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Commit 1550290b authored by Ross Zwisler's avatar Ross Zwisler Committed by Dave Chinner
Browse files

dax: dax_iomap_fault() needs to call iomap_end() 



Currently iomap_end() doesn't do anything for DAX page faults for both ext2
and XFS.  ext2_iomap_end() just checks for a write underrun, and
xfs_file_iomap_end() checks to see if it needs to finish a delayed
allocation.  However, in the future iomap_end() calls might be needed to
make sure we have balanced allocations, locks, etc.  So, add calls to
iomap_end() with appropriate error handling to dax_iomap_fault().

Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 333ccc97

fs/dax.c

+29 −8
Original line number Diff line number Diff line
@@ -1165,6 +1165,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
	struct iomap iomap = { 0 };

	unsigned flags = 0;

	int error, major = 0;

	int locked_status = 0;

	void *entry;



	/*
@@ -1194,7 +1195,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
		goto unlock_entry;

	if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) {

		error = -EIO;		/* fs corruption? */

		goto unlock_entry;

		goto finish_iomap;

	}



	sector = dax_iomap_sector(&iomap, pos);
@@ -1216,13 +1217,15 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
		}



		if (error)

			goto unlock_entry;

			goto finish_iomap;

		if (!radix_tree_exceptional_entry(entry)) {

			vmf->page = entry;

			return VM_FAULT_LOCKED;

		}

			locked_status = VM_FAULT_LOCKED;

		} else {

			vmf->entry = entry;

		return VM_FAULT_DAX_LOCKED;

			locked_status = VM_FAULT_DAX_LOCKED;

		}

		goto finish_iomap;

	}



	switch (iomap.type) {
@@ -1237,8 +1240,10 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
		break;

	case IOMAP_UNWRITTEN:

	case IOMAP_HOLE:

		if (!(vmf->flags & FAULT_FLAG_WRITE))

			return dax_load_hole(mapping, entry, vmf);

		if (!(vmf->flags & FAULT_FLAG_WRITE)) {

			locked_status = dax_load_hole(mapping, entry, vmf);

			break;

		}

		/*FALLTHRU*/

	default:

		WARN_ON_ONCE(1);
@@ -1246,7 +1251,19 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
		break;

	}



 finish_iomap:

	if (ops->iomap_end) {

		if (error) {

			/* keep previous error */

			ops->iomap_end(inode, pos, PAGE_SIZE, 0, flags,

					&iomap);

		} else {

			error = ops->iomap_end(inode, pos, PAGE_SIZE,

					PAGE_SIZE, flags, &iomap);

		}

	}

 unlock_entry:

	if (!locked_status || error)

		put_locked_mapping_entry(mapping, vmf->pgoff, entry);

 out:

	if (error == -ENOMEM)
@@ -1254,6 +1271,10 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, 
	/* -EBUSY is fine, somebody else faulted on the same PTE */

	if (error < 0 && error != -EBUSY)

		return VM_FAULT_SIGBUS | major;

	if (locked_status) {

		WARN_ON_ONCE(error); /* -EBUSY from ops->iomap_end? */

		return locked_status;

	}

	return VM_FAULT_NOPAGE | major;

}

EXPORT_SYMBOL_GPL(dax_iomap_fault);