From cd36001bd8fbcf1664bfba1b33c383f8033fe6ce Mon Sep 17 00:00:00 2001 From: "John L. Hammond" Date: Fri, 10 Nov 2017 11:00:58 -0600 Subject: [PATCH] LU-10218 mdc: propagate changelog errors to readers 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 l_wait_event() with wait_event_interruptible(). Signed-off-by: John L. Hammond Change-Id: I279ec8ca11bfeb67f844acf12e3f7cba8f8aa1e6 Reviewed-on: https://review.whamcloud.com/30040 Tested-by: Jenkins Reviewed-by: Quentin Bouget Tested-by: Maloo Reviewed-by: Henri Doreau Reviewed-by: Oleg Drokin --- lustre/mdc/mdc_changelog.c | 50 +++++++++++++++++++++++++++------------------- 1 file changed, 29 insertions(+), 21 deletions(-) diff --git a/lustre/mdc/mdc_changelog.c b/lustre/mdc/mdc_changelog.c index 8431b1c..9849220 100644 --- a/lustre/mdc/mdc_changelog.c +++ b/lustre/mdc/mdc_changelog.c @@ -72,7 +72,7 @@ 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 */ @@ -122,7 +122,6 @@ static int chlg_read_cat_process_cb(const struct lu_env *env, struct llog_changelog_rec *rec; struct chlg_reader_state *crs = data; struct chlg_rec_entry *enq; - struct l_wait_info lwi = { 0 }; size_t len; int rc; ENTRY; @@ -152,9 +151,9 @@ 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)); - l_wait_event(crs->crs_waitq_prod, - (crs->crs_rec_count < CDEV_CHLG_MAX_PREFETCH || - kthread_should_stop()), &lwi); + 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); @@ -200,7 +199,6 @@ static int chlg_load(void *args) struct obd_device *obd = crs->crs_obd; struct llog_ctxt *ctx = NULL; struct llog_handle *llh = NULL; - struct l_wait_info lwi = { 0 }; int rc; ENTRY; @@ -233,7 +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); @@ -243,7 +241,7 @@ err_out: if (ctx != NULL) llog_ctxt_put(ctx); - l_wait_event(crs->crs_waitq_prod, kthread_should_stop(), &lwi); + wait_event_interruptible(crs->crs_waitq_prod, kthread_should_stop()); RETURN(rc); } @@ -266,17 +264,22 @@ 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; - struct l_wait_info lwi = { 0 }; - ssize_t written_total = 0; + size_t written_total = 0; + ssize_t rc; LIST_HEAD(consumed); ENTRY; - if (file->f_flags & O_NONBLOCK && crs->crs_rec_count == 0) - RETURN(-EAGAIN); + 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); + } - l_wait_event(crs->crs_waitq_cons, - crs->crs_rec_count > 0 || crs->crs_eof || crs->crs_err, - &lwi); + rc = wait_event_interruptible(crs->crs_waitq_cons, + crs->crs_rec_count > 0 || crs->crs_eof || crs->crs_err); mutex_lock(&crs->crs_lock); list_for_each_entry_safe(rec, tmp, &crs->crs_rec_queue, enq_linkage) { @@ -284,8 +287,7 @@ 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; } @@ -299,15 +301,19 @@ 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); } /** @@ -536,15 +542,17 @@ 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); OBD_FREE_PTR(crs); - return 0; + + return rc; } /** -- 1.8.3.1