6 files changed, 195 insertions, 118 deletions

diff --git a/arch/s390/hypfs/Makefile b/arch/s390/hypfs/Makefile
index b08d2abf6178..2e671d5004ca 100644
--- a/arch/s390/hypfs/Makefile
+++ b/arch/s390/hypfs/Makefile
@@ -4,4 +4,4 @@
 
 obj-$(CONFIG_S390_HYPFS_FS) += s390_hypfs.o
 
-s390_hypfs-objs := inode.o hypfs_diag.o hypfs_vm.o
+s390_hypfs-objs := inode.o hypfs_diag.o hypfs_vm.o hypfs_dbfs.o
diff --git a/arch/s390/hypfs/hypfs.h b/arch/s390/hypfs/hypfs.h
index fa487d4cc08b..80c1526f2af3 100644
--- a/arch/s390/hypfs/hypfs.h
+++ b/arch/s390/hypfs/hypfs.h
@@ -12,6 +12,8 @@
 #include <linux/fs.h>
 #include <linux/types.h>
 #include <linux/debugfs.h>
+#include <linux/workqueue.h>
+#include <linux/kref.h>
 
 #define REG_FILE_MODE    0440
 #define UPDATE_FILE_MODE 0220
@@ -38,6 +40,33 @@ extern int hypfs_vm_init(void);
 extern void hypfs_vm_exit(void);
 extern int hypfs_vm_create_files(struct super_block *sb, struct dentry *root);
 
-/* Directory for debugfs files */
-extern struct dentry *hypfs_dbfs_dir;
+/* debugfs interface */
+struct hypfs_dbfs_file;
+
+struct hypfs_dbfs_data {
+        void                    *buf;
+        void                    *buf_free_ptr;
+        size_t                  size;
+        struct hypfs_dbfs_file  *dbfs_file;;
+        struct kref             kref;
+};
+
+struct hypfs_dbfs_file {
+        const char      *name;
+        int             (*data_create)(void **data, void **data_free_ptr,
+                                       size_t *size);
+        void            (*data_free)(const void *buf_free_ptr);
+
+        /* Private data for hypfs_dbfs.c */
+        struct hypfs_dbfs_data  *data;
+        struct delayed_work     data_free_work;
+        struct mutex            lock;
+        struct dentry           *dentry;
+};
+
+extern int hypfs_dbfs_init(void);
+extern void hypfs_dbfs_exit(void);
+extern int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df);
+extern void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df);
+
 #endif /* _HYPFS_H_ */
diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c
new file mode 100644
index 000000000000..b478013b7fec
--- /dev/null
+++ b/arch/s390/hypfs/hypfs_dbfs.c
@@ -0,0 +1,116 @@
+/*
+ * Hypervisor filesystem for Linux on s390 - debugfs interface
+ *
+ * Copyright (C) IBM Corp. 2010
+ * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/slab.h>
+#include "hypfs.h"
+
+static struct dentry *dbfs_dir;
+
+static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f)
+{
+        struct hypfs_dbfs_data *data;
+
+        data = kmalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                return NULL;
+        kref_init(&data->kref);
+        data->dbfs_file = f;
+        return data;
+}
+
+static void hypfs_dbfs_data_free(struct kref *kref)
+{
+        struct hypfs_dbfs_data *data;
+
+        data = container_of(kref, struct hypfs_dbfs_data, kref);
+        data->dbfs_file->data_free(data->buf_free_ptr);
+        kfree(data);
+}
+
+static void data_free_delayed(struct work_struct *work)
+{
+        struct hypfs_dbfs_data *data;
+        struct hypfs_dbfs_file *df;
+
+        df = container_of(work, struct hypfs_dbfs_file, data_free_work.work);
+        mutex_lock(&df->lock);
+        data = df->data;
+        df->data = NULL;
+        mutex_unlock(&df->lock);
+        kref_put(&data->kref, hypfs_dbfs_data_free);
+}
+
+static ssize_t dbfs_read(struct file *file, char __user *buf,
+                         size_t size, loff_t *ppos)
+{
+        struct hypfs_dbfs_data *data;
+        struct hypfs_dbfs_file *df;
+        ssize_t rc;
+
+        if (*ppos != 0)
+                return 0;
+
+        df = file->f_path.dentry->d_inode->i_private;
+        mutex_lock(&df->lock);
+        if (!df->data) {
+                data = hypfs_dbfs_data_alloc(df);
+                if (!data) {
+                        mutex_unlock(&df->lock);
+                        return -ENOMEM;
+                }
+                rc = df->data_create(&data->buf, &data->buf_free_ptr,
+                                     &data->size);
+                if (rc) {
+                        mutex_unlock(&df->lock);
+                        kfree(data);
+                        return rc;
+                }
+                df->data = data;
+                schedule_delayed_work(&df->data_free_work, HZ);
+        }
+        data = df->data;
+        kref_get(&data->kref);
+        mutex_unlock(&df->lock);
+
+        rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
+        kref_put(&data->kref, hypfs_dbfs_data_free);
+        return rc;
+}
+
+static const struct file_operations dbfs_ops = {
+        .read           = dbfs_read,
+        .llseek         = no_llseek,
+};
+
+int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
+{
+        df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df,
+                                         &dbfs_ops);
+        if (IS_ERR(df->dentry))
+                return PTR_ERR(df->dentry);
+        mutex_init(&df->lock);
+        INIT_DELAYED_WORK(&df->data_free_work, data_free_delayed);
+        return 0;
+}
+
+void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df)
+{
+        debugfs_remove(df->dentry);
+}
+
+int hypfs_dbfs_init(void)
+{
+        dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
+        if (IS_ERR(dbfs_dir))
+                return PTR_ERR(dbfs_dir);
+        return 0;
+}
+
+void hypfs_dbfs_exit(void)
+{
+        debugfs_remove(dbfs_dir);
+}
diff --git a/arch/s390/hypfs/hypfs_diag.c b/arch/s390/hypfs/hypfs_diag.c
index cd4a81be9cf8..6023c6dc1fb7 100644
--- a/arch/s390/hypfs/hypfs_diag.c
+++ b/arch/s390/hypfs/hypfs_diag.c
@@ -555,81 +555,38 @@ struct dbfs_d204 {
         char                    buf[];  /* d204 buffer */
 } __attribute__ ((packed));
 
