Basic state information is available via /sys/kernel/debug/ceph,
including instances of the client, fsids, current monitor, mds and osd
maps, outstanding server requests, and hooks to adjust debug levels.
Signed-off-by: Sage Weil <sage@newdream.net>
A few Ceph ioctls for getting and setting file layout (striping)
parameters, and learning the identity and network address of the OSD a
given region of a file is stored on.
Signed-off-by: Sage Weil <sage@newdream.net>
Basic NFS re-export support is included. This mostly works. However,
Ceph's MDS design precludes the ability to generate a (small)
filehandle that will be valid forever, so this is of limited utility.
Signed-off-by: Sage Weil <sage@newdream.net>
The msgpool is a basic mempool_t-like structure to preallocate
messages we expect to receive over the wire. This ensures we have the
necessary memory preallocated to process replies to requests, or to
process unsolicited messages from various servers.
Signed-off-by: Sage Weil <sage@newdream.net>
A generic message passing library is used to communicate with all
other components in the Ceph file system. The messenger library
provides ordered, reliable delivery of messages between two nodes in
the system.
This implementation is based on TCP.
Signed-off-by: Sage Weil <sage@newdream.net>
Ceph snapshots rely on client cooperation in determining which
operations apply to which snapshots, and appropriately flushing
snapshotted data and metadata back to the OSD and MDS clusters.
Because snapshots apply to subtrees of the file hierarchy and can be
created at any time, there is a fair bit of bookkeeping required to
make this work.
Portions of the hierarchy that belong to the same set of snapshots
are described by a single 'snap realm.' A 'snap context' describes
the set of snapshots that exist for a given file or directory.
Signed-off-by: Sage Weil <sage@newdream.net>
The Ceph metadata servers control client access to inode metadata and
file data by issuing capabilities, granting clients permission to read
and/or write both inode field and file data to OSDs (storage nodes).
Each capability consists of a set of bits indicating which operations
are allowed.
If the client holds a *_SHARED cap, the client has a coherent value
that can be safely read from the cached inode.
In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the client
is allowed to change inode attributes (e.g., file size, mtime), note
its dirty state in the ceph_cap, and asynchronously flush that
metadata change to the MDS.
In the event of a conflicting operation (perhaps by another client),
the MDS will revoke the conflicting client capabilities.
In order for a client to cache an inode, it must hold a capability
with at least one MDS server. When inodes are released, release
notifications are batched and periodically sent en masse to the MDS
cluster to release server state.
Signed-off-by: Sage Weil <sage@newdream.net>
The monitor cluster is responsible for managing cluster membership
and state. The monitor client handles what minimal interaction
the Ceph client has with it: checking for updated versions of the
MDS and OSD maps, getting statfs() information, and unmounting.
Signed-off-by: Sage Weil <sage@newdream.net>
CRUSH is a pseudorandom data distribution function designed to map
inputs onto a dynamic hierarchy of devices, while minimizing the
extent to which inputs are remapped when the devices are added or
removed. It includes some features that are specifically useful for
storage, most notably the ability to map each input onto a set of N
devices that are separated across administrator-defined failure
domains. CRUSH is used to distribute data across the cluster of Ceph
storage nodes.
More information about CRUSH can be found in this paper:
http://www.ssrc.ucsc.edu/Papers/weil-sc06.pdf
Signed-off-by: Sage Weil <sage@newdream.net>
The OSD client is responsible for reading and writing data from/to the
object storage pool. This includes determining where objects are
stored in the cluster, and ensuring that requests are retried or
redirected in the event of a node failure or data migration.
If an OSD does not respond before a timeout expires, keepalive
messages are sent across the lossless, ordered communications channel
to ensure that any break in the TCP is discovered. If the session
does reset, a reconnection is attempted and affected requests are
resent (by the message transport layer).
Signed-off-by: Sage Weil <sage@newdream.net>
The MDS (metadata server) client is responsible for submitting
requests to the MDS cluster and parsing the response. We decide which
MDS to submit each request to based on cached information about the
current partition of the directory hierarchy across the cluster. A
stateful session is opened with each MDS before we submit requests to
it, and a mutex is used to control the ordering of messages within
each session.
An MDS request may generate two responses. The first indicates the
operation was a success and returns any result. A second reply is
sent when the operation commits to disk. Note that locking on the MDS
ensures that the results of updates are visible only to the updating
client before the operation commits. Requests are linked to the
containing directory so that an fsync will wait for them to commit.
