diff options
Diffstat (limited to 'fs/9p/xattr.c')
| -rw-r--r-- | fs/9p/xattr.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c new file mode 100644 index 000000000000..c434424be869 --- /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 +}; |