summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorIngo Molnar <mingo@elte.hu>2008-10-12 15:05:39 +0200
committerIngo Molnar <mingo@elte.hu>2008-10-12 15:05:39 +0200
commita9b9e81c915e4a57ac3b21d1a7fa7ff184639780 (patch)
tree98304395fbb5b9c74fca35b196cd414c1949f280 /Documentation
parenta8b71a2810386a5ac8f43d2095fe3355f0d8db37 (diff)
parentfd048088306656824958e7783ffcee27e241b361 (diff)
Merge branch 'linus' into x86/memory-corruption-check
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/00-INDEX2
-rw-r--r--Documentation/ABI/testing/sysfs-gpio26
-rw-r--r--Documentation/DMA-API.txt2
-rw-r--r--Documentation/DMA-mapping.txt2
-rw-r--r--Documentation/DocBook/kernel-api.tmpl5
-rw-r--r--Documentation/DocBook/mac80211.tmpl12
-rw-r--r--Documentation/HOWTO3
-rw-r--r--Documentation/RCU/checklist.txt2
-rw-r--r--Documentation/RCU/rcuref.txt16
-rw-r--r--Documentation/RCU/whatisRCU.txt2
-rw-r--r--Documentation/SELinux.txt27
-rw-r--r--Documentation/SubmitChecklist2
-rw-r--r--Documentation/block/deadline-iosched.txt14
-rw-r--r--Documentation/cdrom/ide-cd3
-rw-r--r--Documentation/cpu-freq/index.txt10
-rw-r--r--Documentation/cpusets.txt18
-rw-r--r--Documentation/feature-removal-schedule.txt29
-rw-r--r--Documentation/filesystems/ext4.txt14
-rw-r--r--Documentation/filesystems/fiemap.txt228
-rw-r--r--Documentation/filesystems/proc.txt69
-rw-r--r--Documentation/hwmon/adt747318
-rw-r--r--Documentation/hwmon/sysfs-interface12
-rw-r--r--Documentation/ioctl/cdrom.txt4
-rw-r--r--Documentation/kernel-doc-nano-HOWTO.txt4
-rw-r--r--Documentation/kernel-parameters.txt27
-rw-r--r--Documentation/networking/LICENSE.qlge46
-rw-r--r--Documentation/networking/can.txt44
-rw-r--r--Documentation/networking/multiqueue.txt54
-rw-r--r--Documentation/networking/phonet.txt175
-rw-r--r--Documentation/networking/regulatory.txt194
-rw-r--r--Documentation/networking/tproxy.txt85
-rw-r--r--Documentation/rfkill.txt32
-rw-r--r--Documentation/s390/CommonIO11
-rw-r--r--Documentation/scheduler/sched-design-CFS.txt395
-rw-r--r--Documentation/scsi/scsi_fc_transport.txt36
-rw-r--r--Documentation/sound/alsa/ALSA-Configuration.txt62
-rw-r--r--Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl62
-rw-r--r--Documentation/sound/alsa/soc/dapm.txt12
-rw-r--r--Documentation/sysctl/kernel.txt7
-rw-r--r--Documentation/usb/anchors.txt12
-rw-r--r--Documentation/video4linux/CARDLIST.em28xx2
-rw-r--r--Documentation/video4linux/gspca.txt1
-rw-r--r--Documentation/x86/00-INDEX4
-rw-r--r--Documentation/x86/boot.txt (renamed from Documentation/x86/i386/boot.txt)2
-rw-r--r--Documentation/x86/mtrr.txt (renamed from Documentation/mtrr.txt)4
-rw-r--r--Documentation/x86/pat.txt54
-rw-r--r--Documentation/x86/usb-legacy-support.txt (renamed from Documentation/x86/i386/usb-legacy-support.txt)0
-rw-r--r--Documentation/x86/x86_64/boot-options.txt4
-rw-r--r--Documentation/x86/zero-page.txt (renamed from Documentation/x86/i386/zero-page.txt)0
49 files changed, 1515 insertions, 334 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 5b5aba404aac..73060819ed99 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -251,8 +251,6 @@ mono.txt
- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
moxa-smartio
- file with info on installing/using Moxa multiport serial driver.
