The following set of patches fix known issues with the 2.6.18-rc4 NFS client code, and significantly enhance the support for NFSv4.
From: Nikita Danilov <nikita@clusterfs.com>
NFS: Fix a potential deadlock in nfs_release_page
nfs_wb_page() waits on request completion and, as a result, is not safe to be called from nfs_release_page() invoked by VM scanner as part of GFP_NOFS allocation. Fix possible deadlock by analyzing gfp mask and refusing to release page if __GFP_FS is not set.
Signed-off-by: Nikita Danilov <danilov@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: ASANO Masahiro <masano@tnes.nec.co.jp>
VFS: add lookup hint for network file systems
I'm trying to speeding up mkdir(2) for network file systems. A typical mkdir(2) calls two inode_operations: lookup and mkdir. The lookup operation would fail with ENOENT in common case. I think it is unnecessary because the subsequent mkdir operation can check it. In case of creat(2), lookup operation is called with the LOOKUP_CREATE flag, so individual filesystem can omit real lookup. e.g. nfs_lookup().
Here is a sample patch which uses LOOKUP_CREATE and O_EXCL on mkdir, symlink and mknod. This uses the gadget for creat(2).
And here is the result of a benchmark on NFSv3. mkdir(2) 10,000 times: original 50.5 sec patched 29.0 sec
Signed-off-by: ASANO Masahiro <masano@tnes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
VFS: Fix access("file", X_OK) in the presence of ACLs
Currently, the access() call will return incorrect information on NFS if there exists an ACL that grants execute access to the user on a regular file. The reason the information is incorrect is that the VFS overrides this execute access in open_exec() by checking (inode->i_mode & 0111).
This patch propagates the VFS execute bit check back into the generic permission() call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
VFS: Remove redundant open-coded mode bit check in prepare_binfmt().
The check in prepare_binfmt() for inode->i_mode & 0111 is redundant, since open_exec() will already have done that.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
VFS: Remove redundant open-coded mode bit checks in open_exec().
The check in open_exec() for inode->i_mode & 0111 has been made redundant by the fix to permission().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
SUNRPC: make rpc_unlink() take a dentry argument instead of a path
Signe-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: clean up rpc_rmdir
Make it take a dentry argument instead of a path
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
SUNRPC: rpc_unlink() must check for unhashed dentries
A prior call to rpc_depopulate() by rpc_rmdir() on the parent directory may have already called simple_unlink() on this entry. Add the same check to rpc_rmdir(). Also remove a redundant call to rpc_close_pipes() in rpc_rmdir.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
SUNRPC: Fix dentry refcounting issues with users of rpc_pipefs
rpc_unlink() and rpc_rmdir() will dput the dentry reference for you.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
fs/locks.c: Fix fcntl(F_SETSIG) on leases
fcntl(F_SETSIG) no longer works on leases because lease_release_private_callback() gets called as the lease is copied in order to initialise it. The problem is that lease_alloc() performs an unnecessary initialisation, which sets the lease_manager_ops. Avoid the problem by allocating the target lease structure using locks_alloc_lock().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
LOCKD: Fix a deadlock in nlm_traverse_files()
nlm_traverse_files() is not allowed to hold the nlm_file_mutex while calling nlm_inspect file, since it may end up calling nlm_release_file() when releaseing the blocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Add a new ACCESS rpc call cache to the linux nfs client
The current access cache only allows one entry at a time to be cached for each inode. Add a per-inode red-black tree in order to allow more than one to be cached at a time.
Should significantly cut down the time spent in path traversal for shared directories such as ${PATH}, /usr/share, etc.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Add a global LRU list for the ACCESS cache
...in order to allow the addition of a memory shrinker.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Add an ACCESS cache memory shrinker
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>
From: David Howells <dhowells@redhat.com>
NFS: Add dentry materialisation op
The attached patch adds a new directory cache management function that prepares a disconnected anonymous function to be connected into the dentry tree. The anonymous dentry is transferred the name and parentage from another dentry.
The following changes were made in [try #2]:
(*) d_materialise_dentry() now switches the parentage of the two nodes around correctly when one or other of them is self-referential.
The following changes were made in [try #7]:
(*) d_instantiate_unique() has had the interior part split out as function __d_instantiate_unique(). Callers of this latter function must be holding the appropriate locks.
(*) _d_rehash() has been added as a wrapper around __d_rehash() to call it with the most obvious hash list (the one from the name). d_rehash() now calls _d_rehash().
(*) d_materialise_dentry() is now __d_materialise_dentry() and is static.
(*) d_materialise_unique() added to perform the combination of d_find_alias(), d_materialise_dentry() and d_add_unique() that the NFS client was doing twice, all within a single dcache_lock critical section. This reduces the number of times two different spinlocks were being accessed.
The following further changes were made:
(*) Add the dentries onto their parents d_subdirs lists.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Fix up split of fs/nfs/inode.c
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>
From: David Howells <dhowells@redhat.com>
NFS: Disambiguate nfs_stat_to_errno()
Rename the NFS4 version of nfs_stat_to_errno() so that it doesn't conflict with the common one used by NFS2 and NFS3.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Fix NFS4 callback up/down prototypes
Make the nfs_callback_up()/down() prototypes just do nothing if NFS4 is not enabled. Also make the down function void type since we can't really do anything if it fails.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Rename struct nfs4_client to struct nfs_client
Rename struct nfs4_client to struct nfs_client so that it can become the basis for a general client record for NFS2 and NFS3 in addition to NFS4.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Rename nfs_server::nfs4_state
Rename nfs_server::nfs4_state to nfs_client as it will be used to represent the client state for NFS2 and NFS3 also.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Return an error when starting the idmapping pipe
Return an error when starting the idmapping pipe so that we can detect it failing.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Add a lookupfh NFS RPC op
Add a lookup filehandle NFS RPC op so that a file handle can be looked up without requiring dentries and inodes and other VFS stuff when doing an NFS4 pathwalk during mounting.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Add a server capabilities NFS RPC op
Add a set_capabilities NFS RPC op so that the server capabilities can be set.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Generalise the nfs_client structure
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>
From: David Howells <dhowells@redhat.com>
NFS: Use the dentry superblock directly in nfs_statfs()
Use the nominated dentry's superblock directly in the NFS statfs() op to get a file handle, rather than using s_root (which will become a dummy dentry in a future patch).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Add extra const qualifiers
Add some extra const qualifiers into NFS.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: David Howells <dhowells@redhat.com>
NFS: Maintain a common server record for NFS2/3 as well as for NFS4
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>
From: David Howells <dhowells@redhat.com>
NFS: Make better use of inode* dereferencing macros
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>
From: David Howells <dhowells@redhat.com>
NFS: Move rpc_ops from nfs_server to nfs_client
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>
From: David Howells <dhowells@redhat.com>
NFS: Eliminate client_sys in favour of cl_rpcclient
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>
From: David Howells <dhowells@redhat.com>
NFS: Start rpciod in server common management
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>
From: David Howells <dhowells@redhat.com>
NFS: Share NFS superblocks per-protocol per-server per-FSID
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>
From: David Howells <dhowells@redhat.com>
NFS: Add server and volume lists to /proc
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>
From: David Howells <dhowells@redhat.com>
NFS: Fix error handling
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>
From: David Howells <dhowells@redhat.com>
NFS: Secure the roots of the NFS subtrees in a shared superblock
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>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Ensure NFSv2/v3 mounts respect the NFS_MOUNT_SECFLAVOUR flag
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
From: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Fix nfs_alloc_client()
The scheme to indicate which services have been started up appears to be seriously broken.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
All of the above
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