7 files changed, 164 insertions, 50 deletions

diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt
index 382d52cdaf2d..f4769b9399df 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.txt
@@ -419,7 +419,10 @@ performed on the denizens of the cache.  These are held in a structure of type:
 
      If an I/O error occurs, fscache_io_error() should be called and -ENOBUFS
      returned if possible or fscache_end_io() called with a suitable error
-     code..
+     code.
+
+     fscache_put_retrieval() should be called after a page or pages are dealt
+     with.  This will complete the operation when all pages are dealt with.
 
 
  (*) Request pages be read from cache [mandatory]:
@@ -526,6 +529,27 @@ FS-Cache provides some utilities that a cache backend may make use of:
      error value should be 0 if successful and an error otherwise.
 
 
+ (*) Record that one or more pages being retrieved or allocated have been dealt
+     with:
+
+        void fscache_retrieval_complete(struct fscache_retrieval *op,
+                                        int n_pages);
+
+     This is called to record the fact that one or more pages have been dealt
+     with and are no longer the concern of this operation.  When the number of
+     pages remaining in the operation reaches 0, the operation will be
+     completed.
+
+
+ (*) Record operation completion:
+
+        void fscache_op_complete(struct fscache_operation *op);
+
+     This is called to record the completion of an operation.  This deducts
+     this operation from the parent object's run state, potentially permitting
+     one or more pending operations to start running.
+
+
  (*) Set highest store limit:
 
         void fscache_set_store_limit(struct fscache_object *object,
diff --git a/Documentation/filesystems/caching/operations.txt b/Documentation/filesystems/caching/operations.txt
index b6b070c57cbf..bee2a5f93d60 100644
--- a/Documentation/filesystems/caching/operations.txt
+++ b/Documentation/filesystems/caching/operations.txt
@@ -174,7 +174,7 @@ Operations are used through the following procedure:
      necessary (the object might have died whilst the thread was waiting).
 
      When it has finished doing its processing, it should call
-     fscache_put_operation() on it.
+     fscache_op_complete() and fscache_put_operation() on it.
 
  (4) The operation holds an effective lock upon the object, preventing other
      exclusive ops conflicting until it is released.  The operation can be
diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index bf123d9c3206..93a0815e0498 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -197,6 +197,7 @@ static void cachefiles_read_copier(struct fscache_operation *_op)
 
                 fscache_end_io(op, monitor->netfs_page, error);
                 page_cache_release(monitor->netfs_page);
+                fscache_retrieval_complete(op, 1);
                 fscache_put_retrieval(op);
                 kfree(monitor);
 
@@ -339,6 +340,7 @@ backing_page_already_uptodate:
 
         copy_highpage(netpage, backpage);
         fscache_end_io(op, netpage, 0);
+        fscache_retrieval_complete(op, 1);
 
 success:
         _debug("success");
@@ -360,6 +362,7 @@ read_error:
                 goto out;
 io_error:
         cachefiles_io_error_obj(object, "Page read error on backing file");
+        fscache_retrieval_complete(op, 1);
         ret = -ENOBUFS;
         goto out;
 
@@ -369,6 +372,7 @@ nomem_monitor:
         fscache_put_retrieval(monitor->op);
         kfree(monitor);
 nomem:
+        fscache_retrieval_complete(op, 1);
         _leave(" = -ENOMEM");
         return -ENOMEM;
 }
@@ -407,7 +411,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
         _enter("{%p},{%lx},,,", object, page->index);
 
         if (!object->backer)
-                return -ENOBUFS;
+                goto enobufs;
 
         inode = object->backer->d_inode;
         ASSERT(S_ISREG(inode->i_mode));
@@ -416,7 +420,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 
         /* calculate the shift required to use bmap */
         if (inode->i_sb->s_blocksize > PAGE_SIZE)
-                return -ENOBUFS;
+                goto enobufs;
 
         shift = PAGE_SHIFT - inode->i_sb->s_blocksize_bits;
 
@@ -448,13 +452,19 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
         } else if (cachefiles_has_space(cache, 0, 1) == 0) {
                 /* there's space in the cache we can use */
                 fscache_mark_page_cached(op, page);
+                fscache_retrieval_complete(op, 1);
                 ret = -ENODATA;
         } else {
-                ret = -ENOBUFS;
+                goto enobufs;
         }
 
