From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C89192095B9D8 for ; Thu, 24 Aug 2017 00:15:47 -0700 (PDT) Date: Thu, 24 Aug 2017 09:18:19 +0200 From: Jan Kara Subject: Re: [PATCH 13/13] ext4: Support for synchronous DAX faults Message-ID: <20170824071819.GC20465@quack2.suse.cz> References: <20170817160815.30466-1-jack@suse.cz> <20170817160815.30466-14-jack@suse.cz> <20170823183714.GH13778@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170823183714.GH13778@infradead.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Christoph Hellwig Cc: linux-ext4@vger.kernel.org, Jan Kara , linux-nvdimm@lists.01.org, linux-xfs@vger.kernel.org, Andy Lutomirski , linux-fsdevel@vger.kernel.org, Boaz Harrosh List-ID: On Wed 23-08-17 11:37:14, Christoph Hellwig wrote: > > + pfn_t pfn; > > > > if (write) { > > sb_start_pagefault(sb); > > @@ -287,16 +288,39 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf, > > down_read(&EXT4_I(inode)->i_mmap_sem); > > handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, > > EXT4_DATA_TRANS_BLOCKS(sb)); > > + if (IS_ERR(handle)) { > > + up_read(&EXT4_I(inode)->i_mmap_sem); > > + sb_end_pagefault(sb); > > + return VM_FAULT_SIGBUS; > > + } > > } else { > > down_read(&EXT4_I(inode)->i_mmap_sem); > > } > > - if (!IS_ERR(handle)) > > - result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops, NULL); > > - else > > - result = VM_FAULT_SIGBUS; > > + result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops, &pfn); > > Maybe split the error handling refactor into a simple prep patch to > make this one more readable? OK, will do. > > + /* Write fault but PFN mapped only RO? */ > > + if (result & VM_FAULT_NEEDDSYNC) { > > + int err; > > + loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT; > > + size_t len = 0; > > + > > + if (pe_size == PE_SIZE_PTE) > > + len = PAGE_SIZE; > > +#ifdef CONFIG_FS_DAX_PMD > > + else if (pe_size == PE_SIZE_PMD) > > + len = HPAGE_PMD_SIZE; > > +#endif > > + else > > + WARN_ON_ONCE(1); > > + err = vfs_fsync_range(vmf->vma->vm_file, start, > > + start + len - 1, 1); > > + if (err) > > + result = VM_FAULT_SIGBUS; > > + else > > + result = dax_insert_pfn_mkwrite(vmf, pe_size, > > + pfn); > > + } > > I think this needs to become a helper exported from the DAX code, > way too much magic inside the file system as-is. Good point, there isn't anything fs specific in there. Honza -- Jan Kara SUSE Labs, CR _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm