From: Dave Kleikamp <dave.kleikamp@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
"Maxim V. Patlasov" <mpatlasov@parallels.com>,
Zach Brown <zab@zabbo.net>,
Dave Kleikamp <dave.kleikamp@oracle.com>
Subject: [PATCH V8 03/33] iov_iter: add copy_to_user support
Date: Thu, 25 Jul 2013 12:50:29 -0500 [thread overview]
Message-ID: <1374774659-13121-4-git-send-email-dave.kleikamp@oracle.com> (raw)
In-Reply-To: <1374774659-13121-1-git-send-email-dave.kleikamp@oracle.com>
From: Zach Brown <zab@zabbo.net>
This adds iov_iter wrappers around copy_to_user() to match the existing
wrappers around copy_from_user().
This will be used by the generic file system buffered read path.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
fs/iov-iter.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 4 +++
2 files changed, 84 insertions(+)
diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index 563a6ba..0b2407e 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -6,6 +6,86 @@
#include <linux/highmem.h>
#include <linux/pagemap.h>
+static size_t __iovec_copy_to_user(char *vaddr, const struct iovec *iov,
+ size_t base, size_t bytes, int atomic)
+{
+ size_t copied = 0, left = 0;
+
+ while (bytes) {
+ char __user *buf = iov->iov_base + base;
+ int copy = min(bytes, iov->iov_len - base);
+
+ base = 0;
+ if (atomic)
+ left = __copy_to_user_inatomic(buf, vaddr, copy);
+ else
+ left = copy_to_user(buf, vaddr, copy);
+ copied += copy;
+ bytes -= copy;
+ vaddr += copy;
+ iov++;
+
+ if (unlikely(left))
+ break;
+ }
+ return copied - left;
+}
+
+/*
+ * Copy as much as we can into the page and return the number of bytes which
+ * were sucessfully copied. If a fault is encountered then return the number of
+ * bytes which were copied.
+ */
+size_t iov_iter_copy_to_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr;
+ size_t copied;
+
+ BUG_ON(!in_atomic());
+ kaddr = kmap_atomic(page);
+ if (likely(i->nr_segs == 1)) {
+ int left;
+ char __user *buf = i->iov->iov_base + i->iov_offset;
+ left = __copy_to_user_inatomic(buf, kaddr + offset, bytes);
+ copied = bytes - left;
+ } else {
+ copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+ i->iov_offset, bytes, 1);
+ }
+ kunmap_atomic(kaddr);
+
+ return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_to_user_atomic);
+
+/*
+ * This has the same sideeffects and return value as
+ * iov_iter_copy_to_user_atomic().
+ * The difference is that it attempts to resolve faults.
+ * Page must not be locked.
+ */
+size_t iov_iter_copy_to_user(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+ char *kaddr;
+ size_t copied;
+
+ kaddr = kmap(page);
+ if (likely(i->nr_segs == 1)) {
+ int left;
+ char __user *buf = i->iov->iov_base + i->iov_offset;
+ left = copy_to_user(buf, kaddr + offset, bytes);
+ copied = bytes - left;
+ } else {
+ copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+ i->iov_offset, bytes, 0);
+ }
+ kunmap(page);
+ return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_to_user);
+
static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
size_t base, size_t bytes, int atomic)
{
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9818747..80f71df 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -296,6 +296,10 @@ struct iov_iter {
size_t count;
};
+size_t iov_iter_copy_to_user_atomic(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes);
+size_t iov_iter_copy_to_user(struct page *page,
+ struct iov_iter *i, unsigned long offset, size_t bytes);
size_t iov_iter_copy_from_user_atomic(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes);
size_t iov_iter_copy_from_user(struct page *page,
--
1.8.3.4
next prev parent reply other threads:[~2013-07-25 17:50 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-25 17:50 [PATCH V8 00/33] loop: Issue O_DIRECT aio using bio_vec Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 01/33] iov_iter: move into its own file Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 02/33] iov_iter: iov_iter_copy_from_user() should use non-atomic copy Dave Kleikamp
2013-07-25 17:50 ` Dave Kleikamp [this message]
2013-07-25 17:50 ` [PATCH V8 04/33] iov_iter: add __iovec_copy_to_user() Dave Kleikamp
