Commit 5f919c9f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
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pnfs: allow splicing pre-encoded pages into the layoutcommit args 



Currently there is no XDR buffer space allocated for the per-layout driver
layoutcommit payload, which leads to server buffer overflows in the
blocklayout driver even under simple workloads.  As we can't do per-layout
sizes for XDR operations we'll have to splice a previously encoded list
of pages into the XDR stream, similar to how we handle ACL buffers.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 47abadef

fs/nfs/nfs4xdr.c

+13 −5
Original line number Diff line number Diff line
@@ -395,7 +395,10 @@ static int nfs4_stat_to_errno(int); 
				2 /* last byte written */ + \

				1 /* nt_timechanged (false) */ + \

				1 /* layoutupdate4 layout type */ + \

				1 /* NULL filelayout layoutupdate4 payload */)

				1 /* layoutupdate4 opaqueue len */)

				  /* the actual content of layoutupdate4 should

				     be allocated by drivers and spliced in

				     using xdr_write_pages */

#define decode_layoutcommit_maxsz (op_decode_hdr_maxsz + 3)

#define encode_layoutreturn_maxsz (8 + op_encode_hdr_maxsz + \

				encode_stateid_maxsz + \
@@ -1990,7 +1993,7 @@ encode_layoutget(struct xdr_stream *xdr, 
static int

encode_layoutcommit(struct xdr_stream *xdr,

		    struct inode *inode,

		    const struct nfs4_layoutcommit_args *args,

		    struct nfs4_layoutcommit_args *args,

		    struct compound_hdr *hdr)

{

	__be32 *p;
@@ -2011,11 +2014,16 @@ encode_layoutcommit(struct xdr_stream *xdr, 
	*p++ = cpu_to_be32(0); /* Never send time_modify_changed */

	*p++ = cpu_to_be32(NFS_SERVER(args->inode)->pnfs_curr_ld->id);/* type */



	if (NFS_SERVER(inode)->pnfs_curr_ld->encode_layoutcommit)

	if (NFS_SERVER(inode)->pnfs_curr_ld->encode_layoutcommit) {

		NFS_SERVER(inode)->pnfs_curr_ld->encode_layoutcommit(

			NFS_I(inode)->layout, xdr, args);

	else

		encode_uint32(xdr, 0); /* no layout-type payload */

	} else {

		encode_uint32(xdr, args->layoutupdate_len);

		if (args->layoutupdate_pages) {

			xdr_write_pages(xdr, args->layoutupdate_pages, 0,

					args->layoutupdate_len);

		}

	}



	return 0;

}

fs/nfs/pnfs.c

+15 −0
Original line number Diff line number Diff line
@@ -1854,6 +1854,7 @@ void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data) 
int

pnfs_layoutcommit_inode(struct inode *inode, bool sync)

{

	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;

	struct nfs4_layoutcommit_data *data;

	struct nfs_inode *nfsi = NFS_I(inode);

	loff_t end_pos;
@@ -1904,6 +1905,20 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync) 
	data->args.lastbytewritten = end_pos - 1;

	data->res.server = NFS_SERVER(inode);



	if (ld->prepare_layoutcommit) {

		status = ld->prepare_layoutcommit(&data->args);

		if (status) {

			spin_lock(&inode->i_lock);

			if (end_pos < nfsi->layout->plh_lwb)

				nfsi->layout->plh_lwb = end_pos;

			spin_unlock(&inode->i_lock);

			put_rpccred(data->cred);

			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);

			goto clear_layoutcommitting;

		}

	}





	status = nfs4_proc_layoutcommit(data, sync);

out:

	if (status)

fs/nfs/pnfs.h

+2 −2
Original line number Diff line number Diff line
@@ -128,8 +128,8 @@ struct pnfs_layoutdriver_type { 
				     const struct nfs4_layoutreturn_args *args);



	void (*cleanup_layoutcommit) (struct nfs4_layoutcommit_data *data);



	void (*encode_layoutcommit) (struct pnfs_layout_hdr *layoutid,

	int (*prepare_layoutcommit) (struct nfs4_layoutcommit_args *args);

	void (*encode_layoutcommit) (struct pnfs_layout_hdr *lo,

				     struct xdr_stream *xdr,

				     const struct nfs4_layoutcommit_args *args);

};

include/linux/nfs_xdr.h

+3 −0
Original line number Diff line number Diff line
@@ -279,6 +279,9 @@ struct nfs4_layoutcommit_args { 
	__u64 lastbytewritten;

	struct inode *inode;

	const u32 *bitmask;

	size_t layoutupdate_len;

	struct page *layoutupdate_page;

	struct page **layoutupdate_pages;

};



struct nfs4_layoutcommit_res {

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