From: werner@suse.de Upstream: marked as openSUSE-specific fix originally, but may well worth be to be sent upstream. Original description: (none) Augmented description [jengelh@inai.de]: Disable COW on journal files, as that is naturally leading to a lot of unwanted fragmentation on btrfs. No word on compression… --- src/journal/journald-server.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) Index: systemd-227/src/journal/journald-server.c =================================================================== --- systemd-227.orig/src/journal/journald-server.c +++ systemd-227/src/journal/journald-server.c @@ -24,6 +24,7 @@ #include #endif #include +#include #include #include #include @@ -861,6 +862,39 @@ void server_driver_message(Server *s, sd dispatch_message_real(s, iovec, n, ELEMENTSOF(iovec), &ucred, NULL, NULL, 0, NULL, LOG_INFO, 0); } +/* + * On journaling and/or compressing file systems, avoid doubling the efforts + * for the system, that is, set NOCOW and NOCOMP inode flags. Check for every + * single flag, as otherwise, some of the file systems may return EOPNOTSUPP on + * a single unkown flag (like Btrfs does). + * + * …but src/journal/journal-file.c already sets NOCOW too…⸘ + */ +static void disable_cow(const char *dir, const Server *serv) +{ + unsigned long flags; + int fd = open(dir, O_DIRECTORY); + + if (fd < 0) + return; + if (ioctl(fd, FS_IOC_GETFLAGS, &flags) == 0) { + unsigned long old = flags; + if (!(flags & FS_NOATIME_FL) && + ioctl(fd, FS_IOC_SETFLAGS, flags | FS_NOATIME_FL) == 0) + flags |= FS_NOATIME_FL; + if (!(flags & FS_NOCOW_FL) && + ioctl(fd, FS_IOC_SETFLAGS, flags | FS_NOCOW_FL) == 0) + flags |= FS_NOCOW_FL; + if (!(flags & FS_NOCOMP_FL) && serv->compress) { + flags &= ~FS_COMPR_FL; + flags |= FS_NOCOMP_FL; + } + if (old != flags) + ioctl(fd, FS_IOC_SETFLAGS, flags); + } + close(fd); +} + void server_dispatch_message( Server *s, struct iovec *iovec, unsigned n, unsigned m, @@ -948,6 +982,7 @@ static int system_journal_open(Server *s fn = strjoina("/var/log/journal/", SERVER_MACHINE_ID(s)); (void) mkdir(fn, 0755); + disable_cow(fn, s); fn = strjoina(fn, "/system.journal"); r = journal_file_open_reliably(fn, O_RDWR|O_CREAT, 0640, s->compress, s->seal, &s->system_metrics, s->mmap, NULL, &s->system_journal);