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2013-10-24nfs: use %p[dD] instead of open-coded (and often racy) equivalentsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-08NFS:Add labels to client function prototypesDavid Quigley
After looking at all of the nfsv4 operations the label structure has been added to the prototypes of the functions which can transmit label data. Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com> Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg> Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg> Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg> Signed-off-by: Steve Dickson <steved@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-01-30NFS: Don't silently fail setattr() requests on mountpointsTrond Myklebust
Ensure that any setattr and getattr requests for junctions and/or mountpoints are sent to the server. Ever since commit 0ec26fd0698 (vfs: automount should ignore LOOKUP_FOLLOW), we have silently dropped any setattr requests to a server-side mountpoint. For referrals, we have silently dropped both getattr and setattr requests. This patch restores the original behaviour for setattr on mountpoints, and tries to do the same for referrals, provided that we have a filehandle... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2012-10-31nfs: Show original device name verbatim in /proc/*/mount{s,info}Ben Hutchings
Since commit c7f404b ('vfs: new superblock methods to override /proc/*/mount{s,info}'), nfs_path() is used to generate the mounted device name reported back to userland. nfs_path() always generates a trailing slash when the given dentry is the root of an NFS mount, but userland may expect the original device name to be returned verbatim (as it used to be). Make this canonicalisation optional and change the callers accordingly. [jrnieder@gmail.com: use flag instead of bool argument] Reported-and-tested-by: Chris Hiestand <chiestand@salk.edu> Reference: http://bugs.debian.org/669314 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: <stable@vger.kernel.org> # v2.6.39+ Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30NFS: Convert v4 into a moduleBryan Schumaker
This patch exports symbols needed by the v4 module. In addition, I also switch over to using IS_ENABLED() to check if CONFIG_NFS_V4 or CONFIG_NFS_V4_MODULE are set. The module (nfs4.ko) will be created in the same directory as nfs.ko and will be automatically loaded the first time you try to mount over NFS v4. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30NFS: Convert v2 into a moduleBryan Schumaker
The module (nfs2.ko) will be created in the same directory as nfs.ko and will be automatically loaded the first time you try to mount over NFS v2. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-07-30NFS: Remove the NFS v4 xdev mount functionBryan Schumaker
I can now share this code with the v2 and v3 code by using the NFS subversion structure. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Remove extra rpc_clnt argument to proc_lookupBryan Schumaker
Now that I'm doing secinfo automatically in the v4 code this extra argument isn't needed. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Create a submount rpc_opBryan Schumaker
This simplifies the code for v2 and v3 and gives v4 a chance to decide on referrals without needing to modify the generic client. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Remove secinfo knowledge out of the generic clientBryan Schumaker
And also remove the unneeded rpc_op. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Remove unused function nfs_lookup_with_sec()Bryan Schumaker
This fixes a compiler warning. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Honor the authflavor set in the clone mount dataBryan Schumaker
The authflavor is set in an nfs_clone_mount structure and passed to the xdev_mount() functions where it was promptly ignored. Instead, use it to initialize an rpc_clnt for the cloned server. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-04-27NFS: Fix following referral mount points with different securityBryan Schumaker
I create a new proc_lookup_mountpoint() to use when submounting an NFS v4 share. This function returns an rpc_clnt to use for performing an fs_locations() call on a referral's mountpoint. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-16nfs: Clean up debugging in nfs_follow_mountpoint()Chuck Lever
Clean up: Fix a debugging message which had an obsolete function name in it (nfs_follow_mountpoint). Introduced by commit 36d43a43 "NFS: Use d_automount() rather than abusing follow_link()" (January 14, 2011) Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-07-12NFS: Add SECINFO_NO_NAME procedureBryan Schumaker
