summaryrefslogtreecommitdiffstats
path: root/fs/nfs/idmap.c
Commit message (Collapse)AuthorAgeFilesLines
* NFS: Force the legacy idmapper to be single threadedBryan Schumaker2012-06-201-5/+8
| | | | | | | | | It was initially coded under the assumption that there would only be one request at a time, so use a lock to enforce this requirement.. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> CC: stable@vger.kernel.org [3.4+] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Add memory barriers to the nfs_client->cl_cons_state initialisationTrond Myklebust2012-05-231-0/+1
| | | | | | | | Ensure that a process that uses the nfs_client->cl_cons_state test for whether the initialisation process is finished does not read stale data. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Fix a race in the net namespace mount notificationTrond Myklebust2012-05-231-0/+15
| | | | | | | | | | | | | | Since the struct nfs_client gets added to the global nfs_client_list before it is initialised, it is possible that rpc_pipefs_event can end up trying to create idmapper entries on such a thing. The solution is to have the mount notification wait for the initialisation of each nfs_client to complete, and then to skip any entries for which the it failed. Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
* NFS: Use proper naming conventions for the nfs_client.net fieldChuck Lever2012-05-221-2/+2
| | | | | | | | | | | Clean up: When naming fields and data types, follow established conventions to facilitate accurate grep/cscope searches. Introduced by commit e50a7a1a "NFS: make NFS client allocated per network namespace context," Tue Jan 10, 2012. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: kmalloc() doesn't return an ERR_PTR()Dan Carpenter2012-05-141-7/+3
| | | | | | | | Obviously we should check for NULL here instead of IS_ERR(). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@vger.kernel.org [3.4] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: get module in idmap PipeFS notifier callbackStanislav Kinsbursky2012-04-281-0/+4
| | | | | | | | | This is bug fix. Notifier callback is called from SUNRPC module. So before dereferencing NFS module we have to make sure, that it's alive. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* Merge tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds2012-03-231-389/+344
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NFS client updates for Linux 3.4 from Trond Myklebust: "New features include: - Add NFS client support for containers. This should enable most of the necessary functionality, including lockd support, and support for rpc.statd, NFSv4 idmapper and RPCSEC_GSS upcalls into the correct network namespace from which the mount system call was issued. - NFSv4 idmapper scalability improvements Base the idmapper cache on the keyring interface to allow concurrent access to idmapper entries. Start the process of migrating users from the single-threaded daemon-based approach to the multi-threaded request-key based approach. - NFSv4.1 implementation id. Allows the NFSv4.1 client and server to mutually identify each other for logging and debugging purposes. - Support the 'vers=4.1' mount option for mounting NFSv4.1 instead of having to use the more counterintuitive 'vers=4,minorversion=1'. - SUNRPC tracepoints. Start the process of adding tracepoints in order to improve debugging of the RPC layer. - pNFS object layout support for autologin. Important bugfixes include: - Fix a bug in rpc_wake_up/rpc_wake_up_status that caused them to fail to wake up all tasks when applied to priority waitqueues. - Ensure that we handle read delegations correctly, when we try to truncate a file. - A number of fixes for NFSv4 state manager loops (mostly to do with delegation recovery)." * tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (224 commits) NFS: fix sb->s_id in nfs debug prints xprtrdma: Remove assumption that each segment is <= PAGE_SIZE xprtrdma: The transport should not bug-check when a dup reply is received pnfs-obj: autologin: Add support for protocol autologin NFS: Remove nfs4_setup_sequence from generic rename code NFS: Remove nfs4_setup_sequence from generic unlink code NFS: Remove nfs4_setup_sequence from generic read code NFS: Remove nfs4_setup_sequence from generic write code NFS: Fix more NFS debug related build warnings SUNRPC/LOCKD: Fix build warnings when CONFIG_SUNRPC_DEBUG is undefined nfs: non void functions must return a value SUNRPC: Kill compiler warning when RPC_DEBUG is unset SUNRPC/NFS: Add Kbuild dependencies for NFS_DEBUG/RPC_DEBUG NFS: Use cond_resched_lock() to reduce latencies in the commit scans NFSv4: It is not safe to dereference lsp->ls_state in release_lockowner NFS: ncommit count is being double decremented SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up() Try using machine credentials for RENEW calls NFSv4.1: Fix a few issues in filelayout_commit_pagelist NFSv4.1: Clean ups and bugfixes for the pNFS read/writeback/commit code ...
