[PATCH] use kmap_atomic instaed of kmap in NFS client

From: Chuck Lever (cel@citi.umich.edu)
Date: Wed Dec 18 2002 - 18:19:43 EST


Description:
  andrew morton suggested there are places in the NFS client that could
  make use of kmap_atomic instead of vanilla kmap in order to improve
  scalability on 8-way and higher SMP systems.

Apply Against:
  2.5.52

Test status:
  Passes all Connectathon '02 tests with v2 and v3, UDP and TCP; passes
  NFS torture tests on a UP HIGHMEM x86 system.

diff -Naurp 00-stock/fs/nfs/dir.c 01-kmap_atomic/fs/nfs/dir.c
--- 00-stock/fs/nfs/dir.c Sun Dec 15 21:07:57 2002
+++ 01-kmap_atomic/fs/nfs/dir.c Wed Dec 18 17:22:06 2002
@@ -208,7 +208,7 @@ int find_dirent_page(nfs_readdir_descrip
 
         /* NOTE: Someone else may have changed the READDIRPLUS flag */
         desc->page = page;
- desc->ptr = kmap(page);
+ desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
         status = find_dirent(desc, page);
         if (status < 0)
                 dir_page_release(desc);
@@ -345,7 +345,7 @@ int uncached_readdir(nfs_readdir_descrip
                                                 NFS_SERVER(inode)->dtsize,
                                                 desc->plus);
         desc->page = page;
- desc->ptr = kmap(page);
+ desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
         if (desc->error >= 0) {
                 if ((status = dir_decode(desc)) == 0)
                         desc->entry->prev_cookie = desc->target;
@@ -717,9 +717,9 @@ int nfs_cached_lookup(struct inode *dir,
 
                 res = -EIO;
                 if (PageUptodate(page)) {
- desc.ptr = kmap(page);
+ desc.ptr = kmap_atomic(page, KM_USER0);
                         res = find_dirent_name(&desc, page, dentry);
- kunmap(page);
+ kunmap_atomic(desc.ptr, KM_USER0);
                 }
                 page_cache_release(page);
 
diff -Naurp 00-stock/fs/nfs/nfs2xdr.c 01-kmap_atomic/fs/nfs/nfs2xdr.c
--- 00-stock/fs/nfs/nfs2xdr.c Sun Dec 15 21:07:53 2002
+++ 01-kmap_atomic/fs/nfs/nfs2xdr.c Wed Dec 18 17:22:06 2002
@@ -378,7 +378,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req,
         int hdrlen, recvd;
         int status, nr;
         unsigned int len, pglen;
- u32 *end, *entry;
+ u32 *end, *entry, *kaddr;
 
         if ((status = ntohl(*p++)))
                 return -nfs_stat_to_errno(status);
@@ -398,7 +398,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req,
         if (pglen > recvd)
                 pglen = recvd;
         page = rcvbuf->pages;
- p = kmap(*page);
+ kaddr = p = (u32 *)kmap_atomic(*page, KM_USER0);
         end = (u32 *)((char *)p + pglen);
         entry = p;
         for (nr = 0; *p++; nr++) {
@@ -419,7 +419,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req,
         if (!nr && (entry[0] != 0 || entry[1] == 0))
                 goto short_pkt;
  out:
- kunmap(*page);
+ kunmap_atomic(kaddr, KM_USER0);
         return nr;
  short_pkt:
         entry[0] = entry[1] = 0;
@@ -430,8 +430,8 @@ nfs_xdr_readdirres(struct rpc_rqst *req,
         }
         goto out;
 err_unmap:
- kunmap(*page);
- return -errno_NFSERR_IO;
+ nr = -errno_NFSERR_IO;
+ goto out;
 }
 
 u32 *
@@ -542,7 +542,7 @@ nfs_xdr_readlinkres(struct rpc_rqst *req
                 xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
         }
 
