| Message ID | cover.1721066206.git.dsterba@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [GIT,PULL] Btrfs updates for 6.11 | expand |
The pull request you sent on Mon, 15 Jul 2024 20:12:20 +0200:
> git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git tags/for-6.11-tag
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/a1b547f0f217cfb06af7eb4ce8488b02d83a0370
Thank you!
On Mon, 15 Jul 2024 at 11:12, David Sterba <dsterba@suse.com> wrote: > > There's a merge conflict caused by the latency fixes from last week in > extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 > and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's > been in linux-next for a few days. Oh, and I notice that my resolution is slightly different, but looks like the actual code is equivalent. I kept the "q" logic that had been introduced by commit 4e660ca3a98d ("btrfs: use a regular rb_root instead of cached rb_root for extent_map_tree"). I don't know how you prefer the code, but it kept the two "while (node)" loops in that file looking similar. Of course, they were very different in other respects (ie drop_all_extent_maps_fast() does all extents unconditionally with that retry logic, while btrfs_scan_inode() has that whole "bail out on any contention" model, so whatever. Anyway, it all *looks* ok to me, but please go and double-check that I didn't mess something up. Linus
On Wed, Jul 17, 2024 at 01:21:17PM -0700, Linus Torvalds wrote: > On Mon, 15 Jul 2024 at 11:12, David Sterba <dsterba@suse.com> wrote: > > > > There's a merge conflict caused by the latency fixes from last week in > > extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 > > and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's > > been in linux-next for a few days. > > Oh, and I notice that my resolution is slightly different, but looks > like the actual code is equivalent. > > I kept the "q" logic that had been introduced by commit 4e660ca3a98d > ("btrfs: use a regular rb_root instead of cached rb_root for > extent_map_tree"). > > I don't know how you prefer the code, but it kept the two "while > (node)" loops in that file looking similar. That is fine, keeping the same style makes sense. > Of course, they were very different in other respects (ie > drop_all_extent_maps_fast() does all extents unconditionally with that > retry logic, while btrfs_scan_inode() has that whole "bail out on any > contention" model, so whatever. > > Anyway, it all *looks* ok to me, but please go and double-check that I > didn't mess something up. Looks correct to me as well.
On Mon, Jul 15, 2024 at 8:12 PM David Sterba <dsterba@suse.com> wrote: > please pull the changes described below. The hilights are new logic > behind background block group reclaim, automatic removal of qgroup > after removing a subvolume and new 'rescue=' mount options. The rest is > optimizations, cleanups and refactoring. > > There's a merge conflict caused by the latency fixes from last week in > extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 > and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's > been in linux-next for a few days. FTR, this is broken on 32-bit (doesn't build, good ;-) and on big-endian (compiler warnings, no idea how it behaves :-(, so you better don't trust your data to it in the latter case... Gr{oetje,eeting}s, Geert
