FS-Cache: Start processing an object's operations on that object's death

Start processing an object's operations when that object moves into the DYING
state as the object cannot be destroyed until all its outstanding operations
have completed.

Furthermore, make sure that read and allocation operations handle being woken
up on a dead object.  Such events are recorded in the Allocs.abt and
Retrvls.abt statistics as viewable through /proc/fs/fscache/stats.

The code for waiting for object activation for the read and allocation
operations is also extracted into its own function as it is much the same in
all cases, differing only in the stats incremented.

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

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c
index 9e15289eb5c1..05f77caf4a2d 100644
--- a/fs/fscache/stats.c
+++ b/fs/fscache/stats.c
@@ -39,6 +39,7 @@ atomic_t fscache_n_allocs_ok;
 atomic_t fscache_n_allocs_wait;
 atomic_t fscache_n_allocs_nobufs;
 atomic_t fscache_n_allocs_intr;
+atomic_t fscache_n_allocs_object_dead;
 atomic_t fscache_n_alloc_ops;
 atomic_t fscache_n_alloc_op_waits;
 
@@ -49,6 +50,7 @@ atomic_t fscache_n_retrievals_nodata;
 atomic_t fscache_n_retrievals_nobufs;
 atomic_t fscache_n_retrievals_intr;
 atomic_t fscache_n_retrievals_nomem;
+atomic_t fscache_n_retrievals_object_dead;
 atomic_t fscache_n_retrieval_ops;
 atomic_t fscache_n_retrieval_op_waits;
 
@@ -188,9 +190,10 @@ static int fscache_stats_show(struct seq_file *m, void *v)
                    atomic_read(&fscache_n_allocs_wait),
                    atomic_read(&fscache_n_allocs_nobufs),
                    atomic_read(&fscache_n_allocs_intr));
-        seq_printf(m, "Allocs : ops=%u owt=%u\n",
+        seq_printf(m, "Allocs : ops=%u owt=%u abt=%u\n",
                    atomic_read(&fscache_n_alloc_ops),
-                   atomic_read(&fscache_n_alloc_op_waits));
+                   atomic_read(&fscache_n_alloc_op_waits),
+                   atomic_read(&fscache_n_allocs_object_dead));
 
         seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
                    " int=%u oom=%u\n",
@@ -201,9 +204,10 @@ static int fscache_stats_show(struct seq_file *m, void *v)
                    atomic_read(&fscache_n_retrievals_nobufs),
                    atomic_read(&fscache_n_retrievals_intr),
                    atomic_read(&fscache_n_retrievals_nomem));
-        seq_printf(m, "Retrvls: ops=%u owt=%u\n",
+        seq_printf(m, "Retrvls: ops=%u owt=%u abt=%u\n",
                    atomic_read(&fscache_n_retrieval_ops),
-                   atomic_read(&fscache_n_retrieval_op_waits));
+                   atomic_read(&fscache_n_retrieval_op_waits),
+                   atomic_read(&fscache_n_retrievals_object_dead));
 
         seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
                    atomic_read(&fscache_n_stores),