vfs: redo vnode locking

kernel-src/fs/devfs.c

@@ -85,12 +85,16 @@ int devfs_lookup(vnode_t *node, char *name, vnode_t **result, cred_t *cred) {
 		return EINVAL;
 
 	void *v;
+	VOP_LOCK(node);
 	int error = hashtable_get(&nametable, &v, name, strlen(name));
-	if (error)
+	if (error) {
+		VOP_UNLOCK(node);
 		return error;
+	}
 
 	vnode_t *rnode = v;
 	VOP_HOLD(rnode);
+	VOP_UNLOCK(node);
 	*result = rnode;
 
 	return 0;
@@ -106,8 +110,10 @@ int devfs_getattr(vnode_t *node, vattr_t *attr, cred_t *cred) {
 		return err;
 	}
 
+	VOP_LOCK(node);
 	*attr = devnode->attr;
 	attr->type = node->type;
+	VOP_UNLOCK(node);
 
 	return 0;
 }
@@ -116,18 +122,18 @@ int devfs_setattr(vnode_t *node, vattr_t *attr, cred_t *cred) {
 	devnode_t *devnode = (devnode_t *)node;
 
 	if (devnode->physical && devnode->physical != node) {
-		VOP_LOCK(devnode->physical);
 		int err = VOP_GETATTR(devnode->physical, attr, cred);
-		VOP_UNLOCK(devnode->physical);
 		return err;
 	}
 
+	VOP_LOCK(node);
 	devnode->attr.gid = attr->gid;
 	devnode->attr.uid = attr->uid;
 	devnode->attr.mode = attr->mode;
 	devnode->attr.atime = attr->atime;
 	devnode->attr.mtime = attr->mtime;
 	devnode->attr.ctime = attr->ctime;
+	VOP_UNLOCK(node);
 	return 0;
 }
 
@@ -170,6 +176,7 @@ int devfs_access(vnode_t *node, mode_t mode, cred_t *cred) {
 }
 
 int devfs_inactive(vnode_t *node) {
+	VOP_LOCK(node);
 	devnode_t *devnode = (devnode_t *)node;
 	vnode_t *master = (vnode_t *)devnode->master;
 	if (devnode->physical && devnode->physical != node)
@@ -186,12 +193,17 @@ int devfs_create(vnode_t *parent, char *name, vattr_t *attr, int type, vnode_t *
 
 	size_t namelen = strlen(name);
 	void *v;
-	if (hashtable_get(&nametable, &v, name, namelen) == 0)
+	VOP_LOCK(parent);
+	if (hashtable_get(&nametable, &v, name, namelen) == 0) {
+		VOP_UNLOCK(parent);
 		return EEXIST;
+	}
 
 	devnode_t *node = slab_allocate(nodecache);
-	if (node == NULL)
+	if (node == NULL) {
+		VOP_UNLOCK(parent);
 		return ENOMEM;
+	}
 
 	timespec_t time = timekeeper_time();
 	vattr_t tmpattr = *attr;
@@ -208,11 +220,13 @@ int devfs_create(vnode_t *parent, char *name, vattr_t *attr, int type, vnode_t *
 
 	int error = hashtable_set(&nametable, node, name, namelen, true);
 	if (error) {
+		VOP_UNLOCK(parent);
 		slab_free(nodecache, node);
 		return error;
 	}
 
 	VOP_HOLD(&node->vnode);
+	VOP_UNLOCK(parent);
 	*result = &node->vnode;
 
 	return 0;

kernel-src/fs/tmpfs.c

@@ -42,6 +42,7 @@ static int tmpfs_poll(vnode_t *node, int event) {
 
 #define DATAMMUFLAGS (ARCH_MMU_FLAGS_WRITE | ARCH_MMU_FLAGS_READ | ARCH_MMU_FLAGS_NOEXEC)
 
+// expects to be called with node locked
 static int tmpfs_resize(tmpfsnode_t *node, size_t size) {
 	if (size == node->attr.size || node->vnode.type != V_TYPE_REGULAR)
 		return 0;
@@ -91,22 +92,28 @@ static int tmpfs_resize(tmpfsnode_t *node, size_t size) {
 }
 
 static int tmpfs_getattr(vnode_t *node, vattr_t *attr, cred_t *cred) {
+	VOP_LOCK(node);
 	tmpfsnode_t *tmpnode = (tmpfsnode_t *)node;
 	*attr = tmpnode->attr;
+	VOP_UNLOCK(node);
 	return 0;
 }
 
 static int tmpfs_setattr(vnode_t *node, vattr_t *attr, cred_t *cred) {
+	VOP_LOCK(node);
 	tmpfsnode_t *tmpnode = (tmpfsnode_t *)node;
 	int err = tmpfs_resize(tmpnode, attr->size);
-	if (err)
+	if (err) {
+		VOP_UNLOCK(node);
 		return err;
+	}
 	tmpnode->attr.gid = attr->gid;
 	tmpnode->attr.uid = attr->uid;
 	tmpnode->attr.mode = attr->mode;
 	tmpnode->attr.atime = attr->atime;
 	tmpnode->attr.mtime = attr->mtime;
 	tmpnode->attr.ctime = attr->ctime;
+	VOP_UNLOCK(node);
 	return 0;
 }
 
