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.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
fs/xfs/xfs_buf.c | 38 +++++++++++++++++++++-----------------
fs/xfs/xfs_buf.h | 2 +-
fs/xfs/xfs_buf_mem.c | 4 ++--
3 files changed, 24 insertions(+), 20 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 6d6bad80722e..2a6796c48454 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -69,15 +69,14 @@ static inline bool xfs_buf_is_uncached(struct xfs_buf *bp)
/*
* Return true if the buffer is vmapped.
*
- * b_addr is null if the buffer is not mapped, but the code is clever enough to
- * know it doesn't have to map a single folio, so the check has to be both for
- * b_addr and bp->b_folio_count > 1.
+ * 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.
*/
static inline int
xfs_buf_is_vmapped(
struct xfs_buf *bp)
{
- return bp->b_addr && bp->b_folio_count > 1;
+ return bp->b_bvec_count > 1;
}
/*
@@ -88,7 +87,7 @@ static inline int
xfs_buf_vmap_len(
struct xfs_buf *bp)
{
- return (bp->b_folio_count * PAGE_SIZE);
+ return (bp->b_bvec_count * PAGE_SIZE);
}
/*
@@ -306,7 +305,7 @@ xfs_buf_free(
}
if (!(bp->b_flags & _XBF_KMEM))
- mm_account_reclaimed_pages(bp->b_folio_count);
+ mm_account_reclaimed_pages(bp->b_bvec_count);
if (bp->b_flags & _XBF_FOLIOS)
__folio_put(kmem_to_folio(bp->b_addr));
@@ -342,7 +341,7 @@ xfs_buf_alloc_kmem(
bp->b_addr = NULL;
return -ENOMEM;
}
- bp->b_folio_count = 1;
+ bp->b_bvec_count = 1;
bp->b_flags |= _XBF_KMEM;
return 0;
}
@@ -370,7 +369,7 @@ xfs_buf_alloc_folio(
return false;
bp->b_addr = folio_address(folio);
- bp->b_folio_count = 1;
+ bp->b_bvec_count = 1;
bp->b_flags |= _XBF_FOLIOS;
return true;
}
@@ -398,6 +397,7 @@ xfs_buf_alloc_folios(
{
gfp_t gfp_mask = GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOWARN;
unsigned nofs_flag;
+ unsigned int count;
if (flags & XBF_READ_AHEAD)
gfp_mask |= __GFP_NORETRY;
@@ -407,16 +407,24 @@ xfs_buf_alloc_folios(
gfp_mask |= __GFP_ZERO;
/* Fall back to allocating an array of single page folios. */
- bp->b_folio_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE);
+ count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE);
/* Optimistically attempt a single high order folio allocation. */
if (xfs_buf_alloc_folio(bp, gfp_mask))
return 0;
/* We are done if an order-0 allocation has already failed. */
- if (bp->b_folio_count == 1)
+ if (count == 1)
return -ENOMEM;
+ /*
+ * Largest buffer we allocate should fit entirely in a single bio,
+ * so warn and fail if somebody asks for a buffer larger than can
+ * be supported.
+ */
+ if (WARN_ON_ONCE(count > BIO_MAX_VECS))
+ return -EIO;
+
/*
* XXX(dgc): I think dquot reclaim is the only place we can get
* to this function from memory reclaim context now. If we fix
@@ -430,9 +438,10 @@ xfs_buf_alloc_folios(
if (!bp->b_addr) {
xfs_warn_ratelimited(bp->b_mount,
"%s: failed to allocate %u folios", __func__,
- bp->b_folio_count);
+ count);
return -ENOMEM;
}
+ bp->b_bvec_count = count;
return 0;
}
@@ -1483,14 +1492,9 @@ xfs_buf_ioapply_map(
size = min_t(unsigned int, BBTOB(bp->b_maps[map].bm_len),
BBTOB(bp->b_length) - *buf_offset);
- if (WARN_ON_ONCE(bp->b_folio_count > BIO_MAX_VECS)) {
- xfs_buf_ioerror(bp, -EIO);
- return;
- }
-
atomic_inc(&bp->b_io_remaining);
- bio = bio_alloc(bp->b_target->bt_bdev, bp->b_folio_count, op, GFP_NOIO);
+ bio = bio_alloc(bp->b_target->bt_bdev, bp->b_bvec_count, 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;
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 68c24947ca1a..32688525890b 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -195,7 +195,7 @@ 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_folio_count; /* size of folio array */
+ 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 336e7c8effb7..30d53ddd6e69 100644
--- a/fs/xfs/xfs_buf_mem.c
+++ b/fs/xfs/xfs_buf_mem.c
@@ -169,7 +169,7 @@ xmbuf_map_folio(
unlock_page(page);
bp->b_addr = page_address(page);
- bp->b_folio_count = 1;
+ bp->b_bvec_count = 1;
return 0;
}
@@ -182,7 +182,7 @@ xmbuf_unmap_folio(
folio_put(kmem_to_folio(bp->b_addr));
bp->b_addr = NULL;
- bp->b_folio_count = 0;
+ bp->b_bvec_count = 0;
}
/* Is this a valid daddr within the buftarg? */
--
2.43.0
