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| author | Haifeng Xu <haifeng.xu@shopee.com> | 2024-07-26 11:05:25 +0800 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-08-19 13:45:02 +0200 |
| commit | c393eaa85349941badf3ce5f087400dbaf3bbe02 (patch) | |
| tree | e191d567644cfb12afcf720d93a2338475684e89 | |
| parent | e02bdb7208e7b5432cbe68392ae062810a7649fb (diff) | |
| download | linux-c393eaa85349941badf3ce5f087400dbaf3bbe02.tar.gz linux-c393eaa85349941badf3ce5f087400dbaf3bbe02.tar.bz2 linux-c393eaa85349941badf3ce5f087400dbaf3bbe02.zip | |
fs: don't flush in-flight wb switches for superblocks without cgroup writeback
When deactivating any type of superblock, it had to wait for the in-flight
wb switches to be completed. wb switches are executed in inode_switch_wbs_work_fn()
which needs to acquire the wb_switch_rwsem and races against sync_inodes_sb().
If there are too much dirty data in the superblock, the waiting time may increase
significantly.
For superblocks without cgroup writeback such as tmpfs, they have nothing to
do with the wb swithes, so the flushing can be avoided.
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Link: https://lore.kernel.org/r/20240726030525.180330-1-haifeng.xu@shopee.com
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/fs-writeback.c | 7 | ||||
| -rw-r--r-- | fs/super.c | 2 | ||||
| -rw-r--r-- | include/linux/writeback.h | 4 |
3 files changed, 9 insertions, 4 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index b865a3fa52f3..4451ecff37c4 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1132,6 +1132,7 @@ out_bdi_put: /** * cgroup_writeback_umount - flush inode wb switches for umount + * @sb: target super_block * * This function is called when a super_block is about to be destroyed and * flushes in-flight inode wb switches. An inode wb switch goes through @@ -1140,8 +1141,12 @@ out_bdi_put: * rare occurrences and synchronize_rcu() can take a while, perform * flushing iff wb switches are in flight. */ -void cgroup_writeback_umount(void) +void cgroup_writeback_umount(struct super_block *sb) { + + if (!(sb->s_bdi->capabilities & BDI_CAP_WRITEBACK)) + return; + /* * SB_ACTIVE should be reliably cleared before checking * isw_nr_in_flight, see generic_shutdown_super(). diff --git a/fs/super.c b/fs/super.c index 38d72a3cf6fc..28f42502bdf9 100644 --- a/fs/super.c +++ b/fs/super.c @@ -621,7 +621,7 @@ void generic_shutdown_super(struct super_block *sb) sync_filesystem(sb); sb->s_flags &= ~SB_ACTIVE; - cgroup_writeback_umount(); + cgroup_writeback_umount(sb); /* Evict all inodes with zero refcount. */ evict_inodes(sb); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 1a54676d843a..56b85841ae4c 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -217,7 +217,7 @@ void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page, size_t bytes); int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, enum wb_reason reason, struct wb_completion *done); -void cgroup_writeback_umount(void); +void cgroup_writeback_umount(struct super_block *sb); bool cleanup_offline_cgwb(struct bdi_writeback *wb); /** @@ -324,7 +324,7 @@ static inline void wbc_account_cgroup_owner(struct writeback_control *wbc, { } -static inline void cgroup_writeback_umount(void) +static inline void cgroup_writeback_umount(struct super_block *sb) { } |