Re: [PATCH] cifs: fix msleep() is imprecise

No。I just see Documentation/timers/timers-howto.rst and don't
recommend using msleep() for (1ms - 20ms). It recommends using
usleep_range(). And fsleep() is flexible sleeping.


On Wed, Jan 6, 2021 at 12:27 PM Steve French [off-list ref] wrote:

This patch seems reasonable at first glance, but I was a little
concerned that we don't see many users yet of fsleep.  Has there been
pushback on converting "yield" situations from using msleep to fsleep?

On Thu, Dec 10, 2020 at 3:09 AM Yejune Deng [off-list ref] wrote:

quoted

See Documentation/timers/timers-howto.rst, msleep() is not
for (1ms - 20ms), There is a more advanced API is used.

Signed-off-by: Yejune Deng <redacted>
---
 fs/cifs/cifsfs.c    |  4 ++--
 fs/cifs/connect.c   | 14 +++++++-------
 fs/cifs/file.c      |  6 +++---
 fs/cifs/smbdirect.c |  2 +-
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 472cb77..d35ce52 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c

@@ -664,10 +664,10 @@ static void cifs_umount_begin(struct super_block *sb)
                cifs_dbg(FYI, "wake up tasks now - umount begin not complete\n");
                wake_up_all(&tcon->ses->server->request_q);
                wake_up_all(&tcon->ses->server->response_q);
-               msleep(1); /* yield */
+               fsleep(1000); /* yield */
                /* we have to kick the requests once more */
                wake_up_all(&tcon->ses->server->response_q);
-               msleep(1);
+               fsleep(1000);
        }

        return;

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 44f9cce..62a9c64 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c

@@ -538,7 +538,7 @@ static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
                if (rc) {
                        cifs_dbg(FYI, "reconnect error %d\n", rc);
                        mutex_unlock(&server->srv_mutex);
-                       msleep(3000);
+                       ssleep(3);
                } else {
                        atomic_inc(&tcpSesReconnectCount);
                        set_credits(server, 1);

@@ -621,7 +621,7 @@ static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
                server->bigbuf = (char *)cifs_buf_get();
                if (!server->bigbuf) {
                        cifs_server_dbg(VFS, "No memory for large SMB response\n");
-                       msleep(3000);
+                       ssleep(3);
                        /* retry will check if exiting */
                        return false;
                }

@@ -634,7 +634,7 @@ static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
                server->smallbuf = (char *)cifs_small_buf_get();
                if (!server->smallbuf) {
                        cifs_server_dbg(VFS, "No memory for SMB response\n");
-                       msleep(1000);
+                       ssleep(1);
                        /* retry will check if exiting */
                        return false;
                }

@@ -729,7 +729,7 @@ static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
                         * to clear and app threads to set tcpStatus
                         * CifsNeedReconnect if server hung.
                         */
-                       usleep_range(1000, 2000);
+                       fsleep(1000);
                        length = 0;
                        continue;
                }

@@ -790,7 +790,7 @@ static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
                 */
                cifs_dbg(FYI, "RFC 1002 negative session response\n");
                /* give server a second to clean up */
-               msleep(1000);
+               ssleep(1);
                /*
                 * Always try 445 first on reconnect since we get NACK
                 * on some if we ever connected to port 139 (the NACK

@@ -944,7 +944,7 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
                 * response and going ahead and killing cifsd.
                 */
                cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
-               msleep(46000);
+               ssleep(46);
                /*
                 * If threads still have not exited they are probably never
                 * coming home not much else we can do but free the memory.

@@ -3655,7 +3655,7 @@ static void rfc1002mangle(char *target, char *source, unsigned int length)
                 * significant slowing down on mount
                 * for everyone else
                 */
-               usleep_range(1000, 2000);
+               fsleep(1000);
        }
        /*
         * else the negprot may still work without this

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index be46fab..75538a8 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c

@@ -283,7 +283,7 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
 cifs_down_write(struct rw_semaphore *sem)
 {
        while (!down_write_trylock(sem))
-               msleep(10);
+               fsleep(10000);
 }

 static void cifsFileInfo_put_work(struct work_struct *work);

@@ -2828,7 +2828,7 @@ size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)

                        if (wsize < wdata->bytes) {
                                add_credits_and_wake_if(server, &credits, 0);
-                               msleep(1000);
+                               ssleep(1);
                        }
                } while (wsize < wdata->bytes);
                wdata->credits = credits;

@@ -3563,7 +3563,7 @@ static int cifs_resend_rdata(struct cifs_readdata *rdata,

                        if (rsize < rdata->bytes) {
                                add_credits_and_wake_if(server, &credits, 0);
-                               msleep(1000);
+                               ssleep(1);
                        }
                } while (rsize < rdata->bytes);
                rdata->credits = credits;

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index b029ed3..84f97f8 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c

@@ -1372,7 +1372,7 @@ void smbd_destroy(struct TCP_Server_Info *server)
        wake_up_interruptible_all(&info->wait_mr);
        while (atomic_read(&info->mr_used_count)) {
                mutex_unlock(&server->srv_mutex);
-               msleep(1000);
+               ssleep(1);
                mutex_lock(&server->srv_mutex);
        }
        destroy_mr_list(info);
--

1.9.1

--
Thanks,

Steve