diff options
| -rw-r--r-- | fs/dcache.c | 122 |
1 files changed, 43 insertions, 79 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 2acfc69878f5..1d40d8b3ad34 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -580,6 +580,7 @@ static void __dentry_kill(struct dentry *dentry) spin_unlock(&dentry->d_lock); if (likely(can_free)) dentry_free(dentry); + cond_resched(); } static struct dentry *__lock_parent(struct dentry *dentry) @@ -827,30 +828,24 @@ static inline bool fast_dput(struct dentry *dentry) */ void dput(struct dentry *dentry) { - if (unlikely(!dentry)) - return; + while (dentry) { + might_sleep(); -repeat: - might_sleep(); + rcu_read_lock(); + if (likely(fast_dput(dentry))) { + rcu_read_unlock(); + return; + } - rcu_read_lock(); - if (likely(fast_dput(dentry))) { + /* Slow case: now with the dentry lock held */ rcu_read_unlock(); - return; - } - /* Slow case: now with the dentry lock held */ - rcu_read_unlock(); - - if (likely(retain_dentry(dentry))) { - spin_unlock(&dentry->d_lock); - return; - } + if (likely(retain_dentry(dentry))) { + spin_unlock(&dentry->d_lock); + return; + } - dentry = dentry_kill(dentry); - if (dentry) { - cond_resched(); - goto repeat; + dentry = dentry_kill(dentry); } } EXPORT_SYMBOL(dput); @@ -1052,8 +1047,6 @@ static void shrink_dentry_list(struct list_head *list) while (!list_empty(list)) { struct dentry *dentry, *parent; - cond_resched(); - dentry = list_entry(list->prev, struct dentry, d_lru); spin_lock(&dentry->d_lock); rcu_read_lock(); @@ -1230,13 +1223,11 @@ enum d_walk_ret { * @parent: start of walk * @data: data passed to @enter() and @finish() * @enter: callback when first entering the dentry - * @finish: callback when successfully finished the walk * - * The @enter() and @finish() callbacks are called with d_lock held. + * The @enter() callbacks are called with d_lock held. */ static void d_walk(struct dentry *parent, void *data, - enum d_walk_ret (*enter)(void *, struct dentry *), - void (*finish)(void *)) + enum d_walk_ret (*enter)(void *, struct dentry *)) { struct dentry *this_parent; struct list_head *next; @@ -1325,8 +1316,6 @@ ascend: if (need_seqretry(&rename_lock, seq)) goto rename_retry; rcu_read_unlock(); - if (finish) - finish(data); out_unlock: spin_unlock(&this_parent->d_lock); @@ -1375,7 +1364,7 @@ int path_has_submounts(const struct path *parent) struct check_mount data = { .mnt = parent->mnt, .mounted = 0 }; read_seqlock_excl(&mount_lock); - d_walk(parent->dentry, &data, path_check_mount, NULL); + d_walk(parent->dentry, &data, path_check_mount); read_sequnlock_excl(&mount_lock); return data.mounted; @@ -1483,11 +1472,16 @@ void shrink_dcache_parent(struct dentry *parent) data.start = parent; data.found = 0; - d_walk(parent, &data, select_collect, NULL); + d_walk(parent, &data, select_collect); + + if (!list_empty(&data.dispose)) { + shrink_dentry_list(&data.dispose); + continue; + } + + cond_resched(); if (!data.found) break; - - shrink_dentry_list(&data.dispose); } } EXPORT_SYMBOL(shrink_dcache_parent); @@ -1518,7 +1512,7 @@ static enum d_walk_ret umount_check(void *_data, struct dentry *dentry) static void do_one_tree(struct dentry *dentry) { shrink_dcache_parent(dentry); - d_walk(dentry, dentry, umount_check, NULL); + d_walk(dentry, dentry, umount_check); d_drop(dentry); dput(dentry); } @@ -1542,78 +1536,48 @@ void shrink_dcache_for_umount(struct super_block *sb) } } -struct detach_data { - struct select_data select; - struct dentry *mountpoint; -}; -static enum d_walk_ret detach_and_collect(void *_data, struct dentry *dentry) +static enum d_walk_ret find_submount(void *_data, struct dentry *dentry) { - struct detach_data *data = _data; - + struct dentry **victim = _data; if (d_mountpoint(dentry)) { __dget_dlock(dentry); - data->mountpoint = dentry; + *victim = dentry; return D_WALK_QUIT; } - - return select_collect(&data->select, dentry); -} - -static void check_and_drop(void *_data) -{ - struct detach_data *data = _data; - - if (!data->mountpoint && list_empty(&data->select.dispose)) - __d_drop(data->select.start); + return D_WALK_CONTINUE; } /** * d_invalidate - detach submounts, prune dcache, and drop * @dentry: dentry to invalidate (aka detach, prune and drop) - * - * no dcache lock. - * - * The final d_drop is done as an atomic operation relative to - * rename_lock ensuring there are no races with d_set_mounted. This - * ensures there are no unhashed dentries on the path to a mountpoint. */ void d_invalidate(struct dentry *dentry) { - /* - * If it's already been dropped, return OK. - */ + bool had_submounts = false; spin_lock(&dentry->d_lock); if (d_unhashed(dentry)) { spin_unlock(&dentry->d_lock); return; } + __d_drop(dentry); spin_unlock(&dentry->d_lock); /* Negative dentries can be dropped without further checks */ - if (!dentry->d_inode) { - d_drop(dentry); + if (!dentry->d_inode) return; - } + shrink_dcache_parent(dentry); for (;;) { - struct detach_data data; - - data.mountpoint = NULL; - INIT_LIST_HEAD(&data.select.dispose); - data.select.start = dentry; - data.select.found = 0; - - d_walk(dentry, &data, detach_and_collect, check_and_drop); - - if (!list_empty(&data.select.dispose)) - shrink_dentry_list(&data.select.dispose); - else if (!data.mountpoint) + struct dentry *victim = NULL; + d_walk(dentry, &victim, find_submount); + if (!victim) { + if (had_submounts) + shrink_dcache_parent(dentry); return; - - if (data.mountpoint) { - detach_mounts(data.mountpoint); - dput(data.mountpoint); } + had_submounts = true; + detach_mounts(victim); + dput(victim); } } EXPORT_SYMBOL(d_invalidate); @@ -3134,7 +3098,7 @@ static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry) void d_genocide(struct dentry *parent) { - d_walk(parent, parent, d_genocide_kill, NULL); + d_walk(parent, parent, d_genocide_kill); } EXPORT_SYMBOL(d_genocide); |