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Subject: [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t
From:   David Howells <dhowells@redhat.com>
To:     viro@zeniv.linux.org.uk
Cc:     dhowells@redhat.com, linux-fsdevel@vger.kernel.org,
        linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org
Date:   Thu, 13 Sep 2018 16:52:00 +0100
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Make count and iov_offset loff_t not size_t so that they can handle
transactions larger than 4GiB in size and starting at 4GiB or more into a
file on a 32-bit system.

On a 64-bit system, this should make no difference.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/btrfs/file.c     |    7 ++++---
 fs/nfs/direct.c     |    2 +-
 include/linux/uio.h |    4 ++--
 lib/iov_iter.c      |   14 +++++++-------
 net/9p/client.c     |    2 +-
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2be00e873e92..cdf3149a5871 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1596,9 +1596,10 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 	while (iov_iter_count(i) > 0) {
 		size_t offset = pos & (PAGE_SIZE - 1);
 		size_t sector_offset;
-		size_t write_bytes = min(iov_iter_count(i),
-					 nrptrs * (size_t)PAGE_SIZE -
-					 offset);
+		size_t write_bytes = min_t(size_t,
+					   iov_iter_count(i),
+					   nrptrs * (size_t)PAGE_SIZE -
+					   offset);
 		size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
 						PAGE_SIZE);
 		size_t reserve_bytes;
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index aa12c3063bae..6550e712b063 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -974,7 +974,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 	struct nfs_lock_context *l_ctx;
 	loff_t pos, end;
 
-	dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n",
+	dfprintk(FILE, "NFS: direct write(%pD2, %zu@%lld)\n",
 		file, iov_iter_count(iter), (long long) iocb->ki_pos);
 
 	result = generic_write_checks(iocb, iter);
diff --git a/include/linux/uio.h b/include/linux/uio.h
index d5f8755bf778..1e03cb50a0e0 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -31,7 +31,7 @@ enum iter_type {
 struct iov_iter {
 	enum iter_type iter_type:8;
 	u8 iter_dir;
-	size_t iov_offset;
+	loff_t iov_offset;
 	size_t count;
 	union {
 		const struct iovec *iov;
@@ -89,7 +89,7 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
 {
 	return (struct iovec) {
 		.iov_base = iter->iov->iov_base + iter->iov_offset,
-		.iov_len = min(iter->count,
+		.iov_len = min_t(size_t, iter->count,
 			       iter->iov->iov_len - iter->iov_offset),
 	};
 }
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f30ecd263d6e..8231f0e38f20 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -13,7 +13,7 @@
 	size_t left;					\
 	size_t wanted = n;				\
 	__p = i->iov;					\
-	__v.iov_len = min(n, __p->iov_len - skip);	\
+	__v.iov_len = min_t(size_t, n, __p->iov_len - skip);	\
 	if (likely(__v.iov_len)) {			\
 		__v.iov_base = __p->iov_base + skip;	\
 		left = (STEP);				\
@@ -40,7 +40,7 @@
 #define iterate_kvec(i, n, __v, __p, skip, STEP) {	\
 	size_t wanted = n;				\
 	__p = i->kvec;					\
-	__v.iov_len = min(n, __p->iov_len - skip);	\
+	__v.iov_len = min_t(size_t, n, __p->iov_len - skip);	\
 	if (likely(__v.iov_len)) {			\
 		__v.iov_base = __p->iov_base + skip;	\
 		(void)(STEP);				\
@@ -74,7 +74,7 @@
 
 #define iterate_all_kinds(i, n, v, I, B, K) {			\
 	if (likely(n)) {					\
-		size_t skip = i->iov_offset;			\
+		loff_t skip = i->iov_offset;			\
 		switch (iov_iter_type(i)) {			\
 		case ITER_BVEC: {				\
 			struct bio_vec v;			\
@@ -105,7 +105,7 @@
 	if (unlikely(i->count < n))				\
 		n = i->count;					\
 	if (i->count) {						\
-		size_t skip = i->iov_offset;			\
+		loff_t skip = i->iov_offset;			\
 		switch (iov_iter_type(i)) {			\
 		case ITER_BVEC: {				\
 			const struct bio_vec *bvec = i->bvec;	\
@@ -358,7 +358,7 @@ static bool sanity(const struct iov_iter *i)
 	}
 	return true;
 Bad:
-	printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset);
+	printk(KERN_ERR "idx = %d, offset = %lld\n", i->idx, i->iov_offset);
 	printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n",
 			pipe->curbuf, pipe->nrbufs, pipe->buffers);
 	for (idx = 0; idx < pipe->buffers; idx++)
@@ -1105,10 +1105,10 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
 	case ITER_PIPE:
 		return i->count;	// it is a silly place, anyway
 	case ITER_BVEC:
-		return min(i->count, i->bvec->bv_len - i->iov_offset);
+		return min_t(size_t, i->count, i->bvec->bv_len - i->iov_offset);
 	case ITER_KVEC:
 	case ITER_IOVEC:
-		return min(i->count, i->iov->iov_len - i->iov_offset);
+		return min_t(size_t, i->count, i->iov->iov_len - i->iov_offset);
 	}
 	BUG();
 }
diff --git a/net/9p/client.c b/net/9p/client.c
index a9cd1401bd09..10f74bd027dd 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1631,7 +1631,7 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
 	int total = 0;
 	*err = 0;
 
-	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
+	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zu\n",
 				fid->fid, (unsigned long long) offset,
 				iov_iter_count(from));