[PATCH 3/9] f2fs: change retry waiting for f2fs_write_single_data_page()
From: NeilBrown <hidden>
Date: 2022-01-27 02:47:53
Also in:
ceph-devel, linux-block, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, lkml
Subsystem:
f2fs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Jaegeuk Kim, Chao Yu, Alexander Viro, Christian Brauner, Linus Torvalds
f2fs_write_single_data_page() can return -EAGAIN if it cannot get the cp_rwsem lock - it holds a page lock and so cannot wait for it. Some code which calls f2fs_write_single_data_page() use congestion_wait() and then tries again. congestion_wait() doesn't do anything useful as congestion is no longer tracked. So this is just a simple sleep. A better approach is it wait until the cp_rwsem lock can be taken - then try again. There is certainly no point trying again *before* the lock can be taken. Signed-off-by: NeilBrown <redacted> --- fs/f2fs/compress.c | 6 +++--- fs/f2fs/data.c | 9 ++++++--- 2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index d0c3aeba5945..58ff7f4b296c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c@@ -1505,9 +1505,9 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc, if (IS_NOQUOTA(cc->inode)) return 0; ret = 0; - cond_resched(); - congestion_wait(BLK_RW_ASYNC, - DEFAULT_IO_TIMEOUT); + /* Wait until we can get the lock, then try again. */ + f2fs_lock_op(F2FS_I_SB(cc->inode)); + f2fs_unlock_op(F2FS_I_SB(cc->inode)); goto retry_write; } return ret;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8c417864c66a..1d2341163e2c 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c@@ -3047,9 +3047,12 @@ static int f2fs_write_cache_pages(struct address_space *mapping, } else if (ret == -EAGAIN) { ret = 0; if (wbc->sync_mode == WB_SYNC_ALL) { - cond_resched(); - congestion_wait(BLK_RW_ASYNC, - DEFAULT_IO_TIMEOUT); + /* Wait until we can get the + * lock, then try again. + */ + f2fs_lock_op(F2FS_I_SB(mapping->host)); + f2fs_unlock_op(F2FS_I_SB(mapping->host)); + goto retry_write; } goto next;