Cleanup XDR parsing for LAYOUTGET, GETDEVICEINFO

changes LAYOUTGET and GETDEVICEINFO XDR parsing to:
 - not use vmap, which doesn't work on incoherent archs
 - use xdr_stream parsing for all xdr

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

7 files changed, 230 insertions, 86 deletions

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index ffb54a082f3a..6f8192f4cfc7 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -502,12 +502,33 @@ filelayout_decode_layout(struct pnfs_layout_hdr *flo,
                          struct nfs4_layoutget_res *lgr,
                          struct nfs4_deviceid *id)
 {
-        uint32_t *p = (uint32_t *)lgr->layout.buf;
+        struct xdr_stream stream;
+        struct xdr_buf buf = {
+                .pages =  lgr->layoutp->pages,
+                .page_len =  lgr->layoutp->len,
+                .buflen =  lgr->layoutp->len,
+                .len = lgr->layoutp->len,
+        };
+        struct page *scratch;
+        __be32 *p;
         uint32_t nfl_util;
         int i;
 
         dprintk("%s: set_layout_map Begin\n", __func__);
 
+        scratch = alloc_page(GFP_KERNEL);
+        if (!scratch)
+                return -ENOMEM;
+
+        xdr_init_decode(&stream, &buf, NULL);
+        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+        /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
+         * num_fh (4) */
+        p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
+        if (unlikely(!p))
+                goto out_err;
+
         memcpy(id, p, sizeof(*id));
         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
         print_deviceid(id);
@@ -529,32 +550,46 @@ filelayout_decode_layout(struct pnfs_layout_hdr *flo,
                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
                 fl->pattern_offset);
 
+        if (!fl->num_fh)
+                goto out_err;
+
         fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
                                GFP_KERNEL);
         if (!fl->fh_array)
-                return -ENOMEM;
+                goto out_err;
 
         for (i = 0; i < fl->num_fh; i++) {
                 /* Do we want to use a mempool here? */
                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), GFP_KERNEL);
-                if (!fl->fh_array[i]) {
-                        filelayout_free_fh_array(fl);
-                        return -ENOMEM;
-                }
+                if (!fl->fh_array[i])
+                        goto out_err_free;
+
+                p = xdr_inline_decode(&stream, 4);
+                if (unlikely(!p))
+                        goto out_err_free;
                 fl->fh_array[i]->size = be32_to_cpup(p++);
                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
                         printk(KERN_ERR "Too big fh %d received %d\n",
                                i, fl->fh_array[i]->size);
-                        filelayout_free_fh_array(fl);
-                        return -EIO;
+                        goto out_err_free;
                 }
+
+                p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
+                if (unlikely(!p))
+                        goto out_err_free;
                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
-                p += XDR_QUADLEN(fl->fh_array[i]->size);
                 dprintk("DEBUG: %s: fh len %d\n", __func__,
                         fl->fh_array[i]->size);
         }
 
+        __free_page(scratch);
         return 0;
+
+out_err_free:
+        filelayout_free_fh_array(fl);
+out_err:
+        __free_page(scratch);
+        return -EIO;
 }
 
 static void
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index 68143c162e3b..de5350f2b249 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -261,7 +261,7 @@ out:
  * Currently only support ipv4, and one multi-path address.
  */
 static struct nfs4_pnfs_ds *
-decode_and_add_ds(__be32 **pp, struct inode *inode)
+decode_and_add_ds(struct xdr_stream *streamp, struct inode *inode)
 {
         struct nfs4_pnfs_ds *ds = NULL;
         char *buf;
@@ -269,25 +269,34 @@ decode_and_add_ds(__be32 **pp, struct inode *inode)
         u32 ip_addr, port;
         int nlen, rlen, i;
         int tmp[2];
-        __be32 *r_netid, *r_addr, *p = *pp;
+        __be32 *p;
 
         /* r_netid */
+        p = xdr_inline_decode(streamp, 4);
+        if (unlikely(!p))
+                goto out_err;
         nlen = be32_to_cpup(p++);
-        r_netid = p;
-        p += XDR_QUADLEN(nlen);
 
