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-rw-r--r--fs/fscache/operation.c120
1 files changed, 92 insertions, 28 deletions
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index e7f8d53..313e79a 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -13,6 +13,7 @@
#define FSCACHE_DEBUG_LEVEL OPERATION
#include <linux/module.h>
+#include <linux/seq_file.h>
#include "internal.h"
atomic_t fscache_op_debug_id;
@@ -31,32 +32,33 @@ void fscache_enqueue_operation(struct fscache_operation *op)
_enter("{OBJ%x OP%x,%u}",
op->object->debug_id, op->debug_id, atomic_read(&op->usage));
+ fscache_set_op_state(op, "EnQ");
+
+ ASSERT(list_empty(&op->pend_link));
ASSERT(op->processor != NULL);
ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
ASSERTCMP(atomic_read(&op->usage), >, 0);
- if (list_empty(&op->pend_link)) {
- switch (op->flags & FSCACHE_OP_TYPE) {
- case FSCACHE_OP_FAST:
- _debug("queue fast");
- atomic_inc(&op->usage);
- if (!schedule_work(&op->fast_work))
- fscache_put_operation(op);
- break;
- case FSCACHE_OP_SLOW:
- _debug("queue slow");
- slow_work_enqueue(&op->slow_work);
- break;
- case FSCACHE_OP_MYTHREAD:
- _debug("queue for caller's attention");
- break;
- default:
- printk(KERN_ERR "FS-Cache: Unexpected op type %lx",
- op->flags);
- BUG();
- break;
- }
- fscache_stat(&fscache_n_op_enqueue);
+ fscache_stat(&fscache_n_op_enqueue);
+ switch (op->flags & FSCACHE_OP_TYPE) {
+ case FSCACHE_OP_FAST:
+ _debug("queue fast");
+ atomic_inc(&op->usage);
+ if (!schedule_work(&op->fast_work))
+ fscache_put_operation(op);
+ break;
+ case FSCACHE_OP_SLOW:
+ _debug("queue slow");
+ slow_work_enqueue(&op->slow_work);
+ break;
+ case FSCACHE_OP_MYTHREAD:
+ _debug("queue for caller's attention");
+ break;
+ default:
+ printk(KERN_ERR "FS-Cache: Unexpected op type %lx",
+ op->flags);
+ BUG();
+ break;
}
}
EXPORT_SYMBOL(fscache_enqueue_operation);
@@ -67,6 +69,8 @@ EXPORT_SYMBOL(fscache_enqueue_operation);
static void fscache_run_op(struct fscache_object *object,
struct fscache_operation *op)
{
+ fscache_set_op_state(op, "Run");
+
object->n_in_progress++;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
@@ -87,9 +91,12 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
+ fscache_set_op_state(op, "SubmitX");
+
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;
if (fscache_object_is_active(object)) {
@@ -190,9 +197,12 @@ int fscache_submit_op(struct fscache_object *object,
ASSERTCMP(atomic_read(&op->usage), >, 0);
+ fscache_set_op_state(op, "Submit");
+
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));
ostate = object->state;
smp_rmb();
@@ -222,6 +232,11 @@ int fscache_submit_op(struct fscache_object *object,
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
+ } else if (object->state == FSCACHE_OBJECT_DYING ||
+ object->state == FSCACHE_OBJECT_LC_DYING ||
+ object->state == FSCACHE_OBJECT_WITHDRAWING) {
+ fscache_stat(&fscache_n_op_rejected);
+ ret = -ENOBUFS;
} else if (!test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
fscache_report_unexpected_submission(object, op, ostate);
ASSERT(!fscache_object_is_active(object));
@@ -264,12 +279,7 @@ void fscache_start_operations(struct fscache_object *object)
stop = true;
}
list_del_init(&op->pend_link);
- object->n_in_progress++;
-
- if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
- wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
- if (op->processor)
- fscache_enqueue_operation(op);
+ fscache_run_op(object, op);
/* the pending queue was holding a ref on the object */
fscache_put_operation(op);
@@ -282,6 +292,36 @@ 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)
+{
+ struct fscache_object *object = op->object;
+ int ret;
+
+ _enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
+
+ spin_lock(&object->lock);
+
+ ret = -EBUSY;
+ if (!list_empty(&op->pend_link)) {
+ fscache_stat(&fscache_n_op_cancelled);
+ list_del_init(&op->pend_link);
+ object->n_ops--;
+ 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);
+ ret = 0;
+ }
+
+ spin_unlock(&object->lock);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
* release an operation
* - queues pending ops if this is the last in-progress op
*/
@@ -298,6 +338,8 @@ void fscache_put_operation(struct fscache_operation *op)
if (!atomic_dec_and_test(&op->usage))
return;
+ fscache_set_op_state(op, "Put");
+
_debug("PUT OP");
if (test_and_set_bit(FSCACHE_OP_DEAD, &op->flags))
BUG();
@@ -311,6 +353,9 @@ 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);
+
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
* lock, and defer it otherwise */
@@ -452,8 +497,27 @@ static void fscache_op_execute(struct slow_work *work)
_leave("");
}
+/*
+ * describe an operation for slow-work debugging
+ */
+#ifdef CONFIG_SLOW_WORK_PROC
+static void fscache_op_desc(struct slow_work *work, struct seq_file *m)
+{
+ struct fscache_operation *op =
+ container_of(work, struct fscache_operation, slow_work);
+
+ seq_printf(m, "FSC: OBJ%x OP%x: %s/%s fl=%lx",
+ op->object->debug_id, op->debug_id,
+ op->name, op->state, op->flags);
+}
+#endif
+
const struct slow_work_ops fscache_op_slow_work_ops = {
+ .owner = THIS_MODULE,
.get_ref = fscache_op_get_ref,
.put_ref = fscache_op_put_ref,
.execute = fscache_op_execute,
+#ifdef CONFIG_SLOW_WORK_PROC
+ .desc = fscache_op_desc,
+#endif
};
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