On Tue 09-08-16 15:08:26, Josef Bacik wrote:
> The only reason we pass in the mapping is to get the inode in order to see if
> writeback cgroups is enabled, and even then it only checks the bdi and a super
> block flag. balance_dirty_pages() doesn't even use the mapping. Since
> balance_dirty_pages*() works on a bdi level, just pass in the bdi and super
> block directly so we can avoid using mapping. This will allow us to still use
> balance_dirty_pages for dirty metadata pages that are not backed by an
> address_mapping.
>
> Signed-off-by: Josef Bacik <jbacik@xxxxxx>
The patch looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/btrfs/disk-io.c | 4 ++--
> fs/btrfs/file.c | 3 ++-
> fs/btrfs/ioctl.c | 3 ++-
> fs/btrfs/relocation.c | 3 ++-
> fs/buffer.c | 3 ++-
> fs/iomap.c | 3 ++-
> include/linux/backing-dev.h | 23 +++++++++++++++++------
> include/linux/writeback.h | 3 ++-
> mm/filemap.c | 4 +++-
> mm/memory.c | 9 +++++++--
> mm/page-writeback.c | 15 +++++++--------
> 11 files changed, 48 insertions(+), 25 deletions(-)
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 17346f7..c1d951a 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -4024,8 +4024,8 @@ static void __btrfs_btree_balance_dirty(struct btrfs_root *root,
> ret = percpu_counter_compare(&root->fs_info->dirty_metadata_bytes,
> BTRFS_DIRTY_METADATA_THRESH);
> if (ret > 0) {
> - balance_dirty_pages_ratelimited(
> - root->fs_info->btree_inode->i_mapping);
> + balance_dirty_pages_ratelimited(&root->fs_info->bdi,
> + root->fs_info->sb);
> }
> }
>
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index 9404121..f060b08 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -1686,7 +1686,8 @@ again:
>
> cond_resched();
>
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> if (dirty_pages < (root->nodesize >> PAGE_SHIFT) + 1)
> btrfs_btree_balance_dirty(root);
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 14ed1e9..a222bad 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1410,7 +1410,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
> }
>
> defrag_count += ret;
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> inode_unlock(inode);
>
> if (newer_than) {
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index 4598e29..7fc6ea7 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -3202,7 +3202,8 @@ static int relocate_file_extent_cluster(struct inode *inode,
> put_page(page);
>
> index++;
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> btrfs_throttle(BTRFS_I(inode)->root);
> }
> WARN_ON(nr != cluster->nr);
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 9c8eb9b..9bbe30d 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2386,7 +2386,8 @@ static int cont_expand_zero(struct file *file, struct address_space *mapping,
> BUG_ON(err != len);
> err = 0;
>
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
>
> if (unlikely(fatal_signal_pending(current))) {
> err = -EINTR;
> diff --git a/fs/iomap.c b/fs/iomap.c
> index 48141b8..937e266 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -226,7 +226,8 @@ again:
> written += copied;
> length -= copied;
>
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> } while (iov_iter_count(i) && length);
>
> return written ? written : status;
> diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
> index 491a917..3b76eeb 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -252,8 +252,9 @@ void wb_blkcg_offline(struct blkcg *blkcg);
> int inode_congested(struct inode *inode, int cong_bits);
>
> /**
> - * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode
> - * @inode: inode of interest
> + * bdi_cgwb_enabled - test wether cgroup writeback is enabled on a filesystem
> + * @bdi: the bdi we care about
> + * @sb: the super for the bdi
> *
> * cgroup writeback requires support from both the bdi and filesystem.
> * Also, both memcg and iocg have to be on the default hierarchy. Test
> @@ -262,15 +263,25 @@ int inode_congested(struct inode *inode, int cong_bits);
> * Note that the test result may change dynamically on the same inode
> * depending on how memcg and iocg are configured.
> */
> -static inline bool inode_cgwb_enabled(struct inode *inode)
> +static inline bool bdi_cgwb_enabled(struct backing_dev_info *bdi,
> + struct super_block *sb)
> {
> - struct backing_dev_info *bdi = inode_to_bdi(inode);
> -
> return cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
> cgroup_subsys_on_dfl(io_cgrp_subsys) &&
> bdi_cap_account_dirty(bdi) &&
> (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
> - (inode->i_sb->s_iflags & SB_I_CGROUPWB);
> + (sb->s_iflags & SB_I_CGROUPWB);
> +}
> +
> +/**
> + * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode
> + * @inode: inode of interest
> + *
> + * Does the inode have cgroup writeback support.
