[v3,2/7] virtiofsd: Changed allocations of iovec to GLib's functions

Commit Message

Mahmoud Abumandour April 27, 2021, 6:13 p.m. UTC

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

Replaced the allocation of in_sg_cpy to g_new() instead of a call
to calloc() and a null-checking assertion. Not g_new0()
because the buffer is immediately overwritten using memcpy.

Signed-off-by: Mahmoud Mandour <[e-mail]>
---
v2 -> v3:
    * Removed a wrongful combination of g_autofree and g_steel_pointer().
    * Removed some goto paths that IMHO were not so useful any more.
    * In v2, I allocated in_sg_cpy through g_new0(). This patch, I use
      g_new() because the buffer is memcpy'd into right away so no need
      to zero-initialize.
    * Moved the declaration of in_sg_cpy to the top of the function
      to match QEMU's style guidelines. 

 tools/virtiofsd/fuse_lowlevel.c | 31 ++++++++++++-------------------
 tools/virtiofsd/fuse_virtio.c   |  8 +++-----
 2 files changed, 15 insertions(+), 24 deletions(-)

Comments

Dr. David Alan Gilbert May 6, 2021, 9:39 a.m. UTC | #1

* Mahmoud Mandour ([e-mail]) wrote:
> Replaced the calls to malloc()/calloc() and their respective
> calls to free() of iovec structs with GLib's allocation and
> deallocation functions and used g_autofree when appropriate.
> 
> Replaced the allocation of in_sg_cpy to g_new() instead of a call
> to calloc() and a null-checking assertion. Not g_new0()
> because the buffer is immediately overwritten using memcpy.
> 
> Signed-off-by: Mahmoud Mandour <[e-mail]>

Thanks,


Reviewed-by: Dr. David Alan Gilbert <[e-mail]>

> ---
> v2 -> v3:
>     * Removed a wrongful combination of g_autofree and g_steel_pointer().
>     * Removed some goto paths that IMHO were not so useful any more.
>     * In v2, I allocated in_sg_cpy through g_new0(). This patch, I use
>       g_new() because the buffer is memcpy'd into right away so no need
>       to zero-initialize.
>     * Moved the declaration of in_sg_cpy to the top of the function
>       to match QEMU's style guidelines. 
> 
>  tools/virtiofsd/fuse_lowlevel.c | 31 ++++++++++++-------------------
>  tools/virtiofsd/fuse_virtio.c   |  8 +++-----
>  2 files changed, 15 insertions(+), 24 deletions(-)
> 
> diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
> index c8bea246ab..7fe2cef1eb 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 = NULL;
>  
> -    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;
>  }
> @@ -568,7 +567,7 @@ static struct fuse_ioctl_iovec *fuse_ioctl_iovec_copy(const struct iovec *iov,
>      struct fuse_ioctl_iovec *fiov;
>      size_t i;
>  
> -    fiov = malloc(sizeof(fiov[0]) * count);
> +    fiov = g_try_new(struct fuse_ioctl_iovec, count);
>      if (!fiov) {
>          return NULL;
>      }
> @@ -586,8 +585,8 @@ int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
>                             size_t out_count)
>  {
>      struct fuse_ioctl_out arg;
> -    struct fuse_ioctl_iovec *in_fiov = NULL;
> -    struct fuse_ioctl_iovec *out_fiov = NULL;
> +    g_autofree struct fuse_ioctl_iovec *in_fiov = NULL;
> +    g_autofree struct fuse_ioctl_iovec *out_fiov = NULL;
>      struct iovec iov[4];
>      size_t count = 1;
>      int res;
> @@ -603,13 +602,14 @@ int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
>      /* Can't handle non-compat 64bit ioctls on 32bit */
>      if (sizeof(void *) == 4 && req->ioctl_64bit) {
>          res = fuse_reply_err(req, EINVAL);
> -        goto out;
> +        return res;
>      }
>  
>      if (in_count) {
>          in_fiov = fuse_ioctl_iovec_copy(in_iov, in_count);
>          if (!in_fiov) {
> -            goto enomem;
> +            res = fuse_reply_err(req, ENOMEM);
> +            return res;

That could have just been return fuse_reply_err(req, ENOMEM);
but that's minor.

