From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: [PATCH 4/7] dax: Remove dead zeroing code from fault handlers Date: Wed, 11 May 2016 11:58:50 +0200 Message-ID: <1462960733-29634-5-git-send-email-jack@suse.cz> References: <1462960733-29634-1-git-send-email-jack@suse.cz> Cc: Ted Tso , linux-ext4@vger.kernel.org, Vishal Verma , Ross Zwisler , Dan Williams , linux-fsdevel@vger.kernel.org, Jan Kara To: linux-nvdimm@lists.01.org Return-path: Received: from mx2.suse.de ([195.135.220.15]:43899 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751333AbcEKJ7W (ORCPT ); Wed, 11 May 2016 05:59:22 -0400 In-Reply-To: <1462960733-29634-1-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: Now that all filesystems zero out blocks allocated for a fault handler, we can just remove the zeroing from the handler itself. Also add checks that no filesystem returns to us unwritten or new buffer. Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara --- fs/dax.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index c5ccf745d279..ccb8bc399d78 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -587,11 +587,6 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, error = PTR_ERR(dax.addr); goto out; } - - if (buffer_unwritten(bh) || buffer_new(bh)) { - clear_pmem(dax.addr, PAGE_SIZE); - wmb_pmem(); - } dax_unmap_atomic(bdev, &dax); error = dax_radix_entry(mapping, vmf->pgoff, dax.sector, false, @@ -670,7 +665,7 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, if (error) goto unlock_page; - if (!buffer_mapped(&bh) && !buffer_unwritten(&bh) && !vmf->cow_page) { + if (!buffer_mapped(&bh) && !vmf->cow_page) { if (vmf->flags & FAULT_FLAG_WRITE) { error = get_block(inode, block, &bh, 1); count_vm_event(PGMAJFAULT); @@ -722,7 +717,7 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, } /* Filesystem should not return unwritten buffers to us! */ - WARN_ON_ONCE(buffer_unwritten(&bh)); + WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh)); error = dax_insert_mapping(inode, &bh, vma, vmf); out: @@ -854,7 +849,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, if (get_block(inode, block, &bh, 1) != 0) return VM_FAULT_SIGBUS; alloc = true; - WARN_ON_ONCE(buffer_unwritten(&bh)); + WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh)); } bdev = bh.b_bdev; @@ -953,14 +948,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, dax_pmd_dbg(&bh, address, "pfn not in memmap"); goto fallback; }