1. 27 Jan, 2019 1 commit
  2. 22 Jan, 2019 1 commit
    • Ming Lei's avatar
      block: cover another queue enter recursion via BIO_QUEUE_ENTERED · 698cef17
      Ming Lei authored
      Except for blk_queue_split(), bio_split() is used for splitting bio too,
      then the remained bio is often resubmit to queue via generic_make_request().
      So the same queue enter recursion exits in this case too. Unfortunatley
      commit cd4a4ae4 doesn't help this case.
      
      This patch covers the above case by setting BIO_QUEUE_ENTERED before calling
      q->make_request_fn.
      
      In theory the per-bio flag is used to simulate one stack variable, it is
      just fine to clear it after q->make_request_fn is returned. Especially
      the same bio can't be submitted from another context.
      
      Fixes: cd4a4ae4 ("block: don't use blocking queue entered for recursive bio submits")
      Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Cc: NeilBrown <neilb@suse.com>
      Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      698cef17
  3. 19 Dec, 2018 1 commit
  4. 14 Dec, 2018 1 commit
  5. 10 Dec, 2018 2 commits
  6. 30 Nov, 2018 1 commit
    • Ming Lei's avatar
      block: fix single range discard merge · 2a5cf35c
      Ming Lei authored
      There are actually two kinds of discard merge:
      
      - one is the normal discard merge, just like normal read/write request,
      and call it single-range discard
      
      - another is the multi-range discard, queue_max_discard_segments(rq->q) > 1
      
      For the former case, queue_max_discard_segments(rq->q) is 1, and we
      should handle this kind of discard merge like the normal read/write
      request.
      
      This patch fixes the following kernel panic issue[1], which is caused by
      not removing the single-range discard request from elevator queue.
      
      Guangwu has one raid discard test case, in which this issue is a bit
      easier to trigger, and I verified that this patch can fix the kernel
      panic issue in Guangwu's test case.
      
      [1] kernel panic log from Jens's report
      
       BUG: unable to handle kernel NULL pointer dereference at 0000000000000148
       PGD 0 P4D 0.
       Oops: 0000 [#1] SMP PTI
       CPU: 37 PID: 763 Comm: kworker/37:1H Not tainted \
      4.20.0-rc3-00649-ge64d9a554a91-dirty #14  Hardware name: Wiwynn \
      Leopard-Orv2/Leopard-DDR BW, BIOS LBM08   03/03/2017       Workqueue: kblockd \
      blk_mq_run_work_fn                                            RIP: \
      0010:blk_mq_get_driver_tag+0x81/0x120                                       Code: 24 \
      10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 00 00 00 \
      0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 20 72 37 \
      f6 87 b0 00 00 00 02  RSP: 0018:ffffc90004aabd30 EFLAGS: 00010246                     \
        RAX: 0000000000000003 RBX: ffff888465ea1300 RCX: ffffc90004aabde8
       RDX: 00000000ffffffff RSI: ffffc90004aabde8 RDI: 0000000000000000
       RBP: 0000000000000000 R08: ffff888465ea1348 R09: 0000000000000000
       R10: 0000000000001000 R11: 00000000ffffffff R12: ffff888465ea1300
       R13: 0000000000000000 R14: ffff888465ea1348 R15: ffff888465d10000
       FS:  0000000000000000(0000) GS:ffff88846f9c0000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       CR2: 0000000000000148 CR3: 000000000220a003 CR4: 00000000003606e0
       DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
       Call Trace:
        blk_mq_dispatch_rq_list+0xec/0x480
        ? elv_rb_del+0x11/0x30
        blk_mq_do_dispatch_sched+0x6e/0xf0
        blk_mq_sched_dispatch_requests+0xfa/0x170
        __blk_mq_run_hw_queue+0x5f/0xe0
        process_one_work+0x154/0x350
        worker_thread+0x46/0x3c0
        kthread+0xf5/0x130
        ? process_one_work+0x350/0x350
        ? kthread_destroy_worker+0x50/0x50
        ret_from_fork+0x1f/0x30
       Modules linked in: sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel \
      kvm switchtec irqbypass iTCO_wdt iTCO_vendor_support efivars cdc_ether usbnet mii \
      cdc_acm i2c_i801 lpc_ich mfd_core ipmi_si ipmi_devintf ipmi_msghandler acpi_cpufreq \
      button sch_fq_codel nfsd nfs_acl lockd grace auth_rpcgss oid_registry sunrpc nvme \
      nvme_core fuse sg loop efivarfs autofs4  CR2: 0000000000000148                        \
      