-        /* r_addr */
-        rlen = be32_to_cpup(p++);
-        r_addr = p;
-        p += XDR_QUADLEN(rlen);
-        *pp = p;
+        p = xdr_inline_decode(streamp, nlen);
+        if (unlikely(!p))
+                goto out_err;
 
         /* Check that netid is "tcp" */
-        if (nlen != 3 ||  memcmp((char *)r_netid, "tcp", 3)) {
+        if (nlen != 3 ||  memcmp((char *)p, "tcp", 3)) {
                 dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
                 goto out_err;
         }
 
+        /* r_addr */
+        p = xdr_inline_decode(streamp, 4);
+        if (unlikely(!p))
+                goto out_err;
+        rlen = be32_to_cpup(p);
+
+        p = xdr_inline_decode(streamp, rlen);
+        if (unlikely(!p))
+                goto out_err;
+
         /* ipv6 length plus port is legal */
         if (rlen > INET6_ADDRSTRLEN + 8) {
                 dprintk("%s: Invalid address, length %d\n", __func__,
@@ -300,7 +309,7 @@ decode_and_add_ds(__be32 **pp, struct inode *inode)
                 goto out_err;
         }
         buf[rlen] = '\0';
-        memcpy(buf, r_addr, rlen);
+        memcpy(buf, p, rlen);
 
         /* replace the port dots with dashes for the in4_pton() delimiter*/
         for (i = 0; i < 2; i++) {
@@ -336,90 +345,154 @@ out_err:
 static struct nfs4_file_layout_dsaddr*
 decode_device(struct inode *ino, struct pnfs_device *pdev)
 {
-        int i, dummy;
+        int i;
         u32 cnt, num;
         u8 *indexp;
-        __be32 *p = (__be32 *)pdev->area, *indicesp;
-        struct nfs4_file_layout_dsaddr *dsaddr;
+        __be32 *p;
+        u8 *stripe_indices;
+        u8 max_stripe_index;
+        struct nfs4_file_layout_dsaddr *dsaddr = NULL;
+        struct xdr_stream stream;
+        struct xdr_buf buf = {
+                .pages = pdev->pages,
+                .page_len = pdev->pglen,
+                .buflen = pdev->pglen,
+                .len = pdev->pglen,
+        };
+        struct page *scratch;
+
+        /* set up xdr stream */
+        scratch = alloc_page(GFP_KERNEL);
+        if (!scratch)
+                goto out_err;
+
+        xdr_init_decode(&stream, &buf, NULL);
+        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 
         /* Get the stripe count (number of stripe index) */
-        cnt = be32_to_cpup(p++);
+        p = xdr_inline_decode(&stream, 4);
+        if (unlikely(!p))
+                goto out_err_free_scratch;
+
+        cnt = be32_to_cpup(p);
         dprintk("%s stripe count  %d\n", __func__, cnt);
         if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
                 printk(KERN_WARNING "%s: stripe count %d greater than "
                        "supported maximum %d\n", __func__,
                         cnt, NFS4_PNFS_MAX_STRIPE_CNT);
-                goto out_err;
+                goto out_err_free_scratch;
+        }
+
+        /* read stripe indices */
+        stripe_indices = kcalloc(cnt, sizeof(u8), GFP_KERNEL);
+        if (!stripe_indices)
+                goto out_err_free_scratch;
+
+        p = xdr_inline_decode(&stream, cnt << 2);
+        if (unlikely(!p))
+                goto out_err_free_stripe_indices;
+
+        indexp = &stripe_indices[0];
+        max_stripe_index = 0;
+        for (i = 0; i < cnt; i++) {
+                *indexp = be32_to_cpup(p++);
+                max_stripe_index = max(max_stripe_index, *indexp);
+                indexp++;
         }
 
