From patchwork Thu Jun 19 23:24:25 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Sandeen X-Patchwork-Id: 362037 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id DC33C140092 for ; Fri, 20 Jun 2014 09:24:27 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965786AbaFSXY0 (ORCPT ); Thu, 19 Jun 2014 19:24:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33656 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965467AbaFSXY0 (ORCPT ); Thu, 19 Jun 2014 19:24:26 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s5JNOQqr027947 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 19 Jun 2014 19:24:26 -0400 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s5JNOPJa006908 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Thu, 19 Jun 2014 19:24:26 -0400 Message-ID: <53A37129.2040409@redhat.com> Date: Thu, 19 Jun 2014 18:24:25 -0500 From: Eric Sandeen User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: ext4 development Subject: [PATCH 2/2] e2fsprogs: revise and extend chattr(1) and chattr usage() References: <53A36F0E.6090105@redhat.com> In-Reply-To: <53A36F0E.6090105@redhat.com> X-Enigmail-Version: 1.6 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org The chattr(1) manpage and chattr usage() output were missing some flags. Add those, and make some other minor cosmetic fixes. (I've left out the 'B' (EXT2_COMPRBLK_FL) flag, because it's not actually used anywhere, and I can't figure out how it differs from 'c' (EXT2_COMPR_FL)) Also, because the matrix of filesystems & flags is quite large, refer to filesystem-specific manpages for detailed discussion of flags supported by those filesystems, rather than trying to cover it all in this manpage. I'll send those manpage updates to the appropriate lists a bit later. Signed-off-by: Eric Sandeen --- -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/misc/chattr.1.in b/misc/chattr.1.in index ce426e8..6f64e09 100644 --- a/misc/chattr.1.in +++ b/misc/chattr.1.in @@ -47,8 +47,17 @@ but not modified by chattr: compression error (E), huge file (h), indexed directory (I), +inline data (N), compression raw access (X), and compressed dirty file (Z). +.PP +Not all flags are supported or utilized by all filesystems; refer to +filesystem-specific man pages such as +.BR btrfs (5), +.BR ext4 (5), +and +.BR xfs (5) +for more filesystem-specific details. .SH OPTIONS .TP .B \-R @@ -67,7 +76,7 @@ A file with the `a' attribute set can only be open in append mode for writing. Only the superuser or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute. .PP -When a file with the 'A' attribute set is accessed, its atime record is +When a file with the `A' attribute set is accessed, its atime record is not modified. This avoids a certain amount of disk I/O for laptop systems. .PP @@ -77,12 +86,12 @@ this file compresses data before storing them on the disk. Note: please make sure to read the bugs and limitations section at the end of this document. .PP -A file with the 'C' attribute set will not be subject to copy-on-write +A file with the `C' attribute set will not be subject to copy-on-write updates. This flag is only supported on file systems which perform -copy-on-write. (Note: For btrfs, the 'C' flag should be +copy-on-write. (Note: For btrfs, the `C' flag should be set on new or empty files. If it is set on a file which already has data blocks, it is undefined when the blocks assigned to the file will -be fully stable. If the 'C' flag is set on a directory, it will have no +be fully stable. If the `C' flag is set on a directory, it will have no effect on the directory, but new files created in that directory will the No_COW attribute.) .PP @@ -94,18 +103,18 @@ When a directory with the `D' attribute set is modified, the changes are written synchronously on the disk; this is equivalent to the `dirsync' mount option applied to a subset of the files. .PP -The 'e' attribute indicates that the file is using extents for mapping +The `e' attribute indicates that the file is using extents for mapping the blocks on disk. It may not be removed using .BR chattr (1). .PP -The 'E' attribute is used by the experimental compression patches to +The `E' attribute is used by the experimental compression patches to indicate that a compressed file has a compression error. It may not be set or reset using .BR chattr (1), although it can be displayed by .BR lsattr (1). .PP -The 'h' attribute indicates the file is storing its blocks in units of the +The `h' attribute indicates the