david@redhat.com>
      Cc: Oscar Salvador <osalvador@suse.de>
      Cc: Mike Rapoport <rppt@linux.ibm.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b943f045
    • Roman Gushchin's avatar
      mm: fork: fix kernel_stack memcg stats for various stack implementations · 8380ce47
      Roman Gushchin authored
      Depending on CONFIG_VMAP_STACK and the THREAD_SIZE / PAGE_SIZE ratio the
      space for task stacks can be allocated using __vmalloc_node_range(),
      alloc_pages_node() and kmem_cache_alloc_node().
      
      In the first and the second cases page->mem_cgroup pointer is set, but
      in the third it's not: memcg membership of a slab page should be
      determined using the memcg_from_slab_page() function, which looks at
      page->slab_cache->memcg_params.memcg .  In this case, using
      mod_memcg_page_state() (as in account_kernel_stack()) is incorrect:
      page->mem_cgroup pointer is NULL even for pages charged to a non-root
      memory cgroup.
      
      It can lead to kernel_stack per-memcg counters permanently showing 0 on
      some architectures (depending on the configuration).
      
      In order to fix it, let's introduce a mod_memcg_obj_state() helper,
      which takes a pointer to a kernel object as a first argument, uses
      mem_cgroup_from_obj() to get a RCU-protected memcg pointer and calls
      mod_memcg_state().  It allows to handle all possible configurations
      (CONFIG_VMAP_STACK and various THREAD_SIZE/PAGE_SIZE values) without
      spilling any memcg/kmem specifics into fork.c .
      
      Note: This is a special version of the patch created for stable
      backports.  It contains code from the following two patches:
        - mm: memcg/slab: introduce mem_cgroup_from_obj()
        - mm: fork: fix kernel_stack memcg stats for various stack implementations
      
      [guro@fb.com: introduce mem_cgroup_from_obj()]
        Link: http://lkml.kernel.org/r/20200324004221.GA36662@carbon.dhcp.thefacebook.com
      Fixes: 4d96ba35 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages")
      Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Bharata B Rao <bharata@linux.ibm.com>
      Cc: Shakeel Butt <shakeelb@google.com>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200303233550.251375-1-guro@fb.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8380ce47
    • Mina Almasry's avatar
      hugetlb_cgroup: fix illegal access to memory · 726b7bbe
      Mina Almasry authored
      This appears to be a mistake in commit faced7e0 ("mm: hugetlb
      controller for cgroups v2").
      
      Essentially that commit does a hugetlb_cgroup_from_counter assuming that
      page_counter_try_charge has initialized counter.
      
      But if that has failed then it seems will not initialize counter, so
      hugetlb_cgroup_from_counter(counter) ends up pointing to random memory,
      causing kasan to complain.
      
      The solution is to simply use 'h_cg', instead of
      hugetlb_cgroup_from_counter(counter), since that is a reference to the
      hugetlb_cgroup anyway.  After this change kasan ceases to complain.
      
      Fixes: faced7e0 ("mm: hugetlb controller for cgroups v2")
      Reported-by: syzbot+cac0c4e204952cf449b1@syzkaller.appspotmail.com
      Signed-off-by: default avatarMina Almasry <almasrymina@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Acked-by: default avatarGiuseppe Scrivano <gscrivan@redhat.com>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Mike Kravetz <mike.kravetz@oracle.com>
      Cc: David Rientjes <rientjes@google.com>
      Link: http://lkml.kernel.org/r/20200313223920.124230-1-almasrymina@google.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      726b7bbe
    • David Hildenbrand's avatar
      drivers/base/memory.c: indicate all memory blocks as removable · 53cdc1cb
      David Hildenbrand authored
      We see multiple issues with the implementation/interface to compute
      whether a memory block can be offlined (exposed via
      /sys/devices/system/memory/memoryX/removable) and would like to simplify
      it (remove the implementation).
      
      1. It runs basically lockless. While this might be good for performance,
         we see possible races with memory offlining that will require at
         least some sort of locking to fix.
      
