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Commit fc7f99cf authored by Linus Torvalds's avatar Linus Torvalds
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (205 commits)
  ceph: update for write_inode API change
  ceph: reset osd after relevant messages timed out
  ceph: fix flush_dirty_caps race with caps migration
  ceph: include migrating caps in issued set
  ceph: fix osdmap decoding when pools include (removed) snaps
  ceph: return EBADF if waiting for caps on closed file
  ceph: set osd request message front length correctly
  ceph: reset front len on return to msgpool; BUG on mismatched front iov
  ceph: fix snaptrace decoding on cap migration between mds
  ceph: use single osd op reply msg
  ceph: reset bits on connection close
  ceph: remove bogus mds forward warning
  ceph: remove fragile __map_osds optimization
  ceph: fix connection fault STANDBY check
  ceph: invalidate_authorizer without con->mutex held
  ceph: don't clobber write return value when using O_SYNC
  ceph: fix client_request_forward decoding
  ceph: drop messages on unregistered mds sessions; cleanup
  ceph: fix comments, locking in destroy_inode
  ceph: move dereference after NULL test
  ...

Fix trivial conflicts in Documentation/ioctl/ioctl-number.txt
parents 0a492fde f1a3d572
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Ceph Distributed File System
============================

Ceph is a distributed network file system designed to provide good
performance, reliability, and scalability.

Basic features include:

 * POSIX semantics
 * Seamless scaling from 1 to many thousands of nodes
 * High availability and reliability.  No single points of failure.
 * N-way replication of data across storage nodes
 * Fast recovery from node failures
 * Automatic rebalancing of data on node addition/removal
 * Easy deployment: most FS components are userspace daemons

Also,
 * Flexible snapshots (on any directory)
 * Recursive accounting (nested files, directories, bytes)

In contrast to cluster filesystems like GFS, OCFS2, and GPFS that rely
on symmetric access by all clients to shared block devices, Ceph
separates data and metadata management into independent server
clusters, similar to Lustre.  Unlike Lustre, however, metadata and
storage nodes run entirely as user space daemons.  Storage nodes
utilize btrfs to store data objects, leveraging its advanced features
(checksumming, metadata replication, etc.).  File data is striped
across storage nodes in large chunks to distribute workload and
facilitate high throughputs.  When storage nodes fail, data is
re-replicated in a distributed fashion by the storage nodes themselves
(with some minimal coordination from a cluster monitor), making the
system extremely efficient and scalable.

Metadata servers effectively form a large, consistent, distributed
in-memory cache above the file namespace that is extremely scalable,
dynamically redistributes metadata in response to workload changes,
and can tolerate arbitrary (well, non-Byzantine) node failures.  The
metadata server takes a somewhat unconventional approach to metadata
storage to significantly improve performance for common workloads.  In
particular, inodes with only a single link are embedded in
directories, allowing entire directories of dentries and inodes to be
loaded into its cache with a single I/O operation.  The contents of
extremely large directories can be fragmented and managed by
independent metadata servers, allowing scalable concurrent access.

The system offers automatic data rebalancing/migration when scaling
from a small cluster of just a few nodes to many hundreds, without
requiring an administrator carve the data set into static volumes or
go through the tedious process of migrating data between servers.
When the file system approaches full, new nodes can be easily added
and things will "just work."

Ceph includes flexible snapshot mechanism that allows a user to create
a snapshot on any subdirectory (and its nested contents) in the
system.  Snapshot creation and deletion are as simple as 'mkdir
.snap/foo' and 'rmdir .snap/foo'.

Ceph also provides some recursive accounting on directories for nested
files and bytes.  That is, a 'getfattr -d foo' on any directory in the
system will reveal the total number of nested regular files and
subdirectories, and a summation of all nested file sizes.  This makes
the identification of large disk space consumers relatively quick, as
no 'du' or similar recursive scan of the file system is required.


