[Intel-gfx] [RFC 1/3] fs: Introduce drmfs pseudo filesystem interfaces
sourab gupta
sourab.gupta at intel.com
Fri Dec 2 08:27:21 UTC 2016
On Thu, 2016-12-01 at 23:53 -0800, Daniel Vetter wrote:
> On Thu, Dec 01, 2016 at 01:44:15PM +0530, swati.dhingra at intel.com wrote:
> > From: Swati Dhingra <swati.dhingra at intel.com>
> >
> > The patch introduces a new pseudo filesystem type, named 'drmfs' which is
> > intended to house the files for the data generated by drm subsystem that
> > cannot be accommodated by any of the existing filesystems.
> > The filesystem is modelled on the lines of existing pseudo-filesystems such
> > as debugfs/tracefs, and borrows ideas from their implementation.
> > This filesystem will be appearing at sys/kernel/drm.
> >
> > A new config 'CONFIG_DRMFS' is introduced to enable/disable the filesystem,
> > which is dependent on CONFIG_DRM.
> > The filesystem will not be registered standalone during kernel init time,
> > instead it is intended to be initialized/registered during drm initialization.
> >
> > The intent for introduction of the filesystem is to act as a location to hold
> > various kinds of data output from Linux DRM subsystems, which can't really fit
> > anywhere else into the existing filesystems such as debugfs/sysfs etc. All these
> > filesystems have their own constraints and are intended to output a particular
> > type of data such as attributes and small debug parameter data. Due to these
> > constraints, there is a need for a new pseudo filesytem, customizable to DRM
> > specific requirements and catering to the needs to DRM subsystem components
> >
> > Signed-off-by: Sourab Gupta <sourab.gupta at intel.com>
> > Signed-off-by: Swati Dhingra <swati.dhingra at intel.com>
>
> I thought review feedback was to put that into drm, not under fs/? Also,
> needs proper ccing.
> -Daniel
>
Hi Daniel,
We'll remove it from fs and add under drm/ in the next version of
series. Sorry, forgot to add dri-devel, will add it when we send next
version.
> > ---
> > drivers/gpu/drm/drm_drv.c | 1 +
> > fs/Kconfig | 9 +
> > fs/Makefile | 1 +
> > fs/drmfs/Makefile | 3 +
> > fs/drmfs/inode.c | 561 +++++++++++++++++++++++++++++++++++++++++++++
> > include/linux/drmfs.h | 56 +++++
> > include/uapi/linux/magic.h | 3 +
> > 7 files changed, 634 insertions(+)
> > create mode 100644 fs/drmfs/Makefile
> > create mode 100644 fs/drmfs/inode.c
> > create mode 100644 include/linux/drmfs.h
> >
> > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> > index 6dbb986..84fcfcb 100644
> > --- a/drivers/gpu/drm/drm_drv.c
> > +++ b/drivers/gpu/drm/drm_drv.c
> > @@ -27,6 +27,7 @@
> > */
> >
> > #include <linux/debugfs.h>
> > +#include <linux/drmfs.h>
> > #include <linux/fs.h>
> > #include <linux/module.h>
> > #include <linux/moduleparam.h>
> > diff --git a/fs/Kconfig b/fs/Kconfig
> > index 4bd03a2..7d0ac20 100644
> > --- a/fs/Kconfig
> > +++ b/fs/Kconfig
> > @@ -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
> >
> > diff --git a/fs/Makefile b/fs/Makefile
> > index ed2b632..b34a96e 100644
> > --- a/fs/Makefile
> > +++ b/fs/Makefile
> > @@ -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/
> > diff --git a/fs/drmfs/Makefile b/fs/drmfs/Makefile
> > new file mode 100644
> > index 0000000..ac87e497
> > --- /dev/null
> > +++ b/fs/drmfs/Makefile
> > @@ -0,0 +1,3 @@
> > +drmfs-objs := inode.o
> > +
> > +obj-$(CONFIG_DRMFS) += drmfs.o
> > diff --git a/fs/drmfs/inode.c b/fs/drmfs/inode.c
> > new file mode 100644
> > index 0000000..9220705
> > --- /dev/null
> > +++ b/fs/drmfs/inode.c
> > @@ -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 at intel.com>
> > + * Sourab Gupta <sourab.gupta at intel.com>
> > + * Akash Goel <akash.goel at 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);
> > diff --git a/include/linux/drmfs.h b/include/linux/drmfs.h
> > new file mode 100644
> > index 0000000..3091480
> > --- /dev/null
> > +++ b/include/linux/drmfs.h
> > @@ -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 at intel.com>
> > + * Sourab Gupta <sourab.gupta at intel.com>
> > + * Akash Goel <akash.goel at 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
> > diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h
> > index 9bd5594..ef01eb7 100644
> > --- a/include/uapi/linux/magic.h
> > +++ b/include/uapi/linux/magic.h
> > @@ -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
> >
> > --
> > 2.7.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
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