-mtrr.txt
- - how to use PPro Memory Type Range Registers to increase performance.
mutex-design.txt
- info on the generic mutex subsystem.
namespaces/
diff --git a/Documentation/ABI/testing/sysfs-gpio b/Documentation/ABI/testing/sysfs-gpio
new file mode 100644
index 000000000000..8aab8092ad35
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-gpio
@@ -0,0 +1,26 @@
+What: /sys/class/gpio/
+Date: July 2008
+KernelVersion: 2.6.27
+Contact: David Brownell <dbrownell@users.sourceforge.net>
+Description:
+
+ As a Kconfig option, individual GPIO signals may be accessed from
+ userspace. GPIOs are only made available to userspace by an explicit
+ "export" operation. If a given GPIO is not claimed for use by
+ kernel code, it may be exported by userspace (and unexported later).
+ Kernel code may export it for complete or partial access.
+
+ GPIOs are identified as they are inside the kernel, using integers in
+ the range 0..INT_MAX. See Documentation/gpio.txt for more information.
+
+ /sys/class/gpio
+ /export ... asks the kernel to export a GPIO to userspace
+ /unexport ... to return a GPIO to the kernel
+ /gpioN ... for each exported GPIO #N
+ /value ... always readable, writes fail for input GPIOs
+ /direction ... r/w as: in, out (default low); write: high, low
+ /gpiochipN ... for each gpiochip; #N is its first GPIO
+ /base ... (r/o) same as N
+ /label ... (r/o) descriptive, not necessarily unique
+ /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1)
+
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index d8b63d164e41..b8e86460046e 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -337,7 +337,7 @@ With scatterlists, you use the resulting mapping like this:
int i, count = dma_map_sg(dev, sglist, nents, direction);
struct scatterlist *sg;
- for (i = 0, sg = sglist; i < count; i++, sg++) {
+ for_each_sg(sglist, sg, count, i) {
hw_address[i] = sg_dma_address(sg);
hw_len[i] = sg_dma_len(sg);
}
diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt
index b463ecd0c7ce..c74fec8c2351 100644
--- a/Documentation/DMA-mapping.txt
+++ b/Documentation/DMA-mapping.txt
@@ -740,7 +740,7 @@ failure can be determined by:
dma_addr_t dma_handle;
dma_handle = pci_map_single(pdev, addr, size, direction);
- if (pci_dma_mapping_error(dma_handle)) {
+ if (pci_dma_mapping_error(pdev, dma_handle)) {
/*
* reduce current DMA mapping usage,
* delay and try again later or
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index b7b1482f6e04..9d0058e788e5 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -283,6 +283,7 @@ X!Earch/x86/kernel/mca_32.c
<chapter id="security">
<title>Security Framework</title>
!Isecurity/security.c
+!Esecurity/inode.c
</chapter>
<chapter id="audit">
@@ -364,6 +365,10 @@ X!Edrivers/pnp/system.c
!Eblock/blk-barrier.c
!Eblock/blk-tag.c
!Iblock/blk-tag.c
+!Eblock/blk-integrity.c
+!Iblock/blktrace.c
+!Iblock/genhd.c
+!Eblock/genhd.c
</chapter>
<chapter id="chrdev">
diff --git a/Documentation/DocBook/mac80211.tmpl b/Documentation/DocBook/mac80211.tmpl
index b651e0a4b1c0..77c3c202991b 100644
--- a/Documentation/DocBook/mac80211.tmpl
+++ b/Documentation/DocBook/mac80211.tmpl
@@ -145,7 +145,6 @@ usage should require reading the full document.
this though and the recommendation to allow only a single
interface in STA mode at first!
</para>
-!Finclude/net/mac80211.h ieee80211_if_types
!Finclude/net/mac80211.h ieee80211_if_init_conf
!Finclude/net/mac80211.h ieee80211_if_conf
</chapter>
@@ -177,8 +176,7 @@ usage should require reading the full document.
<title>functions/definitions</title>
!Finclude/net/mac80211.h ieee80211_rx_status
!Finclude/net/mac80211.h mac80211_rx_flags
-!Finclude/net/mac80211.h ieee80211_tx_control
-!Finclude/net/mac80211.h ieee80211_tx_status_flags
+!Finclude/net/mac80211.h ieee80211_tx_info
!Finclude/net/mac80211.h ieee80211_rx
!Finclude/net/mac80211.h ieee80211_rx_irqsafe
!Finclude/net/mac80211.h ieee80211_tx_status
@@ -189,12 +187,11 @@ usage should require reading the full document.
!Finclude/net/mac80211.h ieee80211_ctstoself_duration
!Finclude/net/mac80211.h ieee80211_generic_frame_duration
!Finclude/net/mac80211.h ieee80211_get_hdrlen_from_skb
-!Finclude/net/mac80211.h ieee80211_get_hdrlen
+!Finclude/net/mac80211.h ieee80211_hdrlen
!Finclude/net/mac80211.h ieee80211_wake_queue
!Finclude/net/mac80211.h ieee80211_stop_queue
-!Finclude/net/mac80211.h ieee80211_start_queues
-!Finclude/net/mac80211.h ieee80211_stop_queues
!Finclude/net/mac80211.h ieee80211_wake_queues
+!Finclude/net/mac80211.h ieee80211_stop_queues
</sect1>
</chapter>
@@ -230,8 +227,7 @@ usage should require reading the full document.
<title>Multiple queues and QoS support</title>
<para>TBD</para>
!Finclude/net/mac80211.h ieee80211_tx_queue_params
-!Finclude/net/mac80211.h ieee80211_tx_queue_stats_data
-!Finclude/net/mac80211.h ieee80211_tx_queue
+!Finclude/net/mac80211.h ieee80211_tx_queue_stats
</chapter>
<chapter id="AP">
diff --git a/Documentation/HOWTO b/Documentation/HOWTO
index c2371c5a98f9..48a3955f05fc 100644
--- a/Documentation/HOWTO
+++ b/Documentation/HOWTO
@@ -77,7 +77,8 @@ documentation files are also added which explain how to use the feature.
When a kernel change causes the interface that the kernel exposes to
userspace to change, it is recommended that you send the information or
a patch to the manual pages explaining the change to the manual pages
-maintainer at mtk.manpages@gmail.com.
+maintainer at mtk.manpages@gmail.com, and CC the list
+linux-api@vger.kernel.org.
Here is a list of files that are in the kernel source tree that are
required reading:
diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt
index cf5562cbe356..6e253407b3dc 100644
--- a/Documentation/RCU/checklist.txt
+++ b/Documentation/RCU/checklist.txt
@@ -210,7 +210,7 @@ over a rather long period of time, but improvements are always welcome!
number of updates per grace period.
9. All RCU list-traversal primitives, which include
- rcu_dereference(), list_for_each_rcu(), list_for_each_entry_rcu(),
+ rcu_dereference(), list_for_each_entry_rcu(),
list_for_each_continue_rcu(), and list_for_each_safe_rcu(),
must be either within an RCU read-side critical section or
must be protected by appropriate update-side locks. RCU
diff --git a/Documentation/RCU/rcuref.txt b/Documentation/RCU/rcuref.txt
index 451de2ad8329..4202ad093130 100644
--- a/Documentation/RCU/rcuref.txt
+++ b/Documentation/RCU/rcuref.txt
@@ -29,9 +29,9 @@ release_referenced() delete()
}
If this list/array is made lock free using RCU as in changing the
-write_lock() in add() and delete() to spin_lock and changing read_lock
-in search_and_reference to rcu_read_lock(), the atomic_get in
-search_and_reference could potentially hold reference to an element which
+write_lock() in add() and delete() to spin_lock() and changing read_lock()
+in search_and_reference() to rcu_read_lock(), the atomic_inc() in
+search_and_reference() could potentially hold reference to an element which
has already been deleted from the list/array. Use atomic_inc_not_zero()
in this scenario as follows:
@@ -40,20 +40,20 @@ add() search_and_reference()
{ {
alloc_object rcu_read_lock();
... search_for_element
- atomic_set(&el->rc, 1); if (atomic_inc_not_zero(&el->rc)) {
- write_lock(&list_lock); rcu_read_unlock();
+ atomic_set(&el->rc, 1); if (!atomic_inc_not_zero(&el->rc)) {
+ spin_lock(&list_lock); rcu_read_unlock();
return FAIL;
add_element }
... ...
- write_unlock(&list_lock); rcu_read_unlock();
+ spin_unlock(&list_lock); rcu_read_unlock();
} }
3. 4.
release_referenced() delete()
{ {
- ... write_lock(&list_lock);
+ ... spin_lock(&list_lock);
if (atomic_dec_and_test(&el->rc)) ...
call_rcu(&el->head, el_free); delete_element
- ... write_unlock(&list_lock);
+ ... spin_unlock(&list_lock);
} ...
if (atomic_dec_and_test(&el->rc))
call_rcu(&el->head, el_free);
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index e04d643a9f57..96170824a717 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -786,8 +786,6 @@ RCU pointer/list traversal:
list_for_each_entry_rcu
hlist_for_each_entry_rcu
- list_for_each_rcu (to be deprecated in favor of
- list_for_each_entry_rcu)
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
diff --git a/Documentation/SELinux.txt b/Documentation/SELinux.txt
new file mode 100644
index 000000000000..07eae00f3314
--- /dev/null
+++ b/Documentation/SELinux.txt
@@ -0,0 +1,27 @@
+If you want to use SELinux, chances are you will want
+to use the distro-provided policies, or install the
+latest reference policy release from
+ http://oss.tresys.com/projects/refpolicy
+
+However, if you want to install a dummy policy for
+testing, you can do using 'mdp' provided under
+scripts/selinux. Note that this requires the selinux
+userspace to be installed - in particular you will
+need checkpolicy to compile a kernel, and setfiles and
+fixfiles to label the filesystem.
+
+ 1. Compile the kernel with selinux enabled.
+ 2. Type 'make' to compile mdp.
+ 3. Make sure that you are not running with
+ SELinux enabled and a real policy. If
+ you are, reboot with selinux disabled
+ before continuing.
+ 4. Run install_policy.sh:
+ cd scripts/selinux
+ sh install_policy.sh
+
+Step 4 will create a new dummy policy valid for your
+kernel, with a single selinux user, role, and type.
+It will compile the policy, will set your SELINUXTYPE to
+dummy in /etc/selinux/config, install the compiled policy
+as 'dummy', and relabel your filesystem.
diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist
index da10e0714241..21f0795af20f 100644
--- a/Documentation/SubmitChecklist
+++ b/Documentation/SubmitChecklist
@@ -67,6 +67,8 @@ kernel patches.
19: All new userspace interfaces are documented in Documentation/ABI/.
See Documentation/ABI/README for more information.
+ Patches that change userspace interfaces should be CCed to
+ linux-api@vger.kernel.org.
20: Check that it all passes `make headers_check'.
diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt
index c23cab13c3d1..72576769e0f4 100644
--- a/Documentation/block/deadline-iosched.txt
+++ b/Documentation/block/deadline-iosched.txt
@@ -30,12 +30,18 @@ write_expire (in ms)
Similar to read_expire mentioned above, but for writes.
-fifo_batch
+fifo_batch (number of requests)
----------
-When a read request expires its deadline, we must move some requests from
-the sorted io scheduler list to the block device dispatch queue. fifo_batch
-controls how many requests we move.
+Requests are grouped into ``batches'' of a particular data direction (read or
+write) which are serviced in increasing sector order. To limit extra seeking,
+deadline expiries are only checked between batches. fifo_batch controls the
+maximum number of requests per batch.
+
+This parameter tunes the balance between per-request latency and aggregate
+throughput. When low latency is the primary concern, smaller is better (where
+a value of 1 yields first-come first-served behaviour). Increasing fifo_batch
+generally improves throughput, at the cost of latency variation.
writes_starved (number of dispatches)
diff --git a/Documentation/cdrom/ide-cd b/Documentation/cdrom/ide-cd
index 91c0dcc6fa5c..2c558cd6c1ef 100644
--- a/Documentation/cdrom/ide-cd
+++ b/Documentation/cdrom/ide-cd
@@ -145,8 +145,7 @@ useful for reading photocds.
To play an audio CD, you should first unmount and remove any data
CDROM. Any of the CDROM player programs should then work (workman,
-workbone, cdplayer, etc.). Lacking anything else, you could use the
-cdtester program in Documentation/cdrom/sbpcd.
+workbone, cdplayer, etc.).
On a few drives, you can read digital audio directly using a program
such as cdda2wav. The only types of drive which I've heard support
diff --git a/Documentation/cpu-freq/index.txt b/Documentation/cpu-freq/index.txt
index ffdb5323df37..3d0b915035b9 100644
--- a/Documentation/cpu-freq/index.txt
+++ b/Documentation/cpu-freq/index.txt
@@ -35,11 +35,9 @@ Mailing List
------------
There is a CPU frequency changing CVS commit and general list where
you can report bugs, problems or submit patches. To post a message,
-send an email to cpufreq@lists.linux.org.uk, to subscribe go to
-http://lists.linux.org.uk/mailman/listinfo/cpufreq. Previous post to the
-mailing list are available to subscribers at
-http://lists.linux.org.uk/mailman/private/cpufreq/.
-
+send an email to cpufreq@vger.kernel.org, to subscribe go to
+http://vger.kernel.org/vger-lists.html#cpufreq and follow the
+instructions there.
Links
-----
@@ -50,7 +48,7 @@ how to access the CVS repository:
* http://cvs.arm.linux.org.uk/
the CPUFreq Mailing list:
-* http://lists.linux.org.uk/mailman/listinfo/cpufreq
+* http://vger.kernel.org/vger-lists.html#cpufreq
Clock and voltage scaling for the SA-1100:
* http://www.lartmaker.nl/projects/scaling
diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index 1f5a924d1e56..47e568a9370a 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -635,14 +635,16 @@ prior 'mems' setting, will not be moved.
There is an exception to the above. If hotplug functionality is used
to remove all the CPUs that are currently assigned to a cpuset,
-then the kernel will automatically update the cpus_allowed of all
-tasks attached to CPUs in that cpuset to allow all CPUs. When memory
-hotplug functionality for removing Memory Nodes is available, a
-similar exception is expected to apply there as well. In general,
-the kernel prefers to violate cpuset placement, over starving a task
-that has had all its allowed CPUs or Memory Nodes taken offline. User
-code should reconfigure cpusets to only refer to online CPUs and Memory
-Nodes when using hotplug to add or remove such resources.
+then all the tasks in that cpuset will be moved to the nearest ancestor
+with non-empty cpus. But the moving of some (or all) tasks might fail if
+cpuset is bound with another cgroup subsystem which has some restrictions
+on task attaching. In this failing case, those tasks will stay
+in the original cpuset, and the kernel will automatically update
+their cpus_allowed to allow all online CPUs. When memory hotplug
+functionality for removing Memory Nodes is available, a similar exception
+is expected to apply there as well. In general, the kernel prefers to
+violate cpuset placement, over starving a task that has had all
+its allowed CPUs or Memory Nodes taken offline.
There is a second exception to the above. GFP_ATOMIC requests are
kernel internal allocations that must be satisfied, immediately.
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index eb1a47b97427..3d2d0c29f027 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -6,6 +6,24 @@ be removed from this file.
---------------------------
+What: old static regulatory information and ieee80211_regdom module parameter
+When: 2.6.29
+Why: The old regulatory infrastructure has been replaced with a new one
+ which does not require statically defined regulatory domains. We do
+ not want to keep static regulatory domains in the kernel due to the
+ the dynamic nature of regulatory law and localization. We kept around
+ the old static definitions for the regulatory domains of:
+ * US
+ * JP
+ * EU
+ and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
+ set. We also kept around the ieee80211_regdom module parameter in case
+ some applications were relying on it. Changing regulatory domains
+ can now be done instead by using nl80211, as is done with iw.
+Who: Luis R. Rodriguez <lrodriguez@atheros.com>
+
+---------------------------
+
What: dev->power.power_state
When: July 2007
Why: Broken design for runtime control over driver power states, confusing
@@ -232,6 +250,9 @@ What (Why):
- xt_mark match revision 0
(superseded by xt_mark match revision 1)
+ - xt_recent: the old ipt_recent proc dir
+ (superseded by /proc/net/xt_recent)
+
When: January 2009 or Linux 2.7.0, whichever comes first
Why: Superseded by newer revisions or modules
Who: Jan Engelhardt <jengelh@computergmbh.de>
@@ -322,3 +343,11 @@ Why: Accounting can now be enabled/disabled without kernel recompilation.
controlled by a kernel/module/sysfs/sysctl parameter.
