__generic_block_fiemap(): fix for files bigger than 4GB

Because of an integer overflow on start_blk, various kind of wrong results
would be returned by the generic_block_fiemap() handler, such as no
extents when there is a 4GB+ hole at the beginning of the file, or wrong
fe_logical when an extent starts after the first 4GB.

Signed-off-by: Mike Hommey <mh@glandium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Eric Sandeen <sandeen@sgi.com>
Cc: Josef Bacik <jbacik@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 7b17a14396ff792152ae6da49d178355d5a5e7ea..6c751106c2e56c7bc318a0fa5f42f528fb8ac363 100644 (file)
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -254,7 +254,7 @@ int __generic_block_fiemap(struct inode *inode,
                           u64 len, get_block_t *get_block)
 {
        struct buffer_head tmp;
-       unsigned int start_blk;
+       unsigned long long start_blk;
        long long length = 0, map_len = 0;
        u64 logical = 0, phys = 0, size = 0;
        u32 flags = FIEMAP_EXTENT_MERGED;