From ebab89909e0dc716282d5e7f6e73a3155fe66d4a Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Sat, 3 Nov 2007 07:38:59 +0000 Subject: NTFS: Fix read regression. The regression was caused by: commit[a32ea1e1f925399e0d81ca3f7394a44a6dafa12c] Fix read/truncate race This causes ntfs_readpage() to be called for a zero i_size inode, which failed when the file was compressed and non-resident. Thanks a lot to Mike Galbraith for reporting the issue and tracking down the commit that caused the regression. Looking into it I found three bugs which the patch fixes. Signed-off-by: Anton Altaparmakov Tested-by: Mike Galbraith Signed-off-by: Linus Torvalds --- fs/ntfs/compress.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs/ntfs/compress.c') diff --git a/fs/ntfs/compress.c b/fs/ntfs/compress.c index d98daf59e0b6..d1619d05eb23 100644 --- a/fs/ntfs/compress.c +++ b/fs/ntfs/compress.c @@ -561,6 +561,16 @@ int ntfs_read_compressed_block(struct page *page) read_unlock_irqrestore(&ni->size_lock, flags); max_page = ((i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) - offset; + /* Is the page fully outside i_size? (truncate in progress) */ + if (xpage >= max_page) { + kfree(bhs); + kfree(pages); + zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0); + ntfs_debug("Compressed read outside i_size - truncated?"); + SetPageUptodate(page); + unlock_page(page); + return 0; + } if (nr_pages < max_page) max_page = nr_pages; for (i = 0; i < max_page; i++, offset++) { -- cgit v1.2.3-59-g8ed1b