Re: [PATCH v2] mm: implement write-behind policy for sequential file writes

From: kbuild test robot
Date: Sun Sep 22 2019 - 03:41:49 EST


Hi Konstantin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[cannot apply to v5.3 next-20190919]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Konstantin-Khlebnikov/mm-implement-write-behind-policy-for-sequential-file-writes/20190920-155606
reproduce: make htmldocs
:::::: branch date: 8 hours ago
:::::: commit date: 8 hours ago

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c:1: warning: no structured comments found
drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:1: warning: no structured comments found
drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c:1: warning: 'pp_dpm_sclk pp_dpm_mclk pp_dpm_pcie' not found
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:132: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source @atomic_obj
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:238: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source gpu_info FW provided soc bounding box struct or 0 if not
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'atomic_obj' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'backlight_link' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'backlight_caps' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'freesync_module' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'fw_dmcu' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'dmcu_fw_version' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h:243: warning: Function parameter or member 'soc_bounding_box' not described in 'amdgpu_display_manager'
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:1: warning: 'register_hpd_handlers' not found
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:1: warning: 'dm_crtc_high_irq' not found
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:1: warning: 'dm_pflip_high_irq' not found
include/linux/spi/spi.h:190: warning: Function parameter or member 'driver_override' not described in 'spi_device'
drivers/gpio/gpiolib-of.c:92: warning: Excess function parameter 'dev' description in 'of_gpio_need_valid_mask'
include/linux/i2c.h:337: warning: Function parameter or member 'init_irq' not described in 'i2c_client'
include/linux/regulator/machine.h:196: warning: Function parameter or member 'max_uV_step' not described in 'regulation_constraints'
include/linux/regulator/driver.h:223: warning: Function parameter or member 'resume' not described in 'regulator_ops'
fs/fs-writeback.c:913: warning: Excess function parameter 'nr_pages' description in 'cgroup_writeback_by_id'
fs/direct-io.c:258: warning: Excess function parameter 'offset' description in 'dio_complete'
fs/libfs.c:496: warning: Excess function parameter 'available' description in 'simple_write_end'
fs/posix_acl.c:647: warning: Function parameter or member 'inode' not described in 'posix_acl_update_mode'
fs/posix_acl.c:647: warning: Function parameter or member 'mode_p' not described in 'posix_acl_update_mode'
fs/posix_acl.c:647: warning: Function parameter or member 'acl' not described in 'posix_acl_update_mode'
drivers/usb/typec/bus.c:1: warning: 'typec_altmode_unregister_driver' not found
drivers/usb/typec/bus.c:1: warning: 'typec_altmode_register_driver' not found
drivers/usb/typec/class.c:1: warning: 'typec_altmode_register_notifier' not found
drivers/usb/typec/class.c:1: warning: 'typec_altmode_unregister_notifier' not found
kernel/dma/coherent.c:1: warning: no structured comments found
include/linux/input/sparse-keymap.h:43: warning: Function parameter or member 'sw' not described in 'key_entry'
include/linux/skbuff.h:888: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'list' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'skb_mstamp_ns' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member '__pkt_vlan_present_offset' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'vlan_present' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
include/linux/skbuff.h:888: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
include/net/sock.h:233: warning: Function parameter or member 'skc_addrpair' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_portpair' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_ipv6only' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_net_refcnt' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_v6_daddr' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_v6_rcv_saddr' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_cookie' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_listener' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_tw_dr' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_rcv_wnd' not described in 'sock_common'
