From efee2b812645d10824bf6cb247789910bcb66881 Mon Sep 17 00:00:00 2001 From: Evgeniy Dushistov Date: Mon, 29 Jan 2007 13:19:56 -0800 Subject: [PATCH] [PATCH] ufs: reallocation fix In blocks reallocation function sometimes does not update some of buffer_head::b_blocknr, which may and cause data damage. Signed-off-by: Evgeniy Dushistov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ufs/balloc.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c index 96ca8453bab6..638f4c585e89 100644 --- a/fs/ufs/balloc.c +++ b/fs/ufs/balloc.c @@ -227,14 +227,14 @@ failed: * We can come here from ufs_writepage or ufs_prepare_write, * locked_page is argument of these functions, so we already lock it. */ -static void ufs_change_blocknr(struct inode *inode, unsigned int baseblk, +static void ufs_change_blocknr(struct inode *inode, unsigned int beg, unsigned int count, unsigned int oldb, unsigned int newb, struct page *locked_page) { - unsigned int blk_per_page = 1 << (PAGE_CACHE_SHIFT - inode->i_blkbits); - struct address_space *mapping = inode->i_mapping; + const unsigned mask = (1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1; + struct address_space * const mapping = inode->i_mapping; pgoff_t index, cur_index; - unsigned int i, j; + unsigned end, pos, j; struct page *page; struct buffer_head *head, *bh; @@ -246,8 +246,8 @@ static void ufs_change_blocknr(struct inode *inode, unsigned int baseblk, cur_index = locked_page->index; - for (i = 0; i < count; i += blk_per_page) { - index = (baseblk+i) >> (PAGE_CACHE_SHIFT - inode->i_blkbits); + for (end = count + beg; beg < end; beg = (beg | mask) + 1) { + index = beg >> (PAGE_CACHE_SHIFT - inode->i_blkbits); if (likely(cur_index != index)) { page = ufs_get_locked_page(mapping, index); @@ -256,21 +256,32 @@ static void ufs_change_blocknr(struct inode *inode, unsigned int baseblk, } else page = locked_page; - j = i; head = page_buffers(page); bh = head; + pos = beg & mask; + for (j = 0; j < pos; ++j) + bh = bh->b_this_page; + j = 0; do { - if (likely(bh->b_blocknr == j + oldb && j < count)) { - unmap_underlying_metadata(bh->b_bdev, - bh->b_blocknr); - bh->b_blocknr = newb + j++; - mark_buffer_dirty(bh); + if (buffer_mapped(bh)) { + pos = bh->b_blocknr - oldb; + if (pos < count) { + UFSD(" change from %llu to %llu\n", + (unsigned long long)pos + oldb, + (unsigned long long)pos + newb); + bh->b_blocknr = newb + pos; + unmap_underlying_metadata(bh->b_bdev, + bh->b_blocknr); + mark_buffer_dirty(bh); + ++j; + } } bh = bh->b_this_page; } while (bh != head); - set_page_dirty(page); + if (j) + set_page_dirty(page); if (likely(cur_index != index)) ufs_put_locked_page(page); @@ -418,14 +429,14 @@ unsigned ufs_new_fragments(struct inode * inode, __fs32 * p, unsigned fragment, } result = ufs_alloc_fragments (inode, cgno, goal, request, err); if (result) { + ufs_clear_frags(inode, result + oldcount, newcount - oldcount, + locked_page != NULL); ufs_change_blocknr(inode, fragment - oldcount, oldcount, tmp, result, locked_page); *p = cpu_to_fs32(sb, result); *err = 0; UFS_I(inode)->i_lastfrag = max_t(u32, UFS_I(inode)->i_lastfrag, fragment + count); - ufs_clear_frags(inode, result + oldcount, newcount - oldcount, - locked_page != NULL); unlock_super(sb); if (newcount < request) ufs_free_fragments (inode, result + newcount, request - newcount); -- 2.34.1