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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>
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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>
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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>
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Generalise the nfs_client structure by:
(1) Moving nfs_client to a more general place (nfs_fs_sb.h).
(2) Renaming its maintenance routines to be non-NFS4 specific.
(3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
and move the declarations to internal.h.
(4) Make nfs_find/get_client() take a full sockaddr_in to include the port
number (will be required for NFS2/3).
(5) Make nfs_find/get_client() take the NFS protocol version (again will be
required to differentiate NFS2, 3 & 4 client records).
Also:
(6) Make nfs_client construction proceed akin to inodes, marking them as under
construction and providing a function to indicate completion.
(7) Make nfs_get_client() wait interruptibly if it finds a client that it can
share, but that client is currently being constructed.
(8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Fix ups for the splitting of the superblock stuff out of fs/nfs/inode.c,
including:
(*) Move the callback tcpport module param into callback.c.
(*) Move the idmap cache timeout module param into idmap.c.
(*) Changes to internal.h:
(*) namespace-nfs4.c was renamed to nfs4namespace.c.
(*) nfs_stat_to_errno() is in nfs2xdr.c, not nfs4xdr.c.
(*) nfs4xdr.c is contingent on CONFIG_NFS_V4.
(*) nfs4_path() is only uses if CONFIG_NFS_V4 is set.
Plus also:
(*) The sec_flavours[] table should really be const.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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A pinned inode may in theory end up filling memory with cached ACCESS
calls. This patch ensures that the VM may shrink away the cache in these
particular cases.
The shrinker works by iterating through the list of inodes on the global
nfs_access_lru_list, and removing the least recently used access
cache entry until it is done (or until the entire cache is empty).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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This fixes a bug in fs/nfs which makes it impossible to build nfs
without having procfs enabled.
Signed-off-by: Dominik Hackl <dominik@hackl.dhs.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Builds on ARM report link problems with common configurations like
statically linked NFS (for nfsroot). The symptom is that __init
section code references __exit section code; that won't work since
the exit sections are discarded (since they can never be called).
The best fix for these particular cases would be an "__init_or_exit"
section annotation.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Fix various problems with nfs4 disabled. And various other things.
In file included from fs/nfs/inode.c:50:
fs/nfs/internal.h:24: error: static declaration of 'nfs_do_refmount' follows non-static declaration
include/linux/nfs_fs.h:320: error: previous declaration of 'nfs_do_refmount' was here
fs/nfs/internal.h:65: warning: 'struct nfs4_fs_locations' declared inside parameter list
fs/nfs/internal.h:65: warning: its scope is only this definition or declaration, which is probably not what you want
fs/nfs/internal.h: In function 'nfs4_path':
fs/nfs/internal.h:97: error: 'struct nfs_server' has no member named 'mnt_path'
fs/nfs/inode.c: In function 'init_once':
fs/nfs/inode.c:1116: error: 'struct nfs_inode' has no member named 'open_states'
fs/nfs/inode.c:1116: error: 'struct nfs_inode' has no member named 'delegation'
fs/nfs/inode.c:1116: error: 'struct nfs_inode' has no member named 'delegation_state'
fs/nfs/inode.c:1116: error: 'struct nfs_inode' has no member named 'rwsem'
distcc[26452] ERROR: compile fs/nfs/inode.c on g5/64 failed
make[1]: *** [fs/nfs/inode.o] Error 1
make: *** [fs/nfs/inode.o] Error 2
make: *** Waiting for unfinished jobs....
In file included from fs/nfs/nfs3xdr.c:26:
fs/nfs/internal.h:24: error: static declaration of 'nfs_do_refmount' follows non-static declaration
include/linux/nfs_fs.h:320: error: previous declaration of 'nfs_do_refmount' was here
fs/nfs/internal.h:65: warning: 'struct nfs4_fs_locations' declared inside parameter list
fs/nfs/internal.h:65: warning: its scope is only this definition or declaration, which is probably not what you want
fs/nfs/internal.h: In function 'nfs4_path':
fs/nfs/internal.h:97: error: 'struct nfs_server' has no member named 'mnt_path'
distcc[26486] ERROR: compile fs/nfs/nfs3xdr.c on g5/64 failed
make[1]: *** [fs/nfs/nfs3xdr.o] Error 1
make: *** [fs/nfs/nfs3xdr.o] Error 2
In file included from fs/nfs/nfs3proc.c:24:
fs/nfs/internal.h:24: error: static declaration of 'nfs_do_refmount' follows non-static declaration
include/linux/nfs_fs.h:320: error: previous declaration of 'nfs_do_refmount' was here
fs/nfs/internal.h:65: warning: 'struct nfs4_fs_locations' declared inside parameter list
fs/nfs/internal.h:65: warning: its scope is only this definition or declaration, which is probably not what you want
fs/nfs/internal.h: In function 'nfs4_path':
fs/nfs/internal.h:97: error: 'struct nfs_server' has no member named 'mnt_path'
distcc[26469] ERROR: compile fs/nfs/nfs3proc.c on bix/32 failed
make[1]: *** [fs/nfs/nfs3proc.o] Error 1
make: *** [fs/nfs/nfs3proc.o] Error 2
**FAILED**
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Cc: Andy Adamson <andros@citi.umich.edu>
Cc: Chuck Lever <cel@netapp.com>
Cc: David Howells <dhowells@redhat.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Manoj Naik <manoj@almaden.ibm.com>
Cc: Marc Eshel <eshel@almaden.ibm.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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As fs/nfs/inode.c is rather large, heterogenous and unwieldy, the attached
patch splits it up into a number of files:
(*) fs/nfs/inode.c
Strictly inode specific functions.
(*) fs/nfs/super.c
Superblock management functions for NFS and NFS4, normal access, clones
and referrals. The NFS4 superblock functions _could_ move out into a
separate conditionally compiled file, but it's probably not worth it as
there're so many common bits.
(*) fs/nfs/namespace.c
Some namespace-specific functions have been moved here.
(*) fs/nfs/nfs4namespace.c
NFS4-specific namespace functions (this could be merged into the previous
file). This file is conditionally compiled.
(*) fs/nfs/internal.h
Inter-file declarations, plus a few simple utility functions moved from
fs/nfs/inode.c.
Additionally, all the in-.c-file externs have been moved here, and those
files they were moved from now includes this file.
For the most part, the functions have not been changed, only some multiplexor
functions have changed significantly.
I've also:
(*) Added some extra banner comments above some functions.
(*) Rearranged the function order within the files to be more logical and
better grouped (IMO), though someone may prefer a different order.
(*) Reduced the number of #ifdefs in .c files.
(*) Added missing __init and __exit directives.
Signed-Off-By: David Howells <dhowells@redhat.com>
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