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2024-12-03Merge tag 'for-6.13-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - add lockdep annotations for io_uring/encoded read integration, inode lock is held when returning to userspace - properly reflect experimental config option to sysfs - handle NULL root in case the rescue mode accepts invalid/damaged tree roots (rescue=ibadroot) - regression fix of a deadlock between transaction and extent locks - fix pending bio accounting bug in encoded read ioctl - fix NOWAIT mode when checking references for NOCOW files - fix use-after-free in a rb-tree cleanup in ref-verify debugging tool * tag 'for-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix lockdep warnings on io_uring encoded reads btrfs: ref-verify: fix use-after-free after invalid ref action btrfs: add a sanity check for btrfs root in btrfs_search_slot() btrfs: don't loop for nowait writes when checking for cross references btrfs: sysfs: advertise experimental features only if CONFIG_BTRFS_EXPERIMENTAL=y btrfs: fix deadlock between transaction commits and extent locks btrfs: fix use-after-free in btrfs_encoded_read_endio()
2024-11-29btrfs: fix lockdep warnings on io_uring encoded readsMark Harmstone
Lockdep doesn't like the fact that btrfs_uring_read_extent() returns to userspace still holding the inode lock, even though we release it once the I/O finishes. Add calls to rwsem_release() and rwsem_acquire_read() to work round this. Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> 34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)") Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29btrfs: ref-verify: fix use-after-free after invalid ref actionFilipe Manana
At btrfs_ref_tree_mod() after we successfully inserted the new ref entry (local variable 'ref') into the respective block entry's rbtree (local variable 'be'), if we find an unexpected action of BTRFS_DROP_DELAYED_REF, we error out and free the ref entry without removing it from the block entry's rbtree. Then in the error path of btrfs_ref_tree_mod() we call btrfs_free_ref_cache(), which iterates over all block entries and then calls free_block_entry() for each one, and there we will trigger a use-after-free when we are called against the block entry to which we added the freed ref entry to its rbtree, since the rbtree still points to the block entry, as we didn't remove it from the rbtree before freeing it in the error path at btrfs_ref_tree_mod(). Fix this by removing the new ref entry from the rbtree before freeing it. Syzbot report this with the following stack traces: BTRFS error (device loop0 state EA): Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615 __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523 update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4314 btrfs_insert_empty_item fs/btrfs/ctree.h:669 [inline] btrfs_insert_orphan_item+0x1f1/0x320 fs/btrfs/orphan.c:23 btrfs_orphan_add+0x6d/0x1a0 fs/btrfs/inode.c:3482 btrfs_unlink+0x267/0x350 fs/btrfs/inode.c:4293 vfs_unlink+0x365/0x650 fs/namei.c:4469 do_unlinkat+0x4ae/0x830 fs/namei.c:4533 __do_sys_unlinkat fs/namei.c:4576 [inline] __se_sys_unlinkat fs/namei.c:4569 [inline] __x64_sys_unlinkat+0xcc/0xf0 fs/namei.c:4569 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f BTRFS error (device loop0 state EA): Ref action 1, root 5, ref_root 5, parent 0, owner 260, offset 0, num_refs 1 __btrfs_mod_ref+0x76b/0xac0 fs/btrfs/extent-tree.c:2521 update_ref_for_cow+0x96a/0x11f0 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411 __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline] __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137 __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171 btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313 prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586 relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538 BTRFS error (device loop0 state EA): Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615 __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523 update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411 __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline] __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137 __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171 btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313 prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586 relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538 ================================================================== BUG: KASAN: slab-use-after-free in rb_first+0x69/0x70 lib/rbtree.c:473 Read of size 8 at addr ffff888042d1af38 by task syz.0.0/5329 CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted 6.12.0-rc7-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 rb_first+0x69/0x70 lib/rbtree.c:473 free_block_entry+0x78/0x230 fs/btrfs/ref-verify.c:248 btrfs_free_ref_cache+0xa3/0x100 fs/btrfs/ref-verify.c:917 btrfs_ref_tree_mod+0x139f/0x15e0 fs/btrfs/ref-verify.c:898 btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544 __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523 update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411 __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline] __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137 __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171 btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313 prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586 relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f996df7e719 RSP: 002b:00007f996ede7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f996e135f80 RCX: 00007f996df7e719 RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000004 RBP: 00007f996dff139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f996e135f80 R15: 00007fff79f32e68 </TASK> Allocated by task 5329: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:257 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] btrfs_ref_tree_mod+0x264/0x15e0 fs/btrfs/ref-verify.c:701 btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544 __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523 update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411 __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline] __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137 __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171 btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313 prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586 relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5329: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x1a0/0x440 mm/slub.c:4727 