[PATCH 3.2 38/79] ocfs2: fix issue that ocfs2_setattr() does not deal with new_i_size==i_size

Ben Hutchings
2018-02-11T04:20:06Z

From: Younger Liu <younger.liu@huawei.com>

commit d62e74be1270c89fbaf7aada8218bfdf62d00a58 upstream.

The issue scenario is as following:

- Create a small file and fallocate a large disk space for a file with
FALLOC_FL_KEEP_SIZE option.

- ftruncate the file back to the original size again. but the disk free
space is not changed back. This is a real bug that be fixed in this
patch.

In order to solve the issue above, we modified ocfs2_setattr(), if
attr->ia_size != i_size_read(inode), It calls ocfs2_truncate_file(), and
truncate disk space to attr->ia_size.

Signed-off-by: Younger Liu <younger.liu@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Tested-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Reviewed-by: Jensen <shencanquan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/ocfs2/alloc.c | 2 +-
fs/ocfs2/file.c | 9 ++-------
2 files changed, 3 insertions(+), 8 deletions(-)

--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -7127,7 +7127,7 @@ int ocfs2_truncate_inline(struct inode *
if (end > i_size_read(inode))
end = i_size_read(inode);

- BUG_ON(start >= end);
+ BUG_ON(start > end);

if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -474,11 +474,6 @@ static int ocfs2_truncate_file(struct in
goto bail;
}

- /* lets handle the simple truncate cases before doing any more
- * cluster locking. */
- if (new_i_size == le64_to_cpu(fe->i_size))
- goto bail;
-
down_write(&OCFS2_I(inode)->ip_alloc_sem);

ocfs2_resv_discard(&osb->osb_la_resmap,
@@ -1149,14 +1144,14 @@ int ocfs2_setattr(struct dentry *dentry,
goto bail_unlock_rw;
}

- if (size_change && attr->ia_size != i_size_read(inode)) {
+ if (size_change) {
status = inode_newsize_ok(inode, attr->ia_size);
if (status)
goto bail_unlock;

inode_dio_wait(inode);

- if (i_size_read(inode) > attr->ia_size) {
+ if (i_size_read(inode) >= attr->ia_size) {
if (ocfs2_should_order_data(inode)) {
status = ocfs2_begin_ordered_truncate(inode,
attr->ia_size);