On Fri, Jan 31, 2020 at 1:51 PM Miklos Szeredi <mszeredi@xxxxxxxxxx> wrote: > > Allow completely skipping ->revalidate() on a per-dentry bases, in case the > underlying layers used for a dentry do not themselves have ->revalidate(). > > E.g. negative overlay dentry has no underlying layers, hence revalidate is > unnecessary. Or if lower layer is remote but overlay dentry is pure-upper, > then can skip revalidate. > > The following places need to update whether the dentry needs revalidate or > not: > > - fill-super (root dentry) > - lookup > - create > - fh_to_dentry > > Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx> > --- > fs/overlayfs/dir.c | 3 +++ > fs/overlayfs/export.c | 2 ++ > fs/overlayfs/namei.c | 3 +++ > fs/overlayfs/overlayfs.h | 3 ++- > fs/overlayfs/super.c | 23 +++++++---------------- > fs/overlayfs/util.c | 15 ++++++++++++--- > 6 files changed, 29 insertions(+), 20 deletions(-) > > diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c > index 8e57d5372b8f..b3471ef51440 100644 > --- a/fs/overlayfs/dir.c > +++ b/fs/overlayfs/dir.c > @@ -243,6 +243,9 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode, > > ovl_dir_modified(dentry->d_parent, false); > ovl_dentry_set_upper_alias(dentry); > + ovl_dentry_update_reval(dentry, newdentry, > + DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); > + > if (!hardlink) { > /* > * ovl_obtain_alias() can be called after ovl_create_real() > diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c > index 6f54d70cef27..a58b3d9b06b9 100644 > --- a/fs/overlayfs/export.c > +++ b/fs/overlayfs/export.c > @@ -324,6 +324,8 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb, > if (upper_alias) > ovl_dentry_set_upper_alias(dentry); > } > + ovl_dentry_update_reval(dentry, upper, > + DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); > > return d_instantiate_anon(dentry, inode); > > diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c > index a5b998a93a24..76e61cc27822 100644 > --- a/fs/overlayfs/namei.c > +++ b/fs/overlayfs/namei.c > @@ -1077,6 +1077,9 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, > goto out_free_oe; > } > > + ovl_dentry_update_reval(dentry, upperdentry, > + DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); > + > revert_creds(old_cred); > if (origin_path) { > dput(origin_path->dentry); > diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h > index 3623d28aa4fa..68124a4f8f9b 100644 > --- a/fs/overlayfs/overlayfs.h > +++ b/fs/overlayfs/overlayfs.h > @@ -229,7 +229,8 @@ struct dentry *ovl_indexdir(struct super_block *sb); > bool ovl_index_all(struct super_block *sb); > bool ovl_verify_lower(struct super_block *sb); > struct ovl_entry *ovl_alloc_entry(unsigned int numlower); > -bool ovl_dentry_remote(struct dentry *dentry); > +void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, > + unsigned int mask); > bool ovl_dentry_weird(struct dentry *dentry); > enum ovl_path_type ovl_path_type(struct dentry *dentry); > void ovl_path_upper(struct dentry *dentry, struct path *path); > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > index 7e294bf719ff..26d4153240a8 100644 > --- a/fs/overlayfs/super.c > +++ b/fs/overlayfs/super.c > @@ -158,11 +158,6 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) > static const struct dentry_operations ovl_dentry_operations = { > .d_release = ovl_dentry_release, > .d_real = ovl_d_real, > -}; > - > -static const struct dentry_operations ovl_reval_dentry_operations = { > - .d_release = ovl_dentry_release, > - .d_real = ovl_d_real, > .d_revalidate = ovl_dentry_revalidate, > .d_weak_revalidate = ovl_dentry_weak_revalidate, > }; > @@ -779,7 +774,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs, > } > > static int ovl_lower_dir(const char *name, struct path *path, > - struct ovl_fs *ofs, int *stack_depth, bool *remote) > + struct ovl_fs *ofs, int *stack_depth) > { > int fh_type; > int err; > @@ -794,9 +789,6 @@ static int ovl_lower_dir(const char *name, struct path *path, > > *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); > > - if (ovl_dentry_remote(path->dentry)) > - *remote = true; > - > /* > * The inodes index feature and NFS export need to encode and decode > * file handles, so they require that all layers support them. > @@ -1439,7 +1431,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, > char *lowertmp, *lower; > struct path *stack = NULL; > unsigned int stacklen, numlower = 0, i; > - bool remote = false; > struct ovl_entry *oe; > > err = -ENOMEM; > @@ -1471,7 +1462,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, > lower = lowertmp; > for (numlower = 0; numlower < stacklen; numlower++) { > err = ovl_lower_dir(lower, &stack[numlower], ofs, > - &sb->s_stack_depth, &remote); > + &sb->s_stack_depth); > if (err) > goto out_err; > > @@ -1499,11 +1490,6 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, > oe->lowerstack[i].layer = &ofs->layers[i+1]; > } > > - if (remote) > - sb->s_d_op = &ovl_reval_dentry_operations; > - else > - sb->s_d_op = &ovl_dentry_operations; > - > out: > for (i = 0; i < numlower; i++) > path_put(&stack[i]); > @@ -1597,6 +1583,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) > struct cred *cred; > int err; > > + sb->s_d_op = &ovl_dentry_operations; > + > err = -ENOMEM; > ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); > if (!ofs) > @@ -1724,6 +1712,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) > ovl_inode_init(d_inode(root_dentry), upperpath.dentry, > ovl_dentry_lower(root_dentry), NULL); > > + ovl_dentry_update_reval(root_dentry, upperpath.dentry, > + DCACHE_OP_WEAK_REVALIDATE); > + > sb->s_root = root_dentry; > > return 0; > diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c > index 67cd2866aaa2..3ad8fb291f7d 100644 > --- a/fs/overlayfs/util.c > +++ b/fs/overlayfs/util.c > @@ -90,10 +90,19 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower) > return oe; > } > > -bool ovl_dentry_remote(struct dentry *dentry) Removed too early. It still has users. Otherwise looks ok. Thanks, Amir.