From ed7b6b4f6e915cb0bc52d0000bcc63168867b6ac Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:35 +0200 Subject: bdi: remove BDI_CAP_CGROUP_WRITEBACK Just checking SB_I_CGROUPWB for cgroup writeback support is enough. Either the file system allocates its own bdi (e.g. btrfs), in which case it is known to support cgroup writeback, or the bdi comes from the block layer, which always supports cgroup writeback. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'include/linux/backing-dev.h') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 0b06b2d26c9a..52583b6f2ea0 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -123,7 +123,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * 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. * BDI_CAP_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be * inefficient. */ @@ -233,9 +232,9 @@ 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 * - * cgroup writeback requires support from both the bdi and filesystem. - * Also, both memcg and iocg have to be on the default hierarchy. Test - * whether all conditions are met. + * Cgroup writeback requires support from the filesystem. Also, both memcg and + * iocg have to be on the default hierarchy. Test whether all conditions are + * met. * * Note that the test result may change dynamically on the same inode * depending on how memcg and iocg are configured. @@ -247,7 +246,6 @@ static inline bool inode_cgwb_enabled(struct inode *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); } -- cgit v1.2.3 From a8b456d01cd6b37191f14248f3e2bdbe5ce3a89e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:36 +0200 Subject: bdi: remove BDI_CAP_SYNCHRONOUS_IO BDI_CAP_SYNCHRONOUS_IO is only checked in the swap code, and used to decided if ->rw_page can be used on a block device. Just check up for the method instead. The only complication is that zram needs a second set of block_device_operations as it can switch between modes that actually support ->rw_page and those who don't. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'include/linux/backing-dev.h') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 52583b6f2ea0..860ea33571bc 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -122,9 +122,6 @@ 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_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be - * inefficient. */ #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 @@ -132,7 +129,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_STABLE_WRITES 0x00000008 #define BDI_CAP_STRICTLIMIT 0x00000010 #define BDI_CAP_CGROUP_WRITEBACK 0x00000020 -#define BDI_CAP_SYNCHRONOUS_IO 0x00000040 #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) @@ -174,11 +170,6 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi) -{ - return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO; -} - static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) { return bdi->capabilities & BDI_CAP_STABLE_WRITES; -- cgit v1.2.3 From 1cb039f3dc1619eb795c54aad0a98fdb379b4237 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:38 +0200 Subject: bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag The BDI_CAP_STABLE_WRITES is one of the few bits of information in the backing_dev_info shared between the block drivers and the writeback code. To help untangling the dependency replace it with a queue flag and a superblock flag derived from it. This also helps with the case of e.g. a file system requiring stable writes due to its own checksumming, but not forcing it on other users of the block device like the swap code. One downside is that we an't support the stable_pages_required bdi attribute in sysfs anymore. It is replaced with a queue attribute which also is writable for easier testing. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/backing-dev.h') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 860ea33571bc..5da4ea3dd0cc 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -126,7 +126,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #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 @@ -170,11 +169,6 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi) -{ - return bdi->capabilities & BDI_CAP_STABLE_WRITES; -} - static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) { return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); -- cgit v1.2.3 From 823423ef55f4d9c470b1edc9c5b5c93d06abfaae Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:39 +0200 Subject: bdi: invert BDI_CAP_NO_ACCT_WB Replace BDI_CAP_NO_ACCT_WB with a positive BDI_CAP_WRITEBACK_ACCT to make the checks more obvious. Also remove the pointless bdi_cap_account_writeback wrapper that just obsfucates the check. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'include/linux/backing-dev.h') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 5da4ea3dd0cc..b217344a2c63 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -120,17 +120,17 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); * * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting * BDI_CAP_NO_WRITEBACK: Don't write pages back - * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages + * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. */ #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 #define BDI_CAP_NO_WRITEBACK 0x00000002 -#define BDI_CAP_NO_ACCT_WB 0x00000004 +#define BDI_CAP_WRITEBACK_ACCT 0x00000004 #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) + (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY) extern struct backing_dev_info noop_backing_dev_info; @@ -179,13 +179,6 @@ static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); } -static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) -{ - /* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */ - return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB | - BDI_CAP_NO_WRITEBACK)); -} - static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) { return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); -- cgit v1.2.3 From f56753ac2a90810726334df04d735e9f8f5a32d9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:40 +0200 Subject: bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag Replace the two negative flags that are always used together with a single positive flag that indicates the writeback capability instead of two related non-capabilities. Also remove the pointless wrappers to just check the flag. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 48 ++++++++++----------------------------------- 1 file changed, 10 insertions(+), 38 deletions(-) (limited to 'include/linux/backing-dev.h') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index b217344a2c63..44df4fcef65c 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -110,27 +110,14 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); /* * Flags in backing_dev_info::capability * - * The first three flags control whether dirty pages will contribute to the - * VM's accounting and whether writepages() should be called for dirty pages - * (something that would not, for example, be appropriate for ramfs) - * - * WARNING: these flags are closely related and should not normally be - * used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these - * three flags into a single convenience macro. - * - * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting - * BDI_CAP_NO_WRITEBACK: Don't write pages back - * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages - * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. + * BDI_CAP_WRITEBACK: Supports dirty page writeback, and dirty pages + * should contribute to accounting + * BDI_CAP_WRITEBACK_ACCT: Automatically account writeback pages + * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold */ -#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 -#define BDI_CAP_NO_WRITEBACK 0x00000002 -#define BDI_CAP_WRITEBACK_ACCT 0x00000004 -#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) +#define BDI_CAP_WRITEBACK (1 << 0) +#define BDI_CAP_WRITEBACK_ACCT (1 << 1) +#define BDI_CAP_STRICTLIMIT (1 << 2) extern struct backing_dev_info noop_backing_dev_info; @@ -169,24 +156,9 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) long congestion_wait(int sync, long timeout); long wait_iff_congested(int sync, long timeout); -static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) -{ - return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); -} - -static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) -{ - return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); -} - -static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) -{ - return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host)); -} - -static inline bool mapping_cap_account_dirty(struct address_space *mapping) +static inline bool mapping_can_writeback(struct address_space *mapping) { - return bdi_cap_account_dirty(inode_to_bdi(mapping->host)); + return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK; } static inline int bdi_sched_wait(void *word) @@ -223,7 +195,7 @@ static inline bool inode_cgwb_enabled(struct inode *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_WRITEBACK) && (inode->i_sb->s_iflags & SB_I_CGROUPWB); } -- cgit v1.2.3