From 1ba4def609af040762de59edc5d71b48651e71ad Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Wed, 14 Sep 2016 14:35:49 +0200 Subject: [PATCH 101/166] fs/dcache: use swait_queue instead of waitqueue __d_lookup_done() invokes wake_up_all() while holding a hlist_bl_lock() which disables preemption. As a workaround convert it to swait. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- fs/afs/dir_silly.c | 2 +- fs/cifs/readdir.c | 2 +- fs/dcache.c | 27 +++++++++++++++------------ fs/fuse/readdir.c | 2 +- fs/namei.c | 4 ++-- fs/nfs/dir.c | 4 ++-- fs/nfs/unlink.c | 4 ++-- fs/proc/base.c | 3 ++- fs/proc/proc_sysctl.c | 2 +- include/linux/dcache.h | 4 ++-- include/linux/nfs_xdr.h | 2 +- kernel/sched/swait.c | 1 + 12 files changed, 31 insertions(+), 26 deletions(-) Index: linux-5.15.32-rt39/fs/afs/dir_silly.c =================================================================== @ linux-5.15.32-rt39/fs/afs/dir_silly.c:242 @ int afs_silly_iput(struct dentry *dentry struct dentry *alias; int ret; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); _enter("%p{%pd},%llx", dentry, dentry, vnode->fid.vnode); Index: linux-5.15.32-rt39/fs/cifs/readdir.c =================================================================== --- linux-5.15.32-rt39.orig/fs/cifs/readdir.c +++ linux-5.15.32-rt39/fs/cifs/readdir.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:72 @ cifs_prime_dcache(struct dentry *parent, struct inode *inode; struct super_block *sb = parent->d_sb; struct cifs_sb_info *cifs_sb = CIFS_SB(sb); - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); cifs_dbg(FYI, "%s: for %s\n", __func__, name->name); Index: linux-5.15.32-rt39/fs/dcache.c =================================================================== --- linux-5.15.32-rt39.orig/fs/dcache.c +++ linux-5.15.32-rt39/fs/dcache.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:2556 @ static inline void end_dir_add(struct in static void d_wait_lookup(struct dentry *dentry) { - if (d_in_lookup(dentry)) { - DECLARE_WAITQUEUE(wait, current); - add_wait_queue(dentry->d_wait, &wait); - do { - set_current_state(TASK_UNINTERRUPTIBLE); - spin_unlock(&dentry->d_lock); - schedule(); - spin_lock(&dentry->d_lock); - } while (d_in_lookup(dentry)); - } + struct swait_queue __wait; + + if (!d_in_lookup(dentry)) + return; + + INIT_LIST_HEAD(&__wait.task_list); + do { + prepare_to_swait_exclusive(dentry->d_wait, &__wait, TASK_UNINTERRUPTIBLE); + spin_unlock(&dentry->d_lock); + schedule(); + spin_lock(&dentry->d_lock); + } while (d_in_lookup(dentry)); + finish_swait(dentry->d_wait, &__wait); } struct dentry *d_alloc_parallel(struct dentry *parent, const struct qstr *name, - wait_queue_head_t *wq) + struct swait_queue_head *wq) { unsigned int hash = name->hash; struct hlist_bl_head *b = in_lookup_hash(parent, hash); @ linux-5.15.32-rt39/fs/afs/dir_silly.c:2688 @ void __d_lookup_done(struct dentry *dent hlist_bl_lock(b); dentry->d_flags &= ~DCACHE_PAR_LOOKUP; __hlist_bl_del(&dentry->d_u.d_in_lookup_hash); - wake_up_all(dentry->d_wait); + swake_up_all(dentry->d_wait); dentry->d_wait = NULL; hlist_bl_unlock(b); INIT_HLIST_NODE(&dentry->d_u.d_alias); Index: linux-5.15.32-rt39/fs/fuse/readdir.c =================================================================== --- linux-5.15.32-rt39.orig/fs/fuse/readdir.c +++ linux-5.15.32-rt39/fs/fuse/readdir.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:161 @ static int fuse_direntplus_link(struct f struct inode *dir = d_inode(parent); struct fuse_conn *fc; struct inode *inode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); if (!o->nodeid) { /* Index: linux-5.15.32-rt39/fs/namei.c =================================================================== --- linux-5.15.32-rt39.orig/fs/namei.c +++ linux-5.15.32-rt39/fs/namei.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:1636 @ static struct dentry *__lookup_slow(cons { struct dentry *dentry, *old; struct inode *inode = dir->d_inode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); /* Don't go there if it's already dead */ if (unlikely(IS_DEADDIR(inode))) @ linux-5.15.32-rt39/fs/afs/dir_silly.c:3247 @ static struct dentry *lookup_open(struct struct dentry *dentry; int error, create_error = 0; umode_t mode = op->mode; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); if (unlikely(IS_DEADDIR(dir_inode))) return ERR_PTR(-ENOENT); Index: linux-5.15.32-rt39/fs/nfs/dir.c =================================================================== --- linux-5.15.32-rt39.orig/fs/nfs/dir.c +++ linux-5.15.32-rt39/fs/nfs/dir.