diff options
-rw-r--r-- | drivers/staging/lustre/lustre/obdclass/lu_object.c | 58 |
1 files changed, 54 insertions, 4 deletions
diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c index f0e74c6..e031fd2 100644 --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c @@ -1311,6 +1311,7 @@ enum { static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, }; static DEFINE_SPINLOCK(lu_keys_guard); +static atomic_t lu_key_initing_cnt = ATOMIC_INIT(0); /** * Global counter incremented whenever key is registered, unregistered, @@ -1385,6 +1386,19 @@ void lu_context_key_degister(struct lu_context_key *key) ++key_set_version; spin_lock(&lu_keys_guard); key_fini(&lu_shrink_env.le_ctx, key->lct_index); + + /** + * Wait until all transient contexts referencing this key have + * run lu_context_key::lct_fini() method. + */ + while (atomic_read(&key->lct_used) > 1) { + spin_unlock(&lu_keys_guard); + CDEBUG(D_INFO, "lu_context_key_degister: \"%s\" %p, %d\n", + key->lct_owner ? key->lct_owner->name : "", key, + atomic_read(&key->lct_used)); + schedule(); + spin_lock(&lu_keys_guard); + } if (lu_keys[key->lct_index]) { lu_keys[key->lct_index] = NULL; lu_ref_fini(&key->lct_reference); @@ -1510,11 +1524,26 @@ void lu_context_key_quiesce(struct lu_context_key *key) * XXX layering violation. */ cl_env_cache_purge(~0); - key->lct_tags |= LCT_QUIESCENT; /* * XXX memory barrier has to go here. */ spin_lock(&lu_keys_guard); + key->lct_tags |= LCT_QUIESCENT; + + /** + * Wait until all lu_context_key::lct_init() methods + * have completed. + */ + while (atomic_read(&lu_key_initing_cnt) > 0) { + spin_unlock(&lu_keys_guard); + CDEBUG(D_INFO, "lu_context_key_quiesce: \"%s\" %p, %d (%d)\n", + key->lct_owner ? key->lct_owner->name : "", + key, atomic_read(&key->lct_used), + atomic_read(&lu_key_initing_cnt)); + schedule(); + spin_lock(&lu_keys_guard); + } + list_for_each_entry(ctx, &lu_context_remembered, lc_remember) key_fini(ctx, key->lct_index); spin_unlock(&lu_keys_guard); @@ -1546,6 +1575,19 @@ static int keys_fill(struct lu_context *ctx) { unsigned int i; + /* + * A serialisation with lu_context_key_quiesce() is needed, but some + * "key->lct_init()" are calling kernel memory allocation routine and + * can't be called while holding a spin_lock. + * "lu_keys_guard" is held while incrementing "lu_key_initing_cnt" + * to ensure the start of the serialisation. + * An atomic_t variable is still used, in order not to reacquire the + * lock when decrementing the counter. + */ + spin_lock(&lu_keys_guard); + atomic_inc(&lu_key_initing_cnt); + spin_unlock(&lu_keys_guard); + LINVRNT(ctx->lc_value); for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { struct lu_context_key *key; @@ -1563,12 +1605,19 @@ static int keys_fill(struct lu_context *ctx) LINVRNT(key->lct_init); LINVRNT(key->lct_index == i); + LASSERT(key->lct_owner); + if (!(ctx->lc_tags & LCT_NOREF) && + !try_module_get(key->lct_owner)) { + /* module is unloading, skip this key */ + continue; + } + value = key->lct_init(ctx, key); - if (IS_ERR(value)) + if (unlikely(IS_ERR(value))) { + atomic_dec(&lu_key_initing_cnt); return PTR_ERR(value); + } - if (!(ctx->lc_tags & LCT_NOREF)) - try_module_get(key->lct_owner); lu_ref_add_atomic(&key->lct_reference, "ctx", ctx); atomic_inc(&key->lct_used); /* @@ -1582,6 +1631,7 @@ static int keys_fill(struct lu_context *ctx) } ctx->lc_version = key_set_version; } + atomic_dec(&lu_key_initing_cnt); return 0; } |