5.4-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trond.myklebust@hammerspace.com
commit 133a48abf6ecc535d7eddc6da1c3e4c972445882 upstream.
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: Chanho Min chanho.min@lge.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/direct.c | 2 +- fs/nfs/write.c | 9 ++++++--- include/linux/nfs_fs.h | 1 + 3 files changed, 8 insertions(+), 4 deletions(-)
--- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -700,7 +700,7 @@ static void nfs_direct_commit_complete(s 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); }
--- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1658,10 +1658,13 @@ static void nfs_commit_begin(struct nfs_ 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) @@ -1756,6 +1759,7 @@ void nfs_init_commit(struct nfs_commit_d 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);
@@ -1801,7 +1805,6 @@ nfs_commit_list(struct inode *inode, str
/* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); - atomic_inc(&cinfo->mds->rpcs_out); return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), data->mds_ops, how, 0); } --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -549,6 +549,7 @@ extern int nfs_wb_page_cancel(struct ino 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)