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author | David Howells <dhowells@redhat.com> | 2019-05-07 15:16:26 +0100 |
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committer | David Howells <dhowells@redhat.com> | 2019-05-15 17:35:53 +0100 |
commit | 6b8812fc8ec28c13c09c89f88ce3958f19238838 (patch) | |
tree | 9cbdfed7205a1b2255706b1293893639b1122ba4 /fs/afs | |
parent | 773e0c40253443e0ce5491cb0e414b62f7cc45ed (diff) | |
download | linux-6b8812fc8ec28c13c09c89f88ce3958f19238838.tar.gz linux-6b8812fc8ec28c13c09c89f88ce3958f19238838.tar.bz2 linux-6b8812fc8ec28c13c09c89f88ce3958f19238838.zip |
afs: Fix missing lock when replacing VL server list
When afs_update_cell() replaces the cell->vl_servers list, it uses RCU
protocol so that proc is protected, but doesn't take ->vl_servers_lock to
protect afs_start_vl_iteration() (which does actually take a shared lock).
Fix this by making afs_update_cell() take an exclusive lock when replacing
->vl_servers.
Fixes: 0a5143f2f89c ("afs: Implement VL server rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs')
-rw-r--r-- | fs/afs/cell.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 9de46116c749..9ca075e11239 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -404,12 +404,11 @@ static void afs_update_cell(struct afs_cell *cell) clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags); clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags); - /* Exclusion on changing vl_addrs is achieved by a - * non-reentrant work item. - */ + write_lock(&cell->vl_servers_lock); old = rcu_dereference_protected(cell->vl_servers, true); rcu_assign_pointer(cell->vl_servers, vllist); cell->dns_expiry = expiry; + write_unlock(&cell->vl_servers_lock); if (old) afs_put_vlserverlist(cell->net, old); |