From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Most walkers are interested only in positive dentries.
Changes in simple_* libfs helpers are mostly cosmetic: it shouldn't cache
negative dentries unless uses d_delete other than always_delete_dentry().
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Signed-off-by: Gautham Ananthakrishna <gautham.ananthakrishna@xxxxxxxxxx>
Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx>
---
fs/dcache.c | 9 +++++++++
fs/libfs.c | 3 +++
2 files changed, 12 insertions(+)
diff --git a/fs/dcache.c b/fs/dcache.c
index 8809643a4d5b..e98079ed86be 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1530,6 +1530,8 @@ static enum d_walk_ret path_check_mount(void *data, struct dentry *dentry)
struct check_mount *info = data;
struct path path = { .mnt = info->mnt, .dentry = dentry };
+ if (d_is_tail_negative(dentry))
+ return D_WALK_SKIP_SIBLINGS;
if (likely(!d_mountpoint(dentry)))
return D_WALK_CONTINUE;
if (__path_is_mountpoint(&path)) {
@@ -1776,6 +1778,10 @@ void shrink_dcache_for_umount(struct super_block *sb)
static enum d_walk_ret find_submount(void *_data, struct dentry *dentry)
{
struct dentry **victim = _data;
+
+ if (d_is_tail_negative(dentry))
+ return D_WALK_SKIP_SIBLINGS;
+
if (d_mountpoint(dentry)) {
__dget_dlock(dentry);
*victim = dentry;
@@ -3256,6 +3262,9 @@ static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry)
{
struct dentry *root = data;
if (dentry != root) {
+ if (d_is_tail_negative(dentry))
+ return D_WALK_SKIP_SIBLINGS;
+
if (d_unhashed(dentry) || !dentry->d_inode)
return D_WALK_SKIP;
diff --git a/fs/libfs.c b/fs/libfs.c
index ba7438ab9371..13cb44cf158e 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -411,6 +411,9 @@ int simple_empty(struct dentry *dentry)
spin_lock(&dentry->d_lock);
list_for_each_entry(child, &dentry->d_subdirs, d_child) {
+ if (d_is_tail_negative(child))
+ break;
+
spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(child)) {
spin_unlock(&child->d_lock);
--
2.30.2
