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Diffstat (limited to 'fs/fscache/operation.c')
-rw-r--r--fs/fscache/operation.c140
1 files changed, 108 insertions, 32 deletions
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index 30afdfa7aec..762a9ec4ffa 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -37,6 +37,7 @@ void fscache_enqueue_operation(struct fscache_operation *op)
ASSERT(op->processor != NULL);
ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
ASSERTCMP(atomic_read(&op->usage), >, 0);
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_IN_PROGRESS);
fscache_stat(&fscache_n_op_enqueue);
switch (op->flags & FSCACHE_OP_TYPE) {
@@ -64,6 +65,9 @@ EXPORT_SYMBOL(fscache_enqueue_operation);
static void fscache_run_op(struct fscache_object *object,
struct fscache_operation *op)
{
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);
+
+ op->state = FSCACHE_OP_ST_IN_PROGRESS;
object->n_in_progress++;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
@@ -84,18 +88,21 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
+ ASSERTCMP(atomic_read(&op->usage), >, 0);
+
spin_lock(&object->lock);
ASSERTCMP(object->n_ops, >=, object->n_in_progress);
ASSERTCMP(object->n_ops, >=, object->n_exclusive);
ASSERT(list_empty(&op->pend_link));
- ret = -ENOBUFS;
+ op->state = FSCACHE_OP_ST_PENDING;
if (fscache_object_is_active(object)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
- if (object->n_ops > 1) {
+ if (object->n_in_progress > 0) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
@@ -121,8 +128,11 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else {
- /* not allowed to submit ops in any other state */
- BUG();
+ /* If we're in any other state, there must have been an I/O
+ * error of some nature.
+ */
+ ASSERT(test_bit(FSCACHE_IOERROR, &object->cache->flags));
+ ret = -EIO;
}
spin_unlock(&object->lock);
@@ -186,6 +196,7 @@ int fscache_submit_op(struct fscache_object *object,
_enter("{OBJ%x OP%x},{%u}",
object->debug_id, op->debug_id, atomic_read(&op->usage));
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
@@ -196,6 +207,7 @@ int fscache_submit_op(struct fscache_object *object,
ostate = object->state;
smp_rmb();
+ op->state = FSCACHE_OP_ST_PENDING;
if (fscache_object_is_active(object)) {
op->object = object;
object->n_ops++;
@@ -225,12 +237,15 @@ int fscache_submit_op(struct fscache_object *object,
object->state == FSCACHE_OBJECT_LC_DYING ||
object->state == FSCACHE_OBJECT_WITHDRAWING) {
fscache_stat(&fscache_n_op_rejected);
+ op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (!test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
fscache_report_unexpected_submission(object, op, ostate);
ASSERT(!fscache_object_is_active(object));
+ op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else {
+ op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
}
@@ -283,20 +298,28 @@ void fscache_start_operations(struct fscache_object *object)
/*
* cancel an operation that's pending on an object
*/
-int fscache_cancel_op(struct fscache_operation *op)
+int fscache_cancel_op(struct fscache_operation *op,
+ void (*do_cancel)(struct fscache_operation *))
{
struct fscache_object *object = op->object;
int ret;
_enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
+ ASSERTCMP(op->state, >=, FSCACHE_OP_ST_PENDING);
+ ASSERTCMP(op->state, !=, FSCACHE_OP_ST_CANCELLED);
+ ASSERTCMP(atomic_read(&op->usage), >, 0);
+
spin_lock(&object->lock);
ret = -EBUSY;
- if (!list_empty(&op->pend_link)) {
+ if (op->state == FSCACHE_OP_ST_PENDING) {
+ ASSERT(!list_empty(&op->pend_link));
fscache_stat(&fscache_n_op_cancelled);
list_del_init(&op->pend_link);
- object->n_ops--;
+ if (do_cancel)
+ do_cancel(op);
+ op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
@@ -311,6 +334,70 @@ int fscache_cancel_op(struct fscache_operation *op)
}
/*
+ * Cancel all pending operations on an object
+ */
+void fscache_cancel_all_ops(struct fscache_object *object)
+{
+ struct fscache_operation *op;
+
+ _enter("OBJ%x", object->debug_id);
+
+ spin_lock(&object->lock);
+
+ while (!list_empty(&object->pending_ops)) {
+ op = list_entry(object->pending_ops.next,
+ struct fscache_operation, pend_link);
+ fscache_stat(&fscache_n_op_cancelled);
+ list_del_init(&op->pend_link);
+
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);
+ op->state = FSCACHE_OP_ST_CANCELLED;
+
+ if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
+ object->n_exclusive--;
+ if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
+ wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
+ fscache_put_operation(op);
+ cond_resched_lock(&object->lock);
+ }
+
+ spin_unlock(&object->lock);
+ _leave("");
+}
+
+/*
+ * Record the completion or cancellation of an in-progress operation.
