From: David Howells dhowells@redhat.com
[ Upstream commit 286377f6bdf71568a4cf07104fe44006ae0dba6d ]
When the afs module is removed, one of the things that has to be done is to purge the cell database. afs_cell_purge() cancels the management timer and then starts the cell manager work item to do the purging. This does a single run through and then assumes that all cells are now purged - but this is no longer the case.
With the introduction of alias detection, a later cell in the database can now be holding an active count on an earlier cell (cell->alias_of). The purge scan passes by the earlier cell first, but this can't be got rid of until it has discarded the alias. Ordinarily, afs_unuse_cell() would handle this by setting the management timer to trigger another pass - but afs_set_cell_timer() doesn't do anything if the namespace is being removed (net->live == false). rmmod then hangs in the wait on cells_outstanding in afs_cell_purge().
Fix this by making afs_set_cell_timer() directly queue the cell manager if net->live is false. This causes additional management passes.
Queueing the cell manager increments cells_outstanding to make sure the wait won't complete until all cells are destroyed.
Fixes: 8a070a964877 ("afs: Detect cell aliases 1 - Cells with root volumes") Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/cell.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/afs/cell.c b/fs/afs/cell.c index c906000b0ff84..1944be78e9b0d 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -19,6 +19,7 @@ static unsigned __read_mostly afs_cell_gc_delay = 10; static unsigned __read_mostly afs_cell_min_ttl = 10 * 60; static unsigned __read_mostly afs_cell_max_ttl = 24 * 60 * 60;
+static void afs_queue_cell_manager(struct afs_net *); static void afs_manage_cell_work(struct work_struct *);
static void afs_dec_cells_outstanding(struct afs_net *net) @@ -37,6 +38,8 @@ static void afs_set_cell_timer(struct afs_net *net, time64_t delay) atomic_inc(&net->cells_outstanding); if (timer_reduce(&net->cells_timer, jiffies + delay * HZ)) afs_dec_cells_outstanding(net); + } else { + afs_queue_cell_manager(net); } }