Hi David, On Fri, Jul 19, 2024 at 1:25 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > On Mon, Jul 15, 2024 at 8:12 PM David Sterba <dsterba@suse.com> wrote: > > please pull the changes described below. The hilights are new logic > > behind background block group reclaim, automatic removal of qgroup > > after removing a subvolume and new 'rescue=' mount options. The rest is > > optimizations, cleanups and refactoring. > > > > There's a merge conflict caused by the latency fixes from last week in > > extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 > > and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's > > been in linux-next for a few days. > > FTR, this is broken on 32-bit (doesn't build, good ;-) and on big-endian > (compiler warnings, no idea how it behaves :-(, so you better don't > trust your data to it in the latter case... I cannot find any other report of this, and don't know yet where it was introduced, but the bots started reporting this last May: 3 fs/btrfs/inode.c:5711:5: warning: ‘location.type’ may be used uninitialized in this function [-Wmaybe-uninitialized] 3 fs/btrfs/inode.c:5640:9: warning: ‘location.objectid’ may be used uninitialized in this function [-Wmaybe-uninitialized] https://lore.kernel.org/all/6655b55f.170a0220.406f9.2e0e@mx.google.com/ and I'm seeing failures in e.g. my m68k allmodconfig builds with gcc 9.5 due to CONFIG_WERROR=y. I suspect the big-endian accessors in fs/btrfs/accessors.h lack some initializations? Gr{oetje,eeting}s, Geert
On Fri, Jul 19, 2024 at 01:35:53PM +0200, Geert Uytterhoeven wrote: > Hi David, > > On Fri, Jul 19, 2024 at 1:25 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote: > > On Mon, Jul 15, 2024 at 8:12 PM David Sterba <dsterba@suse.com> wrote: > > > please pull the changes described below. The hilights are new logic > > > behind background block group reclaim, automatic removal of qgroup > > > after removing a subvolume and new 'rescue=' mount options. The rest is > > > optimizations, cleanups and refactoring. > > > > > > There's a merge conflict caused by the latency fixes from last week in > > > extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 > > > and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's > > > been in linux-next for a few days. > > > > FTR, this is broken on 32-bit (doesn't build, good ;-) and on big-endian > > (compiler warnings, no idea how it behaves :-(, so you better don't > > trust your data to it in the latter case... Internet forums are full of such quick and wrong conclusions, you don't need to write more. > I cannot find any other report of this, and don't know yet where it > was introduced, but the bots started reporting this last May: > > 3 fs/btrfs/inode.c:5711:5: warning: ‘location.type’ may be used > uninitialized in this function [-Wmaybe-uninitialized] > 3 fs/btrfs/inode.c:5640:9: warning: ‘location.objectid’ may be > used uninitialized in this function [-Wmaybe-uninitialized] > > https://lore.kernel.org/all/6655b55f.170a0220.406f9.2e0e@mx.google.com/ > > and I'm seeing failures in e.g. my m68k allmodconfig builds with > gcc 9.5 due to CONFIG_WERROR=y. Older compilers like 9.5 could not be able to reason about variable validity in case it's passed by address, as is in this case: 5707 ret = btrfs_inode_by_name(BTRFS_I(dir), dentry, &location, &di_type); 5708 if (ret < 0) 5709 return ERR_PTR(ret); and btrfs_inode_by_name() returns either a valid 'location' or an error that the caller handles and does not use the variable. > I suspect the big-endian accessors in fs/btrfs/accessors.h lack some > initializations? There are no special accessors on big endian hosts, same code, same bytes in memory only a different order. We fix warnings caused -Wmaybe-uninitialized even if it's because of old compilers, but it's hard to notice reports if they're burried in some mailinglist. I do read your build reports after each -rcN but there are only some modpost warnings in 6.10-rc7 https://lore.kernel.org/all/20240710083744.2885335-1-geert@linux-m68k.org/