Who: Krzysztof Piotr Oledzki <ole@ans.pl>
+---------------------------
+
+What: ide-scsi (BLK_DEV_IDESCSI)
+When: 2.6.29
+Why: The 2.6 kernel supports direct writing to ide CD drives, which
+ eliminates the need for ide-scsi. The new method is more
+ efficient in every way.
+Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 0d5394920a31..74484e696405 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -32,9 +32,9 @@ Mailing list: linux-ext4@vger.kernel.org
you will need to merge your changes with the version from e2fsprogs
1.41.x.
- - Create a new filesystem using the ext4dev filesystem type:
+ - Create a new filesystem using the ext4 filesystem type:
- # mke2fs -t ext4dev /dev/hda1
+ # mke2fs -t ext4 /dev/hda1
Or configure an existing ext3 filesystem to support extents and set
the test_fs flag to indicate that it's ok for an in-development
@@ -47,13 +47,13 @@ Mailing list: linux-ext4@vger.kernel.org
# tune2fs -I 256 /dev/hda1
- (Note: we currently do not have tools to convert an ext4dev
+ (Note: we currently do not have tools to convert an ext4
filesystem back to ext3; so please do not do try this on production
filesystems.)
- Mounting:
- # mount -t ext4dev /dev/hda1 /wherever
+ # mount -t ext4 /dev/hda1 /wherever
- When comparing performance with other filesystems, remember that
ext3/4 by default offers higher data integrity guarantees than most.
@@ -177,6 +177,11 @@ barrier=<0|1(*)> This enables/disables the use of write barriers in
your disks are battery-backed in one way or another,
disabling barriers may safely improve performance.
+inode_readahead=n This tuning parameter controls the maximum
+ number of inode table blocks that ext4's inode
+ table readahead algorithm will pre-read into
+ the buffer cache. The default value is 32 blocks.
+
orlov (*) This enables the new Orlov block allocator. It is
enabled by default.
@@ -252,6 +257,7 @@ stripe=n Number of filesystem blocks that mballoc will try
delalloc (*) Deferring block allocation until write-out time.
nodelalloc Disable delayed allocation. Blocks are allocation
when data is copied from user to page cache.
+
Data Mode
=========
There are 3 different data modes:
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt
new file mode 100644
index 000000000000..1e3defcfe50b
--- /dev/null
+++ b/Documentation/filesystems/fiemap.txt
@@ -0,0 +1,228 @@
+============
+Fiemap Ioctl
+============
+
+The fiemap ioctl is an efficient method for userspace to get file
+extent mappings. Instead of block-by-block mapping (such as bmap), fiemap
+returns a list of extents.
+
+
+Request Basics
+--------------
+
+A fiemap request is encoded within struct fiemap:
+
+struct fiemap {
+ __u64 fm_start; /* logical offset (inclusive) at
+ * which to start mapping (in) */
+ __u64 fm_length; /* logical length of mapping which
+ * userspace cares about (in) */
+ __u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
+ __u32 fm_mapped_extents; /* number of extents that were
+ * mapped (out) */
+ __u32 fm_extent_count; /* size of fm_extents array (in) */
+ __u32 fm_reserved;
+ struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
+};
+
+
+fm_start, and fm_length specify the logical range within the file
+which the process would like mappings for. Extents returned mirror
+those on disk - that is, the logical offset of the 1st returned extent
+may start before fm_start, and the range covered by the last returned
+extent may end after fm_length. All offsets and lengths are in bytes.
+
+Certain flags to modify the way in which mappings are looked up can be
+set in fm_flags. If the kernel doesn't understand some particular
+flags, it will return EBADR and the contents of fm_flags will contain
+the set of flags which caused the error. If the kernel is compatible
+with all flags passed, the contents of fm_flags will be unmodified.
+It is up to userspace to determine whether rejection of a particular
+flag is fatal to it's operation. This scheme is intended to allow the
+fiemap interface to grow in the future but without losing
+compatibilit