diff options
Diffstat (limited to 'fs/9p/xattr.c')
| -rw-r--r-- | fs/9p/xattr.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c new file mode 100644 index 000000000..0cf44b6cc --- /dev/null +++ b/fs/9p/xattr.c @@ -0,0 +1,151 @@ +/* + * 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); + if (IS_ERR(fid)) + return PTR_ERR(fid); + 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 = p9_client_walk(fid, 0, NULL, 1); + 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); +} + +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 +}; |