drm/panthor: Don't add write fences to the shared BOs

[drm/drm-misc.git] / fs / ioctl.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/ioctl.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/syscalls.h>
#include <linux/mm.h>
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h>
#include <linux/falloc.h>
#include <linux/sched/signal.h>
#include <linux/fiemap.h>
#include <linux/mount.h>
#include <linux/fscrypt.h>
#include <linux/fileattr.h>

#include "internal.h"

#include <asm/ioctls.h>

/* So that the fiemap access checks can't overflow on 32 bit machines. */
#define FIEMAP_MAX_EXTENTS      (UINT_MAX / sizeof(struct fiemap_extent))

/**
 * vfs_ioctl - call filesystem specific ioctl methods
 * @filp:       open file to invoke ioctl method on
 * @cmd:        ioctl command to execute
 * @arg:        command-specific argument for ioctl
 *
 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
 * returns -ENOTTY.
 *
 * Returns 0 on success, -errno on error.
 */
long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
        int error = -ENOTTY;

        if (!filp->f_op->unlocked_ioctl)
                goto out;

        error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
        if (error == -ENOIOCTLCMD)
                error = -ENOTTY;
 out:
        return error;
}
EXPORT_SYMBOL(vfs_ioctl);

static int ioctl_fibmap(struct file *filp, int __user *p)
{
        struct inode *inode = file_inode(filp);
        struct super_block *sb = inode->i_sb;
        int error, ur_block;
        sector_t block;

        if (!capable(CAP_SYS_RAWIO))
                return -EPERM;

        error = get_user(ur_block, p);
        if (error)
                return error;

        if (ur_block < 0)
                return -EINVAL;

        block = ur_block;
        error = bmap(inode, &block);

        if (block > INT_MAX) {
                error = -ERANGE;
                pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
                                    current->comm, task_pid_nr(current),
                                    sb->s_id, filp);
        }

        if (error)
                ur_block = 0;
        else
                ur_block = block;

        if (put_user(ur_block, p))
                error = -EFAULT;

        return error;
}

/**
 * fiemap_fill_next_extent - Fiemap helper function
 * @fieinfo:    Fiemap context passed into ->fiemap
 * @logical:    Extent logical start offset, in bytes
 * @phys:       Extent physical start offset, in bytes
 * @len:        Extent length, in bytes
 * @flags:      FIEMAP_EXTENT flags that describe this extent
 *
 * Called from file system ->fiemap callback. Will populate extent
 * info as passed in via arguments and copy to user memory. On
 * success, extent count on fieinfo is incremented.
 *
 * Returns 0 on success, -errno on error, 1 if this was the last
 * extent that will fit in user array.
 */
int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
                            u64 phys, u64 len, u32 flags)
{
        struct fiemap_extent extent;
        struct fiemap_extent __user *dest = fieinfo->fi_extents_start;

        /* only count the extents */
        if (fieinfo->fi_extents_max == 0) {
                fieinfo->fi_extents_mapped++;
                return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
        }

        if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
                return 1;

#define SET_UNKNOWN_FLAGS       (FIEMAP_EXTENT_DELALLOC)
#define SET_NO_UNMOUNTED_IO_FLAGS       (FIEMAP_EXTENT_DATA_ENCRYPTED)
#define SET_NOT_ALIGNED_FLAGS   (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)

        if (flags & SET_UNKNOWN_FLAGS)
                flags |= FIEMAP_EXTENT_UNKNOWN;
        if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
                flags |= FIEMAP_EXTENT_ENCODED;
        if (flags & SET_NOT_ALIGNED_FLAGS)
                flags |= FIEMAP_EXTENT_NOT_ALIGNED;

        memset(&extent, 0, sizeof(extent));
        extent.fe_logical = logical;
        extent.fe_physical = phys;
        extent.fe_length = len;
        extent.fe_flags = flags;

        dest += fieinfo->fi_extents_mapped;
        if (copy_to_user(dest, &extent, sizeof(extent)))
                return -EFAULT;

        fieinfo->fi_extents_mapped++;
        if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
                return 1;
        return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
}
EXPORT_SYMBOL(fiemap_fill_next_extent);

