From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f197.google.com (mail-wj0-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 2CA726B0038 for ; Thu, 15 Dec 2016 08:46:47 -0500 (EST) Received: by mail-wj0-f197.google.com with SMTP id he10so23091142wjc.6 for ; Thu, 15 Dec 2016 05:46:47 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id za3si1531555wjb.172.2016.12.15.05.46.45 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 15 Dec 2016 05:46:45 -0800 (PST) Date: Thu, 15 Dec 2016 14:46:41 +0100 From: Jan Kara Subject: Re: [PATCH v2 1/3] dax: masking off __GFP_FS in fs DAX handlers Message-ID: <20161215134641.GA13811@quack2.suse.cz> References: <148174532372.194339.4875475197715168429.stgit@djiang5-desk3.ch.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <148174532372.194339.4875475197715168429.stgit@djiang5-desk3.ch.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Jiang Cc: akpm@linux-foundation.org, jack@suse.cz, linux-nvdimm@lists.01.org, david@fromorbit.com, hch@lst.de, linux-mm@kvack.org, tytso@mit.edu, ross.zwisler@linux.intel.com, dan.j.williams@intel.com On Wed 14-12-16 12:55:23, Dave Jiang wrote: > The callers into dax needs to clear __GFP_FS since they are responsible > for acquiring locks / transactions that block __GFP_FS allocation. They > will restore the lag when dax function return. ^^^ flags ^^^ returns. Otherwise the patch looks good to me. Feel free to add: Reviewed-by: Jan Kara Honza > > Signed-off-by: Dave Jiang > --- > fs/dax.c | 1 + > fs/ext2/file.c | 9 ++++++++- > fs/ext4/file.c | 10 +++++++++- > fs/xfs/xfs_file.c | 14 +++++++++++++- > 4 files changed, 31 insertions(+), 3 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index d3fe880..6395bc6 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -1380,6 +1380,7 @@ int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, > vmf.pgoff = pgoff; > vmf.flags = flags; > vmf.gfp_mask = mapping_gfp_mask(mapping) | __GFP_IO; > + vmf.gfp_mask &= ~__GFP_FS; > > switch (iomap.type) { > case IOMAP_MAPPED: > diff --git a/fs/ext2/file.c b/fs/ext2/file.c > index b0f2415..8422d5f 100644 > --- a/fs/ext2/file.c > +++ b/fs/ext2/file.c > @@ -92,16 +92,19 @@ static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) > struct inode *inode = file_inode(vma->vm_file); > struct ext2_inode_info *ei = EXT2_I(inode); > int ret; > + gfp_t old_gfp = vmf->gfp_mask; > > if (vmf->flags & FAULT_FLAG_WRITE) { > sb_start_pagefault(inode->i_sb); > file_update_time(vma->vm_file); > } > + vmf->gfp_mask &= ~__GFP_FS; > down_read(&ei->dax_sem); > > ret = dax_iomap_fault(vma, vmf, &ext2_iomap_ops); > > up_read(&ei->dax_sem); > + vmf->gfp_mask = old_gfp; > if (vmf->flags & FAULT_FLAG_WRITE) > sb_end_pagefault(inode->i_sb); > return ret; > @@ -114,6 +117,7 @@ static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma, > struct ext2_inode_info *ei = EXT2_I(inode); > loff_t size; > int ret; > + gfp_t old_gfp = vmf->gfp_mask; > > sb_start_pagefault(inode->i_sb); > file_update_time(vma->vm_file); > @@ -123,8 +127,11 @@ static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma, > size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > if (vmf->pgoff >= size) > ret = VM_FAULT_SIGBUS; > - else > + else { > + vmf->gfp_mask &= ~__GFP_FS; > ret = dax_pfn_mkwrite(vma, vmf); > + vmf->gfp_mask = old_gfp; > + } > > up_read(&ei->dax_sem); > sb_end_pagefault(inode->i_sb); > diff --git a/fs/ext4/file.c b/fs/ext4/file.c > index d663d3d..a3f2bf0 100644 > --- a/fs/ext4/file.c > +++ b/fs/ext4/file.c > @@ -261,14 +261,17 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) > struct inode *inode = file_inode(vma->vm_file); > struct super_block *sb = inode->i_sb; > bool write = vmf->flags & FAULT_FLAG_WRITE; > + gfp_t old_gfp = vmf->gfp_mask; > > if (write) { > sb_start_pagefault(sb); > file_update_time(vma->vm_file); > } > + vmf->gfp_mask &= ~__GFP_FS; > down_read(&EXT4_I(inode)->i_mmap_sem); > result = dax_iomap_fault(vma, vmf, &ext4_iomap_ops); > up_read(&EXT4_I(inode)->i_mmap_sem); > + vmf->gfp_mask = old_gfp; > if (write) > sb_end_pagefault(sb); > > @@ -320,8 +323,13 @@ static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma, > size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > if (vmf->pgoff >= size) > ret = VM_FAULT_SIGBUS; > - else > + else { > + gfp_t old_gfp = vmf->gfp_mask; > + > + vmf->gfp_mask &= ~__GFP_FS; > ret = dax_pfn_mkwrite(vma, vmf); > + vmf->gfp_mask = old_gfp; > + } > up_read(&EXT4_I(inode)->i_mmap_sem); > sb_end_pagefault(sb); > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index d818c16..52202b4 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -1474,7 +1474,11 @@ xfs_filemap_page_mkwrite( > xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); > > if (IS_DAX(inode)) { > + gfp_t old_gfp = vmf->gfp_mask; > + > + vmf->gfp_mask &= ~__GFP_FS; > ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops); > + vmf->gfp_mask = old_gfp; > } else { > ret = iomap_page_mkwrite(vma, vmf, &xfs_iomap_ops); > ret = block_page_mkwrite_return(ret); > @@ -1502,13 +1506,16 @@ xfs_filemap_fault( > > xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); > if (IS_DAX(inode)) { > + gfp_t old_gfp = vmf->gfp_mask; > /* > * we do not want to trigger unwritten extent conversion on read > * faults - that is unnecessary overhead and would also require > * changes to xfs_get_blocks_direct() to map unwritten extent > * ioend for conversion on read-only mappings. > */ > + vmf->gfp_mask &= ~__GFP_FS; > ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops); > + vmf->gfp_mask = old_gfp; > } else > ret = filemap_fault(vma, vmf); > xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); > @@ -1581,8 +1588,13 @@ xfs_filemap_pfn_mkwrite( > size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > if (vmf->pgoff >= size) > ret = VM_FAULT_SIGBUS; > - else if (IS_DAX(inode)) > + else if (IS_DAX(inode)) { > + gfp_t old_gfp = vmf->gfp_mask; > + > + vmf->gfp_mask &= ~__GFP_FS; > ret = dax_pfn_mkwrite(vma, vmf); > + vmf->gfp_mask = old_gfp; > + } > xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); > sb_end_pagefault(inode->i_sb); > return ret; > -- Jan Kara SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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