Commit 133a48ab authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Fix up commit deadlocks 



If O_DIRECT bumps the commit_info rpcs_out field, then that could lead
to fsync() hangs. The fix is to ensure that O_DIRECT calls
nfs_commit_end().

Fixes: 723c921e ("sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 64a93dbf

fs/nfs/direct.c

+1 −1
Original line number Diff line number Diff line
@@ -620,7 +620,7 @@ static void nfs_direct_commit_complete(struct nfs_commit_data *data) 
		nfs_unlock_and_release_request(req);

	}



	if (atomic_dec_and_test(&cinfo.mds->rpcs_out))

	if (nfs_commit_end(cinfo.mds))

		nfs_direct_write_complete(dreq);

}

fs/nfs/pnfs_nfs.c

+0 −2
Original line number Diff line number Diff line
@@ -468,7 +468,6 @@ pnfs_bucket_alloc_ds_commits(struct list_head *list, 
				goto out_error;

			data->ds_commit_index = i;

			list_add_tail(&data->list, list);

			atomic_inc(&cinfo->mds->rpcs_out);

			nreq++;

		}

		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
@@ -520,7 +519,6 @@ pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages, 
		data->ds_commit_index = -1;

		list_splice_init(mds_pages, &data->pages);

		list_add_tail(&data->list, &list);

		atomic_inc(&cinfo->mds->rpcs_out);

		nreq++;

	}

fs/nfs/write.c

+6 −3
Original line number Diff line number Diff line
@@ -1673,10 +1673,13 @@ static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo) 
	atomic_inc(&cinfo->rpcs_out);

}



static void nfs_commit_end(struct nfs_mds_commit_info *cinfo)

bool nfs_commit_end(struct nfs_mds_commit_info *cinfo)

{

	if (atomic_dec_and_test(&cinfo->rpcs_out))

	if (atomic_dec_and_test(&cinfo->rpcs_out)) {

		wake_up_var(&cinfo->rpcs_out);

		return true;

	}

	return false;

}



void nfs_commitdata_release(struct nfs_commit_data *data)
@@ -1776,6 +1779,7 @@ void nfs_init_commit(struct nfs_commit_data *data, 
	data->res.fattr   = &data->fattr;

	data->res.verf    = &data->verf;

	nfs_fattr_init(&data->fattr);

	nfs_commit_begin(cinfo->mds);

}

EXPORT_SYMBOL_GPL(nfs_init_commit);
@@ -1822,7 +1826,6 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how, 


	/* Set up the argument struct */

	nfs_init_commit(data, head, NULL, cinfo);

	atomic_inc(&cinfo->mds->rpcs_out);

	if (NFS_SERVER(inode)->nfs_client->cl_minorversion)

		task_flags = RPC_TASK_MOVEABLE;

	return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),

include/linux/nfs_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -568,6 +568,7 @@ extern int nfs_wb_page_cancel(struct inode *inode, struct page* page); 
extern int  nfs_commit_inode(struct inode *, int);

extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail);

extern void nfs_commit_free(struct nfs_commit_data *data);

bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);



static inline int

nfs_have_writebacks(struct inode *inode)