file is storing its blocks in units of the filesystem blocksize instead of in units of sectors, and means that the file is (or at one time was) larger than 2TB. It may not be set or reset using .BR chattr (1), @@ -117,7 +126,7 @@ renamed, no link can be created to this file and no data can be written to the file. Only the superuser or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute. .PP -The 'I' attribute is used by the htree code to indicate that a directory +The `I' attribute is used by the htree code to indicate that a directory is being indexed using hashed trees. It may not be set or reset using .BR chattr (1), although it can be displayed by @@ -131,6 +140,12 @@ is already journalled and this attribute has no effect. Only the superuser or a process possessing the CAP_SYS_RESOURCE capability can set or clear this attribute. .PP +A file with the `N' attribute set indicates that the file has data +stored inline, within the inode itself. It may not be set or reset using +.BR chattr (1), +although it can be displayed by +.BR lsattr (1). +.PP When a file with the `s' attribute set is deleted, its blocks are zeroed and written back to the disk. Note: please make sure to read the bugs and limitations section at the end of this document. @@ -139,19 +154,19 @@ When a file with the `S' attribute set is modified, the changes are written synchronously on the disk; this is equivalent to the `sync' mount option applied to a subset of the files. .PP -A file with the 't' attribute will not have a partial block fragment at +A file with the `t' attribute will not have a partial block fragment at the end of the file merged with other files (for those filesystems which support tail-merging). This is necessary for applications such as LILO which read the filesystem directly, and which don't understand tail-merged files. Note: As of this writing, the ext2 or ext3 filesystems do not (yet, except in very experimental patches) support tail-merging. .PP -A directory with the 'T' attribute will be deemed to be the top of +A directory with the `T' attribute will be deemed to be the top of directory hierarchies for the purposes of the Orlov block allocator. This is a hint to the block allocator used by ext3 and ext4 that the subdirectories under this directory are not related, and thus should be spread apart for allocation purposes. For example it is a very good -idea to set the 'T' attribute on the /home directory, so that /home/john +idea to set the `T' attribute on the /home directory, so that /home/john and /home/mary are placed into separate block groups. For directories where this attribute is not set, the Orlov block allocator will try to group subdirectories closer together where possible. @@ -161,14 +176,14 @@ saved. This allows the user to ask for its undeletion. Note: please make sure to read the bugs and limitations section at the end of this document. .PP -The 'X' attribute is used by the experimental compression patches to -indicate that a raw contents of a compressed file can be accessed +The `X' attribute is used by the experimental compression patches to +indicate that the raw contents of a compressed file can be accessed directly. It currently may not be set or reset using .BR chattr (1), although it can be displayed by .BR lsattr (1). .PP -The 'Z' attribute is used by the experimental compression patches to +The `Z' attribute is used by the experimental compression patches to indicate a compressed file is dirty. It may not be set or reset using .BR chattr (1), although it can be displayed by @@ -179,7 +194,7 @@ although it can be displayed by was written by Remy Card . It is currently being maintained by Theodore Ts'o . .SH BUGS AND LIMITATIONS -The `c', 's', and `u' attributes are not honored +The `c', `s', and `u' attributes are not honored by the ext2, ext3, and ext4 filesystems as implemented in the current mainline Linux kernels. .PP @@ -191,4 +206,7 @@ The `D' option is only useful on Linux kernel 2.5.19 and later. is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net. .SH SEE ALSO -.BR lsattr (1) +.BR lsattr (1), +.BR btrfs (5), +.BR ext4 (5), +.BR xfs (5). diff --git a/misc/chattr.c b/misc/chattr.c index d5a6a61..f130108 100644 --- a/misc/chattr.c +++ b/misc/chattr.c @@ -83,7 +83,7 @@ static unsigned long sf; static void usage(void) { fprintf(stderr, - _("Usage: %s [-RVf] [-+=aAcCdDeijsSu] [-v version] files...\n"), + _("Usage: %s [-RVf] [-+=aAcCdDeijsStTu] [-v version] files...\n"), program_name); exit(1); }