         /* Check the multipath list count */
-        indicesp = p;
-        p += XDR_QUADLEN(cnt << 2);
-        num = be32_to_cpup(p++);
+        p = xdr_inline_decode(&stream, 4);
+        if (unlikely(!p))
+                goto out_err_free_stripe_indices;
+
+        num = be32_to_cpup(p);
         dprintk("%s ds_num %u\n", __func__, num);
         if (num > NFS4_PNFS_MAX_MULTI_CNT) {
                 printk(KERN_WARNING "%s: multipath count %d greater than "
                         "supported maximum %d\n", __func__,
                         num, NFS4_PNFS_MAX_MULTI_CNT);
-                goto out_err;
+                goto out_err_free_stripe_indices;
         }
+
+        /* validate stripe indices are all < num */
+        if (max_stripe_index >= num) {
+                printk(KERN_WARNING "%s: stripe index %u >= num ds %u\n",
+                        __func__, max_stripe_index, num);
+                goto out_err_free_stripe_indices;
+        }
+
         dsaddr = kzalloc(sizeof(*dsaddr) +
                         (sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
                         GFP_KERNEL);
         if (!dsaddr)
-                goto out_err;
-
-        dsaddr->stripe_indices = kzalloc(sizeof(u8) * cnt, GFP_KERNEL);
-        if (!dsaddr->stripe_indices)
-                goto out_err_free;
+                goto out_err_free_stripe_indices;
 
         dsaddr->stripe_count = cnt;
+        dsaddr->stripe_indices = stripe_indices;
+        stripe_indices = NULL;
         dsaddr->ds_num = num;
 
         memcpy(&dsaddr->deviceid, &pdev->dev_id, sizeof(pdev->dev_id));
 
-        /* Go back an read stripe indices */
-        p = indicesp;
-        indexp = &dsaddr->stripe_indices[0];
-        for (i = 0; i < dsaddr->stripe_count; i++) {
-                *indexp = be32_to_cpup(p++);
-                if (*indexp >= num)
-                        goto out_err_free;
-                indexp++;
-        }
-        /* Skip already read multipath list count */
-        p++;
-
         for (i = 0; i < dsaddr->ds_num; i++) {
                 int j;
+                u32 mp_count;
+
+                p = xdr_inline_decode(&stream, 4);
+                if (unlikely(!p))
+                        goto out_err_free_deviceid;
 
-                dummy = be32_to_cpup(p++); /* multipath count */
-                if (dummy > 1) {
+                mp_count = be32_to_cpup(p); /* multipath count */
+                if (mp_count > 1) {
                         printk(KERN_WARNING
                                "%s: Multipath count %d not supported, "
                                "skipping all greater than 1\n", __func__,
-                                dummy);
+                                mp_count);
                 }
-                for (j = 0; j < dummy; j++) {
+                for (j = 0; j < mp_count; j++) {
                         if (j == 0) {
-                                dsaddr->ds_list[i] = decode_and_add_ds(&p, ino);
+                                dsaddr->ds_list[i] = decode_and_add_ds(&stream,
+                                        ino);
                                 if (dsaddr->ds_list[i] == NULL)
-                                        goto out_err_free;
+                                        goto out_err_free_deviceid;
                         } else {
                                 u32 len;
                                 /* skip extra multipath */
-                                len = be32_to_cpup(p++);
-                                p += XDR_QUADLEN(len);
-                                len = be32_to_cpup(p++);
-                                p += XDR_QUADLEN(len);
-                                continue;
+
+                                /* read len, skip */
+                                p = xdr_inline_decode(&stream, 4);
+                                if (unlikely(!p))
+                                        goto out_err_free_deviceid;
+                                len = be32_to_cpup(p);
+
+                                p = xdr_inline_decode(&stream, len);
+                                if (unlikely(!p))
+                                        goto out_err_free_deviceid;
+
+                                /* read len, skip */
+                                p = xdr_inline_decode(&stream, 4);
+                                if (unlikely(!p))
+                                        goto out_err_free_deviceid;
+                                len = be32_to_cpup(p);
+
+                                p = xdr_inline_decode(&stream, len);
+                                if (unlikely(!p))
+                                        goto out_err_free_deviceid;
                         }
                 }
         }
+
+        __free_page(scratch);
         return dsaddr;
 
-out_err_free:
+out_err_free_deviceid:
         nfs4_fl_free_deviceid(dsaddr);
+        /* stripe_indicies was part of dsaddr */
+        goto out_err_free_scratch;
+out_err_free_stripe_indices:
+        kfree(stripe_indices);
+out_err_free_scratch:
+        __free_page(scratch);
 out_err:
         dprintk("%s ERROR: returning NULL\n", __func__);
         return NULL;
@@ -498,11 +571,6 @@ get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id)
                         goto out_free;
         }
 
