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2010-05-14NFSv4: Fix up the documentation for nfs_do_refmountTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Replace nfsroot on-stack filehandleTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Cleanup file handle allocations in fs/nfs/super.cTrond Myklebust
Use the new helper functions instead of open coding. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Prevent the mount code from looping forever on broken exportsTrond Myklebust
Keep a global count of how many referrals that the current task has traversed on a path lookup. Return ELOOP if the count exceeds MAX_NESTED_LINKS. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs3_proc_getacl() and nfs3_proc_setacl()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs_statfs()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs_setattr()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs4_proc_create()Trond Myklebust
Move the O_EXCL open handling into _nfs4_do_open() where it belongs. Doing so also allows us to reuse the struct fattr from the opendata. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_proc_symlink()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_proc_createTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_rmdirTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs_proc_remove()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs3_proc_readlink()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_link()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs_readdir()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs3_proc_rename() and nfs4_proc_rename()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce stack footprint of nfs_revalidate_inode()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFSv4: Reduce stack footprint of nfs4_proc_access() and nfs3_proc_access()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFSv4: Reduce the stack footprint of nfs4_remote_referral_get_sbTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFSv4: Reduce stack footprint of nfs4_get_root()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_follow_remote_path()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_lookupTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFSv4: Reduce the stack footprint of try_location()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_create_serverTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Reduce the stack footprint of nfs_follow_mountpoint()Trond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFSv4: Eliminate nfs4_path_walk()Trond Myklebust
All we really want is the ability to retrieve the root file handle. We no longer need the ability to walk down the path, since that is now done in nfs_follow_remote_path(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-14NFS: Add helper functions for allocating filehandles and fattr structsTrond Myklebust
NFS Filehandles and struct fattr are really too large to be allocated on the stack. This patch adds in a couple of helper functions to allocate them dynamically instead. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-01NFS: Fix RCU issues in the NFSv4 delegation codeDavid Howells
Fix a number of RCU issues in the NFSv4 delegation code. (1) delegation->cred doesn't need to be RCU protected as it's essentially an invariant refcounted structure. By the time we get to nfs_free_delegation(), the delegation is being released, so no one else should be attempting to use the saved credentials, and they can be cleared. However, since the list of delegations could still be under traversal at this point by such as nfs_client_return_marked_delegations(), the cred should be released in nfs_do_free_delegation() rather than in nfs_free_delegation(). Simply using rcu_assign_pointer() to clear it is insufficient as that doesn't stop the cred from being destroyed, and nor does calling put_rpccred() after call_rcu(), given that the latter is asynchronous. (2) nfs_detach_delegation_locked() and nfs_inode_set_delegation() should use rcu_derefence_protected() because they can only be called if nfs_client::cl_lock is held, and that guards against anyone changing nfsi->delegation under it. Furthermore, the barrier imposed by rcu_dereference() is superfluous, given that the spin_lock() is also a barrier. (3) nfs_detach_delegation_locked() is now passed a pointer to the nfs_client struct so that it can issue lockdep advice based on clp->cl_lock for (2). (4) nfs_inode_return_delegation_noreclaim() and nfs_inode_return_delegation() should use rcu_access_pointer() outside the spinlocked region as they merely examine the pointer and don't follow it, thus rendering unnecessary the need to impose a partial ordering over the one item of interest. These result in an RCU warning like the following: [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- fs/nfs/delegation.c:332 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by mount.nfs4/2281: #0: (&type->s_umount_key#34){+.