Module Name: src
Committed By: rmind
Date: Thu May 19 03:13:58 UTC 2011
Modified Files:
src/sys/fs/tmpfs: tmpfs_vnops.c
Log Message:
Add comments, clean up.
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/fs/tmpfs/tmpfs_vnops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/fs/tmpfs/tmpfs_vnops.c
diff -u src/sys/fs/tmpfs/tmpfs_vnops.c:1.81 src/sys/fs/tmpfs/tmpfs_vnops.c:1.82
--- src/sys/fs/tmpfs/tmpfs_vnops.c:1.81 Thu May 19 03:11:58 2011
+++ src/sys/fs/tmpfs/tmpfs_vnops.c Thu May 19 03:13:58 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: tmpfs_vnops.c,v 1.81 2011/05/19 03:11:58 rmind Exp $ */
+/* $NetBSD: tmpfs_vnops.c,v 1.82 2011/05/19 03:13:58 rmind Exp $ */
/*
* Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tmpfs_vnops.c,v 1.81 2011/05/19 03:11:58 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tmpfs_vnops.c,v 1.82 2011/05/19 03:13:58 rmind Exp $");
#include <sys/param.h>
#include <sys/dirent.h>
@@ -115,7 +115,7 @@
{ &tmpfs_vnodeop_p, tmpfs_vnodeop_entries };
/*
- * tmpfs_lookup: lookup routine.
+ * tmpfs_lookup: path name traversal routine.
*
* Arguments: dvp (directory being searched), vpp (result),
* cnp (component name - path).
@@ -163,25 +163,30 @@
* directory/name couple is already in the cache.
*/
error = cache_lookup(dvp, vpp, cnp);
- if (error >= 0)
+ if (error >= 0) {
+ /* Both cache-hit or an error case. */
goto out;
-
- /* We cannot be requesting the parent directory of the root node. */
- KASSERT(IMPLIES(dnode->tn_type == VDIR &&
- dnode->tn_spec.tn_dir.tn_parent == dnode,
- !(cnp->cn_flags & ISDOTDOT)));
+ }
if (cnp->cn_flags & ISDOTDOT) {
+ struct tmpfs_node *pnode;
+ /*
+ * Lookup of ".." case.
+ */
+ pnode = dnode->tn_spec.tn_dir.tn_parent;
+ KASSERT(dnode->tn_type == VDIR && pnode != dnode);
VOP_UNLOCK(dvp);
/* Allocate a new vnode on the matching entry. */
- error = tmpfs_alloc_vp(dvp->v_mount,
- dnode->tn_spec.tn_dir.tn_parent, vpp);
+ error = tmpfs_alloc_vp(dvp->v_mount, pnode, vpp);
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
- goto done;
+ goto out;
} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
+ /*
+ * Lookup of "." case.
+ */
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop == RENAME)) {
error = EISDIR;
@@ -193,6 +198,9 @@
goto done;
}
+ /*
+ * Other lookup cases: perform directory scan.
+ */
de = tmpfs_dir_lookup(dnode, cnp);
if (de == NULL || de->td_node == TMPFS_NODE_WHITEOUT) {
/*
@@ -263,14 +271,12 @@
}
done:
/*
- * Store the result of this lookup in the cache. Avoid this if the
- * request was for creation, as it does not improve timings on
- * emprical tests.
+ * Cache the result, unless request was for creation (as it does
+ * not improve the performance).