btrfs_ref_tree_mod+0x136c/0x15e0 btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544 __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523 update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512 btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594 btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754 btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411 __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030 btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline] __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137 __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171 btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313 prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586 relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611 btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377 __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161 btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888042d1af00 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 56 bytes inside of freed 64-byte region [ffff888042d1af00, ffff888042d1af40) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42d1a anon flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000000 ffff88801ac418c0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5055, tgid 5055 (dhcpcd-run-hook), ts 40377240074, free_ts 40376848335 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1541 prep_new_page mm/page_alloc.c:1549 [inline] get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3459 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4735 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2412 allocate_slab+0x5a/0x2f0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818 __slab_alloc+0x58/0xa0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] __do_kmalloc_node mm/slub.c:4263 [inline] __kmalloc_noprof+0x25a/0x400 mm/slub.c:4276 kmalloc_noprof include/linux/slab.h:882 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771 security_file_open+0x777/0x990 security/security.c:3109 do_dentry_open+0x369/0x1460 fs/open.c:945 vfs_open+0x3e/0x330 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3933 page last free pid 5055 tgid 5055 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1112 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2642 free_pipe_info+0x300/0x390 fs/pipe.c:860 put_pipe_info fs/pipe.c:719 [inline] pipe_release+0x245/0x320 fs/pipe.c:742 __fput+0x23f/0x880 fs/file_table.c:431 __do_sys_close fs/open.c:1567 [inline] __se_sys_close fs/open.c:1552 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1552 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888042d1ae00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888042d1ae80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc >ffff888042d1af00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888042d1af80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ffff888042d1b000: 00 00 00 00 00 fc fc 00 00 00 00 00 fc fc 00 00 Reported-by: syzbot+7325f164162e200000c1@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/673723eb.050a0220.1324f8.00a8.GAE@google.com/T/#u Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29btrfs: add a sanity check for btrfs root in btrfs_search_slot()Lizhi Xu
Syzbot reports a null-ptr-deref in btrfs_search_slot(). The reproducer is using rescue=ibadroots, and the extent tree root is corrupted thus the extent tree is NULL. When scrub tries to search the extent tree to gather the needed extent info, btrfs_search_slot() doesn't check if the target root is NULL or not, resulting the null-ptr-deref. Add sanity check for btrfs root before using it in btrfs_search_slot(). Reported-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com Fixes: 42437a6386ff ("btrfs: introduce mount option rescue=ignorebadroots") Link: https://syzkaller.appspot.com/bug?extid=3030e17bd57a73d39bd7 CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Qu Wenruo <wqu@suse.com> Tested-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29btrfs: don't loop for nowait writes when checking for cross referencesFilipe Manana
When checking for delayed refs when verifying if there are cross references for a data extent, we stop if the path has nowait set and we can't try lock the delayed ref head's mutex, returning -EAGAIN with the goal of making a write fallback to a blocking context. However we ignore the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns it, and keep looping instead of immediately returning the -EAGAIN to the caller. Fix this by not looping if we get -EAGAIN and we have a nowait path. Fixes: 26ce91144631 ("btrfs: make can_nocow_extent nowait compatible") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28btrfs: sysfs: advertise experimental features only if ↵Filipe Manana
CONFIG_BTRFS_EXPERIMENTAL=y We are advertising experimental features through sysfs if CONFIG_BTRFS_DEBUG is set, without looking if CONFIG_BTRFS_EXPERIMENTAL is set. This is wrong as it will result in reporting experimental features as supported when CONFIG_BTRFS_EXPERIMENTAL is not set but CONFIG_BTRFS_DEBUG is set. Fix this by checking for CONFIG_BTRFS_EXPERIMENTAL instead of CONFIG_BTRFS_DEBUG. Fixes: 67cd3f221769 ("btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG") Reviewed-by: Neal Gompa <neal@gompa.dev> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28btrfs: fix deadlock between transaction commits and extent locksFilipe Manana
When running a workload with fsstress and duperemove (generic/561) we can hit a deadlock related to transaction commits and locking extent ranges, as described below. Task A hanging during a transaction commit, waiting for all other writers to complete: [178317.334817] INFO: task fsstress:555623 blocked for more than 120 seconds. [178317.335693] Not tainted 6.12.0-rc6-btrfs-next-179+ #1 [178317.336528] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [178317.337673] task:fsstress state:D stack:0 pid:555623 tgid:555623 ppid:555620 flags:0x00004002 [178317.337679] Call Trace: [178317.337681] <TASK> [178317.337685] __schedule+0x364/0xbe0 [178317.337691] schedule+0x26/0xa0 [178317.337695] btrfs_commit_transaction+0x5c5/0x1050 [btrfs] [178317.337769] ? start_transaction+0xc4/0x800 [btrfs] [178317.337815] ? __pfx_autoremove_wake_function+0x10/0x10 [178317.337819] btrfs_mksubvol+0x381/0x640 [btrfs] [178317.337878] btrfs_mksnapshot+0x7a/0xb0 [btrfs] [178317.337935] __btrfs_ioctl_snap_create+0x1bb/0x1d0 [btrfs] [178317.337995] btrfs_ioctl_snap_create_v2+0x103/0x130 [btrfs] [178317.338053] btrfs_ioctl+0x29b/0x2a90 [btrfs] [178317.338118] ? kmem_cache_alloc_noprof+0x5f/0x2c0 [178317.338126] ? getname_flags+0x45/0x1f0 [178317.338133] ? _raw_spin_unlock+0x15/0x30 [178317.338145] ? __x64_sys_ioctl+0x88/0xc0 [178317.338149] __x64_sys_ioctl+0x88/0xc0 [178317.338152] do_syscall_64+0x4a/0x110 [178317.338160] entry_SYSCALL_64_after_hwframe+0x76/0x7e [178317.338190] RIP: 0033:0x7f13c28e271b Which corresponds to line 2361 of transaction.c: $ cat -n fs/btrfs/transaction.c (...) 