[PATCH 4/4] Optimize NFS open() calls by means of 'intents'...

Trond Myklebust (trond.myklebust@fys.uio.no)
Fri, 23 May 2003 14:46:12 +0200


Do close-to-open data revalidation inside the i_op->lookup() and
d_op->d_revalidate() routines by using intents to discover whether or
not this is an open().

Implement open(O_EXCL) by means of the i_op->create() intents.

Cheers,
Trond

diff -u --recursive --new-file linux-2.5.69-03-creat/fs/nfs/dir.c linux-2.5.69-04-cto_excl/fs/nfs/dir.c
--- linux-2.5.69-03-creat/fs/nfs/dir.c 2003-05-23 00:13:37.000000000 +0200
+++ linux-2.5.69-04-cto_excl/fs/nfs/dir.c 2003-05-23 01:17:20.000000000 +0200
@@ -31,6 +31,7 @@
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include <linux/namei.h>
+#include <linux/open.h>

#define NFS_PARANOIA 1
/* #define NFS_DEBUG_VERBOSE 1 */
@@ -78,16 +79,11 @@
static int
nfs_opendir(struct inode *inode, struct file *filp)
{
- struct nfs_server *server = NFS_SERVER(inode);
- int res = 0;
+ int res;

lock_kernel();
- /* Do cto revalidation */
- if (!(server->flags & NFS_MOUNT_NOCTO))
- res = __nfs_revalidate_inode(server, inode);
/* Call generic open code in order to cache credentials */
- if (!res)
- res = nfs_open(inode, filp);
+ res = nfs_open(inode, filp);
unlock_kernel();
return res;
}
@@ -466,11 +462,17 @@
* and may need to be looked up again.
*/
static inline
-int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
+int nfs_check_verifier(struct inode *dir, struct dentry *dentry, struct vfsintent *intent)
{
+ struct nfs_server *server = NFS_SERVER(dir);
if (IS_ROOT(dentry))
return 1;
- if (nfs_revalidate_inode(NFS_SERVER(dir), dir))
+ /* If we're doing an open(), then observe the 'cto' flag */
+ if (intent && intent->type == OPEN_INTENT
+ && !(server->flags & NFS_MOUNT_NOCTO)) {
+ if (__nfs_revalidate_inode(server, dir))
+ return 0;
+ } else if (nfs_revalidate_inode(server, dir))
return 0;
return time_after(dentry->d_time, NFS_MTIME_UPDATE(dir));
}
@@ -485,9 +487,15 @@
}

static inline
-int nfs_lookup_verify_inode(struct inode *inode)
+int nfs_lookup_verify_inode(struct inode *inode, struct vfsintent *intent)
{
- return nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ struct nfs_server *server = NFS_SERVER(inode);
+
+ /* If we're doing an open(), then observe the 'cto' flag */
+ if (intent && intent->type == OPEN_INTENT
+ && !(server->flags & NFS_MOUNT_NOCTO))
+ return __nfs_revalidate_inode(server, inode);
+ return nfs_revalidate_inode(server, inode);
}

/*
@@ -497,9 +505,11 @@
* If parent mtime has changed, we revalidate, else we wait for a
* period corresponding to the parent's attribute cache timeout value.
*/
-static inline int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry)
+static inline
+int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
+ struct vfsintent *intent)
{
- if (!nfs_check_verifier(dir, dentry))
+ if (!nfs_check_verifier(dir, dentry, intent))
return 1;
return time_after(jiffies, dentry->d_time + NFS_ATTRTIMEO(dir));
}
@@ -530,7 +540,7 @@
inode = dentry->d_inode;

if (!inode) {
- if (nfs_neg_need_reval(dir, dentry))
+ if (nfs_neg_need_reval(dir, dentry, intent))
goto out_bad;
goto out_valid;
}
@@ -542,8 +552,8 @@
}

