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| author | Chris Mason <chris.mason@oracle.com> | 2008-04-10 10:23:21 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:01 -0400 |
| commit | 16432985920f3c45af82da214e2498f3e2f9066b (patch) | |
| tree | ce05f57eefb1a6f5952c53205ec8a07e93d03b3c /fs/btrfs/file.c | |
| parent | 85d824c4a407ba8dbd897f4e05bbe21bf24cc071 (diff) | |
| download | lwn-16432985920f3c45af82da214e2498f3e2f9066b.tar.gz lwn-16432985920f3c45af82da214e2498f3e2f9066b.zip | |
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 <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/file.c')
| -rw-r--r-- | fs/btrfs/file.c | 11 |
1 files changed, 9 insertions, 2 deletions
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; |