errseq: Add to documentation tree

 - Move errseq.rst into core-api
 - Add errseq to the core-api index
 - Promote the header to a more prominent header type, otherwise we get three
   entries in the table of contents.
 - Reformat the table to look nicer and be a little more proportional in
   terms of horizontal width per bit (the SF bit is still disproportionately
   large, but there's no way to fix that).
 - Include errseq kernel-doc in the errseq.rst
 - Neaten some kernel-doc markup

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 21 insertions, 16 deletions

diff --git a/lib/errseq.c b/lib/errseq.c
index 79cc66897db4..df782418b333 100644
--- a/lib/errseq.c
+++ b/lib/errseq.c
@@ -46,14 +46,14 @@
  * @eseq: errseq_t field that should be set
  * @err: error to set (must be between -1 and -MAX_ERRNO)
  *
- * This function sets the error in *eseq, and increments the sequence counter
+ * This function sets the error in @eseq, and increments the sequence counter
  * if the last sequence was sampled at some point in the past.
  *
  * Any error set will always overwrite an existing error.
  *
- * We do return the latest value here, primarily for debugging purposes. The
- * return value should not be used as a previously sampled value in later calls
- * as it will not have the SEEN flag set.
+ * Return: The previous value, primarily for debugging purposes. The
+ * return value should not be used as a previously sampled value in later
+ * calls as it will not have the SEEN flag set.
  */
 errseq_t errseq_set(errseq_t *eseq, int err)
 {
@@ -108,11 +108,13 @@ errseq_t errseq_set(errseq_t *eseq, int err)
 EXPORT_SYMBOL(errseq_set);
 
 /**
- * errseq_sample - grab current errseq_t value
- * @eseq: pointer to errseq_t to be sampled
+ * errseq_sample() - Grab current errseq_t value.
+ * @eseq: Pointer to errseq_t to be sampled.
  *
  * This function allows callers to sample an errseq_t value, marking it as
  * "seen" if required.
+ *
+ * Return: The current errseq value.
  */
 errseq_t errseq_sample(errseq_t *eseq)
 {
@@ -134,15 +136,15 @@ errseq_t errseq_sample(errseq_t *eseq)
 EXPORT_SYMBOL(errseq_sample);
 
 /**
- * errseq_check - has an error occurred since a particular sample point?
- * @eseq: pointer to errseq_t value to be checked
- * @since: previously-sampled errseq_t from which to check
+ * errseq_check() - Has an error occurred since a particular sample point?
+ * @eseq: Pointer to errseq_t value to be checked.
+ * @since: Previously-sampled errseq_t from which to check.
  *
- * Grab the value that eseq points to, and see if it has changed "since"
- * the given value was sampled. The "since" value is not advanced, so there
+ * Grab the value that eseq points to, and see if it has changed @since
+ * the given value was sampled. The @since value is not advanced, so there
  * is no need to mark the value as seen.
  *
- * Returns the latest error set in the errseq_t or 0 if it hasn't changed.
+ * Return: The latest error set in the errseq_t or 0 if it hasn't changed.
  */
 int errseq_check(errseq_t *eseq, errseq_t since)
 {
@@ -155,11 +157,11 @@ int errseq_check(errseq_t *eseq, errseq_t since)
 EXPORT_SYMBOL(errseq_check);
 
 /**
- * errseq_check_and_advance - check an errseq_t and advance to current value
- * @eseq: pointer to value being checked and reported
- * @since: pointer to previously-sampled errseq_t to check against and advance
+ * errseq_check_and_advance() - Check an errseq_t and advance to current value.
+ * @eseq: Pointer to value being checked and reported.
+ * @since: Pointer to previously-sampled errseq_t to check against and advance.
  *
- * Grab the eseq value, and see whether it matches the value that "since"
+ * Grab the eseq value, and see whether it matches the value that @since
  * points to. If it does, then just return 0.
  *
  * If it doesn't, then the value has changed. Set the "seen" flag, and try to
@@ -170,6 +172,9 @@ EXPORT_SYMBOL(errseq_check);
  * value. The caller must provide that if necessary. Because of this, callers
  * may want to do a lockless errseq_check before taking the lock and calling
  * this.
+ *
+ * Return: Negative errno if one has been stored, or 0 if no new error has
+ * occurred.
  */
 int errseq_check_and_advance(errseq_t *eseq, errseq_t *since)
 {