fixes for bugs caught as part of tree-in-dcache work

mostly dentry refcount mishandling
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull dcache fixes from Al Viro:
 "Fixes for bugs caught as part of tree-in-dcache work.

  Mostly dentry refcount mishandling"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  hypfs_create_cpu_files(): add missing check for hypfs_mkdir() failure
  qibfs: fix _another_ leak
  spufs: fix a leak in spufs_create_context()
  spufs: fix gang directory lifetimes
  spufs: fix a leak on spufs_new_file() failure

arch/powerpc/platforms/cell/spufs/gang.c

@@ -25,6 +25,7 @@ struct spu_gang *alloc_spu_gang(void)
 	mutex_init(&gang->aff_mutex);
 	INIT_LIST_HEAD(&gang->list);
 	INIT_LIST_HEAD(&gang->aff_list_head);
+	gang->alive = 1;
 
 out:
 	return gang;

arch/powerpc/platforms/cell/spufs/inode.c

@@ -192,13 +192,32 @@ static int spufs_fill_dir(struct dentry *dir,
 			return -ENOMEM;
 		ret = spufs_new_file(dir->d_sb, dentry, files->ops,
 					files->mode & mode, files->size, ctx);
-		if (ret)
+		if (ret) {
+			dput(dentry);
 			return ret;
+		}
 		files++;
 	}
 	return 0;
 }
 
+static void unuse_gang(struct dentry *dir)
+{
+	struct inode *inode = dir->d_inode;
+	struct spu_gang *gang = SPUFS_I(inode)->i_gang;
+
+	if (gang) {
+		bool dead;
+
+		inode_lock(inode); // exclusion with spufs_create_context()
+		dead = !--gang->alive;
+		inode_unlock(inode);
+
+		if (dead)
+			simple_recursive_removal(dir, NULL);
+	}
+}
+
 static int spufs_dir_close(struct inode *inode, struct file *file)
 {
 	struct inode *parent;
@@ -213,6 +232,7 @@ static int spufs_dir_close(struct inode *inode, struct file *file)
 	inode_unlock(parent);
 	WARN_ON(ret);
 
+	unuse_gang(dir->d_parent);
 	return dcache_dir_close(inode, file);
 }
 
@@ -405,7 +425,7 @@ spufs_create_context(struct inode *inode, struct dentry *dentry,
 {
 	int ret;
 	int affinity;
-	struct spu_gang *gang;
+	struct spu_gang *gang = SPUFS_I(inode)->i_gang;
 	struct spu_context *neighbor;
 	struct path path = {.mnt = mnt, .dentry = dentry};
 
@@ -420,11 +440,15 @@ spufs_create_context(struct inode *inode, struct dentry *dentry,
 	if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader)
 		return -ENODEV;
 
-	gang = NULL;
+	if (gang) {
+		if (!gang->alive)
+			return -ENOENT;
+		gang->alive++;
+	}
+
 	neighbor = NULL;
 	affinity = flags & (SPU_CREATE_AFFINITY_MEM | SPU_CREATE_AFFINITY_SPU);
 	if (affinity) {
-		gang = SPUFS_I(inode)->i_gang;
 		if (!gang)
 			return -EINVAL;
 		mutex_lock(&gang->aff_mutex);
@@ -436,8 +460,11 @@ spufs_create_context(struct inode *inode, struct dentry *dentry,
 	}
 
 	ret = spufs_mkdir(inode, dentry, flags, mode & 0777);
-	if (ret)
+	if (ret) {
+		if (neighbor)
+			put_spu_context(neighbor);
 		goto out_aff_unlock;
+	}
 
 	if (affinity) {
 		spufs_set_affinity(flags, SPUFS_I(d_inode(dentry))->i_ctx,
@@ -453,6 +480,8 @@ spufs_create_context(struct inode *inode, struct dentry *dentry,
 out_aff_unlock:
 	if (affinity)
 		mutex_unlock(&gang->aff_mutex);
+	if (ret && gang)
+		gang->alive--; // can't reach 0
 	return ret;
 }
 
@@ -482,6 +511,7 @@ spufs_mkgang(struct inode *dir, struct dentry *dentry, umode_t mode)
 	inode->i_fop = &simple_dir_operations;
 
 	d_instantiate(dentry, inode);
+	dget(dentry);
 	inc_nlink(dir);
 	inc_nlink(d_inode(dentry));
 	return ret;
@@ -492,6 +522,21 @@ out:
 	return ret;
 }
 
+static int spufs_gang_close(struct inode *inode, struct file *file)
+{
+	unuse_gang(file->f_path.dentry);
+	return dcache_dir_close(inode, file);
+}
+
+static const struct file_operations spufs_gang_fops = {
+	.open		= dcache_dir_open,
+	.release	= spufs_gang_close,
+	.llseek		= dcache_dir_lseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= dcache_readdir,
+	.fsync		= noop_fsync,
+};
+
 static int spufs_gang_open(const struct path *path)
 {
 	int ret;
@@ -511,7 +556,7 @@ static int spufs_gang_open(const struct path *path)
 		return PTR_ERR(filp);
 	}
 
-	filp->f_op = &simple_dir_operations;
+	filp->f_op = &spufs_gang_fops;
 	fd_install(ret, filp);
 	return ret;
 }
@@ -526,10 +571,8 @@ static int spufs_create_gang(struct inode *inode,
 	ret = spufs_mkgang(inode, dentry, mode & 0777);
 	if (!ret) {
 		ret = spufs_gang_open(&path);
-		if (ret < 0) {
-			int err = simple_rmdir(inode, dentry);
-			WARN_ON(err);
-		}
+		if (ret < 0)
+			unuse_gang(dentry);
 	}
 	return ret;
 }

arch/powerpc/platforms/cell/spufs/spufs.h

@@ -151,6 +151,8 @@ struct spu_gang {
 	int aff_flags;
 	struct spu *aff_ref_spu;
 	atomic_t aff_sched_count;
+
+	int alive;
 };
 
 /* Flag bits for spu_gang aff_flags */

arch/s390/hypfs/hypfs_diag_fs.c

@@ -209,6 +209,8 @@ static int hypfs_create_cpu_files(struct dentry *cpus_dir, void *cpu_info)
 	snprintf(buffer, TMP_SIZE, "%d", cpu_info__cpu_addr(diag204_get_info_type(),
 							    cpu_info));
 	cpu_dir = hypfs_mkdir(cpus_dir, buffer);
+	if (IS_ERR(cpu_dir))
+		return PTR_ERR(cpu_dir);
 	rc = hypfs_create_u64(cpu_dir, "mgmtime",
 			      cpu_info__acc_time(diag204_get_info_type(), cpu_info) -
 			      cpu_info__lp_time(diag204_get_info_type(), cpu_info));

drivers/infiniband/hw/qib/qib_fs.c

@@ -55,6 +55,7 @@ static int qibfs_mknod(struct inode *dir, struct dentry *dentry,
 	struct inode *inode = new_inode(dir->i_sb);
 
 	if (!inode) {
+		dput(dentry);
 		error = -EPERM;
 		goto bail;
 	}