From: Stefan Hajnoczi <stefa...@redhat.com>
Do not expose lo_inode pointers to clients.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
contrib/virtiofsd/passthrough_ll.c | 125 ++++++++++++++++++++++++-----
1 file changed, 105 insertions(+), 20 deletions(-)
diff --git a/contrib/virtiofsd/passthrough_ll.c
b/contrib/virtiofsd/passthrough_ll.c
index 3093d1171e..f718c951f7 100644
--- a/contrib/virtiofsd/passthrough_ll.c
+++ b/contrib/virtiofsd/passthrough_ll.c
@@ -56,8 +56,8 @@
#define HAVE_POSIX_FALLOCATE 1
-/* We are re-using pointers to our `struct lo_inode` and `struct
- lo_dirp` elements as inodes. This means that we must be able to
+/* We are re-using pointers to our `struct lo_dirp`
+ elements as inodes. This means that we must be able to
store uintptr_t values in a fuse_ino_t variable. The following
incantation checks this condition at compile time. */
#if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >=
6) && !defined __cplusplus
@@ -71,7 +71,7 @@ struct _uintptr_to_must_hold_fuse_ino_t_dummy_struct \
struct lo_map_elem {
union {
- /* Element values will go here... */
+ struct lo_inode *inode;
ssize_t freelist;
};
bool in_use;
@@ -92,6 +92,7 @@ struct lo_inode {
ino_t ino;
dev_t dev;
uint64_t refcount; /* protected by lo->mutex */
+ fuse_ino_t fuse_ino;
};
struct lo_cred {
@@ -116,6 +117,7 @@ struct lo_data {
int cache;
int timeout_set;
struct lo_inode root; /* protected by lo->mutex */
+ struct lo_map ino_map; /* protected by lo->mutex */
};
static const struct fuse_opt lo_opts[] = {
@@ -250,17 +252,38 @@ static void lo_map_remove(struct lo_map *map, size_t key)
map->freelist = key;
}
+/* Assumes lo->mutex is held */
+static ssize_t lo_add_inode_mapping(fuse_req_t req, struct lo_inode *inode)
+{
+ struct lo_map_elem *elem;
+
+ elem = lo_map_alloc_elem(&lo_data(req)->ino_map);
+ if (!elem)
+ return -1;
+
+ elem->inode = inode;
+ return elem - lo_data(req)->ino_map.elems;
+}
+
static struct lo_inode *lo_inode(fuse_req_t req, fuse_ino_t ino)
{
- if (ino == FUSE_ROOT_ID)
- return &lo_data(req)->root;
- else
- return (struct lo_inode *) (uintptr_t) ino;
+ struct lo_data *lo = lo_data(req);
+ struct lo_map_elem *elem;
+
+ pthread_mutex_lock(&lo->mutex);
+ elem = lo_map_get(&lo->ino_map, ino);
+ pthread_mutex_unlock(&lo->mutex);
+
+ if (!elem)
+ return NULL;
+
+ return elem->inode;
}
static int lo_fd(fuse_req_t req, fuse_ino_t ino)
{
- return lo_inode(req, ino)->fd;
+ struct lo_inode *inode = lo_inode(req, ino);
+ return inode ? inode->fd : -1;
}
static bool lo_debug(fuse_req_t req)
@@ -330,10 +353,18 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino,
struct stat *attr,
{
int saverr;
char procname[64];
- struct lo_inode *inode = lo_inode(req, ino);
- int ifd = inode->fd;
+ struct lo_inode *inode;
+ int ifd;
int res;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
+ ifd = inode->fd;
+
if (valid & FUSE_SET_ATTR_MODE) {
if (fi) {
res = fchmod(fi->fh, attr->st_mode);
@@ -456,6 +487,7 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent,
const char *name,
inode->dev = e->attr.st_dev;
pthread_mutex_lock(&lo->mutex);
+ inode->fuse_ino = lo_add_inode_mapping(req, inode);
prev = &lo->root;
next = prev->next;
next->prev = inode;
@@ -464,7 +496,7 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent,
const char *name,
prev->next = inode;
pthread_mutex_unlock(&lo->mutex);
}
- e->ino = (uintptr_t) inode;
+ e->ino = inode->fuse_ino;
if (lo_debug(req))
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n",
@@ -546,10 +578,16 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t
parent,
{
int res;
int saverr;
- struct lo_inode *dir = lo_inode(req, parent);
+ struct lo_inode *dir;
struct fuse_entry_param e;
struct lo_cred old = {};
+ dir = lo_inode(req, parent);
