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>
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index cfdc790..ad87cb0 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -405,6 +405,15 @@
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 @@
unlock_page(page);
return 0;
}
- vi = page->mapping->host;
ni = NTFS_I(vi);
/*
* Only $DATA attributes can be encrypted and only unnamed $DATA