merge path_init and path_init_rcu
Actual dependency on whether we want RCU or not is in 3 small areas (as it ought to be) and everything around those is the same in both versions. Since each function has only one caller and those callers are on two sides of if (flags & LOOKUP_RCU), it's easier and cleaner to merge them and pull the checks inside. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
Родитель
ee0827cd6b
Коммит
e41f7d4ee5
120
fs/namei.c
120
fs/namei.c
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@ -1520,80 +1520,6 @@ return_err:
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return err;
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}
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static int path_init_rcu(int dfd, const char *name, unsigned int flags, struct nameidata *nd)
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{
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int retval = 0;
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int fput_needed;
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struct file *file;
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nd->last_type = LAST_ROOT; /* if there are only slashes... */
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nd->flags = flags | LOOKUP_RCU;
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nd->depth = 0;
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nd->root.mnt = NULL;
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nd->file = NULL;
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if (*name=='/') {
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struct fs_struct *fs = current->fs;
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unsigned seq;
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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do {
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seq = read_seqcount_begin(&fs->seq);
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nd->root = fs->root;
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nd->path = nd->root;
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nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
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} while (read_seqcount_retry(&fs->seq, seq));
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} else if (dfd == AT_FDCWD) {
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struct fs_struct *fs = current->fs;
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unsigned seq;
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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do {
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seq = read_seqcount_begin(&fs->seq);
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nd->path = fs->pwd;
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nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
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} while (read_seqcount_retry(&fs->seq, seq));
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} else {
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struct dentry *dentry;
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file = fget_light(dfd, &fput_needed);
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retval = -EBADF;
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if (!file)
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goto out_fail;
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dentry = file->f_path.dentry;
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retval = -ENOTDIR;
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if (!S_ISDIR(dentry->d_inode->i_mode))
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goto fput_fail;
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retval = file_permission(file, MAY_EXEC);
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if (retval)
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goto fput_fail;
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nd->path = file->f_path;
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if (fput_needed)
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nd->file = file;
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nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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}
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nd->inode = nd->path.dentry->d_inode;
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return 0;
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fput_fail:
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fput_light(file, fput_needed);
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out_fail:
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return retval;
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}
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static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd)
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{
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int retval = 0;
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@ -1604,13 +1530,34 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei
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nd->flags = flags;
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nd->depth = 0;
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nd->root.mnt = NULL;
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nd->file = NULL;
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if (*name=='/') {
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set_root(nd);
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if (flags & LOOKUP_RCU) {
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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set_root_rcu(nd);
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} else {
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set_root(nd);
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path_get(&nd->root);
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}
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nd->path = nd->root;
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path_get(&nd->root);
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} else if (dfd == AT_FDCWD) {
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get_fs_pwd(current->fs, &nd->path);
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if (flags & LOOKUP_RCU) {
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struct fs_struct *fs = current->fs;
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unsigned seq;
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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do {
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seq = read_seqcount_begin(&fs->seq);
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nd->path = fs->pwd;
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nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
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} while (read_seqcount_retry(&fs->seq, seq));
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} else {
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get_fs_pwd(current->fs, &nd->path);
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}
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} else {
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struct dentry *dentry;
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@ -1630,10 +1577,18 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei
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goto fput_fail;
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nd->path = file->f_path;
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path_get(&file->f_path);
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fput_light(file, fput_needed);
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if (flags & LOOKUP_RCU) {
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if (fput_needed)
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nd->file = file;
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nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
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br_read_lock(vfsmount_lock);
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rcu_read_lock();
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} else {
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path_get(&file->f_path);
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fput_light(file, fput_needed);
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}
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}
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nd->inode = nd->path.dentry->d_inode;
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return 0;
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@ -1663,10 +1618,7 @@ static int path_lookupat(int dfd, const char *name,
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* be handled by restarting a traditional ref-walk (which will always
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* be able to complete).
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*/
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if (flags & LOOKUP_RCU)
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retval = path_init_rcu(dfd, name, flags, nd);
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else
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retval = path_init(dfd, name, flags, nd);
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retval = path_init(dfd, name, flags, nd);
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if (unlikely(retval))
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return retval;
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