On Thu, Jan 9, 2020 at 10:39 PM Julien Rouhaud <rjuju...@gmail.com> wrote: > > On Thu, Jan 9, 2020 at 7:31 AM Fujii Masao <masao.fu...@gmail.com> wrote: > > > > 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. > > This looks good to me. > > > Attached is the updated version of the patch. > > + <row> > + <entry><function>pg_catalog.pg_file_sync(filename > text)</function></entry> > + <entry><type>boolean</type></entry> > + <entry> > + Sync a file or directory > + </entry> > + </row> > > "Flush to disk" looks better than "sync" here.
I changed the doc that way. Thanks for the review! > I think that pg_write_server_files should be allowed to call that > function by default. But pg_write_server_files users are not allowed to execute other functions like pg_file_write() by default. So doing that change only for pg_file_sync() looks strange to me. Regards, -- Fujii Masao
pg_file_sync_v3.patch
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