@@ -116,13 +123,17 @@ static int tmpfs_lookup(vnode_t *parent, char *name, vnode_t **result, cred_t *c
 	if (parent->type != V_TYPE_DIR)
 		return ENOTDIR;
 
+	VOP_LOCK(parent);
 	void *r;
 	int err = hashtable_get(&tmpparent->children, &r, name, strlen(name));
-	if (err)
+	if (err) {
+		VOP_UNLOCK(parent);
 		return err;
+	}
 
 	child = r;
 	VOP_HOLD(child);
+	VOP_UNLOCK(parent);
 	*result = child;
 	return 0;
 }
@@ -135,13 +146,18 @@ static int tmpfs_create(vnode_t *parent, char *name, vattr_t *attr, int type, vn
 	size_t namelen = strlen(name);
 	void *v;
 
-	if (hashtable_get(&parenttmpnode->children, &v, name, namelen) == 0)
+	VOP_LOCK(parent);
+	if (hashtable_get(&parenttmpnode->children, &v, name, namelen) == 0) {
+		VOP_UNLOCK(parent);
 		return EEXIST;
+	}
 
 	tmpfsnode_t *tmpnode = newnode(parent->vfs, type);
 	vnode_t *node = (vnode_t *)tmpnode;
-	if (tmpnode == NULL)
+	if (tmpnode == NULL) {
+		VOP_UNLOCK(parent);
 		return ENOMEM;
+	}
 
 	timespec_t time = timekeeper_time();
 
@@ -154,6 +170,7 @@ static int tmpfs_create(vnode_t *parent, char *name, vattr_t *attr, int type, vn
 	tmpnode->attr.nlinks = 1;
 
 	if (error) {
+		VOP_UNLOCK(parent);
 		VOP_RELEASE(node);
 		return error; 
 	}
@@ -162,12 +179,14 @@ static int tmpfs_create(vnode_t *parent, char *name, vattr_t *attr, int type, vn
 	if (type == V_TYPE_DIR) {
 		error = hashtable_set(&tmpnode->children, parenttmpnode, "..", 2, true);
 		if (error) {
+			VOP_UNLOCK(parent);
 			VOP_RELEASE(node);
 			return error;
 		}
 	}
 
 	error = hashtable_set(&parenttmpnode->children, tmpnode, name, namelen, true);
+	VOP_UNLOCK(parent);
 
 	if (error) {
 		VOP_RELEASE(node);
@@ -195,10 +214,8 @@ static int tmpfs_open(vnode_t **nodep, int flag, cred_t *cred) {
 		if (err)
 			return err;
 
-		VOP_UNLOCK(node);
 		VOP_RELEASE(node);
 		VOP_HOLD(devnode);
-		VOP_LOCK(devnode);
 		*nodep = devnode; 
 	}
 
@@ -210,6 +227,7 @@ static int tmpfs_close(vnode_t *node, int flag, cred_t *cred) {
 }
 
 static int tmpfs_root(vfs_t *vfs, vnode_t **vnode) {
+	// FIXME lock vfs
 	if (vfs->root) {
 		*vnode = vfs->root;
 		return 0;
@@ -232,9 +250,11 @@ static int tmpfs_read(vnode_t *node, void *buffer, size_t size, uintmax_t offset
 	if (node->type != V_TYPE_REGULAR)
 		return EINVAL;
 
+	VOP_LOCK(node);
 	// offset past end of file
 	if (offset >= tmpnode->attr.size) {
 		*readc = 0;
+		VOP_UNLOCK(node);
 		return 0;
 	}
 
@@ -245,6 +265,7 @@ static int tmpfs_read(vnode_t *node, void *buffer, size_t size, uintmax_t offset
 	*readc = size;
 	memcpy(buffer, (void *)((uintptr_t)tmpnode->data + offset), size);
 
+	VOP_UNLOCK(node);
 	return 0;
 }
 
@@ -255,15 +276,19 @@ static int tmpfs_write(vnode_t *node, void *buffer, size_t size, uintmax_t offse
 
 	size_t top = offset + size;
 
+	VOP_LOCK(node);
 	if (top > tmpnode->attr.size) {
 		int err = tmpfs_resize(tmpnode, top);
-		if (err)
+		if (err) {
+			VOP_UNLOCK(node);
 			return err;
+		}
 	}
 
