On Mon, Jan 6, 2020 at 3:42 PM Michael Paquier <mich...@paquier.xyz> wrote: > > On Mon, Jan 06, 2020 at 03:20:13PM +0900, Arthur Zakirov wrote: > > It isn't case if a file doesn't exist. But if there are no permissions on > > the file: > > > > PANIC: could not open file "testfile": Permissions denied > > server closed the connection unexpectedly > > > > It could be fixed by implementing a function like pg_file_sync_internal() or > > by making the function fsync_fname_ext() external. > > The patch uses stat() to make sure that the file exists and has no > issues. Though it could be a problem with any kind of TOCTOU-like > issues (looking at you, Windows, for ENOPERM), so I agree that it > would make more sense to use pg_fsync() here with a fd opened first.
I agree that it's not good for pg_file_sync() to cause a PANIC. I updated the patch so that pg_file_sync() uses fsync_fname_ext() instead of fsync_fname() as Arthur suggested. It's one of ideas to make pg_file_sync() open the file and directly call pg_fsync(). But fsync_fname_ext() has already such code and I'd like to avoid the code duplication. Attached is the updated version of the patch. Regards, -- Fujii Masao
pg_file_sync_v2.patch
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