[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>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 7b2c8f4f6a6f..629e7abdd840 100644
--- 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);