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: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
diff --git a/fs/dax.c b/fs/dax.c
index 83e7894..ccb8bc3 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -587,11 +587,6 @@
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 @@
}
/* 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 @@
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 @@
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);
/*