       ---[ end trace 340a1fb996df1b9b ]---
       RIP: 0010:blk_mq_get_driver_tag+0x81/0x120
       Code: 24 10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 \
      00 00 00 0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 \
      20 72 37 f6 87 b0 00 00 00 02
      
      Fixes: 445251d0 ("blk-mq: fix discard merge with scheduler attached")
      Reported-by: default avatarJens Axboe <axboe@kernel.dk>
      Cc: Guangwu Zhang <guazhang@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
      Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      2a5cf35c
  7. 20 Nov, 2018 1 commit
  8. 15 Nov, 2018 1 commit
  9. 09 Nov, 2018 1 commit
  10. 07 Nov, 2018 6 commits
  11. 29 Oct, 2018 1 commit
  12. 24 Sep, 2018 3 commits
  13. 03 Jun, 2018 1 commit
    • Jens Axboe's avatar
      block: don't use blocking queue entered for recursive bio submits · cd4a4ae4
      Jens Axboe authored
      If we end up splitting a bio and the queue goes away between
      the initial submission and the later split submission, then we
      can block forever in blk_queue_enter() waiting for the reference
      to drop to zero. This will never happen, since we already hold
      a reference.
      
      Mark a split bio as already having entered the queue, so we can
      just use the live non-blocking queue enter variant.
      
      Thanks to Tetsuo Handa for the analysis.
      
      Reported-by: syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      cd4a4ae4
  14. 30 May, 2018 1 commit
  15. 09 May, 2018 1 commit
    • Omar Sandoval's avatar
      block: consolidate struct request timestamp fields · 522a7775
      Omar Sandoval authored
      Currently, struct request has four timestamp fields:
      
      - A start time, set at get_request time, in jiffies, used for iostats
      - An I/O start time, set at start_request time, in ktime nanoseconds,
        used for blk-stats (i.e., wbt, kyber, hybrid polling)
      - Another start time and another I/O start time, used for cfq and bfq
      
      These can all be consolidated into one start time and one I/O start
      time, both in ktime nanoseconds, shaving off up to 16 bytes from struct
      request depending on the kernel config.
      Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      522a7775
  16. 01 Feb, 2018 1 commit
    • Jens Axboe's avatar
      blk-mq: fix discard merge with scheduler attached · 445251d0
      Jens Axboe authored
      I ran into an issue on my laptop that triggered a bug on the
      discard path:
      
