@@ -27,6 +27,7 @@
*/
#include <linux/debugfs.h>
+#include <linux/drmfs.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
@@ -200,6 +200,15 @@ config HUGETLBFS
config HUGETLB_PAGE
def_bool HUGETLBFS
+config DRMFS
+ bool "Drmfs file system support"
+ depends on DRM
+ help
+ Drmfs is a pseudo file system for drm subsystem output data.
+
+ drmfs is a filesystem to hold miscellaneous output data from drm
+ subsystems.
+
config ARCH_HAS_GIGANTIC_PAGE
bool
@@ -120,6 +120,7 @@ obj-$(CONFIG_BEFS_FS) += befs/
obj-$(CONFIG_HOSTFS) += hostfs/
obj-$(CONFIG_CACHEFILES) += cachefiles/
obj-$(CONFIG_DEBUG_FS) += debugfs/
+obj-$(CONFIG_DRMFS) += drmfs/
obj-$(CONFIG_TRACING) += tracefs/
obj-$(CONFIG_OCFS2_FS) += ocfs2/
obj-$(CONFIG_BTRFS_FS) += btrfs/
new file mode 100644
@@ -0,0 +1,3 @@
+drmfs-objs := inode.o
+
+obj-$(CONFIG_DRMFS) += drmfs.o
new file mode 100644
@@ -0,0 +1,561 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Swati Dhingra <swati.dhingra@intel.com>
+ * Sourab Gupta <sourab.gupta@intel.com>
+ * Akash Goel <akash.goel@intel.com>
+ */
+
+/*
+ * drmfs is the filesystem used for output of drm subsystem data
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/kobject.h>
+#include <linux/namei.h>
+#include <linux/drmfs.h>
+#include <linux/fsnotify.h>
+#include <linux/seq_file.h>
+#include <linux/parser.h>
+#include <linux/magic.h>
+#include <linux/slab.h>
+
+#define DRMFS_DEFAULT_MODE 0700
+
+static struct vfsmount *drmfs_mount;
+static int drmfs_mount_count;
+static bool drmfs_registered;
+
+static ssize_t default_read_file(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static ssize_t default_write_file(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return count;
+}
+
+static const struct file_operations drmfs_default_file_operations = {
+ .read = default_read_file,
+ .write = default_write_file,
+ .open = simple_open,
+ .llseek = noop_llseek,
+};
+
+static struct inode *drmfs_get_inode(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ }
+ return inode;
+}
+
+struct drmfs_mount_opts {
+ kuid_t uid;
+ kgid_t gid;
+ umode_t mode;
+};
+
+enum {
+ Opt_uid,
+ Opt_gid,
+ Opt_mode,
+ Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_uid, "uid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_mode, "mode=%o"},
+ {Opt_err, NULL}
+};
+
+struct drmfs_fs_info {
+ struct drmfs_mount_opts mount_opts;
+};
+
+static int drmfs_parse_options(char *data, struct drmfs_mount_opts *opts)
+{
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ int token;
+ kuid_t uid;
+ kgid_t gid;
+ char *p;
+
+ opts->mode = DRMFS_DEFAULT_MODE;
+
+ while ((p = strsep(&data, ",")) != NULL) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_uid:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ uid = make_kuid(current_user_ns(), option);
+ if (!uid_valid(uid))
+ return -EINVAL;
+ opts->uid = uid;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(gid))
+ return -EINVAL;
+ opts->gid = gid;
+ break;
+ case Opt_mode:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->mode = option & S_IALLUGO;
+ break;
+ /*
+ * We might like to report bad mount options here
+ */
+ }
+ }
+
+ return 0;
+}
+
+static int drmfs_apply_options(struct super_block *sb)
+{
+ struct drmfs_fs_info *fsi = sb->s_fs_info;
+ struct inode *inode = sb->s_root->d_inode;
+ struct drmfs_mount_opts *opts = &fsi->mount_opts;
+
+ inode->i_mode &= ~S_IALLUGO;
+ inode->i_mode |= opts->mode;
+
+ inode->i_uid = opts->uid;
+ inode->i_gid = opts->gid;
+
+ return 0;
