cifs: Grab a reference for the dentry of the cached directory during the lifetime of the cache
We need to hold both a reference for the root/superblock as well as the directory that we
are caching. We need to drop these references before we call kill_anon_sb().
At this point, the root and the cached dentries are always the same but this will change
once we start caching other directories as well.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 3ff4600..5864ef6 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -690,6 +690,10 @@ smb2_close_cached_fid(struct kref *ref)
cfid->is_valid = false;
cfid->file_all_info_is_valid = false;
cfid->has_lease = false;
+ if (cfid->dentry) {
+ dput(cfid->dentry);
+ cfid->dentry = NULL;
+ }
}
}
@@ -747,6 +751,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
__le16 utf16_path = 0; /* Null - since an open of top of share */
u8 oplock = SMB2_OPLOCK_LEVEL_II;
struct cifs_fid *pfid;
+ struct dentry *dentry;
if (tcon->nohandlecache)
return -ENOTSUPP;
@@ -757,6 +762,8 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
if (strlen(path))
return -ENOENT;
+ dentry = cifs_sb->root;
+
mutex_lock(&tcon->crfid.fid_mutex);
if (tcon->crfid.is_valid) {
cifs_dbg(FYI, "found a cached root file handle\n");
@@ -881,6 +888,8 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
tcon->crfid.tcon = tcon;
tcon->crfid.is_valid = true;
+ tcon->crfid.dentry = dentry;
+ dget(dentry);
kref_init(&tcon->crfid.refcount);
/* BB TBD check to see if oplock level check can be removed below */