Commit e3aaf7f2 authored Aug 21, 2014 by Christoph Hellwig Committed by Trond Myklebust Sep 10, 2014

pnfs/blocklayout: reject pnfs blocksize larger than page size



The Linux VM subsystem can't support block sizes larger than page size
for block based filesystems very well.  While this can be hacked around
to some extent for simple filesystems the read-modify-write cycles
required for pnfs block invalid extents are extremly deadlock prone
when operating on multiple pages.  Reject this case early on instead
of pretending to support it (badly).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

parent 5f919c9f

fs/nfs/blocklayout/blocklayout.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1115,6 +1115,12 @@ bl_set_layoutdriver(struct nfs_server server, const struct nfs_fh fh)
		dprintk("%s Server did not return blksize\n", __func__);
		return -EINVAL;
		}
		if (server->pnfs_blksize > PAGE_SIZE) {
		printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
		__func__, server->pnfs_blksize);
		return -EINVAL;
		}

		b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS);
		if (!b_mt_id) {
		status = -ENOMEM;

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