From: Thomas Gleixner Replace the open coded seqlock with a real one, so RT can handle it. Signed-off-by: Thomas Gleixner Cc: stable-rt@vger.kernel.org Signed-off-by: Steven Rostedt --- fs/exec.c | 4 +- fs/fhandle.c | 4 +- fs/fs_struct.c | 46 +++++++++++++++++--------------------------- fs/namei.c | 14 ++++++------ include/linux/fs_struct.h | 16 ++++++-------- kernel/fork.c | 10 ++++---- 6 files changed, 41 insertions(+), 53 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 709557e..3116940 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1230,7 +1230,7 @@ int check_unsafe_exec(struct linux_binprm *bprm) bprm->unsafe = tracehook_unsafe_exec(p); n_fs = 1; - spin_lock(&p->fs->lock); + seq_spin_lock(&p->fs->lock); rcu_read_lock(); for (t = next_thread(p); t != p; t = next_thread(t)) { if (t->fs == p->fs) @@ -1247,7 +1247,7 @@ int check_unsafe_exec(struct linux_binprm *bprm) res = 1; } } - spin_unlock(&p->fs->lock); + seq_spin_unlock(&p->fs->lock); return res; } diff --git a/fs/fhandle.c b/fs/fhandle.c index 6b08864..9f437ac 100644 --- a/fs/fhandle.c +++ b/fs/fhandle.c @@ -115,10 +115,10 @@ static struct vfsmount *get_vfsmount_from_fd(int fd) if (fd == AT_FDCWD) { struct fs_struct *fs = current->fs; - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); path = fs->pwd; mntget(path.mnt); - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } else { int fput_needed; struct file *file = fget_light(fd, &fput_needed); diff --git a/fs/fs_struct.c b/fs/fs_struct.c index 78b519c..84db5f1 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -26,13 +26,11 @@ void set_fs_root(struct fs_struct *fs, struct path *path) { struct path old_root; - spin_lock(&fs->lock); - write_seqcount_begin(&fs->seq); + write_seqlock(&fs->lock); old_root = fs->root; fs->root = *path; path_get_longterm(path); - write_seqcount_end(&fs->seq); - spin_unlock(&fs->lock); + write_sequnlock(&fs->lock); if (old_root.dentry) path_put_longterm(&old_root); } @@ -45,13 +43,11 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path) { struct path old_pwd; - spin_lock(&fs->lock); - write_seqcount_begin(&fs->seq); + write_seqlock(&fs->lock); old_pwd = fs->pwd; fs->pwd = *path; path_get_longterm(path); - write_seqcount_end(&fs->seq); - spin_unlock(&fs->lock); + write_sequnlock(&fs->lock); if (old_pwd.dentry) path_put_longterm(&old_pwd); @@ -68,8 +64,7 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root) task_lock(p); fs = p->fs; if (fs) { - spin_lock(&fs->lock); - write_seqcount_begin(&fs->seq); + write_seqlock(&fs->lock); if (fs->root.dentry == old_root->dentry && fs->root.mnt == old_root->mnt) { path_get_longterm(new_root); @@ -82,8 +77,7 @@ void chroot_fs_refs(struct path *old_root, struct path *new_root) fs->pwd = *new_root; count++; } - write_seqcount_end(&fs->seq); - spin_unlock(&fs->lock); + write_sequnlock(&fs->lock); } task_unlock(p); } while_each_thread(g, p); @@ -106,12 +100,10 @@ void exit_fs(struct task_struct *tsk) if (fs) { int kill; task_lock(tsk); - spin_lock(&fs->lock); - write_seqcount_begin(&fs->seq); + write_seqlock(&fs->lock); tsk->fs = NULL; kill = !--fs->users; - write_seqcount_end(&fs->seq); - spin_unlock(&fs->lock); + write_sequnlock(&fs->lock); task_unlock(tsk); if (kill) free_fs_struct(fs); @@ -125,16 +117,15 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old) if (fs) { fs->users = 1; fs->in_exec = 0; - spin_lock_init(&fs->lock); - seqcount_init(&fs->seq); + seqlock_init(&fs->lock); fs->umask = old->umask; - spin_lock(&old->lock); + seq_spin_lock(&old->lock); fs->root = old->root; path_get_longterm(&fs->root); fs->pwd = old->pwd; path_get_longterm(&fs->pwd); - spin_unlock(&old->lock); + seq_spin_unlock(&old->lock); } return fs; } @@ -149,10 +140,10 @@ int unshare_fs_struct(void) return -ENOMEM; task_lock(current); - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); kill = !