---

yaml
---
r: 39674
b: refs/heads/master
c: 9d90daf
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e52b29c2a637f6854d71a45646d7283d984a6dad
+refs/heads/master: 9d90dafdb1f0e3c2b69fa8d3fbe99649127c8fa4

trunk/Documentation/filesystems/00-INDEX

@@ -34,6 +34,8 @@ ext2.txt
 	- info, mount options and specifications for the Ext2 filesystem.
 ext3.txt
 	- info, mount options and specifications for the Ext3 filesystem.
+ext4.txt
+	- info, mount options and specifications for the Ext4 filesystem.
 files.txt
 	- info on file management in the Linux kernel.
 fuse.txt

trunk/Documentation/filesystems/ext4.txt

@@ -0,0 +1,236 @@
+
+Ext4 Filesystem
+===============
+
+This is a development version of the ext4 filesystem, an advanced level
+of the ext3 filesystem which incorporates scalability and reliability
+enhancements for supporting large filesystems (64 bit) in keeping with
+increasing disk capacities and state-of-the-art feature requirements.
+
+Mailing list: linux-ext4@vger.kernel.org
+
+
+1. Quick usage instructions:
+===========================
+
+  - Grab updated e2fsprogs from
+    ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs-interim/
+    This is a patchset on top of e2fsprogs-1.39, which can be found at
+    ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/
+
+  - It's still mke2fs -j /dev/hda1
+
+  - mount /dev/hda1 /wherever -t ext4dev
+
+  - To enable extents,
+
+	mount /dev/hda1 /wherever -t ext4dev -o extents
+
+  - The filesystem is compatible with the ext3 driver until you add a file
+    which has extents (ie: `mount -o extents', then create a file).
+
+    NOTE: The "extents" mount flag is temporary.  It will soon go away and
+    extents will be enabled by the "-o extents" flag to mke2fs or tune2fs
+
+  - When comparing performance with other filesystems, remember that
+    ext3/4 by default offers higher data integrity guarantees than most.  So
+    when comparing with a metadata-only journalling filesystem, use `mount -o
+    data=writeback'.  And you might as well use `mount -o nobh' too along
+    with it.  Making the journal larger than the mke2fs default often helps
+    performance with metadata-intensive workloads.
+
+2. Features
+===========
+
+2.1 Currently available
+
+* ability to use filesystems > 16TB
+* extent format reduces metadata overhead (RAM, IO for access, transactions)
+* extent format more robust in face of on-disk corruption due to magics,
+* internal redunancy in tree
+
+2.1 Previously available, soon to be enabled by default by "mkefs.ext4":
+
+* dir_index and resize inode will be on by default
+* large inodes will be used by default for fast EAs, nsec timestamps, etc
+
+2.2 Candidate features for future inclusion
+
+There are several under discussion, whether they all make it in is
+partly a function of how much time everyone has to work on them:
+
+* improved file allocation (multi-block alloc, delayed alloc; basically done)
+* fix 32000 subdirectory limit (patch exists, needs some e2fsck work)
+* nsec timestamps for mtime, atime, ctime, create time (patch exists,
+  needs some e2fsck work)
+* inode version field on disk (NFSv4, Lustre; prototype exists)
+* reduced mke2fs/e2fsck time via uninitialized groups (prototype exists)
+* journal checksumming for robustness, performance (prototype exists)
+* persistent file preallocation (e.g for streaming media, databases)
+
+Features like metadata checksumming have been discussed and planned for
+a bit but no patches exist yet so I'm not sure they're in the near-term
+roadmap.
+
+The big performance win will come with mballoc and delalloc.  CFS has
+been using mballoc for a few years already with Lustre, and IBM + Bull
+did a lot of benchmarking on it.  The reason it isn't in the first set of
+patches is partly a manageability issue, and partly because it doesn't
+directly affect the on-disk format (outside of much better allocation)
+so it isn't critical to get into the first round of changes.  I believe
+Alex is working on a new set of patches right now.
+
+3. Options
+==========
+
+When mounting an ext4 filesystem, the following option are accepted:
+(*) == default
+
+extents			ext4 will use extents to address file data.  The
+			file system will no longer be mountable by ext3.
+
+journal=update		Update the ext4 file system's journal to the current
+			format.
+
+journal=inum		When a journal already exists, this option is ignored.
+			Otherwise, it specifies the number of the inode which
+			will represent the ext4 file system's journal file.
+
+journal_dev=devnum	When the external journal device's major/minor numbers
+			have changed, this option allows the user to specify
+			the new journal location.  The journal device is
+			identified through its new major/minor numbers encoded
+			in devnum.
+
+noload			Don't load the journal on mounting.
+
+data=journal		All data are committed into the journal prior to being
+			written into the main file system.
+
+data=ordered	(*)	All data are forced directly out to the main file
