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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-23 04:02:52 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-23 04:02:52 +0200
commitd4c90b1b9fe907da0d310008e5a769b591a14399 (patch)
treed37589ab70ada2778d315a0ad24d6e68c8615af6 /Documentation
parentLinux 3.11-rc2 (diff)
parentMerge branch 'bcache-for-3.11' of git://evilpiepirate.org/~kent/linux-bcache ... (diff)
downloadlinux-d4c90b1b9fe907da0d310008e5a769b591a14399.tar.xz
linux-d4c90b1b9fe907da0d310008e5a769b591a14399.zip
Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block
Pull block IO driver bits from Jens Axboe: "As I mentioned in the core block pull request, due to real life circumstances the driver pull request would be late. Now it looks like -rc2 late... On the plus side, apart form the rsxx update, these are all things that I could argue could go in later in the cycle as they are fixes and not features. So even though things are late, it's not ALL bad. The pull request contains: - Updates to bcache, all bug fixes, from Kent. - A pile of drbd bug fixes (no big features this time!). - xen blk front/back fixes. - rsxx driver updates, some of them deferred form 3.10. So should be well cooked by now" * 'for-3.11/drivers' of git://git.kernel.dk/linux-block: (63 commits) bcache: Allocation kthread fixes bcache: Fix GC_SECTORS_USED() calculation bcache: Journal replay fix bcache: Shutdown fix bcache: Fix a sysfs splat on shutdown bcache: Advertise that flushes are supported bcache: check for allocation failures bcache: Fix a dumb race bcache: Use standard utility code bcache: Update email address bcache: Delete fuzz tester bcache: Document shrinker reserve better bcache: FUA fixes drbd: Allow online change of al-stripes and al-stripe-size drbd: Constants should be UPPERCASE drbd: Ignore the exit code of a fence-peer handler if it returns too late drbd: Fix rcu_read_lock balance on error path drbd: fix error return code in drbd_init() drbd: Do not sleep inside rcu bcache: Refresh usage docs ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-driver-xen-blkback17
-rw-r--r--Documentation/ABI/testing/sysfs-driver-xen-blkfront10
-rw-r--r--Documentation/bcache.txt37
3 files changed, 51 insertions, 13 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback
new file mode 100644
index 000000000000..8bb43b66eb55
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback
@@ -0,0 +1,17 @@
+What: /sys/module/xen_blkback/parameters/max_buffer_pages
+Date: March 2013
+KernelVersion: 3.11
+Contact: Roger Pau Monné <roger.pau@citrix.com>
+Description:
+ Maximum number of free pages to keep in each block
+ backend buffer.
+
+What: /sys/module/xen_blkback/parameters/max_persistent_grants
+Date: March 2013
+KernelVersion: 3.11
+Contact: Roger Pau Monné <roger.pau@citrix.com>
+Description:
+ Maximum number of grants to map persistently in
+ blkback. If the frontend tries to use more than
+ max_persistent_grants, the LRU kicks in and starts
+ removing 5% of max_persistent_grants every 100ms.
diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkfront b/Documentation/ABI/testing/sysfs-driver-xen-blkfront
new file mode 100644
index 000000000000..c0a6cb7eb314
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xen-blkfront
@@ -0,0 +1,10 @@
+What: /sys/module/xen_blkfront/parameters/max
+Date: June 2013
+KernelVersion: 3.11
+Contact: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+ Maximum number of segments that the frontend will negotiate
+ with the backend for indirect descriptors. The default value
+ is 32 - higher value means more potential throughput but more
+ memory usage. The backend picks the minimum of the frontend
+ and its default backend value.
diff --git a/Documentation/bcache.txt b/Documentation/bcache.txt
index c3365f26b2d9..32b6c3189d98 100644
--- a/Documentation/bcache.txt
+++ b/Documentation/bcache.txt
@@ -46,29 +46,33 @@ you format your backing devices and cache device at the same time, you won't
have to manually attach:
make-bcache -B /dev/sda /dev/sdb -C /dev/sdc
-To make bcache devices known to the kernel, echo them to /sys/fs/bcache/register:
+bcache-tools now ships udev rules, and bcache devices are known to the kernel
+immediately. Without udev, you can manually register devices like this:
echo /dev/sdb > /sys/fs/bcache/register
echo /dev/sdc > /sys/fs/bcache/register
-To register your bcache devices automatically, you could add something like
-this to an init script:
+Registering the backing device makes the bcache device show up in /dev; you can
+now format it and use it as normal. But the first time using a new bcache
+device, it'll be running in passthrough mode until you attach it to a cache.
+See the section on attaching.
- echo /dev/sd* > /sys/fs/bcache/register_quiet
+The devices show up as:
-It'll look for bcache superblocks and ignore everything that doesn't have one.
+ /dev/bcache<N>
-Registering the backing device makes the bcache show up in /dev; you can now
-format it and use it as normal. But the first time using a new bcache device,
-it'll be running in passthrough mode until you attach it to a cache. See the
-section on attaching.
+As well as (with udev):
-The devices show up at /dev/bcacheN, and can be controlled via sysfs from
-/sys/block/bcacheN/bcache:
+ /dev/bcache/by-uuid/<uuid>
+ /dev/bcache/by-label/<label>
+
+To get started:
mkfs.ext4 /dev/bcache0
mount /dev/bcache0 /mnt
+You can control bcache devices through sysfs at /sys/block/bcache<N>/bcache .
+
Cache devices are managed as sets; multiple caches per set isn't supported yet
but will allow for mirroring of metadata and dirty data in the future. Your new
cache set shows up as /sys/fs/bcache/<UUID>
@@ -80,11 +84,11 @@ must be attached to your cache set to enable caching. Attaching a backing
device to a cache set is done thusly, with the UUID of the cache set in
/sys/fs/bcache:
- echo <UUID> > /sys/block/bcache0/bcache/attach
+ echo <CSET-UUID> > /sys/block/bcache0/bcache/attach
This only has to be done once. The next time you reboot, just reregister all
your bcache devices. If a backing device has data in a cache somewhere, the
-/dev/bcache# device won't be created until the cache shows up - particularly
+/dev/bcache<N> device won't be created until the cache shows up - particularly
important if you have writeback caching turned on.
If you're booting up and your cache device is gone and never coming back, you
@@ -191,6 +195,9 @@ want for getting the best possible numbers when benchmarking.
SYSFS - BACKING DEVICE:
+Available at /sys/block/<bdev>/bcache, /sys/block/bcache*/bcache and
+(if attached) /sys/fs/bcache/<cset-uuid>/bdev*
+
attach
Echo the UUID of a cache set to this file to enable caching.
@@ -300,6 +307,8 @@ cache_readaheads
SYSFS - CACHE SET:
+Available at /sys/fs/bcache/<cset-uuid>
+
average_key_size
Average data per key in the btree.
@@ -390,6 +399,8 @@ trigger_gc
SYSFS - CACHE DEVICE:
+Available at /sys/block/<cdev>/bcache
+
block_size
Minimum granularity of writes - should match hardware sector size.