On 09/27/2010 07:47 AM, Trond Myklebust wrote:
> Agreed: fs/nfs/dir.c needs to #include <vmalloc.h> in order to use those
> functions. Bryan, can you please fix that up?
No problem. An updated patch is pasted below.
-Bryan
We can use vmapped pages to read more information from the network at once.
This will reduce the number of calls needed to complete a readdir.
Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index e734072..9e2fcc8 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -901,8 +901,8 @@ static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *
server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
- if (server->dtsize > PAGE_CACHE_SIZE)
- server->dtsize = PAGE_CACHE_SIZE;
+ if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
+ server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
if (server->dtsize > server->rsize)
server->dtsize = server->rsize;
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 8a54a07..207cc47 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -33,6 +33,7 @@
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/sched.h>
+#include <linux/vmalloc.h>
#include "nfs4_fs.h"
#include "delegation.h"
@@ -326,7 +327,7 @@ out:
/* Fill a page with xdr information before transferring to the cache page */
static
-int nfs_readdir_xdr_filler(struct page *xdr_page, nfs_readdir_descriptor_t *desc,
+int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
struct nfs_entry *entry, struct file *file, struct inode *inode)
{
struct rpc_cred *cred = nfs_file_cred(file);
@@ -336,7 +337,7 @@ int nfs_readdir_xdr_filler(struct page *xdr_page, nfs_readdir_descriptor_t *desc
again:
timestamp = jiffies;
gencount = nfs_inc_attr_generation_counter();
- error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, xdr_page,
+ error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
NFS_SERVER(inode)->dtsize, desc->plus);
if (error < 0) {
/* We requested READDIRPLUS, but the server doesn't grok it */
@@ -437,22 +438,63 @@ out:
/* Perform conversion from xdr to cache array */
static
void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
- struct page *xdr_page, struct page *page)
+ void *xdr_page, struct page *page)
{
- __be32 *ptr = kmap(xdr_page);
+ __be32 *ptr = xdr_page;
while (xdr_decode(desc, entry, &ptr) == 0) {
if (nfs_readdir_add_to_array(entry, page) == -1)
break;
if (desc->plus == 1)
nfs_prime_dcache(desc->file->f_path.dentry, entry);
}
- kunmap(xdr_page);
+}
+
+static
+void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
+{
+ unsigned int i;
+ for (i = 0; i < npages; i++)
+ put_page(pages[i]);
+}
+
+static
+void nfs_readdir_free_large_page(void *ptr, struct page **pages,
+ unsigned int npages)
+{
+ vm_unmap_ram(ptr, npages);
+ nfs_readdir_free_pagearray(pages, npages);
+}
+
+/*
+ * nfs_readdir_large_page will allocate pages that must be freed with a call
+ * to nfs_readdir_free_large_page
+ */
+static
+void *nfs_readdir_large_page(struct page **pages, unsigned int npages)
+{
+ void *ptr;
+ unsigned int i;
+
+ for (i = 0; i < npages; i++) {
+ struct page *page = alloc_page(GFP_KERNEL);
+ if (page == NULL)
+ goto out_freepages;
+ pages[i] = page;
+ }
+
+ ptr = vm_map_ram(pages, NFS_MAX_READDIR_PAGES, 0, PAGE_KERNEL);
+ if (!IS_ERR_OR_NULL(ptr))
+ return ptr;
+out_freepages:
+ nfs_readdir_free_pagearray(pages, i);
+ return NULL;
}
static
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
{
- struct page *xdr_page;
+ struct page *pages[NFS_MAX_READDIR_PAGES];
+ void *pages_ptr = NULL;
struct nfs_entry entry;
struct file *file = desc->file;
struct nfs_cache_array *array;
@@ -470,17 +512,17 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
memset(array, 0, sizeof(struct nfs_cache_array));
array->eof_index = -1;
- xdr_page = alloc_page(GFP_KERNEL);
- if (!xdr_page)
+ pages_ptr = nfs_readdir_large_page(pages, ARRAY_SIZE(pages));
+ if (!pages_ptr)
goto out_release_array;
do {
- status = nfs_readdir_xdr_filler(xdr_page, desc, &entry, file, inode);
+ status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
if (status < 0)
break;
- nfs_readdir_page_filler(desc, &entry, xdr_page, page);
+ nfs_readdir_page_filler(desc, &entry, pages_ptr, page);
} while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);
- put_page(xdr_page);
+ nfs_readdir_free_large_page(pages_ptr, pages, ARRAY_SIZE(pages));
out_release_array:
nfs_readdir_release_array(page);
out:
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index c961bc9..f64382c 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -63,6 +63,12 @@ struct nfs_clone_mount {
#define NFS_UNSPEC_PORT (-1)
/*
+ * Maximum number of pages that readdir can use for creating
+ * a vmapped array of pages.