+ if (!dir) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
saverr = ENOMEM;
saverr = lo_change_cred(req, &old);
@@ -623,10 +661,16 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino,
fuse_ino_t parent,
{
int res;
struct lo_data *lo = lo_data(req);
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
struct fuse_entry_param e;
int saverr;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
memset(&e, 0, sizeof(struct fuse_entry_param));
e.attr_timeout = lo->timeout;
e.entry_timeout = lo->timeout;
@@ -642,7 +686,7 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino,
fuse_ino_t parent,
pthread_mutex_lock(&lo->mutex);
inode->refcount++;
pthread_mutex_unlock(&lo->mutex);
- e.ino = (uintptr_t) inode;
+ e.ino = inode->fuse_ino;
if (lo_debug(req))
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n",
@@ -708,10 +752,10 @@ static void unref_inode(struct lo_data *lo, struct
lo_inode *inode, uint64_t n)
next->prev = prev;
prev->next = next;
+ lo_map_remove(&lo->ino_map, inode->fuse_ino);
pthread_mutex_unlock(&lo->mutex);
close(inode->fd);
free(inode);
-
} else {
pthread_mutex_unlock(&lo->mutex);
}
@@ -720,7 +764,11 @@ static void unref_inode(struct lo_data *lo, struct
lo_inode *inode, uint64_t n)
static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup)
{
struct lo_data *lo = lo_data(req);
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
+
+ inode = lo_inode(req, ino);
+ if (!inode)
+ return;
if (lo_debug(req)) {
fuse_log(FUSE_LOG_DEBUG, " forget %lli %lli -%lli\n",
@@ -1161,10 +1209,16 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino,
const char *name,
{
char *value = NULL;
char procname[64];
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
ssize_t ret;
int saverr;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
saverr = ENOSYS;
if (!lo_data(req)->xattr)
goto out;
@@ -1217,10 +1271,16 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t
ino, size_t size)
{
char *value = NULL;
char procname[64];
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
ssize_t ret;
int saverr;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
saverr = ENOSYS;
if (!lo_data(req)->xattr)
goto out;
@@ -1273,10 +1333,16 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino,
const char *name,
const char *value, size_t size, int flags)
{
char procname[64];
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
ssize_t ret;
int saverr;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
saverr = ENOSYS;
if (!lo_data(req)->xattr)
goto out;
@@ -1304,10 +1370,16 @@ out:
static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *name)
{
char procname[64];
- struct lo_inode *inode = lo_inode(req, ino);
+ struct lo_inode *inode;
ssize_t ret;
int saverr;
+ inode = lo_inode(req, ino);
+ if (!inode) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
saverr = ENOSYS;
if (!lo_data(req)->xattr)
goto out;
@@ -1411,6 +1483,7 @@ int main(int argc, char *argv[])
struct fuse_cmdline_opts opts;
struct lo_data lo = { .debug = 0,
.writeback = 0 };
+ struct lo_map_elem *root_elem;
int ret = -1;
/* Don't mask creation mode, kernel already did that */
@@ -1419,8 +1492,18 @@ int main(int argc, char *argv[])
pthread_mutex_init(&lo.mutex, NULL);
lo.root.next = lo.root.prev = &lo.root;
lo.root.fd = -1;
+ lo.root.fuse_ino = FUSE_ROOT_ID;
lo.cache = CACHE_NORMAL;
+ /* Set up the ino map like this:
+ * [0] Reserved (will not be used)
+ * [1] Root inode
+ */
+ lo_map_init(&lo.ino_map);
+ lo_map_reserve(&lo.ino_map, 0)->in_use = false;
+ root_elem = lo_map_reserve(&lo.ino_map, lo.root.fuse_ino);
+ root_elem->inode = &lo.root;
+
if (fuse_parse_cmdline(&args, &opts) != 0)
return 1;
if (opts.show_help) {
@@ -1514,6 +1597,8 @@ err_out2:
err_out1:
fuse_opt_free_args(&args);
+ lo_map_destroy(&lo.ino_map);
+
if (lo.root.fd >= 0)
close(lo.root.fd);
--
2.23.0
