From: Christoph Hellwig <hch@lst.de>
To: Goldwyn Rodrigues <rgoldwyn@suse.com>,
linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 06/19] iomap: use write_begin to read pages to unshare
Date: Mon, 9 Sep 2019 20:27:09 +0200 [thread overview]
Message-ID: <20190909182722.16783-7-hch@lst.de> (raw)
In-Reply-To: <20190909182722.16783-1-hch@lst.de>
Use the existing iomap write_begin code to read the pages unshared
by iomap_file_unshare. That avoids the extra ->readpage call and
extent tree lookup currently done by read_mapping_page.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/iomap/buffered-io.c | 49 ++++++++++++++----------------------------
1 file changed, 16 insertions(+), 33 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index fe099faf540f..a421977a9496 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -533,6 +533,10 @@ iomap_migrate_page(struct address_space *mapping, struct page *newpage,
EXPORT_SYMBOL_GPL(iomap_migrate_page);
#endif /* CONFIG_MIGRATION */
+enum {
+ IOMAP_WRITE_F_UNSHARE = (1 << 0),
+};
+
static void
iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
{
@@ -562,7 +566,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff,
}
static int
-__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
+__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags,
struct page *page, struct iomap *iomap)
{
struct iomap_page *iop = iomap_page_create(inode, page);
@@ -581,11 +585,14 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
if (plen == 0)
break;
- if ((from <= poff || from >= poff + plen) &&
+ if (!(flags & IOMAP_WRITE_F_UNSHARE) &&
+ (from <= poff || from >= poff + plen) &&
(to <= poff || to >= poff + plen))
continue;
if (iomap_block_needs_zeroing(inode, iomap, block_start)) {
+ if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE))
+ return -EIO;
zero_user_segments(page, poff, from, to, poff + plen);
iomap_set_range_uptodate(page, poff, plen);
continue;
@@ -631,7 +638,8 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
status = __block_write_begin_int(page, pos, len, NULL, iomap);
else
- status = __iomap_write_begin(inode, pos, len, page, iomap);
+ status = __iomap_write_begin(inode, pos, len, flags, page,
+ iomap);
if (unlikely(status))
goto out_unlock;
@@ -854,22 +862,6 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter,
}
EXPORT_SYMBOL_GPL(iomap_file_buffered_write);
-static struct page *
-__iomap_read_page(struct inode *inode, loff_t offset)
-{
- struct address_space *mapping = inode->i_mapping;
- struct page *page;
-
- page = read_mapping_page(mapping, offset >> PAGE_SHIFT, NULL);
- if (IS_ERR(page))
- return page;
- if (!PageUptodate(page)) {
- put_page(page);
- return ERR_PTR(-EIO);
- }
- return page;
-}
-
static loff_t
iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -885,24 +877,15 @@ iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
return length;
do {
- struct page *page, *rpage;
- unsigned long offset; /* Offset into pagecache page */
- unsigned long bytes; /* Bytes to write to page */
-
- offset = offset_in_page(pos);
- bytes = min_t(loff_t, PAGE_SIZE - offset, length);
-
- rpage = __iomap_read_page(inode, pos);
- if (IS_ERR(rpage))
- return PTR_ERR(rpage);
+ unsigned long offset = offset_in_page(pos);
+ unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length);
+ struct page *page;
- status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap);
- put_page(rpage);
+ status = iomap_write_begin(inode, pos, bytes,
+ IOMAP_WRITE_F_UNSHARE, &page, iomap);
if (unlikely(status))
return status;
- WARN_ON_ONCE(!PageUptodate(page));
-
status = iomap_write_end(inode, pos, bytes, bytes, page, iomap);
if (unlikely(status <= 0)) {
if (WARN_ON_ONCE(status == 0))
--
2.20.1
next prev parent reply other threads:[~2019-09-09 18:27 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 18:27 iomap and xfs COW cleanups Christoph Hellwig
2019-09-09 18:27 ` [PATCH 01/19] iomap: better document the IOMAP_F_* flags Christoph Hellwig
2019-09-14 0:42 ` Allison Collins
2019-09-16 18:08 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 02/19] iomap: remove the unused iomap argument to __iomap_write_end Christoph Hellwig
2019-09-14 0:42 ` Allison Collins
2019-09-16 18:10 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 03/19] iomap: always use AOP_FLAG_NOFS in iomap_write_begin Christoph Hellwig
2019-09-16 18:11 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 04/19] iomap: ignore non-shared or non-data blocks in xfs_file_dirty Christoph Hellwig
2019-09-16 18:12 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 05/19] iomap: move the zeroing case out of iomap_read_page_sync Christoph Hellwig
2019-09-16 18:17 ` Darrick J. Wong
2019-09-09 18:27 ` Christoph Hellwig [this message]
2019-09-16 18:34 ` [PATCH 06/19] iomap: use write_begin to read pages to unshare Darrick J. Wong
2019-09-30 11:07 ` Christoph Hellwig
2019-10-08 15:12 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 07/19] iomap: use a srcmap for a read-modify-write I/O Christoph Hellwig
2019-09-10 12:48 ` Goldwyn Rodrigues
2019-09-10 14:39 ` hch
2019-09-16 17:57 ` Darrick J. Wong
2019-09-16 18:42 ` Darrick J. Wong
2019-09-18 18:15 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 08/19] xfs: also call xfs_file_iomap_end_delalloc for zeroing operations Christoph Hellwig
2019-09-18 17:09 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 09/19] xfs: remove xfs_reflink_dirty_extents Christoph Hellwig
2019-09-18 17:17 ` Darrick J. Wong
2019-09-18 17:25 ` Christoph Hellwig
2019-09-18 17:31 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 10/19] xfs: pass two imaps to xfs_reflink_allocate_cow Christoph Hellwig
2019-09-18 17:26 ` Darrick J. Wong
2019-09-30 11:10 ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 11/19] xfs: refactor xfs_file_iomap_begin_delay Christoph Hellwig
2019-09-18 17:30 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 12/19] xfs: fill out the srcmap in iomap_begin Christoph Hellwig
2019-09-18 17:52 ` Darrick J. Wong
2019-10-01 6:26 ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 13/19] xfs: factor out a helper to calculate the end_fsb Christoph Hellwig
2019-09-14 0:42 ` Allison Collins
2019-09-18 17:55 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 14/19] xfs: split out a new set of read-only iomap ops Christoph Hellwig
2019-09-18 17:56 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 15/19] xfs: move xfs_file_iomap_begin_delay around Christoph Hellwig
2019-09-18 17:59 ` Darrick J. Wong
2019-09-30 11:14 ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 16/19] xfs: split the iomap ops for buffered vs direct writes Christoph Hellwig
2019-09-18 18:00 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 17/19] xfs: rename the whichfork variable in xfs_buffered_write_iomap_begin Christoph Hellwig
2019-09-14 0:42 ` Allison Collins
2019-09-18 18:00 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 18/19] xfs: cleanup xfs_iomap_write_unwritten Christoph Hellwig
2019-09-18 18:06 ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 19/19] xfs: improve the IOMAP_NOWAIT check for COW inodes Christoph Hellwig
2019-09-18 18:09 ` Darrick J. Wong
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