watch_queue: Use the bitmap API when applicable

Use bitmap_alloc() to simplify code, improve the semantic and reduce
some open-coded arithmetic in allocator arguments.

Also change a memset(0xff) into an equivalent bitmap_fill() to keep
consistency.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index 4bcd400..5b516eb 100644 (file)
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -220,7 +220,6 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes)
        struct page **pages;
        unsigned long *bitmap;
        unsigned long user_bufs;
-       unsigned int bmsize;
        int ret, i, nr_pages;
 
        if (!wqueue)
@@ -259,13 +258,11 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes)
                pages[i]->index = i * WATCH_QUEUE_NOTES_PER_PAGE;
        }
 
-       bmsize = (nr_notes + BITS_PER_LONG - 1) / BITS_PER_LONG;
-       bmsize *= sizeof(unsigned long);
-       bitmap = kmalloc(bmsize, GFP_KERNEL);
+       bitmap = bitmap_alloc(nr_notes, GFP_KERNEL);
        if (!bitmap)
                goto error_p;
 
-       memset(bitmap, 0xff, bmsize);
+       bitmap_fill(bitmap, nr_notes);
        wqueue->notes = pages;
        wqueue->notes_bitmap = bitmap;
        wqueue->nr_pages = nr_pages;