2162 int btrfs_commit_transaction(struct btrfs_trans_handle *trans) 2163 { (...) 2349 spin_lock(&fs_info->trans_lock); 2350 add_pending_snapshot(trans); 2351 cur_trans->state = TRANS_STATE_COMMIT_DOING; 2352 spin_unlock(&fs_info->trans_lock); 2353 2354 /* 2355 * The thread has started/joined the transaction thus it holds the 2356 * lockdep map as a reader. It has to release it before acquiring the 2357 * lockdep map as a writer. 2358 */ 2359 btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); 2360 btrfs_might_wait_for_event(fs_info, btrfs_trans_num_writers); 2361 wait_event(cur_trans->writer_wait, 2362 atomic_read(&cur_trans->num_writers) == 1); (...) The transaction is in the TRANS_STATE_COMMIT_DOING state and so it's waiting for all other existing writers to complete and release their transaction handle. Task B is running ordered extent completion and blocked waiting to lock an extent range in an inode's io tree: [178317.327411] INFO: task kworker/u48:8:554545 blocked for more than 120 seconds. [178317.328630] Not tainted 6.12.0-rc6-btrfs-next-179+ #1 [178317.329635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [178317.330872] task:kworker/u48:8 state:D stack:0 pid:554545 tgid:554545 ppid:2 flags:0x00004000 [178317.330878] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] [178317.330944] Call Trace: [178317.330945] <TASK> [178317.330947] __schedule+0x364/0xbe0 [178317.330952] schedule+0x26/0xa0 [178317.330955] __lock_extent+0x337/0x3a0 [btrfs] [178317.331014] ? __pfx_autoremove_wake_function+0x10/0x10 [178317.331017] btrfs_finish_one_ordered+0x47a/0xaa0 [btrfs] [178317.331074] ? psi_group_change+0x132/0x2d0 [178317.331078] btrfs_work_helper+0xbd/0x370 [btrfs] [178317.331140] process_scheduled_works+0xd3/0x460 [178317.331144] ? __pfx_worker_thread+0x10/0x10 [178317.331146] worker_thread+0x121/0x250 [178317.331149] ? __pfx_worker_thread+0x10/0x10 [178317.331151] kthread+0xe9/0x120 [178317.331154] ? __pfx_kthread+0x10/0x10 [178317.331157] ret_from_fork+0x2d/0x50 [178317.331159] ? __pfx_kthread+0x10/0x10 [178317.331162] ret_from_fork_asm+0x1a/0x30 This extent range locking happens after joining the current transaction, so task A is waiting for task B to release its transaction handle (decrementing the transaction's num_writers counter). Task C while doing a fiemap it tries to join the current transaction: [242682.812815] task:pool state:D stack:0 pid:560767 tgid:560724 ppid:555622 flags:0x00004006 [242682.812827] Call Trace: [242682.812856] <TASK> [242682.812864] __schedule+0x364/0xbe0 [242682.812879] ? _raw_spin_unlock_irqrestore+0x23/0x40 [242682.812897] schedule+0x26/0xa0 [242682.812909] wait_current_trans+0xd6/0x130 [btrfs] [242682.813148] ? __pfx_autoremove_wake_function+0x10/0x10 [242682.813162] start_transaction+0x3d4/0x800 [btrfs] [242682.813399] btrfs_is_data_extent_shared+0xd2/0x440 [btrfs] [242682.813723] fiemap_process_hole+0x2a2/0x300 [btrfs] [242682.813995] extent_fiemap+0x9b8/0xb80 [btrfs] [242682.814249] btrfs_fiemap+0x78/0xc0 [btrfs] [242682.814501] do_vfs_ioctl+0x2db/0xa50 [242682.814519] __x64_sys_ioctl+0x6a/0xc0 [242682.814531] do_syscall_64+0x4a/0x110 [242682.814544] entry_SYSCALL_64_after_hwframe+0x76/0x7e [242682.814556] RIP: 0033:0x7efff595e71b It tries to join the current transaction, but it can't because the transaction is in the TRANS_STATE_COMMIT_DOING state, so join_transaction() returns -EBUSY to start_transaction() and makes it wait for the current transaction to complete. And while it's waiting for the transaction to complete, it's holding an extent range locked in the same inode that task B is operating, which causes a deadlock between these 3 tasks. The extent range for the inode was locked at the start of the fiemap operation, early at extent_fiemap(). In short these tasks deadlock because: 1) Task A is waiting for task B to release its transaction handle; 2) Task B is waiting to lock an extent range for an inode while holding a transaction handle open; 3) Task C is waiting for the current transaction to complete (for task A to finish the transaction commit) while holding the extent range for the inode locked, so task B can't progress and release its transaction handle. This results in an ABBA deadlock involving transaction commits and extent locks. Extent locks are higher level locks, like inode VFS locks, and should always be acquired before joining or starting a transaction, but recently commit 2206265f41e9 ("btrfs: remove code duplication in ordered extent finishing") accidentally changed btrfs_finish_one_ordered() to do the transaction join before locking the extent range. Fix this by making sure that btrfs_finish_one_ordered() always locks the extent before joining a transaction and add an explicit comment about the need for this order. Fixes: 2206265f41e9 ("btrfs: remove code duplication in ordered extent finishing") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28btrfs: fix use-after-free in btrfs_encoded_read_endio()Johannes Thumshirn
Shinichiro reported the following use-after free that sometimes is happening in our CI system when running fstests' btrfs/284 on a TCMU runner device: BUG: KASAN: slab-use-after-free in lock_release+0x708/0x780 Read of size 8 at addr ffff888106a83f18 by task kworker/u80:6/219 CPU: 8 UID: 0 PID: 219 Comm: kworker/u80:6 Not tainted 6.12.0-rc6-kts+ #15 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] Call Trace: <TASK> dump_stack_lvl+0x6e/0xa0 ? lock_release+0x708/0x780 print_report+0x174/0x505 ? lock_release+0x708/0x780 ? __virt_addr_valid+0x224/0x410 ? lock_release+0x708/0x780 kasan_report+0xda/0x1b0 ? lock_release+0x708/0x780 ? __wake_up+0x44/0x60 lock_release+0x708/0x780 ? __pfx_lock_release+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 ? lock_is_held_type+0x9a/0x110 _raw_spin_unlock_irqrestore+0x1f/0x60 __wake_up+0x44/0x60 btrfs_encoded_read_endio+0x14b/0x190 [btrfs] btrfs_check_read_bio+0x8d9/0x1360 [btrfs] ? lock_release+0x1b0/0x780 ? trace_lock_acquire+0x12f/0x1a0 ? __pfx_btrfs_check_read_bio+0x10/0x10 [btrfs] ? process_one_work+0x7e3/0x1460 ? lock_acquire+0x31/0xc0 ? process_one_work+0x7e3/0x1460 process_one_work+0x85c/0x1460 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5e6/0xfc0 