From 2be7828c9fefc8cd205d1948faac48da8ce6c2ef Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 8 Mar 2021 10:16:16 -0500 Subject: [PATCH] get rid of autofs_getpath() allow wq->name.name to point not at the beginning of the object containing the string, with wq->offset telling how far into it we are. Then we can bloody well just use dentry_path_raw() instead of autofs_getpath() - the only real difference is that dentry_path_raw() puts the result into the end of buffer and returns where it starts. Signed-off-by: Al Viro --- fs/autofs/autofs_i.h | 1 + fs/autofs/waitq.c | 72 ++++++++++++---------------------------------------- 2 files changed, 17 insertions(+), 56 deletions(-) diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h index 054f97b..918826e 100644 --- a/fs/autofs/autofs_i.h +++ b/fs/autofs/autofs_i.h @@ -87,6 +87,7 @@ struct autofs_wait_queue { autofs_wqt_t wait_queue_token; /* We use the following to see what we are waiting for */ struct qstr name; + u32 offset; u32 dev; u64 ino; kuid_t uid; diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c index 5ced859..16b5fca 100644 --- a/fs/autofs/waitq.c +++ b/fs/autofs/waitq.c @@ -30,7 +30,7 @@ void autofs_catatonic_mode(struct autofs_sb_info *sbi) while (wq) { nwq = wq->next; wq->status = -ENOENT; /* Magic is gone - report failure */ - kfree(wq->name.name); + kfree(wq->name.name - wq->offset); wq->name.name = NULL; wq->wait_ctr--; wake_up_interruptible(&wq->queue); @@ -175,51 +175,6 @@ static void autofs_notify_daemon(struct autofs_sb_info *sbi, fput(pipe); } -static int autofs_getpath(struct autofs_sb_info *sbi, - struct dentry *dentry, char *name) -{ - struct dentry *root = sbi->sb->s_root; - struct dentry *tmp; - char *buf; - char *p; - int len; - unsigned seq; - -rename_retry: - buf = name; - len = 0; - - seq = read_seqbegin(&rename_lock); - rcu_read_lock(); - spin_lock(&sbi->fs_lock); - for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) - len += tmp->d_name.len + 1; - - if (!len || --len > NAME_MAX) { - spin_unlock(&sbi->fs_lock); - rcu_read_unlock(); - if (read_seqretry(&rename_lock, seq)) - goto rename_retry; - return 0; - } - - *(buf + len) = '\0'; - p = buf + len - dentry->d_name.len; - strncpy(p, dentry->d_name.name, dentry->d_name.len); - - for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) { - *(--p) = '/'; - p -= tmp->d_name.len; - strncpy(p, tmp->d_name.name, tmp->d_name.len); - } - spin_unlock(&sbi->fs_lock); - rcu_read_unlock(); - if (read_seqretry(&rename_lock, seq)) - goto rename_retry; - - return len; -} - static struct autofs_wait_queue * autofs_find_wait(struct autofs_sb_info *sbi, const struct qstr *qstr) { @@ -352,6 +307,7 @@ int autofs_wait(struct autofs_sb_info *sbi, struct qstr qstr; char *name; int status, ret, type; + unsigned int offset = 0; pid_t pid; pid_t tgid; @@ -389,20 +345,23 @@ int autofs_wait(struct autofs_sb_info *sbi, return -ENOMEM; /* If this is a direct mount request create a dummy name */ - if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type)) + if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type)) { + qstr.name = name; qstr.len = sprintf(name, "%p", dentry); - else { - qstr.len = autofs_getpath(sbi, dentry, name); - if (!qstr.len) { + } else { + char *p = dentry_path_raw(dentry, name, NAME_MAX); + if (IS_ERR(p)) { kfree(name); return -ENOENT; } + qstr.name = ++p; // skip the leading slash + qstr.len = strlen(p); + offset = p - name; } - qstr.name = name; qstr.hash = full_name_hash(dentry, name, qstr.len); if (mutex_lock_interruptible(&sbi->wq_mutex)) { - kfree(qstr.name); + kfree(name); return -EINTR; } @@ -410,7 +369,7 @@ int autofs_wait(struct autofs_sb_info *sbi, if (ret <= 0) { if (ret != -EINTR) mutex_unlock(&sbi->wq_mutex); - kfree(qstr.name); + kfree(name); return ret; } @@ -418,7 +377,7 @@ int autofs_wait(struct autofs_sb_info *sbi, /* Create a new wait queue */ wq = kmalloc(sizeof(struct autofs_wait_queue), GFP_KERNEL); if (!wq) { - kfree(qstr.name); + kfree(name); mutex_unlock(&sbi->wq_mutex); return -ENOMEM; } @@ -430,6 +389,7 @@ int autofs_wait(struct autofs_sb_info *sbi, sbi->queues = wq; init_waitqueue_head(&wq->queue); memcpy(&wq->name, &qstr, sizeof(struct qstr)); + wq->offset = offset; wq->dev = autofs_get_dev(sbi); wq->ino = autofs_get_ino(sbi); wq->uid = current_uid(); @@ -469,7 +429,7 @@ int autofs_wait(struct autofs_sb_info *sbi, (unsigned long) wq->wait_queue_token, wq->name.len, wq->name.name, notify); mutex_unlock(&sbi->wq_mutex); - kfree(qstr.name); + kfree(name); } /* @@ -540,7 +500,7 @@ int autofs_wait_release(struct autofs_sb_info *sbi, } *wql = wq->next; /* Unlink from chain */ - kfree(wq->name.name); + kfree(wq->name.name - wq->offset); wq->name.name = NULL; /* Do not wait on this queue */ wq->status = status; wake_up(&wq->queue); -- 2.7.4