Hi, please pull the changes described below. The hilights are new logic behind background block group reclaim, automatic removal of qgroup after removing a subvolume and new 'rescue=' mount options. The rest is optimizations, cleanups and refactoring. There's a merge conflict caused by the latency fixes from last week in extent_map.c:btrfs_scan_inode(), related commits 4e660ca3a98d931809734 and b3ebb9b7e92a928344a. Resolved in branch for-6.11-merged and that's been in linux-next for a few days. User visible features: - dynamic block group reclaim: - tunable framework to avoid situations where eager data allocations prevent creating new metadata chunks due to lack of unallocated space - reuse sysfs knob bg_reclaim_threshold (otherwise used only in zoned mode) for a fixed value threshold - new on/off sysfs knob "dynamic_reclaim" calculating the value based on heuristics, aiming to keep spare working space for relocating chunks but not to needlessly relocate partially utilized block groups or reclaim newly allocated ones - stats are exported in sysfs per block group type, files "reclaim_*" - this may increase IO load at unexpected times but the corner case of no allocatable block groups is known to be worse - automatically remove qgroup of deleted subvolumes - adjust qgroup removal conditions, make sure all related subvolume data are already removed, or return EBUSY, also take into account setting of sysfs drop_subtree_threshold - also works in squota mode - mount option updates: new modes of 'rescue=' that allow to mount (as read-only) images that could have been partially converted by user space tools - ignoremetacsums - invalid metadata checksums are ignored - ignoresuperflags - super block flags that track conversion in progress (like UUID or checksums) Core: - size of struct btrfs_inode is now below 1024 (on a release config), improved memory packing and other secondary effects - switch tracking of open inodes from rb-tree to xarray, minor performance improvement - reduce number of empty transaction commits when there are no dirty data/metadata - memory allocation optimizations (reduced numbers, reordering out of critical sections) - extent map structure optimizations and refactoring, more sanity checks - more subpage in zoned mode preparations or fixes - general snapshot code cleanups, improvements and documentation - tree-checker updates: more file extent ram_bytes fixes, continued - raid-stripe-tree update (not backward compatible): - remove extent encoding field from the structure, can be inferred from other information - requires btrfs-progs 6.9.1 or newer - cleanups and refactoring - error message updates - error handling improvements - return type and parameter cleanups and improvements ---------------------------------------------------------------- The following changes since commit 256abd8e550ce977b728be79a74e1729438b4948: Linux 6.10-rc7 (2024-07-07 14:23:46 -0700) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git tags/for-6.11-tag for you to fetch changes up to 8e7860543a94784d744c7ce34b78a2e11beefa5c: btrfs: fix extent map use-after-free when adding pages to compressed bio (2024-07-11 16:32:22 +0200) ---------------------------------------------------------------- Anand Jain (7): btrfs: drop bytenr_orig and fix comment in btrfs_scan_one_device() btrfs: move btrfs_block_group_root() to block-group.c btrfs: rename err to ret in btrfs_cleanup_fs_roots() btrfs: rename ret to err in btrfs_recover_relocation() btrfs: rename ret to ret2 in btrfs_recover_relocation() btrfs: rename err to ret in btrfs_recover_relocation() btrfs: rename err to ret in btrfs_drop_snapshot() Boris Burkov (7): btrfs: preallocate ulist memory for qgroup rsv btrfs: report reclaim stats in sysfs btrfs: store fs_info in space_info btrfs: dynamic block_group reclaim threshold btrfs: periodic block_group reclaim btrfs: prevent pathological periodic reclaim loops btrfs: urgent periodic reclaim pass David Sterba (24): btrfs: qgroup: do quick checks if quotas are enabled before starting ioctls btrfs: remove duplicate name variable declarations btrfs: rename macro local variables that