[PATCH v2 2/7] virtiofds: Changed allocations of iovec to GLib's functions

[Mahmoud Mandour <ma.mandourr@gmail.com>]

Replaced the calls to malloc()/calloc() and their respective
calls to free() of iovec structs with GLib's allocation and
deallocation functions.

Also, in one instance, used g_new0() instead of a calloc() call plus
a null-checking assertion.

iovec structs were created locally and freed as the function
ends. Hence, I used g_autofree and removed the respective calls to
free().

In one instance, a struct fuse_ioctl_iovec pointer is returned from a
function, namely, fuse_ioctl_iovec_copy. There, I used g_steal_pointer()
in conjunction with g_autofree, this gives the ownership of the pointer
to the calling function and still auto-frees the memory when the calling
function finishes (maintaining the symantics of previous code).

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tools/virtiofsd/fuse_lowlevel.c | 19 +++++++------------
 tools/virtiofsd/fuse_virtio.c   |  6 +-----
 2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 812cef6ef6..f965299ad9 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -217,9 +217,9 @@ static int send_reply(fuse_req_t req, int error, const void *arg,
 int fuse_reply_iov(fuse_req_t req, const struct iovec *iov, int count)
 {
     int res;
-    struct iovec *padded_iov;
+    g_autofree struct iovec *padded_iov;
 
-    padded_iov = malloc((count + 1) * sizeof(struct iovec));
+    padded_iov = g_try_new(struct iovec, count + 1);
     if (padded_iov == NULL) {
         return fuse_reply_err(req, ENOMEM);
     }
@@ -228,7 +228,6 @@ int fuse_reply_iov(fuse_req_t req, const struct iovec *iov, int count)
     count++;
 
     res = send_reply_iov(req, 0, padded_iov, count);
-    free(padded_iov);
 
     return res;
 }
@@ -565,10 +564,10 @@ int fuse_reply_bmap(fuse_req_t req, uint64_t idx)
 static struct fuse_ioctl_iovec *fuse_ioctl_iovec_copy(const struct iovec *iov,
                                                       size_t count)
 {
-    struct fuse_ioctl_iovec *fiov;
+    g_autofree struct fuse_ioctl_iovec *fiov;
     size_t i;
 
-    fiov = malloc(sizeof(fiov[0]) * count);
+    fiov = g_try_new(fuse_ioctl_iovec, count);
     if (!fiov) {
         return NULL;
     }
@@ -578,7 +577,7 @@ static struct fuse_ioctl_iovec *fuse_ioctl_iovec_copy(const struct iovec *iov,
         fiov[i].len = iov[i].iov_len;
     }
 
-    return fiov;
+    return g_steal_pointer(&fiov);
 }
 
 int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
@@ -629,9 +628,6 @@ int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
 
     res = send_reply_iov(req, 0, iov, count);
 out:
-    free(in_fiov);
-    free(out_fiov);
-
     return res;
 
 enomem:
@@ -663,11 +659,11 @@ int fuse_reply_ioctl(fuse_req_t req, int result, const void *buf, size_t size)
 int fuse_reply_ioctl_iov(fuse_req_t req, int result, const struct iovec *iov,
                          int count)
 {
-    struct iovec *padded_iov;
+    g_autofree struct iovec *padded_iov;
     struct fuse_ioctl_out arg;
     int res;
 
-    padded_iov = malloc((count + 2) * sizeof(struct iovec));
+    padded_iov = g_try_new(struct iovec, count + 2);
     if (padded_iov == NULL) {
         return fuse_reply_err(req, ENOMEM);
     }
@@ -680,7 +676,6 @@ int fuse_reply_ioctl_iov(fuse_req_t req, int result, const struct iovec *iov,
     memcpy(&padded_iov[2], iov, count * sizeof(struct iovec));
 
     res = send_reply_iov(req, 0, padded_iov, count + 2);
-    free(padded_iov);
 
     return res;
 }
diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
index 3e13997406..07e5d91a9f 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -347,8 +347,7 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
      * Build a copy of the the in_sg iov so we can skip bits in it,
      * including changing the offsets
      */
-    struct iovec *in_sg_cpy = calloc(sizeof(struct iovec), in_num);
-    assert(in_sg_cpy);
+    g_autofree struct iovec *in_sg_cpy = g_new0(struct iovec, in_num);
     memcpy(in_sg_cpy, in_sg, sizeof(struct iovec) * in_num);
     /* These get updated as we skip */
     struct iovec *in_sg_ptr = in_sg_cpy;
@@ -386,7 +385,6 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
             ret = errno;
             fuse_log(FUSE_LOG_DEBUG, "%s: preadv failed (%m) len=%zd\n",
                      __func__, len);
-            free(in_sg_cpy);
             goto err;
         }
         fuse_log(FUSE_LOG_DEBUG, "%s: preadv ret=%d len=%zd\n", __func__,
@@ -410,13 +408,11 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
         if (ret != len) {
             fuse_log(FUSE_LOG_DEBUG, "%s: ret!=len\n", __func__);
             ret = EIO;
-            free(in_sg_cpy);
             goto err;
         }
         in_sg_left -= ret;
         len -= ret;
     } while (in_sg_left);
-    free(in_sg_cpy);
 
     /* Need to fix out->len on EOF */
     if (len) {
-- 
2.25.1