Mount Syntax
============

The basic mount syntax is:

 # mount -t ceph monip[:port][,monip2[:port]...]:/[subdir] mnt

You only need to specify a single monitor, as the client will get the
full list when it connects.  (However, if the monitor you specify
happens to be down, the mount won't succeed.)  The port can be left
off if the monitor is using the default.  So if the monitor is at
1.2.3.4,

 # mount -t ceph 1.2.3.4:/ /mnt/ceph

is sufficient.  If /sbin/mount.ceph is installed, a hostname can be
used instead of an IP address.



Mount Options
=============

  ip=A.B.C.D[:N]
	Specify the IP and/or port the client should bind to locally.
	There is normally not much reason to do this.  If the IP is not
	specified, the client's IP address is determined by looking at the
	address it's connection to the monitor originates from.

  wsize=X
	Specify the maximum write size in bytes.  By default there is no
	maximu.  Ceph will normally size writes based on the file stripe
	size.

  rsize=X
	Specify the maximum readahead.

  mount_timeout=X
	Specify the timeout value for mount (in seconds), in the case
	of a non-responsive Ceph file system.  The default is 30
	seconds.

  rbytes
	When stat() is called on a directory, set st_size to 'rbytes',
	the summation of file sizes over all files nested beneath that
	directory.  This is the default.

  norbytes
	When stat() is called on a directory, set st_size to the
	number of entries in that directory.

  nocrc
	Disable CRC32C calculation for data writes.  If set, the OSD
	must rely on TCP's error correction to detect data corruption
	in the data payload.

  noasyncreaddir
	Disable client's use its local cache to satisfy	readdir
	requests.  (This does not change correctness; the client uses
	cached metadata only when a lease or capability ensures it is
	valid.)


More Information
================

For more information on Ceph, see the home page at
	http://ceph.newdream.net/

The Linux kernel client source tree is available at
	git://ceph.newdream.net/linux-ceph-client.git

and the source for the full system is at
	git://ceph.newdream.net/ceph.git
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@@ -291,6 +291,7 @@ Code Seq#(hex) Include File Comments
0x92	00-0F	drivers/usb/mon/mon_bin.c
0x93	60-7F	linux/auto_fs.h
0x94	all	fs/btrfs/ioctl.h
0x97	00-7F	fs/ceph/ioctl.h		Ceph file system
0x99	00-0F				537-Addinboard driver
					<mailto:buk@buks.ipn.de>
0xA0	all	linux/sdp/sdp.h		Industrial Device Project
+9 −0
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@@ -1441,6 +1441,15 @@ F: arch/powerpc/include/asm/spu*.h
F:	arch/powerpc/oprofile/*cell*
F:	arch/powerpc/platforms/cell/

CEPH DISTRIBUTED FILE SYSTEM CLIENT
M:	Sage Weil <sage@newdream.net>
L:	ceph-devel@lists.sourceforge.net
W:	http://ceph.newdream.net/
T:	git git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
S:	Supported
F:	Documentation/filesystems/ceph.txt
F:	fs/ceph

CERTIFIED WIRELESS USB (WUSB) SUBSYSTEM:
M:	David Vrabel <david.vrabel@csr.com>
L:	linux-usb@vger.kernel.org
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@@ -235,6 +235,7 @@ config NFS_COMMON

source "net/sunrpc/Kconfig"
source "fs/smbfs/Kconfig"
source "fs/ceph/Kconfig"
source "fs/cifs/Kconfig"
source "fs/ncpfs/Kconfig"
source "fs/coda/Kconfig"
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@@ -125,3 +125,4 @@ obj-$(CONFIG_OCFS2_FS) += ocfs2/
obj-$(CONFIG_BTRFS_FS)		+= btrfs/
obj-$(CONFIG_GFS2_FS)           += gfs2/
obj-$(CONFIG_EXOFS_FS)          += exofs/
obj-$(CONFIG_CEPH_FS)		+= ceph/
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