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authorWeston Andros Adamson <dros@primarydata.com>2014-01-21 15:21:33 -0500
committerTrond Myklebust <trond.myklebust@primarydata.com>2014-01-21 14:12:18 -0700
commit471252cd8b34b0609973740b25dcd1ff01dc1889 (patch)
tree392de168d98cfa7ca804eb1dafbeefd7dc0cdbd9 /fs/nfs
parentabad2fa5ba67725a3f9c376c8cfe76fbe94a3041 (diff)
downloadop-kernel-dev-471252cd8b34b0609973740b25dcd1ff01dc1889.zip
op-kernel-dev-471252cd8b34b0609973740b25dcd1ff01dc1889.tar.gz
pnfs: fix BUG in filelayout_recover_commit_reqs
cond_resched_lock(cinfo->lock) is called everywhere else while holding the cinfo->lock spinlock. Not holding this lock while calling transfer_commit_list in filelayout_recover_commit_reqs causes the BUG below. It's true that we can't hold this lock while calling pnfs_put_lseg, because that might try to lock the inode lock - which might be the same lock as cinfo->lock. To reproduce, mount a 2 DS pynfs server and run an O_DIRECT command that crosses a stripe boundary and is not page aligned, such as: dd if=/dev/zero of=/mnt/f bs=17000 count=1 oflag=direct BUG: sleeping function called from invalid context at linux/fs/nfs/nfs4filelayout.c:1161 in_atomic(): 0, irqs_disabled(): 0, pid: 27, name: kworker/0:1 2 locks held by kworker/0:1/27: #0: (events){.+.+.+}, at: [<ffffffff810501d7>] process_one_work+0x175/0x3a5 #1: ((&dreq->work)){+.+...}, at: [<ffffffff810501d7>] process_one_work+0x175/0x3a5 CPU: 0 PID: 27 Comm: kworker/0:1 Not tainted 3.13.0-rc3-branch-dros_testing+ #21 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Workqueue: events nfs_direct_write_schedule_work [nfs] 0000000000000000 ffff88007a39bbb8 ffffffff81491256 ffff88007b87a130 ffff88007a39bbd8 ffffffff8105f103 ffff880079614000 ffff880079617d40 ffff88007a39bc20 ffffffffa011603e ffff880078988b98 0000000000000000 Call Trace: [<ffffffff81491256>] dump_stack+0x4d/0x66 [<ffffffff8105f103>] __might_sleep+0x100/0x105 [<ffffffffa011603e>] transfer_commit_list+0x94/0xf1 [nfs_layout_nfsv41_files] [<ffffffffa01160d6>] filelayout_recover_commit_reqs+0x3b/0x68 [nfs_layout_nfsv41_files] [<ffffffffa00ba53a>] nfs_direct_write_reschedule+0x9f/0x1d6 [nfs] [<ffffffff810705df>] ? mark_lock+0x1df/0x224 [<ffffffff8106e617>] ? trace_hardirqs_off_caller+0x37/0xa4 [<ffffffff8106e691>] ? trace_hardirqs_off+0xd/0xf [<ffffffffa00ba8f8>] nfs_direct_write_schedule_work+0x9d/0xb7 [nfs] [<ffffffff810501d7>] ? process_one_work+0x175/0x3a5 [<ffffffff81050258>] process_one_work+0x1f6/0x3a5 [<ffffffff810501d7>] ? process_one_work+0x175/0x3a5 [<ffffffff8105187e>] worker_thread+0x149/0x1f5 [<ffffffff81051735>] ? rescuer_thread+0x28d/0x28d [<ffffffff81056d74>] kthread+0xd2/0xda [<ffffffff81056ca2>] ? __kthread_parkme+0x61/0x61 [<ffffffff8149e66c>] ret_from_fork+0x7c/0xb0 [<ffffffff81056ca2>] ? __kthread_parkme+0x61/0x61 Signed-off-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4filelayout.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 0a93e79..03fd8be 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -1216,17 +1216,17 @@ static void filelayout_recover_commit_reqs(struct list_head *dst,
struct pnfs_commit_bucket *b;
int i;
- /* NOTE cinfo->lock is NOT held, relying on fact that this is
- * only called on single thread per dreq.
- * Can't take the lock because need to do pnfs_put_lseg
- */
+ spin_lock(cinfo->lock);
for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
+ spin_unlock(cinfo->lock);
pnfs_put_lseg(b->wlseg);
b->wlseg = NULL;
+ spin_lock(cinfo->lock);
}
}
cinfo->ds->nwritten = 0;
+ spin_unlock(cinfo->lock);
}
static unsigned int
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