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authorJens Axboe <jens.axboe@oracle.com>2010-04-22 11:37:01 +0200
committerJens Axboe <jens.axboe@oracle.com>2010-04-22 11:39:36 +0200
commitc3c532061e46156e8aab1268f38d66cfb63aeb2d (patch)
tree8c5b027873b823b04f5564d442477e80e82e8edb /mm
parenta534dbe96e9929c7245924d8252d89048c23d569 (diff)
bdi: add helper function for doing init and register of a bdi for a file system
Pretty trivial helper, just sets up the bdi and registers it. An atomic sequence count is used to ensure that the registered sysfs names are unique. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'mm')
-rw-r--r--mm/backing-dev.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f13e067e1467..dbda4707f593 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -11,6 +11,8 @@
#include <linux/writeback.h>
#include <linux/device.h>
+static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
+
void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
{
}
@@ -715,6 +717,33 @@ void bdi_destroy(struct backing_dev_info *bdi)
}
EXPORT_SYMBOL(bdi_destroy);
+/*
+ * For use from filesystems to quickly init and register a bdi associated
+ * with dirty writeback
+ */
+int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
+ unsigned int cap)
+{
+ char tmp[32];
+ int err;
+
+ bdi->name = name;
+ bdi->capabilities = cap;
+ err = bdi_init(bdi);
+ if (err)
+ return err;
+
+ sprintf(tmp, "%.28s%s", name, "-%d");
+ err = bdi_register(bdi, NULL, tmp, atomic_long_inc_return(&bdi_seq));
+ if (err) {
+ bdi_destroy(bdi);
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(bdi_setup_and_register);
+
static wait_queue_head_t congestion_wqh[2] = {
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])