+...}, at: [<ffffffff810b25b4>] deactivate_super+0x60/0x80 #1: (iprune_sem){+.+...}, at: [<ffffffff810c332a>] invalidate_inodes+0x39/0x13a stack backtrace: Pid: 2281, comm: mount.nfs4 Not tainted 2.6.34-rc1-cachefs #110 Call Trace: [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffffa00b4591>] nfs_inode_return_delegation_noreclaim+0x5b/0xa0 [nfs] [<ffffffffa0095d63>] nfs4_clear_inode+0x11/0x1e [nfs] [<ffffffff810c2d92>] clear_inode+0x9e/0xf8 [<ffffffff810c3028>] dispose_list+0x67/0x10e [<ffffffff810c340d>] invalidate_inodes+0x11c/0x13a [<ffffffff810b1dc1>] generic_shutdown_super+0x42/0xf4 [<ffffffff810b1ebe>] kill_anon_super+0x11/0x4f [<ffffffffa009893c>] nfs4_kill_super+0x3f/0x72 [nfs] [<ffffffff810b25bc>] deactivate_super+0x68/0x80 [<ffffffff810c6744>] mntput_no_expire+0xbb/0xf8 [<ffffffff810c681b>] release_mounts+0x9a/0xb0 [<ffffffff810c689b>] put_mnt_ns+0x6a/0x79 [<ffffffffa00983a1>] nfs_follow_remote_path+0x5a/0x146 [nfs] [<ffffffffa0098334>] ? nfs_do_root_mount+0x82/0x95 [nfs] [<ffffffffa00985a9>] nfs4_try_mount+0x75/0xaf [nfs] [<ffffffffa0098874>] nfs4_get_sb+0x291/0x31a [nfs] [<ffffffff810b2059>] vfs_kern_mount+0xb8/0x177 [<ffffffff810b2176>] do_kern_mount+0x48/0xe8 [<ffffffff810c810b>] do_mount+0x782/0x7f9 [<ffffffff810c8205>] sys_mount+0x83/0xbe [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b Also on: fs/nfs/delegation.c:215 invoked rcu_dereference_check() without protection! [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffffa00b4223>] nfs_inode_set_delegation+0xfe/0x219 [nfs] [<ffffffffa00a9c6f>] nfs4_opendata_to_nfs4_state+0x2c2/0x30d [nfs] [<ffffffffa00aa15d>] nfs4_do_open+0x2a6/0x3a6 [nfs] ... And: fs/nfs/delegation.c:40 invoked rcu_dereference_check() without protection! [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffffa00b3bef>] nfs_free_delegation+0x3d/0x6e [nfs] [<ffffffffa00b3e71>] nfs_do_return_delegation+0x26/0x30 [nfs] [<ffffffffa00b406a>] __nfs_inode_return_delegation+0x1ef/0x1fe [nfs] [<ffffffffa00b448a>] nfs_client_return_marked_delegations+0xc9/0x124 [nfs] ... Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-05-01NFSv4: Fix the locking in nfs_inode_reclaim_delegation()Trond Myklebust
Ensure that we correctly rcu-dereference the delegation itself, and that we protect against removal while we're changing the contents. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-04-29Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6Linus Torvalds
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: nfs: fix memory leak in nfs_get_sb with CONFIG_NFS_V4 nfs: fix some issues in nfs41_proc_reclaim_complete() NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clear NFS: Fix an unstable write data integrity race nfs: testing for null instead of ERR_PTR() NFS: rsize and wsize settings ignored on v4 mounts NFSv4: Don't attempt an atomic open if the file is a mountpoint SUNRPC: Fix a bug in rpcauth_prune_expired
2010-04-28nfs d_revalidate() is too trigger-happy with d_drop()Al Viro
If dentry found stale happens to be a root of disconnected tree, we can't d_drop() it; its d_hash is actually part of s_anon and d_drop() would simply hide it from shrink_dcache_for_umount(), leading to all sorts of fun, including busy inodes on umount and oopsen after that. Bug had been there since at least 2006 (commit c636eb already has it), so it's definitely -stable fodder. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-28nfs: fix memory leak in nfs_get_sb with CONFIG_NFS_V4Xiaotian Feng
