xfs: do not require an ioend for new EOF calculation

Replace xfs_ioend_new_eof with a new inline xfs_new_eof helper that
doesn't require and ioend, and is available also outside of xfs_aops.c.

Also make the code a bit more clear by using a normal if statement
instead of a slightly misleading MIN().
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/xfs_aops.c

@@ -98,23 +98,6 @@ xfs_destroy_ioend(
 	mempool_free(ioend, xfs_ioend_pool);
 }
 
-/*
- * If the end of the current ioend is beyond the current EOF,
- * return the new EOF value, otherwise zero.
- */
-STATIC xfs_fsize_t
-xfs_ioend_new_eof(
-	xfs_ioend_t		*ioend)
-{
-	xfs_inode_t		*ip = XFS_I(ioend->io_inode);
-	xfs_fsize_t		isize;
-	xfs_fsize_t		bsize;
-
-	bsize = ioend->io_offset + ioend->io_size;
-	isize = MIN(i_size_read(VFS_I(ip)), bsize);
-	return isize > ip->i_d.di_size ? isize : 0;
-}
-
 /*
  * Fast and loose check if this write could update the on-disk inode size.
  */
@@ -135,7 +118,7 @@ xfs_setfilesize(
 	xfs_fsize_t		isize;
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
-	isize = xfs_ioend_new_eof(ioend);
+	isize = xfs_new_eof(ip, ioend->io_offset + ioend->io_size);
 	if (isize) {
 		trace_xfs_setfilesize(ip, ioend->io_offset, ioend->io_size);
 		ip->i_d.di_size = isize;
@@ -357,6 +340,7 @@ xfs_submit_ioend_bio(
 	xfs_ioend_t		*ioend,
 	struct bio		*bio)
 {
+	struct xfs_inode	*ip = XFS_I(ioend->io_inode);
 	atomic_inc(&ioend->io_remaining);
 	bio->bi_private = ioend;
 	bio->bi_end_io = xfs_end_bio;
@@ -365,8 +349,8 @@ xfs_submit_ioend_bio(
 	 * If the I/O is beyond EOF we mark the inode dirty immediately
 	 * but don't update the inode size until I/O completion.
 	 */
-	if (xfs_ioend_new_eof(ioend))
-		xfs_mark_inode_dirty(XFS_I(ioend->io_inode));
+	if (xfs_new_eof(ip, ioend->io_offset + ioend->io_size))
+		xfs_mark_inode_dirty(ip);
 
 	submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE, bio);
 }

fs/xfs/xfs_inode.h

@@ -274,6 +274,20 @@ static inline xfs_fsize_t XFS_ISIZE(struct xfs_inode *ip)
 	return ip->i_d.di_size;
 }
 
+/*
+ * If this I/O goes past the on-disk inode size update it unless it would
+ * be past the current in-core inode size.
+ */
+static inline xfs_fsize_t
+xfs_new_eof(struct xfs_inode *ip, xfs_fsize_t new_size)
+{
+	xfs_fsize_t i_size = i_size_read(VFS_I(ip));
+
+	if (new_size > i_size)
+		new_size = i_size;
+	return new_size > ip->i_d.di_size ? new_size : 0;
+}
+
 /*
  * i_flags helper functions
  */