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author | Scott Mayhew <smayhew@redhat.com> | 2017-12-05 13:55:44 -0500 |
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committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2017-12-15 14:31:49 -0500 |
commit | c156618e15101a9cc8c815108fec0300a0ec6637 (patch) | |
tree | aa9384520ea1a224d5be11bfe2614f03580791d0 /lib | |
parent | eb5b46faa693470681ec7c28cc2436edd1571198 (diff) | |
download | linux-stable-c156618e15101a9cc8c815108fec0300a0ec6637.tar.gz linux-stable-c156618e15101a9cc8c815108fec0300a0ec6637.tar.bz2 linux-stable-c156618e15101a9cc8c815108fec0300a0ec6637.zip |
nfs: fix a deadlock in nfs client initialization
The following deadlock can occur between a process waiting for a client
to initialize in while walking the client list during nfsv4 server trunking
detection and another process waiting for the nfs_clid_init_mutex so it
can initialize that client:
Process 1 Process 2
--------- ---------
spin_lock(&nn->nfs_client_lock);
list_add_tail(&CLIENTA->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
spin_lock(&nn->nfs_client_lock);
list_add_tail(&CLIENTB->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
mutex_lock(&nfs_clid_init_mutex);
nfs41_walk_client_list(clp, result, cred);
nfs_wait_client_init_complete(CLIENTA);
(waiting for nfs_clid_init_mutex)
Make sure nfs_match_client() only evaluates clients that have completed
initialization in order to prevent that deadlock.
This patch also fixes v4.0 trunking behavior by not marking the client
NFS_CS_READY until the clientid has been confirmed.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'lib')
0 files changed, 0 insertions, 0 deletions