From: Trond Myklebust <[email protected]>
If attribute caching is turned off, then use of readdirplus is not going
to help stat() performance.
Readdirplus also doesn't help if a file is being written to, since we
will have to flush those writes in order to sync the mtime/ctime.
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/inode.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index bbf4357ff727..10d17cfb8639 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -780,24 +780,26 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
}
EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
-static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
+/*
+ * Don't request help from readdirplus if the file is being written to,
+ * or if attribute caching is turned off
+ */
+static bool nfs_getattr_readdirplus_enable(const struct inode *inode)
{
- struct dentry *parent;
+ return nfs_server_capable(inode, NFS_CAP_READDIRPLUS) &&
+ !nfs_have_writebacks(inode) && NFS_MAXATTRTIMEO(inode) > 5 * HZ;
+}
- if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
- return;
- parent = dget_parent(dentry);
+static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
+{
+ struct dentry *parent = dget_parent(dentry);
nfs_readdir_record_entry_cache_miss(d_inode(parent));
dput(parent);
}
static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
{
- struct dentry *parent;
-
- if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
- return;
- parent = dget_parent(dentry);
+ struct dentry *parent = dget_parent(dentry);
nfs_readdir_record_entry_cache_hit(d_inode(parent));
dput(parent);
}
@@ -835,6 +837,7 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
int err = 0;
bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
bool do_update = false;
+ bool readdirplus_enabled = nfs_getattr_readdirplus_enable(inode);
trace_nfs_getattr_enter(inode);
@@ -843,7 +846,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
STATX_INO | STATX_SIZE | STATX_BLOCKS;
if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
- nfs_readdirplus_parent_cache_hit(path->dentry);
+ if (readdirplus_enabled)
+ nfs_readdirplus_parent_cache_hit(path->dentry);
goto out_no_revalidate;
}
@@ -893,15 +897,12 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
if (do_update) {
- /* Update the attribute cache */
- if (!(server->flags & NFS_MOUNT_NOAC))
+ if (readdirplus_enabled)
nfs_readdirplus_parent_cache_miss(path->dentry);
- else
- nfs_readdirplus_parent_cache_hit(path->dentry);
err = __nfs_revalidate_inode(server, inode);
if (err)
goto out;
- } else
+ } else if (readdirplus_enabled)
nfs_readdirplus_parent_cache_hit(path->dentry);
out_no_revalidate:
/* Only return attributes that were revalidated. */
--
2.35.1