This is v3 of the speculative preallocation inode tracking patchset. This
functionality tracks inodes with post-EOF speculative preallocation for the
purpose of background and on-demand trimming.
Background scanning occurs on a longish interval (5 minutes by default) and in
a best-effort mode (i.e., inodes are skipped due to lock contention or dirty
cache). The intent is to clear up post-EOF blocks on inodes that might have
allocations hanging around due to open-write-close sequences (NFS).
On demand scanning is provided via a new ioctl and supports various parameters
such as scan mode, filtering by quota id and minimum file size. A pending use
case for on demand scanning is for accurate quota accounting via the gluster
scale out filesystem (i.e., to free up preallocated space when near a usage
P.S., I've rebased and run this through xfstests a couple times. I'll probably
run at least once more with a low background scan interval just for sanity sake.
Also, Dave previously mentioned this conflicts with the xfssyncd patchset. I can
rebase on top of that if there is any preference in terms of order.
- Pushed dirty cache check up into patch 5 (minor clean up).
- Reworked xfs_can_free_eofblocks() in patch 3 as per Dave C.'s review.
- Rebased from linus' tree to the XFS tree.
- Remove unnecessary inode flag clear helper.
- Condense eofblocks set/clear tag functions.
- Move clear tag call into xfs_free_eofblocks().
- Modify AG walk infrastructure to support tag-based walk and utilize this
functionality for the eofblocks scan (as opposed to the previous code
duplicated from reclaim scanning).
- Improve ioctl functionality: new data structure fields/flags, validate quota
- Increase default background scanning interval to 5 minutes, add tunable.
Brian Foster (8):
xfs: add EOFBLOCKS inode tagging/untagging
xfs: support a tag-based inode_ag_iterator
xfs: create helper to check whether to free eofblocks on inode
xfs: export xfs_free_eofblocks() and return EAGAIN on trylock failure
xfs: create function to scan and clear EOFBLOCKS inodes
xfs: add XFS_IOC_FREE_EOFBLOCKS ioctl
xfs: add enhanced filtering to EOFBLOCKS scan
xfs: add background scanning to clear EOFBLOCKS inodes
fs/xfs/xfs_ag.h | 1 +
fs/xfs/xfs_fs.h | 23 +++++
fs/xfs/xfs_globals.c | 1 +
fs/xfs/xfs_ioctl.c | 20 ++++
fs/xfs/xfs_iomap.c | 7 ++
fs/xfs/xfs_iops.c | 3 +
fs/xfs/xfs_linux.h | 1 +
fs/xfs/xfs_mount.h | 2 +
fs/xfs/xfs_qm_syscalls.c | 5 +-
fs/xfs/xfs_sync.c | 215 ++++++++++++++++++++++++++++++++++++++++++++--
fs/xfs/xfs_sync.h | 11 ++-
fs/xfs/xfs_sysctl.c | 9 ++
fs/xfs/xfs_sysctl.h | 1 +
fs/xfs/xfs_trace.h | 6 ++
fs/xfs/xfs_vnodeops.c | 27 +++---
fs/xfs/xfs_vnodeops.h | 41 +++++++++-
16 files changed, 344 insertions(+), 29 deletions(-)