[Drbd-dev] [PATCH 04/14] bdi: initialize ->ra_pages in bdi_init

Christoph Hellwig hch at lst.de
Mon Jul 20 09:51:38 CEST 2020


Set up a readahead size by default.  This changes behavior for mtd,
ubifs, and vboxsf to actually enabled readahead, the lack of which
very much looks like an oversight.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 block/blk-core.c   | 1 -
 fs/9p/vfs_super.c  | 4 ++--
 fs/afs/super.c     | 1 -
 fs/btrfs/disk-io.c | 1 -
 fs/fuse/inode.c    | 1 -
 fs/nfs/super.c     | 9 +--------
 mm/backing-dev.c   | 1 +
 7 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 93104c7470e8ac..ea1665de7a2079 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -538,7 +538,6 @@ struct request_queue *blk_alloc_queue(int node_id)
 	if (!q->stats)
 		goto fail_stats;
 
-	q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES;
 	q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
 	q->node = node_id;
 
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 74df32be4c6a52..a338eb979cadf9 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -80,8 +80,8 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 	if (ret)
 		return ret;
 
-	if (v9ses->cache)
-		sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
+	if (!v9ses->cache)
+		sb->s_bdi->ra_pages = 0;
 
 	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)
diff --git a/fs/afs/super.c b/fs/afs/super.c
index b552357b1d1379..3a40ee752c1e3f 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -456,7 +456,6 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 	ret = super_setup_bdi(sb);
 	if (ret)
 		return ret;
-	sb->s_bdi->ra_pages	= VM_READAHEAD_PAGES;
 
 	/* allocate the root inode and dentry */
 	if (as->dyn_root) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index eb5f2506cede72..67677207d1647d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3031,7 +3031,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	}
 
 	sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
-	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 5b4aebf5821fea..84fe187eb64385 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1037,7 +1037,6 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 	if (err)
 		return err;
 
-	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	/* fuse does it's own writeback accounting */
 	sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 7a70287f21a2c1..f943e37853fa25 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1200,13 +1200,6 @@ static void nfs_get_cache_cookie(struct super_block *sb,
 }
 #endif
 
-static void nfs_set_readahead(struct backing_dev_info *bdi,
-			      unsigned long iomax_pages)
-{
-	bdi->ra_pages = VM_READAHEAD_PAGES;
-	bdi->io_pages = iomax_pages;
-}
-
 int nfs_get_tree_common(struct fs_context *fc)
 {
 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
@@ -1251,7 +1244,7 @@ int nfs_get_tree_common(struct fs_context *fc)
 					     MINOR(server->s_dev));
 		if (error)
 			goto error_splat_super;
-		nfs_set_readahead(s->s_bdi, server->rpages);
+		s->s_bdi->io_pages = server->rpages;
 		server->super = s;
 	}
 
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 8e8b00627bb2d8..3e441e0ff1bc88 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -746,6 +746,7 @@ struct backing_dev_info *bdi_alloc(int node_id)
 		kfree(bdi);
 		return NULL;
 	}
+	bdi->ra_pages = VM_READAHEAD_PAGES;
 	return bdi;
 }
 EXPORT_SYMBOL(bdi_alloc);
-- 
2.27.0



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