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c3/0x3a0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 3661: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 btrfs_encoded_read_regular_fill_pages+0x16c/0x6d0 [btrfs] send_extent_data+0xf0f/0x24a0 [btrfs] process_extent+0x48a/0x1830 [btrfs] changed_cb+0x178b/0x2ea0 [btrfs] btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs] _btrfs_ioctl_send+0x117/0x330 [btrfs] btrfs_ioctl+0x184a/0x60a0 [btrfs] __x64_sys_ioctl+0x12e/0x1a0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 3661: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x70 __kasan_slab_free+0x4f/0x70 kfree+0x143/0x490 btrfs_encoded_read_regular_fill_pages+0x531/0x6d0 [btrfs] send_extent_data+0xf0f/0x24a0 [btrfs] process_extent+0x48a/0x1830 [btrfs] changed_cb+0x178b/0x2ea0 [btrfs] btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs] _btrfs_ioctl_send+0x117/0x330 [btrfs] btrfs_ioctl+0x184a/0x60a0 [btrfs] __x64_sys_ioctl+0x12e/0x1a0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff888106a83f00 which belongs to the cache kmalloc-rnd-07-96 of size 96 The buggy address is located 24 bytes inside of freed 96-byte region [ffff888106a83f00, ffff888106a83f60) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106a83800 pfn:0x106a83 flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) page_type: f5(slab) raw: 0017ffffc0000000 ffff888100053680 ffffea0004917200 0000000000000004 raw: ffff888106a83800 0000000080200019 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888106a83e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888106a83e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888106a83f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888106a83f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888106a84000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Further analyzing the trace and the crash dump's vmcore file shows that the wake_up() call in btrfs_encoded_read_endio() is calling wake_up() on the wait_queue that is in the private data passed to the end_io handler. Commit 4ff47df40447 ("btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()") moved 'struct btrfs_encoded_read_private' off the stack. Before that commit one can see a corruption of the private data when analyzing the vmcore after a crash: *(struct btrfs_encoded_read_private *)0xffff88815626eec8 = { .wait = (wait_queue_head_t){ .lock = (spinlock_t){ .rlock = (struct raw_spinlock){ .raw_lock = (arch_spinlock_t){ .val = (atomic_t){ .counter = (int)-2005885696, }, .locked = (u8)0, .pending = (u8)157, .locked_pending = (u16)40192, .tail = (u16)34928, }, .magic = (unsigned int)536325682, .owner_cpu = (unsigned int)29, .owner = (void *)__SCT__tp_func_btrfs_transaction_commit+0x0 = 0x0, .dep_map = (struct lockdep_map){ .key = (struct lock_class_key *)0xffff8881575a3b6c, .class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 }, .name = (const char *)0xffff88815626f100 = "", .wait_type_outer = (u8)37, .wait_type_inner = (u8)178, .lock_type = (u8)154, }, }, .__padding = (u8 [24]){ 0, 157, 112, 136, 50, 174, 247, 31, 29 }, .dep_map = (struct lockdep_map){ .key = (struct lock_class_key *)0xffff8881575a3b6c, .class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 }, .name = (const char *)0xffff88815626f100 = "", .wait_type_outer = (u8)37, .wait_type_inner = (u8)178, .lock_type = (u8)154, }, }, .head = (struct list_head){ .next = (struct list_head *)0x112cca, .prev = (struct list_head *)0x47, }, }, .pending = (atomic_t){ .counter = (int)-1491499288, }, .status = (blk_status_t)130, } Here we can see several indicators of in-memory data corruption, e.g. the large negative atomic values of ->pending or ->wait->lock->rlock->raw_lock->val, as well as the bogus spinlock magic 0x1ff7ae32 (decimal 536325682 above) instead of 0xdead4ead or the bogus pointer values for ->wait->head. To fix this, change atomic_dec_return() to atomic_dec_and_test() to fix the corruption, as atomic_dec_return() is defined as two instructions on x86_64, whereas atomic_dec_and_test() is defined as a single atomic operation. This can lead to a situation where counter value is already decremented but the if statement in btrfs_encoded_read_endio() is not completely processed, i.e. the 0 test has not completed. If another thread continues executing btrfs_encoded_read_regular_fill_pages() the atomic_dec_return() there can see an already updated ->pending counter and continues by freeing the private data. Continuing in the endio handler the test for 0 succeeds and the wait_queue is woken up, resulting in a use-after-free. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Suggested-by: Damien Le Moal <Damien.LeMoal@wdc.com> Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-22Merge tag 'cxl-for-6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl updates from Dave Jiang: - Constify range_contains() input parameters to prevent changes - Add support for displaying RCD capabilities in sysfs to support lspci for CXL device - Downgrade warning message to debug in cxl_probe_component_regs() - Add support for adding a printf specifier '%pra' to emit 'struct range' content: - Add sanity tests for 'struct resource' - Add documentation for special case - Add %pra for 'struct range' - Add %pra usage in CXL code - Add preparation code for DCD support: - Add range_overlaps() - Add CDAT DSMAS table shared and read only flag in ACPICA - Add documentation to 'struct dev_dax_range' - Delay event buffer allocation in CXL PCI code until needed - Use guard() in cxl_dpa_set_mode() - Refactor create region code to consolidate common code * tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/region: Refactor common create region code cxl/hdm: Use guard() in cxl_dpa_set_mode() cxl/pci: Delay event buffer allocation dax: Document struct dev_dax_range ACPI/CDAT: Add CDAT/DSMAS shared and read only flag values range: Add range_overlaps() cxl/cdat: Use %pra for dpa range outputs printf: Add print format (%pra) for struct range Documentation/printf: struct resource add start == end special case test printf: Add very basic struct resource tests cxl: downgrade a warning message to debug level in cxl_probe_component_regs() cxl/pci: Add sysfs attribute for CXL 1.1 device link status cxl/core/regs: Add rcd_pcie_cap initialization kernel/range: Const-ify range_contains parameters