      2. Nowadays, more false positives are possible. No arch-specific checks
         are performed that validate if memory offlining will not be denied
         right away (and such check will require locking). For example, arm64
         won't allow to offline any memory block that was added during boot -
         which will imply a very high error rate. Other archs have other
         constraints.
      
      3. The interface is inherently racy. E.g., if a memory block is detected
         to be removable (and was not a false positive at that time), there is
         still no guarantee that offlining will actually succeed. So any
         caller already has to deal with false positives.
      
      4. It is unclear which performance benefit this interface actually
         provides. The introducing commit 5c755e9f ("memory-hotplug: add
         sysfs removable attribute for hotplug memory remove") mentioned
      
      	"A user-level agent must be able to identify which sections
      	 of memory are likely to be removable before attempting the
      	 potentially expensive operation."
      
         However, no actual performance comparison was included.
      
      Known users:
      
       - lsmem: Will group memory blocks based on the "removable" property. [1]
      
       - chmem: Indirect user. It has a RANGE mode where one can specify
                removable ranges identified via lsmem to be offlined. However,
                it also has a "SIZE" mode, which allows a sysadmin to skip the
                manual "identify removable blocks" step. [2]
      
       - powerpc-utils: Uses the "removable" attribute to skip some memory
                blocks right away when trying to find some to offline+remove.
                However, with ballooning enabled, it already skips this
                information completely (because it once resulted in many false
                negatives). Therefore, the implementation can deal with false
                positives properly already. [3]
      
      According to Nathan Fontenot, DLPAR on powerpc is nowadays no longer
      driven from userspace via the drmgr command (powerpc-utils).  Nowadays
      it's managed in the kernel - including onlining/offlining of memory
      blocks - triggered by drmgr writing to /sys/kernel/dlpar.  So the
      affected legacy userspace handling is only active on old kernels.  Only
      very old versions of drmgr on a new kernel (unlikely) might execute
      slower - totally acceptable.
      
      With CONFIG_MEMORY_HOTREMOVE, always indicating "removable" should not
      break any user space tool.  We implement a very bad heuristic now.
      Without CONFIG_MEMORY_HOTREMOVE we cannot offline anything, so report
      "not removable" as before.
      
      Original discussion can be found in [4] ("[PATCH RFC v1] mm:
      is_mem_section_removable() overhaul").
      
      Other users of is_mem_section_removable() will be removed next, so that
      we can remove is_mem_section_removable() completely.
      
      [1] http://man7.org/linux/man-pages/man1/lsmem.1.html
      [2] http://man7.org/linux/man-pages/man8/chmem.8.html
      [3] https://github.com/ibm-power-utilities/powerpc-utils
      [4] https://lkml.kernel.org/r/20200117105759.27905-1-david@redhat.com
      
      Also, this patch probably fixes a crash reported by Steve.
      http://lkml.kernel.org/r/CAPcyv4jpdaNvJ67SkjyUJLBnBnXXQv686BiVW042g03FUmWLXw@mail.gmail.comReported-by: default avatar"Scargall, Steve" <steve.scargall@intel.com>
      Suggested-by: default avatarMichal Hocko <mhocko@kernel.org>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatarNathan Fontenot <ndfont@gmail.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: "Rafael J. Wysocki" <rafael@kernel.org>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Karel Zak <kzak@redhat.com>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200128093542.6908-1-david@redhat.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      53cdc1cb
    • Naohiro Aota's avatar
      mm/swapfile.c: move inode_lock out of claim_swapfile · d795a90e
      Naohiro Aota authored
      claim_swapfile() currently keeps the inode locked when it is successful,
      or the file is already swapfile (with -EBUSY).  And, on the other error
      cases, it does not lock the inode.
      
      This inconsistency of the lock state and return value is quite confusing
      and actually causing a bad unlock balance as below in the "bad_swap"
      section of __do_sys_swapon().
      
      This commit fixes this issue by moving the inode_lock() and IS_SWAPFILE
      check out of claim_swapfile().  The inode is unlocked in
      "bad_swap_unlock_inode" section, so that the inode is ensured to be
      unlocked at "bad_swap".  Thus, error handling codes after the locking now
      jumps to "bad_swap_unlock_inode" instead of "bad_swap".
      
