Messages in this thread Patches in this message | | | Subject | Re: 2.6.34 nfs fsync() deadlock | From | Trond Myklebust <> | Date | Mon, 31 May 2010 11:41:07 -0400 |
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On Mon, 2010-05-31 at 15:41 +0100, Nix wrote: > I just got a deadlock while doing a postgresql 'make check' on an NFSv3 > TCP mount (the server is Linux 2.6.34 as well; the underlying filesystem > is ext4). This testsuite is notable for doing a lot of things in > parallel, each of which is generally doing a lot of fsync()ing. > > /proc/mounts for the filesystem of discourse: > > package.srvr.nix:/usr/src /usr/src nfs rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.14.15,mountvers=3,mountport=50892,mountproto=udp,addr=192.168.14.15 0 0 > > /etc/exports for it on the server: > > /usr/src mutilate(rw,no_root_squash,no_subtree_check,async) > > dmesg:
Can you see if the following 2 attached patches (already sent to stable@kernel.org) suffice to fix the hang?
Cheers Trond From 0b574497e05f62fd49cfe26f1b97e3669525446c Mon Sep 17 00:00:00 2001 From: Trond Myklebust <Trond.Myklebust@netapp.com> Date: Sat, 22 May 2010 11:49:19 -0400 Subject: [PATCH] NFS: Ensure that we mark the inode as dirty if we exit early from commit
commit c5efa5fc91f1f6d1d47e65f39e7ec6d1157c777d upstream
If we exit from nfs_commit_inode() without ensuring that the COMMIT rpc call has been completed, we must re-mark the inode as dirty. Otherwise, future calls to sync_inode() with the WB_SYNC_ALL flag set will fail to ensure that the data is on the disk.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> --- Please apply for 2.6.34 stable series
fs/nfs/write.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 3aea3ca..b8a6d7a 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1386,7 +1386,7 @@ static int nfs_commit_inode(struct inode *inode, int how) int res = 0; if (!nfs_commit_set_lock(NFS_I(inode), may_wait)) - goto out; + goto out_mark_dirty; spin_lock(&inode->i_lock); res = nfs_scan_commit(inode, &head, 0, 0); spin_unlock(&inode->i_lock); @@ -1398,9 +1398,18 @@ static int nfs_commit_inode(struct inode *inode, int how) wait_on_bit(&NFS_I(inode)->flags, NFS_INO_COMMIT, nfs_wait_bit_killable, TASK_KILLABLE); + else + goto out_mark_dirty; } else nfs_commit_clear_lock(NFS_I(inode)); -out: + return res; + /* Note: If we exit without ensuring that the commit is complete, + * we must mark the inode as dirty. Otherwise, future calls to + * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure + * that the data is on the disk. + */ +out_mark_dirty: + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return res; } -- 1.7.0.1 From ec9860a19aecb9ca691156d21af9e1865d9c0a28 Mon Sep 17 00:00:00 2001 From: Trond Myklebust <Trond.Myklebust@netapp.com> Date: Sun, 23 May 2010 14:37:02 -0400 Subject: [PATCH] NFS: Fix another nfs_wb_page() deadlock
commit 0522f6adedd2736cbca3c0e16ca51df668993eee upstream
J.R. Okajima reports that the call to sync_inode() in nfs_wb_page() can deadlock with other writeback flush calls. It boils down to the fact that we cannot ever call writeback_single_inode() while holding a page lock (even if we do set nr_to_write to zero) since another process may already be waiting in the call to do_writepages(), and so will deny us the I_SYNC lock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> --- Please apply to 2.6.34 stable series
fs/nfs/write.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index b8a6d7a..91679e2 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1518,14 +1518,17 @@ int nfs_wb_page(struct inode *inode, struct page *page) }; int ret; - while(PagePrivate(page)) { + for (;;) { wait_on_page_writeback(page); if (clear_page_dirty_for_io(page)) { ret = nfs_writepage_locked(page, &wbc); if (ret < 0) goto out_error; + continue; } - ret = sync_inode(inode, &wbc); + if (!PagePrivate(page)) + break; + ret = nfs_commit_inode(inode, FLUSH_SYNC); if (ret < 0) goto out_error; } -- 1.7.0.1
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