From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 133a48abf6ecc535d7eddc6da1c3e4c972445882 ]
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: 723c921e7dfc ("sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/direct.c | 2 +- fs/nfs/pnfs_nfs.c | 2 -- fs/nfs/write.c | 9 ++++++--- include/linux/nfs_fs.h | 1 + 4 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 2e894fec036b0..3c0335c15a730 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -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); }
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index 02bd6e83961d9..316f68f96e573 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -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++; }
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 735a054747752..7dce3e735fc53 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1657,10 +1657,13 @@ 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) @@ -1760,6 +1763,7 @@ 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);
@@ -1806,7 +1810,6 @@ 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), diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index ce64745948722..36405ce03b1dc 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -564,6 +564,7 @@ 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)