Horton

Make safeguard against incorrect flags for fsync more portable.

Tom Lane <tgl@sss.pgh.pa.us>

View on postgr.es
Commit: 71d71ac4d1bbb34a9814f010812e059c29c9472e
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2025-07-01T16:08:57Z
Releases: 14.19 
Make safeguard against incorrect flags for fsync more portable.

The existing code assumed that O_RDONLY is defined as 0, but this is
not required by POSIX and is not true on GNU Hurd.  We can avoid
the assumption by relying on O_ACCMODE to mask the fcntl() result.
(Hopefully, all supported platforms define that.)

Author: Michael Banck <mbanck@gmx.net>
Co-authored-by: Samuel Thibault
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/6862e8d1.050a0220.194b8d.76fa@mx.google.com
Discussion: https://postgr.es/m/68480868.5d0a0220.1e214d.68a6@mx.google.com
Backpatch-through: 13

Files

PathChange+/−
src/backend/storage/file/fd.c modified +8 −11

Discussion