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Commit 2b10945c authored by Jan Kara's avatar Jan Kara Committed by Vishal Verma
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dax: Remove dead zeroing code from fault handlers 



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: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
parent 86b0624e

fs/dax.c

+2 −15
Original line number Diff line number Diff line
@@ -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,
@@ -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;

		}



		if (buffer_unwritten(&bh) || buffer_new(&bh)) {

			clear_pmem(dax.addr, PMD_SIZE);

			wmb_pmem();

			count_vm_event(PGMAJFAULT);

			mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);

			result |= VM_FAULT_MAJOR;

		}

		dax_unmap_atomic(bdev, &dax);



		/*