xfs: can't use kmem_zalloc() for attribute buffers

Because heap allocation of 64kB buffers will fail:

....
 XFS: fs_mark(8414) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8417) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8409) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8428) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8430) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8437) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8433) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8406) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8412) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8432) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
 XFS: fs_mark(8424) possible memory allocation deadlock size 65768 in kmem_alloc (mode:0x2d40)
....

I'd use kvmalloc() instead, but....

- 48.19% xfs_attr_create_intent
  - 46.89% xfs_attri_init
     - kvmalloc_node
	- 46.04% __kmalloc_node
	   - kmalloc_large_node
	      - 45.99% __alloc_pages
		 - 39.39% __alloc_pages_slowpath.constprop.0
		    - 38.89% __alloc_pages_direct_compact
		       - 38.71% try_to_compact_pages
			  - compact_zone_order
			  - compact_zone
			     - 21.09% isolate_migratepages_block
				  10.31% PageHuge
				  5.82% set_pfnblock_flags_mask
				  0.86% get_pfnblock_flags_mask
			     - 4.48% __reset_isolation_suitable
				  4.44% __reset_isolation_pfn
			     - 3.56% __pageblock_pfn_to_page
				  1.33% pfn_to_online_page
			       2.83% get_pfnblock_flags_mask
			     - 0.87% migrate_pages
				  0.86% compaction_alloc
			       0.84% find_suitable_fallback
		 - 6.60% get_page_from_freelist
		      4.99% clear_page_erms
		    - 1.19% _raw_spin_lock_irqsave
		       - do_raw_spin_lock
			    __pv_queued_spin_lock_slowpath
	- 0.86% __vmalloc_node_range
	     0.65% __alloc_pages_bulk

.... this is just yet another reminder of how much kvmalloc() sucks.
So lift xlog_cil_kvmalloc(), rename it to xlog_kvmalloc() and use
that instead....

We also clean up the attribute name and value lengths as they no
longer need to be rounded out to sizes compatible with log vectors.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 15 insertions, 20 deletions

diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
index 56f678c965b7..e8ac88d9fd14 100644
--- a/fs/xfs/xfs_attr_item.c
+++ b/fs/xfs/xfs_attr_item.c
@@ -44,7 +44,7 @@ xfs_attri_item_free(
 	struct xfs_attri_log_item	*attrip)
 {
 	kmem_free(attrip->attri_item.li_lv_shadow);
-	kmem_free(attrip);
+	kvfree(attrip);
 }
 
 /*
@@ -119,11 +119,11 @@ xfs_attri_item_format(
 			sizeof(struct xfs_attri_log_format));
 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_NAME,
 			attrip->attri_name,
-			xlog_calc_iovec_len(attrip->attri_name_len));
+			attrip->attri_name_len);
 	if (attrip->attri_value_len > 0)
 		xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ATTR_VALUE,
 				attrip->attri_value,
-				xlog_calc_iovec_len(attrip->attri_value_len));
+				attrip->attri_value_len);
 }
 
 /*
@@ -163,26 +163,21 @@ xfs_attri_init(
 
 {
 	struct xfs_attri_log_item	*attrip;
-	uint32_t			name_vec_len = 0;
-	uint32_t			value_vec_len = 0;
-	uint32_t			buffer_size;
-
-	if (name_len)
-		name_vec_len = xlog_calc_iovec_len(name_len);
-	if (value_len)
-		value_vec_len = xlog_calc_iovec_len(value_len);
-
-	buffer_size = name_vec_len + value_vec_len;
+	uint32_t			buffer_size = name_len + value_len;
 
 	if (buffer_size) {
-		attrip = kmem_zalloc(sizeof(struct xfs_attri_log_item) +
-				    buffer_size, KM_NOFS);
-		if (attrip == NULL)
-			return NULL;
+		/*
+		 * This could be over 64kB in length, so we have to use
+		 * kvmalloc() for this. But kvmalloc() utterly sucks, so we
+		 * use own version.
+		 */
+		attrip = xlog_kvmalloc(sizeof(struct xfs_attri_log_item) +
+					buffer_size);
 	} else {
-		attrip = kmem_cache_zalloc(xfs_attri_cache,
-					  GFP_NOFS | __GFP_NOFAIL);
+		attrip = kmem_cache_alloc(xfs_attri_cache,
+					GFP_NOFS | __GFP_NOFAIL);
 	}
+	memset(attrip, 0, sizeof(struct xfs_attri_log_item));
 
 	attrip->attri_name_len = name_len;
 	if (name_len)
@@ -195,7 +190,7 @@ xfs_attri_init(
 	if (value_len)
 		attrip->attri_value = ((char *)attrip) +
 				sizeof(struct xfs_attri_log_item) +
-				name_vec_len;
+				name_len;
 	else
 		attrip->attri_value = NULL;