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authorJan Kara <jack@suse.cz>2017-02-02 15:56:51 +0100
committerJens Axboe <axboe@fb.com>2017-02-02 08:20:50 -0700
commitd03f6cdc1fc422accb734c7c07a661a0018d8631 (patch)
treefe3500795df51b8ad11a0f76dddfa27d60fecf13 /mm/backing-dev.c
parentblock: Use pointer to backing_dev_info from request_queue (diff)
downloadlinux-dev-d03f6cdc1fc422accb734c7c07a661a0018d8631.tar.xz
linux-dev-d03f6cdc1fc422accb734c7c07a661a0018d8631.zip
block: Dynamically allocate and refcount backing_dev_info
Instead of storing backing_dev_info inside struct request_queue, allocate it dynamically, reference count it, and free it when the last reference is dropped. Currently only request_queue holds the reference but in the following patch we add other users referencing backing_dev_info. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to '')
-rw-r--r--mm/backing-dev.c34
1 files changed, 33 insertions, 1 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 3bfed5ab2475..28ce6cf7b2ff 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -237,6 +237,7 @@ static __init int bdi_class_init(void)
bdi_class->dev_groups = bdi_dev_groups;
bdi_debug_init();
+
return 0;
}
postcore_initcall(bdi_class_init);
@@ -776,6 +777,7 @@ int bdi_init(struct backing_dev_info *bdi)
bdi->dev = NULL;
+ kref_init(&bdi->refcnt);
bdi->min_ratio = 0;
bdi->max_ratio = 100;
bdi->max_prop_frac = FPROP_FRAC_BASE;
@@ -791,6 +793,22 @@ int bdi_init(struct backing_dev_info *bdi)
}
EXPORT_SYMBOL(bdi_init);
+struct backing_dev_info *bdi_alloc_node(gfp_t gfp_mask, int node_id)
+{
+ struct backing_dev_info *bdi;
+
+ bdi = kmalloc_node(sizeof(struct backing_dev_info),
+ gfp_mask | __GFP_ZERO, node_id);
+ if (!bdi)
+ return NULL;
+
+ if (bdi_init(bdi)) {
+ kfree(bdi);
+ return NULL;
+ }
+ return bdi;
+}
+
int bdi_register(struct backing_dev_info *bdi, struct device *parent,
const char *fmt, ...)
{
@@ -871,12 +889,26 @@ void bdi_unregister(struct backing_dev_info *bdi)
}
}
-void bdi_exit(struct backing_dev_info *bdi)
+static void bdi_exit(struct backing_dev_info *bdi)
{
WARN_ON_ONCE(bdi->dev);
wb_exit(&bdi->wb);
}
+static void release_bdi(struct kref *ref)
+{
+ struct backing_dev_info *bdi =
+ container_of(ref, struct backing_dev_info, refcnt);
+
+ bdi_exit(bdi);
+ kfree(bdi);
+}
+
+void bdi_put(struct backing_dev_info *bdi)
+{
+ kref_put(&bdi->refcnt, release_bdi);
+}
+
void bdi_destroy(struct backing_dev_info *bdi)
{
bdi_unregister(bdi);