+}
+
+static int drmfs_remount(struct super_block *sb, int *flags, char *data)
+{
+ int err;
+ struct drmfs_fs_info *fsi = sb->s_fs_info;
+
+ sync_filesystem(sb);
+ err = drmfs_parse_options(data, &fsi->mount_opts);
+ if (err)
+ goto fail;
+
+ drmfs_apply_options(sb);
+
+fail:
+ return err;
+}
+
+static int drmfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct drmfs_fs_info *fsi = root->d_sb->s_fs_info;
+ struct drmfs_mount_opts *opts = &fsi->mount_opts;
+
+ if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, opts->uid));
+ if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, opts->gid));
+ if (opts->mode != DRMFS_DEFAULT_MODE)
+ seq_printf(m, ",mode=%o", opts->mode);
+
+ return 0;
+}
+
+static const struct super_operations drmfs_super_operations = {
+ .statfs = simple_statfs,
+ .remount_fs = drmfs_remount,
+ .show_options = drmfs_show_options,
+};
+
+static int drm_fill_super(struct super_block *sb, void *data, int silent)
+{
+ static struct tree_descr drm_files[] = { {""} };
+ struct drmfs_fs_info *fsi;
+ int err;
+
+ save_mount_options(sb, data);
+
+ fsi = kzalloc(sizeof(struct drmfs_fs_info), GFP_KERNEL);
+ sb->s_fs_info = fsi;
+ if (!fsi) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ err = drmfs_parse_options(data, &fsi->mount_opts);
+ if (err)
+ goto fail;
+
+ err = simple_fill_super(sb, DRMFS_MAGIC, drm_files);
+ if (err)
+ goto fail;
+
+ sb->s_op = &drmfs_super_operations;
+
+ drmfs_apply_options(sb);
+
+ return 0;
+
+fail:
+ kfree(fsi);
+ sb->s_fs_info = NULL;
+ return err;
+}
+
+static struct dentry *drm_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ return mount_single(fs_type, flags, data, drm_fill_super);
+}
+
+static struct file_system_type drm_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "drmfs",
+ .mount = drm_mount,
+ .kill_sb = kill_litter_super,
+};
+MODULE_ALIAS_FS("drmfs");
+
+static struct dentry *start_creating(const char *name, struct dentry *parent)
+{
+ struct dentry *dentry;
+ int error;
+
+ pr_debug("drmfs: creating file '%s'\n", name);
+
+ error = simple_pin_fs(&drm_fs_type, &drmfs_mount,
+ &drmfs_mount_count);
+ if (error)
+ return ERR_PTR(error);
+
+ /* If the parent is not specified, we create it in the root.
+ * We need the root dentry to do this, which is in the super
+ * block. A pointer to that is in the struct vfsmount that we
+ * have around.
+ */
+ if (!parent)
+ parent = drmfs_mount->mnt_root;
+
+ inode_lock(parent->d_inode);
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (!IS_ERR(dentry) && dentry->d_inode) {
+ dput(dentry);
+ dentry = ERR_PTR(-EEXIST);
+ }
+
+ if (IS_ERR(dentry)) {
+ inode_unlock(parent->d_inode);
+ simple_release_fs(&drmfs_mount, &drmfs_mount_count);
+ }
+
+ return dentry;
+}
+
+static struct dentry *failed_creating(struct dentry *dentry)
+{
+ inode_unlock(dentry->d_parent->d_inode);
+ dput(dentry);
+ simple_release_fs(&drmfs_mount, &drmfs_mount_count);
+ return NULL;
+}
+
+static struct dentry *end_creating(struct dentry *dentry)
+{
+ inode_unlock(dentry->d_parent->d_inode);
+ return dentry;
+}
+
+/**
+ * drmfs_create_file - create a file in the drmfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the drmfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ *
+ * This is the basic "create a file" function for drmfs. It allows for a
+ * wide range of flexibility in creating a file, or a directory (if you want
+ * to create a directory, the drmfs_create_dir() function is
+ * recommended to be used instead.)
