Hi Fink On 06/13/2014 04:41 PM, Werner Fink wrote: > That is: set NOATIME, NOCOW, and NOCOMP for the journal directory > > --- > src/journal/journald-server.c | 29 +++++++++++++++++++++++++++-- > 1 file changed, 27 insertions(+), 2 deletions(-) > > diff --git src/journal/journald-server.c src/journal/journald-server.c > index eda5dcf..37d6dc3 100644 > --- src/journal/journald-server.c > +++ src/journal/journald-server.c > @@ -21,6 +21,7 @@ > > #include <sys/signalfd.h> > #include <sys/ioctl.h> > +#include <linux/fs.h> > #include <linux/sockios.h> > #include <sys/statvfs.h> > #include <sys/mman.h> > @@ -920,7 +921,7 @@ finish: > > > static int system_journal_open(Server *s) { > - int r; > + int r, fd; > char *fn; > sd_id128_t machine; > char ids[33]; > @@ -947,7 +948,31 @@ static int system_journal_open(Server *s) { > (void) mkdir("/var/log/journal/", 0755); > > fn = strappenda("/var/log/journal/", ids); > - (void) mkdir(fn, 0755); > + (void)mkdir(fn, 0755); > + > + /* > + * 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 one unkown flag (like BtrFS > does). > + */ > + if ((fd = open(fn, O_DIRECTORY)) >= 0) { > + long flags; > + if (ioctl(fd, FS_IOC_GETFLAGS, &flags) == 0) { > + int 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 I read correctly, you want set UN-conditionally the NOCOW behavior. Please, please, please DON'T DO that. The NOCOW behavior is not without disadvantage: yes it increase the performance but the file also lost the btrfs checksum protection; when BTRFS manage the disks in RAID mode and a corruption happens, it uses the checksum to select the correct mirror during the reading. If you set UN-conditionally the NOCOW behavior you lost this capability even if the user _want it_ (and if they spend moneys in two or more disks, it is likely they _want it_). Moreover the NOCOW flags has some "strange" behavior when a NOCOW file is snapshotted (it lost the NOCOW property); this may lead to irregular performance. If you want it, it must be configurable at least with a sane default (which IMHO should be "do nothing", following the "least surprise" rule). If you are looking to something like that, I suggest also to defrag the journal file before the open (but still as configurable option, and considering the "least surprise" rule). BR G.Baroncelli > + if (!(flags&FS_NOCOMP_FL) && s->compress) { > + flags &= ~FS_COMPR_FL; > + flags |= FS_NOCOMP_FL; > + } > + if (old != flags) > + ioctl(fd, FS_IOC_SETFLAGS, flags); > + } > + close(fd); > + } > > fn = strappenda(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); > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel