cifs: add lease tracking to the cached root fid

Use a read lease for the cached root fid so that we can detect
when the content of the directory changes (via a break) at which time
we close the handle. On next access to the root the handle will be reopened
and cached again.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 1efa2e65bc1a8971f01811ac699a82cb7c1f1727..ff71fbd619bfaaeff4539c5890d8dab16fe4cd4b 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -883,6 +883,14 @@ cap_unix(struct cifs_ses *ses)
        return ses->server->vals->cap_unix & ses->capabilities;
 }
 
+struct cached_fid {
+       bool is_valid:1;        /* Do we have a useable root fid */
+       struct cifs_fid *fid;
+       struct mutex fid_mutex;
+       struct cifs_tcon *tcon;
+       struct work_struct lease_break;
+};
+
 /*
  * there is one of these for each connection to a resource on a particular
  * session
@@ -987,9 +995,7 @@ struct cifs_tcon {
        struct fscache_cookie *fscache; /* cookie for share */
 #endif
        struct list_head pending_opens; /* list of incomplete opens */
-       bool valid_root_fid:1;  /* Do we have a useable root fid */
-       struct mutex prfid_mutex; /* prevents reopen race after dead ses*/
-       struct cifs_fid *prfid; /* handle to the directory at top of share */
+       struct cached_fid crfid; /* Cached root fid */
        /* BB add field for back pointer to sb struct(s)? */
 };
 

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 4e0d183c3d1016918d9934420af6e626d128d077..3a13b44069fe5d5db286a436376b592c8084bf96 100644 (file)
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -552,6 +552,7 @@ enum securityEnum cifs_select_sectype(struct TCP_Server_Info *,
 struct cifs_aio_ctx *cifs_aio_ctx_alloc(void);
 void cifs_aio_ctx_release(struct kref *refcount);
 int setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw);
+void smb2_cached_lease_break(struct work_struct *work);
 
 int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
                    struct sdesc **sdesc);

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 42329b25877db2b3de349b0ce5723f70bebad92b..d352da325de34d3c11b6dbb8c6579f6e4f0a216f 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -107,10 +107,10 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon)
        }
        spin_unlock(&tcon->open_file_lock);
 
-       mutex_lock(&tcon->prfid_mutex);
-       tcon->valid_root_fid = false;
-       memset(tcon->prfid, 0, sizeof(struct cifs_fid));
-       mutex_unlock(&tcon->prfid_mutex);
+       mutex_lock(&tcon->crfid.fid_mutex);
+       tcon->crfid.is_valid = false;
+       memset(tcon->crfid.fid, 0, sizeof(struct cifs_fid));
+       mutex_unlock(&tcon->crfid.fid_mutex);
 
        /*
         * BB Add call to invalidate_inodes(sb) for all superblocks mounted

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index af29ade195c002c0323d855edb391a155f1620f7..bb40f3c050f6a6fb18118792bfb0572db6c39178 100644 (file)
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -117,8 +117,9 @@ tconInfoAlloc(void)
                INIT_LIST_HEAD(&ret_buf->openFileList);
                INIT_LIST_HEAD(&ret_buf->tcon_list);
                spin_lock_init(&ret_buf->open_file_lock);
-               mutex_init(&ret_buf->prfid_mutex);
-               ret_buf->prfid = kzalloc(sizeof(struct cifs_fid), GFP_KERNEL);
+               mutex_init(&ret_buf->crfid.fid_mutex);
+               ret_buf->crfid.fid = kzalloc(sizeof(struct cifs_fid),
+                                            GFP_KERNEL);
 #ifdef CONFIG_CIFS_STATS
                spin_lock_init(&ret_buf->stat_lock);
 #endif
@@ -136,7 +137,7 @@ tconInfoFree(struct cifs_tcon *buf_to_free)
        atomic_dec(&tconInfoAllocCount);
        kfree(buf_to_free->nativeFileSystem);
        kzfree(buf_to_free->password);
-       kfree(buf_to_free->prfid);
+       kfree(buf_to_free->crfid.fid);
        kfree(buf_to_free);
 }
 

