smb: client: add tracepoints for deferred handle caching

Add tracepoints to observe handle caching behavior.

smb3_open_cached: emitted when an open reuses a cached handle from
a previous deferred close, avoiding a network round-trip

smb3_close_cached: emitted when a close is deferred (handle cached
for potential reuse by subsequent opens)

Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 4662592801b06d921e72a411c5789e75087de083..79819241ebfdbe1bb4bbd1d543d5f3eca63bd5da 100644 (file)
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -1083,6 +1083,9 @@ int cifs_open(struct inode *inode, struct file *file)
                rc = cfile ? 0 : -ENOENT;
        }
        if (rc == 0) {
+               trace_smb3_open_cached(xid, tcon->tid, tcon->ses->Suid,
+                                      cfile->fid.persistent_fid,
+                                      file->f_flags, cfile->f_flags);
                file->private_data = cfile;
                spin_lock(&CIFS_I(inode)->deferred_lock);
                cifs_del_deferred_close(cfile);
@@ -1442,6 +1445,7 @@ int cifs_close(struct inode *inode, struct file *file)
        struct cifsInodeInfo *cinode = CIFS_I(inode);
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct cifs_deferred_close *dclose;
+       struct cifs_tcon *tcon;
 
        cifs_fscache_unuse_inode_cookie(inode, file->f_mode & FMODE_WRITE);
 
@@ -1468,6 +1472,10 @@ int cifs_close(struct inode *inode, struct file *file)
                                        cifsFileInfo_get(cfile);
                        } else {
                                /* Deferred close for files */
+                               tcon = tlink_tcon(cfile->tlink);
+                               trace_smb3_close_cached(tcon->tid, tcon->ses->Suid,
+                                               cfile->fid.persistent_fid,
+                                               cifs_sb->ctx->closetimeo);
                                queue_delayed_work(deferredclose_wq,
                                                &cfile->deferred, cifs_sb->ctx->closetimeo);
                                cfile->deferred_close_scheduled = true;

diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h
index 57abf5fca26c6bc352dd30725881ef5c6f92e02b..b99ec5a417fad0b6e9ba24cd9294a238df1d1d5a 100644 (file)
--- a/fs/smb/client/trace.h
+++ b/fs/smb/client/trace.h
@@ -1361,6 +1361,57 @@ DEFINE_EVENT(smb3_open_done_class, smb3_##name,  \
 DEFINE_SMB3_OPEN_DONE_EVENT(open_done);
 DEFINE_SMB3_OPEN_DONE_EVENT(posix_mkdir_done);
 
+TRACE_EVENT(smb3_open_cached,
+       TP_PROTO(unsigned int xid,
+               __u32 tid,
+               __u64 sesid,
+               __u64 fid,
+               unsigned int oflags,
+               unsigned int cflags),
+       TP_ARGS(xid, tid, sesid, fid, oflags, cflags),
+       TP_STRUCT__entry(
+               __field(unsigned int, xid)
+               __field(__u32, tid)
+               __field(__u64, sesid)
+               __field(__u64, fid)
+               __field(unsigned int, oflags)
+               __field(unsigned int, cflags)
+       ),
+       TP_fast_assign(
+               __entry->xid = xid;
+               __entry->tid = tid;
+               __entry->sesid = sesid;
+               __entry->fid = fid;
+               __entry->oflags = oflags;
+               __entry->cflags = cflags;
+       ),
+       TP_printk("xid=%u sid=0x%llx tid=0x%x fid=0x%llx oflags=0x%x cflags=0x%x",
+               __entry->xid, __entry->sesid, __entry->tid, __entry->fid,
+               __entry->oflags, __entry->cflags)
+);
+
+TRACE_EVENT(smb3_close_cached,
+       TP_PROTO(__u32 tid,
+               __u64 sesid,
+               __u64 fid,
+               unsigned long delay_jiffies),
+       TP_ARGS(tid, sesid, fid, delay_jiffies),
+       TP_STRUCT__entry(
+               __field(__u32, tid)
+               __field(__u64, sesid)
+               __field(__u64, fid)
+               __field(unsigned long, delay_jiffies)
+       ),
+       TP_fast_assign(
+               __entry->tid = tid;
+               __entry->sesid = sesid;
+               __entry->fid = fid;
+               __entry->delay_jiffies = delay_jiffies;
+       ),
+       TP_printk("sid=0x%llx tid=0x%x fid=0x%llx delay_jiffies=%lu",
+               __entry->sesid, __entry->tid, __entry->fid, __entry->delay_jiffies)
+);
+
 
 DECLARE_EVENT_CLASS(smb3_lease_done_class,
        TP_PROTO(__u32  lease_state,