diff options
| author | Tejun Heo <tj@kernel.org> | 2019-08-31 02:39:54 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-08-31 04:54:28 +0300 |
| commit | 0feacaa21634014148068035b02eade71f853496 (patch) | |
| tree | c20571682d26e50058ed4d6ac54b4a9149f08dab /include/trace | |
| parent | 8f5914bceef03827c3feb413874b2e6f29c821be (diff) | |
| download | linux-0feacaa21634014148068035b02eade71f853496.tar.xz | |
writeback: don't access page->mapping directly in track_foreign_dirty TP
page->mapping may encode different values in it and page_mapping()
should always be used to access the mapping pointer.
track_foreign_dirty tracepoint was incorrectly accessing page->mapping
directly. Use page_mapping() instead. Also, add NULL checks while at
it.
Fixes: 3a8e9ac89e6a ("writeback: add tracepoints for cgroup foreign writebacks")
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/writeback.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 3dc9fb9e7c78..3a27335fce2c 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -251,9 +251,12 @@ TRACE_EVENT(track_foreign_dirty, ), TP_fast_assign( + struct address_space *mapping = page_mapping(page); + struct inode *inode = mapping ? mapping->host : NULL; + strncpy(__entry->name, dev_name(wb->bdi->dev), 32); __entry->bdi_id = wb->bdi->id; - __entry->ino = page->mapping->host->i_ino; + __entry->ino = inode ? inode->i_ino : 0; __entry->memcg_id = wb->memcg_css->id; __entry->cgroup_ino = __trace_wb_assign_cgroup(wb); __entry->page_cgroup_ino = page->mem_cgroup->css.cgroup->kn->id.ino; |