*/
- if ((cnp->cn_flags & MAKEENTRY) && cnp->cn_nameiop != CREATE &&
- (cnp->cn_flags & ISDOTDOT) == 0)
+ if ((cnp->cn_flags & MAKEENTRY) != 0 && cnp->cn_nameiop != CREATE) {
cache_enter(dvp, *vpp, cnp);
-
+ }
out:
KASSERT(IFF(error == 0, *vpp != NULL && VOP_ISLOCKED(*vpp)));
KASSERT(VOP_ISLOCKED(dvp));
@@ -680,20 +686,20 @@
return 0;
}
-/* --------------------------------------------------------------------- */
-
int
tmpfs_remove(void *v)
{
- struct vnode *dvp = ((struct vop_remove_args *)v)->a_dvp;
- struct vnode *vp = ((struct vop_remove_args *)v)->a_vp;
- struct componentname *cnp = (((struct vop_remove_args *)v)->a_cnp);
-
- int error;
+ struct vop_remove_args /* {
+ struct vnode *a_dvp;
+ struct vnode *a_vp;
+ struct componentname *a_cnp;
+ } */ *ap = v;
+ struct vnode *dvp = ap->a_dvp, *vp = ap->a_vp;
+ struct componentname *cnp = ap->a_cnp;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
- struct tmpfs_node *dnode;
- struct tmpfs_node *node;
+ struct tmpfs_node *dnode, *node;
+ int error;
KASSERT(VOP_ISLOCKED(dvp));
KASSERT(VOP_ISLOCKED(vp));
@@ -703,12 +709,7 @@
goto out;
}
- dnode = VP_TO_TMPFS_DIR(dvp);
node = VP_TO_TMPFS_NODE(vp);
- tmp = VFS_TO_TMPFS(vp->v_mount);
- de = tmpfs_dir_lookup(dnode, cnp);
- KASSERT(de);
- KASSERT(de->td_node == node);
/* Files marked as immutable or append-only cannot be deleted. */
if (node->tn_flags & (IMMUTABLE | APPEND)) {
@@ -716,17 +717,22 @@
goto out;
}
- /* Remove the entry from the directory; as it is a file, we do not
- * have to change the number of hard links of the directory. */
+ /*
+ * Lookup and remove the entry from the directory. Note that since
+ * it is a file, we do not need to change the number of hard links.
+ */
+ dnode = VP_TO_TMPFS_DIR(dvp);
+ de = tmpfs_dir_lookup(dnode, cnp);
+ KASSERT(de && de->td_node == node);
tmpfs_dir_detach(dvp, de);
- /* Free the directory entry we just deleted. Note that the node
- * referred by it will not be removed until the vnode is really
- * reclaimed. */
+ /*
+ * Free removed directory entry. Note that the node referred by it
+ * will not be removed until the vnode is really reclaimed.
+ */
+ tmp = VFS_TO_TMPFS(vp->v_mount);
tmpfs_free_dirent(tmp, de, true);
-
error = 0;
-
out:
vput(vp);
if (dvp == vp)
@@ -750,7 +756,7 @@
} */ *ap = v;
struct vnode *dvp = ap->a_dvp;
struct vnode *vp = ap->a_vp;
- struct componentname *cnp = ap->a_cnp;;
+ struct componentname *cnp = ap->a_cnp;
struct tmpfs_node *dnode, *node;
struct tmpfs_dirent *de;
int error;
@@ -1260,52 +1266,46 @@
return error;
}
-/* --------------------------------------------------------------------- */
-
int
tmpfs_inactive(void *v)
{
- struct vnode *vp = ((struct vop_inactive_args *)v)->a_vp;
-
+ struct vop_inactive_args /* {
+ struct vnode *a_vp;
+ bool *a_recycle;
+ } */ *ap = v;
+ struct vnode *vp = ap->a_vp;
struct tmpfs_node *node;
KASSERT(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
- *((struct vop_inactive_args *)v)->a_recycle = (node->tn_links == 0);
+ *ap->a_recycle = (node->tn_links == 0);
VOP_UNLOCK(vp);
return 0;
}
-/* --------------------------------------------------------------------- */
-
int
tmpfs_reclaim(void *v)
{
- struct vnode *vp = ((struct vop_reclaim_args *)v)->a_vp;
-
- struct tmpfs_mount *tmp;
- struct tmpfs_node *node;
-
- node = VP_TO_TMPFS_NODE(vp);
- tmp = VFS_TO_TMPFS(vp->v_mount);
+ struct vop_reclaim_args /* {
+ struct vnode *a_vp;
+ } */ *ap = v;
+ struct vnode *vp = ap->a_vp;
+ struct tmpfs_mount *tmp = VFS_TO_TMPFS(vp->v_mount);
+ struct tmpfs_node *node = VP_TO_TMPFS_NODE(vp);
+ /* Disassociate inode from vnode. */
tmpfs_free_vp(vp);
-
- /* If the node referenced by this vnode was deleted by the user,
- * we must free its associated data structures (now that the vnode
- * is being reclaimed). */
- if (node->tn_links == 0)
- tmpfs_free_node(tmp, node);
-
KASSERT(vp->v_data == NULL);
+ /* If inode is not referenced, i.e. no links, then destroy it. */
+ if (node->tn_links == 0) {
+ tmpfs_free_node(tmp, node);
+ }
return 0;
}
-/* --------------------------------------------------------------------- */
-
int
tmpfs_print(void *v)
{