+ *
+ * This function will return a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the drmfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.) If an error occurs, %NULL will be returned.
+ *
+ */
+struct dentry *drmfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+
+ if (!(mode & S_IFMT))
+ mode |= S_IFREG;
+
+ if (WARN_ON(!S_ISREG(mode)))
+ return NULL;
+
+ dentry = start_creating(name, parent);
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = drmfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = mode;
+ inode->i_fop = fops ? fops : &drmfs_default_file_operations;
+ inode->i_private = data;
+ d_instantiate(dentry, inode);
+ fsnotify_create(dentry->d_parent->d_inode, dentry);
+ return end_creating(dentry);
+}
+EXPORT_SYMBOL(drmfs_create_file);
+
+static struct dentry *__create_dir(const char *name, struct dentry *parent,
+ const struct inode_operations *ops)
+{
+ struct dentry *dentry = start_creating(name, parent);
+ struct inode *inode;
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = drmfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ inode->i_op = ops;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ d_instantiate(dentry, inode);
+ inc_nlink(dentry->d_parent->d_inode);
+ fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
+ return end_creating(dentry);
+}
+
+/**
+ * drmfs_create_dir - create a directory in the drmfs filesystem
+ * @name: a pointer to a string containing the name of the directory to
+ * create.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * directory will be created in the root of the drmfs filesystem.
+ *
+ * This function creates a directory in drmfs with the given name.
+ *
+ * This function will return a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the drmfs_remove() function when the file is
+ * to be removed. If an error occurs, %NULL will be returned.
+ *
+ */
+struct dentry *drmfs_create_dir(const char *name, struct dentry *parent)
+{
+ return __create_dir(name, parent, &simple_dir_inode_operations);
+}
+EXPORT_SYMBOL(drmfs_create_dir);
+
+static int __drmfs_remove(struct dentry *dentry, struct dentry *parent)
+{
+ int ret = 0;
+
+ if (simple_positive(dentry)) {
+ if (dentry->d_inode) {
+ dget(dentry);
+ switch (dentry->d_inode->i_mode & S_IFMT) {
+ case S_IFDIR:
+ ret = simple_rmdir(parent->d_inode, dentry);
+ break;
+ default:
+ simple_unlink(parent->d_inode, dentry);
+ break;
+ }
+ if (!ret)
+ d_delete(dentry);
+ dput(dentry);
+ }
+ }
+ return ret;
+}
+
+
+/**
+ * drmfs_remove - removes a file or directory from the drmfs filesystem
+ * @dentry: a pointer to a the dentry of the file or directory to be
+ * removed.
+ *
+ * This function removes a file or directory in drmfs that was previously
+ * created with a call to another drmfs function (like
+ * drmfs_create_file() or variants thereof.)
+ */
+void drmfs_remove(struct dentry *dentry)
+{
+ struct dentry *parent;
+ int ret;
+
+ if (IS_ERR_OR_NULL(dentry))
+ return;
+
+ parent = dentry->d_parent;
+ inode_lock(parent->d_inode);
+ ret = __drmfs_remove(dentry, parent);
+ inode_unlock(parent->d_inode);
+ if (!ret)
+ simple_release_fs(&drmfs_mount, &drmfs_mount_count);
+}
+EXPORT_SYMBOL(drmfs_remove);
+
+/**
+ * drmfs_remove_recursive - recursively removes a directory
+ * @dentry: a pointer to a the dentry of the directory to be removed.
+ *
+ * This function recursively removes a directory tree in drmfs that
+ * was previously created with a call to another drmfs function
+ * (like drmfs_create_file() or variants thereof.)