If the client is using NFS v4.1, then we can use SECINFO_NO_NAME to find the secflavor for the initial mount. If the server doesn't support SECINFO_NO_NAME then I fall back on the "guess and check" method used for v4.0 mounts. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-04-12NFS: Remove unused argument from nfs_find_best_sec()Bryan Schumaker
The inode was used in an earlier version of the code, but it isn't used anymore. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-04-06NFS: Fix a signed vs. unsigned secinfo bugBryan Schumaker
rpc_authflavor_t is cast from an unsigned int, but the initial code tried to use it as a signed int. I fix this by passing an rpc_authflavor_t pointer around, and returning signed integers from functions. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-27NFS: Don't leak RPC clients in NFSv4 secinfo negotiationTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24NFS: use secinfo when crossing mountpointsBryan Schumaker
A submount may use different security than the parent mount does. We should figure out what sec flavor the submount uses at mount time. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24NFS: lookup supports alternate clientBryan Schumaker
A later patch will need to perform a lookup using an alternate client with a different security flavor. This patch adds support for doing that on NFS v4. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-21nfs: lock() vs unlock() typoDan Carpenter
These should be spin_unlock() instead of spin_lock(). It's a typo. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-16nfs: nfs_do_{ref,sub}mount() superblock argument is redundantAl Viro
It's always equal to dentry->d_sb Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-16nfs: make nfs_path() work without vfsmountAl Viro
part 3: now we have everything to get nfs_path() just by dentry - just follow to (disconnected) root and pick the rest of the thing there. Start killing propagation of struct vfsmount * on the paths that used to bring it to nfs_path(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-15Unexport do_add_mount() and add in follow_automount(), not ->d_automount()David Howells
Unexport do_add_mount() and make ->d_automount() return the vfsmount to be added rather than calling do_add_mount() itself. follow_automount() will then do the addition. This slightly complicates things as ->d_automount() normally wants to add the new vfsmount to an expiration list and start an expiration timer. The problem with that is that the vfsmount will be deleted if it has a refcount of 1 and the timer will not repeat if the expiration list is empty. To this end, we require the vfsmount to be returned from d_automount() with a refcount of (at least) 2. One of these refs will be dropped unconditionally. In addition, follow_automount() must get a 3rd ref around the call to do_add_mount() lest it eat a ref and return an error, leaving the mount we have open to being expired as we would otherwise have only 1 ref on it. d_automount() should also add the the vfsmount to the expiration list (by calling mnt_set_expiry()) and start the expiration timer before returning, if this mechanism is to be used. The vfsmount will be unlinked from the expiration list by follow_automount() if do_add_mount() fails. This patch also fixes the call to do_add_mount() for AFS to propagate the mount flags from the parent vfsmount. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-15NFS: Use d_automount() rather than abusing follow_link()David Howells
Make NFS use the new d_automount() dentry operation rather than abusing follow_link() on directories. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-15Add a dentry op to allow processes to be held during pathwalk transitDavid Howells
Add a dentry op (d_manage) to permit a filesystem to hold a process and make it sleep when it tries to transit away from one of that filesystem's directories during a pathwalk. The operation is keyed off a new dentry flag (DCACHE_MANAGE_TRANSIT). The filesystem is allowed to be selective about which processes it holds and which it permits to continue on or prohibits from transiting from each flagged directory. This will allow autofs to hold up client processes whilst letting its userspace daemon through to maintain the directory or the stuff behind it or mounted upon it. The ->d_manage() dentry operation: int (*d_manage)(struct path *path, bool mounting_here); takes a pointer to the directory about to be transited away from and a flag indicating whether the transit is undertaken by do_add_mount() or do_move_mount() skipping through a pile of filesystems mounted on a mountpoint. It should return 0 if successful and to let the process continue on its way; -EISDIR to prohibit the caller from skipping to overmounted filesystems or automounting, and to use