NFSv4: Implement the fs_locations function call
NFSv4 allows for the fact that filesystems may be replicated across
several servers or that they may be migrated to a backup server in case of
failure of the primary server.
fs_locations is an NFSv4 operation for retrieving information about the
location of migrated and/or replicated filesystems.
Based on an initial implementation by Jiaying Zhang <jiayingz@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 0d57946..7add313 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -411,6 +411,15 @@
#define NFS4_dec_setacl_sz (compound_decode_hdr_maxsz + \
decode_putfh_maxsz + \
op_decode_hdr_maxsz + nfs4_fattr_bitmap_maxsz)
+#define NFS4_enc_fs_locations_sz \
+ (compound_encode_hdr_maxsz + \
+ encode_putfh_maxsz + \
+ encode_getattr_maxsz)
+#define NFS4_dec_fs_locations_sz \
+ (compound_decode_hdr_maxsz + \
+ decode_putfh_maxsz + \
+ op_decode_hdr_maxsz + \
+ nfs4_fattr_bitmap_maxsz)
static struct {
unsigned int mode;
@@ -2003,6 +2012,38 @@
}
/*
+ * Encode FS_LOCATIONS request
+ */
+static int nfs4_xdr_enc_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs4_fs_locations_arg *args)
+{
+ struct xdr_stream xdr;
+ struct compound_hdr hdr = {
+ .nops = 3,
+ };
+ struct rpc_auth *auth = req->rq_task->tk_auth;
+ int replen;
+ int status;
+
+ xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+ encode_compound_hdr(&xdr, &hdr);
+ if ((status = encode_putfh(&xdr, args->dir_fh)) != 0)
+ goto out;
+ if ((status = encode_lookup(&xdr, args->name)) != 0)
+ goto out;
+ if ((status = encode_getfattr(&xdr, args->bitmask)) != 0)
+ goto out;
+ /* set up reply
+ * toplevel_status + taglen + rescount + OP_PUTFH + status
+ * + OP_LOOKUP + status + OP_GETATTR + status = 7
+ */
+ replen = (RPC_REPHDRSIZE + auth->au_rslack + 7) << 2;
+ xdr_inline_pages(&req->rq_rcv_buf, replen, &args->page,
+ 0, PAGE_SIZE);
+out:
+ return status;
+}
+
+/*
* START OF "GENERIC" DECODE ROUTINES.
* These may look a little ugly since they are imported from a "generic"
* set of XDR encode/decode routines which are intended to be shared by
@@ -2036,7 +2077,7 @@
} \
} while (0)
-static int decode_opaque_inline(struct xdr_stream *xdr, uint32_t *len, char **string)
+static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)
{
uint32_t *p;
@@ -2087,7 +2128,7 @@
static int decode_ace(struct xdr_stream *xdr, void *ace, struct nfs4_client *clp)
{
uint32_t *p;
- uint32_t strlen;
+ unsigned int strlen;
char *str;
READ_BUF(12);
@@ -2336,6 +2377,45 @@
return status;
}
+static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fs_locations *res)
+{
+ int n;
+ uint32_t *p;
+ int status = -EIO;
+
+ if (unlikely(bitmap[0] & (FATTR4_WORD0_FS_LOCATIONS -1U)))
+ goto out;
+ status = 0;
+ if (unlikely(!(bitmap[0] & FATTR4_WORD0_FS_LOCATIONS)))
+ goto out;
+ status = decode_opaque_inline(xdr, &res->fs_pathlen, &res->fs_path);
+ if (unlikely(status != 0))
+ goto out;
+ READ_BUF(4);
+ READ32(n);
+ if (n <= 0)
+ goto out_eio;
+ res->nlocations = 0;
+ while (res->nlocations < n) {
+ struct nfs_fs_location *loc = &res->locations[res->nlocations];
+
+ status = decode_opaque_inline(xdr, &loc->serverlen, &loc->server);
+ if (unlikely(status != 0))
+ goto out_eio;
+ status = decode_opaque_inline(xdr, &loc->rootpathlen, &loc->rootpath);
+ if (unlikely(status != 0))
+ goto out_eio;
+ if (res->nlocations < NFS_FS_LOCATIONS_MAXENTRIES)
+ res->nlocations++;
+ }
+out:
+ dprintk("%s: fs_locations done, error = %d\n", __FUNCTION__, status);
+ return status;
+out_eio:
+ status = -EIO;
+ goto out;
+}
+
static int decode_attr_maxfilesize(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
{
uint32_t *p;
@@ -2867,6 +2947,10 @@
goto xdr_error;
if ((status = decode_attr_fileid(xdr, bitmap, &fattr->fileid)) != 0)
goto xdr_error;
+ if ((status = decode_attr_fs_locations(xdr, bitmap, container_of(fattr,
+ struct nfs_fs_locations,
+ fattr))) != 0)
+ goto xdr_error;
if ((status = decode_attr_mode(xdr, bitmap, &fattr->mode)) != 0)
goto xdr_error;
fattr->mode |= fmode;
@@ -4210,6 +4294,29 @@
return status;
}
+/*
+ * FS_LOCATIONS request
+ */
+static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, uint32_t *p, struct nfs_fs_locations *res)
+{
+ struct xdr_stream xdr;
+ struct compound_hdr hdr;
+ int status;
+
+ xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
+ status = decode_compound_hdr(&xdr, &hdr);
+ if (status != 0)
+ goto out;
+ if ((status = decode_putfh(&xdr)) != 0)
+ goto out;
+ if ((status = decode_lookup(&xdr)) != 0)
+ goto out;
+ xdr_enter_page(&xdr, PAGE_SIZE);
+ status = decode_getfattr(&xdr, &res->fattr, res->server);
+out:
+ return status;
+}
+
uint32_t *nfs4_decode_dirent(uint32_t *p, struct nfs_entry *entry, int plus)
{
uint32_t bitmap[2] = {0};
@@ -4381,6 +4488,7 @@
PROC(DELEGRETURN, enc_delegreturn, dec_delegreturn),
PROC(GETACL, enc_getacl, dec_getacl),
PROC(SETACL, enc_setacl, dec_setacl),
+ PROC(FS_LOCATIONS, enc_fs_locations, dec_fs_locations),
};
struct rpc_version nfs_version4 = {