diff options
Diffstat (limited to 'fs/cachefiles')
| -rw-r--r-- | fs/cachefiles/interface.c | 6 | ||||
| -rw-r--r-- | fs/cachefiles/namei.c | 87 |
2 files changed, 72 insertions, 21 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index 8e67abf0598..9d3c426044a 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -114,8 +114,9 @@ nomem_lookup_data: /* * attempt to look up the nominated node in this cache + * - return -ETIMEDOUT to be scheduled again */ -static void cachefiles_lookup_object(struct fscache_object *_object) +static int cachefiles_lookup_object(struct fscache_object *_object) { struct cachefiles_lookup_data *lookup_data; struct cachefiles_object *parent, *object; @@ -145,13 +146,14 @@ static void cachefiles_lookup_object(struct fscache_object *_object) object->fscache.cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) cachefiles_attr_changed(&object->fscache); - if (ret < 0) { + if (ret < 0 && ret != -ETIMEDOUT) { printk(KERN_WARNING "CacheFiles: Lookup failed error %d\n", ret); fscache_object_lookup_error(&object->fscache); } _leave(" [%d]", ret); + return ret; } /* diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index 00a0cda8f47..14ac4806e29 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -21,12 +21,6 @@ #include <linux/security.h> #include "internal.h" -static int cachefiles_wait_bit(void *flags) -{ - schedule(); - return 0; -} - #define CACHEFILES_KEYBUF_SIZE 512 /* @@ -100,8 +94,8 @@ static noinline void cachefiles_printk_object(struct cachefiles_object *object, /* * record the fact that an object is now active */ -static void cachefiles_mark_object_active(struct cachefiles_cache *cache, - struct cachefiles_object *object) +static int cachefiles_mark_object_active(struct cachefiles_cache *cache, + struct cachefiles_object *object) { struct cachefiles_object *xobject; struct rb_node **_p, *_parent = NULL; @@ -139,8 +133,8 @@ try_again: rb_insert_color(&object->active_node, &cache->active_nodes); write_unlock(&cache->active_lock); - _leave(""); - return; + _leave(" = 0"); + return 0; /* an old object from a previous incarnation is hogging the slot - we * need to wait for it to be destroyed */ @@ -155,13 +149,64 @@ wait_for_old_object: atomic_inc(&xobject->usage); write_unlock(&cache->active_lock); - _debug(">>> wait"); - wait_on_bit(&xobject->flags, CACHEFILES_OBJECT_ACTIVE, - cachefiles_wait_bit, TASK_UNINTERRUPTIBLE); - _debug("<<< waited"); + if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { + wait_queue_head_t *wq; + + signed long timeout = 60 * HZ; + wait_queue_t wait; + bool requeue; + + /* if the object we're waiting for is queued for processing, + * then just put ourselves on the queue behind it */ + if (slow_work_is_queued(&xobject->fscache.work)) { + _debug("queue OBJ%x behind OBJ%x immediately", + object->fscache.debug_id, + xobject->fscache.debug_id); + goto requeue; + } + + /* otherwise we sleep until either the object we're waiting for + * is done, or the slow-work facility wants the thread back to + * do other work */ + wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE); + init_wait(&wait); + requeue = false; + do { + prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); + if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) + break; + requeue = slow_work_sleep_till_thread_needed( + &object->fscache.work, &timeout); + } while (timeout > 0 && !requeue); + finish_wait(wq, &wait); + + if (requeue && + test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { + _debug("queue OBJ%x behind OBJ%x after wait", + object->fscache.debug_id, + xobject->fscache.debug_id); + goto requeue; + } + + if (timeout <= 0) { + printk(KERN_ERR "\n"); + printk(KERN_ERR "CacheFiles: Error: Overlong" + " wait for old active object to go away\n"); + cachefiles_printk_object(object, xobject); + goto requeue; + } + } + + ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)); cache->cache.ops->put_object(&xobject->fscache); goto try_again; + +requeue: + clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); + cache->cache.ops->put_object(&xobject->fscache); + _leave(" = -ETIMEDOUT"); + return -ETIMEDOUT; } /* @@ -466,12 +511,15 @@ lookup_again: } /* note that we're now using this object */ - cachefiles_mark_object_active(cache, object); + ret = cachefiles_mark_object_active(cache, object); mutex_unlock(&dir->d_inode->i_mutex); dput(dir); dir = NULL; + if (ret == -ETIMEDOUT) + goto mark_active_timed_out; + _debug("=== OBTAINED_OBJECT ==="); if (object->new) { @@ -515,6 +563,10 @@ create_error: cachefiles_io_error(cache, "Create/mkdir failed"); goto error; +mark_active_timed_out: + _debug("mark active timed out"); + goto release_dentry; + check_error: _debug("check error %d", ret); write_lock(&cache->active_lock); @@ -522,7 +574,7 @@ check_error: clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE); write_unlock(&cache->active_lock); - +release_dentry: dput(object->dentry); object->dentry = NULL; goto error_out; @@ -543,9 +595,6 @@ error: error_out2: dput(dir); error_out: - if (ret == -ENOSPC) - ret = -ENOBUFS; - _leave(" = error %d", -ret); return ret; } |