Hi all, The following patchset adds support for tracking and clearing inodes with post-EOF space due to speculative preallocation. The purpose of this work is to add some flexibility and management control over inodes in this state. The specific impetus for this work is to support improved quota management in the glusterfs cluster filesystem. For example, this provides the ability to potentially free up a significant amount of unwritten space when at or near EDQUOT (FWIW, I'm also working on a patch to support prealloc throttling near EDQUOT, but I'm considering that separate). Despite the motivation, this work is intended to be generic and hopefully useful for other XFS users. We track inodes with post-EOF space via a new tag in the per-ag inode radix tree. The tag management, introduced in patch 1, is generally lazy in an attempt to keep things simple. Patch 2 implements scanning functionality to locate and potentially trim inodes with post-EOF space. Patch 3 adds a new ioctl() to extend support to userspace. Patch 4 adds background scanning based on the existing syncd workqueue. This patchset is marked RFC because aside from general review, I have some questions on the best approach for several bits (marked with 'TODO' comments), most notably whether we should include new tunables for the background scanning. Some further testing is warranted, but I suspect that using the syncd default of 30s might be a bit too aggressive for large files. These patches have been lightly unit tested and run through xfstests. Thoughts appreciated. Brian P.S., Credit to Dave Chinner for early review and guidance on design. Brian Foster (4): xfs: add EOFBLOCKS inode tagging/untagging xfs: create function to scan and clear EOFBLOCKS inodes xfs: add FREE_EOFBLOCKS ioctl xfs: add background scanning to clear EOFBLOCKS inodes fs/xfs/xfs_ag.h | 1 + fs/xfs/xfs_fs.h | 10 ++ fs/xfs/xfs_inode.h | 8 ++- fs/xfs/xfs_ioctl.c | 25 +++++ fs/xfs/xfs_iomap.c | 7 ++ fs/xfs/xfs_iops.c | 3 + fs/xfs/xfs_mount.h | 2 + fs/xfs/xfs_quota.h | 1 + fs/xfs/xfs_quotaops.c | 2 +- fs/xfs/xfs_sync.c | 277 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_sync.h | 9 ++ fs/xfs/xfs_trace.h | 5 + fs/xfs/xfs_vnodeops.c | 16 ++- fs/xfs/xfs_vnodeops.h | 2 + 14 files changed, 362 insertions(+), 6 deletions(-) -- 1.7.7.6 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