If an MDS fails and/or recovers, we resubmit requests as needed. We
also reconnect existing capabilities to a recovering MDS to
reestablish that shared session state. Old dentry leases are
invalidated.
Signed-off-by: Sage Weil <sage@newdream.net>
The ceph address space methods are concerned primarily with managing
the dirty page accounting in the inode, which (among other things)
must keep track of which snapshot context each page was dirtied in,
and ensure that dirty data is written out to the OSDs in snapshort
order.
A writepage() on a page that is not currently writeable due to
snapshot writeback ordering constraints is ignored (it was presumably
called from kswapd).
Signed-off-by: Sage Weil <sage@newdream.net>
File open and close operations, and read and write methods that ensure
we have obtained the proper capabilities from the MDS cluster before
performing IO on a file. We take references on held capabilities for
the duration of the read/write to avoid prematurely releasing them
back to the MDS.
We implement two main paths for read and write: one that is buffered
(and uses generic_aio_{read,write}), and one that is fully synchronous
and blocking (operating either on a __user pointer or, if O_DIRECT,
directly on user pages).
Signed-off-by: Sage Weil <sage@newdream.net>
Directory operations, including lookup, are defined here. We take
advantage of lookup intents when possible. For the most part, we just
need to build the proper requests for the metadata server(s) and
pass things off to the mds_client.
The results of most operations are normally incorporated into the
client's cache when the reply is parsed by ceph_fill_trace().
However, if the MDS replies without a trace (e.g., when retrying an
update after an MDS failure recovery), some operation-specific cleanup
may be needed.
We can validate cached dentries in two ways. A per-dentry lease may
be issued by the MDS, or a per-directory cap may be issued that acts
as a lease on the entire directory. In the latter case, a 'gen' value
is used to determine which dentries belong to the currently leased
directory contents.
We normally prepopulate the dcache and icache with readdir results.
This makes subsequent lookups and getattrs avoid any server
interaction. It also lets us satisfy readdir operation by peeking at
the dcache IFF we hold the per-directory cap/lease, previously
performed a readdir, and haven't dropped any of the resulting
dentries.
Signed-off-by: Sage Weil <sage@newdream.net>
Inode cache and inode operations. We also include routines to
incorporate metadata structures returned by the MDS into the client
cache, and some helpers to deal with file capabilities and metadata
leases. The bulk of that work is done by fill_inode() and
fill_trace().
Signed-off-by: Sage Weil <sage@newdream.net>
struct ceph_buffer is a simple ref-counted buffer. We transparently
choose between kmalloc for small buffers and vmalloc for large ones.
This is currently used only for allocating memory for xattr data.
Signed-off-by: Sage Weil <sage@newdream.net>
We first define constants, types, and prototypes for the kernel client
proper.
A few subsystems are defined separately later: the MDS, OSD, and
monitor clients, and the messaging layer.
Signed-off-by: Sage Weil <sage@newdream.net>
These headers describe the types used to exchange messages between the
Ceph client and various servers. All types are little-endian and
packed. These headers are shared between the kernel and userspace, so
all types are in terms of e.g. __u32.
Additionally, we define a few magic values to identify the current
version of the protocol(s) in use, so that discrepancies to be
detected on mount.
Signed-off-by: Sage Weil <sage@newdream.net>
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code
But leave TTM code alone, something is fishy there with global vm_ops
being used.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: fix locking and list handling code in cifs_open and its helper
[CIFS] Remove build warning
cifs: fix problems with last two commits
[CIFS] Fix build break when keys support turned off
cifs: eliminate cifs_init_private
cifs: convert oplock breaks to use slow_work facility (try #4)
cifs: have cifsFileInfo hold an extra inode reference
cifs: take read lock on GlobalSMBSes_lock in is_valid_oplock_break
cifs: remove cifsInodeInfo.oplockPending flag
cifs: fix oplock request handling in posix codepath
[CIFS] Re-enable Lanman security
Sometimes we only want to write pages from a specific super_block,
so allow that to be passed in.
