From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 98ED86B0261 for ; Thu, 15 Dec 2016 18:40:43 -0500 (EST) Received: by mail-pg0-f70.google.com with SMTP id y71so142778650pgd.0 for ; Thu, 15 Dec 2016 15:40:43 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id y3si4493976pgo.229.2016.12.15.15.40.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Dec 2016 15:40:42 -0800 (PST) Subject: [PATCH v4 1/3] dax: masking off __GFP_FS in fs DAX handlers From: Dave Jiang Date: Thu, 15 Dec 2016 16:40:41 -0700 Message-ID: <148184524161.184728.14005697153880489871.stgit@djiang5-desk3.ch.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: 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 The caller into dax needs to clear __GFP_FS mask bit since it's responsible for acquiring locks / transactions that blocks __GFP_FS allocation. The caller will restore the original mask when dax function returns. Signed-off-by: Dave Jiang Reviewed-by: Ross Zwisler Reviewed-by: Jan Kara --- 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; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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