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path: root/fs/nfs/internal.h
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2006-09-22NFS: Add server and volume lists to /procDavid Howells
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>
2006-09-22NFS: Share NFS superblocks per-protocol per-server per-FSIDDavid Howells
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>
2006-09-22NFS: Eliminate client_sys in favour of cl_rpcclientDavid Howells
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>
2006-09-22NFS: Generalise the nfs_client structureDavid Howells
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>
2006-09-22NFS: Fix up split of fs/nfs/inode.cDavid Howells
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>
2006-09-22NFS: Add an ACCESS cache memory shrinkerTrond Myklebust
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>
2006-07-02[PATCH] nfs: non-procfs build fixDominik Hackl
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>
2006-06-27[PATCH] fix static linking of NFSDavid Brownell
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>
2006-06-25git-nfs-build-fixesAndrew Morton
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>
2006-06-09NFS: Split fs/nfs/inode.cDavid Howells
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>