> + */
> +static inline bool inode_cgwb_enabled(struct inode *inode)
> +{
> + return bdi_cgwb_enabled(inode_to_bdi(inode), inode->i_sb);
> }
>
> /**
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index fc1e16c..256ffc3 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -364,7 +364,8 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh);
>
> void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time);
> void page_writeback_init(void);
> -void balance_dirty_pages_ratelimited(struct address_space *mapping);
> +void balance_dirty_pages_ratelimited(struct backing_dev_info *bdi,
> + struct super_block *sb);
> bool wb_over_bg_thresh(struct bdi_writeback *wb);
>
> typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 3083ded..abb0e98 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2667,6 +2667,7 @@ ssize_t generic_perform_write(struct file *file,
> struct iov_iter *i, loff_t pos)
> {
> struct address_space *mapping = file->f_mapping;
> + struct inode *inode = mapping->host;
> const struct address_space_operations *a_ops = mapping->a_ops;
> long status = 0;
> ssize_t written = 0;
> @@ -2746,7 +2747,8 @@ again:
> pos += copied;
> written += copied;
>
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> } while (iov_iter_count(i));
>
> return written ? written : status;
> diff --git a/mm/memory.c b/mm/memory.c
> index 83be99d..d43e73b 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -64,6 +64,7 @@
> #include <linux/debugfs.h>
> #include <linux/userfaultfd_k.h>
> #include <linux/dax.h>
> +#include <linux/backing-dev.h>
>
> #include <asm/io.h>
> #include <asm/mmu_context.h>
> @@ -2105,11 +2106,13 @@ static inline int wp_page_reuse(struct fault_env *fe, pte_t orig_pte,
> put_page(page);
>
> if ((dirtied || page_mkwrite) && mapping) {
> + struct inode *inode = mapping->host;
> /*
> * Some device drivers do not set page.mapping
> * but still dirty their pages
> */
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> }
>
> if (!page_mkwrite)
> @@ -3291,11 +3294,13 @@ static int do_shared_fault(struct fault_env *fe, pgoff_t pgoff)
> mapping = page_rmapping(fault_page);
> unlock_page(fault_page);
> if ((dirtied || vma->vm_ops->page_mkwrite) && mapping) {
> + struct inode *inode = mapping->host;
> /*
> * Some device drivers do not set page.mapping but still
> * dirty their pages
> */
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> }
>
> if (!vma->vm_ops->page_mkwrite)
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index f4cd7d8..121a6e3 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -1559,8 +1559,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
> * If we're over `background_thresh' then the writeback threads are woken to
> * perform some writeout.
> */
> -static void balance_dirty_pages(struct address_space *mapping,
> - struct bdi_writeback *wb,
> +static void balance_dirty_pages(struct bdi_writeback *wb,
> unsigned long pages_dirtied)
> {
> struct dirty_throttle_control gdtc_stor = { GDTC_INIT(wb) };
> @@ -1849,7 +1848,8 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
>
> /**
> * balance_dirty_pages_ratelimited - balance dirty memory state
> - * @mapping: address_space which was dirtied
> + * @bdi: the bdi that was dirtied
> + * @sb: the super block that was dirtied
> *
> * Processes which are dirtying memory should call in here once for each page
> * which was newly dirtied. The function will periodically check the system's
> @@ -1860,10 +1860,9 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0;
> * limit we decrease the ratelimiting by a lot, to prevent individual processes
> * from overshooting the limit by (ratelimit_pages) each.
> */
> -void balance_dirty_pages_ratelimited(struct address_space *mapping)
> +void balance_dirty_pages_ratelimited(struct backing_dev_info *bdi,
> + struct super_block *sb)
> {
> - struct inode *inode = mapping->host;
> - struct backing_dev_info *bdi = inode_to_bdi(inode);
> struct bdi_writeback *wb = NULL;
> int ratelimit;
> int *p;
> @@ -1871,7 +1870,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
> if (!bdi_cap_account_dirty(bdi))
> return;
>
> - if (inode_cgwb_enabled(inode))
> + if (bdi_cgwb_enabled(bdi, sb))
> wb = wb_get_create_current(bdi, GFP_KERNEL);
> if (!wb)
> wb = &bdi->wb;
> @@ -1909,7 +1908,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
> preempt_enable();
>
> if (unlikely(current->nr_dirtied >= ratelimit))
> - balance_dirty_pages(mapping, wb, current->nr_dirtied);
> + balance_dirty_pages(wb, current->nr_dirtied);
>
> wb_put(wb);
> }
> --
> 1.8.3.1
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
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