Dave

>          }
>  
>          iov[count].iov_base = (void *)in_fiov;
> @@ -619,7 +619,8 @@ int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
>      if (out_count) {
>          out_fiov = fuse_ioctl_iovec_copy(out_iov, out_count);
>          if (!out_fiov) {
> -            goto enomem;
> +            res = fuse_reply_err(req, ENOMEM);
> +            return res;
>          }
>  
>          iov[count].iov_base = (void *)out_fiov;
> @@ -628,15 +629,8 @@ 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:
> -    res = fuse_reply_err(req, ENOMEM);
> -    goto out;
>  }
>  
>  int fuse_reply_ioctl(fuse_req_t req, int result, const void *buf, size_t size)
> @@ -663,11 +657,11 @@ 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 = NULL;
>      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 +674,6 @@ 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 9e437618fb..9b00687cb0 100644
> --- a/tools/virtiofsd/fuse_virtio.c
> +++ b/tools/virtiofsd/fuse_virtio.c
> @@ -295,6 +295,8 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
>      VuVirtqElement *elem = &req->elem;
>      int ret = 0;
>  
> +    g_autofree struct iovec *in_sg_cpy = NULL;
> +
>      assert(count >= 1);
>      assert(iov[0].iov_len >= sizeof(struct fuse_out_header));
>  
> @@ -347,8 +349,7 @@ 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);
> +    in_sg_cpy = g_new(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 +387,6 @@ 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 +410,11 @@ 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
>

Patch

diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index c8bea246ab..7fe2cef1eb 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 = NULL;
 
-    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;
 }
@@ -568,7 +567,7 @@  static struct fuse_ioctl_iovec *fuse_ioctl_iovec_copy(const struct iovec *iov,
     struct fuse_ioctl_iovec *fiov;
     size_t i;
 
-    fiov = malloc(sizeof(fiov[0]) * count);
+    fiov = g_try_new(struct fuse_ioctl_iovec, count);
     if (!fiov) {
         return NULL;
     }
@@ -586,8 +585,8 @@  int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
                            size_t out_count)
 {
     struct fuse_ioctl_out arg;
-    struct fuse_ioctl_iovec *in_fiov = NULL;
-    struct fuse_ioctl_iovec *out_fiov = NULL;
+    g_autofree struct fuse_ioctl_iovec *in_fiov = NULL;
+    g_autofree struct fuse_ioctl_iovec *out_fiov = NULL;
     struct iovec iov[4];
     size_t count = 1;
     int res;
@@ -603,13 +602,14 @@  int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
     /* Can't handle non-compat 64bit ioctls on 32bit */
     if (sizeof(void *) == 4 && req->ioctl_64bit) {
         res = fuse_reply_err(req, EINVAL);
-        goto out;
+        return res;
     }
 
     if (in_count) {
         in_fiov = fuse_ioctl_iovec_copy(in_iov, in_count);
         if (!in_fiov) {
-            goto enomem;
+            res = fuse_reply_err(req, ENOMEM);
+            return res;
         }
 
         iov[count].iov_base = (void *)in_fiov;
@@ -619,7 +619,8 @@  int fuse_reply_ioctl_retry(fuse_req_t req, const struct iovec *in_iov,
     if (out_count) {
         out_fiov = fuse_ioctl_iovec_copy(out_iov, out_count);
         if (!out_fiov) {
-            goto enomem;
+            res = fuse_reply_err(req, ENOMEM);
+            return res;
         }
 
         iov[count].iov_base = (void *)out_fiov;
@@ -628,15 +629,8 @@  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:
-    res = fuse_reply_err(req, ENOMEM);
-    goto out;
 }
 
 int fuse_reply_ioctl(fuse_req_t req, int result, const void *buf, size_t size)
@@ -663,11 +657,11 @@  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 = NULL;
     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 +674,6 @@  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 9e437618fb..9b00687cb0 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -295,6 +295,8 @@  int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
     VuVirtqElement *elem = &req->elem;
     int ret = 0;
 
+    g_autofree struct iovec *in_sg_cpy = NULL;
+
     assert(count >= 1);
     assert(iov[0].iov_len >= sizeof(struct fuse_out_header));
 
@@ -347,8 +349,7 @@  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);
+    in_sg_cpy = g_new(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 +387,6 @@  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 +410,11 @@  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) {