FS-Cache: Annotate slow-work runqueue proc lines for FS-Cache work items

Annotate slow-work runqueue proc lines for FS-Cache work items.  Objects
include the object ID and the state.  Operations include the object ID, the
operation ID and the operation type and state.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index d236eb1..615b63d 100644 (file)
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -14,9 +14,10 @@
 
 #define FSCACHE_DEBUG_LEVEL COOKIE
 #include <linux/module.h>
+#include <linux/seq_file.h>
 #include "internal.h"
 
-const char *fscache_object_states[] = {
+const char *fscache_object_states[FSCACHE_OBJECT__NSTATES] = {
        [FSCACHE_OBJECT_INIT]           = "OBJECT_INIT",
        [FSCACHE_OBJECT_LOOKING_UP]     = "OBJECT_LOOKING_UP",
        [FSCACHE_OBJECT_CREATING]       = "OBJECT_CREATING",
@@ -33,9 +34,28 @@ const char *fscache_object_states[] = {
 };
 EXPORT_SYMBOL(fscache_object_states);
 
+static const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5] = {
+       [FSCACHE_OBJECT_INIT]           = "INIT",
+       [FSCACHE_OBJECT_LOOKING_UP]     = "LOOK",
+       [FSCACHE_OBJECT_CREATING]       = "CRTN",
+       [FSCACHE_OBJECT_AVAILABLE]      = "AVBL",
+       [FSCACHE_OBJECT_ACTIVE]         = "ACTV",
+       [FSCACHE_OBJECT_UPDATING]       = "UPDT",
+       [FSCACHE_OBJECT_DYING]          = "DYNG",
+       [FSCACHE_OBJECT_LC_DYING]       = "LCDY",
+       [FSCACHE_OBJECT_ABORT_INIT]     = "ABTI",
+       [FSCACHE_OBJECT_RELEASING]      = "RELS",
+       [FSCACHE_OBJECT_RECYCLING]      = "RCYC",
+       [FSCACHE_OBJECT_WITHDRAWING]    = "WTHD",
+       [FSCACHE_OBJECT_DEAD]           = "DEAD",
+};
+
 static void fscache_object_slow_work_put_ref(struct slow_work *);
 static int  fscache_object_slow_work_get_ref(struct slow_work *);
 static void fscache_object_slow_work_execute(struct slow_work *);
+#ifdef CONFIG_SLOW_WORK_PROC
+static void fscache_object_slow_work_desc(struct slow_work *, struct seq_file *);
+#endif
 static void fscache_initialise_object(struct fscache_object *);
 static void fscache_lookup_object(struct fscache_object *);
 static void fscache_object_available(struct fscache_object *);
@@ -49,6 +69,9 @@ const struct slow_work_ops fscache_object_slow_work_ops = {
        .get_ref        = fscache_object_slow_work_get_ref,
        .put_ref        = fscache_object_slow_work_put_ref,
        .execute        = fscache_object_slow_work_execute,
+#ifdef CONFIG_SLOW_WORK_PROC
+       .desc           = fscache_object_slow_work_desc,
+#endif
 };
 EXPORT_SYMBOL(fscache_object_slow_work_ops);
 
@@ -327,6 +350,22 @@ static void fscache_object_slow_work_execute(struct slow_work *work)
 }
 
 /*
+ * describe an object for slow-work debugging
+ */
+#ifdef CONFIG_SLOW_WORK_PROC
+static void fscache_object_slow_work_desc(struct slow_work *work,
+                                         struct seq_file *m)
+{
+       struct fscache_object *object =
+               container_of(work, struct fscache_object, work);
+
+       seq_printf(m, "FSC: OBJ%x: %s",
+                  object->debug_id,
+                  fscache_object_states_short[object->state]);
+}
+#endif
+
+/*
  * initialise an object
  * - check the specified object's parent to see if we can make use of it
  *   immediately to do a creation

diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index f1a2857..91bbe6f 100644 (file)
--- 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;
@@ -31,6 +32,8 @@ 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(op->processor != NULL);
        ASSERTCMP(op->object->state, >=, FSCACHE_OBJECT_AVAILABLE);
        ASSERTCMP(atomic_read(&op->usage), >, 0);
@@ -67,6 +70,8 @@ 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);
@@ -87,6 +92,8 @@ 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);
@@ -190,6 +197,8 @@ 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);
@@ -298,6 +307,8 @@ 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();
@@ -452,9 +463,27 @@ 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
 };

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 2568e0e..e8bbc39 100644 (file)
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -63,14 +63,19 @@ static void fscache_end_page_write(struct fscache_cookie *cookie, struct page *p
 static void fscache_attr_changed_op(struct fscache_operation *op)
 {
        struct fscache_object *object = op->object;
+       int ret;
 