         _leave(" = %d", ret);
         return ret;
+
+enobufs:
+        fscache_retrieval_complete(op, 1);
+        _leave(" = -ENOBUFS");
+        return -ENOBUFS;
 }
 
 /*
@@ -632,6 +642,7 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
 
                 /* the netpage is unlocked and marked up to date here */
                 fscache_end_io(op, netpage, 0);
+                fscache_retrieval_complete(op, 1);
                 page_cache_release(netpage);
                 netpage = NULL;
                 continue;
@@ -659,6 +670,7 @@ out:
         list_for_each_entry_safe(netpage, _n, list, lru) {
                 list_del(&netpage->lru);
                 page_cache_release(netpage);
+                fscache_retrieval_complete(op, 1);
         }
 
         _leave(" = %d", ret);
@@ -707,7 +719,7 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
                *nr_pages);
 
         if (!object->backer)
-                return -ENOBUFS;
+                goto all_enobufs;
 
         space = 1;
         if (cachefiles_has_space(cache, 0, *nr_pages) < 0)
@@ -720,7 +732,7 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 
         /* calculate the shift required to use bmap */
         if (inode->i_sb->s_blocksize > PAGE_SIZE)
-                return -ENOBUFS;
+                goto all_enobufs;
 
         shift = PAGE_SHIFT - inode->i_sb->s_blocksize_bits;
 
@@ -760,7 +772,10 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
                         nrbackpages++;
                 } else if (space && pagevec_add(&pagevec, page) == 0) {
                         fscache_mark_pages_cached(op, &pagevec);
+                        fscache_retrieval_complete(op, 1);
                         ret = -ENODATA;
+                } else {
+                        fscache_retrieval_complete(op, 1);
                 }
         }
 
@@ -781,6 +796,10 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
         _leave(" = %d [nr=%u%s]",
                ret, *nr_pages, list_empty(pages) ? " empty" : "");
         return ret;
+
+all_enobufs:
+        fscache_retrieval_complete(op, *nr_pages);
+        return -ENOBUFS;
 }
 
 /*
@@ -815,6 +834,7 @@ int cachefiles_allocate_page(struct fscache_retrieval *op,
         else
                 ret = -ENOBUFS;
 
+        fscache_retrieval_complete(op, 1);
         _leave(" = %d", ret);
         return ret;
 }
@@ -864,6 +884,7 @@ int cachefiles_allocate_pages(struct fscache_retrieval *op,
                 ret = -ENOBUFS;
         }
 
+        fscache_retrieval_complete(op, *nr_pages);
         _leave(" = %d", ret);
         return ret;
 }
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index b6b897c550ac..773bc798a416 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -587,8 +587,6 @@ static void fscache_object_available(struct fscache_object *object)
         if (object->n_in_progress == 0) {
                 if (object->n_ops > 0) {
                         ASSERTCMP(object->n_ops, >=, object->n_obj_ops);
-                        ASSERTIF(object->n_ops > object->n_obj_ops,
-                                 !list_empty(&object->pending_ops));
                         fscache_start_operations(object);
                 } else {
                         ASSERT(list_empty(&object->pending_ops));
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index c857ab824d6e..748f9553c2cb 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);
@@ -80,22 +84,23 @@ static void fscache_run_op(struct fscache_object *object,
 int fscache_submit_exclusive_op(struct fscache_object *object,
                                 struct fscache_operation *op)
 {
-        int ret;
-
         _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);
@@ -111,7 +116,6 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
 
                 /* need to issue a new write op after this */
                 clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
-                ret = 0;
         } else if (object->state == FSCACHE_OBJECT_CREATING) {
                 op->object = object;
                 object->n_ops++;
@@ -119,14 +123,13 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
                 atomic_inc(&op->usage);
                 list_add_tail(&op->pend_link, &object->pending_ops);
                 fscache_stat(&fscache_n_op_pend);
-                ret = 0;
         } else {
                 /* not allowed to submit ops in any other state */
                 BUG();
         }
 
         spin_unlock(&object->lock);
-        return ret;
+        return 0;
 }
 
 /*
@@ -186,6 +189,7 @@ 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 +200,7 @@ 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 +230,15 @@ 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;
         }
 
@@ -290,13 +298,18 @@ int fscache_cancel_op(struct fscache_operation *op)
 
         _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--;
+                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 +324,37 @@ int fscache_cancel_op(struct fscache_operation *op)
 }
 
