On Tue, Jun 07, 2016 at 06:38:10AM -0400, Jeff Layton wrote:
> From: Tigran Mkrtchyan <tigran.mkrtchyan@xxxxxxx>
>
> current NFSv4.1/pNFS client assumes that MDS supports
> only one layout type. While it's true for most existing servers,
> nevertheless, this can be change in the near future.
>
> This patch is an attempt to multi layouttype MDS support. To make
> it possible for such servers to function with existing clients,
> server must always send default layout type first in the list. The
> client starts processing layout types starting from the second element
> and will fall back to the wfirst one, if none of presented types
> is supported.
I don't follow this explanation.
Also, it gets overridden by the following patch.
How about making this patch purely a preperatory patch that puts the
necessary code in place without changing behavior, and leaving any
discussion of ordering to the following patch.
So, change set_pnfs_layoutdriver to take an array, but have it just do
the trivial thing (take the first element) till the following patch.
--b.
>
> Testing done:
>
> - started a server with nfs4_file and flex_file layout
> - new kernel picked flexr_-file layout
> - old complained about multiple layout types and proceeded nfs4_file layout
>
> Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@xxxxxxx>
> ---
> fs/nfs/client.c | 2 +-
> fs/nfs/nfs4xdr.c | 23 ++++++++++-------------
> fs/nfs/pnfs.c | 45 ++++++++++++++++++++++++++++++++-------------
> fs/nfs/pnfs.h | 2 +-
> include/linux/nfs_xdr.h | 8 +++++++-
> 5 files changed, 51 insertions(+), 29 deletions(-)
>
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index 0c96528db94a..067f489aab3f 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -787,7 +787,7 @@ int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs
> }
>
> fsinfo.fattr = fattr;
> - fsinfo.layouttype = 0;
> + memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
> error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
> if (error < 0)
> goto out_error;
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index 661e753fe1c9..b2c698499ad9 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -4720,14 +4720,13 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
> }
>
> /*
> - * Decode potentially multiple layout types. Currently we only support
> - * one layout driver per file system.
> + * Decode potentially multiple layout types.
> */
> -static int decode_first_pnfs_layout_type(struct xdr_stream *xdr,
> +static int decode_pnfs_layout_types(struct xdr_stream *xdr,
> uint32_t *layouttype)
> {
> __be32 *p;
> - int num;
> + uint32_t num, i;
>
> p = xdr_inline_decode(xdr, 4);
> if (unlikely(!p))
> @@ -4736,18 +4735,17 @@ static int decode_first_pnfs_layout_type(struct xdr_stream *xdr,
>
> /* pNFS is not supported by the underlying file system */
> if (num == 0) {
> - *layouttype = 0;
> return 0;
> }
> - if (num > 1)
> - printk(KERN_INFO "NFS: %s: Warning: Multiple pNFS layout "
> - "drivers per filesystem not supported\n", __func__);
> + if (num > NFS_MAX_LAYOUT_TYPES)
> + printk(KERN_INFO "NFS: %s: Warning: Too many (%d) pNFS layout types\n", __func__, num);
>
> /* Decode and set first layout type, move xdr->p past unused types */
> p = xdr_inline_decode(xdr, num * 4);
> if (unlikely(!p))
> goto out_overflow;
> - *layouttype = be32_to_cpup(p);
> + for(i = 0; i < num && i < NFS_MAX_LAYOUT_TYPES; i++)
> + layouttype[i] = be32_to_cpup(p++);
> return 0;
> out_overflow:
> print_overflow_msg(__func__, xdr);
> @@ -4767,10 +4765,9 @@ static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
> if (unlikely(bitmap[1] & (FATTR4_WORD1_FS_LAYOUT_TYPES - 1U)))
> return -EIO;
> if (bitmap[1] & FATTR4_WORD1_FS_LAYOUT_TYPES) {
> - status = decode_first_pnfs_layout_type(xdr, layouttype);
> + status = decode_pnfs_layout_types(xdr, layouttype);
> bitmap[1] &= ~FATTR4_WORD1_FS_LAYOUT_TYPES;
> - } else
> - *layouttype = 0;
> + }
> return status;
> }
>
> @@ -4851,7 +4848,7 @@ static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
> status = decode_attr_time_delta(xdr, bitmap, &fsinfo->time_delta);
> if (status != 0)
> goto xdr_error;
> - status = decode_attr_pnfstype(xdr, bitmap, &fsinfo->layouttype);
> + status = decode_attr_pnfstype(xdr, bitmap, fsinfo->layouttype);
> if (status != 0)
> goto xdr_error;
>
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index 0c7e0d45a4de..b02cad9c04bf 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -102,32 +102,51 @@ unset_pnfs_layoutdriver(struct nfs_server *nfss)
> * Try to set the server's pnfs module to the pnfs layout type specified by id.
