cifs: fix DFS failover

[mirror_ubuntu-hirsute-kernel.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 "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.
 */
#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)
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;

        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 (!src_file.file)
                return -EBADF;
        ret = -EXDEV;
        if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
                goto fdput;
        cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
                                      olen, 0);
        if (cloned < 0)
                ret = cloned;
        else if (olen && cloned != olen)
                ret = -EINVAL;
        else
                ret = 0;
fdput:
        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);
}

#ifdef CONFIG_BLOCK

static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
{
        return (offset >> inode->i_blkbits);
}

static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
{
        return (blk << inode->i_blkbits);
}

/**
 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
 * @inode: the inode to map
 * @fieinfo: the fiemap info struct that will be passed back to userspace
 * @start: where to start mapping in the inode
 * @len: how much space to map
 * @get_block: the fs's get_block function
 *
 * This does FIEMAP for block based inodes.  Basically it will just loop
 * through get_block until we hit the number of extents we want to map, or we
 * go past the end of the file and hit a hole.
 *
 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
 * please do not use this function, it will stop at the first unmapped block
 * beyond i_size.
 *
 * If you use this function directly, you need to do your own locking. Use
 * generic_block_fiemap if you want the locking done for you.
 */
static int __generic_block_fiemap(struct inode *inode,
                           struct fiemap_extent_info *fieinfo, loff_t start,
                           loff_t len, get_block_t *get_block)
{
        struct buffer_head map_bh;
        sector_t start_blk, last_blk;
        loff_t isize = i_size_read(inode);
        u64 logical = 0, phys = 0, size = 0;
        u32 flags = FIEMAP_EXTENT_MERGED;
        bool past_eof = false, whole_file = false;
        int ret = 0;

        ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
        if (ret)
                return ret;

        /*
         * Either the i_mutex or other appropriate locking needs to be held
         * since we expect isize to not change at all through the duration of
         * this call.
         */
        if (len >= isize) {
                whole_file = true;
                len = isize;
        }

        /*
         * Some filesystems can't deal with being asked to map less than
         * blocksize, so make sure our len is at least block length.
         */
        if (logical_to_blk(inode, len) == 0)
                len = blk_to_logical(inode, 1);

        start_blk = logical_to_blk(inode, start);
        last_blk = logical_to_blk(inode, start + len - 1);

        do {
                /*
                 * we set b_size to the total size we want so it will map as
                 * many contiguous blocks as possible at once
                 */
                memset(&map_bh, 0, sizeof(struct buffer_head));
                map_bh.b_size = len;

                ret = get_block(inode, start_blk, &map_bh, 0);
                if (ret)
                        break;

                /* HOLE */
                if (!buffer_mapped(&map_bh)) {
                        start_blk++;

                        /*
                         * We want to handle the case where there is an
                         * allocated block at the front of the file, and then
                         * nothing but holes up to the end of the file properly,
                         * to make sure that extent at the front gets properly
                         * marked with FIEMAP_EXTENT_LAST
                         */
                        if (!past_eof &&
                            blk_to_logical(inode, start_blk) >= isize)
                                past_eof = 1;

                        /*
                         * First hole after going past the EOF, this is our
                         * last extent
                         */
                        if (past_eof && size) {
                                flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
                                ret = fiemap_fill_next_extent(fieinfo, logical,
                                                              phys, size,
                                                              flags);
                        } else if (size) {
                                ret = fiemap_fill_next_extent(fieinfo, logical,
                                                              phys, size, flags);
                                size = 0;
                        }

                        /* if we have holes up to/past EOF then we're done */
                        if (start_blk > last_blk || past_eof || ret)
                                break;
                } else {
                        /*
                         * We have gone over the length of what we wanted to
                         * map, and it wasn't the entire file, so add the extent
                         * we got last time and exit.
                         *
                         * This is for the case where say we want to map all the
                         * way up to the second to the last block in a file, but
                         * the last block is a hole, making the second to last
                         * block FIEMAP_EXTENT_LAST.  In this case we want to
                         * see if there is a hole after the second to last block
                         * so we can mark it properly.  If we found data after
                         * we exceeded the length we were requesting, then we
                         * are good to go, just add the extent to the fieinfo
                         * and break
                         */
                        if (start_blk > last_blk && !whole_file) {
                                ret = fiemap_fill_next_extent(fieinfo, logical,
                                                              phys, size,
                                                              flags);
                                break;
                        }

                        /*
                         * if size != 0 then we know we already have an extent
                         * to add, so add it.
                         */
                        if (size) {
                                ret = fiemap_fill_next_extent(fieinfo, logical,
                                                              phys, size,
                                                              flags);
                                if (ret)
                                        break;
                        }

                        logical = blk_to_logical(inode, start_blk);
                        phys = blk_to_logical(inode, map_bh.b_blocknr);
                        size = map_bh.b_size;
                        flags = FIEMAP_EXTENT_MERGED;

                        start_blk += logical_to_blk(inode, size);

                        /*
                         * If we are past the EOF, then we need to make sure as
                         * soon as we find a hole that the last extent we found
                         * is marked with FIEMAP_EXTENT_LAST
                         */
                        if (!past_eof && logical + size >= isize)
                                past_eof = true;
                }
                cond_resched();
                if (fatal_signal_pending(current)) {
                        ret = -EINTR;
                        break;
                }

        } while (1);

        /* If ret is 1 then we just hit the end of the extent array */
        if (ret == 1)
                ret = 0;

        return ret;
}

/**
 * generic_block_fiemap - FIEMAP for block based inodes
 * @inode: The inode to map
 * @fieinfo: The mapping information
 * @start: The initial block to map
 * @len: The length of the extect to attempt to map
 * @get_block: The block mapping function for the fs
 *
 * Calls __generic_block_fiemap to map the inode, after taking
 * the inode's mutex lock.
 */

int generic_block_fiemap(struct inode *inode,
                         struct fiemap_extent_info *fieinfo, u64 start,
                         u64 len, get_block_t *get_block)
{
        int ret;
        inode_lock(inode);
        ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
        inode_unlock(inode);
        return ret;
}
EXPORT_SYMBOL(generic_block_fiemap);

#endif  /*  CONFIG_BLOCK  */

/*
 * 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);
        return freeze_super(sb);
}

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);
        return thaw_super(sb);
}

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 __user, 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;
}

/*
 * 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.
 */
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);

        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 (!f.file)
                return -EBADF;

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

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

out:
        fdput(f);
        return error;
}

#ifdef CONFIG_COMPAT
/**
 * compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
 *
 * 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 (!f.file)
                return -EBADF;

        /* RED-PEN how should LSM module know it's handling 32bit? */
        error = security_file_ioctl(f.file, 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(f.file, 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(f.file, 0, compat_ptr(arg));
                break;
        case FS_IOC_UNRESVSP_32:
        case FS_IOC_UNRESVSP64_32:
                error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
                                compat_ptr(arg));
                break;
        case FS_IOC_ZERO_RANGE_32:
                error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
                                compat_ptr(arg));
                break;
#endif

        /*
         * 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(f.file, fd, cmd,
                                     (unsigned long)compat_ptr(arg));
                if (error != -ENOIOCTLCMD)
                        break;

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

 out:
        fdput(f);

        return error;
}
#endif