FS-Cache: Fix operation state management and accounting

[karo-tx-linux.git] / include / linux / fscache-cache.h

diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index e3d6d939d959f2446908502491ed0b868a1a6a89..f5facd1d333f3fdbbfd0646105c6863f1d18bd94 100644 (file)
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -75,6 +75,16 @@ extern wait_queue_head_t fscache_cache_cleared_wq;
 typedef void (*fscache_operation_release_t)(struct fscache_operation *op);
 typedef void (*fscache_operation_processor_t)(struct fscache_operation *op);
 
+enum fscache_operation_state {
+       FSCACHE_OP_ST_BLANK,            /* Op is not yet submitted */
+       FSCACHE_OP_ST_INITIALISED,      /* Op is initialised */
+       FSCACHE_OP_ST_PENDING,          /* Op is blocked from running */
+       FSCACHE_OP_ST_IN_PROGRESS,      /* Op is in progress */
+       FSCACHE_OP_ST_COMPLETE,         /* Op is complete */
+       FSCACHE_OP_ST_CANCELLED,        /* Op has been cancelled */
+       FSCACHE_OP_ST_DEAD              /* Op is now dead */
+};
+
 struct fscache_operation {
        struct work_struct      work;           /* record for async ops */
        struct list_head        pend_link;      /* link in object->pending_ops */
@@ -86,10 +96,10 @@ struct fscache_operation {
 #define FSCACHE_OP_MYTHREAD    0x0002  /* - processing is done be issuing thread, not pool */
 #define FSCACHE_OP_WAITING     4       /* cleared when op is woken */
 #define FSCACHE_OP_EXCLUSIVE   5       /* exclusive op, other ops must wait */
-#define FSCACHE_OP_DEAD                6       /* op is now dead */
-#define FSCACHE_OP_DEC_READ_CNT        7       /* decrement object->n_reads on destruction */
-#define FSCACHE_OP_KEEP_FLAGS  0xc0    /* flags to keep when repurposing an op */
+#define FSCACHE_OP_DEC_READ_CNT        6       /* decrement object->n_reads on destruction */
+#define FSCACHE_OP_KEEP_FLAGS  0x0070  /* flags to keep when repurposing an op */
 
+       enum fscache_operation_state state;
        atomic_t                usage;
        unsigned                debug_id;       /* debugging ID */
 
@@ -106,6 +116,7 @@ extern atomic_t fscache_op_debug_id;
 extern void fscache_op_work_func(struct work_struct *work);
 
 extern void fscache_enqueue_operation(struct fscache_operation *);
+extern void fscache_op_complete(struct fscache_operation *);
 extern void fscache_put_operation(struct fscache_operation *);
 
 /**
@@ -122,6 +133,7 @@ static inline void fscache_operation_init(struct fscache_operation *op,
 {
        INIT_WORK(&op->work, fscache_op_work_func);
        atomic_set(&op->usage, 1);
+       op->state = FSCACHE_OP_ST_INITIALISED;
        op->debug_id = atomic_inc_return(&fscache_op_debug_id);
        op->processor = processor;
        op->release = release;
@@ -138,6 +150,7 @@ struct fscache_retrieval {
        void                    *context;       /* netfs read context (pinned) */
        struct list_head        to_do;          /* list of things to be done by the backend */
        unsigned long           start_time;     /* time at which retrieval started */
+       unsigned                n_pages;        /* number of pages to be retrieved */
 };
 
 typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op,
@@ -173,9 +186,23 @@ static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op)
        fscache_enqueue_operation(&op->op);
 }
 
+/**
+ * fscache_retrieval_complete - Record (partial) completion of a retrieval
+ * @op: The retrieval operation affected
+ * @n_pages: The number of pages to account for
+ */
+static inline void fscache_retrieval_complete(struct fscache_retrieval *op,
+                                             int n_pages)
+{
+       op->n_pages -= n_pages;
+       if (op->n_pages <= 0)
+               fscache_op_complete(&op->op);
+}
+
 /**
  * fscache_put_retrieval - Drop a reference to a retrieval operation
  * @op: The retrieval operation affected
+ * @n_pages: The number of pages to account for
  *
  * Drop a reference to a retrieval operation.
  */
@@ -333,10 +360,10 @@ struct fscache_object {
 
        int                     debug_id;       /* debugging ID */
        int                     n_children;     /* number of child objects */
-       int                     n_ops;          /* number of ops outstanding on object */
+       int                     n_ops;          /* number of extant ops on object */
        int                     n_obj_ops;      /* number of object ops outstanding on object */
        int                     n_in_progress;  /* number of ops in progress */
-       int                     n_exclusive;    /* number of exclusive ops queued */
+       int                     n_exclusive;    /* number of exclusive ops queued or in progress */
        atomic_t                n_reads;        /* number of read ops in progress */
        spinlock_t              lock;           /* state and operations lock */