https://github.com/torvalds/linux
Revision de66b380977eb9daa925aeb21756a9b00f700e45 authored by Javier Martinez Canillas on 30 July 2015, 16:18:43 UTC, committed by Guenter Roeck on 05 August 2015, 15:31:59 UTC
The I2C core always reports the MODALIAS uevent as "i2c:<client name"
regardless if the driver was matched using the I2C id_table or the
of_match_table. So technically there's no need for a driver to export
the OF table since currently it's not used.

In fact, the I2C device ID table is mandatory for I2C drivers since
a i2c_device_id is passed to the driver's probe function even if the
I2C core used the OF table to match the driver.

And since the I2C core uses different tables, OF-only drivers needs to
have duplicated data that has to be kept in sync and also the dev node
compatible manufacturer prefix is stripped when reporting the MODALIAS.

To avoid the above, the I2C core behavior may be changed in the future
to not require an I2C device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table to prevent
breaking module autoloading if that happens.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
1 parent 1252be9
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Tip revision: de66b380977eb9daa925aeb21756a9b00f700e45 authored by Javier Martinez Canillas on 30 July 2015, 16:18:43 UTC
hwmon: (g762) Export OF module alias information
Tip revision: de66b38
statfs.c
#include <linux/syscalls.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/uaccess.h>
#include "internal.h"

static int flags_by_mnt(int mnt_flags)
{
	int flags = 0;

	if (mnt_flags & MNT_READONLY)
		flags |= ST_RDONLY;
	if (mnt_flags & MNT_NOSUID)
		flags |= ST_NOSUID;
	if (mnt_flags & MNT_NODEV)
		flags |= ST_NODEV;
	if (mnt_flags & MNT_NOEXEC)
		flags |= ST_NOEXEC;
	if (mnt_flags & MNT_NOATIME)
		flags |= ST_NOATIME;
	if (mnt_flags & MNT_NODIRATIME)
		flags |= ST_NODIRATIME;
	if (mnt_flags & MNT_RELATIME)
		flags |= ST_RELATIME;
	return flags;
}

static int flags_by_sb(int s_flags)
{
	int flags = 0;
	if (s_flags & MS_SYNCHRONOUS)
		flags |= ST_SYNCHRONOUS;
	if (s_flags & MS_MANDLOCK)
		flags |= ST_MANDLOCK;
	return flags;
}

static int calculate_f_flags(struct vfsmount *mnt)
{
	return ST_VALID | flags_by_mnt(mnt->mnt_flags) |
		flags_by_sb(mnt->mnt_sb->s_flags);
}

static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
{
	int retval;

	if (!dentry->d_sb->s_op->statfs)
		return -ENOSYS;

	memset(buf, 0, sizeof(*buf));
	retval = security_sb_statfs(dentry);
	if (retval)
		return retval;
	retval = dentry->d_sb->s_op->statfs(dentry, buf);
	if (retval == 0 && buf->f_frsize == 0)
		buf->f_frsize = buf->f_bsize;
	return retval;
}

int vfs_statfs(struct path *path, struct kstatfs *buf)
{
	int error;

	error = statfs_by_dentry(path->dentry, buf);
	if (!error)
		buf->f_flags = calculate_f_flags(path->mnt);
	return error;
}
EXPORT_SYMBOL(vfs_statfs);

int user_statfs(const char __user *pathname, struct kstatfs *st)
{
	struct path path;
	int error;
	unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT;
retry:
	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
	if (!error) {
		error = vfs_statfs(&path, st);
		path_put(&path);
		if (retry_estale(error, lookup_flags)) {
			lookup_flags |= LOOKUP_REVAL;
			goto retry;
		}
	}
	return error;
}

int fd_statfs(int fd, struct kstatfs *st)
{
	struct fd f = fdget_raw(fd);
	int error = -EBADF;
	if (f.file) {
		error = vfs_statfs(&f.file->f_path, st);
		fdput(f);
	}
	return error;
}

