From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Christoph Hellwig To: linux-xfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 20/34] xfs: simplify xfs_aops_discard_page Date: Wed, 23 May 2018 16:43:43 +0200 Message-Id: <20180523144357.18985-21-hch@lst.de> In-Reply-To: <20180523144357.18985-1-hch@lst.de> References: <20180523144357.18985-1-hch@lst.de> Sender: owner-linux-mm@kvack.org List-ID: 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 --- 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 c631c457b444..f2333e351e07 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