/**
 * fiemap_prep - check validity of requested flags for fiemap
 * @inode:      Inode to operate on
 * @fieinfo:    Fiemap context passed into ->fiemap
 * @start:      Start of the mapped range
 * @len:        Length of the mapped range, can be truncated by this function.
 * @supported_flags:    Set of fiemap flags that the file system understands
 *
 * This function must be called from each ->fiemap instance to validate the
 * fiemap request against the file system parameters.
 *
 * Returns 0 on success, or a negative error on failure.
 */
int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
                u64 start, u64 *len, u32 supported_flags)
{
        u64 maxbytes = inode->i_sb->s_maxbytes;
        u32 incompat_flags;
        int ret = 0;

        if (*len == 0)
                return -EINVAL;
        if (start >= maxbytes)
                return -EFBIG;

        /*
         * Shrink request scope to what the fs can actually handle.
         */
        if (*len > maxbytes || (maxbytes - *len) < start)
                *len = maxbytes - start;

        supported_flags |= FIEMAP_FLAG_SYNC;
        supported_flags &= FIEMAP_FLAGS_COMPAT;
        incompat_flags = fieinfo->fi_flags & ~supported_flags;
        if (incompat_flags) {
                fieinfo->fi_flags = incompat_flags;
                return -EBADR;
        }

        if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
                ret = filemap_write_and_wait(inode->i_mapping);
        return ret;
}
EXPORT_SYMBOL(fiemap_prep);

static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
{
        struct fiemap fiemap;
        struct fiemap_extent_info fieinfo = { 0, };
        struct inode *inode = file_inode(filp);
        int error;

        if (!inode->i_op->fiemap)
                return -EOPNOTSUPP;

        if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
                return -EFAULT;

        if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
                return -EINVAL;

        fieinfo.fi_flags = fiemap.fm_flags;
        fieinfo.fi_extents_max = fiemap.fm_extent_count;
        fieinfo.fi_extents_start = ufiemap->fm_extents;

        error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
                        fiemap.fm_length);

        fiemap.fm_flags = fieinfo.fi_flags;
        fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
        if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
                error = -EFAULT;

        return error;
}

static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
                             u64 off, u64 olen, u64 destoff)
{
        struct fd src_file = fdget(srcfd);
        loff_t cloned;
        int ret;

        if (!fd_file(src_file))
                return -EBADF;
        cloned = vfs_clone_file_range(fd_file(src_file), off, dst_file, destoff,
                                      olen, 0);
        if (cloned < 0)
                ret = cloned;
        else if (olen && cloned != olen)
                ret = -EINVAL;
        else
                ret = 0;
        fdput(src_file);
        return ret;
}

static long ioctl_file_clone_range(struct file *file,
                                   struct file_clone_range __user *argp)
{
        struct file_clone_range args;

        if (copy_from_user(&args, argp, sizeof(args)))
                return -EFAULT;
        return ioctl_file_clone(file, args.src_fd, args.src_offset,
                                args.src_length, args.dest_offset);
}

/*
 * This provides compatibility with legacy XFS pre-allocation ioctls
 * which predate the fallocate syscall.
 *
 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
 * are used here, rest are ignored.
 */
static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
{
        struct inode *inode = file_inode(filp);
        struct space_resv sr;

        if (copy_from_user(&sr, argp, sizeof(sr)))
                return -EFAULT;

        switch (sr.l_whence) {
        case SEEK_SET:
                break;
        case SEEK_CUR:
                sr.l_start += filp->f_pos;
                break;
        case SEEK_END:
                sr.l_start += i_size_read(inode);
                break;
        default:
                return -EINVAL;
        }

        return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
                        sr.l_len);
}