-struct dbfs_d204_private {
-        struct dbfs_d204        *d204;  /* Aligned d204 data with header */
-        void                    *base;  /* Base pointer (needed for vfree) */
-};
-
-static int dbfs_d204_open(struct inode *inode, struct file *file)
+static int dbfs_d204_create(void **data, void **data_free_ptr, size_t *size)
 {
-        struct dbfs_d204_private *data;
         struct dbfs_d204 *d204;
         int rc, buf_size;
+        void *base;
 
-        data = kzalloc(sizeof(*data), GFP_KERNEL);
-        if (!data)
-                return -ENOMEM;
         buf_size = PAGE_SIZE * (diag204_buf_pages + 1) + sizeof(d204->hdr);
-        data->base = vmalloc(buf_size);
-        if (!data->base) {
-                rc = -ENOMEM;
-                goto fail_kfree_data;
+        base = vmalloc(buf_size);
+        if (!base)
+                return -ENOMEM;
+        memset(base, 0, buf_size);
+        d204 = page_align_ptr(base + sizeof(d204->hdr)) - sizeof(d204->hdr);
+        rc = diag204_do_store(d204->buf, diag204_buf_pages);
+        if (rc) {
+                vfree(base);
+                return rc;
         }
-        memset(data->base, 0, buf_size);
-        d204 = page_align_ptr(data->base + sizeof(d204->hdr))
-                - sizeof(d204->hdr);
-        rc = diag204_do_store(&d204->buf, diag204_buf_pages);
-        if (rc)
-                goto fail_vfree_base;
         d204->hdr.version = DBFS_D204_HDR_VERSION;
         d204->hdr.len = PAGE_SIZE * diag204_buf_pages;
         d204->hdr.sc = diag204_store_sc;
-        data->d204 = d204;
-        file->private_data = data;
-        return nonseekable_open(inode, file);
-
-fail_vfree_base:
-        vfree(data->base);
-fail_kfree_data:
-        kfree(data);
-        return rc;
-}
-
-static int dbfs_d204_release(struct inode *inode, struct file *file)
-{
-        struct dbfs_d204_private *data = file->private_data;
-
-        vfree(data->base);
-        kfree(data);
+        *data = d204;
+        *data_free_ptr = base;
+        *size = d204->hdr.len + sizeof(struct dbfs_d204_hdr);
         return 0;
 }
 