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:639 @ void nfs_prime_dcache(struct dentry *par unsigned long dir_verifier) { struct qstr filename = QSTR_INIT(entry->name, entry->len); - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); struct dentry *dentry; struct dentry *alias; struct inode *inode; @ linux-5.15.32-rt39/fs/afs/dir_silly.c:1870 @ int nfs_atomic_open(struct inode *dir, s struct file *file, unsigned open_flags, umode_t mode) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); struct nfs_open_context *ctx; struct dentry *res; struct iattr attr = { .ia_valid = ATTR_OPEN }; Index: linux-5.15.32-rt39/fs/nfs/unlink.c =================================================================== --- linux-5.15.32-rt39.orig/fs/nfs/unlink.c +++ linux-5.15.32-rt39/fs/nfs/unlink.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:16 @ #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> #include <linux/sched.h> -#include <linux/wait.h> +#include <linux/swait.h> #include <linux/namei.h> #include <linux/fsnotify.h> @ linux-5.15.32-rt39/fs/afs/dir_silly.c:187 @ nfs_async_unlink(struct dentry *dentry, data->cred = get_current_cred(); data->res.dir_attr = &data->dir_attr; - init_waitqueue_head(&data->wq); + init_swait_queue_head(&data->wq); status = -EBUSY; spin_lock(&dentry->d_lock); Index: linux-5.15.32-rt39/fs/proc/base.c =================================================================== --- linux-5.15.32-rt39.orig/fs/proc/base.c +++ linux-5.15.32-rt39/fs/proc/base.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:99 @ #include <linux/posix-timers.h> #include <linux/time_namespace.h> #include <linux/resctrl.h> +#include <linux/swait.h> #include <linux/cn_proc.h> #include <trace/events/oom.h> #include "internal.h" @ linux-5.15.32-rt39/fs/afs/dir_silly.c:2047 @ bool proc_fill_cache(struct file *file, child = d_hash_and_lookup(dir, &qname); if (!child) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); child = d_alloc_parallel(dir, &qname, &wq); if (IS_ERR(child)) goto end_instantiate; Index: linux-5.15.32-rt39/fs/proc/proc_sysctl.c =================================================================== --- linux-5.15.32-rt39.orig/fs/proc/proc_sysctl.c +++ linux-5.15.32-rt39/fs/proc/proc_sysctl.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:681 @ static bool proc_sys_fill_cache(struct f child = d_lookup(dir, &qname); if (!child) { - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + DECLARE_SWAIT_QUEUE_HEAD_ONSTACK(wq); child = d_alloc_parallel(dir, &qname, &wq); if (IS_ERR(child)) return false; Index: linux-5.15.32-rt39/include/linux/dcache.h =================================================================== --- linux-5.15.32-rt39.orig/include/linux/dcache.h +++ linux-5.15.32-rt39/include/linux/dcache.h @ linux-5.15.32-rt39/fs/afs/dir_silly.c:111 @ struct dentry { union { struct list_head d_lru; /* LRU list */ - wait_queue_head_t *d_wait; /* in-lookup ones only */ + struct swait_queue_head *d_wait; /* in-lookup ones only */ }; struct list_head d_child; /* child of parent list */ struct list_head d_subdirs; /* our children */ @ linux-5.15.32-rt39/fs/afs/dir_silly.c:243 @ extern void d_set_d_op(struct dentry *de extern struct dentry * d_alloc(struct dentry *, const struct qstr *); extern struct dentry * d_alloc_anon(struct super_block *); extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *, - wait_queue_head_t *); + struct swait_queue_head *); extern struct dentry * d_splice_alias(struct inode *, struct dentry *); extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *); extern struct dentry * d_exact_alias(struct dentry *, struct inode *); Index: linux-5.15.32-rt39/include/linux/nfs_xdr.h =================================================================== --- linux-5.15.32-rt39.orig/include/linux/nfs_xdr.h +++ linux-5.15.32-rt39/include/linux/nfs_xdr.h @ linux-5.15.32-rt39/fs/afs/dir_silly.c:1695 @ struct nfs_unlinkdata { struct nfs_removeargs args; struct nfs_removeres res; struct dentry *dentry; - wait_queue_head_t wq; + struct swait_queue_head wq; const struct cred *cred; struct nfs_fattr dir_attr; long timeout; Index: linux-5.15.32-rt39/kernel/sched/swait.c =================================================================== --- linux-5.15.32-rt39.orig/kernel/sched/swait.c +++ linux-5.15.32-rt39/kernel/sched/swait.c @ linux-5.15.32-rt39/fs/afs/dir_silly.c:67 @ void swake_up_all(struct swait_queue_hea struct swait_queue *curr; LIST_HEAD(tmp); + WARN_ON(irqs_disabled()); raw_spin_lock_irq(&q->lock); list_splice_init(&q->task_list, &tmp); while (!list_empty(&tmp)) {