[PATCH] reiserfs_write_full_page() should not get_block past eof
reiserfs_write_full_page does zero bytes in the file past eof, but it may
call get_block on those buffers as well. On machines where the page size
is larger than the blocksize, this can result in mmaped files incorrectly
growing up to a block boundary during writepage.
The fix is to avoid calling get_block for any blocks that are entirely past
eof
Signed-off-by: Chris Mason <mason@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index ac57305..52f1e21 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2340,6 +2340,7 @@
unsigned long end_index = inode->i_size >> PAGE_CACHE_SHIFT;
int error = 0;
unsigned long block;
+ sector_t last_block;
struct buffer_head *head, *bh;
int partial = 0;
int nr = 0;
@@ -2387,10 +2388,19 @@
}
bh = head;
block = page->index << (PAGE_CACHE_SHIFT - s->s_blocksize_bits);
+ last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
/* first map all the buffers, logging any direct items we find */
do {
- if ((checked || buffer_dirty(bh)) && (!buffer_mapped(bh) ||
- (buffer_mapped(bh)
+ if (block > last_block) {
+ /*
+ * This can happen when the block size is less than
+ * the page size. The corresponding bytes in the page
+ * were zero filled above
+ */
+ clear_buffer_dirty(bh);
+ set_buffer_uptodate(bh);
+ } else if ((checked || buffer_dirty(bh)) &&
+ (!buffer_mapped(bh) || (buffer_mapped(bh)
&& bh->b_blocknr ==
0))) {
/* not mapped yet, or it points to a direct item, search