ceph: move sb->wb_pagevec_pool to be a global mempool

When doing some testing recently, I hit some page allocation failures
on mount, when creating the wb_pagevec_pool for the mount. That
requires 128k (32 contiguous pages), and after thrashing the memory
during an xfstests run, sometimes that would fail.

128k for each mount seems like a lot to hold in reserve for a rainy
day, so let's change this to a global mempool that gets allocated
when the module is plugged in.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 8 insertions, 14 deletions

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 585aecea5cad..7ec0e6d03d10 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -637,8 +637,6 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 					struct ceph_options *opt)
 {
 	struct ceph_fs_client *fsc;
-	int page_count;
-	size_t size;
 	int err;
 
 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
@@ -686,22 +684,12 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 	if (!fsc->cap_wq)
 		goto fail_inode_wq;
 
-	/* set up mempools */
-	err = -ENOMEM;
-	page_count = fsc->mount_options->wsize >> PAGE_SHIFT;
-	size = sizeof (struct page *) * (page_count ? page_count : 1);
-	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, size);
-	if (!fsc->wb_pagevec_pool)
-		goto fail_cap_wq;
-
 	spin_lock(&ceph_fsc_lock);
 	list_add_tail(&fsc->metric_wakeup, &ceph_fsc_list);
 	spin_unlock(&ceph_fsc_lock);
 
 	return fsc;
 
-fail_cap_wq:
-	destroy_workqueue(fsc->cap_wq);
 fail_inode_wq:
 	destroy_workqueue(fsc->inode_wq);
 fail_client:
@@ -732,8 +720,6 @@ static void destroy_fs_client(struct ceph_fs_client *fsc)
 	destroy_workqueue(fsc->inode_wq);
 	destroy_workqueue(fsc->cap_wq);
 
-	mempool_destroy(fsc->wb_pagevec_pool);
-
 	destroy_mount_options(fsc->mount_options);
 
 	ceph_destroy_client(fsc->client);
@@ -752,6 +738,7 @@ struct kmem_cache *ceph_dentry_cachep;
 struct kmem_cache *ceph_file_cachep;
 struct kmem_cache *ceph_dir_file_cachep;
 struct kmem_cache *ceph_mds_request_cachep;
+mempool_t *ceph_wb_pagevec_pool;
 
 static void ceph_inode_init_once(void *foo)
 {
@@ -796,6 +783,10 @@ static int __init init_caches(void)
 	if (!ceph_mds_request_cachep)
 		goto bad_mds_req;
 
+	ceph_wb_pagevec_pool = mempool_create_kmalloc_pool(10, CEPH_MAX_WRITE_SIZE >> PAGE_SHIFT);
+	if (!ceph_wb_pagevec_pool)
+		goto bad_pagevec_pool;
+
 	error = ceph_fscache_register();
 	if (error)
 		goto bad_fscache;
@@ -804,6 +795,8 @@ static int __init init_caches(void)
 
 bad_fscache:
 	kmem_cache_destroy(ceph_mds_request_cachep);
+bad_pagevec_pool:
+	mempool_destroy(ceph_wb_pagevec_pool);
 bad_mds_req:
 	kmem_cache_destroy(ceph_dir_file_cachep);
 bad_dir_file:
@@ -834,6 +827,7 @@ static void destroy_caches(void)
 	kmem_cache_destroy(ceph_file_cachep);
 	kmem_cache_destroy(ceph_dir_file_cachep);
 	kmem_cache_destroy(ceph_mds_request_cachep);
+	mempool_destroy(ceph_wb_pagevec_pool);
 
 	ceph_fscache_unregister();
 }