From patchwork Wed Apr 7 13:38:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12188409 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D094AC433B4 for ; Wed, 7 Apr 2021 13:38:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9689461284 for ; Wed, 7 Apr 2021 13:38:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235495AbhDGNiv (ORCPT ); Wed, 7 Apr 2021 09:38:51 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:46698 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1344660AbhDGNis (ORCPT ); Wed, 7 Apr 2021 09:38:48 -0400 IronPort-HdrOrdr: A9a23:pWCfXKh67mioTgRJmmJ+vRZ9aHBQXjoji2hD6mlwRA09T+WzkceykPMHkSLlkTp5YgBFpfmsGomlBUnd+5l8/JULMd6ZMTXOlWO0IOhZg7fK7DHtFib3/OwY9YoIScJDIfLqC1wSt6fHyS2ZN/pl/9Wd6qCvgo7lvhJQZCVncbtp4Qs8KivzKDwUeCB8CZA0FIWR66N8zlLORV0scs+5CnMZNtKzxeHjqZSOW347Li9iwAyPoBft07TiDiWfty10bxp/hZsk7kjJ+jaU2pme X-IronPort-AV: E=Sophos;i="5.82,203,1613404800"; d="scan'208";a="106746628" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 07 Apr 2021 21:38:31 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id 6D9EF4D0B8A2; Wed, 7 Apr 2021 21:38:28 +0800 (CST) Received: from G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 7 Apr 2021 21:38:28 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 7 Apr 2021 21:38:27 +0800 From: Shiyang Ruan To: , , , CC: , , , , , , , , , Ritesh Harjani Subject: [PATCH v2 1/3] fsdax: Factor helpers to simplify dax fault code Date: Wed, 7 Apr 2021 21:38:21 +0800 Message-ID: <20210407133823.828176-2-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> References: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: 6D9EF4D0B8A2.A3947 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The dax page fault code is too long and a bit difficult to read. And it is hard to understand when we trying to add new features. Some of the PTE/PMD codes have similar logic. So, factor them as helper functions to simplify the code. Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Ritesh Harjani --- fs/dax.c | 153 ++++++++++++++++++++++++++++++------------------------- 1 file changed, 84 insertions(+), 69 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index b3d27fdc6775..f843fb8fbbf1 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1244,6 +1244,53 @@ static bool dax_fault_is_synchronous(unsigned long flags, && (iomap->flags & IOMAP_F_DIRTY); } +/* + * If we are doing synchronous page fault and inode needs fsync, we can insert + * PTE/PMD into page tables only after that happens. Skip insertion for now and + * return the pfn so that caller can insert it after fsync is done. + */ +static vm_fault_t dax_fault_synchronous_pfnp(pfn_t *pfnp, pfn_t pfn) +{ + if (WARN_ON_ONCE(!pfnp)) + return VM_FAULT_SIGBUS; + + *pfnp = pfn; + return VM_FAULT_NEEDDSYNC; +} + +static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf, struct iomap *iomap, + loff_t pos) +{ + int error = 0; + vm_fault_t ret; + unsigned long vaddr = vmf->address; + sector_t sector = dax_iomap_sector(iomap, pos); + + switch (iomap->type) { + case IOMAP_HOLE: + case IOMAP_UNWRITTEN: + clear_user_highpage(vmf->cow_page, vaddr); + break; + case IOMAP_MAPPED: + error = copy_cow_page_dax(iomap->bdev, iomap->dax_dev, + sector, vmf->cow_page, vaddr); + break; + default: + WARN_ON_ONCE(1); + error = -EIO; + break; + } + + if (error) + return dax_fault_return(error); + + __SetPageUptodate(vmf->cow_page); + ret = finish_fault(vmf); + if (!ret) + ret = VM_FAULT_DONE_COW; + return ret; +} + static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, int *iomap_errp, const struct iomap_ops *ops) { @@ -1312,30 +1359,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, } if (vmf->cow_page) { - sector_t sector = dax_iomap_sector(&iomap, pos); - - switch (iomap.type) { - case IOMAP_HOLE: - case IOMAP_UNWRITTEN: - clear_user_highpage(vmf->cow_page, vaddr); - break; - case IOMAP_MAPPED: - error = copy_cow_page_dax(iomap.bdev, iomap.dax_dev, - sector, vmf->cow_page, vaddr); - break; - default: - WARN_ON_ONCE(1); - error = -EIO; - break; - } - - if (error) - goto error_finish_iomap; - - __SetPageUptodate(vmf->cow_page); - ret = finish_fault(vmf); - if (!ret) - ret = VM_FAULT_DONE_COW; + ret = dax_fault_cow_page(vmf, &iomap, pos); goto finish_iomap; } @@ -1355,19 +1379,8 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, write && !sync); - /* - * If we are doing synchronous page fault and inode needs fsync, - * we can insert PTE into page tables only after that happens. - * Skip insertion for now and return the pfn so that caller can - * insert it after fsync is done. - */ if (sync) { - if (WARN_ON_ONCE(!pfnp)) { - error = -EIO; - goto error_finish_iomap; - } - *pfnp = pfn; - ret = VM_FAULT_NEEDDSYNC | major; + ret = dax_fault_synchronous_pfnp(pfnp, pfn); goto finish_iomap; } trace_dax_insert_mapping(inode, vmf, entry); @@ -1466,13 +1479,45 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, return VM_FAULT_FALLBACK; } +static bool dax_fault_check_fallback(struct vm_fault *vmf, struct xa_state *xas, + pgoff_t max_pgoff) +{ + unsigned long pmd_addr = vmf->address & PMD_MASK; + bool write = vmf->flags & FAULT_FLAG_WRITE; + + /* + * Make sure that the faulting address's PMD offset (color) matches + * the PMD offset from the start of the file. This is necessary so + * that a PMD range in the page table overlaps exactly with a PMD + * range in the page cache. + */ + if ((vmf->pgoff & PG_PMD_COLOUR) != + ((vmf->address >> PAGE_SHIFT) & PG_PMD_COLOUR)) + return true; + + /* Fall back to PTEs if we're going to COW */ + if (write && !(vmf->vma->vm_flags & VM_SHARED)) + return true; + + /* If the PMD would extend outside the VMA */ + if (pmd_addr < vmf->vma->vm_start) + return true; + if ((pmd_addr + PMD_SIZE) > vmf->vma->vm_end) + return true; + + /* If the PMD would extend beyond the file size */ + if ((xas->xa_index | PG_PMD_COLOUR) >= max_pgoff) + return true; + + return false; +} + static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, const struct iomap_ops *ops) { struct vm_area_struct *vma = vmf->vma; struct address_space *mapping = vma->vm_file->f_mapping; XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, PMD_ORDER); - unsigned long pmd_addr = vmf->address & PMD_MASK; bool write = vmf->flags & FAULT_FLAG_WRITE; bool sync; unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; @@ -1495,33 +1540,12 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); - /* - * Make sure that the faulting address's PMD offset (color) matches - * the PMD offset from the start of the file. This is necessary so - * that a PMD range in the page table overlaps exactly with a PMD - * range in the page cache. - */ - if ((vmf->pgoff & PG_PMD_COLOUR) != - ((vmf->address >> PAGE_SHIFT) & PG_PMD_COLOUR)) - goto fallback; - - /* Fall back to PTEs if we're going to COW */ - if (write && !(vma->vm_flags & VM_SHARED)) - goto fallback; - - /* If the PMD would extend outside the VMA */ - if (pmd_addr < vma->vm_start) - goto fallback; - if ((pmd_addr + PMD_SIZE) > vma->vm_end) - goto fallback; - if (xas.xa_index >= max_pgoff) { result = VM_FAULT_SIGBUS; goto out; } - /* If the PMD would extend beyond the file size */ - if ((xas.xa_index | PG_PMD_COLOUR) >= max_pgoff) + if (dax_fault_check_fallback(vmf, &xas, max_pgoff)) goto fallback; /* @@ -1573,17 +1597,8 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, DAX_PMD, write && !sync); - /* - * If we are doing synchronous page fault and inode needs fsync, - * we can insert PMD into page tables only after that happens. - * Skip insertion for now and return the pfn so that caller can - * insert it after fsync is done. - */ if (sync) { - if (WARN_ON_ONCE(!pfnp)) - goto finish_iomap; - *pfnp = pfn; - result = VM_FAULT_NEEDDSYNC; + result = dax_fault_synchronous_pfnp(pfnp, pfn); goto finish_iomap; } From patchwork Wed Apr 7 13:38:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12188413 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1B0DC433ED for ; Wed, 7 Apr 2021 13:38:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA02B6136A for ; Wed, 7 Apr 2021 13:38:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344828AbhDGNi6 (ORCPT ); Wed, 7 Apr 2021 09:38:58 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:46708 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1344743AbhDGNiz (ORCPT ); Wed, 7 Apr 2021 09:38:55 -0400 IronPort-HdrOrdr: A9a23:p7OVk6v2CUM0Vi0QRqMvF4j97skDltV00zAX/kB9WHVpW+afkN2jm+le6A/shF8qKRUdsP2jGI3Fe3PT8pZp/ZIcVI3OYCDKsHalRbsN0aLMzzHsECX19Kp8+M5bGZRWJ8b3CTFB7PrSxCmdP5IezMKc8Kau7N2uqktFaQ1xcalv40NYJ2+gYy5LbTJLD5Y4C5aQj/Avz1WdUE4KZce2DGRtZZmgm/T3kvvdASIuNloO7QmiqXeS4qfmLh7w5HwjegIK7bA80WWtqWDE2pk= X-IronPort-AV: E=Sophos;i="5.82,203,1613404800"; d="scan'208";a="106746640" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 07 Apr 2021 21:38:43 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 307DC4D0B8A2; Wed, 7 Apr 2021 21:38:41 +0800 (CST) Received: from G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 7 Apr 2021 21:38:35 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 7 Apr 2021 21:38:28 +0800 From: Shiyang Ruan To: , , , CC: , , , , , , , , , Ritesh Harjani Subject: [PATCH v2 2/3] fsdax: Factor helper: dax_fault_actor() Date: Wed, 7 Apr 2021 21:38:22 +0800 Message-ID: <20210407133823.828176-3-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> References: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: 307DC4D0B8A2.A3951 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The core logic in the two dax page fault functions is similar. So, move the logic into a common helper function. Also, to facilitate the addition of new features, such as CoW, switch-case is no longer used to handle different iomap types. Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Ritesh Harjani --- fs/dax.c | 294 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 148 insertions(+), 146 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index f843fb8fbbf1..6dea1fc11b46 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1054,6 +1054,66 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, return ret; } +#ifdef CONFIG_FS_DAX_PMD +static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, + struct iomap *iomap, void **entry) +{ + struct address_space *mapping = vmf->vma->vm_file->f_mapping; + unsigned long pmd_addr = vmf->address & PMD_MASK; + struct vm_area_struct *vma = vmf->vma; + struct inode *inode = mapping->host; + pgtable_t pgtable = NULL; + struct page *zero_page; + spinlock_t *ptl; + pmd_t pmd_entry; + pfn_t pfn; + + zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm); + + if (unlikely(!zero_page)) + goto fallback; + + pfn = page_to_pfn_t(zero_page); + *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, + DAX_PMD | DAX_ZERO_PAGE, false); + + if (arch_needs_pgtable_deposit()) { + pgtable = pte_alloc_one(vma->vm_mm); + if (!pgtable) + return VM_FAULT_OOM; + } + + ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); + if (!pmd_none(*(vmf->pmd))) { + spin_unlock(ptl); + goto fallback; + } + + if (pgtable) { + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); + mm_inc_nr_ptes(vma->vm_mm); + } + pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); + pmd_entry = pmd_mkhuge(pmd_entry); + set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); + spin_unlock(ptl); + trace_dax_pmd_load_hole(inode, vmf, zero_page, *entry); + return VM_FAULT_NOPAGE; + +fallback: + if (pgtable) + pte_free(vma->vm_mm, pgtable); + trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); + return VM_FAULT_FALLBACK; +} +#else +static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, + struct iomap *iomap, void **entry) +{ + return VM_FAULT_FALLBACK; +} +#endif /* CONFIG_FS_DAX_PMD */ + s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap) { sector_t sector = iomap_sector(iomap, pos & PAGE_MASK); @@ -1291,6 +1351,64 @@ static vm_fault_t dax_fault_cow_page(struct vm_fault *vmf, struct iomap *iomap, return ret; } +/** + * dax_fault_actor - Common actor to handle pfn insertion in PTE/PMD fault. + * @vmf: vm fault instance + * @pfnp: