6.8-stable review patch. If anyone has any objections, please let me know.
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From: Bernd Schubert bschubert@ddn.com
[ Upstream commit 9511176bbaee0ac60ecc84e7b01cf5972a59ea17 ]
There were multiple issues with direct_io_allow_mmap:
- fuse_link_write_file() was missing, resulting in warnings in fuse_write_file_get() and EIO from msync()
- "vma->vm_ops = &fuse_file_vm_ops" was not set, but especially fuse_page_mkwrite is needed.
The semantics of invalidate_inode_pages2() is so far not clearly defined in fuse_file_mmap. It dates back to commit 3121bfe76311 ("fuse: fix "direct_io" private mmap") Though, as direct_io_allow_mmap is a new feature, that was for MAP_PRIVATE only. As invalidate_inode_pages2() is calling into fuse_launder_folio() and writes out dirty pages, it should be safe to call invalidate_inode_pages2 for MAP_PRIVATE and MAP_SHARED as well.
Cc: Hao Xu howeyxu@tencent.com Cc: stable@vger.kernel.org Fixes: e78662e818f9 ("fuse: add a new fuse init flag to relax restrictions in no cache mode") Signed-off-by: Bernd Schubert bschubert@ddn.com Reviewed-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/fuse/file.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 148a71b8b4d0e..b9cff9b6ca1b8 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -2468,7 +2468,8 @@ static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) return fuse_dax_mmap(file, vma);
if (ff->open_flags & FOPEN_DIRECT_IO) { - /* Can't provide the coherency needed for MAP_SHARED + /* + * Can't provide the coherency needed for MAP_SHARED * if FUSE_DIRECT_IO_ALLOW_MMAP isn't set. */ if ((vma->vm_flags & VM_MAYSHARE) && !fc->direct_io_allow_mmap) @@ -2476,7 +2477,10 @@ static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
invalidate_inode_pages2(file->f_mapping);
- return generic_file_mmap(file, vma); + if (!(vma->vm_flags & VM_MAYSHARE)) { + /* MAP_PRIVATE */ + return generic_file_mmap(file, vma); + } }
if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))