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From: David Howells <dhowells@redhat.com>
To: Pavel Begunkov <asml.silence@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	Jens Axboe <axboe@kernel.dk>,
	Alexander Viro <viro@zeniv.linux.org.uk>
Cc: dhowells@redhat.com,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 15/29] iov_iter: Split copy_from_user_atomic()
Date: Sat, 21 Nov 2020 14:15:19 +0000	[thread overview]
Message-ID: <160596811958.154728.14803339635754597304.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <160596800145.154728.7192318545120181269.stgit@warthog.procyon.org.uk>

Split copy_from_user_atomic() by type.

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

 lib/iov_iter.c |   53 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9a167f53ecff..a626d41fef72 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1195,7 +1195,7 @@ static size_t discard_zero(size_t bytes, struct iov_iter *i)
 	return bytes;
 }
 
-static size_t xxx_copy_from_user_atomic(struct page *page,
+static size_t iovec_copy_from_user_atomic(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes)
 {
 	char *kaddr = kmap_atomic(page), *p = kaddr + offset;
@@ -1203,21 +1203,48 @@ static size_t xxx_copy_from_user_atomic(struct page *page,
 		kunmap_atomic(kaddr);
 		return 0;
 	}
-	if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
+	iterate_over_iovec(i, bytes, v,
+		copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+	kunmap_atomic(kaddr);
+	return bytes;
+}
+
+static size_t bvec_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+	if (unlikely(!page_copy_sane(page, offset, bytes))) {
 		kunmap_atomic(kaddr);
-		WARN_ON(1);
 		return 0;
 	}
-	iterate_all_kinds(i, bytes, v,
-		copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+	iterate_over_bvec(i, bytes, v,
 		memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
-				 v.bv_offset, v.bv_len),
-		memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
-	)
+				 v.bv_offset, v.bv_len));
 	kunmap_atomic(kaddr);
 	return bytes;
 }
 
+static size_t kvec_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+	if (unlikely(!page_copy_sane(page, offset, bytes))) {
+		kunmap_atomic(kaddr);
+		return 0;
+	}
+	iterate_over_kvec(i, bytes, v,
+		memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+	kunmap_atomic(kaddr);
+	return bytes;
+}
+
+static size_t no_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	WARN_ON(1);
+	return 0;
+}
+
 static inline void pipe_truncate(struct iov_iter *i)
 {
 	struct pipe_inode_info *pipe = i->pipe;
@@ -2046,7 +2073,7 @@ static int xxx_for_each_range(struct iov_iter *i, size_t bytes,
 
 static const struct iov_iter_ops iovec_iter_ops = {
 	.type				= ITER_IOVEC,
-	.copy_from_user_atomic		= xxx_copy_from_user_atomic,
+	.copy_from_user_atomic		= iovec_copy_from_user_atomic,
 	.advance			= xxx_advance,
 	.revert				= xxx_revert,
 	.fault_in_readable		= iovec_fault_in_readable,
@@ -2080,7 +2107,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
 
 static const struct iov_iter_ops kvec_iter_ops = {
 	.type				= ITER_KVEC,
-	.copy_from_user_atomic		= xxx_copy_from_user_atomic,
+	.copy_from_user_atomic		= kvec_copy_from_user_atomic,
 	.advance			= xxx_advance,
 	.revert				= xxx_revert,
 	.fault_in_readable		= no_fault_in_readable,
@@ -2114,7 +2141,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
 
 static const struct iov_iter_ops bvec_iter_ops = {
 	.type				= ITER_BVEC,
-	.copy_from_user_atomic		= xxx_copy_from_user_atomic,
+	.copy_from_user_atomic		= bvec_copy_from_user_atomic,
 	.advance			= xxx_advance,
 	.revert				= xxx_revert,
 	.fault_in_readable		= no_fault_in_readable,
@@ -2148,7 +2175,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
 
 static const struct iov_iter_ops pipe_iter_ops = {
 	.type				= ITER_PIPE,
-	.copy_from_user_atomic		= xxx_copy_from_user_atomic,
+	.copy_from_user_atomic		= no_copy_from_user_atomic,
 	.advance			= xxx_advance,
 	.revert				= xxx_revert,
 	.fault_in_readable		= no_fault_in_readable,
@@ -2182,7 +2209,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
 
 static const struct iov_iter_ops discard_iter_ops = {
 	.type				= ITER_DISCARD,
-	.copy_from_user_atomic		= xxx_copy_from_user_atomic,
+	.copy_from_user_atomic		= no_copy_from_user_atomic,
 	.advance			= xxx_advance,
 	.revert				= xxx_revert,
 	.fault_in_readable		= no_fault_in_readable,



