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From: Christoph Hellwig <hch@lst.de>
To: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
	linux-mm@kvack.org
Subject: [PATCH 15/33] xfs: simplify xfs_aops_discard_page
Date: Wed,  9 May 2018 09:48:12 +0200
Message-ID: <20180509074830.16196-16-hch@lst.de> (raw)
In-Reply-To: <20180509074830.16196-1-hch@lst.de>

Instead of looking at the buffer heads to see if a block is delalloc just
call xfs_bmap_punch_delalloc_range on the whole page - this will leave
any non-delalloc block intact and handle the iteration for us.  As a side
effect one more place stops caring about buffer heads and we can remove the
xfs_check_page_type function entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_aops.c | 85 +++++------------------------------------------
 1 file changed, 9 insertions(+), 76 deletions(-)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 8e4d01e76fc8..313449ac0288 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -711,49 +711,6 @@ xfs_map_at_offset(
 	clear_buffer_unwritten(bh);
 }
 
-/*
- * Test if a given page contains at least one buffer of a given @type.
- * If @check_all_buffers is true, then we walk all the buffers in the page to
- * try to find one of the type passed in. If it is not set, then the caller only
- * needs to check the first buffer on the page for a match.
- */
-STATIC bool
-xfs_check_page_type(
-	struct page		*page,
-	unsigned int		type,
-	bool			check_all_buffers)
-{
-	struct buffer_head	*bh;
-	struct buffer_head	*head;
-
-	if (PageWriteback(page))
-		return false;
-	if (!page->mapping)
-		return false;
-	if (!page_has_buffers(page))
-		return false;
-
-	bh = head = page_buffers(page);
-	do {
-		if (buffer_unwritten(bh)) {
-			if (type == XFS_IO_UNWRITTEN)
-				return true;
-		} else if (buffer_delay(bh)) {
-			if (type == XFS_IO_DELALLOC)
-				return true;
-		} else if (buffer_dirty(bh) && buffer_mapped(bh)) {
-			if (type == XFS_IO_OVERWRITE)
-				return true;
-		}
-
-		/* If we are only checking the first buffer, we are done now. */
-		if (!check_all_buffers)
-			break;
-	} while ((bh = bh->b_this_page) != head);
-
-	return false;
-}
-
 STATIC void
 xfs_vm_invalidatepage(
 	struct page		*page,
@@ -785,9 +742,6 @@ xfs_vm_invalidatepage(
  * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
  * truncation without a transaction as there is no space left for block
  * reservation (typically why we see a ENOSPC in writeback).
- *
- * This is not a performance critical path, so for now just do the punching a
- * buffer head at a time.
  */
 STATIC void
 xfs_aops_discard_page(
@@ -795,47 +749,26 @@ xfs_aops_discard_page(
 {
 	struct inode		*inode = page->mapping->host;
 	struct xfs_inode	*ip = XFS_I(inode);
-	struct buffer_head	*bh, *head;
+	struct xfs_mount	*mp = ip->i_mount;
 	loff_t			offset = page_offset(page);
+	xfs_fileoff_t		start_fsb = XFS_B_TO_FSBT(mp, offset);
+	int			error;
 
-	if (!xfs_check_page_type(page, XFS_IO_DELALLOC, true))
-		goto out_invalidate;
-
-	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+	if (XFS_FORCED_SHUTDOWN(mp))
 		goto out_invalidate;
 
-	xfs_alert(ip->i_mount,
+	xfs_alert(mp,
 		"page discard on page "PTR_FMT", inode 0x%llx, offset %llu.",
 			page, ip->i_ino, offset);
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
-	bh = head = page_buffers(page);
-	do {
-		int		error;
-		xfs_fileoff_t	start_fsb;
-
-		if (!buffer_delay(bh))
-			goto next_buffer;
-
-		start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
-		error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
-		if (error) {
-			/* something screwed, just bail */
-			if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
-				xfs_alert(ip->i_mount,
-			"page discard unable to remove delalloc mapping.");
-			}
-			break;
-		}
-next_buffer:
-		offset += i_blocksize(inode);
-
-	} while ((bh = bh->b_this_page) != head);
-
+	error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
+			PAGE_SIZE / i_blocksize(inode));
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	if (error && !XFS_FORCED_SHUTDOWN(mp))
+		xfs_alert(mp, "page discard unable to remove delalloc mapping.");
 out_invalidate:
 	xfs_vm_invalidatepage(page, 0, PAGE_SIZE);
-	return;
 }
 