+ */
+#define NFS_MAX_READDIR_PAGES 8
+
+/*
* In-kernel mount arguments
*/
struct nfs_parsed_mount_data {
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index fabb4f2..033ed04 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -611,7 +611,7 @@ out:
*/
static int
nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
- u64 cookie, struct page *page, unsigned int count, int plus)
+ u64 cookie, struct page **pages, unsigned int count, int plus)
{
struct inode *dir = dentry->d_inode;
__be32 *verf = NFS_COOKIEVERF(dir);
@@ -621,7 +621,7 @@ nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
.verf = {verf[0], verf[1]},
.plus = plus,
.count = count,
- .pages = &page
+ .pages = pages
};
struct nfs3_readdirres res = {
.verf = verf,
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 089da5b..479f422 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2896,12 +2896,12 @@ static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
}
static int _nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
- u64 cookie, struct page *page, unsigned int count, int plus)
+ u64 cookie, struct page **pages, unsigned int count, int plus)
{
struct inode *dir = dentry->d_inode;
struct nfs4_readdir_arg args = {
.fh = NFS_FH(dir),
- .pages = &page,
+ .pages = pages,
.pgbase = 0,
.count = count,
.bitmask = NFS_SERVER(dentry->d_inode)->attr_bitmask,
@@ -2932,14 +2932,14 @@ static int _nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
}
static int nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
- u64 cookie, struct page *page, unsigned int count, int plus)
+ u64 cookie, struct page **pages, unsigned int count, int plus)
{
struct nfs4_exception exception = { };
int err;
do {
err = nfs4_handle_exception(NFS_SERVER(dentry->d_inode),
_nfs4_proc_readdir(dentry, cred, cookie,
- page, count, plus),
+ pages, count, plus),
&exception);
} while (exception.retry);
return err;
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 08ef912..f2e2f97 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4225,7 +4225,7 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
pglen = recvd;
xdr_read_pages(xdr, pglen);
- BUG_ON(pglen + readdir->pgbase > PAGE_CACHE_SIZE);
+ BUG_ON(pglen + readdir->pgbase > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES);
kaddr = p = kmap_atomic(page, KM_USER0);
end = p + ((pglen + readdir->pgbase) >> 2);
entry = p;
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 611bec2..3f1c181 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -519,14 +519,14 @@ nfs_proc_rmdir(struct inode *dir, struct qstr *name)
*/
static int
nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
- u64 cookie, struct page *page, unsigned int count, int plus)
+ u64 cookie, struct page **pages, unsigned int count, int plus)
{
struct inode *dir = dentry->d_inode;
struct nfs_readdirargs arg = {
.fh = NFS_FH(dir),
.cookie = cookie,
.count = count,
- .pages = &page,
+ .pages = pages,
};
struct rpc_message msg = {
.rpc_proc = &nfs_procedures[NFSPROC_READDIR],
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index fc46192..7d8cafa 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1044,7 +1044,7 @@ struct nfs_rpc_ops {
int (*mkdir) (struct inode *, struct dentry *, struct iattr *);
int (*rmdir) (struct inode *, struct qstr *);
int (*readdir) (struct dentry *, struct rpc_cred *,
- u64, struct page *, unsigned int, int);
+ u64, struct page **, unsigned int, int);
int (*mknod) (struct inode *, struct dentry *, struct iattr *,
dev_t);
int (*statfs) (struct nfs_server *, struct nfs_fh *,
--
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