| * NFS: Check return value from rpc_queue_upcall()Bryan Schumaker2012-03-121-2/+7
| | | | | | | | | | | | | | | | | | This function could fail to queue the upcall if rpc.idmapd is not running, causing a warning message to be printed. Instead, I want to check the return value and revoke the key if the upcall can't be run. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: Fix a number of sparse warningsTrond Myklebust2012-03-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix a number of "warning: symbol 'foo' was not declared. Should it be static?" conditions. Fix 2 cases of "warning: Using plain integer as NULL pointer" fs/nfs/delegation.c:263:31: warning: restricted fmode_t degrades to integer - We want to allow upgrades to a WRITE delegation, but should otherwise consider servers that hand out duplicate delegations to be borken. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: Store the legacy idmapper result in the keyringBryan Schumaker2012-03-011-388/+166
| | | | | | | | | | | | | | | | | | | | This patch removes the old hashmap-based caching and instead uses a "request key actor" to place an upcall to the legacy idmapper rather than going through /sbin/request-key. This will only be used as a fallback if /etc/request-key.conf isn't configured to use nfsidmap. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: release per-net clients lock before calling PipeFS dentries creationStanislav Kinsbursky2012-02-271-6/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | v3: 1) Lookup for client is performed from the beginning of the list on each PipeFS event handling operation. Lockdep is sad otherwise, because inode mutex is taken on PipeFS dentry creation, which can be called on mount notification, where this per-net client lock is taken on clients list walk. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFSv4: Further reduce the footprint of the idmapperTrond Myklebust2012-02-151-6/+36
| | | | | | | | | | | | | | | | Don't allocate the legacy idmapper tables until we actually need them. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Reviewed-by: Jeff Layton <jlayton@redhat.com>
| * NFSv4: Reduce the footprint of the idmapperTrond Myklebust2012-02-151-3/+13
| | | | | | | | | | | | | | | | | | Instead of pre-allocating the storage for all the strings, we can significantly reduce the size of that table by doing the allocation when we do the downcall. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Reviewed-by: Jeff Layton <jlayton@redhat.com>
| * NFS: build fixed in case of NFS_USE_NEW_IDMAPPER is undefinedStanislav Kinsbursky2012-02-061-0/+1
| | | | | | | | | | Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: make nfs_client_lock per net nsStanislav Kinsbursky2012-02-061-2/+2
| | | | | | | | | | | | | | | | This patch makes nfs_clients_lock allocated per network namespace. All items it protects are already network namespace aware. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: make nfs_client_list per net nsStanislav Kinsbursky2012-02-061-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch splits global list of NFS clients into per-net-ns array of lists. This looks more strict and clearer. BTW, this patch also makes "/proc/fs/nfsfs/servers" entry content depends on /proc mount owner pid namespace. See below for details. NOTE: few words about how was /proc/fs/nfsfs/ entries content show per network namespace done. This is a little bit tricky and not the best is could be. But it's cheap (proper fix for /proc conteinerization is a hard nut to crack). The idea is simple: take proper network namespace from pid namespace child reaper nsproxy of /proc/ mount creator. This actually means, that if there are 2 containers with different net namespace sharing pid namespace, then read of /proc/fs/nfsfs/ entries will always return content, taken from net namespace of pid namespace creator task (and thus second namespace set wil be unvisible). Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: Keep idmapper include files in one placeBryan Schumaker2012-02-061-35/+31
| | | | | | | | | | Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: Fall back on old idmapper if request_key() failsBryan Schumaker2012-02-061-54/+37
| | | | | | | | | | | | | | | | | | | | | | | | This patch removes the CONFIG_NFS_USE_NEW_IDMAPPER compile option. First, the idmapper will attempt to map the id using /sbin/request-key and nfsidmap. If this fails (if /etc/request-key.conf is not configured properly) then the idmapper will call the legacy code to perform the mapping. I left a comment stating where the legacy code begins to make it easier for somebody to remove in the future. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: start printks w/ NFS: even if __func__ shownWeston Andros Adamson2012-02-061-2/+4
