ubifs: Remove ui_mutex in ubifs_xattr_get and change_xattr

Since ubifs_xattr_get and ubifs_xattr_set cannot being executed
parallelly after importing @host_ui->xattr_sem, now we can remove
ui_mutex imported by commit ab92a20bce3b4c2 ("ubifs: make
ubifs_[get|set]xattr atomic").

@xattr_size, @xattr_names and @xattr_cnt can't be out of protection
by @host_ui->mutex yet, they are sill accesed in other places, such as
pack_inode() called by ubifs_write_inode() triggered by page-writeback.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 1fce27e9b7697312cca902795b73ed38b4ab4e2c..e4f193eae4b2b8d238878976b94dc024a6f9af8c 100644 (file)
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -208,13 +208,11 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
                err = -ENOMEM;
                goto out_free;
        }
-       mutex_lock(&ui->ui_mutex);
        kfree(ui->data);
        ui->data = buf;
        inode->i_size = ui->ui_size = size;
        old_size = ui->data_len;
        ui->data_len = size;
-       mutex_unlock(&ui->ui_mutex);
 
        mutex_lock(&host_ui->ui_mutex);
        host->i_ctime = current_time(host);
@@ -362,7 +360,6 @@ ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
        ubifs_assert(c, inode->i_size == ui->data_len);
        ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
 
-       mutex_lock(&ui->ui_mutex);
        if (buf) {
                /* If @buf is %NULL we are supposed to return the length */
                if (ui->data_len > size) {
@@ -375,7 +372,6 @@ ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
        err = ui->data_len;
 
 out_iput:
-       mutex_unlock(&ui->ui_mutex);
        iput(inode);
 out_cleanup:
        up_read(&ubifs_inode(host)->xattr_sem);