/* on ia32 l_start is on a 32-bit boundary */
#if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
/* just account for different alignment */
static int compat_ioctl_preallocate(struct file *file, int mode,
                                    struct space_resv_32 __user *argp)
{
        struct inode *inode = file_inode(file);
        struct space_resv_32 sr;

        if (copy_from_user(&sr, argp, sizeof(sr)))
                return -EFAULT;

        switch (sr.l_whence) {
        case SEEK_SET:
                break;
        case SEEK_CUR:
                sr.l_start += file->f_pos;
                break;
        case SEEK_END:
                sr.l_start += i_size_read(inode);
                break;
        default:
                return -EINVAL;
        }

        return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
}
#endif

static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
{
        switch (cmd) {
        case FIBMAP:
                return ioctl_fibmap(filp, p);
        case FS_IOC_RESVSP:
        case FS_IOC_RESVSP64:
                return ioctl_preallocate(filp, 0, p);
        case FS_IOC_UNRESVSP:
        case FS_IOC_UNRESVSP64:
                return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
        case FS_IOC_ZERO_RANGE:
                return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
        }

        return -ENOIOCTLCMD;
}

static int ioctl_fionbio(struct file *filp, int __user *argp)
{
        unsigned int flag;
        int on, error;

        error = get_user(on, argp);
        if (error)
                return error;
        flag = O_NONBLOCK;
#ifdef __sparc__
        /* SunOS compatibility item. */
        if (O_NONBLOCK != O_NDELAY)
                flag |= O_NDELAY;
#endif
        spin_lock(&filp->f_lock);
        if (on)
                filp->f_flags |= flag;
        else
                filp->f_flags &= ~flag;
        spin_unlock(&filp->f_lock);
        return error;
}

static int ioctl_fioasync(unsigned int fd, struct file *filp,
                          int __user *argp)
{
        unsigned int flag;
        int on, error;

        error = get_user(on, argp);
        if (error)
                return error;
        flag = on ? FASYNC : 0;

        /* Did FASYNC state change ? */
        if ((flag ^ filp->f_flags) & FASYNC) {
                if (filp->f_op->fasync)
                        /* fasync() adjusts filp->f_flags */
                        error = filp->f_op->fasync(fd, filp, on);
                else
                        error = -ENOTTY;
        }
        return error < 0 ? error : 0;
}

static int ioctl_fsfreeze(struct file *filp)
{
        struct super_block *sb = file_inode(filp)->i_sb;

        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
                return -EPERM;

        /* If filesystem doesn't support freeze feature, return. */
        if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
                return -EOPNOTSUPP;

        /* Freeze */
        if (sb->s_op->freeze_super)
                return sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE);
        return freeze_super(sb, FREEZE_HOLDER_USERSPACE);
}

static int ioctl_fsthaw(struct file *filp)
{
        struct super_block *sb = file_inode(filp)->i_sb;

        if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
                return -EPERM;

        /* Thaw */
        if (sb->s_op->thaw_super)
                return sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE);
        return thaw_super(sb, FREEZE_HOLDER_USERSPACE);
}

static int ioctl_file_dedupe_range(struct file *file,
                                   struct file_dedupe_range __user *argp)
{
        struct file_dedupe_range *same = NULL;
        int ret;
        unsigned long size;
        u16 count;

        if (get_user(count, &argp->dest_count)) {
                ret = -EFAULT;
                goto out;
        }

        size = offsetof(struct file_dedupe_range, info[count]);
        if (size > PAGE_SIZE) {
                ret = -ENOMEM;
                goto out;
        }

        same = memdup_user(argp, size);
        if (IS_ERR(same)) {
                ret = PTR_ERR(same);
                same = NULL;
                goto out;
        }

        same->dest_count = count;
        ret = vfs_dedupe_file_range(file, same);
        if (ret)
                goto out;

        ret = copy_to_user(argp, same, size);
        if (ret)
                ret = -EFAULT;

out:
        kfree(same);
        return ret;
}

/**
 * fileattr_fill_xflags - initialize fileattr with xflags
 * @fa:         fileattr pointer
 * @xflags:     FS_XFLAG_* flags
 *
 * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags).  All
 * other fields are zeroed.
 */
void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
{
        memset(fa, 0, sizeof(*fa));
        fa->fsx_valid = true;
        fa->fsx_xflags = xflags;
        if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)
                fa->flags |= FS_IMMUTABLE_FL;
        if (fa->fsx_xflags & FS_XFLAG_APPEND)
                fa->flags |= FS_APPEND_FL;
        if (fa->fsx_xflags & FS_XFLAG_SYNC)
                fa->flags |= FS_SYNC_FL;
        if (fa->fsx_xflags & FS_XFLAG_NOATIME)
                fa->flags |= FS_NOATIME_FL;
        if (fa->fsx_xflags & FS_XFLAG_NODUMP)
                fa->flags |= FS_NODUMP_FL;
        if (fa->fsx_xflags & FS_XFLAG_DAX)
                fa->flags |= FS_DAX_FL;
        if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
                fa->flags |= FS_PROJINHERIT_FL;
}
EXPORT_SYMBOL(fileattr_fill_xflags);

