btrfs: try harder to allocate raid56 stripe cache
[linux-3.10.git] / fs / 9p / vfs_dir.c
index d7d0ac5..ff911e7 100644 (file)
@@ -32,6 +32,7 @@
 #include <linux/sched.h>
 #include <linux/inet.h>
 #include <linux/idr.h>
+#include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
 #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;
@@ -58,6 +77,51 @@ static inline int dt_type(struct p9_stat *mistat)
        return rettype;
 }
 
+static void p9stat_init(struct p9_wstat *stbuf)
+{
+       stbuf->name  = NULL;
+       stbuf->uid   = NULL;
+       stbuf->gid   = NULL;
+       stbuf->muid  = NULL;
+       stbuf->extension = NULL;
+}
+
+/**
+ * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
+ * @filp: opened file structure
+ * @buflen: Length in bytes of buffer to allocate
+ *
+ */
+
+static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
+{
+       struct p9_rdir *rdir;
+       struct p9_fid *fid;
+       int err = 0;
+
+       fid = filp->private_data;
+       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);
+       }
+exit:
+       return err;
+}
+
 /**
  * v9fs_dir_readdir - read a directory
  * @filp: opened file structure
@@ -69,53 +133,147 @@ 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);
+       p9_debug(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, fid->rdir_fpos,
-                                                                       buflen);
-               if (err <= 0)
-                       break;
-
-               n = err;
-               while (i < n) {
-                       err = p9_deserialize_stat(statbuf + i, buflen-i, &st,
-                                                       fid->clnt->dotu);
-                       if (!err) {
+
+       err = v9fs_alloc_rdir_buf(filp, buflen);
+       if (err)
+               goto exit;
+       rdir = (struct p9_rdir *) fid->rdir;
+
+       err = mutex_lock_interruptible(&rdir->mutex);
+       if (err)
+               return err;
+       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) {
+                       p9stat_init(&st);
+                       err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
+                                         rdir->tail - rdir->head, &st);
+                       if (err) {
+                               p9_debug(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 unlock_and_exit;
+                       }
+                       rdir->head += reclen;
+                       filp->f_pos += reclen;
+               }
+       }
+
+unlock_and_exit:
+       mutex_unlock(&rdir->mutex);
+exit:
+       return err;
+}
+
+/**
+ * v9fs_dir_readdir_dotl - read a directory
+ * @filp: opened file structure
+ * @dirent: buffer to fill dirent structures
+ * @filldir: function to populate dirent structures
+ *
+ */
+static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
+                                               filldir_t filldir)
+{
+       int over;
+       int err = 0;
+       struct p9_fid *fid;
+       int buflen;
+       struct p9_rdir *rdir;
+       struct p9_dirent curdirent;
+       u64 oldoffset = 0;
+
+       p9_debug(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+       fid = filp->private_data;
+
+       buflen = fid->clnt->msize - P9_READDIRHDRSZ;
+
+       err = v9fs_alloc_rdir_buf(filp, buflen);
+       if (err)
+               goto exit;
+       rdir = (struct p9_rdir *) fid->rdir;
+
+       err = mutex_lock_interruptible(&rdir->mutex);
+       if (err)
+               return err;
+
+       while (err == 0) {
+               if (rdir->tail == rdir->head) {
+                       err = p9_client_readdir(fid, rdir->buf, buflen,
+                                               filp->f_pos);
+                       if (err <= 0)
+                               goto unlock_and_exit;
+
+                       rdir->head = 0;
+                       rdir->tail = err;
+               }
+
+               while (rdir->head < rdir->tail) {
+
+                       err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
+                                           rdir->tail - rdir->head,
+                                           &curdirent);
+                       if (err < 0) {
+                               p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
+                               err = -EIO;
+                               goto unlock_and_exit;
+                       }
+
+                       /* d_off in dirent structure tracks the offset into
+                        * the next dirent in the dir. However, filldir()
+                        * expects offset into the current dirent. Hence
+                        * while calling filldir send the offset from the
+                        * previous dirent structure.
+                        */
+                       over = filldir(dirent, curdirent.d_name,
+                                       strlen(curdirent.d_name),
+                                       oldoffset, v9fs_qid2ino(&curdirent.qid),
+                                       curdirent.d_type);
+                       oldoffset = curdirent.d_off;
 
                        if (over) {
                                err = 0;
-                               goto free_and_exit;
+                               goto unlock_and_exit;
                        }
+
+                       filp->f_pos = curdirent.d_off;
+                       rdir->head += err;
                }
        }
 
-free_and_exit:
-       kfree(statbuf);
+unlock_and_exit:
+       mutex_unlock(&rdir->mutex);
+exit:
        return err;
 }
 
@@ -132,10 +290,10 @@ int v9fs_dir_release(struct inode *inode, struct file *filp)
        struct p9_fid *fid;
 
        fid = filp->private_data;
-       P9_DPRINTK(P9_DEBUG_VFS,
-                       "inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
-       filemap_write_and_wait(inode->i_mapping);
-       p9_client_clunk(fid);
+       p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
+                inode, filp, fid ? fid->fid : -1);
+       if (fid)
+               p9_client_clunk(fid);
        return 0;
 }
 
@@ -146,3 +304,12 @@ const struct file_operations v9fs_dir_operations = {
        .open = v9fs_file_open,
        .release = v9fs_dir_release,
 };
+
+const struct file_operations v9fs_dir_operations_dotl = {
+       .read = generic_read_dir,
+       .llseek = generic_file_llseek,
+       .readdir = v9fs_dir_readdir_dotl,
+       .open = v9fs_file_open,
+       .release = v9fs_dir_release,
+        .fsync = v9fs_file_fsync_dotl,
+};