/* Force a full look up iff the parent directory has changed */
- if (nfs_check_verifier(dir, dentry)) {
- if (nfs_lookup_verify_inode(inode))
+ if (nfs_check_verifier(dir, dentry, intent)) {
+ if (nfs_lookup_verify_inode(inode, intent))
goto out_bad;
goto out_valid;
}
@@ -552,7 +562,7 @@
if (!error) {
if (memcmp(NFS_FH(inode), &fhandle, sizeof(struct nfs_fh))!= 0)
goto out_bad;
- if (nfs_lookup_verify_inode(inode))
+ if (nfs_lookup_verify_inode(inode, intent))
goto out_bad;
goto out_valid_renew;
}
@@ -632,6 +642,7 @@

static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct vfsintent *intent)
{
+ struct nfs_server *server = NFS_SERVER(dir);
struct inode *inode = NULL;
int error;
struct nfs_fh fhandle;
@@ -641,23 +652,29 @@
dentry->d_parent->d_name.name, dentry->d_name.name);

error = -ENAMETOOLONG;
- if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+ if (dentry->d_name.len > server->namelen)
goto out;

error = -ENOMEM;
dentry->d_op = &nfs_dentry_operations;

lock_kernel();
- error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
- if (!error) {
- error = -EACCES;
- inode = nfs_fhget(dentry, &fhandle, &fattr);
- if (inode) {
- d_add(dentry, inode);
- nfs_renew_times(dentry);
- error = 0;
+ /* If we're not doing an open(), or we are 'nocto', then
+ * we may use the readdirplus cache
+ */
+ if (!intent || intent->type != OPEN_INTENT ||
+ (server->flags & NFS_MOUNT_NOCTO)) {
+ error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
+ if (!error) {
+ error = -EACCES;
+ inode = nfs_fhget(dentry, &fhandle, &fattr);
+ if (inode) {
+ d_add(dentry, inode);
+ nfs_renew_times(dentry);
+ error = 0;
+ }
+ goto out_unlock;
}
- goto out_unlock;
}

error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
@@ -793,6 +810,7 @@
struct iattr attr;
struct nfs_fattr fattr;
struct nfs_fh fhandle;
+ int flags = 0;
int error;

dfprintk(VFS, "NFS: create(%s/%ld, %s\n", dir->i_sb->s_id,
@@ -801,16 +819,15 @@
attr.ia_mode = mode;
attr.ia_valid = ATTR_MODE;

- /*
- * The 0 argument passed into the create function should one day
- * contain the O_EXCL flag if requested. This allows NFSv3 to
- * select the appropriate create strategy. Currently open_namei
- * does not pass the create flags.
- */
+ if (intent && intent->type == OPEN_INTENT) {
+ struct opendata *opendata;
+ opendata = container_of(intent, struct opendata, intent);
+ flags = opendata->flag;
+ }
lock_kernel();
nfs_zap_caches(dir);
error = NFS_PROTO(dir)->create(dir, &dentry->d_name,
- &attr, 0, &fhandle, &fattr);
+ &attr, flags, &fhandle, &fattr);
if (!error)
error = nfs_instantiate(dentry, &fhandle, &fattr);
else
diff -u --recursive --new-file linux-2.5.69-03-creat/fs/nfs/file.c linux-2.5.69-04-cto_excl/fs/nfs/file.c
--- linux-2.5.69-03-creat/fs/nfs/file.c 2003-05-07 12:34:41.000000000 +0200
+++ linux-2.5.69-04-cto_excl/fs/nfs/file.c 2003-05-23 00:50:27.000000000 +0200
@@ -82,9 +82,6 @@
/* Do NFSv4 open() call */
if ((open = server->rpc_ops->file_open) != NULL)
res = open(inode, filp);
- /* Do cto revalidation */
- else if (!(server->flags & NFS_MOUNT_NOCTO))
- res = __nfs_revalidate_inode(server, inode);
/* Call generic open code in order to cache credentials */
if (!res)
res = nfs_open(inode, filp);
-
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