          =====================================
          WARNING: bad unlock balance detected!
          5.5.0-rc7+ #176 Not tainted
          -------------------------------------
          swapon/4294 is trying to release lock (&sb->s_type->i_mutex_key) at: __do_sys_swapon+0x94b/0x3550
          but there are no more locks to release!
      
          other info that might help us debug this:
          no locks held by swapon/4294.
      
          stack backtrace:
          CPU: 5 PID: 4294 Comm: swapon Not tainted 5.5.0-rc7-BTRFS-ZNS+ #176
          Hardware name: ASUS All Series/H87-PRO, BIOS 2102 07/29/2014
          Call Trace:
           dump_stack+0xa1/0xea
           print_unlock_imbalance_bug.cold+0x114/0x123
           lock_release+0x562/0xed0
           up_write+0x2d/0x490
           __do_sys_swapon+0x94b/0x3550
           __x64_sys_swapon+0x54/0x80
           do_syscall_64+0xa4/0x4b0
           entry_SYSCALL_64_after_hwframe+0x49/0xbe
          RIP: 0033:0x7f15da0a0dc7
      
      Fixes: 1638045c ("mm: set S_SWAPFILE on blockdev swap devices")
      Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Tested-by: default avatarQais Youef <qais.yousef@arm.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200206090132.154869-1-naohiro.aota@wdc.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d795a90e
    • Chaitanya Kulkarni's avatar
      block: return NULL in blk_alloc_queue() on error · 654a3667
      Chaitanya Kulkarni authored
      This patch fixes follwoing warning:
      
      block/blk-core.c: In function ‘blk_alloc_queue’:
      block/blk-core.c:558:10: warning: returning ‘int’ from a function with return type ‘struct request_queue *’ makes pointer from integer without a cast [-Wint-conversion]
         return -EINVAL;
      
      Fixes: 3d745ea5 ("block: simplify queue allocation")
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      654a3667
    • Wolfram Sang's avatar
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net · e595dd94
      Linus Torvalds authored
      Pull networking fixes from David Miller:
      
       1) Fix memory leak in vti6, from Torsten Hilbrich.
      
       2) Fix double free in xfrm_policy_timer, from YueHaibing.
      
       3) NL80211_ATTR_CHANNEL_WIDTH attribute is put with wrong type, from
          Johannes Berg.
      
       4) Wrong allocation failure check in qlcnic driver, from Xu Wang.
      
       5) Get ks8851-ml IO operations right, for real this time, from Marek
          Vasut.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (22 commits)
        r8169: fix PHY driver check on platforms w/o module softdeps
        net: ks8851-ml: Fix IO operations, again
        mlxsw: spectrum_mr: Fix list iteration in error path
        qlcnic: Fix bad kzalloc null test
        mac80211: set IEEE80211_TX_CTRL_PORT_CTRL_PROTO for nl80211 TX
        mac80211: mark station unauthorized before key removal
        mac80211: Check port authorization in the ieee80211_tx_dequeue() case
        cfg80211: Do not warn on same channel at the end of CSA
        mac80211: drop data frames without key on encrypted links
        ieee80211: fix HE SPR size calculation
        nl80211: fix NL80211_ATTR_CHANNEL_WIDTH attribute type
        xfrm: policy: Fix doulbe free in xfrm_policy_timer
        bpf: Explicitly memset some bpf info structures declared on the stack
        bpf: Explicitly memset the bpf_attr structure
        bpf: Sanitize the bpf_struct_ops tcp-cc name
        vti6: Fix memory leak of skb if input policy check fails
        esp: remove the skb from the chain when it's enqueued in cryptd_wq
        ipv6: xfrm6_tunnel.c: Use built-in RCU list checking
        xfrm: add the missing verify_sec_ctx_len check in xfrm_add_acquire
        xfrm: fix uctx len check in verify_sec_ctx_len
        ...
      e595dd94
  3. 28 Mar, 2020 5 commits
  4. 27 Mar, 2020 15 commits