2024-11-18Merge tag 'for-6.13/block-20241118' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: - NVMe updates via Keith: - Use uring_cmd helper (Pavel) - Host Memory Buffer allocation enhancements (Christoph) - Target persistent reservation support (Guixin) - Persistent reservation tracing (Guixen) - NVMe 2.1 specification support (Keith) - Rotational Meta Support (Matias, Wang, Keith) - Volatile cache detection enhancment (Guixen) - MD updates via Song: - Maintainers update - raid5 sync IO fix - Enhance handling of faulty and blocked devices - raid5-ppl atomic improvement - md-bitmap fix - Support for manually defining embedded partition tables - Zone append fixes and cleanups - Stop sending the queued requests in the plug list to the driver ->queue_rqs() handle in reverse order. - Zoned write plug cleanups - Cleanups disk stats tracking and add support for disk stats for passthrough IO - Add preparatory support for file system atomic writes - Add lockdep support for queue freezing. Already found a bunch of issues, and some fixes for that are in here. More will be coming. - Fix race between queue stopping/quiescing and IO queueing - ublk recovery improvements - Fix ublk mmap for 64k pages - Various fixes and cleanups * tag 'for-6.13/block-20241118' of git://git.kernel.dk/linux: (118 commits) MAINTAINERS: Update git tree for mdraid subsystem block: make struct rq_list available for !CONFIG_BLOCK block/genhd: use seq_put_decimal_ull for diskstats decimal values block: don't reorder requests in blk_mq_add_to_batch block: don't reorder requests in blk_add_rq_to_plug block: add a rq_list type block: remove rq_list_move virtio_blk: reverse request order in virtio_queue_rqs nvme-pci: reverse request order in nvme_queue_rqs btrfs: validate queue limits block: export blk_validate_limits nvmet: add tracing of reservation commands nvme: parse reservation commands's action and rtype to string nvmet: report ns's vwc not present md/raid5: Increase r5conf.cache_name size block: remove the ioprio field from struct request block: remove the write_hint field from struct request nvme: check ns's volatile write cache not present nvme: add rotational support nvme: use command set independent id ns if available ...
2024-11-18Merge tag 'for-6.13-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Changes outside of btrfs: add io_uring command flag to track a dying task (the rest will go via the block git tree). User visible changes: - wire encoded read (ioctl) to io_uring commands, this can be used on itself, in the future this will allow 'send' to be asynchronous. As a consequence, the encoded read ioctl can also work in non-blocking mode - new ioctl to wait for cleaned subvolumes, no need to use the generic and root-only SEARCH_TREE ioctl, will be used by "btrfs subvol sync" - recognize different paths/symlinks for the same devices and don't report them during rescanning, this can be observed with LVM or DM - seeding device use case change, the sprout device (the one capturing new writes) will not clear the read-only status of the super block; this prevents accumulating space from deleted snapshots Performance improvements: - reduce lock contention when traversing extent buffers - reduce extent tree lock contention when searching for inline backref - switch from rb-trees to xarray for delayed ref tracking, improvements due to better cache locality, branching factors and more compact data structures - enable extent map shrinker again (prevent memory exhaustion under some types of IO load), reworked to run in a single worker thread (there used to be problems causing long stalls under memory pressure) Core changes: - raid-stripe-tree feature updates: - make device replace and scrub work - implement partial deletion of stripe extents - new selftests - split the config option BTRFS_DEBUG and add EXPERIMENTAL for features that are experimental or with known problems so we don't misuse debugging config for that - subpage mode updates (sector < page): - update compression implementations - update writepage, writeback - continued folio API conversions: - buffered writes - make buffered write copy one page at a time, preparatory work for future integration with large folios, may cause performance drop - proper locking of root item regarding starting send - error handling improvements - code cleanups and refactoring: - dead code removal - unused parameter reduction - lockdep assertions" * tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (119 commits) btrfs: send: check for read-only send root under critical section btrfs: send: check for dead send root under critical section btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap() btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl() btrfs: fix a typo in btrfs_use_zone_append btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read() btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot() btrfs: remove hole from struct btrfs_delayed_node btrfs: update stale comment for struct btrfs_delayed_ref_node::add_list btrfs: add new ioctl to wait for cleaned subvolumes btrfs: simplify range tracking in cow_file_range() btrfs: remove conditional path allocation in btrfs_read_locked_inode() btrfs: push cleanup into btrfs_read_locked_inode() io_uring/cmd: let cmds to know about dying task btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu() btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl) btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages() btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is set btrfs: change btrfs_encoded_read() so that reading of extent is done by caller btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read() ...
2024-11-18Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull 'struct fd' class updates from Al Viro: "The bulk of struct fd memory safety stuff Making sure that struct fd instances are destroyed in the same scope where they'd been created, getting rid of reassignments and passing them by reference, converting to CLASS(fd{,_pos,_raw}). We are getting very close to having the memory safety of that stuff trivial to verify" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) deal with the last remaing boolean uses of fd_file() css_set_fork(): switch to CLASS(fd_raw, ...) memcg_write_event_control(): switch to CLASS(fd) assorted variants of irqfd setup: convert to CLASS(fd) do_pollfd(): convert to CLASS(fd) convert do_select() convert vfs_dedupe_file_range(). convert cifs_ioctl_copychunk() convert media_request_get_by_fd() convert spu_run(2) switch spufs_calls_{get,put}() to CLASS() use convert cachestat(2) convert do_preadv()/do_pwritev() fdget(), more trivial conversions fdget(), trivial conversions privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget() o2hb_region_dev_store(): avoid goto around fdget()/fdput() introduce "fd_pos" class, convert fdget_pos() users to it. fdget_raw() users: switch to CLASS(fd_raw) convert vmsplice() to CLASS(fd) ...
