Hello. May be better call subject something like: "Shortest way to ufs write support", but current subject give more chances to recieve answer. First of all I try explain the current problem: UFS as other block file systems has notition of "block", but further to "block" notion it has "fragment" concept. "fragment" used for preventing waste of space. Usually fragment==block/8, and if "the rest of file" doesn't occupy the whole block, it occupy several fragments. If file grows, at some point "the rest of file" will be occupy 8 fragments. And HERE IS PROBLEM, we should allocate block and move 8 fragments to it. On *BSD/Solaris it is simple: they read analog of buffer_head and change analog of b_blocknr and that's all. The current code of fs/ufs/balloc.c does the same: ---------------------- sb_bread bh->b_blocknr = mark_buffer_dirty (bh) brelse (bh) -------------------------- I suppose you guess: it doesn't work, latter when you do sb_getblk(old_blocknr) it give to us the same block and after that kernel hang up. Hence question: what would be the proper solution in this situation? Is it possible in current VFS change b_blocknr? - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