this directory; or some other error code to return to the user. ->d_manage() is called with namespace_sem writelocked if mounting_here is true and no other locks held, so it may sleep. However, if mounting_here is true, it may not initiate or wait for a mount or unmount upon the parameter directory, even if the act is actually performed by userspace. Within fs/namei.c, follow_managed() is extended to check with d_manage() first on each managed directory, before transiting away from it or attempting to automount upon it. follow_down() is renamed follow_down_one() and should only be used where the filesystem deliberately intends to avoid management steps (e.g. autofs). A new follow_down() is added that incorporates the loop done by all other callers of follow_down() (do_add/move_mount(), autofs and NFSD; whilst AFS, NFS and CIFS do use it, their use is removed by converting them to use d_automount()). The new follow_down() calls d_manage() as appropriate. It also takes an extra parameter to indicate if it is being called from mount code (with namespace_sem writelocked) which it passes to d_manage(). follow_down() ignores automount points so that it can be used to mount on them. __follow_mount_rcu() is made to abort rcu-walk mode if it hits a directory with DCACHE_MANAGE_TRANSIT set on the basis that we're probably going to have to sleep. It would be possible to enter d_manage() in rcu-walk mode too, and have that determine whether to abort or not itself. That would allow the autofs daemon to continue on in rcu-walk mode. Note that DCACHE_MANAGE_TRANSIT on a directory should be cleared when it isn't required as every tranist from that directory will cause d_manage() to be invoked. It can always be set again when necessary. ========================== WHAT THIS MEANS FOR AUTOFS ========================== Autofs currently uses the lookup() inode op and the d_revalidate() dentry op to trigger the automounting of indirect mounts, and both of these can be called with i_mutex held. autofs knows that the i_mutex will be held by the caller in lookup(), and so can drop it before invoking the daemon - but this isn't so for d_revalidate(), since the lock is only held on _some_ of the code paths that call it. This means that autofs can't risk dropping i_mutex from its d_revalidate() function before it calls the daemon. The bug could manifest itself as, for example, a process that's trying to validate an automount dentry that gets made to wait because that dentry is expired and needs cleaning up: mkdir S ffffffff8014e05a 0 32580 24956 Call Trace: [<ffffffff885371fd>] :autofs4:autofs4_wait+0x674/0x897 [<ffffffff80127f7d>] avc_has_perm+0x46/0x58 [<ffffffff8009fdcf>] autoremove_wake_function+0x0/0x2e [<ffffffff88537be6>] :autofs4:autofs4_expire_wait+0x41/0x6b [<ffffffff88535cfc>] :autofs4:autofs4_revalidate+0x91/0x149 [<ffffffff80036d96>] __lookup_hash+0xa0/0x12f [<ffffffff80057a2f>] lookup_create+0x46/0x80 [<ffffffff800e6e31>] sys_mkdirat+0x56/0xe4 versus the automount daemon which wants to remove that dentry, but can't because the normal process is holding the i_mutex lock: automount D ffffffff8014e05a 0 32581 1 32561 Call Trace: [<ffffffff80063c3f>] __mutex_lock_slowpath+0x60/0x9b [<ffffffff8000ccf1>] do_path_lookup+0x2ca/0x2f1 [<ffffffff80063c89>] .text.lock.mutex+0xf/0x14 [<ffffffff800e6d55>] do_rmdir+0x77/0xde [<ffffffff8005d229>] tracesys+0x71/0xe0 [<ffffffff8005d28d>] tracesys+0xd5/0xe0 which means that the system is deadlocked. This patch allows autofs to hold up normal processes whilst the daemon goes ahead and does things to the dentry tree behind the automouter point without risking a deadlock as almost no locks are held in d_manage() and none in d_automount(). Signed-off-by: David Howells <dhowells@redhat.com> Was-Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-07fs: dcache remove dcache_lockNick Piggin
dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: Use rename lock and RCU for multi-step operationsNick Piggin
The remaining usages for dcache_lock is to allow atomic, multi-step read-side operations over the directory tree by excluding modifications to the tree. Also, to walk in the leaf->root direction in the tree where we don't have a natural d_lock ordering. This could be accomplished by taking every d_lock, but this would mean a huge number of locks and actually gets very tricky. Solve this instead by using the rename seqlock for multi-step read-side operations, retry in case of a rename so we don't walk up the wrong parent. Concurrent dentry insertions are not serialised against. Concurrent deletes are tricky when walking up the directory: our parent might have been deleted when dropping locks so also need to check and retry for that. We can also use the rename lock in cases where livelock is a worry (and it is introduced in subsequent patch). Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-05-14NFS: Reduce the stack footprint of nfs_follow_mountpoint()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2009-06-22NFS: Fix nfs_path() to always return a '/' at the beginning of the pathTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11switch follow_down()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-07nfs: BUG_ON in nfs_follow_mountpointDenis V. Lunev
