diff options
| author | Jan Kara <jack@suse.cz> | 2017-02-02 15:56:51 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-02-02 16:20:50 +0100 |
| commit | d03f6cdc1fc422accb734c7c07a661a0018d8631 (patch) | |
| tree | fe3500795df51b8ad11a0f76dddfa27d60fecf13 /mm/backing-dev.c | |
| parent | block: Use pointer to backing_dev_info from request_queue (diff) | |
| download | linux-d03f6cdc1fc422accb734c7c07a661a0018d8631.tar.xz linux-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 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 34 |
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); |