4 files changed, 19 insertions, 0 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 102192c90edd..d17bde5d4f9a 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2780,12 +2780,17 @@ int ceph_get_caps(struct file *filp, int need, int want,
 	struct ceph_file_info *fi = filp->private_data;
 	struct inode *inode = file_inode(filp);
 	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 	int ret, _got, flags;
 
 	ret = ceph_pool_perm_check(inode, need);
 	if (ret < 0)
 		return ret;
 
+	if ((fi->fmode & CEPH_FILE_MODE_WR) &&
+	    fi->filp_gen != READ_ONCE(fsc->filp_gen))
+		return -EBADF;
+
 	while (true) {
 		if (endoff > 0)
 			check_max_size(inode, endoff);
@@ -2814,6 +2819,14 @@ int ceph_get_caps(struct file *filp, int need, int want,
 			if (ret == -EAGAIN)
 				continue;
 		}
+
+		if ((fi->fmode & CEPH_FILE_MODE_WR) &&
+		    fi->filp_gen != READ_ONCE(fsc->filp_gen)) {
+			if (ret >= 0 && _got)
+				ceph_put_cap_refs(ci, _got);
+			return -EBADF;
+		}
+
 		if (ret < 0) {
 			if (ret == -ESTALE) {
 				/* session was killed, try renew caps */
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index fb007b75fb17..779bf68afd60 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -234,6 +234,7 @@ static int ceph_init_file_info(struct inode *inode, struct file *file,
 	spin_lock_init(&fi->rw_contexts_lock);
 	INIT_LIST_HEAD(&fi->rw_contexts);
 	fi->meta_err = errseq_sample(&ci->i_meta_err);
+	fi->filp_gen = READ_ONCE(ceph_inode_to_client(inode)->filp_gen);
 
 	return 0;
 }
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index a95dd13bb628..630549ac4f48 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -664,6 +664,7 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 
 	fsc->sb = NULL;
 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
+	fsc->filp_gen = 1;
 
 	atomic_long_set(&fsc->writeback_count, 0);
 
@@ -829,6 +830,7 @@ static void ceph_umount_begin(struct super_block *sb)
 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
 	ceph_osdc_abort_requests(&fsc->client->osdc, -EIO);
 	ceph_mdsc_force_umount(fsc->mdsc);
+	fsc->filp_gen++; // invalidate open files
 }
 
 static int ceph_remount(struct super_block *sb, int *flags, char *data)
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 736318210bc9..f5e5f6a6bfb8 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -101,6 +101,8 @@ struct ceph_fs_client {
 	struct ceph_client *client;
 
 	unsigned long mount_state;
+
+	u32 filp_gen;
 	loff_t max_file_size;
 
 	struct ceph_mds_client *mdsc;
@@ -707,6 +709,7 @@ struct ceph_file_info {
 	struct list_head rw_contexts;
 
 	errseq_t meta_err;
+	u32 filp_gen;
 	atomic_t num_locks;
 };