From: Stefan Hajnoczi <stefa...@redhat.com>
Do not expose lo_dirp pointers to clients.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
contrib/virtiofsd/passthrough_ll.c | 100 +++++++++++++++++++++--------
1 file changed, 75 insertions(+), 25 deletions(-)
diff --git a/contrib/virtiofsd/passthrough_ll.c
b/contrib/virtiofsd/passthrough_ll.c
index f718c951f7..9f82166079 100644
--- a/contrib/virtiofsd/passthrough_ll.c
+++ b/contrib/virtiofsd/passthrough_ll.c
@@ -56,22 +56,10 @@
#define HAVE_POSIX_FALLOCATE 1
-/* 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
-_Static_assert(sizeof(fuse_ino_t) >= sizeof(uintptr_t),
- "fuse_ino_t too small to hold uintptr_t values!");
-#else
-struct _uintptr_to_must_hold_fuse_ino_t_dummy_struct \
- { unsigned _uintptr_to_must_hold_fuse_ino_t:
- ((sizeof(fuse_ino_t) >= sizeof(uintptr_t)) ? 1 : -1); };
-#endif
-
struct lo_map_elem {
union {
struct lo_inode *inode;
+ struct lo_dirp *dirp;
ssize_t freelist;
};
bool in_use;
@@ -118,6 +106,7 @@ struct lo_data {
int timeout_set;
struct lo_inode root; /* protected by lo->mutex */
struct lo_map ino_map; /* protected by lo->mutex */
+ struct lo_map dirp_map; /* protected by lo->mutex */
};
static const struct fuse_opt lo_opts[] = {
@@ -252,6 +241,19 @@ 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_dirp_mapping(fuse_req_t req, struct lo_dirp *dirp)
+{
+ struct lo_map_elem *elem;
+
+ elem = lo_map_alloc_elem(&lo_data(req)->dirp_map);
+ if (!elem)
+ return -1;
+
+ elem->dirp = dirp;
+ return elem - lo_data(req)->dirp_map.elems;
+}
+
/* Assumes lo->mutex is held */
static ssize_t lo_add_inode_mapping(fuse_req_t req, struct lo_inode *inode)
{
@@ -820,16 +822,28 @@ struct lo_dirp {
off_t offset;
};
-static struct lo_dirp *lo_dirp(struct fuse_file_info *fi)
+static struct lo_dirp *lo_dirp(fuse_req_t req, struct fuse_file_info *fi)
{
- return (struct lo_dirp *) (uintptr_t) fi->fh;
+ struct lo_data *lo = lo_data(req);
+ struct lo_map_elem *elem;
+
+ pthread_mutex_lock(&lo->mutex);
+ elem = lo_map_get(&lo->dirp_map, fi->fh);
+ pthread_mutex_unlock(&lo->mutex);
+ if (!elem)
+ return NULL;
+
+ return elem->dirp;
}
static void lo_opendir(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info
*fi)
{
int error = ENOMEM;
struct lo_data *lo = lo_data(req);
- struct lo_dirp *d = calloc(1, sizeof(struct lo_dirp));
+ struct lo_dirp *d;
+ ssize_t fh;
+
+ d = calloc(1, sizeof(struct lo_dirp));
if (d == NULL)
goto out_err;
@@ -844,7 +858,13 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi
d->offset = 0;
d->entry = NULL;
- fi->fh = (uintptr_t) d;
+ pthread_mutex_lock(&lo->mutex);
+ fh = lo_add_dirp_mapping(req, d);
+ pthread_mutex_unlock(&lo->mutex);
+ if (fh == -1)
+ goto out_err;
+
+ fi->fh = fh;
if (lo->cache == CACHE_ALWAYS)
fi->keep_cache = 1;
fuse_reply_open(req, fi);
@@ -854,6 +874,8 @@ out_errno:
error = errno;
out_err:
if (d) {
+ if (d->dp)
+ closedir(d->dp);
if (d->fd != -1)
close(d->fd);
free(d);
@@ -870,19 +892,21 @@ static int is_dot_or_dotdot(const char *name)
static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
off_t offset, struct fuse_file_info *fi, int plus)
{
- struct lo_dirp *d = lo_dirp(fi);
- char *buf;
+ struct lo_dirp *d;
+ char *buf = NULL;
char *p;
size_t rem = size;
- int err;
+ int err = ENOMEM;
(void) ino;
+ d = lo_dirp(req, fi);
+ if (!d)
+ goto error;
+
buf = calloc(1, size);
- if (!buf) {
- err = ENOMEM;
+ if (!buf)
goto error;
- }
p = buf;
if (offset != d->offset) {
@@ -974,8 +998,21 @@ static void lo_readdirplus(fuse_req_t req, fuse_ino_t ino,
size_t size,
static void lo_releasedir(fuse_req_t req, fuse_ino_t ino, struct
fuse_file_info *fi)
{
- struct lo_dirp *d = lo_dirp(fi);
+ struct lo_data *lo = lo_data(req);
+ struct lo_dirp *d;
+
(void) ino;
+
+ d = lo_dirp(req, fi);
+ if (!d) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
+ pthread_mutex_lock(&lo->mutex);
+ lo_map_remove(&lo->dirp_map, fi->fh);
+ pthread_mutex_unlock(&lo->mutex);
+
closedir(d->dp);
free(d);
fuse_reply_err(req, 0);
@@ -1023,8 +1060,18 @@ static void lo_fsyncdir(fuse_req_t req, fuse_ino_t ino,
int datasync,
struct fuse_file_info *fi)
{
int res;
- int fd = dirfd(lo_dirp(fi)->dp);
+ struct lo_dirp *d;
+ int fd;
+
(void) ino;
+
+ d = lo_dirp(req, fi);
+ if (!d) {
+ fuse_reply_err(req, EBADF);
+ return;
+ }
+
+ fd = dirfd(d->dp);
if (datasync)
res = fdatasync(fd);
else
@@ -1504,6 +1551,8 @@ int main(int argc, char *argv[])
root_elem = lo_map_reserve(&lo.ino_map, lo.root.fuse_ino);
root_elem->inode = &lo.root;
+ lo_map_init(&lo.dirp_map);
+
if (fuse_parse_cmdline(&args, &opts) != 0)
return 1;
if (opts.show_help) {
@@ -1597,6 +1646,7 @@ err_out2:
err_out1:
fuse_opt_free_args(&args);
+ lo_map_destroy(&lo.dirp_map);
lo_map_destroy(&lo.ino_map);
if (lo.root.fd >= 0)
--
2.23.0
