/* * 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, NULL, 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, NULL, 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 };