2024-11-18Merge tag 'vfs-6.13.pagecache' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs pagecache updates from Christian Brauner: "Cleanup filesystem page flag usage: This continues the work to make the mappedtodisk/owner_2 flag available to filesystems which don't use buffer heads. Further patches remove uses of Private2. This brings us very close to being rid of it entirely" * tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: migrate: Remove references to Private2 ceph: Remove call to PagePrivate2() btrfs: Switch from using the private_2 flag to owner_2 mm: Remove PageMappedToDisk nilfs2: Convert nilfs_copy_buffer() to use folios fs: Move clearing of mappedtodisk to buffer.c
2024-11-18Merge tag 'vfs-6.13.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Fixup and improve NLM and kNFSD file lock callbacks Last year both GFS2 and OCFS2 had some work done to make their locking more robust when exported over NFS. Unfortunately, part of that work caused both NLM (for NFS v3 exports) and kNFSD (for NFSv4.1+ exports) to no longer send lock notifications to clients This in itself is not a huge problem because most NFS clients will still poll the server in order to acquire a conflicted lock It's important for NLM and kNFSD that they do not block their kernel threads inside filesystem's file_lock implementations because that can produce deadlocks. We used to make sure of this by only trusting that posix_lock_file() can correctly handle blocking lock calls asynchronously, so the lock managers would only setup their file_lock requests for async callbacks if the filesystem did not define its own lock() file operation However, when GFS2 and OCFS2 grew the capability to correctly handle blocking lock requests asynchronously, they started signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check for also trusting posix_lock_file() was inadvertently dropped, so now most filesystems no longer produce lock notifications when exported over NFS Fix this by using an fop_flag which greatly simplifies the problem and grooms the way for future uses by both filesystems and lock managers alike - Add a sysctl to delete the dentry when a file is removed instead of making it a negative dentry Commit 681ce8623567 ("vfs: Delete the associated dentry when deleting a file") introduced an unconditional deletion of the associated dentry when a file is removed. However, this led to performance regressions in specific benchmarks, such as ilebench.sum_operations/s, prompting a revert in commit 4a4be1ad3a6e ("Revert "vfs: Delete the associated dentry when deleting a file""). This reintroduces the concept conditionally through a sysctl - Expand the statmount() system call: * Report the filesystem subtype in a new fs_subtype field to e.g., report fuse filesystem subtypes * Report the superblock source in a new sb_source field * Add a new way to return filesystem specific mount options in an option array that returns filesystem specific mount options separated by zero bytes and unescaped. This allows caller's to retrieve filesystem specific mount options and immediately pass them to e.g., fsconfig() without having to unescape or split them * Report security (LSM) specific mount options in a separate security option array. We don't lump them together with filesystem specific mount options as security mount options are generic and most users aren't interested in them The format is the same as for the filesystem specific mount option array - Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command - Optimize acl_permission_check() to avoid costly {g,u}id ownership checks if possible - Use smp_mb__after_spinlock() to avoid full smp_mb() in evict() - Add synchronous wakeup support for ep_poll_callback. Currently, epoll only uses wake_up() to wake up task. But sometimes there are epoll users which want to use the synchronous wakeup flag to give a hint to the scheduler, e.g., the Android binder driver. So add a wake_up_sync() define, and use wake_up_sync() when sync is true in ep_poll_callback() Fixes: - Fix kernel documentation for inode_insert5() and iget5_locked() - Annotate racy epoll check on file->f_ep - Make F_DUPFD_QUERY associative - Avoid filename buffer overrun in initramfs - Don't let statmount() return empty strings - Add a cond_resched() to dump_user_range() to avoid hogging the CPU - Don't query the device logical blocksize multiple times for hfsplus - Make filemap_read() check that the offset is positive or zero Cleanups: - Various typo fixes - Cleanup wbc_attach_fdatawrite_inode() - Add __releases annotation to wbc_attach_and_unlock_inode() - Add hugetlbfs tracepoints - Fix various vfs kernel doc parameters - Remove obsolete TODO comment from io_cancel() - Convert wbc_account_cgroup_owner() to take a folio - Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add() - Reorder struct posix_acl to save 8 bytes - Annotate struct posix_acl with __counted_by() - Replace one-element array with flexible array member in freevxfs - Use idiomatic atomic64_inc_return() in alloc_mnt_ns()" * tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits) statmount: retrieve security mount options vfs: make evict() use smp_mb__after_spinlock instead of smp_mb statmount: add flag to retrieve unescaped options fs: add the ability for statmount() to report the sb_source writeback: wbc_attach_fdatawrite_inode out of line writeback: add a __releases annoation to wbc_attach_and_unlock_inode fs: add the ability for statmount() to report the fs_subtype fs: don't let statmount return empty strings fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel() hfsplus: don't query the device logical block size multiple times freevxfs: Replace one-element array with flexible array member fs: optimize acl_permission_check() initramfs: avoid filename buffer overrun fs/writeback: convert wbc_account_cgroup_owner to take a folio acl: Annotate struct posix_acl with __counted_by() acl: Realign struct posix_acl to save 8 bytes epoll: Add synchronous wakeup support for ep_poll_callback coredump: add cond_resched() to dump_user_range mm/page-writeback.c: Fix comment of wb_domain_writeout_add() mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL ...