+ */
+void fscache_op_complete(struct fscache_operation *op, bool cancelled)
+{
+ struct fscache_object *object = op->object;
+
+ _enter("OBJ%x", object->debug_id);
+
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_IN_PROGRESS);
+ ASSERTCMP(object->n_in_progress, >, 0);
+ ASSERTIFCMP(test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags),
+ object->n_exclusive, >, 0);
+ ASSERTIFCMP(test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags),
+ object->n_in_progress, ==, 1);
+
+ spin_lock(&object->lock);
+
+ op->state = cancelled ?
+ FSCACHE_OP_ST_CANCELLED : FSCACHE_OP_ST_COMPLETE;
+
+ if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
+ object->n_exclusive--;
+ object->n_in_progress--;
+ if (object->n_in_progress == 0)
+ fscache_start_operations(object);
+
+ spin_unlock(&object->lock);
+ _leave("");
+}
+EXPORT_SYMBOL(fscache_op_complete);
+
+/*
* release an operation
* - queues pending ops if this is the last in-progress op
*/
@@ -328,8 +415,9 @@ void fscache_put_operation(struct fscache_operation *op)
return;
_debug("PUT OP");
- if (test_and_set_bit(FSCACHE_OP_DEAD, &op->flags))
- BUG();
+ ASSERTIFCMP(op->state != FSCACHE_OP_ST_COMPLETE,
+ op->state, ==, FSCACHE_OP_ST_CANCELLED);
+ op->state = FSCACHE_OP_ST_DEAD;
fscache_stat(&fscache_n_op_release);
@@ -340,8 +428,14 @@ void fscache_put_operation(struct fscache_operation *op)
object = op->object;
- if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
- atomic_dec(&object->n_reads);
+ if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags)) {
+ if (atomic_dec_and_test(&object->n_reads)) {
+ clear_bit(FSCACHE_COOKIE_WAITING_ON_READS,
+ &object->cookie->flags);
+ wake_up_bit(&object->cookie->flags,
+ FSCACHE_COOKIE_WAITING_ON_READS);
+ }
+ }
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
@@ -359,16 +453,6 @@ void fscache_put_operation(struct fscache_operation *op)
return;
}
- if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
- ASSERTCMP(object->n_exclusive, >, 0);
- object->n_exclusive--;
- }
-
- ASSERTCMP(object->n_in_progress, >, 0);
- object->n_in_progress--;
- if (object->n_in_progress == 0)
- fscache_start_operations(object);
-
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
if (object->n_ops == 0)
@@ -407,23 +491,14 @@ void fscache_operation_gc(struct work_struct *work)
spin_unlock(&cache->op_gc_list_lock);
object = op->object;
+ spin_lock(&object->lock);
_debug("GC DEFERRED REL OBJ%x OP%x",
object->debug_id, op->debug_id);
fscache_stat(&fscache_n_op_gc);
ASSERTCMP(atomic_read(&op->usage), ==, 0);
-
- spin_lock(&object->lock);
- if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
- ASSERTCMP(object->n_exclusive, >, 0);
- object->n_exclusive--;
- }
-
- ASSERTCMP(object->n_in_progress, >, 0);
- object->n_in_progress--;
- if (object->n_in_progress == 0)
- fscache_start_operations(object);
+ ASSERTCMP(op->state, ==, FSCACHE_OP_ST_DEAD);
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
@@ -431,6 +506,7 @@ void fscache_operation_gc(struct work_struct *work)
fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&object->lock);
+ kfree(op);
} while (count++ < 20);