include/net/sock.h:233: warning: Function parameter or member 'skc_tw_rcv_nxt' not described in 'sock_common'
include/net/sock.h:515: warning: Function parameter or member 'sk_rx_skb_cache' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_wq_raw' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'tcp_rtx_queue' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_tx_skb_cache' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_route_forced_caps' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_txtime_report_errors' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_validate_xmit_skb' not described in 'sock'
include/net/sock.h:515: warning: Function parameter or member 'sk_bpf_storage' not described in 'sock'
include/net/sock.h:2439: warning: Function parameter or member 'tcp_rx_skb_cache_key' not described in 'DECLARE_STATIC_KEY_FALSE'
include/net/sock.h:2439: warning: Excess function parameter 'sk' description in 'DECLARE_STATIC_KEY_FALSE'
include/net/sock.h:2439: warning: Excess function parameter 'skb' description in 'DECLARE_STATIC_KEY_FALSE'
include/linux/netdevice.h:2053: warning: Function parameter or member 'gso_partial_features' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'l3mdev_ops' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'xfrmdev_ops' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'tlsdev_ops' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'name_assign_type' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'ieee802154_ptr' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'mpls_ptr' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'xdp_prog' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'gro_flush_timeout' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'nf_hooks_ingress' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member '____cacheline_aligned_in_smp' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'qdisc_hash' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'xps_cpus_map' not described in 'net_device'
include/linux/netdevice.h:2053: warning: Function parameter or member 'xps_rxqs_map' not described in 'net_device'
include/linux/phylink.h:56: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising' not described in 'phylink_link_state'
include/linux/phylink.h:56: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(lp_advertising' not described in 'phylink_link_state'
drivers/net/phy/phylink.c:595: warning: Function parameter or member 'config' not described in 'phylink_create'
drivers/net/phy/phylink.c:595: warning: Excess function parameter 'ndev' description in 'phylink_create'
lib/genalloc.c:1: warning: 'gen_pool_add_virt' not found
lib/genalloc.c:1: warning: 'gen_pool_alloc' not found
lib/genalloc.c:1: warning: 'gen_pool_free' not found
lib/genalloc.c:1: warning: 'gen_pool_alloc_algo' not found
include/linux/bitmap.h:341: warning: Function parameter or member 'nbits' not described in 'bitmap_or_equal'
include/linux/rculist.h:374: warning: Excess function parameter 'cond' description in 'list_for_each_entry_rcu'
include/linux/rculist.h:651: warning: Excess function parameter 'cond' description in 'hlist_for_each_entry_rcu'
mm/util.c:1: warning: 'get_user_pages_fast' not found
mm/slab.c:4215: warning: Function parameter or member 'objp' not described in '__ksize'
>> mm/filemap.c:3551: warning: Function parameter or member 'iocb' not described in 'generic_write_behind'
>> mm/filemap.c:3551: warning: Function parameter or member 'count' not described in 'generic_write_behind'
include/drm/drm_modeset_helper_vtables.h:1053: warning: Function parameter or member 'prepare_writeback_job' not described in 'drm_connector_helper_funcs'
include/drm/drm_modeset_helper_vtables.h:1053: warning: Function parameter or member 'cleanup_writeback_job' not described in 'drm_connector_helper_funcs'
include/drm/drm_atomic_state_helper.h:1: warning: no structured comments found
include/drm/drm_gem_shmem_helper.h:87: warning: Function parameter or member 'madv' not described in 'drm_gem_shmem_object'
include/drm/drm_gem_shmem_helper.h:87: warning: Function parameter or member 'madv_list' not described in 'drm_gem_shmem_object'
drivers/gpu/drm/i915/display/intel_dpll_mgr.h:158: warning: Enum value 'DPLL_ID_TGL_MGPLL5' not described in enum 'intel_dpll_id'
drivers/gpu/drm/i915/display/intel_dpll_mgr.h:158: warning: Enum value 'DPLL_ID_TGL_MGPLL6' not described in enum 'intel_dpll_id'
drivers/gpu/drm/i915/display/intel_dpll_mgr.h:158: warning: Excess enum value 'DPLL_ID_TGL_TCPLL6' description in 'intel_dpll_id'
drivers/gpu/drm/i915/display/intel_dpll_mgr.h:158: warning: Excess enum value 'DPLL_ID_TGL_TCPLL5' description in 'intel_dpll_id'
drivers/gpu/drm/i915/display/intel_dpll_mgr.h:342: warning: Function parameter or member 'wakeref' not described in 'intel_shared_dpll'
