fs: new cont helpers
Rework the generic block "cont" routines to handle the new aops. Supporting
cont_prepare_write would take quite a lot of code to support, so remove it
instead (and we later convert all filesystems to use it).
write_begin gets passed AOP_FLAG_CONT_EXPAND when called from
generic_cont_expand, so filesystems can avoid the old hacks they used.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index ca04226..195339b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1684,6 +1684,7 @@
return copied;
}
+EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
/*
* This has the same sideeffects and return value as
@@ -1710,6 +1711,7 @@
kunmap(page);
return copied;
}
+EXPORT_SYMBOL(iov_iter_copy_from_user);
static void __iov_iter_advance_iov(struct iov_iter *i, size_t bytes)
{
@@ -1741,6 +1743,7 @@
__iov_iter_advance_iov(i, bytes);
i->count -= bytes;
}
+EXPORT_SYMBOL(iov_iter_advance);
/*
* Fault in the first iovec of the given iov_iter, to a maximum length
@@ -1757,6 +1760,7 @@
bytes = min(bytes, i->iov->iov_len - i->iov_offset);
return fault_in_pages_readable(buf, bytes);
}
+EXPORT_SYMBOL(iov_iter_fault_in_readable);
/*
* Return the count of just the current iov_iter segment.
@@ -1769,6 +1773,7 @@
else
return min(i->count, iov->iov_len - i->iov_offset);
}
+EXPORT_SYMBOL(iov_iter_single_seg_count);
/*
* Performs necessary checks before doing a write