-static ssize_t dbfs_d204_read(struct file *file, char __user *buf,
-                              size_t size, loff_t *ppos)
-{
-        struct dbfs_d204_private *data = file->private_data;
-
-        return simple_read_from_buffer(buf, size, ppos, data->d204,
-                                       data->d204->hdr.len +
-                                       sizeof(data->d204->hdr));
-}
-
-static const struct file_operations dbfs_d204_ops = {
-        .open           = dbfs_d204_open,
-        .read           = dbfs_d204_read,
-        .release        = dbfs_d204_release,
-        .llseek         = no_llseek,
+static struct hypfs_dbfs_file dbfs_file_d204 = {
+        .name           = "diag_204",
+        .data_create    = dbfs_d204_create,
+        .data_free      = vfree,
 };
 
-static int hypfs_dbfs_init(void)
-{
-        dbfs_d204_file = debugfs_create_file("diag_204", 0400, hypfs_dbfs_dir,
-                                             NULL, &dbfs_d204_ops);
-        if (IS_ERR(dbfs_d204_file))
-                return PTR_ERR(dbfs_d204_file);
-        return 0;
-}
-
 __init int hypfs_diag_init(void)
 {
         int rc;
@@ -639,7 +596,7 @@ __init int hypfs_diag_init(void)
                 return -ENODATA;
         }
         if (diag204_info_type == INFO_EXT) {
-                rc = hypfs_dbfs_init();
+                rc = hypfs_dbfs_create_file(&dbfs_file_d204);
                 if (rc)
                         return rc;
         }
@@ -660,6 +617,7 @@ void hypfs_diag_exit(void)
         debugfs_remove(dbfs_d204_file);
         diag224_delete_name_table();
         diag204_free_buffer();
+        hypfs_dbfs_remove_file(&dbfs_file_d204);
 }
 
 /*
diff --git a/arch/s390/hypfs/hypfs_vm.c b/arch/s390/hypfs/hypfs_vm.c
index 26cf177f6a3a..e54796002f61 100644
--- a/arch/s390/hypfs/hypfs_vm.c
+++ b/arch/s390/hypfs/hypfs_vm.c
@@ -20,8 +20,6 @@ static char local_guest[] = "        ";
 static char all_guests[] = "*       ";
 static char *guest_query;
 
-static struct dentry *dbfs_d2fc_file;
-
 struct diag2fc_data {
         __u32 version;
         __u32 flags;
@@ -104,7 +102,7 @@ static void *diag2fc_store(char *query, unsigned int *count, int offset)
         return data;
 }
 
-static void diag2fc_free(void *data)
+static void diag2fc_free(const void *data)
 {
         vfree(data);
 }
@@ -239,43 +237,29 @@ struct dbfs_d2fc {
         char                    buf[];  /* d2fc buffer */
 } __attribute__ ((packed));
 
-static int dbfs_d2fc_open(struct inode *inode, struct file *file)
+static int dbfs_diag2fc_create(void **data, void **data_free_ptr, size_t *size)
 {
-        struct dbfs_d2fc *data;
+        struct dbfs_d2fc *d2fc;
         unsigned int count;
 
-        data = diag2fc_store(guest_query, &count, sizeof(data->hdr));
-        if (IS_ERR(data))
-                return PTR_ERR(data);
-        get_clock_ext(data->hdr.tod_ext);
-        data->hdr.len = count * sizeof(struct diag2fc_data);
-        data->hdr.version = DBFS_D2FC_HDR_VERSION;
-        data->hdr.count = count;
-        memset(&data->hdr.reserved, 0, sizeof(data->hdr.reserved));
-        file->private_data = data;
-        return nonseekable_open(inode, file);
-}
-
-static int dbfs_d2fc_release(struct inode *inode, struct file *file)
-{
-        diag2fc_free(file->private_data);
+        d2fc = diag2fc_store(guest_query, &count, sizeof(d2fc->hdr));
+        if (IS_ERR(d2fc))
+                return PTR_ERR(d2fc);
+        get_clock_ext(d2fc->hdr.tod_ext);
+        d2fc->hdr.len = count * sizeof(struct diag2fc_data);
+        d2fc->hdr.version = DBFS_D2FC_HDR_VERSION;
+        d2fc->hdr.count = count;
+        memset(&d2fc->hdr.reserved, 0, sizeof(d2fc->hdr.reserved));
+        *data = d2fc;
+        *data_free_ptr = d2fc;
+        *size = d2fc->hdr.len + sizeof(struct dbfs_d2fc_hdr);
         return 0;
 }
 
