diff options
| -rw-r--r-- | sys/ufs/ufs/ufs_extattr.c | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/sys/ufs/ufs/ufs_extattr.c b/sys/ufs/ufs/ufs_extattr.c index e5155dd..ae0c0fb 100644 --- a/sys/ufs/ufs/ufs_extattr.c +++ b/sys/ufs/ufs/ufs_extattr.c @@ -443,7 +443,7 @@ ufs_extattr_get(struct vnode *vp, char *name, struct uio *uio, struct mount *mp = vp->v_mount; struct ufsmount *ump = VFSTOUFS(mp); struct inode *ip = VTOI(vp); - off_t base_offset, old_offset, offset; + off_t base_offset, offset; size_t size, old_size; int error = 0; @@ -459,10 +459,12 @@ ufs_extattr_get(struct vnode *vp, char *name, struct uio *uio, return (error); /* - * Early rejection of offsets that are invalid + * Allow only offsets of zero to encourage the read/replace + * extended attribute semantic. Otherwise we can't guarantee + * atomicity, as we don't provide locks for extended + * attributes. */ - if (uio->uio_offset >= attribute->uele_fileheader.uef_size || - uio->uio_offset < 0) + if (uio->uio_offset != 0) return (ENXIO); /* @@ -529,28 +531,24 @@ ufs_extattr_get(struct vnode *vp, char *name, struct uio *uio, } /* allow for offset into the attr data */ - offset = base_offset + sizeof(struct ufs_extattr_header) + - uio->uio_offset; + uio->uio_offset = base_offset + sizeof(struct ufs_extattr_header); /* * Figure out maximum to transfer -- use buffer size and local data * limit. */ - size = MIN(uio->uio_resid, ueh.ueh_len - uio->uio_offset); - - old_offset = uio->uio_offset; - uio->uio_offset = offset; + size = MIN(uio->uio_resid, ueh.ueh_len); old_size = uio->uio_resid; uio->uio_resid = size; error = VOP_READ(attribute->uele_backing_vnode, uio, 0, ump->um_extattr.uepm_ucred); if (error) { - uio->uio_offset = old_offset; + uio->uio_offset = 0; goto vopunlock_exit; } - uio->uio_offset = old_offset; + uio->uio_offset = 0; uio->uio_resid = old_size - (size - uio->uio_resid); vopunlock_exit: |