-        /* set pdev->area */
-        pdev->area = vmap(pages, max_pages, VM_MAP, PAGE_KERNEL);
-        if (!pdev->area)
-                goto out_free;
-
         memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
         pdev->layout_type = LAYOUT_NFSV4_1_FILES;
         pdev->pages = pages;
@@ -521,8 +589,6 @@ get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id)
          */
         dsaddr = decode_and_add_device(inode, pdev);
 out_free:
-        if (pdev->area != NULL)
-                vunmap(pdev->area);
         for (i = 0; i < max_pages; i++)
                 __free_page(pages[i]);
         kfree(pages);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 43045fa44710..8f071314e94b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5526,8 +5526,6 @@ static void nfs4_layoutget_release(void *calldata)
         struct nfs4_layoutget *lgp = calldata;
 
         dprintk("--> %s\n", __func__);
-        if (lgp->res.layout.buf != NULL)
-                free_page((unsigned long) lgp->res.layout.buf);
         put_nfs_open_context(lgp->args.ctx);
         kfree(calldata);
         dprintk("<-- %s\n", __func__);
@@ -5559,12 +5557,7 @@ int nfs4_proc_layoutget(struct nfs4_layoutget *lgp)
 
         dprintk("--> %s\n", __func__);
 
-        lgp->res.layout.buf = (void *)__get_free_page(GFP_NOFS);
-        if (lgp->res.layout.buf == NULL) {
-                nfs4_layoutget_release(lgp);
-                return -ENOMEM;
-        }
-
+        lgp->res.layoutp = &lgp->args.layout;
         lgp->res.seq_res.sr_slot = NULL;
         task = rpc_run_task(&task_setup_data);
         if (IS_ERR(task))
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 207d399c8dee..40da65e8fa2a 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2656,6 +2656,10 @@ static void nfs4_xdr_enc_layoutget(struct rpc_rqst *req,
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, NFS_FH(args->inode), &hdr);
         encode_layoutget(xdr, args, &hdr);
+
+        xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2,
+            args->layout.pages, 0, args->layout.pglen);
+
         encode_nops(&hdr);
 }
 
@@ -5022,6 +5026,9 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
         __be32 *p;
         int status;
         u32 layout_count;
+        struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
+        struct kvec *iov = rcvbuf->head;
+        u32 hdrlen, recvd;
 
         status = decode_op_hdr(xdr, OP_LAYOUTGET);
         if (status)
@@ -5038,17 +5045,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
                 return -EINVAL;
         }
 
-        p = xdr_inline_decode(xdr, 24);
+        p = xdr_inline_decode(xdr, 28);
         if (unlikely(!p))
                 goto out_overflow;
         p = xdr_decode_hyper(p, &res->range.offset);
         p = xdr_decode_hyper(p, &res->range.length);
         res->range.iomode = be32_to_cpup(p++);
         res->type = be32_to_cpup(p++);
-
-        status = decode_opaque_inline(xdr, &res->layout.len, (char **)&p);
-        if (unlikely(status))
-                return status;
+        res->layoutp->len = be32_to_cpup(p);
 
         dprintk("%s roff:%lu rlen:%lu riomode:%d, lo_type:0x%x, lo.len:%d\n",
                 __func__,
@@ -5056,12 +5060,18 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
                 (unsigned long)res->range.length,
                 res->range.iomode,
                 res->type,
-                res->layout.len);
+                res->layoutp->len);
+
+        hdrlen = (u8 *) xdr->p - (u8 *) iov->iov_base;
+        recvd = req->rq_rcv_buf.len - hdrlen;
+        if (res->layoutp->len > recvd) {
+                dprintk("NFS: server cheating in layoutget reply: "
+                                "layout len %u > recvd %u\n",
+                                res->layoutp->len, recvd);
+                return -EINVAL;
+        }
 