-static ssize_t dbfs_d2fc_read(struct file *file, char __user *buf,
-                                    size_t size, loff_t *ppos)
-{
-        struct dbfs_d2fc *data = file->private_data;
-
-        return simple_read_from_buffer(buf, size, ppos, data, data->hdr.len +
-                                       sizeof(struct dbfs_d2fc_hdr));
-}
-
-static const struct file_operations dbfs_d2fc_ops = {
-        .open           = dbfs_d2fc_open,
-        .read           = dbfs_d2fc_read,
-        .release        = dbfs_d2fc_release,
-        .llseek         = no_llseek,
+static struct hypfs_dbfs_file dbfs_file_2fc = {
+        .name           = "diag_2fc",
+        .data_create    = dbfs_diag2fc_create,
+        .data_free      = diag2fc_free,
 };
 
 int hypfs_vm_init(void)
@@ -288,18 +272,12 @@ int hypfs_vm_init(void)
                 guest_query = local_guest;
         else
                 return -EACCES;
-
-        dbfs_d2fc_file = debugfs_create_file("diag_2fc", 0400, hypfs_dbfs_dir,
-                                             NULL, &dbfs_d2fc_ops);
-        if (IS_ERR(dbfs_d2fc_file))
-                return PTR_ERR(dbfs_d2fc_file);
-
-        return 0;
+        return hypfs_dbfs_create_file(&dbfs_file_2fc);
 }
 
 void hypfs_vm_exit(void)
 {
         if (!MACHINE_IS_VM)
                 return;
-        debugfs_remove(dbfs_d2fc_file);
+        hypfs_dbfs_remove_file(&dbfs_file_2fc);
 }
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 47cc446dab8f..6fe874fc5f8e 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -46,8 +46,6 @@ static const struct super_operations hypfs_s_ops;
 /* start of list of all dentries, which have to be deleted on update */
 static struct dentry *hypfs_last_dentry;
 
-struct dentry *hypfs_dbfs_dir;
-
 static void hypfs_update_update(struct super_block *sb)
 {
         struct hypfs_sb_info *sb_info = sb->s_fs_info;
@@ -471,13 +469,12 @@ static int __init hypfs_init(void)
 {
         int rc;
 
-        hypfs_dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
-        if (IS_ERR(hypfs_dbfs_dir))
-                return PTR_ERR(hypfs_dbfs_dir);
-
+        rc = hypfs_dbfs_init();
+        if (rc)
+                return rc;
         if (hypfs_diag_init()) {
                 rc = -ENODATA;
-                goto fail_debugfs_remove;
+                goto fail_dbfs_exit;
         }
         if (hypfs_vm_init()) {
                 rc = -ENODATA;
@@ -499,9 +496,8 @@ fail_hypfs_vm_exit:
         hypfs_vm_exit();
 fail_hypfs_diag_exit:
         hypfs_diag_exit();
-fail_debugfs_remove:
-        debugfs_remove(hypfs_dbfs_dir);
-
+fail_dbfs_exit:
+        hypfs_dbfs_exit();
         pr_err("Initialization of hypfs failed with rc=%i\n", rc);
         return rc;
 }
@@ -510,7 +506,7 @@ static void __exit hypfs_exit(void)
 {
         hypfs_diag_exit();
         hypfs_vm_exit();
-        debugfs_remove(hypfs_dbfs_dir);
+        hypfs_dbfs_exit();
         unregister_filesystem(&hypfs_type);
         kobject_put(s390_kobj);
 }