Revert "fuse: in fuse_flush only wait if someone wants the return code"

commit 91ec6c8559 upstream.

This reverts commit 5a8bee63b1.

Jürg Billeter reports the following regression:

  Since v6.3-rc1 commit 5a8bee63b1 ("fuse: in fuse_flush only wait if
  someone wants the return code") `fput()` is called asynchronously if a
  file is closed as part of a process exiting, i.e., if there was no
  explicit `close()` before exit.

  If the file was open for writing, also `put_write_access()` is called
  asynchronously as part of the async `fput()`.

  If that newly written file is an executable, attempting to `execve()` the
  new file can fail with `ETXTBSY` if it's called after the writer process
  exited but before the async `fput()` has run.

Reported-and-tested-by: "Jürg Billeter" <j@bitron.ch>
Cc: <stable@vger.kernel.org> # v6.3
Link: https://lore.kernel.org/all/4f66cded234462964899f2a661750d6798a57ec0.camel@bitron.ch/
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Miklos Szeredi 2023-08-14 13:05:30 +02:00 committed by Greg Kroah-Hartman
parent f48c2c758e
commit ec3c547fba

View File

@ -19,7 +19,6 @@
#include <linux/uio.h>
#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/file.h>
static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
unsigned int open_flags, int opcode,
@ -479,36 +478,48 @@ static void fuse_sync_writes(struct inode *inode)
fuse_release_nowrite(inode);
}
struct fuse_flush_args {
struct fuse_args args;
struct fuse_flush_in inarg;
struct work_struct work;
struct file *file;
};
static int fuse_do_flush(struct fuse_flush_args *fa)
static int fuse_flush(struct file *file, fl_owner_t id)
{
int err;
struct inode *inode = file_inode(fa->file);
struct inode *inode = file_inode(file);
struct fuse_mount *fm = get_fuse_mount(inode);
struct fuse_file *ff = file->private_data;
struct fuse_flush_in inarg;
FUSE_ARGS(args);
int err;
if (fuse_is_bad(inode))
return -EIO;
if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
return 0;
err = write_inode_now(inode, 1);
if (err)
goto out;
return err;
inode_lock(inode);
fuse_sync_writes(inode);
inode_unlock(inode);
err = filemap_check_errors(fa->file->f_mapping);
err = filemap_check_errors(file->f_mapping);
if (err)
goto out;
return err;
err = 0;
if (fm->fc->no_flush)
goto inval_attr_out;
err = fuse_simple_request(fm, &fa->args);
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
args.opcode = FUSE_FLUSH;
args.nodeid = get_node_id(inode);
args.in_numargs = 1;
args.in_args[0].size = sizeof(inarg);
args.in_args[0].value = &inarg;
args.force = true;
err = fuse_simple_request(fm, &args);
if (err == -ENOSYS) {
fm->fc->no_flush = 1;
err = 0;
@ -521,57 +532,9 @@ inval_attr_out:
*/
if (!err && fm->fc->writeback_cache)
fuse_invalidate_attr_mask(inode, STATX_BLOCKS);
out:
fput(fa->file);
kfree(fa);
return err;
}
static void fuse_flush_async(struct work_struct *work)
{
struct fuse_flush_args *fa = container_of(work, typeof(*fa), work);
fuse_do_flush(fa);
}
static int fuse_flush(struct file *file, fl_owner_t id)
{
struct fuse_flush_args *fa;
struct inode *inode = file_inode(file);
struct fuse_mount *fm = get_fuse_mount(inode);
struct fuse_file *ff = file->private_data;
if (fuse_is_bad(inode))
return -EIO;
if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
return 0;
fa = kzalloc(sizeof(*fa), GFP_KERNEL);
if (!fa)
return -ENOMEM;
fa->inarg.fh = ff->fh;
fa->inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
fa->args.opcode = FUSE_FLUSH;
fa->args.nodeid = get_node_id(inode);
fa->args.in_numargs = 1;
fa->args.in_args[0].size = sizeof(fa->inarg);
fa->args.in_args[0].value = &fa->inarg;
fa->args.force = true;
fa->file = get_file(file);
/* Don't wait if the task is exiting */
if (current->flags & PF_EXITING) {
INIT_WORK(&fa->work, fuse_flush_async);
schedule_work(&fa->work);
return 0;
}
return fuse_do_flush(fa);
}
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
int datasync, int opcode)
{