 	*writec = size;
 	memcpy((void *)((uintptr_t)tmpnode->data + offset), buffer, size);
 
+	VOP_UNLOCK(node);
 	return 0;
 }
 
@@ -279,14 +304,19 @@ static int tmpfs_unlink(vnode_t *node, char *name, cred_t *cred) {
 
 	size_t namelen = strlen(name);
 	void *r;
+	VOP_LOCK(node);
+
 	int err = hashtable_get(&tmpnode->children, &r, name, namelen);
-	if (err)
+	if (err) {
+		VOP_UNLOCK(node);
 		return err;
+	}
 
 	vnode_t *unlinknode = r;
 	tmpfsnode_t *unlinktmpnode = r;
 
 	err = hashtable_remove(&tmpnode->children, name, namelen);
+	VOP_UNLOCK(node);
 	if (err)
 		return err;
 
@@ -305,10 +335,14 @@ static int tmpfs_link(vnode_t *node, vnode_t *dir, char *name, cred_t *cred) {
 	tmpfsnode_t *tmpdir = (tmpfsnode_t *)dir;
 	size_t namelen = strlen(name);
 	void *v;
-	if (hashtable_get(&tmpdir->children, &v, name, namelen) == 0)
+	VOP_LOCK(node);
+	if (hashtable_get(&tmpdir->children, &v, name, namelen) == 0) {
+		VOP_UNLOCK(node);
 		return EEXIST;
+	}
 
 	int error = hashtable_set(&tmpdir->children, node, name, namelen, true);
+	VOP_UNLOCK(dir);
 	if (error)
 		return error;
 
@@ -335,8 +369,10 @@ static int tmpfs_symlink(vnode_t *node, char *name, vattr_t *attr, char *path, c
 		return err;
 	}
 
+	VOP_LOCK(linknode);
 	tmpfsnode_t *linktmpnode = (tmpfsnode_t *)linknode;
 	linktmpnode->link = pathbuf;
+	VOP_UNLOCK(linknode);
 	VOP_RELEASE(linknode);
 
 	return 0;
@@ -348,13 +384,17 @@ static int tmpfs_readlink(vnode_t *node, char **link, cred_t *cred) {
 
 	tmpfsnode_t *tmpnode = (tmpfsnode_t *)node;
 
+	VOP_LOCK(node);
 	char *ret = alloc(strlen(tmpnode->link) + 1);
-	if (ret == NULL)
+	if (ret == NULL) {
+		VOP_UNLOCK(node);
 		return ENOMEM;
+	}
 
 	strcpy(ret, tmpnode->link);
 	*link = ret;
 
+	VOP_UNLOCK(node);
 	return 0;
 }
 

kernel-src/fs/vfs.c

@@ -84,9 +84,7 @@ int vfs_open(vnode_t *ref, char *path, int flags, vnode_t **res) {
 	if (err)
 		return err;
 
-	VOP_LOCK(*res);
 	err = VOP_OPEN(res, flags, getcred());
-	VOP_UNLOCK(*res);
 	if (err)
 		VOP_RELEASE(*res);
 
@@ -94,9 +92,7 @@ int vfs_open(vnode_t *ref, char *path, int flags, vnode_t **res) {
 }
 
 int vfs_close(vnode_t *node, int flags) {
-	VOP_LOCK(node);
 	int err = VOP_CLOSE(node, flags, getcred());
-	VOP_UNLOCK(node);
 	return err;
 }
 
@@ -109,9 +105,7 @@ int vfs_create(vnode_t *ref, char *path, vattr_t *attr, int type, vnode_t **node
 		goto cleanup;
 
 	vnode_t *ret;
-	VOP_LOCK(parent);
 	err = VOP_CREATE(parent, component, attr, type, &ret, getcred());
-	VOP_UNLOCK(parent);
 	VOP_RELEASE(parent);
 	if (err)
 		goto cleanup;
@@ -127,16 +121,12 @@ int vfs_create(vnode_t *ref, char *path, vattr_t *attr, int type, vnode_t **node
 }
 
 int vfs_write(vnode_t *node, void *buffer, size_t size, uintmax_t offset, size_t *written, int flags) {
-	VOP_LOCK(node);
 	int err = VOP_WRITE(node, buffer, size, offset, flags, written, getcred());
-	VOP_UNLOCK(node);
 	return err;
 }
 
 int vfs_read(vnode_t *node, void *buffer, size_t size, uintmax_t offset, size_t *bytesread, int flags) {
-	VOP_LOCK(node);
 	int err = VOP_READ(node, buffer, size, offset, flags, bytesread, getcred());
-	VOP_UNLOCK(node);
 	return err;
 }
 
