cifs: Grab a reference for the dentry of the cached directory during the lifetime...

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/cifsfs.c b/fs/cifs/cifsfs.c
index cf8eceb..4257f84 100644 (file)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -257,11 +257,28 @@ out_no_root:
 static void cifs_kill_sb(struct super_block *sb)
 {
        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+       struct cifs_tcon *tcon;
+       struct cached_fid *cfid;
 
+       /*
+        * We ned to release all dentries for the cached directories
+        * before we kill the sb.
+        */
        if (cifs_sb->root) {
                dput(cifs_sb->root);
                cifs_sb->root = NULL;
        }
+       tcon = cifs_sb_master_tcon(cifs_sb);
+       if (tcon) {
+               cfid = &tcon->crfid;
+               mutex_lock(&cfid->fid_mutex);
+               if (cfid->dentry) {
+
+                       dput(cfid->dentry);
+                       cfid->dentry = NULL;
+               }
+               mutex_unlock(&cfid->fid_mutex);
+       }
 
        kill_anon_super(sb);
        cifs_umount(cifs_sb);

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 034b919..64a1095 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -992,6 +992,7 @@ struct cached_fid {
        struct cifs_fid *fid;
        struct mutex fid_mutex;
        struct cifs_tcon *tcon;
+       struct dentry *dentry;
        struct work_struct lease_break;
        struct smb2_file_all_info file_all_info;
 };

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 3ff4600..5864ef6 100644 (file)
--- 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 */