From: Andreas Gruenbacher <agruenba@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>,
cluster-devel@redhat.com, linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
Matthew Wilcox <willy@infradead.org>
Subject: [RFC 5/9] iov_iter: Add iov_iter_fault_in_writeable()
Date: Mon, 31 May 2021 19:01:19 +0200 [thread overview]
Message-ID: <20210531170123.243771-6-agruenba@redhat.com> (raw)
In-Reply-To: <20210531170123.243771-1-agruenba@redhat.com>
Add the equivalent of iov_iter_fault_in_readable(), but for pages that
will be written to.
While at it, fix an indentation error in iov_iter_fault_in_readable().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
include/linux/uio.h | 1 +
lib/iov_iter.c | 20 +++++++++++++++++++-
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/include/linux/uio.h b/include/linux/uio.h
index d3ec87706d75..6811eb6ac6e3 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -124,6 +124,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
void iov_iter_advance(struct iov_iter *i, size_t bytes);
void iov_iter_revert(struct iov_iter *i, size_t bytes);
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
+int iov_iter_fault_in_writeable(struct iov_iter *i, size_t bytes);
size_t iov_iter_single_seg_count(const struct iov_iter *i);
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index c701b7a187f2..317c94eac907 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -480,13 +480,31 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
iterate_iovec(i, bytes, v, iov, skip, ({
err = fault_in_pages_readable(v.iov_base, v.iov_len);
if (unlikely(err))
- return err;
+ return err;
0;}))
}
return 0;
}
EXPORT_SYMBOL(iov_iter_fault_in_readable);
+int iov_iter_fault_in_writeable(struct iov_iter *i, size_t bytes)
+{
+ size_t skip = i->iov_offset;
+ const struct iovec *iov;
+ int err;
+ struct iovec v;
+
+ if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
+ iterate_iovec(i, bytes, v, iov, skip, ({
+ err = fault_in_pages_writeable(v.iov_base, v.iov_len);
+ if (unlikely(err))
+ return err;
+ 0;}))
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iov_iter_fault_in_writeable);
+
void iov_iter_init(struct iov_iter *i, unsigned int direction,
const struct iovec *iov, unsigned long nr_segs,
size_t count)
--
2.26.3
next prev parent reply other threads:[~2021-05-31 17:09 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-31 17:01 [RFC 0/9] gfs2: handle page faults during read and write Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 1/9] gfs2: Clean up the error handling in gfs2_page_mkwrite Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 2/9] gfs2: Add wrapper for iomap_file_buffered_write Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 3/9] gfs2: Add gfs2_holder_is_compatible helper Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 4/9] gfs2: Fix mmap + page fault deadlocks (part 1) Andreas Gruenbacher
2021-06-01 6:00 ` Linus Torvalds
2021-06-02 11:16 ` Andreas Gruenbacher
2021-06-11 16:25 ` Al Viro
2021-06-12 21:05 ` Al Viro
2021-06-12 21:35 ` Al Viro
2021-06-13 8:44 ` [Cluster-devel] " Steven Whitehouse
2021-05-31 17:01 ` Andreas Gruenbacher [this message]
2021-05-31 17:12 ` [RFC 5/9] iov_iter: Add iov_iter_fault_in_writeable() Al Viro
2021-06-12 21:12 ` Al Viro
2021-06-12 21:33 ` Linus Torvalds
2021-06-12 21:47 ` Al Viro
2021-06-12 23:17 ` Linus Torvalds
2021-06-12 23:38 ` Al Viro
2021-05-31 17:01 ` [RFC 6/9] gfs2: Add wrappers for accessing journal_info Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 7/9] gfs2: Encode glock holding and retry flags in journal_info Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 8/9] gfs2: Add LM_FLAG_OUTER glock holder flag Andreas Gruenbacher
2021-05-31 17:01 ` [RFC 9/9] gfs2: Fix mmap + page fault deadlocks (part 2) Andreas Gruenbacher
2021-06-01 5:47 ` Linus Torvalds
[not found] ` <CAHk-=wgX=fZ+y=SxBsod8CvZmZ0-X7vZ6dV6EgLPkpBXbt=nQQ@mail.gmail.com>
2021-05-31 20:35 ` [RFC 0/9] gfs2: handle page faults during read and write Andreas Gruenbacher
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