++
++/* So that the fiemap access checks can't overflow on 32 bit machines. */
++#define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
++
++/**
++ * 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
++ * @lun: LUN on which this extent resides
++ *
++ * 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_DIRECT_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED \
++ |FIEMAP_EXTENT_NET)
++#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, dev_t dev)
++{
++ struct fiemap_extent extent = { 0 };
++ struct fiemap_extent *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_DIRECT_FLAGS)
++ flags |= FIEMAP_EXTENT_NO_DIRECT;
++ if (flags & SET_NOT_ALIGNED_FLAGS)
++ flags |= FIEMAP_EXTENT_NOT_ALIGNED;
++ if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
++ flags |= FIEMAP_EXTENT_ENCODED;
++
++ extent.fe_logical = logical;
++ extent.fe_physical = phys;
++ extent.fe_length = len;
++ extent.fe_flags = flags;
++ extent.fe_device = new_encode_dev(dev);
++
++ 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;
++}
++
++static int fiemap_check_ranges(struct super_block *sb,
++ u64 start, u64 len, u64 *new_len)
++{
++ *new_len = len;
++
++ if (len == 0)
++ return -EINVAL;
++
++ if (start > sb->s_maxbytes)
++ return -EFBIG;
++
++ /*
++ * Shrink request scope to what the fs can actually handle.
++ */
++ if ((len > sb->s_maxbytes) ||
++ (sb->s_maxbytes - len) < start)
++ *new_len = sb->s_maxbytes - start;
++
++ return 0;
++}
++
++/*
++ * fiemap_check_flags - check validity of requested flags for fiemap
++ * @fieinfo: Fiemap context passed into ->fiemap
++ * @fs_flags: Set of fiemap flags that the file system understands
++ *
++ * Called from file system ->fiemap callback. This will compute the
++ * intersection of valid fiemap flags and those that the fs supports. That
++ * value is then compared against the user supplied flags. In case of bad user
++ * flags, the invalid values will be written into the fieinfo structure, and
++ * -EBADR is returned, which tells ioctl_fiemap() to return those values to
++ * userspace. For this reason, a return code of -EBADR should be preserved.
++ *
++ * Returns 0 on success, -EBADR on bad flags.
++*/
++int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
++{
++ u32 incompat_flags;
++
++ incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
++ if (incompat_flags) {
++ fieinfo->fi_flags = incompat_flags;
++ return -EBADR;
++ }
++
++ return 0;
++}
++
++int ioctl_fiemap(struct inode *inode, struct file *filp, unsigned long arg)
++{
++ struct fiemap fiemap;
++ u64 len;
++ struct fiemap_extent_info fieinfo = {0, };
++ struct super_block *sb = inode->i_sb;
++ int error = 0;
++
++ if (copy_from_user(&fiemap, (struct fiemap __user *) arg,
++ sizeof(struct fiemap)))
++ return -EFAULT;
++
++ if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
++ return -EINVAL;
++
++ error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
++ &len);
++ if (error)
++ return error;
++
++ fieinfo.fi_flags = fiemap.fm_flags;
++ fieinfo.fi_extents_max = fiemap.fm_extent_count;
++ fieinfo.fi_extents_start = (struct fiemap_extent *)(arg + sizeof(fiemap));
++
++ if (fiemap.fm_extent_count != 0 &&
++ !access_ok(VERIFY_WRITE, (void *)arg,
++ offsetof(typeof(fiemap), fm_extents[fiemap.fm_extent_count])))
++ return -EFAULT;
++
++ if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
++ filemap_write_and_wait(inode->i_mapping);
++
++ error = ext3_fiemap(inode, &fieinfo, fiemap.fm_start, len);
++ fiemap.fm_flags = fieinfo.fi_flags;
++ fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
++ if (copy_to_user((char *)arg, &fiemap, sizeof(fiemap)))
++ error = -EFAULT;
++
++ return error;
++}