From 075bdbdbe9f21d68950ba5b187f80a4a23105365 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 9 Oct 2014 21:18:55 +0100 Subject: [PATCH] Btrfs: correctly flush compressed data before/after direct IO For compressed writes, after doing the first filemap_fdatawrite_range() we don't get the pages tagged for writeback immediately. Instead we create a workqueue task, which is run by other kthread, and keep the pages locked. That other kthread compresses data, creates the respective ordered extent/s, tags the pages for writeback and unlocks them. Therefore we need a second call to filemap_fdatawrite_range() if we have compressed writes, as this second call will wait for the pages to become unlocked, then see they became tagged for writeback and finally wait for the writeback to finish. Signed-off-by: Filipe Manana Signed-off-by: Chris Mason --- fs/btrfs/file.c | 12 +++++++++++- fs/btrfs/inode.c | 16 +++++++++++++--- 2 files changed, 24 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index a18ceabd99a8..f5a868ab60f3 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1692,8 +1692,18 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb, err = written_buffered; goto out; } + /* + * Ensure all data is persisted. We want the next direct IO read to be + * able to read what was just written. + */ endbyte = pos + written_buffered - 1; - err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); + err = filemap_fdatawrite_range(file->f_mapping, pos, endbyte); + if (!err && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(file_inode(file))->runtime_flags)) + err = filemap_fdatawrite_range(file->f_mapping, pos, endbyte); + if (err) + goto out; + err = filemap_fdatawait_range(file->f_mapping, pos, endbyte); if (err) goto out; written += written_buffered; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5a8a749b7e6b..01d223e22bb1 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7015,9 +7015,19 @@ static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, btrfs_put_ordered_extent(ordered); } else { /* Screw you mmap */ - ret = filemap_write_and_wait_range(inode->i_mapping, - lockstart, - lockend); + ret = filemap_fdatawrite_range(inode->i_mapping, + lockstart, + lockend); + if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + ret = filemap_fdatawrite_range(inode->i_mapping, + lockstart, + lockend); + if (ret) + break; + ret = filemap_fdatawait_range(inode->i_mapping, + lockstart, + lockend); if (ret) break; -- 2.20.1