With CONFIG_NFS_V4 and data version 4, nfs_get_sb will allocate memory for export_path in nfs4_validate_text_mount_data, so we need to free it then. This is addressed in following kmemleak report: unreferenced object 0xffff88016bf48a50 (size 16): comm "mount.nfs", pid 22567, jiffies 4651574704 (age 175471.200s) hex dump (first 16 bytes): 2f 6f 70 74 2f 77 6f 72 6b 00 6b 6b 6b 6b 6b a5 /opt/work.kkkkk. backtrace: [<ffffffff814b34f9>] kmemleak_alloc+0x60/0xa7 [<ffffffff81102c76>] kmemleak_alloc_recursive.clone.5+0x1b/0x1d [<ffffffff811046b3>] __kmalloc_track_caller+0x18f/0x1b7 [<ffffffff810e1b08>] kstrndup+0x37/0x54 [<ffffffffa0336971>] nfs_parse_devname+0x152/0x204 [nfs] [<ffffffffa0336af3>] nfs4_validate_text_mount_data+0xd0/0xdc [nfs] [<ffffffffa0338deb>] nfs_get_sb+0x325/0x736 [nfs] [<ffffffff81113671>] vfs_kern_mount+0xbd/0x17c [<ffffffff81113798>] do_kern_mount+0x4d/0xed [<ffffffff81129a87>] do_mount+0x787/0x7fe [<ffffffff81129b86>] sys_mount+0x88/0xc2 [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Benny Halevy <bhalevy@panasas.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-28nfs: fix some issues in nfs41_proc_reclaim_complete()Dan Carpenter
The original code passed an ERR_PTR() to rpc_put_task() and instead of returning zero on success it returned -ENOMEM. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-27NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clearTrond Myklebust
Neil Brown reports that he is seeing the BUG_ON(ret == 0) trigger in nfs_page_async_flush. According to the trace in https://bugzilla.novell.com/show_bug.cgi?id=599628 the problem appears to be due to nfs_wb_page() not waiting for the PG_writeback flag to clear. There is a ditto problem in nfs_wb_page_cancel() Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22NFS: Fix an unstable write data integrity raceTrond Myklebust
Commit 2c61be0a9478258f77b66208a0c4b1f5f8161c3c (NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible) exposed a race on file close. In order to ensure correct close-to-open behaviour, we want to wait for all outstanding background commit operations to complete. This patch adds an inode flag that indicates if a commit operation is under way, and provides a mechanism to allow ->write_inode() to wait for its completion if this is a data integrity flush. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22nfs: testing for null instead of ERR_PTR()Dan Carpenter
nfs_path() returns an ERR_PTR(), it doesn't return null. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22NFS: rsize and wsize settings ignored on v4 mountsChuck Lever
NFSv4 mounts ignore the rsize and wsize mount options, and always use the default transfer size for both. This seems to be because all NFSv4 mounts are now cloned, and the cloning logic doesn't copy the rsize and wsize settings from the parent nfs_server. I tested Fedora's 2.6.32.11-99 and it seems to have this problem as well, so I'm guessing that .33, .32, and perhaps older kernels have this issue as well. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: Stable <stable@kernel.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22NFSv4: Don't attempt an atomic open if the file is a mountpointTrond Myklebust
Fix https://bugzilla.kernel.org/show_bug.cgi?id=15789 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-12NFSv4: fix delegated lockingTrond Myklebust
Arnaud Giersch reports that NFSv4 locking is broken when we hold a delegation since commit 8e469ebd6dc32cbaf620e134d79f740bf0ebab79 (NFSv4: Don't allow posix locking against servers that don't support it). According to Arnaud, the lock succeeds the first time he opens the file (since we cannot do a delegated open) but then fails after we start using delegated opens. The following patch fixes it by ensuring that locking behaviour is governed by a per-filesystem capability flag that is initially set, but gets cleared if the server ever returns an OPEN without the NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set. Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-04-09NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptibleTrond Myklebust
We always want to ensure that WRITE and COMMIT completes, whether or not the user presses ^C. Do this by making the call asynchronous, and allowing the user to do an interruptible wait for rpc_task completion. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-09NFS: Fix a race with the new commit codeTrond Myklebust
This patch fixes a race which occurs due to the fact that we release the PG_writeback flag while still holding the nfs_page locked. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-09NFS: Ensure that writeback_single_inode() calls write_inode() when syncingTrond Myklebust
