btrfs: switch check_direct_IO() to iov_iter

... and don't open-code iov_iter_alignment() there

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b0b8fa0efba3f32c8b90d129ef3be884b3eb46d0..c8386f1961f001586f5f1824e7e02d1b63bf4470 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7391,39 +7391,30 @@ free_ordered:
 }
 
 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
-                       const struct iovec *iov, loff_t offset,
-                       unsigned long nr_segs)
+                       const struct iov_iter *iter, loff_t offset)
 {
        int seg;
        int i;
-       size_t size;
-       unsigned long addr;
        unsigned blocksize_mask = root->sectorsize - 1;
        ssize_t retval = -EINVAL;
-       loff_t end = offset;
 
        if (offset & blocksize_mask)
                goto out;
 
-       /* Check the memory alignment.  Blocks cannot straddle pages */
-       for (seg = 0; seg < nr_segs; seg++) {
-               addr = (unsigned long)iov[seg].iov_base;
-               size = iov[seg].iov_len;
-               end += size;
-               if ((addr & blocksize_mask) || (size & blocksize_mask))
-                       goto out;
-
-               /* If this is a write we don't need to check anymore */
-               if (rw & WRITE)
-                       continue;
+       if (iov_iter_alignment(iter) & blocksize_mask)
+               goto out;
 
-               /*
-                * Check to make sure we don't have duplicate iov_base's in this
-                * iovec, if so return EINVAL, otherwise we'll get csum errors
-                * when reading back.
-                */
-               for (i = seg + 1; i < nr_segs; i++) {
-                       if (iov[seg].iov_base == iov[i].iov_base)
+       /* If this is a write we don't need to check anymore */
+       if (rw & WRITE)
+               return 0;
+       /*
+        * Check to make sure we don't have duplicate iov_base's in this
+        * iovec, if so return EINVAL, otherwise we'll get csum errors
+        * when reading back.
+        */
+       for (seg = 0; seg < iter->nr_segs; seg++) {
+               for (i = seg + 1; i < iter->nr_segs; i++) {
+                       if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
                                goto out;
                }
        }
@@ -7443,8 +7434,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
        bool relock = false;
        ssize_t ret;
 
-       if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iter->iov,
-                           offset, iter->nr_segs))
+       if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iter, offset))
                return 0;
 
        atomic_inc(&inode->i_dio_count);