| Message ID | 1543200508-6838-9-git-send-email-jsimmons@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lustre: new patches to address previous reviews | expand |
On Sun, Nov 25 2018, James Simmons wrote: > From: "John L. Hammond" <jhammond@whamcloud.com> > > Store errors encountered by the changelog llog reader thread in the > crs_err field of struct changelog_reader_state so that they can be > propageted to changelog readers. In chlg_read() improve the error and > EOF reporting. Return -ERESTARTSYS when the blocked reader is > interrupted. Replace uses of wait_event_idle() with > ait_event_interruptible(). > > Signed-off-by: John L. Hammond <jhammond@whamcloud.com> > WC-bug-id: https://jira.whamcloud.com/browse/LU-10218 > Reviewed-on: https://review.whamcloud.com/30040 > Reviewed-by: Quentin Bouget <quentin.bouget@cea.fr> > Reviewed-by: Henri Doreau <henri.doreau@cea.fr> > Reviewed-by: Oleg Drokin <green@whamcloud.com> > Signed-off-by: James Simmons <jsimmons@infradead.org> > --- > drivers/staging/lustre/lustre/mdc/mdc_changelog.c | 45 ++++++++++++++--------- > 1 file changed, 28 insertions(+), 17 deletions(-) > > diff --git a/drivers/staging/lustre/lustre/mdc/mdc_changelog.c b/drivers/staging/lustre/lustre/mdc/mdc_changelog.c > index becdee8..811a36a 100644 > --- a/drivers/staging/lustre/lustre/mdc/mdc_changelog.c > +++ b/drivers/staging/lustre/lustre/mdc/mdc_changelog.c > @@ -71,7 +71,7 @@ struct chlg_reader_state { > /* Producer thread (if any) */ > struct task_struct *crs_prod_task; > /* An error occurred that prevents from reading further */ > - bool crs_err; > + int crs_err; > /* EOF, no more records available */ > bool crs_eof; > /* Desired start position */ > @@ -148,9 +148,9 @@ static int chlg_read_cat_process_cb(const struct lu_env *env, > PFID(&rec->cr.cr_tfid), PFID(&rec->cr.cr_pfid), > rec->cr.cr_namelen, changelog_rec_name(&rec->cr)); > > - wait_event_idle(crs->crs_waitq_prod, > - (crs->crs_rec_count < CDEV_CHLG_MAX_PREFETCH || > - kthread_should_stop())); > + wait_event_interruptible(crs->crs_waitq_prod, > + crs->crs_rec_count < CDEV_CHLG_MAX_PREFETCH || > + kthread_should_stop()); This is wrong. Not harmful, but wrong. This is in a kernel thread, so it doesn't expect to receive signals. So allowing an abort on a signal is pointless and misleading. So I've removed this chunk from the patch, and also a later chunk which uses wait_event_interruptible() in a kthread. Other places where wait_event_interruptible() are used make sense. Thanks, NeilBrown > > if (kthread_should_stop()) > return LLOG_PROC_BREAK; > @@ -231,7 +231,7 @@ static int chlg_load(void *args) > > err_out: > if (rc < 0) > - crs->crs_err = true; > + crs->crs_err = rc; > > wake_up_all(&crs->crs_waitq_cons); > > @@ -241,7 +241,7 @@ static int chlg_load(void *args) > if (ctx) > llog_ctxt_put(ctx); > > - wait_event_idle(crs->crs_waitq_prod, kthread_should_stop()); > + wait_event_interruptible(crs->crs_waitq_prod, kthread_should_stop()); > > return rc; > } > @@ -264,13 +264,20 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, > struct chlg_reader_state *crs = file->private_data; > struct chlg_rec_entry *rec; > struct chlg_rec_entry *tmp; > - ssize_t written_total = 0; > + ssize_t written_total = 0; > LIST_HEAD(consumed); > + size_t rc; > + > + if (file->f_flags & O_NONBLOCK && crs->crs_rec_count == 0) { > + if (crs->crs_err < 0) > + return crs->crs_err; > + else if (crs->crs_eof) > + return 0; > + else > + return -EAGAIN; > + } > > - if (file->f_flags & O_NONBLOCK && crs->crs_rec_count == 0) > - return -EAGAIN; > - > - wait_event_idle(crs->crs_waitq_cons, > + rc = wait_event_interruptible(crs->crs_waitq_cons, > crs->crs_rec_count > 0 || crs->crs_eof || crs->crs_err); > > mutex_lock(&crs->crs_lock); > @@ -279,8 +286,7 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, > break; > > if (copy_to_user(buff, rec->enq_record, rec->enq_length)) { > - if (written_total == 0) > - written_total = -EFAULT; > + rc = -EFAULT; > break; > } > > @@ -294,15 +300,19 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, > } > mutex_unlock(&crs->crs_lock); > > - if (written_total > 0) > + if (written_total > 0) { > + rc = written_total; > wake_up_all(&crs->crs_waitq_prod); > + } else if (rc == 0) { > + rc = crs->crs_err; > + } > > list_for_each_entry_safe(rec, tmp, &consumed, enq_linkage) > enq_record_delete(rec); > > *ppos = crs->crs_start_offset; > > - return written_total; > + return rc; > } > > /** > @@ -509,15 +519,16 @@ static int chlg_release(struct inode *inode, struct file *file) > struct chlg_reader_state *crs = file->private_data; > struct chlg_rec_entry *rec; > struct chlg_rec_entry *tmp; > + int rc = 0; > > if (crs->crs_prod_task) > - kthread_stop(crs->crs_prod_task); > + rc = kthread_stop(crs->crs_prod_task); > > list_for_each_entry_safe(rec, tmp, &crs->crs_rec_queue, enq_linkage) > enq_record_delete(rec); > > kfree(crs); > - return 0; > + return rc; > } > > /** > -- > 1.8.3.1
diff --git a/drivers/staging/lustre/lustre/mdc/mdc_changelog.c b/drivers/staging/lustre/lustre/mdc/mdc_changelog.c index becdee8..811a36a 100644 --- a/drivers/staging/lustre/lustre/mdc/mdc_changelog.c +++ b/drivers/staging/lustre/lustre/mdc/mdc_changelog.c @@ -71,7 +71,7 @@ struct chlg_reader_state { /* Producer thread (if any) */ struct task_struct *crs_prod_task; /* An error occurred that prevents from reading further */ - bool crs_err; + int crs_err; /* EOF, no more records available */ bool crs_eof; /* Desired start position */ @@ -148,9 +148,9 @@ static int chlg_read_cat_process_cb(const struct lu_env *env, PFID(&rec->cr.cr_tfid), PFID(&rec->cr.cr_pfid), rec->cr.cr_namelen, changelog_rec_name(&rec->cr)); - wait_event_idle(crs->crs_waitq_prod, - (crs->crs_rec_count < CDEV_CHLG_MAX_PREFETCH || - kthread_should_stop())); + wait_event_interruptible(crs->crs_waitq_prod, + crs->crs_rec_count < CDEV_CHLG_MAX_PREFETCH || + kthread_should_stop()); if (kthread_should_stop()) return LLOG_PROC_BREAK; @@ -231,7 +231,7 @@ static int chlg_load(void *args) err_out: if (rc < 0) - crs->crs_err = true; + crs->crs_err = rc; wake_up_all(&crs->crs_waitq_cons); @@ -241,7 +241,7 @@ static int chlg_load(void *args) if (ctx) llog_ctxt_put(ctx); - wait_event_idle(crs->crs_waitq_prod, kthread_should_stop()); + wait_event_interruptible(crs->crs_waitq_prod, kthread_should_stop()); return rc; } @@ -264,13 +264,20 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, struct chlg_reader_state *crs = file->private_data; struct chlg_rec_entry *rec; struct chlg_rec_entry *tmp; - ssize_t written_total = 0; + ssize_t written_total = 0; LIST_HEAD(consumed); + size_t rc; + + if (file->f_flags & O_NONBLOCK && crs->crs_rec_count == 0) { + if (crs->crs_err < 0) + return crs->crs_err; + else if (crs->crs_eof) + return 0; + else + return -EAGAIN; + } - if (file->f_flags & O_NONBLOCK && crs->crs_rec_count == 0) - return -EAGAIN; - - wait_event_idle(crs->crs_waitq_cons, + rc = wait_event_interruptible(crs->crs_waitq_cons, crs->crs_rec_count > 0 || crs->crs_eof || crs->crs_err); mutex_lock(&crs->crs_lock); @@ -279,8 +286,7 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, break; if (copy_to_user(buff, rec->enq_record, rec->enq_length)) { - if (written_total == 0) - written_total = -EFAULT; + rc = -EFAULT; break; } @@ -294,15 +300,19 @@ static ssize_t chlg_read(struct file *file, char __user *buff, size_t count, } mutex_unlock(&crs->crs_lock); - if (written_total > 0) + if (written_total > 0) { + rc = written_total; wake_up_all(&crs->crs_waitq_prod); + } else if (rc == 0) { + rc = crs->crs_err; + } list_for_each_entry_safe(rec, tmp, &consumed, enq_linkage) enq_record_delete(rec); *ppos = crs->crs_start_offset; - return written_total; + return rc; } /** @@ -509,15 +519,16 @@ static int chlg_release(struct inode *inode, struct file *file) struct chlg_reader_state *crs = file->private_data; struct chlg_rec_entry *rec; struct chlg_rec_entry *tmp; + int rc = 0; if (crs->crs_prod_task) - kthread_stop(crs->crs_prod_task); + rc = kthread_stop(crs->crs_prod_task); list_for_each_entry_safe(rec, tmp, &crs->crs_rec_queue, enq_linkage) enq_record_delete(rec); kfree(crs); - return 0; + return rc; } /**