[PATCH 12/18] Revert "ext4: fix fsx truncate failure"

Lukas Czerner
2013-02-01T10:44:19Z

This reverts commit 189e868fa8fdca702eb9db9d8afc46b5cb9144c9.

This commit reintroduces the use of ext4_block_truncate_page() in ext4
truncate operation instead of ext4_discard_partial_page_buffers().

The statement in the commit description that the truncate operation only
zero block unaligned portion of the last page is not exactly right,
since truncate_pagecache_range() also zeroes and invalidate the unaligned
portion of the page. Then there is no need to zero and unmap it once more
and ext4_block_truncate_page() was doing the right job, although we
still need to update the buffer head containing the last block, which is
exactly what ext4_block_truncate_page() is doing.

Moreover the problem described in the commit is fixed more properly with
commit

15291164b22a357cb211b618adfef4fa82fc0de3
jbd2: clear BH_Delay & BH_Unwritten in journal_unmap_buffer

This was tested on ppc64 machine with block size of 1024 bytes without
any problems.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
---
fs/ext4/extents.c | 13 ++-----------
fs/ext4/indirect.c | 13 ++-----------
2 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5ae1674..5ce5a14 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4271,7 +4271,6 @@ void ext4_ext_truncate(struct inode *inode)
struct super_block *sb = inode->i_sb;
ext4_lblk_t last_block;
handle_t *handle;
- loff_t page_len;
int err = 0;

/*
@@ -4288,16 +4287,8 @@ void ext4_ext_truncate(struct inode *inode)
if (IS_ERR(handle))
return;

- 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 (inode->i_size & (sb->s_blocksize - 1))
+ ext4_block_truncate_page(handle, mapping, inode->i_size);

if (ext4_orphan_add(handle, inode))
goto out_stop;
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 20862f9..48d10b2 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1363,9 +1363,7 @@ void ext4_ind_truncate(struct inode *inode)
__le32 nr = 0;
int n = 0;
ext4_lblk_t last_block, max_block;
- loff_t page_len;
unsigned blocksize = inode->i_sb->s_blocksize;
- int err;

handle = start_transaction(inode);
if (IS_ERR(handle))
@@ -1376,16 +1374,9 @@ void ext4_ind_truncate(struct inode *inode)
max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);

- 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)
+ if (inode->i_size & (blocksize - 1))
+ if (ext4_block_truncate_page(handle, mapping, inode->i_size))
goto out_stop;
- }

if (last_block != max_block) {
n = ext4_block_to_path(inode, last_block, offsets, NULL);