From 474d0adafed4d73720d6413b2903d6c4b529e5e6 Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Mon, 27 Jan 2020 19:01:15 +0100
Subject: [PATCH 044/116] virtiofsd: passthrough_ll: add dirp_map to hide
lo_dirp pointers
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RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20200127190227.40942-41-dgilbert@redhat.com>
Patchwork-id: 93495
O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 040/112] virtiofsd: passthrough_ll: add dirp_map to hide lo_dirp pointers
Bugzilla: 1694164
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>
From: Stefan Hajnoczi <stefanha@redhat.com>
Do not expose lo_dirp pointers to clients.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit b39bce121bfad8757eec0ee41f14607b883935d3)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
tools/virtiofsd/passthrough_ll.c | 103 +++++++++++++++++++++++++++++----------
1 file changed, 76 insertions(+), 27 deletions(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index a3ebf74..5f5a72f 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -56,27 +56,10 @@
#include "passthrough_helpers.h"
-/*
- * We are re-using pointers to our `struct lo_inode`
- * 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;
@@ -123,6 +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[] = {
@@ -253,6 +237,20 @@ static void lo_map_remove(struct lo_map *map, size_t 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)
{
struct lo_map_elem *elem;
@@ -861,9 +859,19 @@ 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,
@@ -873,6 +881,7 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino,
struct lo_data *lo = lo_data(req);
struct lo_dirp *d;
int fd;
+ ssize_t fh;
d = calloc(1, sizeof(struct lo_dirp));
if (d == NULL) {
@@ -892,7 +901,14 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino,
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;
}
@@ -903,6 +919,9 @@ out_errno:
error = errno;
out_err:
if (d) {
+ if (d->dp) {
+ closedir(d->dp);
+ }
if (fd != -1) {
close(fd);
}
@@ -920,17 +939,21 @@ 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;
goto error;
}
p = buf;
@@ -1028,8 +1051,21 @@ 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);
@@ -1081,8 +1117,18 @@ 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 {
@@ -1614,6 +1660,8 @@ 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;
}
@@ -1710,6 +1758,7 @@ 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) {
--
1.8.3.1