+			system prior to its metadata being committed to the
+			journal.
+
+data=writeback		Data ordering is not preserved, data may be written
+			into the main file system after its metadata has been
+			committed to the journal.
+
+commit=nrsec	(*)	Ext4 can be told to sync all its data and metadata
+			every 'nrsec' seconds. The default value is 5 seconds.
+			This means that if you lose your power, you will lose
+			as much as the latest 5 seconds of work (your
+			filesystem will not be damaged though, thanks to the
+			journaling).  This default value (or any low value)
+			will hurt performance, but it's good for data-safety.
+			Setting it to 0 will have the same effect as leaving
+			it at the default (5 seconds).
+			Setting it to very large values will improve
+			performance.
+
+barrier=1		This enables/disables barriers.  barrier=0 disables
+			it, barrier=1 enables it.
+
+orlov		(*)	This enables the new Orlov block allocator. It is
+			enabled by default.
+
+oldalloc		This disables the Orlov block allocator and enables
+			the old block allocator.  Orlov should have better
+			performance - we'd like to get some feedback if it's
+			the contrary for you.
+
+user_xattr		Enables Extended User Attributes.  Additionally, you
+			need to have extended attribute support enabled in the
+			kernel configuration (CONFIG_EXT4_FS_XATTR).  See the
+			attr(5) manual page and http://acl.bestbits.at/ to
+			learn more about extended attributes.
+
+nouser_xattr		Disables Extended User Attributes.
+
+acl			Enables POSIX Access Control Lists support.
+			Additionally, you need to have ACL support enabled in
+			the kernel configuration (CONFIG_EXT4_FS_POSIX_ACL).
+			See the acl(5) manual page and http://acl.bestbits.at/
+			for more information.
+
+noacl			This option disables POSIX Access Control List
+			support.
+
+reservation
+
+noreservation
+
+bsddf		(*)	Make 'df' act like BSD.
+minixdf			Make 'df' act like Minix.
+
+check=none		Don't do extra checking of bitmaps on mount.
+nocheck
+
+debug			Extra debugging information is sent to syslog.
+
+errors=remount-ro(*)	Remount the filesystem read-only on an error.
+errors=continue		Keep going on a filesystem error.
+errors=panic		Panic and halt the machine if an error occurs.
+
+grpid			Give objects the same group ID as their creator.
+bsdgroups
+
+nogrpid		(*)	New objects have the group ID of their creator.
+sysvgroups
+
+resgid=n		The group ID which may use the reserved blocks.
+
+resuid=n		The user ID which may use the reserved blocks.
+
+sb=n			Use alternate superblock at this location.
+
+quota
+noquota
+grpquota
+usrquota
+
+bh		(*)	ext4 associates buffer heads to data pages to
+nobh			(a) cache disk block mapping information
+			(b) link pages into transaction to provide
+			    ordering guarantees.
+			"bh" option forces use of buffer heads.
+			"nobh" option tries to avoid associating buffer
+			heads (supported only for "writeback" mode).
+
+
+Data Mode
+---------
+There are 3 different data modes:
+
+* writeback mode
+In data=writeback mode, ext4 does not journal data at all.  This mode provides
+a similar level of journaling as that of XFS, JFS, and ReiserFS in its default
+mode - metadata journaling.  A crash+recovery can cause incorrect data to
+appear in files which were written shortly before the crash.  This mode will
+typically provide the best ext4 performance.
+
+* ordered mode
+In data=ordered mode, ext4 only officially journals metadata, but it logically
+groups metadata and data blocks into a single unit called a transaction.  When
+it's time to write the new metadata out to disk, the associated data blocks
+are written first.  In general, this mode performs slightly slower than
+writeback but significantly faster than journal mode.
+
+* journal mode
+data=journal mode provides full data and metadata journaling.  All new data is
+written to the journal first, and then to its final location.
+In the event of a crash, the journal can be replayed, bringing both data and
+metadata into a consistent state.  This mode is the slowest except when data
+needs to be read from and written to disk at the same time where it
+outperforms all others modes.
+
+References
+==========
+
+kernel source:	<file:fs/ext4/>
+		<file:fs/jbd2/>
+
+programs:	http://e2fsprogs.sourceforge.net/
+		http://ext2resize.sourceforge.net
+
+useful links:	http://fedoraproject.org/wiki/ext3-devel
+		http://www.bullopensource.org/ext4/

trunk/Documentation/ibm-acpi.txt

@@ -30,9 +30,10 @@ detailed description):
 	- ACPI sounds
 	- temperature sensors
 	- Experimental: embedded controller register dump
-	- Experimental: LCD brightness control
-	- Experimental: volume control
+	- LCD brightness control
+	- Volume control
 	- Experimental: fan speed, fan enable/disable
+	- Experimental: WAN enable and disable
 
 A compatibility table by model and feature is maintained on the web
 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
@@ -52,40 +53,7 @@ Installation
 
