diff options
| author | Mike Snitzer <snitzer@kernel.org> | 2025-11-11 09:59:31 -0500 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2025-12-01 09:57:10 -0500 |
| commit | 06c5c97293e3fca99ce15da157068edf45a7c6e4 (patch) | |
| tree | 1493d0a45a2cc0077914c18d91b9027c2537f43e /fs/nfsd/debugfs.c | |
| parent | e3e8e176ca4876e6212582022ad80835dddc9de4 (diff) | |
NFSD: Implement NFSD_IO_DIRECT for NFS WRITE
When NFSD_IO_DIRECT is selected via the
/sys/kernel/debug/nfsd/io_cache_write experimental tunable, split
incoming unaligned NFS WRITE requests into a prefix, middle and
suffix segment, as needed. The middle segment is now DIO-aligned and
the prefix and/or suffix are unaligned. Synchronous buffered IO is
used for the unaligned segments, and IOCB_DIRECT is used for the
middle DIO-aligned extent.
Although IOCB_DIRECT avoids the use of the page cache, by itself it
doesn't guarantee data durability. For UNSTABLE WRITE requests,
durability is obtained by a subsequent NFS COMMIT request.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Co-developed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd/debugfs.c')
| -rw-r--r-- | fs/nfsd/debugfs.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfsd/debugfs.c b/fs/nfsd/debugfs.c index 00eb1ecef6ac..7f44689e0a53 100644 --- a/fs/nfsd/debugfs.c +++ b/fs/nfsd/debugfs.c @@ -108,6 +108,7 @@ static int nfsd_io_cache_write_set(void *data, u64 val) switch (val) { case NFSD_IO_BUFFERED: case NFSD_IO_DONTCACHE: + case NFSD_IO_DIRECT: nfsd_io_cache_write = val; break; default: |