From 79897201751cdc9e5c6194a096f8506ef8d8b5ac Mon Sep 17 00:00:00 2001 From: =?utf8?q?P=C3=A1draig=20Brady?= Date: Wed, 6 May 2015 16:23:56 +0100 Subject: [PATCH] doc: document glibc posix_fallocate() issues * doc/posix-functions/posix_fallocate.texi: Mention the glibc efficiency problems and issues with NFS. --- ChangeLog | 6 ++++++ doc/posix-functions/posix_fallocate.texi | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/ChangeLog b/ChangeLog index cf3acc7ee1..fc08ebae5c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2015-05-06 Pádraig Brady + + doc: document glibc posix_fallocate() issues + * doc/posix-functions/posix_fallocate.texi: Mention the + glibc efficiency problems and issues with NFS. + 2015-05-05 Karl Berry * build-aux/gendocs.sh (usage): document new css default diff --git a/doc/posix-functions/posix_fallocate.texi b/doc/posix-functions/posix_fallocate.texi index a7c47008d8..9e04b44e22 100644 --- a/doc/posix-functions/posix_fallocate.texi +++ b/doc/posix-functions/posix_fallocate.texi @@ -17,6 +17,12 @@ This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS. @item +POSIX specifies that EINVAL should be returned when the file system doesn't +support the allocation operation directly. glibc however emulates the file system +allocation with writes where unsupported, and apps have depended on +that long term implementation. This is both inefficient, and as of +glibc 2.21 at least, buggy on certain NFS setups. +@item On platforms where @code{off_t} is a 32-bit type, this function may not work correctly across the entire data range of files larger than 2 GB. The fix is to use the @code{AC_SYS_LARGEFILE} macro. -- 2.39.5