Since writeback_single_inode() checks the inode->i_state flags _before_ it flushes out the data, we need to ensure that the I_DIRTY_DATASYNC flag is already set. Otherwise we risk not seeing a call to write_inode(), which again means that we break fsync() et al... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-09NFS: Fix the mode calculation in nfs_find_open_contextTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-09NFSv4: Fall back to ordinary lookup if nfs4_atomic_open() returns EISDIRTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-04-07Have nfs ->d_revalidate() report errors properlyAl Viro
If nfs atomic open implementation ends up doing open request from ->d_revalidate() codepath and gets an error from server, return that error to caller explicitly and don't bother with lookup_instantiate_filp() at all. ->d_revalidate() can return an error itself just fine... See http://bugzilla.kernel.org/show_bug.cgi?id=15674 http://marc.info/?l=linux-kernel&m=126988782722711&w=2 for original report. Reported-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2010-03-22NFS: don't try to decode GETATTR if DELEGRETURN returned errorJeff Layton
The reply parsing code attempts to decode the GETATTR response even if the DELEGRETURN portion of the compound returned an error. The GETATTR response won't actually exist if that's the case and we're asking the parser to read past the end of the response. This bug is fairly benign. The parser catches this without reading past the end of the response and decode_getfattr returns -EIO. Earlier kernels however had decode_op_hdr using the READ_BUF macro, and this bug would make this printk pop any time the client got an error from a delegreturn: kernel: decode_op_hdr: reply buffer overflowed in line XXXX More recent kernels seem to have replaced this printk with a dprintk. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-03-19NFS: Prevent another deadlock in nfs_release_page()Trond Myklebust
We should not attempt to free the page if __GFP_FS is not set. Otherwise we can deadlock as per http://bugzilla.kernel.org/show_bug.cgi?id=15578 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-03-15NFS: ensure bdi_unregister is called on mount failure.NeilBrown
bdi_unregister is called by nfs_put_super which is only called by generic_shutdown_super if ->s_root is not NULL. So if we error out in a circumstance where we called nfs_bdi_register (i.e. server != NULL) but have not set s_root, then we need to call bdi_unregister explicitly in nfs_get_sb and various other *_get_sb() functions. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-03-11NFS: Avoid a deadlock in nfs_release_pageTrond Myklebust
J.R. Okajima reports the following deadlock: INFO: task kswapd0:305 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kswapd0 D 0000000000000001 0 305 2 0x00000000 ffff88001f21d4f0 0000000000000046 ffff88001fdea680 ffff88001f21c000 ffff88001f21dfd8 ffff88001f21c000 ffff88001f21dfd8 ffff88001f21dfd8 ffff88001fdea040 0000000000014c00 0000000000000001 ffff88001fdea040 Call Trace: [<ffffffff8146155d>] io_schedule+0x4d/0x70 [<ffffffff810d2be5>] sync_page+0x65/0xa0 [<ffffffff81461b12>] __wait_on_bit_lock+0x52/0xb0 [<ffffffff810d2b80>] ? sync_page+0x0/0xa0 [<ffffffff810d2b64>] __lock_page+0x64/0x70 [<ffffffff81070ce0>] ? wake_bit_function+0x0/0x40 [<ffffffff810df1d4>] truncate_inode_pages_range+0x344/0x4a0 [<ffffffff810df340>] truncate_inode_pages+0x10/0x20 [<ffffffff8112cbfe>] generic_delete_inode+0x15e/0x190 [<ffffffff8112cc8d>] generic_drop_inode+0x5d/0x80 [<ffffffff8112bb88>] iput+0x78/0x80 [<ffffffff811bc908>] nfs_dentry_iput+0x38/0x50 [<ffffffff811285f4>] dentry_iput+0x84/0x110 [<ffffffff811286ae>] d_kill+0x2e/0x60 [<ffffffff8112912a>] dput+0x7a/0x170 [<ffffffff8111e925>] path_put+0x15/0x40 [<ffffffff811c3a44>] __put_nfs_open_context+0xa4/0xb0 [<ffffffff811cb5d0>] ? nfs_free_request+0x0/0x50 [<ffffffff811c3b0b>] put_nfs_open_context+0xb/0x10 [<ffffffff811cb5f9>] nfs_free_request+0x29/0x50 [<ffffffff81234b7e>] kref_put+0x8e/0xe0 [<ffffffff811cb594>] nfs_release_request+0x14/0x20 [<ffffffff811cf769>] nfs_find_and_lock_request+0x89/0xa0 [<ffffffff811d1180>] nfs_wb_page+0x80/0x110 [<ffffffff811c0770>] nfs_release_page+0x70/0x90 [<ffffffff810d18ee>] try_to_release_page+0x5e/0x80 [<ffffffff810e1178>] shrink_page_list+0x638/0x860 [<ffffffff810e19de>] shrink_zone+0x63e/0xc40 We can fix this by making the call to put_nfs_open_context() happen when we actually remove the write request from the inode (which is done by the nfsiod thread in this case). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org