iov_iter_truncate()
Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.
Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/filemap.c b/mm/filemap.c
index 3aeaf2d..c0404b7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2345,8 +2345,7 @@
EXPORT_SYMBOL(pagecache_write_end);
ssize_t
-generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
- loff_t pos, size_t count, size_t ocount)
+generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
@@ -2356,10 +2355,7 @@
pgoff_t end;
struct iov_iter data;
- if (count != ocount)
- from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count);
-
- write_len = iov_length(from->iov, from->nr_segs);
+ write_len = iov_iter_count(from);
end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
@@ -2568,7 +2564,6 @@
{
struct file *file = iocb->ki_filp;
struct address_space * mapping = file->f_mapping;
- size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
loff_t pos = iocb->ki_pos;
@@ -2577,7 +2572,8 @@
ssize_t status;
struct iov_iter from;
- count = ocount = iov_length(iov, nr_segs);
+ count = iov_length(iov, nr_segs);
+ iov_iter_init(&from, WRITE, iov, nr_segs, count);
/* We can write back this queue in page reclaim */
current->backing_dev_info = mapping->backing_dev_info;
@@ -2588,6 +2584,8 @@
if (count == 0)
goto out;
+ iov_iter_truncate(&from, count);
+
err = file_remove_suid(file);
if (err)
goto out;
@@ -2596,14 +2594,11 @@
if (err)
goto out;
- iov_iter_init(&from, WRITE, iov, nr_segs, count);
-
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (unlikely(file->f_flags & O_DIRECT)) {
loff_t endbyte;
- written = generic_file_direct_write(iocb, &from, pos,
- count, ocount);
+ written = generic_file_direct_write(iocb, &from, pos);
if (written < 0 || written == count)
goto out;