Commit 3634a632 authored by Brian Foster's avatar Brian Foster Committed by Miklos Szeredi
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fuse: truncate pagecache range on hole punch

fuse supports hole punch via the fallocate() FALLOC_FL_PUNCH_HOLE
interface. When a hole punch is passed through, the page cache
is not cleared and thus allows reading stale data from the cache.

This is easily demonstrable (using FOPEN_KEEP_CACHE) by reading a
smallish random data file into cache, punching a hole and creating
a copy of the file. Drop caches or remount and observe that the
original file no longer matches the file copied after the hole
punch. The original file contains a zeroed range and the latter
file contains stale data.

Protect against writepage requests in progress and punch out the
associated page cache range after a successful client fs hole
Signed-off-by: default avatarBrian Foster <>
Signed-off-by: default avatarMiklos Szeredi <>
parent de82b923
......@@ -16,6 +16,7 @@
#include <linux/compat.h>
#include <linux/swap.h>
#include <linux/aio.h>
#include <linux/falloc.h>
static const struct file_operations fuse_direct_io_file_operations;
......@@ -2453,6 +2454,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
loff_t length)
struct fuse_file *ff = file->private_data;
struct inode *inode = file->f_inode;
struct fuse_conn *fc = ff->fc;
struct fuse_req *req;
struct fuse_fallocate_in inarg = {
......@@ -2466,9 +2468,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
if (fc->no_fallocate)
if (mode & FALLOC_FL_PUNCH_HOLE) {
req = fuse_get_req_nopages(fc);
if (IS_ERR(req))
return PTR_ERR(req);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
req->in.h.opcode = FUSE_FALLOCATE;
req->in.h.nodeid = ff->nodeid;
......@@ -2483,6 +2492,15 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
fuse_put_request(fc, req);
if (mode & FALLOC_FL_PUNCH_HOLE) {
if (!err)
truncate_pagecache_range(inode, offset,
offset + length - 1);
return err;
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