[PATCH 5/5] cifs: add new field to track the last access time of cfid

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

The handlecache code today tracks the time at which dir lease was
acquired and the laundromat thread uses that to check for old
entries to cleanup.

However, if a directory is actively accessed, it should not
be chosen to expire first.

This change adds a new last_access_time field to cfid and
uses that to decide expiry of the cfid.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/cached_dir.c | 6 ++++--
 fs/smb/client/cached_dir.h | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 9aedb6cf66df..34d21b7d701e 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -212,6 +212,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	 */
 	spin_lock(&cfid->fid_lock);
 	if (cfid->has_lease && cfid->time) {
+		cfid->last_access_time = jiffies;
 		spin_unlock(&cfid->fid_lock);
 		mutex_unlock(&cfid->cfid_mutex);
 		*ret_cfid = cfid;
@@ -365,6 +366,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	cfid->tcon = tcon;
 	cfid->is_open = true;
 	cfid->time = jiffies;
+	cfid->last_access_time = jiffies;
 	spin_unlock(&cfid->fid_lock);
 
 oshr_free:
@@ -739,8 +741,8 @@ static void cfids_laundromat_worker(struct work_struct *work)
 	spin_lock(&cfids->cfid_list_lock);
 	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
 		spin_lock(&cfid->fid_lock);
-		if (cfid->time &&
-		    time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
+		if (cfid->last_access_time &&
+		    time_after(jiffies, cfid->last_access_time + HZ * dir_cache_timeout)) {
 			cfid->on_list = false;
 			list_move(&cfid->entry, &entry);
 			cfids->num_entries--;
diff --git a/fs/smb/client/cached_dir.h b/fs/smb/client/cached_dir.h
index 93c936af2253..6d4b9413aa67 100644
--- a/fs/smb/client/cached_dir.h
+++ b/fs/smb/client/cached_dir.h
@@ -39,6 +39,7 @@ struct cached_fid {
 	bool on_list:1;
 	bool file_all_info_is_valid:1;
 	unsigned long time; /* jiffies of when lease was taken */
+	unsigned long last_access_time; /* jiffies of when last accessed */
 	struct kref refcount;
 	struct cifs_fid fid;
 	spinlock_t fid_lock;
-- 
2.43.0