ntfs_end_buffer_async_read() disables interrupts around kmap_atomic().
This is a leftover from the old kmap_atomic() implementation which
relied on fixed mapping slots, so the caller had to make sure that the
same slot could not be reused from an interrupting context.
kmap_atomic() was changed to dynamic slots long ago and commit
1ec9c5ddc17a ("include/linux/highmem.h: remove the second argument of
k[un]map_atomic()") removed the slot assignements, but the callers were
not checked for now redundant interrupt disabling.
Remove the conditional interrupt disable.
Link: http://lkml.kernel.org/r/20180611144913.gln5mklhqcrfsoom@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
                        ofs = 0;
                        if (file_ofs < init_size)
                                ofs = init_size - file_ofs;
-                       local_irq_save(flags);
                        kaddr = kmap_atomic(page);
                        memset(kaddr + bh_offset(bh) + ofs, 0,
                                        bh->b_size - ofs);
                        flush_dcache_page(page);
                        kunmap_atomic(kaddr);
-                       local_irq_restore(flags);
                }
        } else {
                clear_buffer_uptodate(bh);
                recs = PAGE_SIZE / rec_size;
                /* Should have been verified before we got here... */
                BUG_ON(!recs);
-               local_irq_save(flags);
                kaddr = kmap_atomic(page);
                for (i = 0; i < recs; i++)
                        post_read_mst_fixup((NTFS_RECORD*)(kaddr +
                                        i * rec_size), rec_size);
                kunmap_atomic(kaddr);
-               local_irq_restore(flags);
                flush_dcache_page(page);
                if (likely(page_uptodate && !PageError(page)))
                        SetPageUptodate(page);