From: Dave Kleikamp <dave.kleikamp@oracle.com>
Date: Wed, 20 Jun 2012 21:05:59 +0000 (-0500)
Subject: ocfs2:btrfs: aio-dio-loop changes broke setrlimit behavior [orabug 14207636]
X-Git-Tag: v2.6.39-400.9.0~516^2~8^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2877d364d6e8070595b0c99efa6333309fc7bffd;p=users%2Fjedix%2Flinux-maple.git

ocfs2:btrfs: aio-dio-loop changes broke setrlimit behavior [orabug 14207636]

The aio-dio changes for the loop device driver broke ocfs2 and btrfs's
handling of rlimit. generic_write_checks() adjusts the IO byte count to
account for the rlimit, but the updated count was not being reflected in
the iov_iter data structure.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 0afdb8f81a20..a458d1397e28 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1338,13 +1338,13 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	u64 start_pos;
 	ssize_t num_written = 0;
 	ssize_t err = 0;
-	size_t count;
+	size_t count, ocount;
 
 	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 
 	mutex_lock(&inode->i_mutex);
 
-	count = iov_iter_count(iter);
+	ocount = count = iov_iter_count(iter);
 
 	current->backing_dev_info = inode->i_mapping->backing_dev_info;
 	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -1396,6 +1396,9 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 		num_written = __btrfs_direct_write(iocb, iter, pos, ppos,
 						   count);
 	} else {
+		if (count != ocount)
+			iov_iter_shorten(iter, count);
+
 		num_written = __btrfs_buffered_write(file, iter, pos);
 		if (num_written > 0)
 			*ppos = pos + num_written;
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 87bcf38dfa21..2df0c6392348 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2223,7 +2223,7 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
 	int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
 	int can_do_direct, has_refcount = 0;
 	ssize_t written = 0;
-	size_t count;		/* after file limit checks */
+	size_t count, ocount;
 	loff_t old_size, *ppos = &iocb->ki_pos;
 	u32 old_clusters;
 	struct file *file = iocb->ki_filp;
@@ -2352,7 +2352,7 @@ relock:
 	ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
 
-	count = iov_iter_count(iter);
+	ocount = count = iov_iter_count(iter);
 	ret = generic_write_checks(file, ppos, &count,
 				   S_ISBLK(inode->i_mode));
 	if (ret)
@@ -2366,6 +2366,9 @@ relock:
 			goto out_dio;
 		}
 	} else {
+		if (count != ocount)
+			iov_iter_shorten(iter, count);
+
 		current->backing_dev_info = file->f_mapping->backing_dev_info;
 		written = generic_file_buffered_write_iter(iocb, iter, *ppos,
 							   ppos, 0);
diff --git a/mm/iov-iter.c b/mm/iov-iter.c
index 5a0b94951d87..5006cdbfb5dc 100644
--- a/mm/iov-iter.c
+++ b/mm/iov-iter.c
@@ -358,6 +358,7 @@ static int ii_iovec_shorten(struct iov_iter *i, size_t count)
 {
 	struct iovec *iov = (struct iovec *)i->data;
 	i->nr_segs = iov_shorten(iov, i->nr_segs, count);
+	i->count = count;
 	return 0;
 }