-        /* nfs4_proc_layoutget allocated a single page */
-        if (res->layout.len > PAGE_SIZE)
-                return -ENOMEM;
-        memcpy(res->layout.buf, p, res->layout.len);
+        xdr_read_pages(xdr, res->layoutp->len);
 
         if (layout_count > 1) {
                 /* We only handle a length one array at the moment.  Any
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 22c2ddbef420..d9ab97269ce6 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -472,6 +472,9 @@ send_layoutget(struct pnfs_layout_hdr *lo,
         struct nfs_server *server = NFS_SERVER(ino);
         struct nfs4_layoutget *lgp;
         struct pnfs_layout_segment *lseg = NULL;
+        struct page **pages = NULL;
+        int i;
+        u32 max_resp_sz, max_pages;
 
         dprintk("--> %s\n", __func__);
 
@@ -479,6 +482,21 @@ send_layoutget(struct pnfs_layout_hdr *lo,
         lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
         if (lgp == NULL)
                 return NULL;
+
+        /* allocate pages for xdr post processing */
+        max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
+        max_pages = max_resp_sz >> PAGE_SHIFT;
+
+        pages = kzalloc(max_pages * sizeof(struct page *), GFP_KERNEL);
+        if (!pages)
+                goto out_err_free;
+
+        for (i = 0; i < max_pages; i++) {
+                pages[i] = alloc_page(GFP_KERNEL);
+                if (!pages[i])
+                        goto out_err_free;
+        }
+
         lgp->args.minlength = NFS4_MAX_UINT64;
         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
         lgp->args.range.iomode = iomode;
@@ -487,6 +505,8 @@ send_layoutget(struct pnfs_layout_hdr *lo,
         lgp->args.type = server->pnfs_curr_ld->id;
         lgp->args.inode = ino;
         lgp->args.ctx = get_nfs_open_context(ctx);
+        lgp->args.layout.pages = pages;
+        lgp->args.layout.pglen = max_pages * PAGE_SIZE;
         lgp->lsegpp = &lseg;
 
         /* Synchronously retrieve layout information from server and
@@ -497,7 +517,26 @@ send_layoutget(struct pnfs_layout_hdr *lo,
                 /* remember that LAYOUTGET failed and suspend trying */
                 set_bit(lo_fail_bit(iomode), &lo->plh_flags);
         }
+
+        /* free xdr pages */
+        for (i = 0; i < max_pages; i++)
+                __free_page(pages[i]);
+        kfree(pages);
+
         return lseg;
+
+out_err_free:
+        /* free any allocated xdr pages, lgp as it's not used */
+        if (pages) {
+                for (i = 0; i < max_pages; i++) {
+                        if (!pages[i])
+                                break;
+                        __free_page(pages[i]);
+                }
+                kfree(pages);
+        }
+        kfree(lgp);
+        return NULL;
 }
 
 bool pnfs_roc(struct inode *ino)
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 33b9ae90c6f7..bc4827202e7a 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -109,7 +109,6 @@ struct pnfs_device {
         unsigned int  layout_type;
         unsigned int  mincount;
         struct page **pages;
-        void          *area;
         unsigned int  pgbase;
         unsigned int  pglen;
 };
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 84f3585c5728..a6e21b10f43d 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -190,8 +190,9 @@ struct nfs4_get_lease_time_res {
 #define PNFS_LAYOUT_MAXSIZE 4096
 
 struct nfs4_layoutdriver_data {
+        struct page **pages;
+        __u32 pglen;
         __u32 len;
-        void *buf;
 };
 
 struct pnfs_layout_range {
@@ -209,6 +210,7 @@ struct nfs4_layoutget_args {
         struct nfs_open_context *ctx;
         struct nfs4_sequence_args seq_args;
         nfs4_stateid stateid;
+        struct nfs4_layoutdriver_data layout;
 };
 
 struct nfs4_layoutget_res {
@@ -216,8 +218,8 @@ struct nfs4_layoutget_res {
         struct pnfs_layout_range range;
         __u32 type;
         nfs4_stateid stateid;
-        struct nfs4_layoutdriver_data layout;
         struct nfs4_sequence_res seq_res;
+        struct nfs4_layoutdriver_data *layoutp;
 };
 
 struct nfs4_layoutget {