On Fri, Feb 01, 2019 at 12:51:59PM +0000, Ross Burton wrote: > When copying large files into a ext filesystem at mkfs time the copy fails at > 2^31 bytes in. There are two problems: > > copy_file_chunk() passes an offset (off_t, 64-bit typically) to > ext2fs_file_lseek() which expects a ext2_off_t (typedef to __u32) so the value > is truncated. Solve by calling ext2fs_file_llseek() which takes a u64 offset > instead. > > try_lseek_copy() rounds the data and hole offsets as found by lseek() to block > boundaries, but the calculation gets truncated to 32-bits. Solve by casting the > 32-bit blocksize to off_t to ensure this doesn't happen. > > Signed-off-by: Ross Burton <ross.burton@xxxxxxxxx> > --- > misc/create_inode.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/misc/create_inode.c b/misc/create_inode.c > index 05aa6363..f106dcda 100644 > --- a/misc/create_inode.c > +++ b/misc/create_inode.c > @@ -438,7 +438,7 @@ static errcode_t copy_file_chunk(ext2_filsys fs, int fd, ext2_file_t e2_file, > ptr += blen; > continue; > } > - err = ext2fs_file_lseek(e2_file, off + bpos, > + err = ext2fs_file_llseek(e2_file, off + bpos, > EXT2_SEEK_SET, NULL); > if (err) > goto fail; > @@ -481,7 +481,7 @@ static errcode_t try_lseek_copy(ext2_filsys fs, int fd, struct stat *statbuf, > return EXT2_ET_UNIMPLEMENTED; > > data_blk = data & ~(fs->blocksize - 1); Do we need to cast this one too? ^^^^^^^ (Looks reasonable otherwise...) --D > - hole_blk = (hole + (fs->blocksize - 1)) & ~(fs->blocksize - 1); > + hole_blk = (hole + (off_t)(fs->blocksize - 1)) & ~(off_t)(fs->blocksize - 1); > err = copy_file_chunk(fs, fd, e2_file, data_blk, hole_blk, buf, > zerobuf); > if (err) > -- > 2.11.0 >