 If you are compiling this driver as included in the Linux kernel
 sources, simply enable the CONFIG_ACPI_IBM option (Power Management /
-ACPI / IBM ThinkPad Laptop Extras). The rest of this section describes
-how to install this driver when downloaded from the web site.
-
-First, you need to get a kernel with ACPI support up and running.
-Please refer to http://acpi.sourceforge.net/ for help with this
-step. How successful you will be depends a lot on you ThinkPad model,
-the kernel you are using and any additional patches applied. The
-kernel provided with your distribution may not be good enough. I
-needed to compile a 2.6.7 kernel with the 20040715 ACPI patch to get
-ACPI working reliably on my ThinkPad X40. Old ThinkPad models may not
-be supported at all.
-
-Assuming you have the basic ACPI support working (e.g. you can see the
-/proc/acpi directory), follow the following steps to install this
-driver:
-
-	- unpack the archive:
-
-		tar xzvf ibm-acpi-x.y.tar.gz; cd ibm-acpi-x.y
-
-	- compile the driver:
-
-		make
-
-	- install the module in your kernel modules directory:
-
-		make install
-
-	- load the module:
-
-		modprobe ibm_acpi
-
-After loading the module, check the "dmesg" output for any error messages.
-
+ACPI / IBM ThinkPad Laptop Extras).
 
 Features
 --------
@@ -523,13 +491,8 @@ registers contain the current battery capacity, etc. If you experiment
 with this, do send me your results (including some complete dumps with
 a description of the conditions when they were taken.)
 
-EXPERIMENTAL: LCD brightness control -- /proc/acpi/ibm/brightness
------------------------------------------------------------------
-
-This feature is marked EXPERIMENTAL because the implementation
-directly accesses hardware registers and may not work as expected. USE
-WITH CAUTION! To use this feature, you need to supply the
-experimental=1 parameter when loading the module.
+LCD brightness control -- /proc/acpi/ibm/brightness
+---------------------------------------------------
 
 This feature allows software control of the LCD brightness on ThinkPad
 models which don't have a hardware brightness slider. The available
@@ -542,13 +505,8 @@ commands are:
 The <level> number range is 0 to 7, although not all of them may be
 distinct. The current brightness level is shown in the file.
 
-EXPERIMENTAL: Volume control -- /proc/acpi/ibm/volume
------------------------------------------------------
-
-This feature is marked EXPERIMENTAL because the implementation
-directly accesses hardware registers and may not work as expected. USE
-WITH CAUTION! To use this feature, you need to supply the
-experimental=1 parameter when loading the module.
+Volume control -- /proc/acpi/ibm/volume
+---------------------------------------
 
 This feature allows volume control on ThinkPad models which don't have
 a hardware volume knob. The available commands are:
@@ -611,6 +569,23 @@ with the following command:
 
 	echo 'level <level>' > /proc/acpi/ibm/thermal
 
+EXPERIMENTAL: WAN -- /proc/acpi/ibm/wan
+---------------------------------------
+
+This feature is marked EXPERIMENTAL because the implementation
+directly accesses hardware registers and may not work as expected. USE
+WITH CAUTION! To use this feature, you need to supply the
+experimental=1 parameter when loading the module.
+
+This feature shows the presence and current state of a WAN (Sierra
+Wireless EV-DO) device. If WAN is installed, the following commands can
+be used:
+
+	echo enable > /proc/acpi/ibm/wan
+	echo disable > /proc/acpi/ibm/wan
+
+It was tested on a Lenovo Thinkpad X60. It should probably work on other
+Thinkpad models which come with this module installed.
 
 Multiple Commands, Module Parameters
 ------------------------------------

trunk/Documentation/lockdep-design.txt

@@ -50,10 +50,10 @@ The bit position indicates hardirq, softirq, hardirq-read,
 softirq-read respectively, and the character displayed in each
 indicates:
 
-   '.'	 acquired while irqs enabled
+   '.'  acquired while irqs disabled
    '+'  acquired in irq context
-   '-'  acquired in process context with irqs disabled
-   '?'  read-acquired both with irqs enabled and in irq context
+   '-'  acquired with irqs enabled
+   '?' read acquired in irq context with irqs enabled.
 
 Unused mutexes cannot be part of the cause of an error.
 

trunk/Documentation/sysctl/kernel.txt

@@ -86,7 +86,7 @@ valid for 30 seconds.
 core_pattern:
 
 core_pattern is used to specify a core dumpfile pattern name.
-. max length 64 characters; default value is "core"
+. max length 128 characters; default value is "core"
 . core_pattern is used as a pattern template for the output filename;
   certain string patterns (beginning with '%') are substituted with
   their actual values.
@@ -105,6 +105,9 @@ core_pattern is used to specify a core dumpfile pattern name.
 	%h	hostname
 	%e	executable filename
 	%<OTHER> both are dropped
+. If the first character of the pattern is a '|', the kernel will treat
+  the rest of the pattern as a command to run.  The core dump will be
+  written to the standard input of that program instead of to a file.
 
 ==============================================================