orangefs: make wait_for_direct_io() take iov_iter

incidentally, insane or compromised server returning *more* than
requested on read should not oops the kernel - initialize the
iov_iter for read according to the iovec we've got.  That's why
pvfs_bufmap_copy_to_iovec() needed a separate size argument - we
shouldn't abuse iov_iter_count(iter) for passing that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index bd8e6f8660477d4d02e631815068b143a1000589..9a439b2e8bde32db429c945d915b9ac9fb1df690 100644 (file)
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -94,7 +94,7 @@ static int postcopy_buffers(struct pvfs2_bufmap *bufmap,
  * Post and wait for the I/O upcall to finish
  */
 static ssize_t wait_for_direct_io(enum PVFS_io_type type, struct inode *inode,
-               loff_t *offset, struct iovec *vec, unsigned long nr_segs,
+               loff_t *offset, struct iov_iter *iter,
                size_t total_size, loff_t readahead_size)
 {
        struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
@@ -137,10 +137,9 @@ populate_shared_memory:
        new_op->upcall.req.io.offset = *offset;
 
        gossip_debug(GOSSIP_FILE_DEBUG,
-                    "%s(%pU): nr_segs %lu, offset: %llu total_size: %zd\n",
+                    "%s(%pU): offset: %llu total_size: %zd\n",
                     __func__,
                     handle,
-                    nr_segs,
                     llu(*offset),
                     total_size);
        /*
@@ -148,11 +147,9 @@ populate_shared_memory:
         * precopy_buffers only pertains to writes.
         */
        if (type == PVFS_IO_WRITE) {
-               struct iov_iter iter;
-               iov_iter_init(&iter, WRITE, vec, nr_segs, total_size);
                ret = precopy_buffers(bufmap,
                                      buffer_index,
-                                     &iter,
+                                     iter,
                                      total_size);
                if (ret < 0)
                        goto out;
@@ -213,11 +210,9 @@ populate_shared_memory:
         * postcopy_buffers only pertains to reads.
         */
        if (type == PVFS_IO_READ) {
-               struct iov_iter iter;
-               iov_iter_init(&iter, READ, vec, nr_segs, new_op->downcall.resp.io.amt_complete);
                ret = postcopy_buffers(bufmap,
                                       buffer_index,
-                                      &iter,
+                                      iter,
                                       new_op->downcall.resp.io.amt_complete);
                if (ret < 0) {
                        /*
@@ -563,6 +558,7 @@ static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
 #endif
        seg = 0;
        while (total_count < count) {
+               struct iov_iter iter;
                size_t each_count;
                size_t amt_complete;
 
@@ -583,8 +579,11 @@ static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
                             handle,
                             (int)*offset);
 
-               ret = wait_for_direct_io(type, inode, offset, ptr,
-                               seg_array[seg], each_count, 0);
+               iov_iter_init(&iter, type == PVFS_IO_READ ? READ : WRITE,
+                             ptr, seg_array[seg], each_count);
+
+               ret = wait_for_direct_io(type, inode, offset, &iter,
+                               each_count, 0);
                gossip_debug(GOSSIP_FILE_DEBUG,
                             "%s(%pU): return from wait_for_io:%d\n",
                             __func__,
@@ -654,6 +653,7 @@ ssize_t pvfs2_inode_read(struct inode *inode,
        struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
        size_t bufmap_size;
        struct iovec vec;
+       struct iov_iter iter;
        ssize_t ret = -EINVAL;
 
        g_pvfs2_stats.reads++;
@@ -676,7 +676,8 @@ ssize_t pvfs2_inode_read(struct inode *inode,
                     count,
                     llu(*offset));
 
-       ret = wait_for_direct_io(PVFS_IO_READ, inode, offset, &vec, 1,
+       iov_iter_init(&iter, READ, &vec, 1, count);
+       ret = wait_for_direct_io(PVFS_IO_READ, inode, offset, &iter,
                        count, readahead_size);
        if (ret > 0)
                *offset += ret;