/* * 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 <linux/uio.h> #include <net/9p/9p.h> #include <net/9p/client.h> #include "fid.h" #include "xattr.h" ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name, void *buffer, size_t buffer_size) { ssize_t retval; u64 attr_size; struct p9_fid *attr_fid; struct kvec kvec = {.iov_base = buffer, .iov_len = buffer_size}; struct iov_iter to; int err; iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size); attr_fid = p9_client_xattrwalk(fid, name, &attr_size); if (IS_ERR(attr_fid)) { retval = PTR_ERR(attr_fid); p9_debug(P9_DEBUG_VFS, "p9_client_attrwalk failed %zd\n", retval); return retval; } if (attr_size > buffer_size) { if (!buffer_size) /* request to get the attr_size */ retval = attr_size; else retval = -ERANGE; } else { iov_iter_truncate(&to, attr_size); retval = p9_client_read(attr_fid, 0, &to, &err); if (err) retval = err; } p9_client_clunk(attr_fid); return retval; } /* * 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) { struct p9_fid *fid; p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu\n", name, buffer_size); fid = v9fs_fid_lookup(dentry); if (IS_ERR(fid)) return PTR_ERR(fid); return v9fs_fid_xattr_get(fid, name, buffer, buffer_size); } /* * 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) { struct p9_fid *fid = v9fs_fid_lookup(dentry); return v9fs_fid_xattr_set(fid, name, value, value_len, flags); } int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name, const void *value, size_t value_len, int flags) { struct kvec kvec = {.iov_base = (void *)value, .iov_len = value_len}; struct iov_iter from; int retval; iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len); p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n", name, value_len, flags); /* Clone it */ fid = clone_fid(fid); if (IS_ERR(fid)) return PTR_ERR(fid); /* * On success fid points to xattr */ retval = p9_client_xattrcreate(fid, name, value_len, flags); if (retval < 0) p9_debug(P9_DEBUG_VFS, "p9_client_xattrcreate failed %d\n", retval); else p9_client_write(fid, 0, &from, &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); } static int v9fs_xattr_handler_get(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size) { const char *full_name = xattr_full_name(handler, name); return v9fs_xattr_get(dentry, full_name, buffer, size); } static int v9fs_xattr_handler_set(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, const void *value, size_t size, int flags) { const char *full_name = xattr_full_name(handler, name); return v9fs_xattr_set(dentry, full_name, value, size, flags); } static struct xattr_handler v9fs_xattr_user_handler = { .prefix = XATTR_USER_PREFIX, .get = v9fs_xattr_handler_get, .set = v9fs_xattr_handler_set, }; static struct xattr_handler v9fs_xattr_trusted_handler = { .prefix = XATTR_TRUSTED_PREFIX, .get = v9fs_xattr_handler_get, .set = v9fs_xattr_handler_set, }; #ifdef CONFIG_9P_FS_SECURITY static struct xattr_handler v9fs_xattr_security_handler = { .prefix = XATTR_SECURITY_PREFIX, .get = v9fs_xattr_handler_get, .set = v9fs_xattr_handler_set, }; #endif const struct xattr_handler *v9fs_xattr_handlers[] = { &v9fs_xattr_user_handler, &v9fs_xattr_trusted_handler, #ifdef CONFIG_9P_FS_POSIX_ACL &v9fs_xattr_acl_access_handler, &v9fs_xattr_acl_default_handler, #endif #ifdef CONFIG_9P_FS_SECURITY &v9fs_xattr_security_handler, #endif NULL };