+ */
+void drmfs_remove_recursive(struct dentry *dentry)
+{
+ struct dentry *child, *parent;
+
+ if (IS_ERR_OR_NULL(dentry))
+ return;
+
+ parent = dentry;
+ down:
+ inode_lock(parent->d_inode);
+ loop:
+ /*
+ * The parent->d_subdirs is protected by the d_lock. Outside that
+ * lock, the child can be unlinked and set to be freed which can
+ * use the d_u.d_child as the rcu head and corrupt this list.
+ */
+ spin_lock(&parent->d_lock);
+ list_for_each_entry(child, &parent->d_subdirs, d_child) {
+ if (!simple_positive(child))
+ continue;
+
+ /* perhaps simple_empty(child) makes more sense */
+ if (!list_empty(&child->d_subdirs)) {
+ spin_unlock(&parent->d_lock);
+ inode_unlock(parent->d_inode);
+ parent = child;
+ goto down;
+ }
+
+ spin_unlock(&parent->d_lock);
+
+ if (!__drmfs_remove(child, parent))
+ simple_release_fs(&drmfs_mount, &drmfs_mount_count);
+
+ /*
+ * The parent->d_lock protects against child from unlinking
+ * from d_subdirs. When releasing the parent->d_lock we can
+ * no longer trust that the next pointer is valid.
+ * Restart the loop. We'll skip this one with the
+ * simple_positive() check.
+ */
+ goto loop;
+ }
+ spin_unlock(&parent->d_lock);
+
+ inode_unlock(parent->d_inode);
+ child = parent;
+ parent = parent->d_parent;
+ inode_lock(parent->d_inode);
+
+ if (child != dentry)
+ /* go up */
+ goto loop;
+
+ if (!__drmfs_remove(child, parent))
+ simple_release_fs(&drmfs_mount, &drmfs_mount_count);
+ inode_unlock(parent->d_inode);
+}
+EXPORT_SYMBOL(drmfs_remove_recursive);
+
+/**
+ * drmfs_initialized - Tells whether drmfs has been registered
+ */
+bool drmfs_initialized(void)
+{
+ return drmfs_registered;
+}
+EXPORT_SYMBOL(drmfs_initialized);
+
+int drmfs_init(void)
+{
+ int retval;
+
+ retval = sysfs_create_mount_point(kernel_kobj, "drm");
+ if (retval)
+ return -EINVAL;
+
+ retval = register_filesystem(&drm_fs_type);
+ if (!retval)
+ drmfs_registered = true;
+
+ return retval;
+}
+EXPORT_SYMBOL(drmfs_init);
+
+int drmfs_fini(void)
+{
+ int retval;
+
+ retval = unregister_filesystem(&drm_fs_type);
+ if (retval)
+ return retval;
+
+ drmfs_registered = false;
+
+ sysfs_remove_mount_point(kernel_kobj, "drm");
+}
+EXPORT_SYMBOL(drmfs_fini);
new file mode 100644
@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Swati Dhingra <swati.dhingra@intel.com>
+ * Sourab Gupta <sourab.gupta@intel.com>
+ * Akash Goel <akash.goel@intel.com>
+ */
+
+#ifndef _DRMFS_H_
+#define _DRMFS_H_
+
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+
+#include <linux/types.h>
+
+struct file_operations;
+
+#ifdef CONFIG_DRMFS
+
+struct dentry *drmfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops);
+
+struct dentry *drmfs_create_dir(const char *name, struct dentry *parent);
+
+void drmfs_remove(struct dentry *dentry);
+void drmfs_remove_recursive(struct dentry *dentry);
+
+bool drmfs_initialized(void);
+int drmfs_init(void);
+int drmfs_fini(void);
+
+#endif /* CONFIG_DRMFS */
+
+#endif
@@ -61,6 +61,9 @@
#define STACK_END_MAGIC 0x57AC6E9D
#define TRACEFS_MAGIC 0x74726163
+#define DRMFS_MAGIC 0x84724143 /* some random number.
+ * Is there a better way?
+ */
#define V9FS_MAGIC 0x01021997