| | | | | | | | | | | | | | | | This patch addresses printks that have some context to show that they are from fs/nfs/, but for the sake of consistency now start with NFS: Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: printks in fs/nfs/ should start with NFS:Weston Andros Adamson2012-02-061-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Messages like "Got error -10052 from the server on DESTROY_SESSION. Session has been destroyed regardless" can be confusing to users who aren't very familiar with NFS. NOTE: This patch ignores any printks() that start by printing __func__ - that will be in a separate patch. Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: idmap PipeFS notifier introducedStanislav Kinsbursky2012-01-311-0/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | v2: 1) Added "nfs_idmap_init" and "nfs_idmap_quit" definitions for kernels built without CONFIG_NFS_V4 option set. This patch subscribes NFS clients to RPC pipefs notifications. Idmap notifier is registering on NFS module load. This notifier callback is responsible for creation/destruction of PipeFS idmap pipe dentry for NFS4 clients. Since ipdmap pipe is created in rpc client pipefs directory, we have make sure, that this directory has been created already. IOW RPC client notifier callback has been called already. To achive this, PipeFS notifier priorities has been introduced (RPC clients notifier priority is greater than NFS idmap one). But this approach gives another problem: unlink for RPC client directory will be called before NFS idmap pipe unlink on UMOUNT event and will fail, because directory is not empty. The solution, introduced in this patch, is to try to remove client directory once again after idmap pipe was unlinked. This looks like ugly hack, so probably it should be replaced in some more elegant way. Note that no locking required in notifier callback because PipeFS superblock pointer is passed as an argument from it's creation or destruction routine and thus we can be sure about it's validity. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * NFS: handle NFS idmap pipe PipeFS dentries by network namespace aware routinesStanislav Kinsbursky2012-01-311-8/+53
| | | | | | | | | | | | | | | | | | This patch makes NFS idmap pipes dentries allocated and destroyed in network namespace context by PipeFS network namespace aware routines. Network namespace context is obtained from nfs_client structure. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * SUNRPC: remove RPC PipeFS mount point reference from RPC clientStanislav Kinsbursky2012-01-311-2/+2
| | | | | | | | | | | | | | This is a cleanup patch. We don't need this reference anymore. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * SUNRPC: split SUNPRC PipeFS dentry and private pipe data creationStanislav Kinsbursky2012-01-311-8/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a final step towards to removing PipeFS inode references from kernel code other than PipeFS itself. It makes all kernel SUNRPC PipeFS users depends on pipe private data, which state depend on their specific operations, etc. This patch completes SUNRPC PipeFS preparations and allows to create pipe private data and PipeFS dentries independently. Next step will be making SUNPRC PipeFS dentries allocated by SUNRPC PipeFS network namespace aware routines. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
| * SUNPRC: cleanup RPC PipeFS pipes upcall interfaceStanislav Kinsbursky2012-01-311-2/+2
| | | | | | | | | | | | | | | | RPC pipe upcall doesn't requires only private pipe data. Thus RPC inode references in this code can be removed. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* | KEYS: Allow special keyrings to be clearedDavid Howells2012-01-191-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | The kernel contains some special internal keyrings, for instance the DNS resolver keyring : 2a93faf1 I----- 1 perm 1f030000 0 0 keyring .dns_resolver: empty It would occasionally be useful to allow the contents of such keyrings to be flushed by root (cache invalidation). Allow a flag to be set on a keyring to mark that someone possessing the sysadmin capability can clear the keyring, even without normal write access to the keyring. Set this flag on the special keyrings created by the DNS resolver, the NFS identity mapper and the CIFS identity mapper. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* NFSv4: Save the owner/group name string when doing openTrond Myklebust2012-01-071-0/+83
| | | | | | | | | | | | | | | ...so that we can do the uid/gid mapping outside the asynchronous RPC context. This fixes a bug in the current NFSv4 atomic open code where the client isn't able to determine what the true uid/gid fields of the file are, (because the asynchronous nature of the OPEN call denies it the ability to do an upcall) and so fills them with default values, marking the inode as needing revalidation. Unfortunately, in some cases, the VFS will do some additional sanity checks on the file, and may override the server's decision to allow the open because it sees the wrong owner/group fields. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* SUNRPC/NFS: make rpc pipe upcall genericPeng Tao2011-10-181-24/+1
| | | | | | | | | | The same function is used by idmap, gss and blocklayout code. Make it generic. Signed-off-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Jim Rees <rees@umich.edu> Cc: stable@kernel.org [3.0] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* treewide: remove duplicate includesVitaliy Ivanov2011-06-201-5/+2