 /*
+ * Record the completion of an in-progress operation.
+ */
+void fscache_op_complete(struct fscache_operation *op)
+{
+        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 = 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 +372,9 @@ 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);
 
@@ -365,16 +410,6 @@ 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)
@@ -413,23 +448,14 @@ 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--;
@@ -437,6 +463,7 @@ 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);
 
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 248a12e22532..b38b13d2a555 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -162,6 +162,7 @@ static void fscache_attr_changed_op(struct fscache_operation *op)
                         fscache_abort_object(object);
         }
 
+        fscache_op_complete(op);
         _leave("");
 }
 
@@ -223,6 +224,8 @@ static void fscache_release_retrieval_op(struct fscache_operation *_op)
 
         _enter("{OP%x}", op->op.debug_id);
 
+        ASSERTCMP(op->n_pages, ==, 0);
+
         fscache_hist(fscache_retrieval_histogram, op->start_time);
         if (op->context)
                 fscache_put_context(op->op.object->cookie, op->context);
@@ -320,6 +323,11 @@ static int fscache_wait_for_retrieval_activation(struct fscache_object *object,
         _debug("<<< GO");
 
 check_if_dead:
+        if (op->op.state == FSCACHE_OP_ST_CANCELLED) {
+                fscache_stat(stat_object_dead);
+                _leave(" = -ENOBUFS [cancelled]");
+                return -ENOBUFS;
+        }
         if (unlikely(fscache_object_is_dead(object))) {
                 fscache_stat(stat_object_dead);
                 return -ENOBUFS;
@@ -364,6 +372,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
                 _leave(" = -ENOMEM");
                 return -ENOMEM;
         }
+        op->n_pages = 1;
 
         spin_lock(&cookie->lock);
 
@@ -375,10 +384,10 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
         ASSERTCMP(object->state, >, FSCACHE_OBJECT_LOOKING_UP);
 
         atomic_inc(&object->n_reads);
-        set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
+        __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
 
         if (fscache_submit_op(object, &op->op) < 0)
-                goto nobufs_unlock;
+                goto nobufs_unlock_dec;
         spin_unlock(&cookie->lock);
 
         fscache_stat(&fscache_n_retrieval_ops);
@@ -425,6 +434,8 @@ error:
         _leave(" = %d", ret);
         return ret;
 
+nobufs_unlock_dec:
+        atomic_dec(&object->n_reads);
 nobufs_unlock:
         spin_unlock(&cookie->lock);
         kfree(op);
@@ -482,6 +493,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
         op = fscache_alloc_retrieval(mapping, end_io_func, context);
         if (!op)
                 return -ENOMEM;
+        op->n_pages = *nr_pages;
 
         spin_lock(&cookie->lock);
 
@@ -491,10 +503,10 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
                              struct fscache_object, cookie_link);
 
         atomic_inc(&object->n_reads);
-        set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
+        __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
 
         if (fscache_submit_op(object, &op->op) < 0)
-                goto nobufs_unlock;
+                goto nobufs_unlock_dec;
         spin_unlock(&cookie->lock);
 
         fscache_stat(&fscache_n_retrieval_ops);
@@ -541,6 +553,8 @@ error:
         _leave(" = %d", ret);
         return ret;
 
+nobufs_unlock_dec:
+        atomic_dec(&object->n_reads);
 nobufs_unlock:
         spin_unlock(&cookie->lock);
         kfree(op);
@@ -583,6 +597,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
         op = fscache_alloc_retrieval(page->mapping, NULL, NULL);
         if (!op)
                 return -ENOMEM;
+        op->n_pages = 1;
 
         spin_lock(&cookie->lock);
 
@@ -696,6 +711,7 @@ static void fscache_write_op(struct fscache_operation *_op)
         fscache_end_page_write(object, page);
         if (ret < 0) {
                 fscache_abort_object(object);
+                fscache_op_complete(&op->op);
         } else {
                 fscache_enqueue_operation(&op->op);
         }
@@ -710,6 +726,7 @@ superseded:
         spin_unlock(&cookie->stores_lock);
         clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
         spin_unlock(&object->lock);
+        fscache_op_complete(&op->op);
         _leave("");
 }
 
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index e3d6d939d959..f5facd1d333f 100644
--- 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,
@@ -174,8 +187,22 @@ static inline void fscache_enqueue_retrieval(struct fscache_retrieval *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 */