clash with other variables btrfs: use for-local variables that shadow function variables btrfs: remove unused define EXTENT_SIZE_PER_ITEM btrfs: keep const when returning value from get_unaligned_le8() btrfs: constify parameters of write_eb_member() and its users btrfs: simplify range parameters of btrfs_wait_ordered_roots() btrfs: constify pointer parameters where applicable btrfs: abort transaction if we don't find extref in btrfs_del_inode_extref() btrfs: only print error message when checking item size in print_extent_item() btrfs: abort transaction on errors in btrfs_free_chunk() btrfs: qgroup: preallocate memory before adding a relation btrfs: qgroup: warn about inconsistent qgroups when relation update fails btrfs: pass a btrfs_inode to btrfs_readdir_put_delayed_items() btrfs: pass a btrfs_inode to btrfs_readdir_get_delayed_items() btrfs: pass a btrfs_inode to is_data_inode() btrfs: switch btrfs_block_group::inode to struct btrfs_inode btrfs: pass a btrfs_inode to btrfs_ioctl_send() btrfs: switch btrfs_pending_snapshot::dir to btrfs_inode btrfs: switch btrfs_ordered_extent::inode to struct btrfs_inode btrfs: pass a btrfs_inode to btrfs_compress_heuristic() btrfs: pass a btrfs_inode to btrfs_set_prop() btrfs: enhance compression error messages Filipe Manana (51): btrfs: zoned: make btrfs_get_dev_zone() static btrfs: remove no longer used btrfs_migrate_to_delayed_refs_rsv() btrfs: fix misspelled end IO compression callbacks btrfs: fix function name in comment for btrfs_remove_ordered_extent() btrfs: use an xarray to track open inodes in a root btrfs: preallocate inodes xarray entry to avoid transaction abort btrfs: reduce nesting and deduplicate error handling at btrfs_iget_path() btrfs: remove inode_lock from struct btrfs_root and use xarray locks btrfs: unify index_cnt and csum_bytes from struct btrfs_inode btrfs: don't allocate file extent tree for non regular files btrfs: remove location key from struct btrfs_inode btrfs: remove objectid from struct btrfs_inode on 64 bits platforms btrfs: rename rb_root member of extent_map_tree from map to root btrfs: use a regular rb_root instead of cached rb_root for extent_map_tree btrfs: make btrfs_finish_ordered_extent() return void btrfs: use a btrfs_inode in the log context (struct btrfs_log_ctx) btrfs: pass a btrfs_inode to btrfs_fdatawrite_range() btrfs: pass a btrfs_inode to btrfs_wait_ordered_range() btrfs: use a btrfs_inode local variable at btrfs_sync_file() btrfs: qgroup: avoid start/commit empty transaction when flushing reservations btrfs: avoid create and commit empty transaction when committing super btrfs: send: make ensure_commit_roots_uptodate() simpler and more efficient btrfs: send: avoid create/commit empty transaction at ensure_commit_roots_uptodate() btrfs: scrub: avoid create/commit empty transaction at finish_extent_writes_for_zoned() btrfs: add and use helper to commit the current transaction btrfs: send: get rid of the label and gotos at ensure_commit_roots_uptodate() btrfs: move fiemap code into its own file btrfs: reduce critical section at btrfs_wait_ordered_roots() btrfs: reduce critical section at btrfs_wait_ordered_extents() btrfs: add comment about locking to btrfs_split_ordered_extent() btrfs: avoid removal and re-insertion of split ordered extent btrfs: mark ordered extent insertion failure checks as unlikely btrfs: update panic message when splitting ordered extent btrfs: remove pointless code when creating and deleting a subvolume btrfs: avoid transaction commit on any fsync after subvolume creation btrfs: remove super block argument from btrfs_iget() btrfs: remove super block argument from btrfs_iget_path() btrfs: remove super block argument from btrfs_iget_locked() btrfs: do not BUG_ON() when freeing tree block after error btrfs: use label to deduplicate error path at btrfs_force_cow_block() btrfs: remove NULL transaction support for btrfs_lookup_extent_info() btrfs: simplify setting the full backref flag at update_ref_for_cow() btrfs: replace BUG_ON() with error handling at update_ref_for_cow() btrfs: remove superfluous metadata check at btrfs_lookup_extent_info() btrfs: reduce nesting for extent processing at btrfs_lookup_extent_info() btrfs: don't BUG_ON() when 0 reference count at btrfs_lookup_extent_info() btrfs: avoid allocating and running pointless delayed extent operations btrfs: move the direct IO code into its own file btrfs: fix data race when accessing the last_trans field of a root btrfs: fix bitmap leak when loading free space cache on duplicate entry btrfs: fix extent map use-after-free when adding pages to compressed bio Jeff Johnson (1): btrfs: add MODULE_DESCRIPTION() Johannes Thumshirn (8): btrfs: pass struct btrfs_io_geometry into handle_ops_on_dev_replace() btrfs: pass reloc_control to relocate_data_extent() btrfs: pass a reloc_control to relocate_file_extent_cluster() btrfs: pass a reloc_control to relocate_one_folio() btrfs: don't pass fs_info to describe_relocation() btrfs: pass a struct reloc_control to prealloc_file_extent_cluster() btrfs: pass reloc_control to setup_relocation_extent_mapping() btrfs: remove raid-stripe-tree encoding field from stripe_extent Josef Bacik (15): btrfs: don't do extra find_extent_buffer() in do_walk_down() btrfs: remove all extra btrfs_check_eb_owner() calls btrfs: use btrfs_read_extent_buffer() in do_walk_down() btrfs: push lookup_info into struct walk_control btrfs: factor out eb uptodate check from do_walk_down() btrfs: remove local variable need_account in do_walk_down() btrfs: unify logic to decide if we need to walk down into a node during snapshot delete btrfs: extract the reference dropping code into it's own helper btrfs: don't BUG_ON on ENOMEM from btrfs_lookup_extent_info() in walk_down_proc() btrfs: handle errors from ref mods during UPDATE_BACKREF in walk_down_proc() btrfs: replace BUG_ON with ASSERT in walk_down_proc() btrfs: clean up our handling of refs == 0 in snapshot delete btrfs: convert correctness BUG_ON()'s to ASSERT()'s in walk_up_proc() btrfs: handle errors from btrfs_dec_ref() properly btrfs: add documentation around snapshot delete Junchao Sun (1): btrfs: qgroup: delete a TODO about using kmem cache to allocate structures Mark Harmstone (1): btrfs: fix typo in error message in btrfs_validate_super() Qu Wenruo (37): btrfs: raid56: do extra dumping for CONFIG_BTRFS_ASSERT btrfs: slightly loosen the requirement for qgroup removal btrfs: automatically remove the subvolume qgroup btrfs: rename extent_map::orig_block_len to disk_num_bytes btrfs: export the expected file extent through can_nocow_extent() btrfs: introduce new members for extent_map btrfs: introduce extra sanity checks for extent maps btrfs: remove extent_map::orig_start member btrfs: remove extent_map::block_len member btrfs: remove extent_map::block_start member btrfs: cleanup duplicated parameters related to can_nocow_file_extent_args btrfs: cleanup duplicated parameters related to btrfs_alloc_ordered_extent btrfs: cleanup duplicated parameters related to create_io_em() btrfs: cleanup duplicated parameters related to btrfs_create_dio_extent() btrfs: make __extent_writepage_io() to write specified range only btrfs: subpage: introduce helpers to handle subpage delalloc locking btrfs: lock subpage ranges in one go for writepage_delalloc() btrfs: do not clear page dirty inside extent_write_locked_range() btrfs: make extent_write_locked_range() handle subpage writeback correctly btrfs: cleanup recursive include of the same header btrfs: do not directly include rwlock_types.h btrfs: uapi: record temporary super flags used by btrfstune btrfs: subpage: remove the unused error bitmap dumping btrfs: print-tree: add generation