We can't use LKM_LOCAL for new dentry locks because an unlink and subsequent
re-create of a name/inode pair may result in the lock still being mastered
somewhere in the cluster.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Make use of FS_RENAME_DOES_D_MOVE to avoid a race condition that can occur
during ->rename() if we d_move() outside of the parent directory cluster
locks, and another node discovers the new name (created during the rename)
and unlinks it. d_move() will unconditionally rehash a dentry - which will
leave stale data in the system.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Some file systems want to manually d_move() the dentries involved in a
rename. We can do this by making use of the FS_ODD_RENAME flag if we just
have nfs_rename() unconditionally do the d_move(). While there, we rename
the flag to be more descriptive.
OCFS2 uses this to protect that part of the rename operation with a cluster
lock.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Actually replace the vote calls with the new dentry operations. Make any
necessary adjustments to get the scheme to work.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Replace the dentry vote mechanism with a cluster lock which covers a set
of dentries. This allows us to force d_delete() only on nodes which actually
care about an unlink.
Every node that does a ->lookup() gets a read only lock on the dentry, until
an unlink during which the unlinking node, will request an exclusive lock,
forcing the other nodes who care about that dentry to d_delete() it. The
effect is that we retain a very lightweight ->d_revalidate(), and at the
same time get to make large improvements to the average case performance of
the ocfs2 unlink and rename operations.
This patch adds the higher level API and the dentry manipulation code.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Replace the dentry vote mechanism with a cluster lock which covers a set
of dentries. This allows us to force d_delete() only on nodes which actually
care about an unlink.
Every node that does a ->lookup() gets a read only lock on the dentry, until
an unlink during which the unlinking node, will request an exclusive lock,
forcing the other nodes who care about that dentry to d_delete() it. The
effect is that we retain a very lightweight ->d_revalidate(), and at the
same time get to make large improvements to the average case performance of
the ocfs2 unlink and rename operations.
This patch adds the cluster lock type which OCFS2 can attach to
dentries. A small number of fs/ocfs2/dcache.c functions are stubbed
out so that this change can compile.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
File system lock names are very regular right now, so we really only need to
pass an extra parameter to dlmlock().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We just need to add a namelen field to the user_lock_res structure, and
update a few debug prints. Instead of updating all debug prints, I took the
opportunity to remove a few that are likely unnecessary these days.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
The OCFS2 DLM uses strlen() to determine lock name length, which excludes
the possibility of putting binary values in the name string. Fix this by
requiring that string length be passed in as a parameter.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
An AST can be delivered via the network after a lock has been removed, so no
need to print an error when we see that.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Remove the EXPERIMENTAL flag from the NFS_DIRECTIO option.
Test plan:
Unset the EXPERIMENTAL kernel build option and check to see that the NFS
direct I/O option is still available.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Comments-only change to clarify a detail of the NFS protocol and how it is
implemented in Linux.
Test plan:
None.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
RFC3530 states that the registered port 2049 for the NFS protocol should be
the default configuration in order to allow clients not to use the RPC
binding protocols.
If the mount program sends us a port=0, we therefore substitute port=2049.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Retry a few times before we give up: the error is usually due to ordering
issues with asynchronous RPC calls.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
And slight optimisation of nfs_end_data_update(): directories never have
delegations anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, a read() request will return EIO even if the file has been
deleted on the server, simply because that is what the VM will return
if the call to readpage() fails to update the page.
Ensure that readpage() marks the inode as stale if it receives an ESTALE.
Then return that error to userland.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the open intents tell us that a given lookup is going to result in a,
exclusive create, we currently optimize away the lookup call itself. The
reason is that the lookup would not be atomic with the create RPC call, so
why do it in the first place?
A problem occurs, however, if the VFS aborts the exclusive create operation
after the lookup, but before the call to create the file/directory: in this
case we will end up with a hashed negative dentry in the dcache that has
never been looked up.
Fix this by only actually hashing the dentry once the create operation has
been successfully completed.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix an oops when the referral server is not responding.
Check the error return from nfs4_set_client() in nfs4_create_referral_server.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Teach NFS_ROOT to use the new rpc_create API instead of the old two-call
API for creating an RPC transport.
Test plan:
Compile the kernel with the NFS client build-in, and set CONFIG_NFS_ROOT.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix up warnings from compiling on ppc64.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that we have a copy of the symlink path in the page cache, we can pass
a struct page down to the XDR routines instead of a string buffer.
Test plan:
Connectathon, all NFS versions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently the NFS client does not cache symlinks it creates. They get
cached only when the NFS client reads them back from the server.
Copy the symlink into the page cache before sending it.
Test plan:
Connectathon, all NFS versions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning. But some callers already do a d_drop in the case
of an error return. Make certain we do only one d_drop in all error paths.
This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API. To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.
Test plan:
Connectathon, all versions of NFS.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In the early days of NFS, there was no duplicate reply cache on the server.
Thus retransmitted non-idempotent requests often found that the request had
already completed on the server. To avoid passing an unanticipated return
code to unsuspecting applications, NFS clients would often shunt error
codes that implied the request had been retried but already completed.
Thanks to NFS over TCP, duplicate reply caches on the server, and network
performance and reliability improvements, it is safe to remove such checks.
Test plan:
None.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Replace xprt_create_proto/rpc_create_client call in NFS server callback
functions to use new rpc_create() API.
Test plan:
NFSv4 delegation functionality tests.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Convert NFS client mount logic to use rpc_create() instead of the old
xprt_create_proto/rpc_create_client API.
Test plan:
Mount stress tests.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Replace xprt_create_proto/rpc_create_client with new rpc_create()
interface in the Network Lock Manager.
Note that the semantics of NLM transports is now "hard" instead of "soft"
to provide a better guarantee that lock requests will get to the server.
Test plan:
Repeated runs of Connectathon locking suite. Check network trace to ensure
NLM requests are working correctly.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Remove some unused macros related to accessing an RPC peer address
Test plan:
Compile kernel with CONFIG_NFS option enabled.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
include/linux/sunrpc/clnt.h already includes include/linux/sunrpc/xprt.h.
We can remove xprt.h from source files that already include clnt.h.
Likewise include/linux/sunrpc/timer.h.
Test plan:
Compile kernel with CONFIG_NFS enabled.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Hide the details of how the RPC client stores remote peer addresses from
the Network Lock Manager.
Test plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Invoke security_d_instantiate() on root dentries after allocating them with
dentry_alloc_anon(). Normally dentry_alloc_root() would do that, but we don't
call that as we don't want to assign a name to the root dentry at this point
(we may discover the real name later).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix an error handling problem: nfs_put_client() can be given a NULL pointer if
nfs_free_server() is asked to destroy a partially initialised record.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Make two new proc files available:
/proc/fs/nfsfs/servers
/proc/fs/nfsfs/volumes
The first lists the servers with which we are currently dealing (struct
nfs_client), and the second lists the volumes we have on those servers (struct
nfs_server).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The attached patch makes NFS share superblocks between mounts from the same
server and FSID over the same protocol.
It does this by creating each superblock with a false root and returning the
real root dentry in the vfsmount presented by get_sb(). The root dentry set
starts off as an anonymous dentry if we don't already have the dentry for its
inode, otherwise it simply returns the dentry we already have.
We may thus end up with several trees of dentries in the superblock, and if at
some later point one of anonymous tree roots is discovered by normal filesystem
activity to be located in another tree within the superblock, the anonymous
root is named and materialises attached to the second tree at the appropriate
point.
Why do it this way? Why not pass an extra argument to the mount() syscall to
indicate the subpath and then pathwalk from the server root to the desired
directory? You can't guarantee this will work for two reasons:
(1) The root and intervening nodes may not be accessible to the client.
With NFS2 and NFS3, for instance, mountd is called on the server to get
the filehandle for the tip of a path. mountd won't give us handles for
anything we don't have permission to access, and so we can't set up NFS
inodes for such nodes, and so can't easily set up dentries (we'd have to
have ghost inodes or something).
With this patch we don't actually create dentries until we get handles
from the server that we can use to set up their inodes, and we don't
actually bind them into the tree until we know for sure where they go.
(2) Inaccessible symbolic links.
