diff options
| author | Anton Altaparmakov <aia21@cam.ac.uk> | 2007-11-03 07:38:59 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-03 12:27:21 -0700 |
| commit | ebab89909e0dc716282d5e7f6e73a3155fe66d4a (patch) | |
| tree | 8cee9ff6f9e0a08c6f08853e38e563514e92a99e /fs/ntfs | |
| parent | 74521c28e550c4ec265cda14114bd9b908e9de34 (diff) | |
| download | lwn-ebab89909e0dc716282d5e7f6e73a3155fe66d4a.tar.gz lwn-ebab89909e0dc716282d5e7f6e73a3155fe66d4a.zip | |
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 <aia21@cantab.net>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ntfs')
| -rw-r--r-- | fs/ntfs/aops.c | 10 | ||||
| -rw-r--r-- | fs/ntfs/attrib.c | 5 | ||||
| -rw-r--r-- | fs/ntfs/compress.c | 10 |
3 files changed, 20 insertions, 5 deletions
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index cfdc7900d271..ad87cb01299b 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -405,6 +405,15 @@ static int ntfs_readpage(struct file *file, struct page *page) retry_readpage: BUG_ON(!PageLocked(page)); + vi = page->mapping->host; + 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. @@ -413,7 +422,6 @@ retry_readpage: unlock_page(page); return 0; } - vi = page->mapping->host; ni = NTFS_I(vi); /* * Only $DATA attributes can be encrypted and only unnamed $DATA diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 92dabdcf2b80..50d3b0c258e3 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 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++) { |