/**
 * fileattr_fill_flags - initialize fileattr with flags
 * @fa:         fileattr pointer
 * @flags:      FS_*_FL flags
 *
 * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags).
 * All other fields are zeroed.
 */
void fileattr_fill_flags(struct fileattr *fa, u32 flags)
{
        memset(fa, 0, sizeof(*fa));
        fa->flags_valid = true;
        fa->flags = flags;
        if (fa->flags & FS_SYNC_FL)
                fa->fsx_xflags |= FS_XFLAG_SYNC;
        if (fa->flags & FS_IMMUTABLE_FL)
                fa->fsx_xflags |= FS_XFLAG_IMMUTABLE;
        if (fa->flags & FS_APPEND_FL)
                fa->fsx_xflags |= FS_XFLAG_APPEND;
        if (fa->flags & FS_NODUMP_FL)
                fa->fsx_xflags |= FS_XFLAG_NODUMP;
        if (fa->flags & FS_NOATIME_FL)
                fa->fsx_xflags |= FS_XFLAG_NOATIME;
        if (fa->flags & FS_DAX_FL)
                fa->fsx_xflags |= FS_XFLAG_DAX;
        if (fa->flags & FS_PROJINHERIT_FL)
                fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
}
EXPORT_SYMBOL(fileattr_fill_flags);

/**
 * vfs_fileattr_get - retrieve miscellaneous file attributes
 * @dentry:     the object to retrieve from
 * @fa:         fileattr pointer
 *
 * Call i_op->fileattr_get() callback, if exists.
 *
 * Return: 0 on success, or a negative error on failure.
 */
int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
{
        struct inode *inode = d_inode(dentry);

        if (!inode->i_op->fileattr_get)
                return -ENOIOCTLCMD;

        return inode->i_op->fileattr_get(dentry, fa);
}
EXPORT_SYMBOL(vfs_fileattr_get);

/**
 * copy_fsxattr_to_user - copy fsxattr to userspace.
 * @fa:         fileattr pointer
 * @ufa:        fsxattr user pointer
 *
 * Return: 0 on success, or -EFAULT on failure.
 */
int copy_fsxattr_to_user(const struct fileattr *fa, struct fsxattr __user *ufa)
{
        struct fsxattr xfa;

        memset(&xfa, 0, sizeof(xfa));
        xfa.fsx_xflags = fa->fsx_xflags;
        xfa.fsx_extsize = fa->fsx_extsize;
        xfa.fsx_nextents = fa->fsx_nextents;
        xfa.fsx_projid = fa->fsx_projid;
        xfa.fsx_cowextsize = fa->fsx_cowextsize;

        if (copy_to_user(ufa, &xfa, sizeof(xfa)))
                return -EFAULT;

        return 0;
}
EXPORT_SYMBOL(copy_fsxattr_to_user);

static int copy_fsxattr_from_user(struct fileattr *fa,
                                  struct fsxattr __user *ufa)
{
        struct fsxattr xfa;

        if (copy_from_user(&xfa, ufa, sizeof(xfa)))
                return -EFAULT;

        fileattr_fill_xflags(fa, xfa.fsx_xflags);
        fa->fsx_extsize = xfa.fsx_extsize;
        fa->fsx_nextents = xfa.fsx_nextents;
        fa->fsx_projid = xfa.fsx_projid;
        fa->fsx_cowextsize = xfa.fsx_cowextsize;

        return 0;
}

/*
 * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject
 * any invalid configurations.
 *
 * Note: must be called with inode lock held.
 */
static int fileattr_set_prepare(struct inode *inode,
                              const struct fileattr *old_ma,
                              struct fileattr *fa)
{
        int err;