If we're asked to mount two exports from the server, eg:
mount warthog:/warthog/aaa/xxx /mmm
mount warthog:/warthog/bbb/yyy /nnn
We may not be able to access anything nearer the root than xxx and yyy,
but we may find out later that /mmm/www/yyy, say, is actually the same
directory as the one mounted on /nnn. What we might then find out, for
example, is that /warthog/bbb was actually a symbolic link to
/warthog/aaa/xxx/www, but we can't actually determine that by talking to
the server until /warthog is made available by NFS.
This would lead to having constructed an errneous dentry tree which we
can't easily fix. We can end up with a dentry marked as a directory when
it should actually be a symlink, or we could end up with an apparently
hardlinked directory.
With this patch we need not make assumptions about the type of a dentry
for which we can't retrieve information, nor need we assume we know its
place in the grand scheme of things until we actually see that place.
This patch reduces the possibility of aliasing in the inode and page caches for
inodes that may be accessed by more than one NFS export. It also reduces the
number of superblocks required for NFS where there are many NFS exports being
used from a server (home directory server + autofs for example).
This in turn makes it simpler to do local caching of network filesystems, as it
can then be guaranteed that there won't be links from multiple inodes in
separate superblocks to the same cache file.
Obviously, cache aliasing between different levels of NFS protocol could still
be a problem, but at least that gives us another key to use when indexing the
cache.
This patch makes the following changes:
(1) The server record construction/destruction has been abstracted out into
its own set of functions to make things easier to get right. These have
been moved into fs/nfs/client.c.
All the code in fs/nfs/client.c has to do with the management of
connections to servers, and doesn't touch superblocks in any way; the
remaining code in fs/nfs/super.c has to do with VFS superblock management.
(2) The sequence of events undertaken by NFS mount is now reordered:
(a) A volume representation (struct nfs_server) is allocated.
(b) A server representation (struct nfs_client) is acquired. This may be
allocated or shared, and is keyed on server address, port and NFS
version.
(c) If allocated, the client representation is initialised. The state
member variable of nfs_client is used to prevent a race during
initialisation from two mounts.
(d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
the root filehandle for the mount (fs/nfs/getroot.c). For NFS2/3 we
are given the root FH in advance.
(e) The volume FSID is probed for on the root FH.
(f) The volume representation is initialised from the FSINFO record
retrieved on the root FH.
(g) sget() is called to acquire a superblock. This may be allocated or
shared, keyed on client pointer and FSID.
(h) If allocated, the superblock is initialised.
(i) If the superblock is shared, then the new nfs_server record is
discarded.
(j) The root dentry for this mount is looked up from the root FH.
(k) The root dentry for this mount is assigned to the vfsmount.
(3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
returns; this function now attaches disconnected trees from alternate
roots that happen to be discovered attached to a directory being read (in
the same way nfs_lookup() is made to do for lookup ops).
The new d_materialise_unique() function is now used to do this, thus
permitting the whole thing to be done under one set of locks, and thus
avoiding any race between mount and lookup operations on the same
directory.
(4) The client management code uses a new debug facility: NFSDBG_CLIENT which
is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.
(5) Clone mounts are now called xdev mounts.
(6) Use the dentry passed to the statfs() op as the handle for retrieving fs
statistics rather than the root dentry of the superblock (which is now a
dummy).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Start rpciod in the server common (nfs_client struct) management code rather
than in the superblock management code. This means we only need to "start" it
once per server instead of once per superblock.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Eliminate nfs_server::client_sys in favour of nfs_client::cl_rpcclient as we
only really need one per server that we're talking to since it doesn't have any
security on it.
The retransmission management variables are also moved to the common struct as
they're required to set up the cl_rpcclient connection.
The NFS2/3 client and client_acl connections are thenceforth derived by cloning
the cl_rpcclient connection and post-applying the authorisation flavour.
The code for setting up the initial common connection has been moved to
client.c as nfs_create_rpc_client(). All the NFS program definition tables are
also moved there as that's where they're now required rather than super.c.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the rpc_ops from the nfs_server struct to the nfs_client struct as they're
common to all server records of a particular NFS protocol version.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Make better use of inode* dereferencing macros to hide dereferencing chains
(including NFS_PROTO and NFS_CLIENT).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Maintain a common server record for NFS2/3 as well as for NFS4 so that common
stuff can be moved there from struct nfs_server.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Mark Fasheh