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index e2bec47c684580089a70e7914ec71d2f523da3e3..0de87ca33e2e2cc8192a94475aecd4b9c5f5a064 100644 (file)
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -492,10 +492,11 @@ cifs_ses_oplock_break(struct work_struct *work)
 {
        struct smb2_lease_break_work *lw = container_of(work,
                                struct smb2_lease_break_work, lease_break);
-       int rc;
+       int rc = 0;
 
        rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
                              lw->lease_state);
+
        cifs_dbg(FYI, "Lease release rc %d\n", rc);
        cifs_put_tlink(lw->tlink);
        kfree(lw);
@@ -561,6 +562,7 @@ smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
 
                open->oplock = lease_state;
        }
+
        return found;
 }
 
@@ -603,6 +605,18 @@ smb2_is_valid_lease_break(char *buffer)
                                        return true;
                                }
                                spin_unlock(&tcon->open_file_lock);
+
+                               if (tcon->crfid.is_valid &&
+                                   !memcmp(rsp->LeaseKey,
+                                           tcon->crfid.fid->lease_key,
+                                           SMB2_LEASE_KEY_SIZE)) {
+                                       INIT_WORK(&tcon->crfid.lease_break,
+                                                 smb2_cached_lease_break);
+                                       queue_work(cifsiod_wq,
+                                                  &tcon->crfid.lease_break);
+                                       spin_unlock(&cifs_tcp_ses_lock);
+                                       return true;
+                               }
                        }
                }
        }

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b15f5957d64591f0af611670088dd4dd8439fb43..682bcfa246be5f42438c2d7486d76260364ac52b 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -323,6 +323,21 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
 }
 #endif /* STATS2 */
 
+void
+smb2_cached_lease_break(struct work_struct *work)
+{
+       struct cached_fid *cfid = container_of(work,
+                               struct cached_fid, lease_break);
+       mutex_lock(&cfid->fid_mutex);
+       if (cfid->is_valid) {
+               cifs_dbg(FYI, "clear cached root file handle\n");
+               SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,
+                          cfid->fid->volatile_fid);
+               cfid->is_valid = false;
+       }
+       mutex_unlock(&cfid->fid_mutex);
+}
+
 /*
  * Open the directory at the root of a share
  */
@@ -331,13 +346,13 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
        struct cifs_open_parms oparams;
        int rc;
        __le16 srch_path = 0; /* Null - since an open of top of share */
-       u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
+       u8 oplock = SMB2_OPLOCK_LEVEL_II;
 
-       mutex_lock(&tcon->prfid_mutex);
-       if (tcon->valid_root_fid) {
+       mutex_lock(&tcon->crfid.fid_mutex);
+       if (tcon->crfid.is_valid) {
                cifs_dbg(FYI, "found a cached root file handle\n");
-               memcpy(pfid, tcon->prfid, sizeof(struct cifs_fid));
-               mutex_unlock(&tcon->prfid_mutex);
+               memcpy(pfid, tcon->crfid.fid, sizeof(struct cifs_fid));
+               mutex_unlock(&tcon->crfid.fid_mutex);
                return 0;
        }
 
@@ -350,10 +365,11 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
 
        rc = SMB2_open(xid, &oparams, &srch_path, &oplock, NULL, NULL, NULL);
        if (rc == 0) {
-               memcpy(tcon->prfid, pfid, sizeof(struct cifs_fid));
-               tcon->valid_root_fid = true;
+               memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
+               tcon->crfid.tcon = tcon;
+               tcon->crfid.is_valid = true;
        }
-       mutex_unlock(&tcon->prfid_mutex);
+       mutex_unlock(&tcon->crfid.fid_mutex);
        return rc;
 }
 
@@ -436,7 +452,7 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
 
-       if ((*full_path == 0) && tcon->valid_root_fid)
+       if ((*full_path == 0) && tcon->crfid.is_valid)
                return 0;
 
        utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);