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| author | Tejun Heo <tj@kernel.org> | 2015-05-28 14:50:49 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-06-02 08:39:08 -0600 |
| commit | 21c6321fbb3a3787af07f1bc031d713a707fb69c (patch) | |
| tree | de5489853b7f0d82adfd74da30d3945aba45e366 /fs/fs-writeback.c | |
| parent | 97c9341f727105c29478da19f1687b0e0a917256 (diff) | |
| download | linux-21c6321fbb3a3787af07f1bc031d713a707fb69c.tar.gz linux-21c6321fbb3a3787af07f1bc031d713a707fb69c.tar.bz2 linux-21c6321fbb3a3787af07f1bc031d713a707fb69c.zip | |
writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
Currently, majority of cgroup writeback support including all the
above functions are implemented in include/linux/backing-dev.h and
mm/backing-dev.c; however, the portion closely related to writeback
logic implemented in include/linux/writeback.h and mm/page-writeback.c
will expand to support foreign writeback detection and correction.
This patch moves wb[_try]_get() and wb_put() to
include/linux/backing-dev-defs.h so that they can be used from
writeback.h and inode_{attach|detach}_wb() to writeback.h and
page-writeback.c.
This is pure reorganization and doesn't introduce any functional
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index da355879ba7c..cf6ccfb01e03 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -27,6 +27,7 @@ #include <linux/backing-dev.h> #include <linux/tracepoint.h> #include <linux/device.h> +#include <linux/memcontrol.h> #include "internal.h" /* @@ -213,6 +214,36 @@ static void wb_wait_for_completion(struct backing_dev_info *bdi, #ifdef CONFIG_CGROUP_WRITEBACK +void __inode_attach_wb(struct inode *inode, struct page *page) +{ + struct backing_dev_info *bdi = inode_to_bdi(inode); + struct bdi_writeback *wb = NULL; + + if (inode_cgwb_enabled(inode)) { + struct cgroup_subsys_state *memcg_css; + + if (page) { + memcg_css = mem_cgroup_css_from_page(page); + wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC); + } else { + /* must pin memcg_css, see wb_get_create() */ + memcg_css = task_get_css(current, memory_cgrp_id); + wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC); + css_put(memcg_css); + } + } + + if (!wb) + wb = &bdi->wb; + + /* + * There may be multiple instances of this function racing to + * update the same inode. Use cmpxchg() to tell the winner. + */ + if (unlikely(cmpxchg(&inode->i_wb, NULL, wb))) + wb_put(wb); +} + /** * inode_congested - test whether an inode is congested * @inode: inode to test for congestion |