| | | | | | | | Many stupid corrections of duplicated includes based on the output of scripts/checkincludes.pl. Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* NFSv4: Send unmapped uid/gids to the server when using auth_sysTrond Myklebust2011-03-111-8/+16
| | | | | | | | | | The new behaviour is enabled using the new module parameter 'nfs4_disable_idmapping'. Note that if the server rejects an unmapped uid or gid, then the client will automatically switch back to using the idmapper. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: cleanup idmapper functions to take an nfs_server argumentTrond Myklebust2011-03-111-12/+12
| | | | | | ...instead of the nfs_client. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: Send unmapped uid/gids to the server if the idmapper failsTrond Myklebust2011-03-111-4/+26
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFSv4: If the server sends us a numeric uid/gid then accept itTrond Myklebust2011-03-111-2/+26
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* nfs: fix mispelling of idmap CONFIG symbolJ. Bruce Fields2011-01-041-1/+1
| | | | | | | | Trivial, but confusing when you're trying to grep through this code.... Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* nfs: testing the wrong variableDan Carpenter2010-10-281-1/+1
| | | | | | | | The intent was to test "*desc" for allocation failures, but it tests "desc" which is always a valid pointer here. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: new idmapperBryan Schumaker2010-10-071-2/+209
| | | | | | | | | | | | | | | This patch creates a new idmapper system that uses the request-key function to place a call into userspace to map user and group ids to names. The old idmapper was single threaded, which prevented more than one request from running at a single time. This means that a user would have to wait for an upcall to finish before accessing a cached result. The upcall result is stored on a keyring of type id_resolver. See the file Documentation/filesystems/nfs/idmapper.txt for instructions. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> [Trond: fix up the return value of nfs_idmap_lookup_name and clean up code] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* SUNRPC: Replace rpc_client->cl_dentry and cl_mnt, with a cl_pathTrond Myklebust2009-08-091-2/+2
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* SUNRPC: Constify rpc_pipe_ops...Trond Myklebust2009-08-091-1/+1
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* nfs: fix sparse warningsHarvey Harrison2008-02-201-1/+1
| | | | | | | | | | | | fs/nfs/nfs4state.c:788:34: warning: Using plain integer as NULL pointer fs/nfs/delegation.c:52:34: warning: Using plain integer as NULL pointer fs/nfs/idmap.c:312:12: warning: Using plain integer as NULL pointer fs/nfs/callback_xdr.c:257:6: warning: Using plain integer as NULL pointer fs/nfs/callback_xdr.c:270:6: warning: Using plain integer as NULL pointer fs/nfs/callback_xdr.c:281:6: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Use size_t for storing name lengthsChuck Lever2008-01-301-3/+3
| | | | | | | | Clean up: always use the same type when handling buffer lengths. As a bonus, this prevents a mixed sign comparison in idmap_lookup_name. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Fix use of copy_to_user() in idmap_pipe_upcallChuck Lever2008-01-301-8/+6
| | | | | | | | | The idmap_pipe_upcall() function expects the copy_to_user() function to return a negative error value if the call fails, but copy_to_user() returns an unsigned long number of bytes that couldn't be copied. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Clean up fs/nfs/idmap.cChuck Lever2008-01-301-43/+44
| | | | | | | | Clean up white space damage and use standard kernel coding conventions for return statements. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: use __set_current_state()Milind Arun Choudhary2007-05-091-2/+2
| | | | | | | | | | use __set_current_state(TASK_*) instead of current->state = TASK_*, in fs/nfs Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* [PATCH] nfs: change uses of f_{dentry,vfsmnt} to use f_pathJosef "Jeff" Sipek2006-12-081-1/+1
| | | | | | | | | Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the nfs client code. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* SUNRPC: Make rpc_mkpipe() take the parent dentry as an argumentTrond Myklebust2006-09-221-5/+1
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Share NFS superblocks per-protocol per-server per-FSIDDavid Howells2006-09-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Return an error when starting the idmapping pipeDavid Howells2006-09-221-4/+8
| | | | | | | | 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>
* NFS: Rename struct nfs4_client to struct nfs_clientDavid Howells2006-09-221-6/+6
| | | | | | | | 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>
* NFS: Fix up split of fs/nfs/inode.cDavid Howells2006-09-221-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* SUNRPC: Fix dentry refcounting issues with users of rpc_pipefsTrond Myklebust2006-08-241-1/+0
| | | | | | | rpc_unlink() and rpc_rmdir() will dput the dentry reference for you. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> (cherry picked from a05a57effa71a1f67ccbfc52335c10c8b85f3f6a commit)
OpenPOWER on IntegriCloud