        /*
         * The IMMUTABLE and APPEND_ONLY flags can only be changed by
         * the relevant capability.
         */
        if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) &&
            !capable(CAP_LINUX_IMMUTABLE))
                return -EPERM;

        err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags);
        if (err)
                return err;

        /*
         * Project Quota ID state is only allowed to change from within the init
         * namespace. Enforce that restriction only if we are trying to change
         * the quota ID state. Everything else is allowed in user namespaces.
         */
        if (current_user_ns() != &init_user_ns) {
                if (old_ma->fsx_projid != fa->fsx_projid)
                        return -EINVAL;
                if ((old_ma->fsx_xflags ^ fa->fsx_xflags) &
                                FS_XFLAG_PROJINHERIT)
                        return -EINVAL;
        } else {
                /*
                 * Caller is allowed to change the project ID. If it is being
                 * changed, make sure that the new value is valid.
                 */
                if (old_ma->fsx_projid != fa->fsx_projid &&
                    !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid)))
                        return -EINVAL;
        }

        /* Check extent size hints. */
        if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode))
                return -EINVAL;

        if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) &&
                        !S_ISDIR(inode->i_mode))
                return -EINVAL;

        if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
            !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
                return -EINVAL;

        /*
         * It is only valid to set the DAX flag on regular files and
         * directories on filesystems.
         */
        if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
            !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
                return -EINVAL;

        /* Extent size hints of zero turn off the flags. */
        if (fa->fsx_extsize == 0)
                fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);
        if (fa->fsx_cowextsize == 0)
                fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;

        return 0;
}

/**
 * vfs_fileattr_set - change miscellaneous file attributes
 * @idmap:      idmap of the mount
 * @dentry:     the object to change
 * @fa:         fileattr pointer
 *
 * After verifying permissions, call i_op->fileattr_set() callback, if
 * exists.
 *
 * Verifying attributes involves retrieving current attributes with
 * i_op->fileattr_get(), this also allows initializing attributes that have
 * not been set by the caller to current values.  Inode lock is held
 * thoughout to prevent racing with another instance.
 *
 * Return: 0 on success, or a negative error on failure.
 */
int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry,
                     struct fileattr *fa)
{
        struct inode *inode = d_inode(dentry);
        struct fileattr old_ma = {};
        int err;

        if (!inode->i_op->fileattr_set)
                return -ENOIOCTLCMD;

        if (!inode_owner_or_capable(idmap, inode))
                return -EPERM;

        inode_lock(inode);
        err = vfs_fileattr_get(dentry, &old_ma);
        if (!err) {
                /* initialize missing bits from old_ma */
                if (fa->flags_valid) {
                        fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON;
                        fa->fsx_extsize = old_ma.fsx_extsize;
                        fa->fsx_nextents = old_ma.fsx_nextents;
                        fa->fsx_projid = old_ma.fsx_projid;
                        fa->fsx_cowextsize = old_ma.fsx_cowextsize;
                } else {
                        fa->flags |= old_ma.flags & ~FS_COMMON_FL;
                }
                err = fileattr_set_prepare(inode, &old_ma, fa);
                if (!err)
                        err = inode->i_op->fileattr_set(idmap, dentry, fa);
        }
        inode_unlock(inode);

        return err;
}
EXPORT_SYMBOL(vfs_fileattr_set);

static int ioctl_getflags(struct file *file, unsigned int __user *argp)
{
        struct fileattr fa = { .flags_valid = true }; /* hint only */
        int err;

        err = vfs_fileattr_get(file->f_path.dentry, &fa);
        if (!err)
                err = put_user(fa.flags, argp);
        return err;
}

static int ioctl_setflags(struct file *file, unsigned int __user *argp)
{
        struct mnt_idmap *idmap = file_mnt_idmap(file);
        struct dentry *dentry = file->f_path.dentry;
        struct fileattr fa;
        unsigned int flags;
        int err;

        err = get_user(flags, argp);
        if (!err) {
                err = mnt_want_write_file(file);
                if (!err) {
                        fileattr_fill_flags(&fa, flags);
                        err = vfs_fileattr_set(idmap, dentry, &fa);
                        mnt_drop_write_file(file);
                }
        }
        return err;
}

