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Fixed crashing bug in remove_vnode(): it freed the vnode, but it didn't

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remove it from the hash, and thus, left a dead pointer around.
free_vnode() does now also remove the vnode from the hash - this is done
so that the file system is notified about removal/put of the vnode before
there is a chance that this vnode is recreated/reloaded (could make the
life of file system writers a bit easier).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13877 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2005-08-02 11:20:04 +00:00
parent bef4185e93
commit c50cfe23dd
1 changed files with 23 additions and 10 deletions
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33
src/system/kernel/fs/vfs.cpp
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@ -641,7 +641,8 @@ create_new_vnode(struct vnode **_vnode, mount_id mountID, vnode_id vnodeID)
} }
/** Frees the vnode and all resources it has acquired. /** Frees the vnode and all resources it has acquired, and removes
* it from the vnode hash as well as from its mount structure.
* Will also make sure that any cache modifications are written back. * Will also make sure that any cache modifications are written back.
*/ */
@ -664,6 +665,12 @@ free_vnode(struct vnode *vnode, bool reenter)
FS_CALL(vnode, put_vnode)(vnode->mount->cookie, vnode->private_node, reenter); FS_CALL(vnode, put_vnode)(vnode->mount->cookie, vnode->private_node, reenter);
} }
// The file system has removed the resources of the vnode now, so we can
// make it available again (and remove the busy vnode from the hash)
mutex_lock(&sVnodeMutex);
hash_remove(sVnodeTable, vnode);
mutex_unlock(&sVnodeMutex);
// if we have a vm_cache attached, remove it // if we have a vm_cache attached, remove it
if (vnode->cache) if (vnode->cache)
vm_cache_release_ref(vnode->cache); vm_cache_release_ref(vnode->cache);
@ -709,7 +716,6 @@ dec_vnode_ref_count(struct vnode *vnode, bool reenter)
// Just insert the vnode into an unused list if we don't need // Just insert the vnode into an unused list if we don't need
// to delete it // to delete it
if (vnode->remove) { if (vnode->remove) {
hash_remove(sVnodeTable, vnode);
vnode->busy = true; vnode->busy = true;
freeNode = true; freeNode = true;
} else { } else {
@ -718,7 +724,6 @@ dec_vnode_ref_count(struct vnode *vnode, bool reenter)
// there are too many unused vnodes so we free the oldest one // there are too many unused vnodes so we free the oldest one
// ToDo: evaluate this mechanism // ToDo: evaluate this mechanism
vnode = (struct vnode *)list_remove_head_item(&sUnusedVnodeList); vnode = (struct vnode *)list_remove_head_item(&sUnusedVnodeList);
hash_remove(sVnodeTable, vnode);
vnode->busy = true; vnode->busy = true;
freeNode = true; freeNode = true;
sUnusedVnodes--; sUnusedVnodes--;
@ -1981,7 +1986,8 @@ get_new_fd(int type, struct fs_mount *mount, struct vnode *vnode,
extern "C" status_t extern "C" status_t
new_vnode(mount_id mountID, vnode_id vnodeID, fs_vnode privateNode) new_vnode(mount_id mountID, vnode_id vnodeID, fs_vnode privateNode)
{ {
FUNCTION(("new_vnode()\n")); FUNCTION(("new_vnode(mountID = %ld, vnodeID = %Ld, node = %p)\n",
mountID, vnodeID, privateNode));
if (privateNode == NULL) if (privateNode == NULL)
return B_BAD_VALUE; return B_BAD_VALUE;
@ -2074,6 +2080,7 @@ extern "C" status_t
remove_vnode(mount_id mountID, vnode_id vnodeID) remove_vnode(mount_id mountID, vnode_id vnodeID)
{ {
struct vnode *vnode; struct vnode *vnode;
bool remove = false;
mutex_lock(&sVnodeMutex); mutex_lock(&sVnodeMutex);
@ -2081,13 +2088,20 @@ remove_vnode(mount_id mountID, vnode_id vnodeID)
if (vnode != NULL) { if (vnode != NULL) {
vnode->remove = true; vnode->remove = true;
if (vnode->unpublished) { if (vnode->unpublished) {
// if the vnode hasn't been published yet, we delete it here // prepare the vnode for deletion
atomic_add(&vnode->ref_count, -1); vnode->busy = true;
free_vnode(vnode, true); remove = true;
} }
} }
mutex_unlock(&sVnodeMutex); mutex_unlock(&sVnodeMutex);
if (remove) {
// if the vnode hasn't been published yet, we delete it here
atomic_add(&vnode->ref_count, -1);
free_vnode(vnode, true);
}
return B_OK; return B_OK;
} }
@ -2771,7 +2785,7 @@ vfs_bootstrap_file_systems(void)
if (status < B_OK) { if (status < B_OK) {
// this is no fatal exception at this point, as we may mount // this is no fatal exception at this point, as we may mount
// a real on disk file system later // a real on disk file system later
dprintf("error mounting bootfs\n"); dprintf("Can't mount bootfs (will try disk file system later)\n");
} }
// create some standard links on the rootfs // create some standard links on the rootfs
@ -4866,7 +4880,6 @@ fs_unmount(char *path, uint32 flags, bool kernel)
while ((vnode = (struct vnode *)list_get_next_item(&mount->vnodes, vnode)) != NULL) { while ((vnode = (struct vnode *)list_get_next_item(&mount->vnodes, vnode)) != NULL) {
vnode->busy = true; vnode->busy = true;
hash_remove(sVnodeTable, vnode);
} }
mutex_unlock(&sVnodeMutex); mutex_unlock(&sVnodeMutex);
@ -4877,7 +4890,7 @@ fs_unmount(char *path, uint32 flags, bool kernel)
// Free all vnodes associated with this mount. // Free all vnodes associated with this mount.
// They will be removed from the mount list by free_vnode(), so // They will be removed from the mount list by free_vnode(), so
// we don't have to do this. // we don't have to do this.
while ((vnode = (struct vnode *)list_get_next_item(&mount->vnodes, NULL)) != NULL) { while ((vnode = (struct vnode *)list_get_first_item(&mount->vnodes)) != NULL) {
free_vnode(vnode, false); free_vnode(vnode, false);
} }