fs/9p: Add support user. xattr
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
new file mode 100644
index 0000000..c434424
--- /dev/null
+++ b/fs/9p/xattr.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright IBM Corporation, 2010
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "fid.h"
+#include "xattr.h"
+
+/*
+ * v9fs_xattr_get()
+ *
+ * Copy an extended attribute into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ ssize_t retval;
+ int msize, read_count;
+ u64 offset = 0, attr_size;
+ struct p9_fid *fid, *attr_fid;
+
+ P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu\n",
+ __func__, name, buffer_size);
+
+ fid = v9fs_fid_lookup(dentry);
+ if (IS_ERR(fid))
+ return PTR_ERR(fid);
+
+ attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
+ if (IS_ERR(attr_fid)) {
+ retval = PTR_ERR(attr_fid);
+ P9_DPRINTK(P9_DEBUG_VFS,
+ "p9_client_attrwalk failed %zd\n", retval);
+ attr_fid = NULL;
+ goto error;
+ }
+ if (!buffer_size) {
+ /* request to get the attr_size */
+ retval = attr_size;
+ goto error;
+ }
+ if (attr_size > buffer_size) {
+ retval = -ERANGE;
+ goto error;
+ }
+ msize = attr_fid->clnt->msize;
+ while (attr_size) {
+ if (attr_size > (msize - P9_IOHDRSZ))
+ read_count = msize - P9_IOHDRSZ;
+ else
+ read_count = attr_size;
+ read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
+ 0, offset, read_count);
+ if (read_count < 0) {
+ /* error in xattr read */
+ retval = read_count;
+ goto error;
+ }
+ offset += read_count;
+ attr_size -= read_count;
+ }
+ /* Total read xattr bytes */
+ retval = offset;
+error:
+ if (attr_fid)
+ p9_client_clunk(attr_fid);
+ return retval;
+
+}
+
+/*
+ * v9fs_xattr_set()
+ *
+ * Create, replace or remove an extended attribute for this inode. Buffer
+ * is NULL to remove an existing extended attribute, and non-NULL to
+ * either replace an existing extended attribute, or create a new extended
+ * attribute. The flags XATTR_REPLACE and XATTR_CREATE
+ * specify that an extended attribute must exist and must not exist
+ * previous to the call, respectively.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int v9fs_xattr_set(struct dentry *dentry, const char *name,
+ const void *value, size_t value_len, int flags)
+{
+ u64 offset = 0;
+ int retval, msize, write_count;
+ struct p9_fid *fid = NULL;
+
+ P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu flags = %d\n",
+ __func__, name, value_len, flags);
+
+ fid = v9fs_fid_clone(dentry);
+ if (IS_ERR(fid)) {
+ retval = PTR_ERR(fid);
+ fid = NULL;
+ goto error;
+ }
+ /*
+ * On success fid points to xattr
+ */
+ retval = p9_client_xattrcreate(fid, name, value_len, flags);
+ if (retval < 0) {
+ P9_DPRINTK(P9_DEBUG_VFS,
+ "p9_client_xattrcreate failed %d\n", retval);
+ goto error;
+ }
+ msize = fid->clnt->msize;;
+ while (value_len) {
+ if (value_len > (msize - P9_IOHDRSZ))
+ write_count = msize - P9_IOHDRSZ;
+ else
+ write_count = value_len;
+ write_count = p9_client_write(fid, ((char *)value)+offset,
+ 0, offset, write_count);
+ if (write_count < 0) {
+ /* error in xattr write */
+ retval = write_count;
+ goto error;
+ }
+ offset += write_count;
+ value_len -= write_count;
+ }
+ /* Total read xattr bytes */
+ retval = offset;
+error:
+ if (fid)
+ retval = p9_client_clunk(fid);
+ return retval;
+}
+
+ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ return v9fs_xattr_get(dentry, NULL, buffer, buffer_size);
+}
+
+const struct xattr_handler *v9fs_xattr_handlers[] = {
+ &v9fs_xattr_user_handler,
+ NULL
+};