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NFS: Don't ask for readdirplus unless it can help nfs_getattr()

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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 <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust
2022-02-17 15:46:23 -05:00
parent 230bc98f7a
commit ad1e109a41
1 changed files with 25 additions and 20 deletions
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35
fs/nfs/inode.c
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@@ -780,27 +780,33 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
} }
EXPORT_SYMBOL_GPL(nfs_setattr_update_inode); EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
/*
* 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)
{
return nfs_server_capable(inode, NFS_CAP_READDIRPLUS) &&
!nfs_have_writebacks(inode) && NFS_MAXATTRTIMEO(inode) > 5 * HZ;
}
static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry) static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
{ {
struct dentry *parent; if (!IS_ROOT(dentry)) {
struct dentry *parent = dget_parent(dentry);
if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
return;
parent = dget_parent(dentry);
nfs_readdir_record_entry_cache_miss(d_inode(parent)); nfs_readdir_record_entry_cache_miss(d_inode(parent));
dput(parent); dput(parent);
} }
}
static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry) static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
{ {
struct dentry *parent; if (!IS_ROOT(dentry)) {
struct dentry *parent = dget_parent(dentry);
if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
return;
parent = dget_parent(dentry);
nfs_readdir_record_entry_cache_hit(d_inode(parent)); nfs_readdir_record_entry_cache_hit(d_inode(parent));
dput(parent); dput(parent);
} }
}
static u32 nfs_get_valid_attrmask(struct inode *inode) static u32 nfs_get_valid_attrmask(struct inode *inode)
{ {
@@ -835,6 +841,7 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
int err = 0; int err = 0;
bool force_sync = query_flags & AT_STATX_FORCE_SYNC; bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
bool do_update = false; bool do_update = false;
bool readdirplus_enabled = nfs_getattr_readdirplus_enable(inode);
trace_nfs_getattr_enter(inode); trace_nfs_getattr_enter(inode);
@@ -843,6 +850,7 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
STATX_INO | STATX_SIZE | STATX_BLOCKS; STATX_INO | STATX_SIZE | STATX_BLOCKS;
if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) { if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
if (readdirplus_enabled)
nfs_readdirplus_parent_cache_hit(path->dentry); nfs_readdirplus_parent_cache_hit(path->dentry);
goto out_no_revalidate; goto out_no_revalidate;
} }
@@ -893,15 +901,12 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
do_update |= cache_validity & NFS_INO_INVALID_BLOCKS; do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
if (do_update) { if (do_update) {
/* Update the attribute cache */ if (readdirplus_enabled)
if (!(server->flags & NFS_MOUNT_NOAC))
nfs_readdirplus_parent_cache_miss(path->dentry); nfs_readdirplus_parent_cache_miss(path->dentry);
else
nfs_readdirplus_parent_cache_hit(path->dentry);
err = __nfs_revalidate_inode(server, inode); err = __nfs_revalidate_inode(server, inode);
if (err) if (err)
goto out; goto out;
} else } else if (readdirplus_enabled)
nfs_readdirplus_parent_cache_hit(path->dentry); nfs_readdirplus_parent_cache_hit(path->dentry);
out_no_revalidate: out_no_revalidate:
/* Only return attributes that were revalidated. */ /* Only return attributes that were revalidated. */