diff options
| author |   David Howells <dhowells@redhat.com> | 2022-01-14 17:39:55 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2023-12-28 09:45:23 +0000 |
| commit | 016dc8516aec8719641e7aaaacd78d344759178e (patch) | |
| tree | 15cc93a54ddfa05ffc558b1bff50aa655ce926ce /fs/netfs/objects.c | |
| parent | netfs: Allocate multipage folios in the writepath (diff) | |
| download | wireguard-linux-016dc8516aec8719641e7aaaacd78d344759178e.tar.xz wireguard-linux-016dc8516aec8719641e7aaaacd78d344759178e.zip | |
netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing. The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.
The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method. Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.
Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined. As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.
In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Diffstat (limited to 'fs/netfs/objects.c')
| -rw-r--r-- | fs/netfs/objects.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 3aa0bfbc04ec..7153f24e8034 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -20,7 +20,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, struct inode *inode = file ? file_inode(file) : mapping->host; struct netfs_inode *ctx = netfs_inode(inode); struct netfs_io_request *rreq; - bool cached = netfs_is_cache_enabled(ctx); + bool is_dio = (origin == NETFS_DIO_READ); + bool cached = is_dio && netfs_is_cache_enabled(ctx); int ret; rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request), @@ -42,6 +43,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); if (cached) __set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags); + if (file && file->f_flags & O_NONBLOCK) + __set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags); if (rreq->netfs_ops->init_request) { ret = rreq->netfs_ops->init_request(rreq, file); if (ret < 0) { |