static int ioctl_fsgetxattr(struct file *file, void __user *argp)
{
        struct fileattr fa = { .fsx_valid = true }; /* hint only */
        int err;

        err = vfs_fileattr_get(file->f_path.dentry, &fa);
        if (!err)
                err = copy_fsxattr_to_user(&fa, argp);

        return err;
}

static int ioctl_fssetxattr(struct file *file, void __user *argp)
{
        struct mnt_idmap *idmap = file_mnt_idmap(file);
        struct dentry *dentry = file->f_path.dentry;
        struct fileattr fa;
        int err;

        err = copy_fsxattr_from_user(&fa, argp);
        if (!err) {
                err = mnt_want_write_file(file);
                if (!err) {
                        err = vfs_fileattr_set(idmap, dentry, &fa);
                        mnt_drop_write_file(file);
                }
        }
        return err;
}

static int ioctl_getfsuuid(struct file *file, void __user *argp)
{
        struct super_block *sb = file_inode(file)->i_sb;
        struct fsuuid2 u = { .len = sb->s_uuid_len, };

        if (!sb->s_uuid_len)
                return -ENOTTY;

        memcpy(&u.uuid[0], &sb->s_uuid, sb->s_uuid_len);

        return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
}

static int ioctl_get_fs_sysfs_path(struct file *file, void __user *argp)
{
        struct super_block *sb = file_inode(file)->i_sb;

        if (!strlen(sb->s_sysfs_name))
                return -ENOTTY;

        struct fs_sysfs_path u = {};

        u.len = scnprintf(u.name, sizeof(u.name), "%s/%s", sb->s_type->name, sb->s_sysfs_name);

        return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
}

/*
 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
 *
 * When you add any new common ioctls to the switches above and below,
 * please ensure they have compatible arguments in compat mode.
 *
 * The LSM mailing list should also be notified of any command additions or
 * changes, as specific LSMs may be affected.
 */
static int do_vfs_ioctl(struct file *filp, unsigned int fd,
                        unsigned int cmd, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        struct inode *inode = file_inode(filp);

        switch (cmd) {
        case FIOCLEX:
                set_close_on_exec(fd, 1);
                return 0;

        case FIONCLEX:
                set_close_on_exec(fd, 0);
                return 0;

        case FIONBIO:
                return ioctl_fionbio(filp, argp);

        case FIOASYNC:
                return ioctl_fioasync(fd, filp, argp);

        case FIOQSIZE:
                if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
                    S_ISLNK(inode->i_mode)) {
                        loff_t res = inode_get_bytes(inode);
                        return copy_to_user(argp, &res, sizeof(res)) ?
                                            -EFAULT : 0;
                }

                return -ENOTTY;

        case FIFREEZE:
                return ioctl_fsfreeze(filp);

        case FITHAW:
                return ioctl_fsthaw(filp);

        case FS_IOC_FIEMAP:
                return ioctl_fiemap(filp, argp);

        case FIGETBSZ:
                /* anon_bdev filesystems may not have a block size */
                if (!inode->i_sb->s_blocksize)
                        return -EINVAL;

                return put_user(inode->i_sb->s_blocksize, (int __user *)argp);

        case FICLONE:
                return ioctl_file_clone(filp, arg, 0, 0, 0);

        case FICLONERANGE:
                return ioctl_file_clone_range(filp, argp);

        case FIDEDUPERANGE:
                return ioctl_file_dedupe_range(filp, argp);

        case FIONREAD:
                if (!S_ISREG(inode->i_mode))
                        return vfs_ioctl(filp, cmd, arg);

                return put_user(i_size_read(inode) - filp->f_pos,
                                (int __user *)argp);

        case FS_IOC_GETFLAGS:
                return ioctl_getflags(filp, argp);

        case FS_IOC_SETFLAGS:
                return ioctl_setflags(filp, argp);

        case FS_IOC_FSGETXATTR:
                return ioctl_fsgetxattr(filp, argp);

        case FS_IOC_FSSETXATTR:
                return ioctl_fssetxattr(filp, argp);

        case FS_IOC_GETFSUUID:
                return ioctl_getfsuuid(filp, argp);

        case FS_IOC_GETFSSYSFSPATH:
                return ioctl_get_fs_sysfs_path(filp, argp);

        default:
                if (S_ISREG(inode->i_mode))
                        return file_ioctl(filp, cmd, argp);
                break;
        }

        return -ENOIOCTLCMD;
}

SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
{
        struct fd f = fdget(fd);
        int error;

        if (!fd_file(f))
                return -EBADF;

        error = security_file_ioctl(fd_file(f), cmd, arg);
        if (error)
                goto out;

        error = do_vfs_ioctl(fd_file(f), fd, cmd, arg);
        if (error == -ENOIOCTLCMD)
                error = vfs_ioctl(fd_file(f), cmd, arg);

out:
        fdput(f);
        return error;
}

#ifdef CONFIG_COMPAT
/**
 * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 * @file: The file to operate on.
 * @cmd: The ioctl command number.
 * @arg: The argument to the ioctl.
 *
 * This is not normally called as a function, but instead set in struct
 * file_operations as
 *
 *     .compat_ioctl = compat_ptr_ioctl,
 *
 * On most architectures, the compat_ptr_ioctl() just passes all arguments
 * to the corresponding ->ioctl handler. The exception is arch/s390, where
 * compat_ptr() clears the top bit of a 32-bit pointer value, so user space
 * pointers to the second 2GB alias the first 2GB, as is the case for
 * native 32-bit s390 user space.
 *
 * The compat_ptr_ioctl() function must therefore be used only with ioctl
 * functions that either ignore the argument or pass a pointer to a
 * compatible data type.
 *
 * If any ioctl command handled by fops->unlocked_ioctl passes a plain
 * integer instead of a pointer, or any of the passed data types
 * is incompatible between 32-bit and 64-bit architectures, a proper
 * handler is required instead of compat_ptr_ioctl.
 */
long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        if (!file->f_op->unlocked_ioctl)
                return -ENOIOCTLCMD;

        return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
EXPORT_SYMBOL(compat_ptr_ioctl);

COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
                       compat_ulong_t, arg)
{
        struct fd f = fdget(fd);
        int error;

        if (!fd_file(f))
                return -EBADF;

        error = security_file_ioctl_compat(fd_file(f), cmd, arg);
        if (error)
                goto out;

        switch (cmd) {
        /* FICLONE takes an int argument, so don't use compat_ptr() */
        case FICLONE:
                error = ioctl_file_clone(fd_file(f), arg, 0, 0, 0);
                break;

#if defined(CONFIG_X86_64)
        /* these get messy on amd64 due to alignment differences */
        case FS_IOC_RESVSP_32:
        case FS_IOC_RESVSP64_32:
                error = compat_ioctl_preallocate(fd_file(f), 0, compat_ptr(arg));
                break;
        case FS_IOC_UNRESVSP_32:
        case FS_IOC_UNRESVSP64_32:
                error = compat_ioctl_preallocate(fd_file(f), FALLOC_FL_PUNCH_HOLE,
                                compat_ptr(arg));
                break;
        case FS_IOC_ZERO_RANGE_32:
                error = compat_ioctl_preallocate(fd_file(f), FALLOC_FL_ZERO_RANGE,
                                compat_ptr(arg));
                break;
#endif

        /*
         * These access 32-bit values anyway so no further handling is
         * necessary.
         */
        case FS_IOC32_GETFLAGS:
        case FS_IOC32_SETFLAGS:
                cmd = (cmd == FS_IOC32_GETFLAGS) ?
                        FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
                fallthrough;
        /*
         * everything else in do_vfs_ioctl() takes either a compatible
         * pointer argument or no argument -- call it with a modified
         * argument.
         */
        default:
                error = do_vfs_ioctl(fd_file(f), fd, cmd,
                                     (unsigned long)compat_ptr(arg));
                if (error != -ENOIOCTLCMD)
                        break;

                if (fd_file(f)->f_op->compat_ioctl)
                        error = fd_file(f)->f_op->compat_ioctl(fd_file(f), cmd, arg);
                if (error == -ENOIOCTLCMD)
                        error = -ENOTTY;
                break;
        }

 out:
        fdput(f);

        return error;
}
#endif