2024-11-18Merge tag 'vfs-6.13.mgtime' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs multigrain timestamps from Christian Brauner: "This is another try at implementing multigrain timestamps. This time with significant help from the timekeeping maintainers to reduce the performance impact. Thomas provided a base branch that contains the required timekeeping interfaces for the VFS. It serves as the base for the multi-grain timestamp work: - Multigrain timestamps allow the kernel to use fine-grained timestamps when an inode's attributes is being actively observed via ->getattr(). With this support, it's possible for a file to get a fine-grained timestamp, and another modified after it to get a coarse-grained stamp that is earlier than the fine-grained time. If this happens then the files can appear to have been modified in reverse order, which breaks VFS ordering guarantees. To prevent this, a floor value is maintained for multigrain timestamps. Whenever a fine-grained timestamp is handed out, record it, and when later coarse-grained stamps are handed out, ensure they are not earlier than that value. If the coarse-grained timestamp is earlier than the fine-grained floor, return the floor value instead. The timekeeper changes add a static singleton atomic64_t into timekeeper.c that is used to keep track of the latest fine-grained time ever handed out. This is tracked as a monotonic ktime_t value to ensure that it isn't affected by clock jumps. Because it is updated at different times than the rest of the timekeeper object, the floor value is managed independently of the timekeeper via a cmpxchg() operation, and sits on its own cacheline. Two new public timekeeper interfaces are added: (1) ktime_get_coarse_real_ts64_mg() fills a timespec64 with the later of the coarse-grained clock and the floor time (2) ktime_get_real_ts64_mg() gets the fine-grained clock value, and tries to swap it into the floor. A timespec64 is filled with the result. - The VFS has always used coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide when to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This adds a way to only use fine-grained timestamps when they are being actively queried. Use the (unused) top bit in inode->i_ctime_nsec as a flag that indicates whether the current timestamps have been queried via stat() or the like. When it's set, we allow the kernel to use a fine-grained timestamp iff it's necessary to make the ctime show a different value. This solves the problem of being able to distinguish the timestamp between updates, but introduces a new problem: it's now possible for a file being changed to get a fine-grained timestamp. A file that is altered just a bit later can then get a coarse-grained one that appears older than the earlier fine-grained time. This violates timestamp ordering guarantees. This is where the earlier mentioned timkeeping interfaces help. A global monotonic atomic64_t value is kept that acts as a timestamp floor. When we go to stamp a file, we first get the latter of the current floor value and the current coarse-grained time. If the inode ctime hasn't been queried then we just attempt to stamp it with that value. If it has been queried, then first see whether the current coarse time is later than the existing ctime. If it is, then we accept that value. If it isn't, then we get a fine-grained time and try to swap that into the global floor. Whether that succeeds or fails, we take the resulting floor time, convert it to realtime and try to swap that into the ctime. We take the result of the ctime swap whether it succeeds or fails, since either is just as valid. Filesystems can opt into this by setting the FS_MGTIME fstype flag. Others should be unaffected (other than being subject to the same floor value as multigrain filesystems)" * tag 'vfs-6.13.mgtime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: reduce pointer chasing in is_mgtime() test tmpfs: add support for multigrain timestamps btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps Documentation: add a new file documenting multigrain timestamps fs: add percpu counters for significant multigrain timestamp events fs: tracepoints around multigrain timestamp events fs: handle delegated timestamps in setattr_copy_mgtime timekeeping: Add percpu counter for tracking floor swap events timekeeping: Add interfaces for handling timestamps with a floor value fs: have setattr_copy handle multigrain timestamps appropriately fs: add infrastructure for multigrain timestamps
2024-11-15Merge tag 'for-6.12-rc7-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One more fix that seems urgent and good to have in 6.12 final. It could potentially lead to unexpected transaction aborts, due to wrong comparison and order of processing of delayed refs" * tag 'for-6.12-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix incorrect comparison for delayed refs
2024-11-14btrfs: fix incorrect comparison for delayed refsJosef Bacik
When I reworked delayed ref comparison in cf4f04325b2b ("btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node"), I made a mistake and returned -1 for the case where ref1->ref_root was > than ref2->ref_root. This is a subtle bug that can result in improper delayed ref running order, which can result in transaction aborts. Fixes: cf4f04325b2b ("btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node") CC: stable@vger.kernel.org # 6.10+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-13btrfs: validate queue limitsChristoph Hellwig
Call blk_validate_limits on the queue limits used for zone append splitting so that calculated values get filled in and any stacking conflicts get cought. Without this there isn't a max_zone_append_sectors limits as of commit 559218d43ec9 ("block: pre-calculate max_zone_append_sectors"). Fixes: 559218d43ec9 ("block: pre-calculate max_zone_append_sectors") Reported-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241113084541.34315-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-11btrfs: send: check for read-only send root under critical sectionFilipe Manana
We're checking if the send root is read-only without being under the protection of the root's root_item_lock spinlock, which is what protects the root's flags when clearing the read-only flag, done at btrfs_ioctl_subvol_setflags(). Furthermore, it should be done in the same critical section that increments the root's send_in_progress counter, as btrfs_ioctl_subvol_setflags() clears the read-only flag in the same critical section that checks the counter's value. So fix this by moving the read-only check under the critical section delimited by the root's root_item_lock which also increments the root's send_in_progress counter. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: send: check for dead send root under critical sectionFilipe Manana