        _enter("{OBJ%x OP%x}", object->debug_id, op->debug_id);
 
        fscache_stat(&fscache_n_attr_changed_calls);
 
-       if (fscache_object_is_active(object) &&
-           object->cache->ops->attr_changed(object) < 0)
-               fscache_abort_object(object);
+       if (fscache_object_is_active(object)) {
+               fscache_set_op_state(op, "CallFS");
+               ret = object->cache->ops->attr_changed(object);
+               fscache_set_op_state(op, "Done");
+               if (ret < 0)
+                       fscache_abort_object(object);
+       }
 
        _leave("");
 }
@@ -99,6 +104,7 @@ int __fscache_attr_changed(struct fscache_cookie *cookie)
        fscache_operation_init(op, NULL);
        fscache_operation_init_slow(op, fscache_attr_changed_op);
        op->flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_EXCLUSIVE);
+       fscache_set_op_name(op, "Attr");
 
        spin_lock(&cookie->lock);
 
@@ -184,6 +190,7 @@ static struct fscache_retrieval *fscache_alloc_retrieval(
        op->start_time  = jiffies;
        INIT_WORK(&op->op.fast_work, fscache_retrieval_work);
        INIT_LIST_HEAD(&op->to_do);
+       fscache_set_op_name(&op->op, "Retr");
        return op;
 }
 
@@ -257,6 +264,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
                _leave(" = -ENOMEM");
                return -ENOMEM;
        }
+       fscache_set_op_name(&op->op, "RetrRA1");
 
        spin_lock(&cookie->lock);
 
@@ -369,6 +377,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
        op = fscache_alloc_retrieval(mapping, end_io_func, context);
        if (!op)
                return -ENOMEM;
+       fscache_set_op_name(&op->op, "RetrRAN");
 
        spin_lock(&cookie->lock);
 
@@ -461,6 +470,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
        op = fscache_alloc_retrieval(page->mapping, NULL, NULL);
        if (!op)
                return -ENOMEM;
+       fscache_set_op_name(&op->op, "RetrAL1");
 
        spin_lock(&cookie->lock);
 
@@ -529,6 +539,8 @@ static void fscache_write_op(struct fscache_operation *_op)
 
        _enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
 
+       fscache_set_op_state(&op->op, "GetPage");
+
        spin_lock(&cookie->lock);
        spin_lock(&object->lock);
 
@@ -559,13 +571,17 @@ static void fscache_write_op(struct fscache_operation *_op)
        spin_unlock(&cookie->lock);
 
        if (page) {
+               fscache_set_op_state(&op->op, "Store");
                ret = object->cache->ops->write_page(op, page);
+               fscache_set_op_state(&op->op, "EndWrite");
                fscache_end_page_write(cookie, page);
                page_cache_release(page);
-               if (ret < 0)
+               if (ret < 0) {
+                       fscache_set_op_state(&op->op, "Abort");
                        fscache_abort_object(object);
-               else
+               } else {
                        fscache_enqueue_operation(&op->op);
+               }
        }
 
        _leave("");
@@ -634,6 +650,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
        fscache_operation_init(&op->op, fscache_release_write_op);
        fscache_operation_init_slow(&op->op, fscache_write_op);
        op->op.flags = FSCACHE_OP_SLOW | (1 << FSCACHE_OP_WAITING);
+       fscache_set_op_name(&op->op, "Write1");
 
        ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM);
        if (ret < 0)

diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 84d3532..7a9847c 100644 (file)
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -102,6 +102,16 @@ struct fscache_operation {
 
        /* operation releaser */
        fscache_operation_release_t release;
+
+#ifdef CONFIG_SLOW_WORK_PROC
+       const char *name;               /* operation name */
+       const char *state;              /* operation state */
+#define fscache_set_op_name(OP, N)     do { (OP)->name  = (N); } while(0)
+#define fscache_set_op_state(OP, S)    do { (OP)->state = (S); } while(0)
+#else
+#define fscache_set_op_name(OP, N)     do { } while(0)
+#define fscache_set_op_state(OP, S)    do { } while(0)
+#endif
 };
 
 extern atomic_t fscache_op_debug_id;
@@ -125,6 +135,7 @@ static inline void fscache_operation_init(struct fscache_operation *op,
        op->debug_id = atomic_inc_return(&fscache_op_debug_id);
        op->release = release;
        INIT_LIST_HEAD(&op->pend_link);
+       fscache_set_op_state(op, "Init");
 }
 
 /**
@@ -337,6 +348,7 @@ struct fscache_object {
                FSCACHE_OBJECT_RECYCLING,       /* retiring object */
                FSCACHE_OBJECT_WITHDRAWING,     /* withdrawing object */
                FSCACHE_OBJECT_DEAD,            /* object is now dead */
+               FSCACHE_OBJECT__NSTATES
        } state;
 
        int                     debug_id;       /* debugging ID */