 static int
-- 
2.17.0

  parent reply index

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-09  7:47 stop using buffer heads in xfs and iomap Christoph Hellwig
2018-05-09  7:47 ` [PATCH 01/33] block: add a lower-level bio_add_page interface Christoph Hellwig
2018-05-09 15:12   ` Matthew Wilcox
2018-05-10  6:40     ` Christoph Hellwig
2018-05-10 21:49       ` Andreas Dilger
2018-05-11  6:29         ` Christoph Hellwig
2018-05-15 16:47           ` Jens Axboe
2018-05-10  8:52   ` Ming Lei
2018-05-11  6:24     ` Christoph Hellwig
2018-05-16  5:06   ` Ritesh Harjani
2018-05-16 18:05     ` Christoph Hellwig
2018-05-17  4:18       ` Ritesh Harjani
2018-05-09  7:47 ` [PATCH 02/33] fs: factor out a __generic_write_end helper Christoph Hellwig
2018-05-09 15:15   ` Matthew Wilcox
2018-05-10  6:40     ` Christoph Hellwig
2018-05-09  7:48 ` [PATCH 03/33] fs: move page_cache_seek_hole_data to iomap.c Christoph Hellwig
2018-05-09  7:48 ` [PATCH 04/33] fs: remove the buffer_unwritten check in page_seek_hole_data Christoph Hellwig
2018-05-17 11:33   ` Andreas Grünbacher
2018-05-09  7:48 ` [PATCH 05/33] fs: use ->is_partially_uptodate in page_cache_seek_hole_data Christoph Hellwig
2018-05-09  7:48 ` [PATCH 06/33] mm: give the 'ret' variable a better name __do_page_cache_readahead Christoph Hellwig
2018-05-09 15:45   ` Matthew Wilcox
2018-05-10  6:41     ` Christoph Hellwig
2018-05-09  7:48 ` [PATCH 07/33] mm: split ->readpages calls to avoid non-contiguous pages lists Christoph Hellwig
2018-05-09 15:46   ` Matthew Wilcox
2018-05-09  7:48 ` [PATCH 08/33] iomap: use __bio_add_page in iomap_dio_zero Christoph Hellwig
2018-05-09  7:48 ` [PATCH 09/33] iomap: add a iomap_sector helper Christoph Hellwig
2018-05-09  7:48 ` [PATCH 10/33] iomap: add an iomap-based bmap implementation Christoph Hellwig
2018-05-09 16:46   ` Darrick J. Wong
2018-05-10  6:42     ` Christoph Hellwig
2018-05-10 15:08       ` Darrick J. Wong
2018-05-11  6:25         ` Christoph Hellwig
2018-05-12  1:56           ` Darrick J. Wong
2018-05-09  7:48 ` [PATCH 11/33] iomap: add an iomap-based readpage and readpages implementation Christoph Hellwig
2018-05-10  1:17   ` Dave Chinner
2018-05-10  6:44     ` Christoph Hellwig
2018-05-09  7:48 ` [PATCH 12/33] xfs: use iomap_bmap Christoph Hellwig
2018-05-09  7:48 ` [PATCH 13/33] xfs: use iomap for blocksize == PAGE_SIZE readpage and readpages Christoph Hellwig
2018-05-09  7:48 ` [PATCH 14/33] xfs: simplify xfs_bmap_punch_delalloc_range Christoph Hellwig
2018-05-09  7:48 ` Christoph Hellwig [this message]
2018-05-09  7:48 ` [PATCH 16/33] xfs: move locking into xfs_bmap_punch_delalloc_range Christoph Hellwig
2018-05-09  7:48 ` [PATCH 17/33] xfs: make xfs_writepage_map extent map centric Christoph Hellwig
2018-05-09  7:48 ` [PATCH 18/33] xfs: remove the now unused XFS_BMAPI_IGSTATE flag Christoph Hellwig
2018-05-09  7:48 ` [PATCH 19/33] xfs: remove xfs_reflink_find_cow_mapping Christoph Hellwig
2018-05-09  7:48 ` [PATCH 20/33] xfs: remove xfs_reflink_trim_irec_to_next_cow Christoph Hellwig
2018-05-09  7:48 ` [PATCH 21/33] xfs: simplify xfs_map_blocks by using xfs_iext_lookup_extent directly Christoph Hellwig
2018-05-09  7:48 ` [PATCH 22/33] xfs: don't clear imap_valid for a non-uptodate buffers Christoph Hellwig
2018-05-09  7:48 ` [PATCH 23/33] xfs: remove the imap_valid flag Christoph Hellwig
2018-05-09  7:48 ` [PATCH 24/33] xfs: don't look at buffer heads in xfs_add_to_ioend Christoph Hellwig
2018-05-09  7:48 ` [PATCH 25/33] xfs: move all writeback buffer_head manipulation into xfs_map_at_offset Christoph Hellwig
2018-05-09  7:48 ` [PATCH 26/33] xfs: allow writeback on pages without buffer heads Christoph Hellwig
2018-05-09  7:48 ` [PATCH 27/33] xfs: remove xfs_start_page_writeback Christoph Hellwig
2018-05-09  7:48 ` [PATCH 28/33] xfs: refactor the tail of xfs_writepage_map Christoph Hellwig
2018-05-09  7:48 ` [PATCH 29/33] xfs: do not set the page uptodate in xfs_writepage_map Christoph Hellwig
2018-05-09  7:48 ` [PATCH 30/33] iomap: add initial support for writes without buffer heads Christoph Hellwig
2018-05-09  7:48 ` [PATCH 31/33] iomap: add support for sub-pagesize buffered I/O " Christoph Hellwig
2018-05-14 16:00   ` Goldwyn Rodrigues
2018-05-15  7:26     ` Christoph Hellwig
2018-05-15 13:47       ` Goldwyn Rodrigues
2018-05-16  5:46         ` Dave Chinner
2018-05-09  7:48 ` [PATCH 32/33] xfs: add support for sub-pagesize writeback without buffer_heads Christoph Hellwig
2018-05-09  7:48 ` [PATCH 33/33] fs: remove __block_write_begin and iomap_to_bh Christoph Hellwig
2018-05-10 15:13 ` stop using buffer heads in xfs and iomap Darrick J. Wong
2018-05-11  6:22   ` Christoph Hellwig
2018-05-11  6:39     ` Darrick J. Wong

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