lkml.org 
[lkml]   [2022]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] f2fs: fix the assign logic of iocb
From
On 2022/10/20 0:17, Mukesh Ojha wrote:
> commit 18ae8d12991b ("f2fs: show more DIO information in tracepoint")
> introduces iocb field in 'f2fs_direct_IO_enter' trace event
> And it only assigns the pointer and later it accesses its field
> in trace print log.
>
> Fix it by correcting data type and memcpy the content of iocb.

So the implementation below is wrong, right? since it just assign __entry->name
with dentry->d_name.name rather than copyiny entirely, so that, during printing
of tracepoint, __entry->name may be invalid.

TRACE_EVENT(f2fs_unlink_enter,

TP_PROTO(struct inode *dir, struct dentry *dentry),

TP_ARGS(dir, dentry),

TP_STRUCT__entry(
__field(dev_t, dev)
__field(ino_t, ino)
__field(loff_t, size)
__field(blkcnt_t, blocks)
__field(const char *, name)
),

TP_fast_assign(
__entry->dev = dir->i_sb->s_dev;
__entry->ino = dir->i_ino;
__entry->size = dir->i_size;
__entry->blocks = dir->i_blocks;
__entry->name = dentry->d_name.name;
),

>
> Fixes: 18ae8d12991b ("f2fs: show more DIO information in tracepoint")
> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
> ---
> include/trace/events/f2fs.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index c6b3724..7727ec9 100644
> --- a/include/trace/events/f2fs.h
> +++ b/include/trace/events/f2fs.h
> @@ -940,7 +940,7 @@ TRACE_EVENT(f2fs_direct_IO_enter,
> TP_STRUCT__entry(
> __field(dev_t, dev)
> __field(ino_t, ino)
> - __field(struct kiocb *, iocb)
> + __field_struct(struct kiocb, iocb)
> __field(unsigned long, len)
> __field(int, rw)
> ),
> @@ -948,17 +948,17 @@ TRACE_EVENT(f2fs_direct_IO_enter,
> TP_fast_assign(
> __entry->dev = inode->i_sb->s_dev;
> __entry->ino = inode->i_ino;
> - __entry->iocb = iocb;
> + memcpy(&__entry->iocb, iocb, sizeof(*iocb));
> __entry->len = len;
> __entry->rw = rw;
> ),
>
> TP_printk("dev = (%d,%d), ino = %lu pos = %lld len = %lu ki_flags = %x ki_ioprio = %x rw = %d",
> show_dev_ino(__entry),
> - __entry->iocb->ki_pos,
> + __entry->iocb.ki_pos,
> __entry->len,
> - __entry->iocb->ki_flags,
> - __entry->iocb->ki_ioprio,
> + __entry->iocb.ki_flags,
> + __entry->iocb.ki_ioprio,
> __entry->rw)
> );
>

\
 
 \ /
  Last update: 2022-10-20 11:03    [W:0.060 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site