Unfortunately, BUG_ON(IS_ROOT(dentry)) can happen inside nfs_follow_mountpoint with NFS running Fedora 8 using a specific setup. https://bugzilla.redhat.com/show_bug.cgi?id=458622 So, the situation should be handled on NFS client gracefully. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Trond Myklebust <Trond.Myklebust@netapp.com> CC: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-10-07nfs: ERR_PTR is expected on failure from nfs_do_clone_mountDenis V. Lunev
Replace NULL with ERR_PTR(-EINVAL). Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-08-01[PATCH] pass struct path * to do_add_mount()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-16nfs: path_{get,put}() cleanupsJan Blunck
Here are some more places where path_{get,put}() can be used instead of dput()/mntput() pair. Signed-off-by: Jan Blunck <jblunck@suse.de> 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>
2008-05-16nfs: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@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>
2008-04-19make nfs_automount_list staticAdrian Bunk
nfs_automount_list can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-02-14Introduce path_put()Jan Blunck
* Add path_put() functions for releasing a reference to the dentry and vfsmount of a struct path in the right order * Switch from path_release(nd) to path_put(&nd->path) * Rename dput_path() to path_put_conditional() [akpm@linux-foundation.org: fix cifs] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14Embed a struct path into struct nameidata instead of nd->{dentry,mnt}Jan Blunck
This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on <dentry,vfsmount> pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-30NFS: Remove the redundant nfs_client->cl_nfsversionTrond Myklebust
We can get the same information from the rpc_ops structure instead. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-09-01NFS: Fix use of cancel_delayed_work_sync in nfs_release_automount_timerTrond Myklebust
Doh! We can't use cancel_delayed_work_sync because we may have been called from an unmount that was being performed by nfs_automount_task. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-08-07NFS: Replace flush_scheduled_work with cancel_work_sync() and friendsTrond Myklebust
This will avoid deadlocks of the form: stack backtrace: [<c0104fda>] show_trace_log_lvl+0x1a/0x30 [<c0105c02>] show_trace+0x12/0x20 [<c0105d15>] dump_stack+0x15/0x20 [<c013ee42>] __lock_acquire+0xc22/0x1030 [<c013f2b1>] lock_acquire+0x61/0x80 [<c012edd9>] flush_workqueue+0x49/0x70 [<c012ee0d>] flush_scheduled_work+0xd/0x10 [<dcf55c0c>] nfs_release_automount_timer+0x2c/0x30 [nfs] [<dcf45d8e>] nfs_free_server+0x9e/0xd0 [nfs] [<dcf4e626>] nfs_kill_super+0x16/0x20 [nfs] [<c017b38d>] deactivate_super+0x7d/0xa0 [<c018f94b>] mntput_no_expire+0x4b/0x80 [<c018fd94>] expire_mount_list+0xe4/0x140 [<c0191219>] mark_mounts_for_expiry+0x99/0xb0 [<dcf55d1d>] nfs_expire_automounts+0xd/0x40 [nfs] [<c012e61b>] run_workqueue+0x12b/0x1e0 [<c012f05b>] worker_thread+0x9b/0x100 [<c0131c72>] kthread+0x42/0x70 [<c0104c0f>] kernel_thread_helper+0x7/0x18 ======================= Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-02-12[PATCH] mark struct inode_operations const 2Arjan van de Ven
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-11-22WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22WorkStruct: Separate delayable and non-delayable events.David Howells
Separate delayable work items from non-delayable work items be splitting them into a separate structure (delayed_work), which incorporates a work_struct and the timer_list removed from work_struct. The work_struct struct is huge, and this limits it's usefulness. On a 64-bit architecture it's nearly 100 bytes in size. This reduces that by half for the non-delayable type of event. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-04Remove all inclusions of <linux/config.h>Dave Jones
kbuild explicitly includes this at build time. Signed-off-by: Dave Jones <davej@redhat.com>
2006-09-27[PATCH] fs/nfs/: make code staticAdrian Bunk
Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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: Move rpc_ops from nfs_server to nfs_clientDavid Howells
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>