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>

1 files changed, 15 insertions, 25 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b0b8fa0efba3..c8386f1961f0 100644
--- 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);