and type dump for EXTENT_DATA_KEY btrfs: cleanup the bytenr usage inside btrfs_extent_item_to_extent_map() btrfs: ignore incorrect btrfs_file_extent_item::ram_bytes btrfs: make validate_extent_map() catch ram_bytes mismatch btrfs: fix the ram_bytes assignment for truncated ordered extents btrfs: tree-checker: add extra ram_bytes and disk_num_bytes check btrfs: remove unused Opt enums btrfs: output the unrecognized super block flags as hex btrfs: introduce new "rescue=ignoremetacsums" mount option btrfs: introduce new "rescue=ignoresuperflags" mount option btrfs: remove the extra_gfp parameter from btrfs_alloc_folio_array() btrfs: rename the extra_gfp parameter of btrfs_alloc_page_array() btrfs: move extent_range_clear_dirty_for_io() into inode.c btrfs: remove the BUG_ON() inside extent_range_clear_dirty_for_io() fs/btrfs/Makefile | 2 +- fs/btrfs/accessors.h | 15 +- fs/btrfs/bio.c | 4 +- fs/btrfs/block-group.c | 53 +- fs/btrfs/block-group.h | 3 +- fs/btrfs/btrfs_inode.h | 156 ++-- fs/btrfs/compression.c | 25 +- fs/btrfs/compression.h | 2 +- fs/btrfs/ctree.c | 108 +-- fs/btrfs/ctree.h | 18 +- fs/btrfs/defrag.c | 18 +- fs/btrfs/delalloc-space.c | 2 +- fs/btrfs/delalloc-space.h | 2 +- fs/btrfs/delayed-inode.c | 47 +- fs/btrfs/delayed-inode.h | 10 +- fs/btrfs/delayed-ref.c | 51 +- fs/btrfs/delayed-ref.h | 8 +- fs/btrfs/dev-replace.c | 4 +- fs/btrfs/dir-item.c | 8 +- fs/btrfs/dir-item.h | 6 +- fs/btrfs/direct-io.c | 1052 ++++++++++++++++++++++++++ fs/btrfs/direct-io.h | 14 + fs/btrfs/disk-io.c | 128 ++-- fs/btrfs/disk-io.h | 18 +- fs/btrfs/export.c | 6 +- fs/btrfs/extent-io-tree.c | 4 + fs/btrfs/extent-tree.c | 685 ++++++++++------- fs/btrfs/extent-tree.h | 8 +- fs/btrfs/extent_io.c | 1092 ++++----------------------- fs/btrfs/extent_io.h | 19 +- fs/btrfs/extent_map.c | 246 +++++-- fs/btrfs/extent_map.h | 56 +- fs/btrfs/fiemap.c | 930 +++++++++++++++++++++++ fs/btrfs/fiemap.h | 11 + fs/btrfs/file-item.c | 52 +- fs/btrfs/file.c | 355 +-------- fs/btrfs/file.h | 4 +- fs/btrfs/free-space-cache.c | 12 +- fs/btrfs/free-space-tree.c | 10 +- fs/btrfs/fs.h | 17 +- fs/btrfs/inode-item.c | 4 +- fs/btrfs/inode.c | 1475 ++++++++----------------------------- fs/btrfs/ioctl.c | 94 ++- fs/btrfs/ioctl.h | 2 +- fs/btrfs/locking.h | 1 - fs/btrfs/lru_cache.h | 1 - fs/btrfs/lzo.c | 43 +- fs/btrfs/messages.c | 3 +- fs/btrfs/misc.h | 4 +- fs/btrfs/ordered-data.c | 146 ++-- fs/btrfs/ordered-data.h | 27 +- fs/btrfs/print-tree.c | 10 +- fs/btrfs/props.c | 20 +- fs/btrfs/props.h | 4 +- fs/btrfs/qgroup.c | 221 ++++-- fs/btrfs/qgroup.h | 25 +- fs/btrfs/raid-stripe-tree.c | 13 - fs/btrfs/raid-stripe-tree.h | 3 +- fs/btrfs/raid56.c | 118 ++- fs/btrfs/reflink.c | 8 +- fs/btrfs/relocation.c | 157 ++-- fs/btrfs/scrub.c | 13 +- fs/btrfs/send.c | 49 +- fs/btrfs/send.h | 4 +- fs/btrfs/space-info.c | 265 ++++++- fs/btrfs/space-info.h | 48 ++ fs/btrfs/subpage.c | 162 +++- fs/btrfs/subpage.h | 9 +- fs/btrfs/super.c | 51 +- fs/btrfs/super.h | 2 +- fs/btrfs/sysfs.c | 85 ++- fs/btrfs/tests/btrfs-tests.c | 5 +- fs/btrfs/tests/extent-map-tests.c | 120 +-- fs/btrfs/tests/inode-tests.c | 176 +++-- fs/btrfs/transaction.c | 31 +- fs/btrfs/transaction.h | 9 +- fs/btrfs/tree-checker.c | 37 +- fs/btrfs/tree-log.c | 74 +- fs/btrfs/tree-log.h | 6 +- fs/btrfs/ulist.c | 21 +- fs/btrfs/ulist.h | 2 + fs/btrfs/uuid-tree.c | 10 +- fs/btrfs/uuid-tree.h | 4 +- fs/btrfs/volumes.c | 62 +- fs/btrfs/volumes.h | 2 +- fs/btrfs/xattr.c | 4 +- fs/btrfs/xattr.h | 2 +- fs/btrfs/zlib.c | 56 +- fs/btrfs/zoned.c | 30 +- fs/btrfs/zoned.h | 11 +- fs/btrfs/zstd.c | 70 +- include/trace/events/btrfs.h | 19 +- include/uapi/linux/btrfs_tree.h | 22 +- 93 files changed, 5186 insertions(+), 3915 deletions(-) create mode 100644 fs/btrfs/direct-io.c create mode 100644 fs/btrfs/direct-io.h create mode 100644 fs/btrfs/fiemap.c create mode 100644 fs/btrfs/fiemap.h