      WARNING: CPU: 2 PID: 207 at drivers/nvme/host/core.c:527 nvme_setup_cmd+0x3d3/0x430
       Modules linked in: rfcomm fuse ctr ccm bnep arc4 binfmt_misc snd_hda_codec_hdmi nls_iso8859_1 nls_cp437 vfat snd_hda_codec_conexant fat snd_hda_codec_generic iwlmvm snd_hda_intel snd_hda_codec snd_hwdep mac80211 snd_hda_core snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq x86_pkg_temp_thermal intel_powerclamp kvm_intel uvcvideo iwlwifi btusb snd_seq_device videobuf2_vmalloc btintel videobuf2_memops kvm snd_timer videobuf2_v4l2 bluetooth irqbypass videobuf2_core aesni_intel aes_x86_64 crypto_simd cryptd snd glue_helper videodev cfg80211 ecdh_generic soundcore hid_generic usbhid hid i915 psmouse e1000e ptp pps_core xhci_pci xhci_hcd intel_gtt
       CPU: 2 PID: 207 Comm: jbd2/nvme0n1p7- Tainted: G     U           4.15.0+ #176
       Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET59W (1.33 ) 12/19/2017
       RIP: 0010:nvme_setup_cmd+0x3d3/0x430
       RSP: 0018:ffff880423e9f838 EFLAGS: 00010217
       RAX: 0000000000000000 RBX: ffff880423e9f8c8 RCX: 0000000000010000
       RDX: ffff88022b200010 RSI: 0000000000000002 RDI: 00000000327f0000
       RBP: ffff880421251400 R08: ffff88022b200000 R09: 0000000000000009
       R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000ffff
       R13: ffff88042341e280 R14: 000000000000ffff R15: ffff880421251440
       FS:  0000000000000000(0000) GS:ffff880441500000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       CR2: 000055b684795030 CR3: 0000000002e09006 CR4: 00000000001606e0
       DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
       Call Trace:
        nvme_queue_rq+0x40/0xa00
        ? __sbitmap_queue_get+0x24/0x90
        ? blk_mq_get_tag+0xa3/0x250
        ? wait_woken+0x80/0x80
        ? blk_mq_get_driver_tag+0x97/0xf0
        blk_mq_dispatch_rq_list+0x7b/0x4a0
        ? deadline_remove_request+0x49/0xb0
        blk_mq_do_dispatch_sched+0x4f/0xc0
        blk_mq_sched_dispatch_requests+0x106/0x170
        __blk_mq_run_hw_queue+0x53/0xa0
        __blk_mq_delay_run_hw_queue+0x83/0xa0
        blk_mq_run_hw_queue+0x6c/0xd0
        blk_mq_sched_insert_request+0x96/0x140
        __blk_mq_try_issue_directly+0x3d/0x190
        blk_mq_try_issue_directly+0x30/0x70
        blk_mq_make_request+0x1a4/0x6a0
        generic_make_request+0xfd/0x2f0
        ? submit_bio+0x5c/0x110
        submit_bio+0x5c/0x110
        ? __blkdev_issue_discard+0x152/0x200
        submit_bio_wait+0x43/0x60
        ext4_process_freed_data+0x1cd/0x440
        ? account_page_dirtied+0xe2/0x1a0
        ext4_journal_commit_callback+0x4a/0xc0
        jbd2_journal_commit_transaction+0x17e2/0x19e0
        ? kjournald2+0xb0/0x250
        kjournald2+0xb0/0x250
        ? wait_woken+0x80/0x80
        ? commit_timeout+0x10/0x10
        kthread+0x111/0x130
        ? kthread_create_worker_on_cpu+0x50/0x50
        ? do_group_exit+0x3a/0xa0
        ret_from_fork+0x1f/0x30
       Code: 73 89 c1 83 ce 10 c1 e1 10 09 ca 83 f8 04 0f 87 0f ff ff ff 8b 4d 20 48 8b 7d 00 c1 e9 09 48 01 8c c7 00 08 00 00 e9 f8 fe ff ff <0f> ff 4c 89 c7 41 bc 0a 00 00 00 e8 0d 78 d6 ff e9 a1 fc ff ff
       ---[ end trace 50d361cc444506c8 ]---
       print_req_error: I/O error, dev nvme0n1, sector 847167488
      
      Decoding the assembly, the request claims to have 0xffff segments,
      while nvme counts two. This turns out to be because we don't check
      for a data carrying request on the mq scheduler path, and since
      blk_phys_contig_segment() returns true for a non-data request,
      we decrement the initial segment count of 0 and end up with
      0xffff in the unsigned short.
      
      There are a few issues here:
      
      1) We should initialize the segment count for a discard to 1.
      2) The discard merging is currently using the data limits for
         segments and sectors.
      
      Fix this up by having attempt_merge() correctly identify the
      request, and by initializing the segment count correctly
      for discards.
      
      This can only be triggered with mq-deadline on discard capable
      devices right now, which isn't a common configuration.
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      445251d0
  17. 10 Jan, 2018 1 commit
  18. 06 Jan, 2018 3 commits
  19. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  20. 23 Aug, 2017 1 commit
    • Christoph Hellwig's avatar
      block: replace bi_bdev with a gendisk pointer and partitions index · 74d46992
      Christoph Hellwig authored
      This way we don't need a block_device structure to submit I/O.  The
      block_device has different life time rules from the gendisk and
      request_queue and is usually only available when the block device node
      is open.  Other callers need to explicitly create one (e.g. the lightnvm
      passthrough code, or the new nvme multipathing code).
      
      For the actual I/O path all that we need is the gendisk, which exists
      once per block device.  But given that the block layer also does
      partition remapping we additionally need a partition index, which is
      used for said remapping in generic_make_request.
      
      Note that all the block drivers generally want request_queue or
      sometimes the gendisk, so this removes a layer of indirection all
      over the stack.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      74d46992
  21. 09 Aug, 2017 1 commit
  22. 27 Jun, 2017 1 commit
  23. 21 Jun, 2017 1 commit
  24. 18 Jun, 2017 4 commits
  25. 08 Apr, 2017 1 commit
  26. 08 Feb, 2017 2 commits