diff options
| -rw-r--r-- | fs/xfs/xfs_buf.c | 48 |
1 files changed, 24 insertions, 24 deletions
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 18ec1c1fbca1..acf19b5221bf 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -243,23 +243,23 @@ xfs_buf_free( static int xfs_buf_alloc_kmem( - struct xfs_buf *bp, - xfs_buf_flags_t flags) + struct xfs_buf *bp, + size_t size, + gfp_t gfp_mask) { - gfp_t gfp_mask = GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL; - size_t size = BBTOB(bp->b_length); - - /* Assure zeroed buffer for non-read cases. */ - if (!(flags & XBF_READ)) - gfp_mask |= __GFP_ZERO; + ASSERT(is_power_of_2(size)); + ASSERT(size < PAGE_SIZE); - bp->b_addr = kmalloc(size, gfp_mask); + bp->b_addr = kmalloc(size, gfp_mask | __GFP_NOFAIL); if (!bp->b_addr) return -ENOMEM; - if (((unsigned long)(bp->b_addr + size - 1) & PAGE_MASK) != - ((unsigned long)bp->b_addr & PAGE_MASK)) { - /* b_addr spans two pages - use alloc_page instead */ + /* + * Slab guarantees that we get back naturally aligned allocations for + * power of two sizes. Keep this check as the canary in the coal mine + * if anything changes in slab. + */ + if (WARN_ON_ONCE(!IS_ALIGNED((unsigned long)bp->b_addr, size))) { kfree(bp->b_addr); bp->b_addr = NULL; return -ENOMEM; @@ -300,18 +300,22 @@ xfs_buf_alloc_backing_mem( if (xfs_buftarg_is_mem(bp->b_target)) return xmbuf_map_page(bp); - /* - * For buffers that fit entirely within a single page, first attempt to - * allocate the memory from the heap to minimise memory usage. If we - * can't get heap memory for these small buffers, we fall back to using - * the page allocator. - */ - if (size < PAGE_SIZE && xfs_buf_alloc_kmem(new_bp, flags) == 0) - return 0; + /* Assure zeroed buffer for non-read cases. */ + if (!(flags & XBF_READ)) + gfp_mask |= __GFP_ZERO; if (flags & XBF_READ_AHEAD) gfp_mask |= __GFP_NORETRY; + /* + * For buffers smaller than PAGE_SIZE use a kmalloc allocation if that + * is properly aligned. The slab allocator now guarantees an aligned + * allocation for all power of two sizes, which matches most of the + * smaller than PAGE_SIZE buffers used by XFS. + */ + if (size < PAGE_SIZE && is_power_of_2(size)) + return xfs_buf_alloc_kmem(bp, size, gfp_mask); + /* Make sure that we have a page list */ bp->b_page_count = DIV_ROUND_UP(size, PAGE_SIZE); if (bp->b_page_count <= XB_PAGES) { @@ -324,10 +328,6 @@ xfs_buf_alloc_backing_mem( } bp->b_flags |= _XBF_PAGES; - /* Assure zeroed buffer for non-read cases. */ - if (!(flags & XBF_READ)) - gfp_mask |= __GFP_ZERO; - /* * Bulk filling of pages can take multiple calls. Not filling the entire * array is not an allocation failure, so don't back off if we get at |