[PATCH 4.9 195/240] NFSv4.2: Always flush out writes in nfs42_proc_fallocate()

Greg Kroah-Hartman
2021-05-20T11:21:11Z

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ Upstream commit 99f23783224355e7022ceea9b8d9f62c0fd01bd8 ]

Whether we're allocating or delallocating space, we should flush out the
pending writes in order to avoid races with attribute updates.

Fixes: 1e564d3dbd68 ("NFSv4.2: Fix a race in nfs42_proc_deallocate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/nfs42proc.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 5cda392028ce..7e9fb1119bcf 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -56,7 +56,8 @@ static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
loff_t offset, loff_t len)
{
- struct nfs_server *server = NFS_SERVER(file_inode(filep));
+ struct inode *inode = file_inode(filep);
+ struct nfs_server *server = NFS_SERVER(inode);
struct nfs4_exception exception = { };
struct nfs_lock_context *lock;
int err;
@@ -65,9 +66,13 @@ static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
if (IS_ERR(lock))
return PTR_ERR(lock);

- exception.inode = file_inode(filep);
+ exception.inode = inode;
exception.state = lock->open_context->state;

+ err = nfs_sync_inode(inode);
+ if (err)
+ goto out;
+
do {
err = _nfs42_proc_fallocate(msg, filep, lock, offset, len);
if (err == -ENOTSUPP) {
@@ -76,7 +81,7 @@ static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
}
err = nfs4_handle_exception(server, err, &exception);
} while (exception.retry);
-
+out:
nfs_put_lock_context(lock);
return err;
}
@@ -114,16 +119,13 @@ int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
return -EOPNOTSUPP;

inode_lock(inode);
- err = nfs_sync_inode(inode);
- if (err)
- goto out_unlock;

err = nfs42_proc_fallocate(&msg, filep, offset, len);
if (err == 0)
truncate_pagecache_range(inode, offset, (offset + len) -1);
if (err == -EOPNOTSUPP)
NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
-out_unlock:
+
inode_unlock(inode);
return err;
}
--
2.30.2