Ext4: Make file creation time, i_version and i_generation available by xattrs

Message ID	20100628162626.6026.26679.stgit@warthog.procyon.org.uk
State	New, archived
Headers	show Return-Path: <linux-ext4-owner@vger.kernel.org> Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells <dhowells@redhat.com> Subject: [PATCH] Ext4: Make file creation time, i_version and i_generation available by xattrs To: viro@ZenIV.linux.org.uk, smfrench@gmail.com, jlayton@redhat.com, mcao@us.ibm.com, aneesh.kumar@linux.vnet.ibm.com Cc: dhowells@redhat.com, linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, samba-technical@lists.samba.org, sjayaraman@suse.de, linux-ext4@vger.kernel.org Date: Mon, 28 Jun 2010 17:26:27 +0100 Message-ID: <20100628162626.6026.26679.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index 8867b2a..034dd27 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -8,6 +8,8 @@ ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \ ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o -ext4-$(CONFIG_EXT4_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o +ext4-$(CONFIG_EXT4_FS_XATTR) += \ + xattr.o xattr_user.o xattr_trusted.o xattr_file.o + ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 0433800..1360f7c 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -111,6 +111,7 @@ static const struct xattr_handler *ext4_xattr_handler_map[] = { const struct xattr_handler *ext4_xattr_handlers[] = { &ext4_xattr_user_handler, + &ext4_xattr_file_handler, &ext4_xattr_trusted_handler, #ifdef CONFIG_EXT4_FS_POSIX_ACL &ext4_xattr_acl_access_handler, @@ -427,23 +428,35 @@ cleanup: static int ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) { - int i_error, b_error; + int ret, result = 0; down_read(&EXT4_I(dentry->d_inode)->xattr_sem); - i_error = ext4_xattr_ibody_list(dentry, buffer, buffer_size); - if (i_error < 0) { - b_error = 0; - } else { - if (buffer) { - buffer += i_error; - buffer_size -= i_error; - } - b_error = ext4_xattr_block_list(dentry, buffer, buffer_size); - if (b_error < 0) - i_error = 0; + ret = ext4_xattr_ibody_list(dentry, buffer, buffer_size); + if (ret < 0) + goto error; + result += ret; + if (buffer) { + buffer += ret; + buffer_size -= ret; + } + + ret = ext4_xattr_block_list(dentry, buffer, buffer_size); + if (ret < 0) + goto error; + result += ret; + if (buffer) { + buffer += ret; + buffer_size -= ret; } + + ret = ext4_xattr_file_list(dentry, buffer, buffer_size); + if (ret < 0) + goto error; + result += ret; + +error: up_read(&EXT4_I(dentry->d_inode)->xattr_sem); - return i_error + b_error; + return ret < 0 ? ret : result; } /* diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 518e96e..f0e3aaf 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -66,12 +66,14 @@ struct ext4_xattr_entry { # ifdef CONFIG_EXT4_FS_XATTR extern const struct xattr_handler ext4_xattr_user_handler; +extern const struct xattr_handler ext4_xattr_file_handler; extern const struct xattr_handler ext4_xattr_trusted_handler; extern const struct xattr_handler ext4_xattr_acl_access_handler; extern const struct xattr_handler ext4_xattr_acl_default_handler; extern const struct xattr_handler ext4_xattr_security_handler; extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); +extern int ext4_xattr_file_list(struct dentry *, char *, size_t); extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); diff --git a/fs/ext4/xattr_file.c b/fs/ext4/xattr_file.c new file mode 100644 index 0000000..81044c5 --- /dev/null +++ b/fs/ext4/xattr_file.c @@ -0,0 +1,108 @@ +/* File-specific xattrs + * + * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/capability.h> +#include <linux/fs.h> +#include "ext4_jbd2.h" +#include "ext4.h" +#include "xattr.h" + +static const char *ext4_file_xattrs[] = { + "crtime", + "i_generation" +}; + +static const char *ext4_dir_xattrs[] = { + "i_version", +}; + +int +ext4_xattr_file_list(struct dentry *dentry, char *list, size_t list_size) +{ + struct ext4_inode_info *ei = EXT4_I(dentry->d_inode); + const size_t prefix_len = XATTR_FILE_PREFIX_LEN; + int total_len = 0; + int loop; + + for (loop = 0; loop < ARRAY_SIZE(ext4_file_xattrs); loop++) { + const char *fxname = ext4_file_xattrs[loop]; + int fxnlen = strlen(fxname); + + total_len += prefix_len + fxnlen + 1; + if (list && total_len <= list_size) { + memcpy(list, XATTR_FILE_PREFIX, prefix_len); + list += prefix_len; + memcpy(list, fxname, fxnlen + 1); + list += fxnlen + 1; + } + } + + if (!S_ISDIR(ei->vfs_inode.i_mode)) + goto out; + + /* Ext4 only supports i_version on directories */ + for (loop = 0; loop < ARRAY_SIZE(ext4_dir_xattrs); loop++) { + const char *fxname = ext4_dir_xattrs[loop]; + int fxnlen = strlen(fxname); + + total_len += prefix_len + fxnlen + 1; + if (list && total_len <= list_size) { + memcpy(list, XATTR_FILE_PREFIX, prefix_len); + list += prefix_len; + memcpy(list, fxname, fxnlen + 1); + list += fxnlen + 1; + } + } + +out: + return total_len; +} + +static int +ext4_xattr_file_get(struct dentry *dentry, const char *name, void *buffer, + size_t size, int type) +{ + struct ext4_inode_info *ei = EXT4_I(dentry->d_inode); + size_t result_size; + union { + struct timespec ts; + u64 val; + } result; + + if (strcmp(name, "crtime") == 0) { + result_size = sizeof(struct timespec); + result.ts = ei->i_crtime; + } else if (strcmp(name, "i_version") == 0) { + if (!S_ISDIR(ei->vfs_inode.i_mode)) + return -ENOTDIR; + result_size = sizeof(u64); + result.val = ei->vfs_inode.i_version; + } else if (strcmp(name, "i_generation") == 0) { + result_size = sizeof(u64); + result.val = ei->vfs_inode.i_generation; + } else { + return -EINVAL; + } + + if (size == 0) + return result_size; + if (size < result_size) + return -E2BIG; + memcpy(buffer, &result, result_size); + return result_size; +} + +const struct xattr_handler ext4_xattr_file_handler = { + .prefix = XATTR_FILE_PREFIX, + .get = ext4_xattr_file_get, +}; diff --git a/include/linux/xattr.h b/include/linux/xattr.h index 0cfa1e9..e52a8ce 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -33,6 +33,9 @@ #define XATTR_USER_PREFIX "user." #define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1) +#define XATTR_FILE_PREFIX "file." +#define XATTR_FILE_PREFIX_LEN (sizeof (XATTR_FILE_PREFIX) - 1) + struct inode; struct dentry;

Ext4: Make file creation time, i_version and i_generation available by xattrs

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