udf: add assertions

Add a few assertions into udf_discard_prealloc() to check that the file is
sane (mostly helps debugging further patches ;).

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index 0449b2216e716623d38ede18a80f2ee9b33e308f..0e328cdc9a454bdf46926bad9101912bb798fa0b 100644 (file)
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -88,8 +88,9 @@ void udf_discard_prealloc(struct inode * inode)
        {
                etype = netype;
                lbcount += elen;
-               if (lbcount > inode->i_size && lbcount - inode->i_size < inode->i_sb->s_blocksize)
+               if (lbcount > inode->i_size && lbcount - elen < inode->i_size)
                {
+                       WARN_ON(lbcount - inode->i_size >= inode->i_sb->s_blocksize);
                        nelen = elen - (lbcount - inode->i_size);
                        epos.offset -= adsize;
                        extent_trunc(inode, &epos, eloc, etype, elen, nelen);
@@ -119,6 +120,7 @@ void udf_discard_prealloc(struct inode * inode)
        }
        UDF_I_LENEXTENTS(inode) = lbcount;
 
+       WARN_ON(lbcount != inode->i_size);
        brelse(epos.bh);
 }