- strlen = (u32*)kmap(rcvbuf->pages[0]);
+ strlen = (u32*)kmap_atomic(rcvbuf->pages[0], KM_USER0);
         /* Convert length of symlink */
         len = ntohl(*strlen);
         if (len > rcvbuf->page_len)
@@ -551,7 +551,7 @@ nfs_xdr_readlinkres(struct rpc_rqst *req
         /* NULL terminate the string we got */
         string = (char *)(strlen + 1);
         string[len] = 0;
- kunmap(rcvbuf->pages[0]);
+ kunmap_atomic(strlen, KM_USER0);
         return 0;
 }
 
diff -Naurp 00-stock/fs/nfs/nfs3xdr.c 01-kmap_atomic/fs/nfs/nfs3xdr.c
--- 00-stock/fs/nfs/nfs3xdr.c Sun Dec 15 21:08:24 2002
+++ 01-kmap_atomic/fs/nfs/nfs3xdr.c Wed Dec 18 17:22:06 2002
@@ -488,7 +488,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req
         int hdrlen, recvd;
         int status, nr;
         unsigned int len, pglen;
- u32 *entry, *end;
+ u32 *entry, *end, *kaddr;
 
         status = ntohl(*p++);
         /* Decode post_op_attrs */
@@ -518,7 +518,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req
         if (pglen > recvd)
                 pglen = recvd;
         page = rcvbuf->pages;
- p = kmap(*page);
+ kaddr = p = (u32 *)kmap_atomic(*page, KM_USER0);
         end = (u32 *)((char *)p + pglen);
         entry = p;
         for (nr = 0; *p++; nr++) {
@@ -563,7 +563,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req
         if (!nr && (entry[0] != 0 || entry[1] == 0))
                 goto short_pkt;
  out:
- kunmap(*page);
+ kunmap_atomic(kaddr, KM_USER0);
         return nr;
  short_pkt:
         entry[0] = entry[1] = 0;
@@ -574,8 +574,8 @@ nfs3_xdr_readdirres(struct rpc_rqst *req
         }
         goto out;
 err_unmap:
- kunmap(*page);
- return -errno_NFSERR_IO;
+ nr = -errno_NFSERR_IO;
+ goto out;
 }
 
 u32 *
@@ -738,7 +738,7 @@ nfs3_xdr_readlinkres(struct rpc_rqst *re
                 xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
         }
 
- strlen = (u32*)kmap(rcvbuf->pages[0]);
+ strlen = (u32*)kmap_atomic(rcvbuf->pages[0], KM_USER0);
         /* Convert length of symlink */
         len = ntohl(*strlen);
         if (len > rcvbuf->page_len)
@@ -747,7 +747,7 @@ nfs3_xdr_readlinkres(struct rpc_rqst *re
         /* NULL terminate the string we got */
         string = (char *)(strlen + 1);
         string[len] = 0;
- kunmap(rcvbuf->pages[0]);
+ kunmap_atomic(strlen, KM_USER0);
         return 0;
 }
 
diff -Naurp 00-stock/fs/nfs/nfs4proc.c 01-kmap_atomic/fs/nfs/nfs4proc.c
--- 00-stock/fs/nfs/nfs4proc.c Sun Dec 15 21:08:14 2002
+++ 01-kmap_atomic/fs/nfs/nfs4proc.c Wed Dec 18 17:22:06 2002
@@ -447,7 +447,7 @@ nfs4_setup_readdir(struct nfs4_compound
          * when talking to the server, we always send cookie 0
          * instead of 1 or 2.
          */
- start = p = (u32 *)kmap(*pages);
+ start = p = (u32 *)kmap_atomic(*pages, KM_USER0);
         
         if (cookie == 0) {
                 *p++ = xdr_one; /* next */
@@ -475,7 +475,7 @@ nfs4_setup_readdir(struct nfs4_compound
 
         readdir->rd_pgbase = (char *)p - (char *)start;
         readdir->rd_count -= readdir->rd_pgbase;
- kunmap(*pages);
+ kunmap_atomic(start, KM_USER0);
 }
 
 static void
diff -Naurp 00-stock/fs/nfs/nfs4xdr.c 01-kmap_atomic/fs/nfs/nfs4xdr.c
--- 00-stock/fs/nfs/nfs4xdr.c Sun Dec 15 21:08:24 2002
+++ 01-kmap_atomic/fs/nfs/nfs4xdr.c Wed Dec 18 17:31:28 2002
@@ -1410,7 +1410,7 @@ decode_readdir(struct xdr_stream *xdr, s
         struct page *page = *rcvbuf->pages;
         struct iovec *iov = rcvbuf->head;
         unsigned int nr, pglen = rcvbuf->page_len;
- uint32_t *end, *entry, *p;
+ uint32_t *end, *entry, *p, *kaddr;
         uint32_t len, attrlen, word;
         int i, hdrlen, recvd, status;
 
