From: Dave Chinner <david@fromorbit.com>
To: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Subject: [PATCH 12/16] iomap: zero-around in iomap_page_mkwrite
Date: Wed, 7 Nov 2018 17:31:23 +1100 [thread overview]
Message-ID: <20181107063127.3902-13-david@fromorbit.com> (raw)
In-Reply-To: <20181107063127.3902-1-david@fromorbit.com>
From: Dave Chinner <dchinner@redhat.com>
When we take a write fault over a page in a block size > page size
filesystem, we may have to issue zero-around to initialise all the
pages in the block that mmap is writing to. This is essentially the
same as the zero-around in the buffered write path, with the added
complexity that we have to drop the page lock on the page that
was passed to iomap_page_mkwrite_actor().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/iomap.c | 41 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 40 insertions(+), 1 deletion(-)
diff --git a/fs/iomap.c b/fs/iomap.c
index 41922fc775c4..7aacd48c593e 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1183,7 +1183,46 @@ iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length,
void *data, struct iomap *iomap)
{
struct page *page = data;
- int ret;
+ loff_t ret;
+
+ /*
+ * if we need to zero-around, we have to unlock the page we were given.
+ * No big deal, we just have to repeat the "is this page ours" checks
+ * after relocking it
+ */
+ if (iomap_need_zero_around(iomap)) {
+ loff_t size;
+
+ /*
+ * This only happens for block size > page size, so the file
+ * offset of a page fault should always be page aligned.
+ */
+ WARN_ON(offset_in_page(pos));
+
+ unlock_page(page);
+ ret = iomap_zero_around(inode, pos, length, iomap);
+ lock_page(page);
+ size = i_size_read(inode);
+ if ((page->mapping != inode->i_mapping) ||
+ (page_offset(page) > size)) {
+ /* We overload EFAULT to mean page got truncated */
+ return -EFAULT;
+ }
+
+ if (page_offset(page) != pos) {
+ /* it moved in the file! */
+ return -EFAULT;
+ }
+
+ /* return failure now if zeroing had an error */
+ if (ret)
+ return ret;
+
+ /* trim down the length is we straddle EOF. */
+ if (((page->index + 1) << PAGE_SHIFT) > size)
+ length = offset_in_page(size);
+
+ }
if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
ret = __block_write_begin_int(page, pos, length, NULL, iomap);
--
2.19.1
next prev parent reply other threads:[~2018-11-07 16:01 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 6:31 [RFC PATCH 00/16] xfs: Block size > PAGE_SIZE support Dave Chinner
2018-11-07 6:31 ` [PATCH 01/16] xfs: drop ->writepage completely Dave Chinner
2018-11-09 15:12 ` Christoph Hellwig
2018-11-12 21:08 ` Dave Chinner
2021-02-02 20:51 ` Darrick J. Wong
2018-11-07 6:31 ` [PATCH 02/16] xfs: move writepage context warnings to writepages Dave Chinner
2018-11-07 6:31 ` [PATCH 03/16] xfs: finobt AG reserves don't consider last AG can be a runt Dave Chinner
2018-11-07 16:55 ` Darrick J. Wong
2018-11-09 0:21 ` Dave Chinner
2018-11-07 6:31 ` [PATCH 04/16] xfs: extent shifting doesn't fully invalidate page cache Dave Chinner
2018-11-07 6:31 ` [PATCH 05/16] iomap: sub-block dio needs to zeroout beyond EOF Dave Chinner
2018-11-09 15:15 ` Christoph Hellwig
2018-11-07 6:31 ` [PATCH 06/16] iomap: support block size > page size for direct IO Dave Chinner
2018-11-08 11:28 ` Nikolay Borisov
2018-11-09 15:18 ` Christoph Hellwig
2018-11-11 1:12 ` Dave Chinner
2018-11-07 6:31 ` [PATCH 07/16] iomap: prepare buffered IO paths for block size > page size Dave Chinner
2018-11-09 15:19 ` Christoph Hellwig
2018-11-11 1:15 ` Dave Chinner
2018-11-07 6:31 ` [PATCH 08/16] iomap: mode iomap_zero_range and friends Dave Chinner
2018-11-09 15:19 ` Christoph Hellwig
2018-11-07 6:31 ` [PATCH 09/16] iomap: introduce zero-around functionality Dave Chinner
2018-11-07 6:31 ` [PATCH 10/16] iomap: enable zero-around for iomap_zero_range() Dave Chinner
2018-11-07 6:31 ` [PATCH 11/16] iomap: Don't mark partial pages zeroing uptodate for zero-around Dave Chinner
2018-11-07 6:31 ` Dave Chinner [this message]
2018-11-07 6:31 ` [PATCH 13/16] xfs: add zero-around controls to iomap Dave Chinner
2018-11-07 6:31 ` [PATCH 14/16] xfs: align writepages to large block sizes Dave Chinner
2018-11-09 15:22 ` Christoph Hellwig
2018-11-11 1:20 ` Dave Chinner
2018-11-11 16:32 ` Christoph Hellwig
2018-11-14 14:19 ` Brian Foster
2018-11-14 21:18 ` Dave Chinner
2018-11-15 12:55 ` Brian Foster
2018-11-16 6:19 ` Dave Chinner
2018-11-16 13:29 ` Brian Foster
2018-11-19 1:14 ` Dave Chinner
2018-11-07 6:31 ` [PATCH 15/16] xfs: expose block size in stat Dave Chinner
2018-11-07 6:31 ` [PATCH 16/16] xfs: enable block size larger than page size support Dave Chinner
2018-11-07 17:14 ` [RFC PATCH 00/16] xfs: Block size > PAGE_SIZE support Darrick J. Wong
2018-11-07 22:04 ` Dave Chinner
2018-11-08 1:38 ` Darrick J. Wong
2018-11-08 9:04 ` Dave Chinner
2018-11-08 22:17 ` Darrick J. Wong
2018-11-08 22:22 ` Dave Chinner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181107063127.3902-13-david@fromorbit.com \
--to=david@fromorbit.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).