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* NFS: Share NFS superblocks per-protocol per-server per-FSIDDavid Howells2006-09-221-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* NFS: Generalise the nfs_client structureDavid Howells2006-09-221-122/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* NFS: Rename nfs_server::nfs4_stateDavid Howells2006-09-221-5/+5
| | | | | | | | 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>
* NFS: Rename struct nfs4_client to struct nfs_clientDavid Howells2006-09-221-25/+25
| | | | | | | | 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>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-301-1/+0
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* NFSv4: SETCLIENTID_CONFIRM should handle NFS4ERR_DELAY/NFS4ERR_RESOURCETrond Myklebust2006-03-201-0/+1
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Remove requirement for machine creds for the "setclientid" operationTrond Myklebust2006-01-061-26/+45
| | | | | | Use a cred from the nfs4_client->cl_state_owners list. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Remove requirement for machine creds for the "renew" operationTrond Myklebust2006-01-061-1/+15
| | | | | | | | | | | | | | | | | In RFC3530, the RENEW operation is allowed to use either the same principal, RPC security flavour and (if RPCSEC_GSS), the same mechanism and service that was used for SETCLIENTID_CONFIRM OR Any principal, RPC security flavour and service combination that currently has an OPEN file on the server. Choose the latter since that doesn't require us to keep credentials for the same principal for the entire duration of the mount. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Convert instances of kernel_thread() to kthread()Trond Myklebust2006-01-061-30/+16
| | | | | | | Convert private implementations in NFSv4 state recovery and delegation code to use kthreads. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: State recovery cleanupTrond Myklebust2006-01-061-10/+13
| | | | | | Use wait_on_bit() when waiting for state recovery to complete. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Make nfs4_state track O_RDWR, O_RDONLY and O_WRONLY separatelyTrond Myklebust2006-01-061-14/+17
| | | | | | | | | | | | | A closer reading of RFC3530 reveals that OPEN_DOWNGRADE must always specify a access modes that have been the argument of a previous OPEN operation. IOW: doing OPEN(O_RDWR) and then OPEN_DOWNGRADE(O_WRONLY) is forbidden unless the user called OPEN(O_WRONLY) In order to fix that, we really need to track the three possible open states separately. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix buggy nfs_wait_on_sequence()Trond Myklebust2005-11-251-10/+10
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] kfree cleanup: fsJesper Juhl2005-11-071-6/+3
| | | | | | | | | | This is the fs/ part of the big kfree cleanup patch. Remove pointless checks for NULL prior to calling kfree() in fs/. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* NFSv4: Fix recovery of flock() locks.Trond Myklebust2005-11-041-2/+2
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix problem with OPEN_DOWNGRADETrond Myklebust2005-11-041-33/+0
| | | | | | | | | | | | | | | | | RFC 3530 states that for OPEN_DOWNGRADE "The share_access and share_deny bits specified must be exactly equal to the union of the share_access and share_deny bits specified for some subset of the OPENs in effect for current openowner on the current file. Setattr is currently violating the NFSv4 rules for OPEN_DOWNGRADE in that it may cause a downgrade from OPEN4_SHARE_ACCESS_BOTH to OPEN4_SHARE_ACCESS_WRITE despite the fact that there exists no open file with O_WRONLY access mode. Fix the problem by replacing nfs4_find_state() with a modified version of nfs_find_open_context(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix a race between open() and close()Trond Myklebust2005-11-041-28/+30
| | | | | | | We must not remove the nfs4_state structure from the inode open lists before we are in sequence lock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix up locking for nfs4_state_ownerTrond Myklebust2005-10-201-5/+15
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Final tweak to sequence idTrond Myklebust2005-10-201-10/+13
| | | | | | Sacrifice queueing fairness for performance. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix an oopsable condition in nfs_free_seqidTrond Myklebust2005-10-181-8/+1
| | | | | | | Storing a pointer to the struct rpc_task in the nfs_seqid is broken since the nfs_seqid may be freed well after the task has been destroyed. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Make NFS clean up byte range locks asynchronouslyTrond Myklebust2005-10-181-1/+1
| | | | | | Currently we fail to do so if the process was signalled. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Remove nfs4_client->cl_sem from close() pathTrond Myklebust2005-10-181-8/+1
| | | | | | | | | | We no longer need to worry about collisions between close() and the state recovery code, since the new close will automatically recheck the file state once it is done waiting on its sequence slot. Ditto for the nfs4_proc_locku() procedure. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Remove obsolete state_owner and lock_owner semaphoresTrond Myklebust2005-10-181-11/+4
| | | | | | | OPEN, CLOSE, etc no longer need these semaphores to ensure ordering of requests. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix a potential CLOSE raceTrond Myklebust2005-10-181-1/+5
| | | | | | | | | | Once the state_owner and lock_owner semaphores get removed, it will be possible for other OPEN requests to reopen the same file if they have lower sequence ids than our CLOSE call. This patch ensures that we recheck the file state once nfs_wait_on_sequence() has completed waiting. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Add functions to order RPC callsTrond Myklebust2005-10-181-26/+119
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | NFSv4 file state-changing functions such as OPEN, CLOSE, LOCK,... are all labelled with "sequence identifiers" in order to prevent the server from reordering RPC requests, as this could cause its file state to become out of sync with the client. Currently the NFS client code enforces this ordering locally using semaphores to restrict access to structures until the RPC call is done. This, of course, only works with synchronous RPC calls, since the user process must first grab the semaphore. By dropping semaphores, and instead teaching the RPC engine to hold the RPC calls until they are ready to be sent, we can extend this process to work nicely with asynchronous RPC calls too. This patch adds a new list called "rpc_sequence" that defines the order of the RPC calls to be sent. We add one such list for each state_owner. When an RPC call is ready to be sent, it checks if it is top of the rpc_sequence list. If so, it proceeds. If not, it goes back to sleep, and loops until it hits top of the list. Once the RPC call has completed, it can then bump the sequence id counter, and remove itself from the rpc_sequence list, and then wake up the next sleeper. Note that the state_owner sequence ids and lock_owner sequence ids are all indexed to the same rpc_sequence list, so OPEN, LOCK,... requests are all ordered w.r.t. each other. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] NFSv4: Clean up nfs4 lock state accountingTrond Myklebust2005-06-221-99/+79
| | | | | | Ensure that lock owner structures are not released prematurely. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] RPC: [PATCH] improve rpcauthauth_create error returnsJ. Bruce Fields2005-06-221-1/+2
| | | | | | | | | | | | Currently we return -ENOMEM for every single failure to create a new auth. This is actually accurate for auth_null and auth_unix, but for auth_gss it's a bit confusing. Allow rpcauth_create (and the ->create methods) to return errors. With this patch, the user may sometimes see an EINVAL instead. Whee. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] NFS: Header file cleanup...Trond Myklebust2005-06-221-9/+3
| | | | | | | - Move NFSv4 state definitions into a private header file. - Clean up gunk in nfs_fs.h Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* Linux-2.6.12-rc2Linus Torvalds2005-04-161-0/+932
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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