> * Currently only one pNFS layout driver per filesystem is supported.
> *
> - * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
> + * @ids array of layout types supported by MDS.
> */
> void
> set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
> - u32 id)
> + u32 *ids)
> {
> struct pnfs_layoutdriver_type *ld_type = NULL;
> + u32 id;
> + int i;
>
> - if (id == 0)
> - goto out_no_driver;
> if (!(server->nfs_client->cl_exchange_flags &
> (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
> - printk(KERN_ERR "NFS: %s: id %u cl_exchange_flags 0x%x\n",
> - __func__, id, server->nfs_client->cl_exchange_flags);
> + printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
> + __func__, server->nfs_client->cl_exchange_flags);
> goto out_no_driver;
> }
> - ld_type = find_pnfs_driver(id);
> - if (!ld_type) {
> + /*
> + * If server supports more than one layout types.
> + * By assuming, that server will put 'common default' as the first
> + * entry, try all following entries ibefore and fall back to the default
> + * if we did not found a matching one.
> + */
> + for(i = 1; i < NFS_MAX_LAYOUT_TYPES && ids[i] != 0; i++) {
> + id = ids[i];
> request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
> ld_type = find_pnfs_driver(id);
> - if (!ld_type) {
> - dprintk("%s: No pNFS module found for %u.\n",
> - __func__, id);
> - goto out_no_driver;
> - }
> + if(ld_type)
> + goto found_module;
> +
> + dprintk("%s: No pNFS module found for %u.\n", __func__, id);
> + }
> +
> + /*
> + * no other layout types found. Try default one.
> + */
> + id = ids[0];
> + request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
> + ld_type = find_pnfs_driver(id);
> +
> + if (!ld_type) {
> + dprintk("%s: No pNFS module found for %u.\n", __func__, id);
> + goto out_no_driver;
> }
> +
> +found_module:
> server->pnfs_curr_ld = ld_type;
> if (ld_type->set_layoutdriver
> && ld_type->set_layoutdriver(server, mntfh)) {
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index b21bd0bee784..7d74e3da1d69 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -236,7 +236,7 @@ void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
> void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
> void pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg);
>
> -void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
> +void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32 *);
> void unset_pnfs_layoutdriver(struct nfs_server *);
> void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
> int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index c304a11b5b1a..15f7979494b2 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -125,6 +125,12 @@ struct nfs_fattr {
> | NFS_ATTR_FATTR_V4_SECURITY_LABEL)
>
> /*
> + * Maximal number of supported layout drivers.
> + */
> +#define NFS_MAX_LAYOUT_TYPES 8
> +
> +
> +/*
> * Info on the file system
> */
> struct nfs_fsinfo {
> @@ -139,7 +145,7 @@ struct nfs_fsinfo {
> __u64 maxfilesize;
> struct timespec time_delta; /* server time granularity */
> __u32 lease_time; /* in seconds */
> - __u32 layouttype; /* supported pnfs layout driver */
> + __u32 layouttype[NFS_MAX_LAYOUT_TYPES]; /* supported pnfs layout driver */
> __u32 blksize; /* preferred pnfs io block size */
> __u32 clone_blksize; /* granularity of a CLONE operation */
> };
> --
> 2.5.5
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
