[PATCH] ntfs: kmap_atomic() atomicity fix

The KM_BIO_SRC_IRQ kmap slot requires local irq protection.
Acked-by: NAnton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/ntfs/aops.c

@@ -92,10 +92,12 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 			ofs = 0;
 			if (file_ofs < init_size)
 				ofs = init_size - file_ofs;
+			local_irq_save(flags);
 			kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
 			memset(kaddr + bh_offset(bh) + ofs, 0,
 					bh->b_size - ofs);
 			kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
+			local_irq_restore(flags);
 			flush_dcache_page(page);
 		}
 	} else {
@@ -143,11 +145,13 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 		recs = PAGE_CACHE_SIZE / rec_size;
 		/* Should have been verified before we got here... */
 		BUG_ON(!recs);
+		local_irq_save(flags);
 		kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
 		for (i = 0; i < recs; i++)
 			post_read_mst_fixup((NTFS_RECORD*)(kaddr +
 					i * rec_size), rec_size);
 		kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
+		local_irq_restore(flags);
 		flush_dcache_page(page);
 		if (likely(page_uptodate && !PageError(page)))
 			SetPageUptodate(page);