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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0189-fs-dcache-use-swait_queue-instead-of-waitqueue.patch | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/debian/patches-rt/0189-fs-dcache-use-swait_queue-instead-of-waitqueue.patch b/debian/patches-rt/0189-fs-dcache-use-swait_queue-instead-of-waitqueue.patch new file mode 100644 index 000000000..70a3b56d9 --- /dev/null +++ b/debian/patches-rt/0189-fs-dcache-use-swait_queue-instead-of-waitqueue.patch @@ -0,0 +1,241 @@ +From c6039e4946aa32ae6b790148a5a7357380e4a998 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 189/347] fs/dcache: use swait_queue instead of waitqueue +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +__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> +--- + fs/cifs/readdir.c | 2 +- + fs/dcache.c | 27 +++++++++++++++------------ + fs/fuse/dir.c | 2 +- + fs/namei.c | 4 ++-- + fs/nfs/dir.c | 4 ++-- + fs/nfs/unlink.c | 4 ++-- + fs/proc/base.c | 2 +- + fs/proc/proc_sysctl.c | 2 +- + include/linux/dcache.h | 4 ++-- + include/linux/nfs_xdr.h | 2 +- + kernel/sched/swait.c | 1 + + 11 files changed, 29 insertions(+), 25 deletions(-) + +diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c +index 3925a7bfc74d..33f7723fb83e 100644 +--- a/fs/cifs/readdir.c ++++ b/fs/cifs/readdir.c +@@ -80,7 +80,7 @@ cifs_prime_dcache(struct dentry *parent, struct qstr *name, + 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); + +diff --git a/fs/dcache.c b/fs/dcache.c +index 1ae163d54925..6e1c0b4c04f4 100644 +--- a/fs/dcache.c ++++ b/fs/dcache.c +@@ -2423,21 +2423,24 @@ static inline void end_dir_add(struct inode *dir, unsigned n) + + 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); +@@ -2552,7 +2555,7 @@ void __d_lookup_done(struct dentry *dentry) + 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); +diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c +index 6098e0c7f87b..9ce28840684a 100644 +--- a/fs/fuse/dir.c ++++ b/fs/fuse/dir.c +@@ -1234,7 +1234,7 @@ static int fuse_direntplus_link(struct file *file, + 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) { + /* +diff --git a/fs/namei.c b/fs/namei.c +index 327844fedf3d..5114c8111807 100644 +--- a/fs/namei.c ++++ b/fs/namei.c +@@ -1646,7 +1646,7 @@ static struct dentry *__lookup_slow(const struct qstr *name, + { + 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))) +@@ -3136,7 +3136,7 @@ static int lookup_open(struct nameidata *nd, struct path *path, + 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 -ENOENT; +diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c +index 4999bd148491..d8376dae3f7d 100644 +--- a/fs/nfs/dir.c ++++ b/fs/nfs/dir.c +@@ -457,7 +457,7 @@ static + void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) + { + 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 *dir = d_inode(parent); +@@ -1519,7 +1519,7 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry, + 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 }; +diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c +index ce9100b5604d..839bfa76f41e 100644 +--- a/fs/nfs/unlink.c ++++ b/fs/nfs/unlink.c +@@ -13,7 +13,7 @@ + #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> + +@@ -206,7 +206,7 @@ nfs_async_unlink(struct dentry *dentry, const struct qstr *name) + goto out_free_name; + } + 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); +diff --git a/fs/proc/base.c b/fs/proc/base.c +index e3f10c110b74..accc230079bb 100644 +--- a/fs/proc/base.c ++++ b/fs/proc/base.c +@@ -1889,7 +1889,7 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx, + + 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; +diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c +index c95f32b83a94..75f500cb7e74 100644 +--- a/fs/proc/proc_sysctl.c ++++ b/fs/proc/proc_sysctl.c +@@ -681,7 +681,7 @@ static bool proc_sys_fill_cache(struct file *file, + + 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; +diff --git a/include/linux/dcache.h b/include/linux/dcache.h +index 02b1b40fea5b..50cbde278301 100644 +--- a/include/linux/dcache.h ++++ b/include/linux/dcache.h +@@ -105,7 +105,7 @@ 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 */ +@@ -236,7 +236,7 @@ extern struct dentry * d_alloc(struct dentry *, const struct qstr *); + extern struct dentry * d_alloc_anon(struct super_block *); + extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *); + 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 *); +diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h +index cab24a127feb..73b0d19ef0d9 100644 +--- a/include/linux/nfs_xdr.h ++++ b/include/linux/nfs_xdr.h +@@ -1549,7 +1549,7 @@ struct nfs_unlinkdata { + struct nfs_removeargs args; + struct nfs_removeres res; + struct dentry *dentry; +- wait_queue_head_t wq; ++ struct swait_queue_head wq; + struct rpc_cred *cred; + struct nfs_fattr dir_attr; + long timeout; +diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c +index c7cb30cdd1b7..119a56d7f739 100644 +--- a/kernel/sched/swait.c ++++ b/kernel/sched/swait.c +@@ -70,6 +70,7 @@ void swake_up_all(struct swait_queue_head *q) + 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)) { +-- +2.36.1 + |