From 16432985920f3c45af82da214e2498f3e2f9066b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 10 Apr 2008 10:23:21 -0400 Subject: Btrfs: Add O_DIRECT read and write (writes == buffered + cache flush) This adds basic O_DIRECT read and write support. In the write case, we just do a normal buffered write followed by a cache flush. O_DIRECT + O_SYNC are required to trigger metadata syncs. In the read case, there is a basic btrfs_get_block call for use by the generic O_DIRECT code. This does honor multi-volume mapping rules but it skips all checksumming. Signed-off-by: Chris Mason --- fs/btrfs/file.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/file.c') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 5fa450452f9b..5b9386452218 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -796,8 +796,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, PAGE_CACHE_SIZE / (sizeof(struct page *))); pinned[0] = NULL; pinned[1] = NULL; - if (file->f_flags & O_DIRECT) - return -EINVAL; pos = *ppos; start_pos = pos; @@ -909,6 +907,15 @@ out_nolock: start_pos, num_written); if (err < 0) num_written = err; + } else if (num_written > 0 && (file->f_flags & O_DIRECT)) { + do_sync_mapping_range(inode->i_mapping, start_pos, + start_pos + num_written - 1, + SYNC_FILE_RANGE_WRITE | + SYNC_FILE_RANGE_WAIT_AFTER); + + invalidate_mapping_pages(inode->i_mapping, + start_pos >> PAGE_CACHE_SHIFT, + (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); } current->backing_dev_info = NULL; return num_written ? num_written : err; -- cgit v1.2.3