Messages in this thread Patch in this message | | | From | Stephen Brennan <> | Subject | [PATCH 4/4] dcache: stop walking siblings if remaining dentries all negative | Date | Mon, 13 Dec 2021 16:53:37 -0800 |
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From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
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().
Co-authored-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Co-authored-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> --- fs/dcache.c | 9 +++++++++ fs/libfs.c | 3 +++ 2 files changed, 12 insertions(+)
diff --git a/fs/dcache.c b/fs/dcache.c index 9083436f5dcb..85f33563936b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1505,6 +1505,8 @@ 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)) { @@ -1751,6 +1753,10 @@ 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; @@ -3231,6 +3237,9 @@ 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
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