This fixes a problem with commit 56a131dcf7
causing writeback on all super_blocks on a bdi, where we only really
want to sync a specific sb from writeback_inodes_sb().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The patch to remove cifs_init_private introduced a locking imbalance. It
didn't remove the leftover list addition code and the unlocking in that
function. cifs_new_fileinfo does the list addition now, so there should
be no need to do it outside of that function.
pCifsInode will never be NULL, so we don't need to check for that. This
patch also gets rid of the ugly locking and unlocking across function
calls.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
writeback: writeback_inodes_sb() should use bdi_start_writeback()
writeback: don't delay inodes redirtied by a fast dirtier
writeback: make the super_block pinning more efficient
writeback: don't resort for a single super_block in move_expired_inodes()
writeback: move inodes from one super_block together
writeback: get rid to incorrect references to pdflush in comments
writeback: improve readability of the wb_writeback() continue/break logic
writeback: cleanup writeback_single_inode()
writeback: kupdate writeback shall not stop when more io is possible
writeback: stop background writeback when below background threshold
writeback: balance_dirty_pages() shall write more than dirtied pages
fs: Fix busyloop in wb_writeback()
Debug traces show that in per-bdi writeback, the inode under writeback
almost always get redirtied by a busy dirtier. We used to call
redirty_tail() in this case, which could delay inode for up to 30s.
This is unacceptable because it now happens so frequently for plain cp/dd,
that the accumulated delays could make writeback of big files very slow.
So let's distinguish between data redirty and metadata only redirty.
The first one is caused by a busy dirtier, while the latter one could
happen in XFS, NFS, etc. when they are doing delalloc or updating isize.
The inode being busy dirtied will now be requeued for next io, while
the inode being redirtied by fs will continue to be delayed to avoid
repeated IO.
CC: Jan Kara <jack@suse.cz>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Dave Chinner <david@fromorbit.com>
CC: Chris Mason <chris.mason@oracle.com>
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently we pin the inode->i_sb for every single inode. This
increases cache traffic on sb->s_umount sem. Lets instead
cache the inode sb pin state and keep the super_block pinned
for as long as keep writing out inodes from the same
super_block.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
If we only moved inodes from a single super_block to the temporary
list, there's no point in doing a resort for multiple super_blocks.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
__mark_inode_dirty adds inode to wb dirty list in random order. If a disk has
several partitions, writeback might keep spindle moving between partitions.
To reduce the move, better write big chunk of one partition and then move to
another. Inodes from one fs usually are in one partion, so idealy move indoes
from one fs together should reduce spindle move. This patch tries to address
this. Before per-bdi writeback is added, the behavior is write indoes
from one fs first and then another, so the patch restores previous behavior.
The loop in the patch is a bit ugly, should we add a dirty list for each
superblock in bdi_writeback?
Test in a two partition disk with attached fio script shows about 3% ~ 6%
improvement.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Make the if-else straight in writeback_single_inode().
No behavior change.
Cc: Jan Kara <jack@suse.cz>
Cc: Michael Rubin <mrubin@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Fix the kupdate case, which disregards wbc.more_io and stop writeback
prematurely even when there are more inodes to be synced.
wbc.more_io should always be respected.
Also remove the pages_skipped check. It will set when some page(s) of some
inode(s) cannot be written for now. Such inodes will be delayed for a while.
This variable has nothing to do with whether there are other writeable inodes.
CC: Jan Kara <jack@suse.cz>
CC: Dave Chinner <david@fromorbit.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Treat bdi_start_writeback(0) as a special request to do background write,
and stop such work when we are below the background dirty threshold.
Also simplify the (nr_pages <= 0) checks. Since we already pass in
nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't
need to worry about it being decreased to zero.
Reported-by: Richard Kennedy <richard@rsk.demon.co.uk>
CC: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
If all inodes are under writeback (e.g. in case when there's only one inode
with dirty pages), wb_writeback() with WB_SYNC_NONE work basically degrades
to busylooping until I_SYNC flags of the inode is cleared. Fix the problem by
waiting on I_SYNC flags of an inode on b_more_io list in case we failed to
write anything.
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
...it does the same thing as cifs_fill_fileinfo, but doesn't handle the
flist ordering correctly. Also rename cifs_fill_fileinfo to a more
descriptive name and have it take an open flags arg instead of just a
write_only flag. That makes the logic in the callers a little simpler.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We forget to set nfs_server.protocol in tcp case when old-style binary
options are passed to mount. The thing remains zero and never validated
afterwards. As the result, we hit BUG in fs/nfs/client.c:588.
