Messages in this thread Patch in this message | | | Date | Mon, 14 Aug 2023 14:07:08 +0200 | Subject | Re: [REGRESSION] fuse: execve() fails with ETXTBSY due to async fuse_flush | From | Bernd Schubert <> |
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On 8/14/23 13:02, Miklos Szeredi wrote: > On Mon, 14 Aug 2023 at 08:03, Jürg Billeter <j@bitron.ch> wrote: >> >> 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. > > Thanks for the report. > > At this point, I think it would be best to revert the original patch, > since only v6.4 has it. > > The original fix was already a workaround, and I don't see a clear > path forward in this direction. We need to see if there's better > direction. > > Ideas?
Is there a good reason to flush O_RDONLY?
fuse: Avoid flush for O_RDONLY
From: Bernd Schubert <bschubert@ddn.com>
A file opened in read-only moded does not have data to be flushed, so no need to send flush at all.
This also mitigates -EBUSY for executables, which is due to async flush with commit 5a8bee63b1.
Fixes: 5a8bee63b1 (unless executable opened in rw) Signed-off-by: Bernd Schubert <bschubert@ddn.com>
index 89d97f6188e0..e058a6af6751 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -545,7 +545,8 @@ static int fuse_flush(struct file *file, fl_owner_t id) if (fuse_is_bad(inode)) return -EIO; - if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache) + if ((ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache) || + ((file->f_flags & O_ACCMODE) == O_RDONLY)) return 0; fa = kzalloc(sizeof(*fa), GFP_KERNEL);
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