pfn to be returned + * @xas: the dax mapping tree of a file + * @entry: an unlocked dax entry to be inserted + * @pmd: distinguish whether it is a pmd fault + * @flags: iomap flags + * @iomap: from iomap_begin() + * @srcmap: from iomap_begin(), not equal to iomap if it is a CoW + */ +static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, + struct xa_state *xas, void **entry, bool pmd, + unsigned int flags, struct iomap *iomap, struct iomap *srcmap) +{ + struct address_space *mapping = vmf->vma->vm_file->f_mapping; + size_t size = pmd ? PMD_SIZE : PAGE_SIZE; + loff_t pos = (loff_t)xas->xa_index << PAGE_SHIFT; + bool write = vmf->flags & FAULT_FLAG_WRITE; + bool sync = dax_fault_is_synchronous(flags, vmf->vma, iomap); + unsigned long entry_flags = pmd ? DAX_PMD : 0; + int err = 0; + pfn_t pfn; + + /* if we are reading UNWRITTEN and HOLE, return a hole. */ + if (!write && + (iomap->type == IOMAP_UNWRITTEN || iomap->type == IOMAP_HOLE)) { + if (!pmd) + return dax_load_hole(xas, mapping, entry, vmf); + else + return dax_pmd_load_hole(xas, vmf, iomap, entry); + } + + if (iomap->type != IOMAP_MAPPED) { + WARN_ON_ONCE(1); + return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS; + } + + err = dax_iomap_pfn(iomap, pos, size, &pfn); + if (err) + return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); + + *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, entry_flags, + write && !sync); + + if (sync) + return dax_fault_synchronous_pfnp(pfnp, pfn); + + /* insert PMD pfn */ + if (pmd) + return vmf_insert_pfn_pmd(vmf, pfn, write); + + /* insert PTE pfn */ + if (write) + return vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn); + return vmf_insert_mixed(vmf->vma, vmf->address, pfn); +} + static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, int *iomap_errp, const struct iomap_ops *ops) { @@ -1298,17 +1416,14 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, struct address_space *mapping = vma->vm_file->f_mapping; XA_STATE(xas, &mapping->i_pages, vmf->pgoff); struct inode *inode = mapping->host; - unsigned long vaddr = vmf->address; loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; struct iomap iomap = { .type = IOMAP_HOLE }; struct iomap srcmap = { .type = IOMAP_HOLE }; unsigned flags = IOMAP_FAULT; int error, major = 0; bool write = vmf->flags & FAULT_FLAG_WRITE; - bool sync; vm_fault_t ret = 0; void *entry; - pfn_t pfn; trace_dax_pte_fault(inode, vmf, ret); /* @@ -1354,8 +1469,8 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto unlock_entry; } if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) { - error = -EIO; /* fs corruption? */ - goto error_finish_iomap; + ret = VM_FAULT_SIGBUS; /* fs corruption? */ + goto finish_iomap; } if (vmf->cow_page) { @@ -1363,49 +1478,19 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto finish_iomap; } - sync = dax_fault_is_synchronous(flags, vma, &iomap); - - switch (iomap.type) { - case IOMAP_MAPPED: - if (iomap.flags & IOMAP_F_NEW) { - count_vm_event(PGMAJFAULT); - count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); - major = VM_FAULT_MAJOR; - } - error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn); - if (error < 0) - goto error_finish_iomap; - - entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, - 0, write && !sync); - - if (sync) { - ret = dax_fault_synchronous_pfnp(pfnp, pfn); - goto finish_iomap; - } - trace_dax_insert_mapping(inode, vmf, entry); - if (write) - ret = vmf_insert_mixed_mkwrite(vma, vaddr, pfn); - else - ret = vmf_insert_mixed(vma, vaddr, pfn); - + ret = dax_fault_actor(vmf, pfnp, &xas, &entry, false, flags, + &iomap, &srcmap); + if (ret == VM_FAULT_SIGBUS) goto finish_iomap; - case IOMAP_UNWRITTEN: - case IOMAP_HOLE: - if (!write) { - ret = dax_load_hole(&xas, mapping, &entry, vmf); - goto finish_iomap; - } - fallthrough; - default: - WARN_ON_ONCE(1); - error = -EIO; - break; + + /* read/write MAPPED, CoW UNWRITTEN */ + if (iomap.flags & IOMAP_F_NEW) { + count_vm_event(PGMAJFAULT); + count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); + major = VM_FAULT_MAJOR; } - error_finish_iomap: - ret = dax_fault_return(error); - finish_iomap: +finish_iomap: if (ops->iomap_end) { int copied = PAGE_SIZE; @@ -1419,66 +1504,14 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, */ ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap); } - unlock_entry: +unlock_entry: dax_unlock_entry(&xas, entry); - out: +out: trace_dax_pte_fault_done(inode, vmf, ret); return ret | major; } #ifdef CONFIG_FS_DAX_PMD -static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, - struct iomap *iomap, void **entry) -{ - struct address_space *mapping = vmf->vma->vm_file->f_mapping; - unsigned long pmd_addr = vmf->address & PMD_MASK; - struct vm_area_struct *vma = vmf->vma; - struct inode *inode = mapping->host; - pgtable_t pgtable = NULL; - struct page *zero_page; - spinlock_t *ptl; - pmd_t pmd_entry; - pfn_t pfn; - - zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm); - - if (unlikely(!zero_page)) - goto fallback; - - pfn = page_to_pfn_t(zero_page); - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, - DAX_PMD | DAX_ZERO_PAGE, false); - - if (arch_needs_pgtable_deposit()) { - pgtable = pte_alloc_one(vma->vm_mm); - if (!pgtable) - return VM_FAULT_OOM; - } - - ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); - if (!pmd_none(*(vmf->pmd))) { - spin_unlock(ptl); - goto fallback; - } - - if (pgtable) { - pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); - mm_inc_nr_ptes(vma->vm_mm); - } - pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); - pmd_entry = pmd_mkhuge(pmd_entry); - set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); - spin_unlock(ptl); - trace_dax_pmd_load_hole(inode, vmf, zero_page, *entry); - return VM_FAULT_NOPAGE; - -fallback: - if (pgtable) - pte_free(vma->vm_mm, pgtable); - trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); - return VM_FAULT_FALLBACK; -} - static bool dax_fault_check_fallback(struct vm_fault *vmf, struct xa_state *xas, pgoff_t max_pgoff) { @@ -1519,17 +1552,15 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, struct address_space *mapping = vma->vm_file->f_mapping; XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, PMD_ORDER); bool write = vmf->flags & FAULT_FLAG_WRITE; - bool sync; - unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; + unsigned int flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; struct inode *inode = mapping->host; - vm_fault_t result = VM_FAULT_FALLBACK; + vm_fault_t ret = VM_FAULT_FALLBACK; struct iomap iomap = { .type = IOMAP_HOLE }; struct iomap srcmap = { .type = IOMAP_HOLE }; pgoff_t max_pgoff; void *entry; loff_t pos; int error; - pfn_t pfn; /* * Check whether offset isn't beyond end of file now. Caller is @@ -1541,7 +1572,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); if (xas.xa_index >= max_pgoff) { - result = VM_FAULT_SIGBUS; + ret = VM_FAULT_SIGBUS; goto out; } @@ -1556,7 +1587,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, */ entry = grab_mapping_entry(&xas, mapping, PMD_ORDER); if (xa_is_internal(entry)) { - result = xa_to_internal(entry); + ret = xa_to_internal(entry); goto fallback; } @@ -1568,7 +1599,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, */ if (!pmd_none(*vmf->pmd) && !pmd_trans_huge(*vmf->pmd) && !pmd_devmap(*vmf->pmd)) { - result = 0; + ret = 0; goto unlock_entry; } @@ -1578,49 +1609,21 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, * to look up our filesystem block. */ pos = (loff_t)xas.xa_index << PAGE_SHIFT; - error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap, - &srcmap); + error = ops->iomap_begin(inode, pos, PMD_SIZE, flags, &iomap, &srcmap); if (error) goto unlock_entry; if (iomap.offset + iomap.length < pos + PMD_SIZE) goto finish_iomap; - sync = dax_fault_is_synchronous(iomap_flags, vma, &iomap); - - switch (iomap.type) { - case IOMAP_MAPPED: - error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn); - if (error < 0) - goto finish_iomap; + ret = dax_fault_actor(vmf, pfnp, &xas, &entry, true, flags, + &iomap, &srcmap); - entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, - DAX_PMD, write && !sync); - - if (sync) { - result = dax_fault_synchronous_pfnp(pfnp, pfn); - goto finish_iomap; - } - - trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry); - result = vmf_insert_pfn_pmd(vmf, pfn, write); - break; - case IOMAP_UNWRITTEN: - case IOMAP_HOLE: - if (WARN_ON_ONCE(write)) - break; - result = dax_pmd_load_hole(&xas, vmf, &iomap, &entry); - break; - default: - WARN_ON_ONCE(1); - break; - } - - finish_iomap: +finish_iomap: if (ops->iomap_end) { int copied = PMD_SIZE; - if (result == VM_FAULT_FALLBACK) + if (ret == VM_FAULT_FALLBACK) copied = 0; /* * The fault is done by now and there's no way back (other @@ -1628,19 +1631,18 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, * Just ignore error from ->iomap_end since we cannot do much * with it. */ - ops->iomap_end(inode, pos, PMD_SIZE, copied, iomap_flags, - &iomap); + ops->iomap_end(inode, pos, PMD_SIZE, copied, flags, &iomap); } - unlock_entry: +unlock_entry: dax_unlock_entry(&xas, entry); - fallback: - if (result == VM_FAULT_FALLBACK) { +fallback: + if (ret == VM_FAULT_FALLBACK) { split_huge_pmd(vma, vmf->pmd, vmf->address); count_vm_event(THP_FAULT_FALLBACK); } out: - trace_dax_pmd_fault_done(inode, vmf, max_pgoff, result); - return result; + trace_dax_pmd_fault_done(inode, vmf, max_pgoff, ret); + return ret; } #else static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, From patchwork Wed Apr 7 13:38:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12188415 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD14AC43461 for ; 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07 Apr 2021 21:38:49 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 8FCE44D0B8A3; Wed, 7 Apr 2021 21:38:47 +0800 (CST) Received: from G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 7 Apr 2021 21:38:41 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 7 Apr 2021 21:38:41 +0800 From: Shiyang Ruan To: , , , CC: , , , , , , , , , Ritesh Harjani Subject: [PATCH v2 3/3] fsdax: Output address in dax_iomap_pfn() and rename it Date: Wed, 7 Apr 2021 21:38:23 +0800 Message-ID: <20210407133823.828176-4-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> References: <20210407133823.828176-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: 8FCE44D0B8A3.A396E X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Add address output in dax_iomap_pfn() in order to perform a memcpy() in CoW case. Since this function both output address and pfn, rename it to dax_iomap_direct_access(). Signed-off-by: Shiyang Ruan Reviewed-by: Christoph Hellwig Reviewed-by: Ritesh Harjani --- fs/dax.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 6dea1fc11b46..8d7e4e2cc0fb 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -998,8 +998,8 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9; } -static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, - pfn_t *pfnp) +static int dax_iomap_direct_access(struct iomap *iomap, loff_t pos, size_t size, + void **kaddr, pfn_t *pfnp) { const sector_t sector = dax_iomap_sector(iomap, pos); pgoff_t pgoff; @@ -1011,11 +1011,13 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, return rc; id = dax_read_lock(); length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size), - NULL, pfnp); + kaddr, pfnp); if (length < 0) { rc = length; goto out; } + if (!pfnp) + goto out_check_addr; rc = -EINVAL; if (PFN_PHYS(length) < size) goto out; @@ -1025,6 +1027,12 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, if (length > 1 && !pfn_t_devmap(*pfnp)) goto out; rc = 0; + +out_check_addr: + if (!kaddr) + goto out; + if (!*kaddr) + rc = -EFAULT; out: dax_read_unlock(id); return rc; @@ -1389,7 +1397,7 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS; } - err = dax_iomap_pfn(iomap, pos, size, &pfn); + err = dax_iomap_direct_access(iomap, pos, size, NULL, &pfn); if (err) return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err);