[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>
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@ -2340,6 +2340,7 @@ static int reiserfs_write_full_page(struct page *page,
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unsigned long end_index = inode->i_size >> PAGE_CACHE_SHIFT;
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int error = 0;
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unsigned long block;
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sector_t last_block;
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struct buffer_head *head, *bh;
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int partial = 0;
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int nr = 0;
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@ -2387,10 +2388,19 @@ static int reiserfs_write_full_page(struct page *page,
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}
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bh = head;
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block = page->index << (PAGE_CACHE_SHIFT - s->s_blocksize_bits);
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last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
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/* first map all the buffers, logging any direct items we find */
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do {
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if ((checked || buffer_dirty(bh)) && (!buffer_mapped(bh) ||
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(buffer_mapped(bh)
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if (block > last_block) {
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/*
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* This can happen when the block size is less than
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* the page size. The corresponding bytes in the page
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* were zero filled above
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*/
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clear_buffer_dirty(bh);
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set_buffer_uptodate(bh);
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} else if ((checked || buffer_dirty(bh)) &&
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(!buffer_mapped(bh) || (buffer_mapped(bh)
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&& bh->b_blocknr ==
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0))) {
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/* not mapped yet, or it points to a direct item, search
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