Seems there is no strict rule to for this case. In fact everybody
just ignored this variable after write_begin() has failed.
This was true until ext4_defrag_partial(). So let's follows simple
rule similar to block_write_begin().
Signed-off-by: Dmitri Monakhov <[email protected]>
---
fs/ext3/inode.c | 2 ++
fs/ext4/inode.c | 1 +
2 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 5fa453b..7aa60db 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1170,6 +1170,7 @@ retry:
if (IS_ERR(handle)) {
unlock_page(page);
page_cache_release(page);
+ *pagep = NULL;
ret = PTR_ERR(handle);
goto out;
}
@@ -1187,6 +1188,7 @@ write_begin_failed:
ext3_journal_stop(handle);
unlock_page(page);
page_cache_release(page);
+ *pagep = NULL;
/*
* block_write_begin may have instantiated a few blocks
* outside i_size. Trim these off again. Don't need
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 658c4a7..0581c48 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1388,6 +1388,7 @@ retry:
unlock_page(page);
ext4_journal_stop(handle);
page_cache_release(page);
+ *pagep = NULL;
/*
* block_write_begin may have instantiated a few blocks
* outside i_size. Trim these off again. Don't need
--
1.5.4.3
On Tue, Feb 17, 2009 at 10:24:19PM +0300, Dmitri Monakhov wrote:
> Seems there is no strict rule to for this case. In fact everybody
> just ignored this variable after write_begin() has failed.
> This was true until ext4_defrag_partial(). So let's follows simple
> rule similar to block_write_begin().
I've checked the latest ext4_defrag_partial, and it doesn't reference
the page variable if write_begin() failed....
- Ted
Theodore Tso <[email protected]> writes:
> On Tue, Feb 17, 2009 at 10:24:19PM +0300, Dmitri Monakhov wrote:
>> Seems there is no strict rule to for this case. In fact everybody
>> just ignored this variable after write_begin() has failed.
>> This was true until ext4_defrag_partial(). So let's follows simple
>> rule similar to block_write_begin().
>
> I've checked the latest ext4_defrag_partial, and it doesn't reference
> the page variable if write_begin() failed....
>
> - Ted
Latest posted defrag version 1.0 from 30 Jan, contains following code
+ up_write(&EXT4_I(org_inode)->i_data_sem);
+ ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags,
+ &page, &fsdata);
+ down_write(&EXT4_I(org_inode)->i_data_sem);
+
+ if (unlikely(ret < 0))
+ goto out;
.....
+out:
+ if (unlikely(page)) {
+ if (PageLocked(page))
+ unlock_page(page);
+ page_cache_release(page);
+ }
In fact the patch i'm propose is mostly a cleanup, rather then serious fix
for real issue. IMHO it is not bad idea to fold it in to some real patch.