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
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