block: rename __bio_add_pc_page to bio_add_hw_page

[linux.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 21cbaa6a1c20e93cdadb8e1b9678391b0d36e368..aad0a6dad4f9bf8aec8c577583f1a98c10743fa7 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -748,9 +748,14 @@ static inline bool page_is_mergeable(const struct bio_vec *bv,
        return true;
 }
 
-static bool bio_try_merge_pc_page(struct request_queue *q, struct bio *bio,
-               struct page *page, unsigned len, unsigned offset,
-               bool *same_page)
+/*
+ * Try to merge a page into a segment, while obeying the hardware segment
+ * size limit.  This is not for normal read/write bios, but for passthrough
+ * or Zone Append operations that we can't split.
+ */
+static bool bio_try_merge_hw_seg(struct request_queue *q, struct bio *bio,
+                                struct page *page, unsigned len,
+                                unsigned offset, bool *same_page)
 {
        struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
        unsigned long mask = queue_segment_boundary(q);
@@ -765,38 +770,32 @@ static bool bio_try_merge_pc_page(struct request_queue *q, struct bio *bio,
 }
 
 /**
- *     __bio_add_pc_page       - attempt to add page to passthrough bio
- *     @q: the target queue
- *     @bio: destination bio
- *     @page: page to add
- *     @len: vec entry length
- *     @offset: vec entry offset
- *     @same_page: return if the merge happen inside the same page
- *
- *     Attempt to add a page to the bio_vec maplist. This can fail for a
- *     number of reasons, such as the bio being full or target block device
- *     limitations. The target block device must allow bio's up to PAGE_SIZE,
- *     so it is always possible to add a single page to an empty bio.
+ * bio_add_hw_page - attempt to add a page to a bio with hw constraints
+ * @q: the target queue
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ * @max_sectors: maximum number of sectors that can be added
+ * @same_page: return if the segment has been merged inside the same page
  *
- *     This should only be used by passthrough bios.
+ * Add a page to a bio while respecting the hardware max_sectors, max_segment
+ * and gap limitations.
  */
-int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
+int bio_add_hw_page(struct request_queue *q, struct bio *bio,
                struct page *page, unsigned int len, unsigned int offset,
-               bool *same_page)
+               unsigned int max_sectors, bool *same_page)
 {
        struct bio_vec *bvec;
 
-       /*
-        * cloned bio must not modify vec list
-        */
-       if (unlikely(bio_flagged(bio, BIO_CLONED)))
+       if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
                return 0;
 
-       if (((bio->bi_iter.bi_size + len) >> 9) > queue_max_hw_sectors(q))
+       if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
                return 0;
 
        if (bio->bi_vcnt > 0) {
-               if (bio_try_merge_pc_page(q, bio, page, len, offset, same_page))
+               if (bio_try_merge_hw_seg(q, bio, page, len, offset, same_page))
                        return len;
 
                /*
@@ -823,11 +822,27 @@ int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
        return len;
 }
 
+/**
+ * bio_add_pc_page     - attempt to add page to passthrough bio
+ * @q: the target queue
+ * @bio: destination bio
+ * @page: page to add
+ * @len: vec entry length
+ * @offset: vec entry offset
+ *
+ * Attempt to add a page to the bio_vec maplist. This can fail for a
+ * number of reasons, such as the bio being full or target block device
+ * limitations. The target block device must allow bio's up to PAGE_SIZE,
+ * so it is always possible to add a single page to an empty bio.
+ *
+ * This should only be used by passthrough bios.
+ */
 int bio_add_pc_page(struct request_queue *q, struct bio *bio,
                struct page *page, unsigned int len, unsigned int offset)
 {
        bool same_page = false;
-       return __bio_add_pc_page(q, bio, page, len, offset, &same_page);
+       return bio_add_hw_page(q, bio, page, len, offset,
+                       queue_max_hw_sectors(q), &same_page);
 }
 EXPORT_SYMBOL(bio_add_pc_page);