@@ -1434,7 +1434,7 @@ decode_readdir(struct xdr_stream *xdr, s
                 pglen = recvd;
 
         BUG_ON(pglen + readdir->rd_pgbase > PAGE_CACHE_SIZE);
- p = (uint32_t *) kmap(page);
+ kaddr = p = (uint32_t *) kmap_atomic(page, KM_USER0);
         end = (uint32_t *) ((char *)p + pglen + readdir->rd_pgbase);
         entry = p;
         for (nr = 0; *p++; nr++) {
@@ -1480,7 +1480,7 @@ decode_readdir(struct xdr_stream *xdr, s
         if (!nr && (entry[0] != 0 || entry[1] == 0))
                 goto short_pkt;
 out:
- kunmap(page);
+ kunmap_atomic(kaddr, KM_USER0);
         return 0;
 short_pkt:
         entry[0] = entry[1] = 0;
@@ -1491,7 +1491,7 @@ short_pkt:
         }
         goto out;
 err_unmap:
- kunmap(page);
+ kunmap_atomic(kaddr, KM_USER0);
         return -errno_NFSERR_IO;
 }
 
@@ -1522,18 +1522,18 @@ decode_readlink(struct xdr_stream *xdr,
          * and and null-terminate the text (the VFS expects
          * null-termination).
          */
- strlen = (uint32_t *) kmap(rcvbuf->pages[0]);
+ strlen = (uint32_t *) kmap_atomic(rcvbuf->pages[0], KM_USER0);
         len = ntohl(*strlen);
         if (len > PAGE_CACHE_SIZE - 5) {
                 printk(KERN_WARNING "nfs: server returned giant symlink!\n");
- kunmap(rcvbuf->pages[0]);
+ kunmap_atomic(strlen, KM_USER0);
                 return -EIO;
         }
         *strlen = len;
 
         string = (char *)(strlen + 1);
         string[len] = '\0';
- kunmap(rcvbuf->pages[0]);
+ kunmap_atomic(strlen, KM_USER0);
         return 0;
 }
 
diff -Naurp 00-stock/fs/nfs/read.c 01-kmap_atomic/fs/nfs/read.c
--- 00-stock/fs/nfs/read.c Sun Dec 15 21:07:42 2002
+++ 01-kmap_atomic/fs/nfs/read.c Wed Dec 18 17:22:06 2002
@@ -118,12 +118,8 @@ nfs_readpage_sync(struct file *file, str
                         break;
         } while (count);
 
- if (count) {
- char *kaddr = kmap(page);
- memset(kaddr + offset, 0, count);
- kunmap(page);
- }
- flush_dcache_page(page);
+ if (count)
+ memclear_highpage_flush(page, offset, count);
         SetPageUptodate(page);
         if (PageError(page))
                 ClearPageError(page);
@@ -272,12 +268,9 @@ nfs_readpage_result(struct rpc_task *tas
 
                 if (task->tk_status >= 0) {
                         if (count < PAGE_CACHE_SIZE) {
- char *p = kmap(page);
-
- if (count < req->wb_bytes)
- memset(p + req->wb_offset + count, 0,
+ memclear_highpage_flush(page,
+ req->wb_offset + count,
                                                         req->wb_bytes - count);
- kunmap(page);
 
                                 if (eof ||
                                     ((fattr->valid & NFS_ATTR_FATTR) &&
@@ -293,7 +286,6 @@ nfs_readpage_result(struct rpc_task *tas
                         }
                 } else
                         SetPageError(page);
- flush_dcache_page(page);
                 unlock_page(page);
 
                 dprintk("NFS: read (%s/%Ld %d@%Ld)\n",
diff -Naurp 00-stock/net/sunrpc/xdr.c 01-kmap_atomic/net/sunrpc/xdr.c
--- 00-stock/net/sunrpc/xdr.c Sun Dec 15 21:08:13 2002
+++ 01-kmap_atomic/net/sunrpc/xdr.c Wed Dec 18 17:22:06 2002
@@ -306,6 +306,7 @@ xdr_partial_copy_from_skb(struct xdr_buf
                                 len = pglen;
                         ret = copy_actor(desc, kaddr, len);
                 }
+ flush_dcache_page(*ppage);
                 kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA);
                 if (ret != len || !desc->count)
                         return;

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This archive was generated by hypermail 2b29 : Mon Dec 23 2002 - 22:00:21 EST