From: Linus Torvalds Date: Sat, 6 Aug 2016 13:50:36 +0000 (-0400) Subject: Merge tag 'xfs-rmap-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel... X-Git-Tag: v4.8-rc1~7 X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=0cbbc422d56668528f6efd1234fe908010284082 Merge tag 'xfs-rmap-for-linus-4.8-rc1' of git://git./linux/kernel/git/dgc/linux-xfs Pull more xfs updates from Dave Chinner: "This is the second part of the XFS updates for this merge cycle, and contains the new reverse block mapping feature for XFS. Reverse mapping allows us to track the owner of a specific block on disk precisely. It is implemented as a set of btrees (one per allocation group) that track the owners of allocated extents. Effectively it is a "used space tree" that is updated when we allocate or free extents. i.e. it is coherent with the free space btrees we already maintain and never overlaps with them. This reverse mapping infrastructure is the building block of several upcoming features - reflink, copy-on-write data, dedupe, online metadata and data scrubbing, highly accurate bad sector/data loss reporting to users, and significantly improved reconstruction of damaged and corrupted filesystems. There's a lot of new stuff coming along in the next couple of cycles,a nd it all builds in the rmap infrastructure. As such, it's a huge chunk of new code with new on-disk format features and internal infrastructure. It warns at mount time as an experimental feature and that it may eat data (as we do with all new on-disk features until they stabilise). We have not released userspace suport for it yet - userspace support currently requires download from Darrick's xfsprogs repo and build from source, so the access to this feature is really developer/tester only at this point. Initial userspace support will be released at the same time kernel with this code in it is released. The new rmap enabled code regresses 3 xfstests - all are ENOSPC related corner cases, one of which Darrick posted a fix for a few hours ago. The other two are fixed by infrastructure that is part of the upcoming reflink patchset. This new ENOSPC infrastructure requires a on-disk format tweak required to keep mount times in check - we need to keep an on-disk count of allocated rmapbt blocks so we don't have to scan the entire btrees at mount time to count them. This is currently being tested and will be part of the fixes sent in the next week or two so users will not be exposed to this change" * tag 'xfs-rmap-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (52 commits) xfs: move (and rename) the deferred bmap-free tracepoints xfs: collapse single use static functions xfs: remove unnecessary parentheses from log redo item recovery functions xfs: remove the extents array from the rmap update done log item xfs: in btree_lshift, only allocate temporary cursor when needed xfs: remove unnecesary lshift/rshift key initialization xfs: remove the get*keys and update_keys btree ops pointers xfs: enable the rmap btree functionality xfs: don't update rmapbt when fixing agfl xfs: disable XFS_IOC_SWAPEXT when rmap btree is enabled xfs: add rmap btree block detection to log recovery xfs: add rmap btree geometry feature flag xfs: propagate bmap updates to rmapbt xfs: enable the xfs_defer mechanism to process rmaps to update xfs: log rmap intent items xfs: create rmap update intent log items xfs: add rmap btree insert and delete helpers xfs: convert unwritten status of reverse mappings xfs: remove an extent from the rmap btree xfs: add an extent to the rmap btree ... --- 0cbbc422d56668528f6efd1234fe908010284082