Breakage has been introduced in NFS: Add nfs_alloc_parsed_mount_data
merged yesterday...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This is the fourth respin of the patch to convert oplock breaks to
use the slow_work facility.
A customer of ours was testing a backport of one of the earlier
patchsets, and hit a "Busy inodes after umount..." problem. An oplock
break job had raced with a umount, and the superblock got torn down and
its memory reused. When the oplock break job tried to dereference the
inode->i_sb, the kernel oopsed.
This patchset has the oplock break job hold an inode and vfsmount
reference until the oplock break completes. With this, there should be
no need to take a tcon reference (the vfsmount implicitly holds one
already).
Currently, when an oplock break comes in there's a chance that the
oplock break job won't occur if the allocation of the oplock_q_entry
fails. There are also some rather nasty races in the allocation and
handling these structs.
Rather than allocating oplock queue entries when an oplock break comes
in, add a few extra fields to the cifsFileInfo struct. Get rid of the
dedicated cifs_oplock_thread as well and queue the oplock break job to
the slow_work thread pool.
This approach also has the advantage that the oplock break jobs can
potentially run in parallel rather than be serialized like they are
today.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (42 commits)
Btrfs: hash the btree inode during fill_super
Btrfs: relocate file extents in clusters
Btrfs: don't rename file into dummy directory
Btrfs: check size of inode backref before adding hardlink
Btrfs: fix releasepage to avoid unlocking extents we haven't locked
Btrfs: Fix test_range_bit for whole file extents
Btrfs: fix errors handling cached state in set/clear_extent_bit
Btrfs: fix early enospc during balancing
Btrfs: deal with NULL space info
Btrfs: account for space used by the super mirrors
Btrfs: fix extent entry threshold calculation
Btrfs: remove dead code
Btrfs: fix bitmap size tracking
Btrfs: don't keep retrying a block group if we fail to allocate a cluster
Btrfs: make balance code choose more wisely when relocating
Btrfs: fix arithmetic error in clone ioctl
Btrfs: add snapshot/subvolume destroy ioctl
Btrfs: change how subvolumes are organized
Btrfs: do not reuse objectid of deleted snapshot/subvol
Btrfs: speed up snapshot dropping
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
truncate: use new helpers
truncate: new helpers
fs: fix overflow in sys_mount() for in-kernel calls
fs: Make unload_nls() NULL pointer safe
freeze_bdev: grab active reference to frozen superblocks
freeze_bdev: kill bd_mount_sem
exofs: remove BKL from super operations
fs/romfs: correct error-handling code
vfs: seq_file: add helpers for data filling
vfs: remove redundant position check in do_sendfile
vfs: change sb->s_maxbytes to a loff_t
vfs: explicitly cast s_maxbytes in fiemap_check_ranges
libfs: return error code on failed attr set
seq_file: return a negative error code when seq_path_root() fails.
vfs: optimize touch_time() too
vfs: optimization for touch_atime()
vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it
fs/inode.c: add dev-id and inode number for debugging in init_special_inode()
libfs: make simple_read_from_buffer conventional
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
HWPOISON: Enable error_remove_page on btrfs
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
HWPOISON: Add madvise() based injector for hardware poisoned pages v4
HWPOISON: Enable error_remove_page for NFS
HWPOISON: Enable .remove_error_page for migration aware file systems
HWPOISON: The high level memory error handler in the VM v7
HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
HWPOISON: shmem: call set_page_dirty() with locked page
HWPOISON: Define a new error_remove_page address space op for async truncation
HWPOISON: Add invalidate_inode_page
HWPOISON: Refactor truncate to allow direct truncating of page v2
HWPOISON: check and isolate corrupted free pages v2
HWPOISON: Handle hardware poisoned pages in try_to_unmap
HWPOISON: Use bitmask/action code for try_to_unmap behaviour
HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
HWPOISON: Add poison check to page fault handling
HWPOISON: Add basic support for poisoned pages in fault handler v3
HWPOISON: Add new SIGBUS error codes for hardware poison signals
HWPOISON: Add support for poison swap entries v2
HWPOISON: Export some rmap vma locking to outside world
...
Because the binfmt is not different between threads in the same process,
it can be moved from task_struct to mm_struct. And binfmt moudle is
handled per mm_struct instead of task_struct.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
