[2/4] I/OAT: fix dma_pin_iovec_pages() error handling

Error handling needs to be modified in dma_pin_iovec_pages().
It should return NULL instead of ERR_PTR
(pinned_list is checked for NULL in tcp_recvmsg() to determine
if iovec pages have been successfully pinned down).
In case of error for the first iovec,
local_list->nr_iovecs needs to be initialized.

Cc: <stable@kernel.org>
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/dma/iovlock.c b/drivers/dma/iovlock.c
index e763d72..9f6fe46 100644 (file)
--- a/drivers/dma/iovlock.c
+++ b/drivers/dma/iovlock.c
@@ -55,7 +55,6 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
        int nr_iovecs = 0;
        int iovec_len_used = 0;
        int iovec_pages_used = 0;
-       long err;
 
        /* don't pin down non-user-based iovecs */
        if (segment_eq(get_fs(), KERNEL_DS))
@@ -72,23 +71,21 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
        local_list = kmalloc(sizeof(*local_list)
                + (nr_iovecs * sizeof (struct dma_page_list))
                + (iovec_pages_used * sizeof (struct page*)), GFP_KERNEL);
-       if (!local_list) {
-               err = -ENOMEM;
+       if (!local_list)
                goto out;
-       }
 
        /* list of pages starts right after the page list array */
        pages = (struct page **) &local_list->page_list[nr_iovecs];
 
+       local_list->nr_iovecs = 0;
+
        for (i = 0; i < nr_iovecs; i++) {
                struct dma_page_list *page_list = &local_list->page_list[i];
 
                len -= iov[i].iov_len;
 
-               if (!access_ok(VERIFY_WRITE, iov[i].iov_base, iov[i].iov_len)) {
-                       err = -EFAULT;
+               if (!access_ok(VERIFY_WRITE, iov[i].iov_base, iov[i].iov_len))
                        goto unpin;
-               }
 
                page_list->nr_pages = num_pages_spanned(&iov[i]);
                page_list->base_address = iov[i].iov_base;
@@ -109,10 +106,8 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
                        NULL);
                up_read(&current->mm->mmap_sem);
 
-               if (ret != page_list->nr_pages) {
-                       err = -ENOMEM;
+               if (ret != page_list->nr_pages)
                        goto unpin;
-               }
 
                local_list->nr_iovecs = i + 1;
        }
@@ -122,7 +117,7 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
 unpin:
        dma_unpin_iovec_pages(local_list);
 out:
-       return ERR_PTR(err);
+       return NULL;
 }
 
 void dma_unpin_iovec_pages(struct dma_pinned_list *pinned_list)