[PATCH 4.19 21/44] fuse: continue to send FUSE_RELEASEDIR when FUSE_OPEN returns ENOSYS

Greg Kroah-Hartman
2018-12-18T16:44:05Z

From: Chad Austin <chadaustin@fb.com>

commit 2e64ff154ce6ce9a8dc0f9556463916efa6ff460 upstream.

When FUSE_OPEN returns ENOSYS, the no_open bit is set on the connection.

Because the FUSE_RELEASE and FUSE_RELEASEDIR paths share code, this
incorrectly caused the FUSE_RELEASEDIR request to be dropped and never sent
to userspace.

Pass an isdir bool to distinguish between FUSE_RELEASE and FUSE_RELEASEDIR
inside of fuse_file_put.

Fixes: 7678ac50615d ("fuse: support clients that don't implement 'open'")
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/fuse/dir.c | 2 +-
fs/fuse/file.c | 21 +++++++++++----------
fs/fuse/fuse_i.h | 2 +-
3 files changed, 13 insertions(+), 12 deletions(-)

--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1439,7 +1439,7 @@ static int fuse_dir_open(struct inode *i

static int fuse_dir_release(struct inode *inode, struct file *file)
{
- fuse_release_common(file, FUSE_RELEASEDIR);
+ fuse_release_common(file, true);

return 0;
}
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -87,12 +87,12 @@ static void fuse_release_end(struct fuse
iput(req->misc.release.inode);
}

-static void fuse_file_put(struct fuse_file *ff, bool sync)
+static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
{
if (refcount_dec_and_test(&ff->count)) {
struct fuse_req *req = ff->reserved_req;

- if (ff->fc->no_open) {
+ if (ff->fc->no_open && !isdir) {
/*
* Drop the release request when client does not
* implement 'open'
@@ -245,10 +245,11 @@ static void fuse_prepare_release(struct
req->in.args[0].value = inarg;
}

-void fuse_release_common(struct file *file, int opcode)
+void fuse_release_common(struct file *file, bool isdir)
{
struct fuse_file *ff = file->private_data;
struct fuse_req *req = ff->reserved_req;
+ int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;

fuse_prepare_release(ff, file->f_flags, opcode);

@@ -270,7 +271,7 @@ void fuse_release_common(struct file *fi
* synchronous RELEASE is allowed (and desirable) in this case
* because the server can be trusted not to screw up.
*/
- fuse_file_put(ff, ff->fc->destroy_req != NULL);
+ fuse_file_put(ff, ff->fc->destroy_req != NULL, isdir);
}

static int fuse_open(struct inode *inode, struct file *file)
@@ -286,7 +287,7 @@ static int fuse_release(struct inode *in
if (fc->writeback_cache)
write_inode_now(inode, 1);

- fuse_release_common(file, FUSE_RELEASE);
+ fuse_release_common(file, false);

/* return value is ignored by VFS */
return 0;
@@ -300,7 +301,7 @@ void fuse_sync_release(struct fuse_file
* iput(NULL) is a no-op and since the refcount is 1 and everything's
* synchronous, we are fine with not doing igrab() here"
*/
- fuse_file_put(ff, true);
+ fuse_file_put(ff, true, false);
}
EXPORT_SYMBOL_GPL(fuse_sync_release);

@@ -805,7 +806,7 @@ static void fuse_readpages_end(struct fu
put_page(page);
}
if (req->ff)
- fuse_file_put(req->ff, false);
+ fuse_file_put(req->ff, false, false);
}

static void fuse_send_readpages(struct fuse_req *req, struct file *file)
@@ -1459,7 +1460,7 @@ static void fuse_writepage_free(struct f
__free_page(req->pages[i]);

if (req->ff)
- fuse_file_put(req->ff, false);
+ fuse_file_put(req->ff, false, false);
}

static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
@@ -1616,7 +1617,7 @@ int fuse_write_inode(struct inode *inode
ff = __fuse_write_file_get(fc, fi);
err = fuse_flush_times(inode, ff);
if (ff)
- fuse_file_put(ff, 0);
+ fuse_file_put(ff, false, false);

return err;
}
@@ -1930,7 +1931,7 @@ static int fuse_writepages(struct addres
err = 0;
}
if (data.ff)
- fuse_file_put(data.ff, false);
+ fuse_file_put(data.ff, false, false);

kfree(data.orig_pages);
out:
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -749,7 +749,7 @@ void fuse_sync_release(struct fuse_file
/**
* Send RELEASE or RELEASEDIR request
*/
-void fuse_release_common(struct file *file, int opcode);
+void fuse_release_common(struct file *file, bool isdir);

/**
* Send FSYNC or FSYNCDIR request