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82 struct buffer_head *page_bh, *head; 83 int block = 0; 84 85 head = folio_buffers(folio); 86 if (!head) { 87 /* 88 * don't make any buffers if there is only one buffer on 89 * the folio and the folio just needs to be set up to date 90 */ 91 if (inode->i_blkbits == PAGE_SHIFT && 92 buffer_uptodate(bh)) { 93 folio_mark_uptodate(folio); 94 return; 95 } 96 create_empty_buffers(&folio->page, i_blocksize(inode), 0); 97 } Originally there was a "head = page_buffers(page);" here but now head is left as NULL. 98 99 page_bh = head; 100 do { 101 if (block == page_block) { --> 102 page_bh->b_state = bh->b_state; 103 page_bh->b_bdev = bh->b_bdev; 104 page_bh->b_blocknr = bh->b_blocknr; 105 break; 106 } 107 page_bh = page_bh->b_this_page; ^^^^^^^^^ Which will crash. 108 block++; 109 } while (page_bh != head); 110 } regards, dan carpenter