Also Sashiko had something to say about this patch: https://sashiko.dev/#/patchset/20260807010354.2277156-8-liubaolin12138%40163.com
> --- Patch [5]: [PATCH v3 v3 5/7] ntfs3: add allocation tracepoints --- > commit 0592c540bc564c346cb524c624f6ee4a5768406b > Author: Baolin Liu <[email protected]> > > ntfs3: add allocation tracepoints > > This commit adds trace events for ntfs3 allocation operations. It introduces > events for attr_allocate_clusters, attr_set_size_ex, and attr_data_get_block > to help observe cluster allocation, size changes, and block mapping activity. > > > diff --git a/include/trace/events/ntfs3.h b/include/trace/events/ntfs3.h > > index 4ac05ed29e49d..d16dd127ff2e5 100644 > > --- a/include/trace/events/ntfs3.h > > +++ b/include/trace/events/ntfs3.h > [ ... ] > > +TRACE_EVENT(ntfs3_attr_set_size_ex, > > + TP_PROTO(struct inode *inode, u32 type, u64 new_size, bool > > keep_prealloc, > > + bool no_da), > > + TP_ARGS(inode, type, new_size, keep_prealloc, no_da), > > + TP_STRUCT__entry( > > + __field(loff_t, old_size) > > + __field(u64, new_size) > > + __field(unsigned long, ino) > > + __field(dev_t, dev) > > + __field(u32, type) > > + __field(bool, keep_prealloc) > > + __field(bool, no_da) > > + ), > > + TP_fast_assign( > > + __entry->old_size = i_size_read(inode); > > Will this actually record the previous size during truncate operations? > > When an application truncates a file, the VFS size is often updated before > calling into the filesystem. For instance, looking at how ntfs_setattr() > handles this: > > fs/ntfs3/file.c:ntfs_setattr() { > ... > truncate_setsize(inode, newsize); > > err = ntfs_set_size(inode, newsize); > ... > } > > Since truncate_setsize() updates the VFS inode size before attr_set_size_ex() > and this tracepoint are reached, won't i_size_read(inode) just return the > newly truncated size, resulting in old_size equaling new_size? > > Could the actual old size be passed as an explicit parameter to the > tracepoint instead of sampling it here? > > > + __entry->new_size = new_size; > > + __entry->ino = inode->i_ino; > > + __entry->dev = inode->i_sb->s_dev; > > + __entry->type = type; > > + __entry->keep_prealloc = keep_prealloc; > > + __entry->no_da = no_da; > > + ), > [ ... ] -- Steve
