On Mon 09-05-11 19:18:37, Yongqiang Yang wrote: > On Mon, May 9, 2011 at 7:03 PM, Jan Kara <jack@xxxxxxx> wrote: > > On Sat 07-05-11 16:54:27, Allison Henderson wrote: > >> Fix for a null pointer bug found while running punch hole tests > >> > >> Signed-off-by: Allison Henderson <achender@xxxxxxxxxx> > >> --- > >> :100644 100644 3c7a06e... 3302a6c... M fs/ext4/namei.c > >> fs/ext4/namei.c | 3 ++- > >> 1 files changed, 2 insertions(+), 1 deletions(-) > >> > >> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c > >> index 3c7a06e..3302a6c 100644 > >> --- a/fs/ext4/namei.c > >> +++ b/fs/ext4/namei.c > >> @@ -1422,7 +1422,8 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry, > >> */ > >> ext4_mark_inode_dirty(handle, dir); > >> ext4_handle_dirty_metadata(handle, dir, frame->bh); > >> - ext4_handle_dirty_metadata(handle, dir, bh); > >> + if (bh) > >> + ext4_handle_dirty_metadata(handle, dir, bh); > > I'm puzzled - bh here is bh2 from the beginning of the function and we > > check it for being NULL after we ext4_append() it. So how can this happen? > do_split() encounters a journal error and set bh to NULL before returning. Ah, I see. But then you just reintroduced the bug I was trying to fix. So either do_split() has to do the marking of buffer dirty, or we have to do it before calllig do_split(), or do_split() has to be changed and not release passed buffer (and the two callers have to do it - which they seem to do anyway). I don't mind either way but your fix is wrong. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