Error: Cannot open file drivers/gpu/drm/i915/i915_gem_batch_pool.c
Error: Cannot open file drivers/gpu/drm/i915/i915_gem_batch_pool.c
Error: Cannot open file drivers/gpu/drm/i915/i915_gem_batch_pool.c
drivers/gpu/drm/i915/i915_drv.h:1129: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source The OA context specific information.
drivers/gpu/drm/i915/i915_drv.h:1143: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source State of the OA buffer.
drivers/gpu/drm/i915/i915_drv.h:1154: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Locks reads and writes to all head/tail state
drivers/gpu/drm/i915/i915_drv.h:1176: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source One 'aging' tail pointer and one 'aged' tail pointer ready to
drivers/gpu/drm/i915/i915_drv.h:1188: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Index for the aged tail ready to read() data up to.
drivers/gpu/drm/i915/i915_drv.h:1193: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source A monotonic timestamp for when the current aging tail pointer
drivers/gpu/drm/i915/i915_drv.h:1199: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Although we can always read back the head pointer register,
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'pinned_ctx' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'specific_ctx_id' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'specific_ctx_id_mask' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'poll_check_timer' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'poll_wq' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'pollin' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'periodic' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'period_exponent' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1207: warning: Function parameter or member 'oa_buffer' not described in 'i915_perf_stream'
drivers/gpu/drm/i915/i915_drv.h:1129: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source The OA context specific information.
drivers/gpu/drm/i915/i915_drv.h:1143: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source State of the OA buffer.
drivers/gpu/drm/i915/i915_drv.h:1154: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Locks reads and writes to all head/tail state
drivers/gpu/drm/i915/i915_drv.h:1176: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source One 'aging' tail pointer and one 'aged' tail pointer ready to
drivers/gpu/drm/i915/i915_drv.h:1188: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Index for the aged tail ready to read() data up to.
drivers/gpu/drm/i915/i915_drv.h:1193: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source A monotonic timestamp for when the current aging tail pointer
drivers/gpu/drm/i915/i915_drv.h:1199: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Although we can always read back the head pointer register,
drivers/gpu/drm/i915/i915_drv.h:1129: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source The OA context specific information.
drivers/gpu/drm/i915/i915_drv.h:1143: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source State of the OA buffer.
drivers/gpu/drm/i915/i915_drv.h:1154: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Locks reads and writes to all head/tail state
drivers/gpu/drm/i915/i915_drv.h:1176: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source One 'aging' tail pointer and one 'aged' tail pointer ready to
drivers/gpu/drm/i915/i915_drv.h:1188: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Index for the aged tail ready to read() data up to.
drivers/gpu/drm/i915/i915_drv.h:1193: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source A monotonic timestamp for when the current aging tail pointer
drivers/gpu/drm/i915/i915_drv.h:1199: warning: Incorrect use of kernel-doc format: Documentation Makefile include scripts source Although we can always read back the head pointer register,
drivers/gpu/drm/mcde/mcde_drv.c:1: warning: 'ST-Ericsson MCDE DRM Driver' not found
include/net/cfg80211.h:1185: warning: Function parameter or member 'txpwr' not described in 'station_parameters'
include/net/mac80211.h:4056: warning: Function parameter or member 'sta_set_txpwr' not described in 'ieee80211_ops'
include/net/mac80211.h:2018: warning: Function parameter or member 'txpwr' not described in 'ieee80211_sta'
Documentation/admin-guide/perf/imx-ddr.rst:21: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/imx-ddr.rst:34: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/imx-ddr.rst:40: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/imx-ddr.rst:45: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/imx-ddr.rst:52: WARNING: Unexpected indentation.
Documentation/hwmon/inspur-ipsps1.rst:2: WARNING: Title underline too short.

