[PATCH] ntfs: kmap_atomic() atomicity fix

The KM_BIO_SRC_IRQ kmap slot requires local irq protection.

Acked-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 7b2c8f4..629e7ab 100644 (file)
--- a/fs/ntfs/aops.c
+++ b/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);