Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760606AbXKBTWg (ORCPT ); Fri, 2 Nov 2007 15:22:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757673AbXKBTWU (ORCPT ); Fri, 2 Nov 2007 15:22:20 -0400 Received: from ppsw-4.csi.cam.ac.uk ([131.111.8.134]:45493 "EHLO ppsw-4.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757346AbXKBTWS (ORCPT ); Fri, 2 Nov 2007 15:22:18 -0400 X-Cam-SpamDetails: Not scanned X-Cam-AntiVirus: No virus found X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Cc: LKML , ntfs-dev , Neil Brown Message-Id: <1EEFFD17-64E7-41C6-BFED-529A5794EC36@cam.ac.uk> From: Anton Altaparmakov To: Mike Galbraith In-Reply-To: <3BFCE55A-F7E2-4A19-8FD9-F23AF2A29D76@cam.ac.uk> Content-Type: multipart/mixed; boundary=Apple-Mail-1-975769019 Subject: Re: [Linux-NTFS-Dev] 2.6.23 regression: second access of empty ntfs file leads to D state hang Mime-Version: 1.0 (Apple Message framework v912) Date: Fri, 2 Nov 2007 19:22:13 +0000 References: <1193638086.7409.21.camel@Homer.simpson.net> <1193658311.7324.2.camel@Homer.simpson.net> <4E61D235-B8E8-43DF-96A5-B3169E6AB223@cam.ac.uk> <1193668997.7284.2.camel@Homer.simpson.net> <1193671099.7172.0.camel@Homer.simpson.net> <1193731202.7229.9.camel@Homer.simpson.net> <3BFCE55A-F7E2-4A19-8FD9-F23AF2A29D76@cam.ac.uk> X-Mailer: Apple Mail (2.912) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3910 Lines: 124 --Apple-Mail-1-975769019 Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Hi Mike, On 30 Oct 2007, at 09:23, Anton Altaparmakov wrote: > On 30 Oct 2007, at 08:00, Mike Galbraith wrote: >> On Mon, 2007-10-29 at 16:18 +0100, Mike Galbraith wrote: >> Not being very good at walking away from unsolved mysteries, I >> chased it >> down. The problem is that... >> commit[a32ea1e1f925399e0d81ca3f7394a44a6dafa12c] Fix read/truncate >> race >> ...calls ntfs_readpage() for a zero i_size inode, which it isn't >> accustomed to. > > Great, thanks for doing that! > >> Below is the hammer which made my box a happy camper again. > > Yes that will fix it but the complete solution is more involved as > there are three related bugs which explain why you were getting the > hangs after the error... I will make a patch for all of these in > the next few days... Attached is a patch that should fix this and the other related issues I found. Would you be able to test it in your setup? Thanks a lot in advance! Best regards, Anton -- Anton Altaparmakov (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer, http://www.linux-ntfs.org/ --Apple-Mail-1-975769019 Content-Disposition: attachment; filename=ntfs-read-fix.diff Content-Type: application/octet-stream; x-unix-mode=0644; name="ntfs-read-fix.diff" Content-Transfer-Encoding: 7bit diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index cfdc790..4e42d4e 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -405,6 +405,14 @@ static int ntfs_readpage(struct file *file, struct page *page) retry_readpage: BUG_ON(!PageLocked(page)); + i_size = i_size_read(vi); + /* Is the page fully outside i_size? (truncate in progress) */ + if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT)) { + zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0); + ntfs_debug("Read outside i_size - truncated?"); + goto done; + } /* * This can potentially happen because we clear PageUptodate() during * ntfs_writepage() of MstProtected() attributes. diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 92dabdc..50d3b0c 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -179,10 +179,7 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx) * ntfs_mapping_pairs_decompress() fails. */ end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1; - if (!a->data.non_resident.lowest_vcn && end_vcn == 1) - end_vcn = sle64_to_cpu(a->data.non_resident.allocated_size) >> - ni->vol->cluster_size_bits; - if (unlikely(vcn >= end_vcn)) { + if (unlikely(vcn && vcn >= end_vcn)) { err = -ENOENT; goto err_out; } diff --git a/fs/ntfs/compress.c b/fs/ntfs/compress.c index d98daf5..d1619d0 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++) { --Apple-Mail-1-975769019 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit --Apple-Mail-1-975769019-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/