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 <neilb@xxxxxxx>
---
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;
