commit 272258e1dffe8afb6c9d0b0ba5edc119dbf9f52a
Author: Eric Sandeen <sandeen@redhat.com>
Date: Fri Jul 4 23:03:14 2014 -0400
e2fsprogs: revise and extend chattr(1) and chattr usage()
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 <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
diff --git a/misc/chattr.1.in b/misc/chattr.1.in
index ce426e8..23b6938 100644
--- a/misc/chattr.1.in
+++ b/misc/chattr.1.in
@@ -21,11 +21,11 @@ changes the file attributes on a Linux file system.
.PP
The format of a symbolic mode is +-=[aAcCdDeijsStTu].
.PP
-The operator `+' causes the selected attributes to be added to the
-existing attributes of the files; `-' causes them to be removed; and
-`=' causes them to be the only attributes that the files have.
+The operator '+' causes the selected attributes to be added to the
+existing attributes of the files; '-' causes them to be removed; and
+'=' causes them to be the only attributes that the files have.
.PP
-The letters `aAcCdDeijsStTu' select the new attributes for the files:
+The letters 'aAcCdDeijsStTu' select the new attributes for the files:
append only (a),
no atime updates (A),
compressed (c),
@@ -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
@@ -63,7 +72,7 @@ Suppress most error messages.
.BI \-v " version"
Set the file's version/generation number.
.SH ATTRIBUTES
-A file with the `a' attribute set can only be open in append mode for writing.
+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
@@ -71,7 +80,7 @@ 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
-A file with the `c' attribute set is automatically compressed on the disk
+A file with the 'c' attribute set is automatically compressed on the disk
by the kernel. A read from this file returns uncompressed data. A write to
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
@@ -86,13 +95,13 @@ 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
-A file with the `d' attribute set is not candidate for backup when the
+A file with the 'd' attribute set is not candidate for backup when the
.BR dump (8)
program is run.
.PP
-When a directory with the `D' attribute set is modified,
+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.
+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 blocks on disk. It may not be removed using
@@ -112,7 +121,7 @@ is (or at one time was) larger than 2TB. It may not be set or reset using
although it can be displayed by
.BR lsattr (1).
.PP
-A file with the `i' attribute cannot be modified: it cannot be deleted or
+A file with the 'i' attribute cannot be modified: it cannot be deleted or
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.
@@ -123,7 +132,7 @@ is being indexed using hashed trees. It may not be set or reset using
although it can be displayed by
.BR lsattr (1).
.PP
-A file with the `j' attribute has all of its data written to the ext3
+A file with the 'j' attribute has all of its data written to the ext3
or ext4 journal before being written to the file itself, if the filesystem
is mounted with the "data=ordered" or "data=writeback" options. When the
filesystem is mounted with the "data=journal" option all file data
@@ -131,13 +140,19 @@ 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
-When a file with the `s' attribute set is deleted, its blocks are zeroed
+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.
.PP
-When a file with the `S' attribute set is modified,
+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.
+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
the end of the file merged with other files (for those filesystems which
@@ -156,13 +171,13 @@ 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.
.PP
-When a file with the `u' attribute set is deleted, its contents are
+When a file with the 'u' attribute set is deleted, its contents are
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
+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
@@ -179,16 +194,19 @@ although it can be displayed by
was written by Remy Card <Remy.Card@linux.org>. It is currently being
maintained by Theodore Ts'o <tytso@alum.mit.edu>.
.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
-The `j' option is only useful if the filesystem is mounted as ext3 or ext4.
+The 'j' option is only useful if the filesystem is mounted as ext3 or ext4.
.PP
-The `D' option is only useful on Linux kernel 2.5.19 and later.
+The 'D' option is only useful on Linux kernel 2.5.19 and later.
.SH AVAILABILITY
.B chattr
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);
}