  parent reply	other threads:[~2020-11-21 14:15 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-21 14:13 [PATCH 00/29] RFC: iov_iter: Switch to using an ops table David Howells
2020-11-21 14:13 ` [PATCH 01/29] iov_iter: Switch to using a table of operations David Howells
2020-11-21 14:31   ` Pavel Begunkov
2020-11-23 23:21     ` Pavel Begunkov
2020-11-21 18:21   ` Linus Torvalds
2020-12-11  1:30     ` Al Viro
2020-11-22 13:33   ` David Howells
2020-11-22 13:58     ` David Laight
2020-11-22 19:22     ` Linus Torvalds
2020-11-22 22:34       ` David Laight
2020-11-22 22:46   ` David Laight
2020-11-23  8:05   ` Christoph Hellwig
2020-11-23 10:31   ` David Howells
2020-11-23 23:42     ` Pavel Begunkov
2020-11-24 12:50     ` David Howells
2020-11-24 15:30       ` Jens Axboe
2020-11-27 17:14       ` David Howells
2020-11-23 11:14   ` David Howells
2020-12-03  6:45   ` [iov_iter] 9bd0e337c6: will-it-scale.per_process_ops -4.8% regression kernel test robot
2020-12-03  6:45     ` kernel test robot
2020-12-03 17:47     ` Linus Torvalds
2020-12-03 17:47       ` Linus Torvalds
2020-12-03 17:50       ` Jens Axboe
2020-12-03 17:50         ` Jens Axboe
2020-12-04 11:50     ` David Howells
2020-12-04 11:50       ` David Howells
2020-12-04 11:51     ` David Howells
2020-12-04 11:51       ` David Howells
2020-12-07 13:10       ` Oliver Sang
2020-12-07 13:10         ` Oliver Sang
2020-12-07 13:20       ` David Howells
2020-12-07 13:20         ` David Howells
2020-11-21 14:13 ` [PATCH 02/29] iov_iter: Split copy_page_to_iter() David Howells
2020-11-21 14:13 ` [PATCH 03/29] iov_iter: Split iov_iter_fault_in_readable David Howells
2020-11-21 14:13 ` [PATCH 04/29] iov_iter: Split the iterate_and_advance() macro David Howells
2020-11-21 14:14 ` [PATCH 05/29] iov_iter: Split copy_to_iter() David Howells
2020-11-21 14:14 ` [PATCH 06/29] iov_iter: Split copy_mc_to_iter() David Howells
2020-11-21 14:14 ` [PATCH 07/29] iov_iter: Split copy_from_iter() David Howells
2020-11-21 14:14 ` [PATCH 08/29] iov_iter: Split the iterate_all_kinds() macro David Howells
2020-11-21 14:14 ` [PATCH 09/29] iov_iter: Split copy_from_iter_full() David Howells
2020-11-21 14:14 ` [PATCH 10/29] iov_iter: Split copy_from_iter_nocache() David Howells
2020-11-21 14:14 ` [PATCH 11/29] iov_iter: Split copy_from_iter_flushcache() David Howells
2020-11-21 14:14 ` [PATCH 12/29] iov_iter: Split copy_from_iter_full_nocache() David Howells
2020-11-21 14:15 ` [PATCH 13/29] iov_iter: Split copy_page_from_iter() David Howells
2020-11-21 14:15 ` [PATCH 14/29] iov_iter: Split iov_iter_zero() David Howells
2020-11-21 14:15 ` David Howells [this message]
2020-11-21 14:15 ` [PATCH 16/29] iov_iter: Split iov_iter_advance() David Howells
2020-11-21 14:15 ` [PATCH 17/29] iov_iter: Split iov_iter_revert() David Howells
2020-11-21 14:15 ` [PATCH 18/29] iov_iter: Split iov_iter_single_seg_count() David Howells
2020-11-21 14:15 ` [PATCH 19/29] iov_iter: Split iov_iter_alignment() David Howells
2020-11-21 14:15 ` [PATCH 20/29] iov_iter: Split iov_iter_gap_alignment() David Howells
2020-11-21 14:16 ` [PATCH 21/29] iov_iter: Split iov_iter_get_pages() David Howells
2020-11-21 14:16 ` [PATCH 22/29] iov_iter: Split iov_iter_get_pages_alloc() David Howells
2020-11-21 14:16 ` [PATCH 23/29] iov_iter: Split csum_and_copy_from_iter() David Howells
2020-11-21 14:16 ` [PATCH 24/29] iov_iter: Split csum_and_copy_from_iter_full() David Howells
2020-11-21 14:16 ` [PATCH 25/29] iov_iter: Split csum_and_copy_to_iter() David Howells
2020-11-21 14:16 ` [PATCH 26/29] iov_iter: Split iov_iter_npages() David Howells
2020-11-21 14:16 ` [PATCH 27/29] iov_iter: Split dup_iter() David Howells
2020-11-21 14:17 ` [PATCH 28/29] iov_iter: Split iov_iter_for_each_range() David Howells
2020-11-21 14:17 ` [PATCH 29/29] iov_iter: Remove iterate_all_kinds() and iterate_and_advance() David Howells
2020-11-21 14:34 ` [PATCH 00/29] RFC: iov_iter: Switch to using an ops table Pavel Begunkov
2020-11-21 18:23 ` Linus Torvalds
2020-12-11  3:24 ` Matthew Wilcox

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