ext4: fix fsx truncate failure
While running extended fsx tests to verify the first
two patches, a similar bug was also found in the
truncate operation.
This bug happens because the truncate routine only zeros
the unblock aligned portion of the last page. This means
that the block aligned portions of the page appearing after
i_size are left unzeroed, and the buffer heads still mapped.
This bug is corrected by using ext4_discard_partial_page_buffers
in the truncate routine to zero the partial page and unmap
the buffer headers.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 2c5216a..ba7bd5a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3653,6 +3653,7 @@
struct super_block *sb = inode->i_sb;
ext4_lblk_t last_block;
handle_t *handle;
+ loff_t page_len;
int err = 0;
/*
@@ -3669,8 +3670,16 @@
if (IS_ERR(handle))
return;
- if (inode->i_size & (sb->s_blocksize - 1))
- ext4_block_truncate_page(handle, mapping, inode->i_size);
+ if (inode->i_size % PAGE_CACHE_SIZE != 0) {
+ page_len = PAGE_CACHE_SIZE -
+ (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+ err = ext4_discard_partial_page_buffers(handle,
+ mapping, inode->i_size, page_len, 0);
+
+ if (err)
+ goto out_stop;
+ }
if (ext4_orphan_add(handle, inode))
goto out_stop;