[not found] ` <1374774659-13121-1-git-send-email-dave.kleikamp-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2013-07-25 17:50 ` [PATCH V8 05/33] fuse: convert fuse to use iov_iter_copy_[to|from]_user Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 06/33] iov_iter: hide iovec details behind ops function pointers Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 07/33] iov_iter: ii_iovec_copy_to_user should pre-fault user pages Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 08/33] iov_iter: add bvec support Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 09/33] iov_iter: add a shorten call Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 10/33] iov_iter: let callers extract iovecs and bio_vecs Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 11/33] dio: Convert direct_IO to use iov_iter Dave Kleikamp
2013-08-23 15:48 ` Geert Uytterhoeven
2013-07-25 17:50 ` [PATCH V8 12/33] dio: add bio_vec support to __blockdev_direct_IO() Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 13/33] fs: pull iov_iter use higher up the stack Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 14/33] aio: add aio_kernel_() interface Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 15/33] aio: add aio support for iov_iter arguments Dave Kleikamp
2013-08-21 13:55 ` Benjamin LaHaise
2013-08-30 20:05 ` Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 16/33] bio: add bvec_length(), like iov_length() Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 17/33] loop: use aio to perform io on the underlying file Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 18/33] fs: create file_readable() and file_writable() functions Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 19/33] fs: use read_iter and write_iter rather than aio_read and aio_write Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 20/33] fs: add read_iter and write_iter to several file systems Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 21/33] ocfs2: add support for read_iter and write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 22/33] ext4: " Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 23/33] nfs: add support for read_iter, write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 24/33] nfs: simplify swap Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 25/33] btrfs: add support for read_iter and write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 26/33] block_dev: add support for read_iter, write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 27/33] xfs: add support for read_iter and write_iter Dave Kleikamp
2013-07-26 11:51 ` Dave Chinner
2013-07-25 17:50 ` [PATCH V8 28/33] gfs2: Convert aio_read/write ops to read/write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 29/33] udf: convert file ops from aio_read/write " Dave Kleikamp
2013-07-25 21:34 ` Jan Kara
2013-07-25 17:50 ` [PATCH V8 30/33] afs: add support for read_iter and write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 31/33] ecrpytfs: Convert aio_read/write ops to read/write_iter Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 32/33] ubifs: convert file ops from aio_read/write " Dave Kleikamp
2013-07-25 17:50 ` [PATCH V8 33/33] tmpfs: add support for read_iter and write_iter Dave Kleikamp
2013-07-30 21:28 ` [PATCH V8 00/33] loop: Issue O_DIRECT aio using bio_vec Andrew Morton
2013-07-31 0:43 ` Dave Chinner
2013-07-31 6:40 ` Sedat Dilek
2013-07-31 8:41 ` Sedat Dilek
2013-07-31 11:22 ` Sedat Dilek
2013-07-31 9:51 ` Maxim Patlasov
2013-08-01 8:58 ` Christoph Hellwig
2013-08-01 13:04 ` Dave Kleikamp
2013-08-02 10:48 ` Christoph Hellwig
2013-08-20 13:00 ` Christoph Hellwig
2013-08-20 19:13 ` Dave Kleikamp
2013-08-21 0:14 ` Stephen Rothwell
2013-08-21 5:35 ` Sedat Dilek
2013-08-20 22:46 ` Andrew Morton
2013-08-21 13:02 ` Benjamin LaHaise
2013-08-21 16:30 ` Dave Kleikamp
2013-08-21 16:39 ` Benjamin LaHaise
2013-08-21 17:12 ` Dave Kleikamp
2013-08-21 19:30 ` Andrew Morton
2013-08-21 20:24 ` Benjamin LaHaise
2013-10-14 15:07 ` Christoph Hellwig
2013-10-14 21:29 ` Benjamin LaHaise
2013-10-15 16:55 ` Christoph Hellwig
2013-10-15 17:14 ` Benjamin LaHaise
2013-10-15 17:18 ` Christoph Hellwig
2013-10-15 17:53 ` Dave Kleikamp
2014-12-31 20:38 ` Sedat Dilek
2014-12-31 21:52 ` Dave Kleikamp
2014-12-31 22:35 ` Sedat Dilek
2015-01-01 0:52 ` Ming Lei
2015-01-05 19:24 ` Maxim Patlasov
2015-01-06 13:18 ` Ming Lei
2015-01-10 16:51 ` Ming Lei
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