From 3010fb0e069d2fd4c7a6ade4559bfb659bf8f2fb Mon Sep 17 00:00:00 2001 From: Julian Andres Klode Date: Tue, 29 Jun 2010 17:23:24 +0200 Subject: * apt-pkg/contrib/fileutl.cc: - Make FileFd replace files atomically in WriteTemp mode (for cache, etc). --- apt-pkg/contrib/fileutl.cc | 20 +++++++++++++++----- apt-pkg/contrib/fileutl.h | 3 ++- 2 files changed, 17 insertions(+), 6 deletions(-) (limited to 'apt-pkg/contrib') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index 16f7ce929..0b0739cda 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -27,6 +27,7 @@ #include #include +#include #include #include @@ -654,10 +655,11 @@ bool FileFd::Open(string FileName,OpenMode Mode, unsigned long Perms) case WriteEmpty: { - struct stat Buf; - if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode)) - unlink(FileName.c_str()); - iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_TRUNC,Perms); + Flags |= Replace; + char *name = strdup((FileName + ".XXXXXX").c_str()); + TemporaryFileName = string(mktemp(name)); + iFd = open(TemporaryFileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms); + free(name); break; } @@ -839,11 +841,19 @@ bool FileFd::Close() if (iFd >= 0 && close(iFd) != 0) Res &= _error->Errno("close",_("Problem closing the file")); iFd = -1; - + + if ((Flags & Replace) == Replace) { + FileName = TemporaryFileName; // for the unlink() below. + if (rename(TemporaryFileName.c_str(), FileName.c_str()) != 0) + Res &= _error->Errno("rename",_("Problem renaming the file")); + } + if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail && FileName.empty() == false) if (unlink(FileName.c_str()) != 0) Res &= _error->WarningE("unlnk",_("Problem unlinking the file")); + + return Res; } /*}}}*/ diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h index 003bd9b83..528725f89 100644 --- a/apt-pkg/contrib/fileutl.h +++ b/apt-pkg/contrib/fileutl.h @@ -34,9 +34,10 @@ class FileFd int iFd; enum LocalFlags {AutoClose = (1<<0),Fail = (1<<1),DelOnFail = (1<<2), - HitEof = (1<<3)}; + HitEof = (1<<3), Replace = (1<<4) }; unsigned long Flags; string FileName; + string TemporaryFileName; public: enum OpenMode {ReadOnly,WriteEmpty,WriteExists,WriteAny,WriteTemp}; -- cgit v1.2.3 From fd3b761e8cba6ed626639b50b1221246098c7b3a Mon Sep 17 00:00:00 2001 From: Julian Andres Klode Date: Tue, 29 Jun 2010 17:28:33 +0200 Subject: Fix the atomic replace. --- apt-pkg/contrib/fileutl.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'apt-pkg/contrib') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index 0b0739cda..0b62d1bd8 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -843,9 +843,9 @@ bool FileFd::Close() iFd = -1; if ((Flags & Replace) == Replace) { - FileName = TemporaryFileName; // for the unlink() below. if (rename(TemporaryFileName.c_str(), FileName.c_str()) != 0) Res &= _error->Errno("rename",_("Problem renaming the file")); + FileName = TemporaryFileName; // for the unlink() below. } if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail && -- cgit v1.2.3