--fs->users; current->fs = new_fs; - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); task_unlock(current); if (kill) @@ -171,8 +162,7 @@ EXPORT_SYMBOL(current_umask); /* to be mentioned only in INIT_TASK */ struct fs_struct init_fs = { .users = 1, - .lock = __SPIN_LOCK_UNLOCKED(init_fs.lock), - .seq = SEQCNT_ZERO, + .lock = __SEQLOCK_UNLOCKED(init_fs.lock), .umask = 0022, }; @@ -185,14 +175,14 @@ void daemonize_fs_struct(void) task_lock(current); - spin_lock(&init_fs.lock); + seq_spin_lock(&init_fs.lock); init_fs.users++; - spin_unlock(&init_fs.lock); + seq_spin_unlock(&init_fs.lock); - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); current->fs = &init_fs; kill = !--fs->users; - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); task_unlock(current); if (kill) diff --git a/fs/namei.c b/fs/namei.c index f7593c0..b364372 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -424,7 +424,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) BUG_ON(!(nd->flags & LOOKUP_RCU)); if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) { want_root = 1; - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); if (nd->root.mnt != fs->root.mnt || nd->root.dentry != fs->root.dentry) goto err_root; @@ -454,7 +454,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry) spin_unlock(&parent->d_lock); if (want_root) { path_get(&nd->root); - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } mntget(nd->path.mnt); @@ -469,7 +469,7 @@ err_parent: spin_unlock(&parent->d_lock); err_root: if (want_root) - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); return -ECHILD; } @@ -619,10 +619,10 @@ static __always_inline void set_root_rcu(struct nameidata *nd) unsigned seq; do { - seq = read_seqcount_begin(&fs->seq); + seq = read_seqbegin(&fs->lock); nd->root = fs->root; nd->seq = __read_seqcount_begin(&nd->root.dentry->d_seq); - } while (read_seqcount_retry(&fs->seq, seq)); + } while (read_seqretry(&fs->lock, seq)); } } @@ -1501,10 +1501,10 @@ static int path_init(int dfd, const char *name, unsigned int flags, rcu_read_lock(); do { - seq = read_seqcount_begin(&fs->seq); + seq = read_seqbegin(&fs->lock); nd->path = fs->pwd; nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); - } while (read_seqcount_retry(&fs->seq, seq)); + } while (read_seqretry(&fs->lock, seq)); } else { get_fs_pwd(current->fs, &nd->path); } diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h index 003dc0f..f748403 100644 --- a/include/linux/fs_struct.h +++ b/include/linux/fs_struct.h @@ -2,13 +2,11 @@ #define _LINUX_FS_STRUCT_H #include -#include #include struct fs_struct { int users; - spinlock_t lock; - seqcount_t seq; + seqlock_t lock; int umask; int in_exec; struct path root, pwd; @@ -26,29 +24,29 @@ extern int unshare_fs_struct(void); static inline void get_fs_root(struct fs_struct *fs, struct path *root) { - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); *root = fs->root; path_get(root); - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } static inline void get_fs_pwd(struct fs_struct *fs, struct path *pwd) { - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); *pwd = fs->pwd; path_get(pwd); - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } static inline void get_fs_root_and_pwd(struct fs_struct *fs, struct path *root, struct path *pwd) { - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); *root = fs->root; path_get(root); *pwd = fs->pwd; path_get(pwd); - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } #endif /* _LINUX_FS_STRUCT_H */ diff --git a/kernel/fork.c b/kernel/fork.c index 0429130..1643f63 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -856,13 +856,13 @@ static int copy_fs(unsigned long clone_flags, struct task_struct *tsk) struct fs_struct *fs = current->fs; if (clone_flags & CLONE_FS) { /* tsk->fs is already what we want */ - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); if (fs->in_exec) { - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); return -EAGAIN; } fs->users++; - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); return 0; } tsk->fs = copy_fs_struct(fs); @@ -1729,13 +1729,13 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) if (new_fs) { fs = current->fs; - spin_lock(&fs->lock); + seq_spin_lock(&fs->lock); current->fs = new_fs; if (--fs->users) new_fs = NULL; else new_fs = fs; - spin_unlock(&fs->lock); + seq_spin_unlock(&fs->lock); } if (new_fd) { -- 1.7.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/