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Added treatments to prevent readdir infinity loop using with Linux binary

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compatibility feature.

Submitted by:   Masanori Ozawa <ozawa@ongs.co.jp> (unionfs developer)
Reviewed by:    jeff, kensmith
Approved by:    re (kensmith)
MFC after:      1 week
This commit is contained in:
daichi 2007-10-14 13:44:06 +00:00
parent a763e0d0a2
commit 4aad1608ad
1 changed files with 23 additions and 29 deletions
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52
sys/fs/unionfs/union_vnops.c
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@ -1388,41 +1388,41 @@ unionfs_readdir(struct vop_readdir_args *ap)
/* check opaque */
if (uvp != NULLVP && lvp != NULLVP) {
if ((error = VOP_GETATTR(uvp, &va, ap->a_cred, td)) != 0)
return (error);
goto unionfs_readdir_exit;
if (va.va_flags & OPAQUE)
lvp = NULLVP;
}
/* check the open count. unionfs needs to open before readdir. */
if (VOP_ISLOCKED(ap->a_vp, td) != LK_EXCLUSIVE) {
vn_lock(ap->a_vp, LK_UPGRADE | LK_RETRY, td);
locked = 1;
}
unionfs_get_node_status(unp, curthread, &unsp);
unionfs_get_node_status(unp, td, &unsp);
if ((uvp != NULLVP && unsp->uns_upper_opencnt <= 0) ||
(lvp != NULLVP && unsp->uns_lower_opencnt <= 0)) {
unionfs_tryrem_node_status(unp, td, unsp);
error = EBADF;
}
if (locked == 1)
vn_lock(ap->a_vp, LK_DOWNGRADE | LK_RETRY, td);
if (error != 0)
goto unionfs_readdir_exit;
/* upper only */
if (uvp != NULLVP && lvp == NULLVP) {
if (unsp->uns_upper_opencnt <= 0)
error = EBADF;
else {
error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
ap->a_ncookies, ap->a_cookies);
unsp->uns_readdir_status = 0;
}
error = VOP_READDIR(uvp, uio, ap->a_cred, ap->a_eofflag,
ap->a_ncookies, ap->a_cookies);
unsp->uns_readdir_status = 0;
goto unionfs_readdir_exit;
}
/* lower only */
if (uvp == NULLVP && lvp != NULLVP) {
if (unsp->uns_lower_opencnt <= 0)
error = EBADF;
else {
error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
ap->a_ncookies, ap->a_cookies);
unsp->uns_readdir_status = 2;
}
error = VOP_READDIR(lvp, uio, ap->a_cred, ap->a_eofflag,
ap->a_ncookies, ap->a_cookies);
unsp->uns_readdir_status = 2;
goto unionfs_readdir_exit;
}
@ -1430,11 +1430,6 @@ unionfs_readdir(struct vop_readdir_args *ap)
/*
* readdir upper and lower
*/
if (unsp->uns_lower_opencnt <= 0 || unsp->uns_upper_opencnt <= 0) {
error = EBADF;
goto unionfs_readdir_exit;
}
if (uio->uio_offset == 0)
unsp->uns_readdir_status = 0;
@ -1443,10 +1438,8 @@ unionfs_readdir(struct vop_readdir_args *ap)
error = VOP_READDIR(uvp, uio, ap->a_cred, &eofflag,
ap->a_ncookies, ap->a_cookies);
if (error != 0 || eofflag == 0) {
UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
return (error);
}
if (error != 0 || eofflag == 0)
goto unionfs_readdir_exit;
unsp->uns_readdir_status = 1;
/*
@ -1455,10 +1448,8 @@ unionfs_readdir(struct vop_readdir_args *ap)
* size of DIRBLKSIZ equals DEV_BSIZE.
* (see: ufs/ufs/ufs_vnops.c ufs_readdir func , ufs/ufs/dir.h)
*/
if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1))) {
UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
return (0);
}
if (uio->uio_resid <= (uio->uio_resid & (DEV_BSIZE -1)))
goto unionfs_readdir_exit;
/*
* backup cookies
@ -1508,6 +1499,9 @@ unionfs_readdir(struct vop_readdir_args *ap)
}
unionfs_readdir_exit:
if (error != 0 && ap->a_eofflag != NULL)
*(ap->a_eofflag) = 1;
UNIONFS_INTERNAL_DEBUG("unionfs_readdir: leave (%d)\n", error);
return (error);