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| author | Namjae Jeon <linkinjeon@kernel.org> | 2022-07-28 23:35:18 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2022-07-31 23:14:32 -0500 |
| commit | a14c573870a664386adc10526a6c2648ea56dae1 (patch) | |
| tree | b7d174950764bbaa0a81d0c927ef27d73b6db7cd /fs/ksmbd/oplock.c | |
| parent | 17ea92a9f6d0b9a97aaec5ab748e4591d70a562c (diff) | |
| download | lwn-a14c573870a664386adc10526a6c2648ea56dae1.tar.gz lwn-a14c573870a664386adc10526a6c2648ea56dae1.zip | |
ksmbd: use wait_event instead of schedule_timeout()
ksmbd threads eating masses of cputime when connection is disconnected.
If connection is disconnected, ksmbd thread waits for pending requests
to be processed using schedule_timeout. schedule_timeout() incorrectly
is used, and it is more efficient to use wait_event/wake_up than to check
r_count every time with timeout.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/ksmbd/oplock.c')
| -rw-r--r-- | fs/ksmbd/oplock.c | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 8b5560574d4c..3ef33ed4cdba 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -615,18 +615,13 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) struct ksmbd_file *fp; fp = ksmbd_lookup_durable_fd(br_info->fid); - if (!fp) { - atomic_dec(&conn->r_count); - ksmbd_free_work_struct(work); - return; - } + if (!fp) + goto out; if (allocate_oplock_break_buf(work)) { pr_err("smb2_allocate_rsp_buf failed! "); - atomic_dec(&conn->r_count); ksmbd_fd_put(work, fp); - ksmbd_free_work_struct(work); - return; + goto out; } rsp_hdr = smb2_get_msg(work->response_buf); @@ -667,8 +662,16 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) ksmbd_fd_put(work, fp); ksmbd_conn_write(work); + +out: ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); } /** @@ -731,9 +734,7 @@ static void __smb2_lease_break_noti(struct work_struct *wk) if (allocate_oplock_break_buf(work)) { ksmbd_debug(OPLOCK, "smb2_allocate_rsp_buf failed! "); - ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); - return; + goto out; } rsp_hdr = smb2_get_msg(work->response_buf); @@ -771,8 +772,16 @@ static void __smb2_lease_break_noti(struct work_struct *wk) inc_rfc1001_len(work->response_buf, 44); ksmbd_conn_write(work); + +out: ksmbd_free_work_struct(work); - atomic_dec(&conn->r_count); + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); } /** |