static int do_statfs_native(struct kstatfs *st, struct statfs __user *p)
{
	struct statfs buf;

	if (sizeof(buf) == sizeof(*st))
		memcpy(&buf, st, sizeof(*st));
	else {
		if (sizeof buf.f_blocks == 4) {
			if ((st->f_blocks | st->f_bfree | st->f_bavail |
			     st->f_bsize | st->f_frsize) &
			    0xffffffff00000000ULL)
				return -EOVERFLOW;
			/*
			 * f_files and f_ffree may be -1; it's okay to stuff
			 * that into 32 bits
			 */
			if (st->f_files != -1 &&
			    (st->f_files & 0xffffffff00000000ULL))
				return -EOVERFLOW;
			if (st->f_ffree != -1 &&
			    (st->f_ffree & 0xffffffff00000000ULL))
				return -EOVERFLOW;
		}

		buf.f_type = st->f_type;
		buf.f_bsize = st->f_bsize;
		buf.f_blocks = st->f_blocks;
		buf.f_bfree = st->f_bfree;
		buf.f_bavail = st->f_bavail;
		buf.f_files = st->f_files;
		buf.f_ffree = st->f_ffree;
		buf.f_fsid = st->f_fsid;
		buf.f_namelen = st->f_namelen;
		buf.f_frsize = st->f_frsize;
		buf.f_flags = st->f_flags;
		memset(buf.f_spare, 0, sizeof(buf.f_spare));
	}
	if (copy_to_user(p, &buf, sizeof(buf)))
		return -EFAULT;
	return 0;
}

static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p)
{
	struct statfs64 buf;
	if (sizeof(buf) == sizeof(*st))
		memcpy(&buf, st, sizeof(*st));
	else {
		buf.f_type = st->f_type;
		buf.f_bsize = st->f_bsize;
		buf.f_blocks = st->f_blocks;
		buf.f_bfree = st->f_bfree;
		buf.f_bavail = st->f_bavail;
		buf.f_files = st->f_files;
		buf.f_ffree = st->f_ffree;
		buf.f_fsid = st->f_fsid;
		buf.f_namelen = st->f_namelen;
		buf.f_frsize = st->f_frsize;
		buf.f_flags = st->f_flags;
		memset(buf.f_spare, 0, sizeof(buf.f_spare));
	}
	if (copy_to_user(p, &buf, sizeof(buf)))
		return -EFAULT;
	return 0;
}

SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
{
	struct kstatfs st;
	int error = user_statfs(pathname, &st);
	if (!error)
		error = do_statfs_native(&st, buf);
	return error;
}

SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
{
	struct kstatfs st;
	int error;
	if (sz != sizeof(*buf))
		return -EINVAL;
	error = user_statfs(pathname, &st);
	if (!error)
		error = do_statfs64(&st, buf);
	return error;
}

SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
{
	struct kstatfs st;
	int error = fd_statfs(fd, &st);
	if (!error)
		error = do_statfs_native(&st, buf);
	return error;
}

SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
{
	struct kstatfs st;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = fd_statfs(fd, &st);
	if (!error)
		error = do_statfs64(&st, buf);
	return error;
}

int vfs_ustat(dev_t dev, struct kstatfs *sbuf)
{
	struct super_block *s = user_get_super(dev);
	int err;
	if (!s)
		return -EINVAL;

	err = statfs_by_dentry(s->s_root, sbuf);
	drop_super(s);
	return err;
}

SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
{
	struct ustat tmp;
	struct kstatfs sbuf;
	int err = vfs_ustat(new_decode_dev(dev), &sbuf);
	if (err)
		return err;

	memset(&tmp,0,sizeof(struct ustat));
	tmp.f_tfree = sbuf.f_bfree;
	tmp.f_tinode = sbuf.f_ffree;

	return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
}
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