@@ -160,14 +150,10 @@ int vfs_link(vnode_t *destref, char *destpath, vnode_t *linkref, char *linkpath,
 			VOP_RELEASE(parent);
 			goto cleanup;
 		}
-		VOP_LOCK(parent);
 		err = VOP_LINK(targetnode, parent, component, getcred());
-		VOP_UNLOCK(parent);
 		VOP_RELEASE(targetnode);
 	} else {
-		VOP_LOCK(parent);
 		err = VOP_SYMLINK(parent, component, attr, linkpath, getcred());
-		VOP_UNLOCK(parent);
 	}
 
 	VOP_RELEASE(parent);
@@ -184,9 +170,7 @@ int vfs_unlink(vnode_t *ref, char *path) {
 	if (err)
 		goto cleanup;
 
-	VOP_LOCK(parent);
 	VOP_UNLINK(parent, component, getcred());
-	VOP_UNLOCK(parent);
 	VOP_RELEASE(parent);
 
 	cleanup:
@@ -303,9 +287,7 @@ int vfs_lookup(vnode_t **result, vnode_t *start, char *path, char *lastcomp, int
 			}
 		}
 
-		VOP_LOCK(current);
 		error = VOP_LOOKUP(current, component, &next, getcred());
-		VOP_UNLOCK(current);
 		if (error)
 			break;
 
@@ -326,9 +308,7 @@ int vfs_lookup(vnode_t **result, vnode_t *start, char *path, char *lastcomp, int
 		if (next->type == V_TYPE_LINK && (islast == false || (islast == true && (flags & VFS_LOOKUP_NOLINK) == 0))) {
 			// get path
 			char *linkderef;
-			VOP_LOCK(next);
 			error = VOP_READLINK(next, &linkderef, getcred());
-			VOP_UNLOCK(next);
 			if (error) {
 				VOP_RELEASE(next);
 				break;

kernel-src/mm/vmm.c

@@ -207,9 +207,7 @@ static void destroyrange(vmmcontext_t *context, vmmrange_t *range, uintmax_t _of
 			continue;
 
 		if ((range->flags & VMM_FLAGS_FILE) && (range->flags & VMM_FLAGS_SHARED) && (flags & VMM_DESTROY_FLAGS_NOSYNC) == 0) {
-			VOP_LOCK(range->vnode);
 			__assert(VOP_MUNMAP(range->vnode, vaddr, range->offset + offset, mmuflagstovnodeflags(range->mmuflags), NULL) == 0); // XXX pass cred struct
-			VOP_UNLOCK(range->vnode);
 		} else {
 			pmm_free(physical, 1);
 			arch_mmu_unmap(context->pagetable, vaddr);
@@ -316,9 +314,7 @@ bool vmm_pagefault(void *addr, bool user, int actions) {
 
 	if (range->flags & VMM_FLAGS_FILE) {
 		uintmax_t mapoffset = (uintptr_t)addr - (uintptr_t)range->start;
-		VOP_LOCK(range->vnode);
 		__assert(VOP_MMAP(range->vnode, addr, range->offset + mapoffset, mmuflagstovnodeflags(range->mmuflags), NULL) == 0); // XXX pass cred struct
-		VOP_UNLOCK(range->vnode);
 		status = true;
 	} else {
 		void *paddr = pmm_alloc(1, PMM_SECTION_DEFAULT);

kernel-src/sys/syscalls/open.c

@@ -54,9 +54,7 @@ syscallret_t syscall_openat(context_t *context, int dirfd, const char *path, int
 		goto cleanup;
 
 	vattr_t attr;
-	VOP_LOCK(vnode);
 	ret.errno = VOP_GETATTR(vnode, &attr, &_cpu()->thread->proc->cred);
-	VOP_UNLOCK(vnode);
 	if (ret.errno)
 		goto cleanup;
 

kernel-src/sys/syscalls/seek.c

@@ -49,9 +49,7 @@ syscallret_t syscall_seek(context_t *context, int fd, off_t offset, int whence)
 		}
 		case SEEK_END: {
 			vattr_t attr;
-			VOP_LOCK(file->vnode);
 			ret.errno = VOP_GETATTR(file->vnode, &attr, &_cpu()->thread->proc->cred);
-			VOP_UNLOCK(file->vnode);
 			if (ret.errno) 
 				goto cleanup;
 			file->offset = attr.size;

kernel-src/sys/syscalls/stat.c

@@ -8,9 +8,7 @@
 
 static int dostat(vnode_t *vnode, stat_t *stat) {
 	vattr_t attr;
-	VOP_LOCK(vnode);
 	int e = VOP_GETATTR(vnode, &attr, &_cpu()->thread->proc->cred);
-	VOP_UNLOCK(vnode);
 	if (e)
 		return e;