cifs: use a refcount to protect open/closing the cached file handle (9da6ec77) · Commits · 戴 / test

fs/cifs/cifsglob.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -907,6 +907,7 @@ cap_unix(struct cifs_ses *ses)

		struct cached_fid {
		bool is_valid:1; /* Do we have a useable root fid */
		struct kref refcount;
		struct cifs_fid *fid;
		struct mutex fid_mutex;
		struct cifs_tcon *tcon;

fs/cifs/smb2inode.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -120,7 +120,9 @@ smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon,
		break;
		}

		if (use_cached_root_handle == false)
		if (use_cached_root_handle)
		close_shroot(&tcon->crfid);
		else
		rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
		if (tmprc)
		rc = tmprc;

fs/cifs/smb2ops.c

+26 −5

Original line number	Diff line number	Diff line
		@@ -470,21 +470,36 @@ out:
		return rc;
		}

		void
		smb2_cached_lease_break(struct work_struct *work)
		static void
		smb2_close_cached_fid(struct kref *ref)
		{
		struct cached_fid *cfid = container_of(work,
		struct cached_fid, lease_break);
		mutex_lock(&cfid->fid_mutex);
		struct cached_fid *cfid = container_of(ref, struct cached_fid,
		refcount);

		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;
		}
		}

		void close_shroot(struct cached_fid *cfid)
		{
		mutex_lock(&cfid->fid_mutex);
		kref_put(&cfid->refcount, smb2_close_cached_fid);
		mutex_unlock(&cfid->fid_mutex);
		}

		void
		smb2_cached_lease_break(struct work_struct *work)
		{
		struct cached_fid *cfid = container_of(work,
		struct cached_fid, lease_break);

		close_shroot(cfid);
		}

		/*
		* Open the directory at the root of a share
		*/
		@@ -499,6 +514,7 @@ int open_shroot(unsigned int xid, struct cifs_tcon tcon, struct cifs_fid pfid)
		if (tcon->crfid.is_valid) {
		cifs_dbg(FYI, "found a cached root file handle\n");
		memcpy(pfid, tcon->crfid.fid, sizeof(struct cifs_fid));
		kref_get(&tcon->crfid.refcount);
		mutex_unlock(&tcon->crfid.fid_mutex);
		return 0;
		}
		@@ -515,6 +531,8 @@ int open_shroot(unsigned int xid, struct cifs_tcon tcon, struct cifs_fid pfid)
		memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
		tcon->crfid.tcon = tcon;
		tcon->crfid.is_valid = true;
		kref_init(&tcon->crfid.refcount);
		kref_get(&tcon->crfid.refcount);
		}
		mutex_unlock(&tcon->crfid.fid_mutex);
		return rc;
		@@ -558,6 +576,9 @@ smb3_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
		FS_SECTOR_SIZE_INFORMATION); /* SMB3 specific */
		if (no_cached_open)
		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
		else
		close_shroot(&tcon->crfid);

		return;
		}

fs/cifs/smb2proto.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -68,6 +68,7 @@ extern int smb3_handle_read_data(struct TCP_Server_Info *server,

		extern int open_shroot(unsigned int xid, struct cifs_tcon *tcon,
		struct cifs_fid *pfid);
		extern void close_shroot(struct cached_fid *cfid);
		extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst,
		struct smb2_file_all_info *src);
		extern int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,

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