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| author | Mike Snitzer <snitzer@kernel.org> | 2024-11-15 20:40:53 -0500 |
|---|---|---|
| committer | Anna Schumaker <anna.schumaker@oracle.com> | 2025-01-14 17:04:02 -0500 |
| commit | 3feec68563dda59517f83d19123aa287a1dfd068 (patch) | |
| tree | 00b3bddf355513cded25b02e3601d895b0243e6f /fs/nfs/direct.c | |
| parent | 49fd4e34751e90e6df009b70cd0659dc839e7ca8 (diff) | |
| download | linux-next-3feec68563dda59517f83d19123aa287a1dfd068.tar.gz linux-next-3feec68563dda59517f83d19123aa287a1dfd068.zip | |
nfs/localio: add direct IO enablement with sync and async IO support
This commit simply adds the required O_DIRECT plumbing. It doesn't
address the fact that NFS doesn't ensure all writes are page aligned
(nor device logical block size aligned as required by O_DIRECT).
Because NFS will read-modify-write for IO that isn't aligned, LOCALIO
will not use O_DIRECT semantics by default if/when an application
requests the use of O_DIRECT. Allow the use of O_DIRECT semantics by:
1: Adding a flag to the nfs_pgio_header struct to allow the NFS
O_DIRECT layer to signal that O_DIRECT was used by the application
2: Adding a 'localio_O_DIRECT_semantics' NFS module parameter that
when enabled will cause LOCALIO to use O_DIRECT semantics (this may
cause IO to fail if applications do not properly align their IO).
This commit is derived from code developed by Weston Andros Adamson.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Diffstat (limited to 'fs/nfs/direct.c')
| -rw-r--r-- | fs/nfs/direct.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index b08dbe96bc57..f45beea92d03 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -303,6 +303,7 @@ static void nfs_read_sync_pgio_error(struct list_head *head, int error) static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr) { get_dreq(hdr->dreq); + set_bit(NFS_IOHDR_ODIRECT, &hdr->flags); } static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = { |