On 28/02/16(Sun) 13:14, Martin Natano wrote:
> The ext2fs_read() and ffs_read() functions return EFBIG when uio_offset
> if smaller than zero or larger than the maxium file size. However this
> doesn't seem to be in accordance with the POSIX read(2) specification,
> which requires EINVAL for an invalid offset (< 2) and a return of 0
> (zero bytes transferred) for an offset that's at or paste the EOF. EFBIG
> actually means "File too large", which is clearly not true in both
> cases.
This seems to be coherent with MSDOSFS.
I'm also wondering when you say "an offset that's at or paste the
EOF" does that include ``uio_resid''? I mean shouldn't you check
for:
if ((uio->uio_offset + uio->uio_resid) > fs->fs_maxfilesize)
...
> Index: ufs/ext2fs/ext2fs_readwrite.c
> ===================================================================
> RCS file: /cvs/src/sys/ufs/ext2fs/ext2fs_readwrite.c,v
> retrieving revision 1.39
> diff -u -p -r1.39 ext2fs_readwrite.c
> --- ufs/ext2fs/ext2fs_readwrite.c 27 Feb 2016 18:50:38 -0000 1.39
> +++ ufs/ext2fs/ext2fs_readwrite.c 28 Feb 2016 09:10:16 -0000
> @@ -100,9 +100,9 @@ ext2_ind_read(struct vnode *vp, struct i
> } else if (vp->v_type != VREG && vp->v_type != VDIR)
> panic("%s: type %d", "ext2fs_read", vp->v_type);
> #endif
> - if (e2fs_overflow(fs, 0, uio->uio_offset))
> - return (EFBIG);
> - if (uio->uio_resid == 0)
> + if (uio->uio_offset < 0)
> + return (EINVAL);
> + if (uio->uio_offset > fs->e2fs_maxfilesize || uio->uio_resid == 0)
> return (0);
>
> for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
> @@ -163,7 +163,6 @@ ext4_ext_read(struct vnode *vp, struct i
> struct ext4_extent_path path;
> struct ext4_extent nex, *ep;
> struct buf *bp;
> - size_t orig_resid;
> daddr_t lbn, pos;
> off_t bytesinfile;
> int size, xfersize, blkoffset;
> @@ -171,12 +170,10 @@ ext4_ext_read(struct vnode *vp, struct i
>
> memset(&path, 0, sizeof path);
>
> - orig_resid = uio->uio_resid;
> - if (orig_resid == 0)
> + if (uio->uio_offset < 0)
> + return (EINVAL);
> + if (uio->uio_offset > fs->e2fs_maxfilesize || uio->uio_resid == 0)
> return (0);
> -
> - if (e2fs_overflow(fs, 0, uio->uio_offset))
> - return (EFBIG);
>
> while (uio->uio_resid > 0) {
> if ((bytesinfile = ext2fs_size(ip) - uio->uio_offset) <= 0)
> Index: ufs/ffs/ffs_vnops.c
> ===================================================================
> RCS file: /cvs/src/sys/ufs/ffs/ffs_vnops.c,v
> retrieving revision 1.84
> diff -u -p -r1.84 ffs_vnops.c
> --- ufs/ffs/ffs_vnops.c 27 Feb 2016 18:50:38 -0000 1.84
> +++ ufs/ffs/ffs_vnops.c 28 Feb 2016 09:10:16 -0000
> @@ -214,10 +214,9 @@ ffs_read(void *v)
> panic("ffs_read: type %d", vp->v_type);
> #endif
> fs = ip->i_fs;
> - if ((u_int64_t)uio->uio_offset > fs->fs_maxfilesize)
> - return (EFBIG);
> -
> - if (uio->uio_resid == 0)
> + if (uio->uio_offset < 0)
> + return (EINVAL);
> + if (uio->uio_offset > fs->fs_maxfilesize || uio->uio_resid == 0)
> return (0);
>
> for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
>
