summaryrefslogtreecommitdiff
path: root/fs/9p/vfs_dir.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/9p/vfs_dir.c')
-rw-r--r--fs/9p/vfs_dir.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
new file mode 100644
index 00000000..ff911e77
--- /dev/null
+++ b/fs/9p/vfs_dir.c
@@ -0,0 +1,315 @@
+/*
+ * linux/fs/9p/vfs_dir.c
+ *
+ * This file contains vfs directory ops for the 9P2000 protocol.
+ *
+ * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to:
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA 02111-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#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 "v9fs.h"
+#include "v9fs_vfs.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_wstat *mistat)
+{
+ unsigned long perm = mistat->mode;
+ int rettype = DT_REG;
+
+ if (perm & P9_DMDIR)
+ rettype = DT_DIR;
+ if (perm & P9_DMSYMLINK)
+ rettype = DT_LNK;
+
+ 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
+ * @dirent: directory structure ???
+ * @filldir: function to populate directory structure ???
+ *
+ */
+
+static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ int over;
+ struct p9_wstat st;
+ int err = 0;
+ struct p9_fid *fid;
+ int buflen;
+ int reclen = 0;
+ struct p9_rdir *rdir;
+
+ 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;
+
+ 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;
+ p9stat_free(&st);
+ goto unlock_and_exit;
+ }
+ reclen = st.size+2;
+
+ over = filldir(dirent, st.name, strlen(st.name),
+ filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
+
+ 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 unlock_and_exit;
+ }
+
+ filp->f_pos = curdirent.d_off;
+ rdir->head += err;
+ }
+ }
+
+unlock_and_exit:
+ mutex_unlock(&rdir->mutex);
+exit:
+ return err;
+}
+
+
+/**
+ * v9fs_dir_release - close a directory
+ * @inode: inode of the directory
+ * @filp: file pointer to a directory
+ *
+ */
+
+int v9fs_dir_release(struct inode *inode, struct file *filp)
+{
+ struct p9_fid *fid;
+
+ fid = filp->private_data;
+ 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;
+}
+
+const struct file_operations v9fs_dir_operations = {
+ .read = generic_read_dir,
+ .llseek = generic_file_llseek,
+ .readdir = v9fs_dir_readdir,
+ .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,
+};
generated by cgit (git 2.34.1) at 2025-01-19 18:49:58 +0000