Horton

Make safeguard against incorrect flags for fsync more portable.

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

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Commit: 3a2617e4f0be734f58f7219986c323469b502921
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2025-07-01T16:08:20Z
Releases: 16.10 
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

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