Commit 89e9b9e0 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACK



cgroup writeback requires support from both bdi and filesystem sides.
Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate
support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by
default.  Also, define CONFIG_CGROUP_WRITEBACK which is enabled if
both MEMCG and BLK_CGROUP are enabled.

inode_cgwb_enabled() which determines whether a given inode's both bdi
and fs support cgroup writeback is added.
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 4aa9c692
......@@ -621,7 +621,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.capabilities = 0;
q->backing_dev_info.capabilities = BDI_CAP_CGROUP_WRITEBACK;
q->backing_dev_info.name = "block";
q->node = node_id;
......
......@@ -134,12 +134,15 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
* BDI_CAP_NO_WRITEBACK: Don't write pages back
* BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages
* BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold.
*
* BDI_CAP_CGROUP_WRITEBACK: Supports cgroup-aware writeback.
*/
#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
#define BDI_CAP_NO_WRITEBACK 0x00000002
#define BDI_CAP_NO_ACCT_WB 0x00000004
#define BDI_CAP_STABLE_WRITES 0x00000008
#define BDI_CAP_STRICTLIMIT 0x00000010
#define BDI_CAP_CGROUP_WRITEBACK 0x00000020
#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
(BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
......@@ -229,4 +232,31 @@ static inline int bdi_sched_wait(void *word)
return 0;
}
#endif /* _LINUX_BACKING_DEV_H */
#ifdef CONFIG_CGROUP_WRITEBACK
/**
* inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode
* @inode: inode of interest
*
* cgroup writeback requires support from both the bdi and filesystem.
* Test whether @inode has both.
*/
static inline bool inode_cgwb_enabled(struct inode *inode)
{
struct backing_dev_info *bdi = inode_to_bdi(inode);
return bdi_cap_account_dirty(bdi) &&
(bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
(inode->i_sb->s_type->fs_flags & FS_CGROUP_WRITEBACK);
}
#else /* CONFIG_CGROUP_WRITEBACK */
static inline bool inode_cgwb_enabled(struct inode *inode)
{
return false;
}
#endif /* CONFIG_CGROUP_WRITEBACK */
#endif /* _LINUX_BACKING_DEV_H */
......@@ -1897,6 +1897,7 @@ struct file_system_type {
#define FS_HAS_SUBTYPE 4
#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */
#define FS_USERNS_DEV_MOUNT 16 /* A userns mount does not imply MNT_NODEV */
#define FS_CGROUP_WRITEBACK 32 /* Supports cgroup-aware writeback */
#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */
struct dentry *(*mount) (struct file_system_type *, int,
const char *, void *);
......
......@@ -1141,6 +1141,11 @@ config DEBUG_BLK_CGROUP
Enable some debugging help. Currently it exports additional stat
files in a cgroup which can be useful for debugging.
config CGROUP_WRITEBACK
bool
depends on MEMCG && BLK_CGROUP
default y
endif # CGROUPS
config CHECKPOINT_RESTORE
......
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