fs/ext2: Replace kmap_atomic() with kmap_local_page()

kmap_atomic() is deprecated in favor of kmap_local_page(). Therefore,
replace kmap_atomic() with kmap_local_page().

kmap_atomic() is implemented like a kmap_local_page() which also disables
page-faults and preemption (the latter only for !PREEMPT_RT kernels).

However, the code within the mapping and un-mapping in ext2_make_empty()
does not depend on the above-mentioned side effects.

Therefore, a mere replacement of the old API with the new one is all it
is required (i.e., there is no need to explicitly add any calls to
pagefault_disable() and/or preempt_disable()).
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20221231174205.8492-1-fmdefrancesco@gmail.com>

fs/ext2/dir.c

@@ -646,7 +646,7 @@ int ext2_make_empty(struct inode *inode, struct inode *parent)
 		unlock_page(page);
 		goto fail;
 	}
-	kaddr = kmap_atomic(page);
+	kaddr = kmap_local_page(page);
 	memset(kaddr, 0, chunk_size);
 	de = (struct ext2_dir_entry_2 *)kaddr;
 	de->name_len = 1;
@@ -661,7 +661,7 @@ int ext2_make_empty(struct inode *inode, struct inode *parent)
 	de->inode = cpu_to_le32(parent->i_ino);
 	memcpy (de->name, "..\0", 4);
 	ext2_set_de_type (de, inode);
-	kunmap_atomic(kaddr);
+	kunmap_local(kaddr);
 	ext2_commit_chunk(page, 0, chunk_size);
 	err = ext2_handle_dirsync(inode);
 fail: