| Message ID | 164325158956.29787.7016948342209980097.stgit@noble.brown |
|---|---|
| State | New |
| Headers | show |
| Series | Remove remaining parts of congestions tracking code. | expand |
On 01/27, NeilBrown wrote: > 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@suse.de> > --- > 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)); Since checkpoint uses down_write(cp_rwsem), I'm not sure the write path is safe and needs to wait for checkpoint. Can we just do io_schedule_timeout()? > 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; >
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;
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@suse.de> --- fs/f2fs/compress.c | 6 +++--- fs/f2fs/data.c | 9 ++++++--- 2 files changed, 9 insertions(+), 6 deletions(-)