vsprintf: reduce code size by avoiding extra check

[safe/jmp/linux-2.6] / fs / 9p / vfs_dir.c

diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 276aed6..15cce53 100644 (file)
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -40,12 +40,30 @@
 #include "fid.h"
 
 /**
+ * struct p9_rdir - readdir accounting
+ * @mutex: mutex protecting readdir
+ * @head: start offset of current dirread buffer
+ * @tail: end offset of current dirread buffer
+ * @buf: dirread buffer
+ *
+ * private structure for keeping track of readdir
+ * allocated on demand
+ */
+
+struct p9_rdir {
+       struct mutex mutex;
+       int head;
+       int tail;
+       uint8_t *buf;
+};
+
+/**
  * dt_type - return file type
  * @mistat: mistat structure
  *
  */
 
-static inline int dt_type(struct p9_stat *mistat)
+static inline int dt_type(struct p9_wstat *mistat)
 {
        unsigned long perm = mistat->mode;
        int rettype = DT_REG;
@@ -69,53 +87,80 @@ static inline int dt_type(struct p9_stat *mistat)
 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
        int over;
-       struct p9_stat st;
-       int err;
+       struct p9_wstat st;
+       int err = 0;
        struct p9_fid *fid;
        int buflen;
-       char *statbuf;
-       int n, i = 0;
+       int reclen = 0;
+       struct p9_rdir *rdir;
 
        P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
        fid = filp->private_data;
 
        buflen = fid->clnt->msize - P9_IOHDRSZ;
-       statbuf = kmalloc(buflen, GFP_KERNEL);
-       if (!statbuf)
-               return -ENOMEM;
-
-       while (1) {
-               err = v9fs_file_readn(filp, statbuf, NULL, buflen,
-                                                               fid->rdir_fpos);
-               if (err <= 0)
-                       break;
-
-               n = err;
-               while (i < n) {
-                       err = p9_deserialize_stat(statbuf + i, buflen-i, &st,
-                                                       fid->clnt->dotu);
-                       if (!err) {
+
+       /* allocate rdir on demand */
+       if (!fid->rdir) {
+               rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
+
+               if (rdir == NULL) {
+                       err = -ENOMEM;
+                       goto exit;
+               }
+               spin_lock(&filp->f_dentry->d_lock);
+               if (!fid->rdir) {
+                       rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
+                       mutex_init(&rdir->mutex);
+                       rdir->head = rdir->tail = 0;
+                       fid->rdir = (void *) rdir;
+                       rdir = NULL;
+               }
+               spin_unlock(&filp->f_dentry->d_lock);
+               kfree(rdir);
+       }
+       rdir = (struct p9_rdir *) fid->rdir;
+
+       err = mutex_lock_interruptible(&rdir->mutex);
+       while (err == 0) {
+               if (rdir->tail == rdir->head) {
+                       err = v9fs_file_readn(filp, rdir->buf, NULL,
+                                                       buflen, filp->f_pos);
+                       if (err <= 0)
+                               goto unlock_and_exit;
+
+                       rdir->head = 0;
+                       rdir->tail = err;
+               }
+
+               while (rdir->head < rdir->tail) {
+                       err = p9stat_read(rdir->buf + rdir->head,
+                                               buflen - rdir->head, &st,
+                                               fid->clnt->dotu);
+                       if (err) {
+                               P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
                                err = -EIO;
-                               goto free_and_exit;
+                               p9stat_free(&st);
+                               goto unlock_and_exit;
                        }
+                       reclen = st.size+2;
 
-                       i += err;
-                       fid->rdir_fpos += err;
-
-                       over = filldir(dirent, st.name.str, st.name.len,
+                       over = filldir(dirent, st.name, strlen(st.name),
                            filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
 
-                       filp->f_pos += st.size;
+                       p9stat_free(&st);
 
                        if (over) {
                                err = 0;
-                               goto free_and_exit;
+                               goto unlock_and_exit;
                        }
+                       rdir->head += reclen;
+                       filp->f_pos += reclen;
                }
        }
 
-free_and_exit:
-       kfree(statbuf);
+unlock_and_exit:
+       mutex_unlock(&rdir->mutex);
+exit:
        return err;
 }