On Tue, Mar 19, 2024 at 09:46:00AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> The count is used purely to allocate the correct number of bvecs for
> submitting IO. Rename it to b_bvec_count.
Well, I think we should just kill it as it simplies is the rounded
up length in PAGE_SIZE units. The patch below passes a quick xfstests
run and is on top of this series:
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 2a6796c48454f7..8ecf88b5504c18 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -67,27 +67,17 @@ static inline bool xfs_buf_is_uncached(struct xfs_buf *bp)
}
/*
- * Return true if the buffer is vmapped.
- *
- * b_addr is always set, so we have to look at bp->b_bvec_count to determine if
- * the buffer was vmalloc()d or not.
+ * See comment above xfs_buf_alloc_folios() about the constraints placed on
+ * allocating vmapped buffers.
*/
-static inline int
-xfs_buf_is_vmapped(
- struct xfs_buf *bp)
+static inline unsigned int xfs_buf_vmap_len(struct xfs_buf *bp)
{
- return bp->b_bvec_count > 1;
+ return roundup(BBTOB(bp->b_length), PAGE_SIZE);
}
-/*
- * See comment above xfs_buf_alloc_folios() about the constraints placed on
- * allocating vmapped buffers.
- */
-static inline int
-xfs_buf_vmap_len(
- struct xfs_buf *bp)
+static inline unsigned int xfs_buf_nr_pages(struct xfs_buf *bp)
{
- return (bp->b_bvec_count * PAGE_SIZE);
+ return DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE);
}
/*
@@ -304,13 +294,15 @@ xfs_buf_free(
goto free;
}
- if (!(bp->b_flags & _XBF_KMEM))
- mm_account_reclaimed_pages(bp->b_bvec_count);
-
- if (bp->b_flags & _XBF_FOLIOS)
- __folio_put(kmem_to_folio(bp->b_addr));
- else
+ if (bp->b_flags & _XBF_FOLIOS) {
+ /* XXX: should this pass xfs_buf_nr_pages()? */
+ mm_account_reclaimed_pages(1);
+ folio_put(kmem_to_folio(bp->b_addr));
+ } else {
+ if (!(bp->b_flags & _XBF_KMEM))
+ mm_account_reclaimed_pages(xfs_buf_nr_pages(bp));
kvfree(bp->b_addr);
+ }
bp->b_flags &= _XBF_KMEM | _XBF_FOLIOS;
@@ -341,7 +333,6 @@ xfs_buf_alloc_kmem(
bp->b_addr = NULL;
return -ENOMEM;
}
- bp->b_bvec_count = 1;
bp->b_flags |= _XBF_KMEM;
return 0;
}
@@ -369,7 +360,6 @@ xfs_buf_alloc_folio(
return false;
bp->b_addr = folio_address(folio);
- bp->b_bvec_count = 1;
bp->b_flags |= _XBF_FOLIOS;
return true;
}
@@ -441,7 +431,6 @@ xfs_buf_alloc_folios(
count);
return -ENOMEM;
}
- bp->b_bvec_count = count;
return 0;
}
@@ -1470,7 +1459,9 @@ xfs_buf_bio_end_io(
cmpxchg(&bp->b_io_error, 0, error);
}
- if (!bp->b_error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ))
+ if (!bp->b_error &&
+ (bp->b_flags & XBF_READ) &&
+ is_vmalloc_addr(bp->b_addr))
invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp));
if (atomic_dec_and_test(&bp->b_io_remaining) == 1)
@@ -1485,6 +1476,7 @@ xfs_buf_ioapply_map(
unsigned int *buf_offset,
blk_opf_t op)
{
+ unsigned int nr_vecs = 1;
struct bio *bio;
int size;
@@ -1494,7 +1486,9 @@ xfs_buf_ioapply_map(
atomic_inc(&bp->b_io_remaining);
- bio = bio_alloc(bp->b_target->bt_bdev, bp->b_bvec_count, op, GFP_NOIO);
+ if (is_vmalloc_addr(bp->b_addr))
+ nr_vecs = xfs_buf_nr_pages(bp);
+ bio = bio_alloc(bp->b_target->bt_bdev, nr_vecs, op, GFP_NOIO);
bio->bi_iter.bi_sector = bp->b_maps[map].bm_bn;
bio->bi_end_io = xfs_buf_bio_end_io;
bio->bi_private = bp;
@@ -1511,7 +1505,7 @@ xfs_buf_ioapply_map(
*buf_offset += len;
} while (size);
- if (xfs_buf_is_vmapped(bp))
+ if (is_vmalloc_addr(bp->b_addr))
flush_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp));
submit_bio(bio);
}
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 32688525890bec..ad92d11f4ae173 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -195,7 +195,6 @@ struct xfs_buf {
int b_map_count;
atomic_t b_pin_count; /* pin count */
atomic_t b_io_remaining; /* #outstanding I/O requests */
- unsigned int b_bvec_count; /* bvecs needed for IO */
int b_error; /* error code on I/O */
/*
diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
index 30d53ddd6e6980..f082b1a64fc950 100644
--- a/fs/xfs/xfs_buf_mem.c
+++ b/fs/xfs/xfs_buf_mem.c
@@ -169,7 +169,6 @@ xmbuf_map_folio(
unlock_page(page);
bp->b_addr = page_address(page);
- bp->b_bvec_count = 1;
return 0;
}
@@ -182,7 +181,6 @@ xmbuf_unmap_folio(
folio_put(kmem_to_folio(bp->b_addr));
bp->b_addr = NULL;
- bp->b_bvec_count = 0;
}
/* Is this a valid daddr within the buftarg? */
