| Message ID | 20231013160423.2218093-9-dhowells@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | netfs, afs, cifs: Delegate high-level I/O to netfslib | expand |
On Fri, 2023-10-13 at 17:03 +0100, David Howells wrote: > Add an rsize parameter to netfs_io_request to be filled in by the network > filesystem when the request is initialised. This indicates the maximum > size of a read request that the netfs will honour in that region. > > 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 > --- > fs/afs/file.c | 1 + > fs/ceph/addr.c | 2 ++ > include/linux/netfs.h | 1 + > 3 files changed, 4 insertions(+) > > diff --git a/fs/afs/file.c b/fs/afs/file.c > index 3fea5cd8ef13..3d2e1913ea27 100644 > --- a/fs/afs/file.c > +++ b/fs/afs/file.c > @@ -360,6 +360,7 @@ static int afs_symlink_read_folio(struct file *file, struct folio *folio) > static int afs_init_request(struct netfs_io_request *rreq, struct file *file) > { > rreq->netfs_priv = key_get(afs_file_key(file)); > + rreq->rsize = 4 * 1024 * 1024; > return 0; > } > > diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c > index ced19ff08988..92a5ddcd9a76 100644 > --- a/fs/ceph/addr.c > +++ b/fs/ceph/addr.c > @@ -419,6 +419,8 @@ static int ceph_init_request(struct netfs_io_request *rreq, struct file *file) > struct ceph_netfs_request_data *priv; > int ret = 0; > > + rreq->rsize = 1024 * 1024; > + Holy magic numbers, batman! I think this deserves a comment that explains how you came up with these values. Also, do 9p and cifs not need this for some reason? > if (rreq->origin != NETFS_READAHEAD) > return 0; > > diff --git a/include/linux/netfs.h b/include/linux/netfs.h > index daa431c4148d..02e888c170da 100644 > --- a/include/linux/netfs.h > +++ b/include/linux/netfs.h > @@ -188,6 +188,7 @@ struct netfs_io_request { > struct list_head subrequests; /* Contributory I/O operations */ > void *netfs_priv; /* Private data for the netfs */ > unsigned int debug_id; > + unsigned int rsize; /* Maximum read size (0 for none) */ > atomic_t nr_outstanding; /* Number of ops in progress */ > atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */ > size_t submitted; /* Amount submitted for I/O so far */ >
Jeff Layton <jlayton@kernel.org> wrote: > > + rreq->rsize = 4 * 1024 * 1024; > > return 0; > ... > > + rreq->rsize = 1024 * 1024; > > + > > Holy magic numbers, batman! I think this deserves a comment that > explains how you came up with these values. Actually, that should be set to something like the object size for ceph. > Also, do 9p and cifs not need this for some reason? At this point, cifs doesn't use netfslib, so that's implemented in a later patch in this series. 9p does need setting, but I haven't tested that yet. It probably needs setting to 1MiB as I think that's the maximum the 9p transport can handle. But in the case of cifs, this is actually dynamic, depending on how many credits we can obtain. The same may be true of ceph, though I'm not entirely clear on that as yet. For afs, the maximum [rw]size the protocol supports is actually something like 281350422593565 (ie. (65535-28) * (2^32-1)) minus a few bytes, but that's probably not a good idea. I might be best setting it at something like 256KiB as that's what OpenAFS uses. David
diff --git a/fs/afs/file.c b/fs/afs/file.c index 3fea5cd8ef13..3d2e1913ea27 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -360,6 +360,7 @@ static int afs_symlink_read_folio(struct file *file, struct folio *folio) static int afs_init_request(struct netfs_io_request *rreq, struct file *file) { rreq->netfs_priv = key_get(afs_file_key(file)); + rreq->rsize = 4 * 1024 * 1024; return 0; } diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index ced19ff08988..92a5ddcd9a76 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -419,6 +419,8 @@ static int ceph_init_request(struct netfs_io_request *rreq, struct file *file) struct ceph_netfs_request_data *priv; int ret = 0; + rreq->rsize = 1024 * 1024; + if (rreq->origin != NETFS_READAHEAD) return 0; diff --git a/include/linux/netfs.h b/include/linux/netfs.h index daa431c4148d..02e888c170da 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -188,6 +188,7 @@ struct netfs_io_request { struct list_head subrequests; /* Contributory I/O operations */ void *netfs_priv; /* Private data for the netfs */ unsigned int debug_id; + unsigned int rsize; /* Maximum read size (0 for none) */ atomic_t nr_outstanding; /* Number of ops in progress */ atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */ size_t submitted; /* Amount submitted for I/O so far */
Add an rsize parameter to netfs_io_request to be filled in by the network filesystem when the request is initialised. This indicates the maximum size of a read request that the netfs will honour in that region. 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 --- fs/afs/file.c | 1 + fs/ceph/addr.c | 2 ++ include/linux/netfs.h | 1 + 3 files changed, 4 insertions(+)