On Tue, Nov 14, 2017 at 04:56:47PM -0500, Josef Bacik wrote:
> From: Josef Bacik <jbacik@xxxxxx>
>
> 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.
>
One question below.
> Signed-off-by: Josef Bacik <jbacik@xxxxxx>
> Reviewed-by: Jan Kara <jack@xxxxxxx>
> ---
> drivers/mtd/devices/block2mtd.c | 12 ++++++++----
> fs/btrfs/disk-io.c | 3 ++-
> fs/btrfs/file.c | 3 ++-
> fs/btrfs/ioctl.c | 3 ++-
> fs/btrfs/relocation.c | 3 ++-
> fs/buffer.c | 3 ++-
> fs/iomap.c | 6 ++++--
> fs/ntfs/attrib.c | 11 ++++++++---
> fs/ntfs/file.c | 4 ++--
> include/linux/backing-dev.h | 29 +++++++++++++++++++++++------
> include/linux/writeback.h | 4 +++-
> mm/filemap.c | 4 +++-
> mm/memory.c | 5 ++++-
> mm/page-writeback.c | 15 +++++++--------
> 14 files changed, 72 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
> index 7c887f111a7d..7892d0b9fcb0 100644
> --- a/drivers/mtd/devices/block2mtd.c
> +++ b/drivers/mtd/devices/block2mtd.c
> @@ -52,7 +52,8 @@ static struct page *page_read(struct address_space *mapping, int index)
> /* erase a specified part of the device */
> static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
> {
> - struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
> + struct inode *inode = dev->blkdev->bd_inode;
> + struct address_space *mapping = inode->i_mapping;
> struct page *page;
> int index = to >> PAGE_SHIFT; // page index
> int pages = len >> PAGE_SHIFT;
> @@ -71,7 +72,8 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
> memset(page_address(page), 0xff, PAGE_SIZE);
> set_page_dirty(page);
> unlock_page(page);
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> break;
> }
>
> @@ -141,7 +143,8 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
> loff_t to, size_t len, size_t *retlen)
> {
> struct page *page;
> - struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
> + struct inode *inode = dev->blkdev->bd_inode;
> + struct address_space *mapping = inode->i_mapping;
> int index = to >> PAGE_SHIFT; // page index
> int offset = to & ~PAGE_MASK; // page offset
> int cpylen;
> @@ -162,7 +165,8 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
> memcpy(page_address(page) + offset, buf, cpylen);
> set_page_dirty(page);
> unlock_page(page);
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> }
> put_page(page);
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 689b9913ccb5..8b6df7688d52 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -4150,7 +4150,8 @@ static void __btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info,
> ret = percpu_counter_compare(&fs_info->dirty_metadata_bytes,
> BTRFS_DIRTY_METADATA_THRESH);
> if (ret > 0) {
> - balance_dirty_pages_ratelimited(fs_info->btree_inode->i_mapping);
> + balance_dirty_pages_ratelimited(fs_info->sb->s_bdi,
> + fs_info->sb);
> }
> }
>
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index ab1c38f2dd8c..4bc6cd6509be 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -1779,7 +1779,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
>
> cond_resched();
>
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
> btrfs_btree_balance_dirty(fs_info);
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 6a07d4e12fd2..ec92fb5e2b51 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1368,7 +1368,8 @@ 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 4cf2eb67eba6..9f31c5e6c0e5 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -3278,7 +3278,8 @@ static int relocate_file_extent_cluster(struct inode *inode,
>
> index++;
> btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> btrfs_throttle(fs_info);
> }
> WARN_ON(nr != cluster->nr);
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 170df856bdb9..36be326a316c 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2421,7 +2421,8 @@ 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 269b24a01f32..0eb1ec680f87 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -223,7 +223,8 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> 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;
> @@ -305,7 +306,8 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> written += status;
> length -= status;
>
> - balance_dirty_pages_ratelimited(inode->i_mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> } while (length);
>
> return written;
> diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
> index 44a39a099b54..d85368dd82e7 100644
> --- a/fs/ntfs/attrib.c
> +++ b/fs/ntfs/attrib.c
> @@ -25,6 +25,7 @@
> #include <linux/slab.h>
> #include <linux/swap.h>
> #include <linux/writeback.h>
> +#include <linux/backing-dev.h>
>
> #include "attrib.h"
> #include "debug.h"
> @@ -2493,6 +2494,7 @@ s64 ntfs_attr_extend_allocation(ntfs_inode *ni, s64 new_alloc_size,
> int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
> {
> ntfs_volume *vol = ni->vol;
> + struct inode *inode = VFS_I(ni);
> struct address_space *mapping;
> struct page *page;
> u8 *kaddr;
> @@ -2545,7 +2547,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
> kunmap_atomic(kaddr);
> set_page_dirty(page);
> put_page(page);
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> cond_resched();
> if (idx == end)
> goto done;
> @@ -2586,7 +2589,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
> /* Finally unlock and release the page. */
> unlock_page(page);
> put_page(page);
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> cond_resched();
> }
> /* If there is a last partial page, need to do it the slow way. */
> @@ -2603,7 +2607,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
> kunmap_atomic(kaddr);
> set_page_dirty(page);
> put_page(page);
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(inode),
> + inode->i_sb);
> cond_resched();
> }
> done:
> diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
> index 331910fa8442..77b04be4a157 100644
> --- a/fs/ntfs/file.c
> +++ b/fs/ntfs/file.c
> @@ -276,7 +276,7 @@ static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size)
> * number of pages we read and make dirty in the case of sparse
> * files.
> */
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(vi), vi->i_sb);
> cond_resched();
> } while (++index < end_index);
> read_lock_irqsave(&ni->size_lock, flags);
> @@ -1913,7 +1913,7 @@ static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
> iov_iter_advance(i, copied);
> pos += copied;
> written += copied;
> - balance_dirty_pages_ratelimited(mapping);
> + balance_dirty_pages_ratelimited(inode_to_bdi(vi), vi->i_sb);
> if (fatal_signal_pending(current)) {
> status = -EINTR;
> break;
> diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
> index 854e1bdd0b2a..14e266d12620 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -228,8 +228,9 @@ 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
> @@ -238,15 +239,25 @@ 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);
> }
>
> /**
> @@ -389,6 +400,12 @@ static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked)
>
> #else /* CONFIG_CGROUP_WRITEBACK */
>
> +static inline bool bdi_cgwb_enabled(struct backing_dev_info *bdi,
> + struct super_block *sb)
> +{
> + return false;
> +}
> +
> static inline bool inode_cgwb_enabled(struct inode *inode)
> {
> return false;
> diff --git a/include/linux/writeback.h b/include/linux/writeback.h
> index d5815794416c..fa799a4a7755 100644
> --- a/include/linux/writeback.h
> +++ b/include/linux/writeback.h
> @@ -376,7 +376,9 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
> 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 balance_dirty_pages_ratelimited(struct address_space *mapping);
> +void page_writeback_init(void);
I'm not getting why page_writeback_init() is exported here.
Others look good.
Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
Thanks,
-liubo
> +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 870971e20967..5ea4878e9c78 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2971,6 +2971,7 @@ 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;
> @@ -3044,7 +3045,8 @@ ssize_t generic_perform_write(struct file *file,
> 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 ec4e15494901..86f31b3d54c6 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -70,6 +70,7 @@
> #include <linux/userfaultfd_k.h>
> #include <linux/dax.h>
> #include <linux/oom.h>
> +#include <linux/backing-dev.h>
>
> #include <asm/io.h>
> #include <asm/mmu_context.h>
> @@ -2391,11 +2392,13 @@ static void fault_dirty_shared_page(struct vm_area_struct *vma,
> unlock_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)
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 0b9c5cbe8eba..1a47d4296750 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) };
> @@ -1850,7 +1849,8 @@ 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
> @@ -1861,10 +1861,9 @@ 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;
> @@ -1872,7 +1871,7 @@ 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;
> @@ -1910,7 +1909,7 @@ 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);
> }
> --
> 2.7.5
>