# https://github.com/0day-ci/linux/commit/e0e7df8d5b71bf59ad93fe75e662c929b580d805
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout e0e7df8d5b71bf59ad93fe75e662c929b580d805
vim +3551 mm/filemap.c

e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3534
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3535 /**
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3536 * generic_write_behind() - writeback dirty pages behind current position.
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3537 *
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3538 * This function tracks writing position. If file has enough sequentially
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3539 * written data it starts background writeback and then waits for previous
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3540 * writeback initiated some iterations ago.
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3541 *
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3542 * Write-behind maintains per-file head cursor in file->f_write_behind and
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3543 * two windows around: background writeback before and pending data after.
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3544 *
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3545 * |<-wait-this->| |<-send-this->|<---pending-write-behind--->|
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3546 * |<--async-write-behind--->|<--------previous-data------>|<-new-data->|
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3547 * current head-^ new head-^ file position-^
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3548 */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3549 void generic_write_behind(struct kiocb *iocb, ssize_t count)
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3550 {
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 @3551 struct file *file = iocb->ki_filp;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3552 struct address_space *mapping = file->f_mapping;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3553 struct inode *inode = mapping->host;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3554 struct backing_dev_info *bdi = inode_to_bdi(inode);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3555 unsigned long window = READ_ONCE(bdi->write_behind_pages);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3556 pgoff_t head = file->f_write_behind;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3557 pgoff_t begin = (iocb->ki_pos - count) >> PAGE_SHIFT;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3558 pgoff_t end = iocb->ki_pos >> PAGE_SHIFT;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3559
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3560 /* Skip if write is random, direct, sync or disabled for disk */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3561 if ((file->f_mode & FMODE_RANDOM) || !window ||
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3562 (iocb->ki_flags & (IOCB_DIRECT | IOCB_DSYNC)))
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3563 return;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3564
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3565 /* Skip non-sequential writes in strictly sequential mode. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3566 if (vm_dirty_write_behind < 2 &&
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3567 iocb->ki_pos != i_size_read(inode) &&
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3568 !(iocb->ki_flags & IOCB_APPEND))
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3569 return;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3570
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3571 /* Contigious write and still within window. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3572 if (end - head < window)
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3573 return;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3574
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3575 spin_lock(&file->f_lock);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3576
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3577 /* Re-read under lock. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3578 head = file->f_write_behind;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3579
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3580 /* Non-contiguous, move head position. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3581 if (head > end || begin - head > window) {
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3582 /*
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3583 * Append might happen though multiple files or via new file
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3584 * every time. Align head cursor to cover previous appends.
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3585 */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3586 if (iocb->ki_flags & IOCB_APPEND)
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3587 begin = roundup(begin - min(begin, window - 1),
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3588 bdi->io_pages);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3589
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3590 file->f_write_behind = head = begin;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3591 }
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3592
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3593 /* Still not big enough. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3594 if (end - head < window) {
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3595 spin_unlock(&file->f_lock);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3596 return;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3597 }
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3598
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3599 /* Write excess and try at least max_sectors_kb if possible */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3600 end = head + max(end - head - window, min(end - head, bdi->io_pages));
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3601
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3602 /* Set head for next iteration, everything behind will be written. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3603 file->f_write_behind = end;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3604
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3605 spin_unlock(&file->f_lock);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3606
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3607 /* Start background writeback. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3608 __filemap_fdatawrite_range(mapping,
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3609 (loff_t)head << PAGE_SHIFT,
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3610 ((loff_t)end << PAGE_SHIFT) - 1,
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3611 WB_SYNC_NONE);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3612
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3613 if (head < window)
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3614 return;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3615
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3616 /* Wait for pages falling behind writeback window. */
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3617 head -= window;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3618 end -= window;
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3619 __filemap_fdatawait_range(mapping,
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3620 (loff_t)head << PAGE_SHIFT,
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3621 ((loff_t)end << PAGE_SHIFT) - 1);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3622 }
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3623 EXPORT_SYMBOL(generic_write_behind);
e0e7df8d5b71bf Konstantin Khlebnikov 2019-09-20 3624

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

Attachment: .config.gz
Description: .config.gz