We're checking if the send root is dead without the protection of the root's root_item_lock spinlock, which is what protects the root's flags. The inverse, setting the dead flag on a root, is done under the protection of that lock, at btrfs_delete_subvolume(). Also checking and updating the root's send_in_progress counter is supposed to be done in the same critical section as checking for or setting the root dead flag, so that these operations are done atomically as a single step (which is correctly done by btrfs_delete_subvolume()). So fix this by checking if the send root is dead in the same critical section that updates the send_in_progress counter, which is protected by the root's root_item_lock spinlock. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap()Filipe Manana
Smatch complains about possibly dereferencing a NULL fs_info at btrfs_folio_end_lock_bitmap(): fs/btrfs/subpage.c:332 btrfs_folio_end_lock_bitmap() warn: variable dereferenced before check 'fs_info' (see line 326) because we access fs_info to set the 'start_bit' variable before doing the check for a NULL fs_info. However fs_info is never NULL, since in the only caller of btrfs_folio_end_lock_bitmap() is extent_writepage(), where we have an inode which always as a non-NULL fs_info. So remove the check for a NULL fs_info at btrfs_folio_end_lock_bitmap(). Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl()Filipe Manana
Smatch complains about calling PTR_ERR() against a NULL pointer: fs/btrfs/super.c:2272 btrfs_control_ioctl() warn: passing zero to 'PTR_ERR' Fix this by calling PTR_ERR() against the device pointer only if it contains an error. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: fix a typo in btrfs_use_zone_appendChristoph Hellwig
REQ_OP_ZONE_APPNED -> REQ_OP_ZONE_APPEND. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read()Mark Harmstone
Change the control flow of btrfs_encoded_read() so that it doesn't call free_extent_map() when we know that this has already been done. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Mark Harmstone <maharmstone@fb.com> Suggested-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot()Filipe Manana
There's no point in having a 'snapshot_force_cow' variable to track if we need to decrement the root->snapshot_force_cow counter, as we never jump to the 'out' label after incrementing the counter. Simplify this by removing the variable and always decrementing the counter before the 'out' label, right after the call to btrfs_mksubvol(). Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove hole from struct btrfs_delayed_nodeFilipe Manana
On x86_64 and a release kernel, there's a 4 bytes hole in the structure after the ref count field: struct btrfs_delayed_node { u64 inode_id; /* 0 8 */ u64 bytes_reserved; /* 8 8 */ struct btrfs_root * root; /* 16 8 */ struct list_head n_list; /* 24 16 */ struct list_head p_list; /* 40 16 */ struct rb_root_cached ins_root; /* 56 16 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ struct rb_root_cached del_root; /* 72 16 */ struct mutex mutex; /* 88 32 */ struct btrfs_inode_item inode_item; /* 120 160 */ /* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */ refcount_t refs; /* 280 4 */ /* XXX 4 bytes hole, try to pack */ u64 index_cnt; /* 288 8 */ long unsigned int flags; /* 296 8 */ int count; /* 304 4 */ u32 curr_index_batch_size; /* 308 4 */ u32 index_item_leaves; /* 312 4 */ /* size: 320, cachelines: 5, members: 15 */ /* sum members: 312, holes: 1, sum holes: 4 */ /* padding: 4 */ }; Move the 'count' field, which is 4 bytes long, to just below the ref count field, so we eliminate the hole and reduce the structure size from 320 bytes down to 312 bytes: struct btrfs_delayed_node { u64 inode_id; /* 0 8 */ u64 bytes_reserved; /* 8 8 */ struct btrfs_root * root; /* 16 8 */ struct list_head n_list; /* 24 16 */ struct list_head p_list; /* 40 16 */ struct rb_root_cached ins_root; /* 56 16 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ struct rb_root_cached del_root; /* 72 16 */ struct mutex mutex; /* 88 32 */ struct btrfs_inode_item inode_item; /* 120 160 */ /* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */ refcount_t refs; /* 280 4 */ int count; /* 284 4 */ u64 index_cnt; /* 288 8 */ long unsigned int flags; /* 296 8 */ u32 curr_index_batch_size; /* 304 4 */ u32 index_item_leaves; /* 308 4 */ /* size: 312, cachelines: 5, members: 15 */ /* last cacheline: 56 bytes */ }; This now allows to have 13 delayed nodes per 4K page instead of 12. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: update stale comment for struct btrfs_delayed_ref_node::add_listFilipe Manana
The comment refers to a list in the respective delayed ref head that no longer exists (ref_list), it was replaced with a rbtree (ref_tree) in commit 0e0adbcfdc90 ("btrfs: track refs in a rb_tree instead of a list"). So update the stale comment to refer to the rbtree instead of the old list. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: add new ioctl to wait for cleaned subvolumesDavid Sterba
Add a new unprivileged ioctl that will let the command 'btrfs subvolume sync' work without the (privileged) SEARCH_TREE ioctl. There are several modes of operation, where the most common ones are to wait on a specific subvolume or all currently queued for cleaning. This is utilized e.g. in backup applications that delete subvolumes and wait until they're cleaned to check for remaining space. The other modes are for flexibility, e.g. for monitoring or checkpoints in the queue of deleted subvolumes, again without the need to use SEARCH_TREE. Notes: - waiting is interruptible, the timeout is set to 1 second and is not configurable - repeated calls to the ioctl see a different state, so this is inherently racy when using e.g. the count or peek next/last Use cases: - a subvolume A was deleted, wait for cleaning (WAIT_FOR_ONE) - a bunch of subvolumes were deleted, wait for all (WAIT_FOR_QUEUED or PEEK_LAST + WAIT_FOR_ONE) - count how many are queued (not blocking), for monitoring purposes - report progress (PEEK_NEXT), may miss some if cleaning is quick - own waiting in user space (PEEK_LAST until it's 0) Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: simplify range tracking in cow_file_range()Haisu Wang
Simplify tracking of the range processed by using cur_alloc_size only to store the reserved part that may fail to the allocated extent. Remove the ram_size as well since it is always equal to cur_alloc_size in the context. Advance the start in normal path until extent allocation succeeds and keep the start unchanged in the error handling path. Passed the fstest generic/475 test for a hundred times with quota enabled. And a modified generic/475 test by removing the sleep time for a hundred times. About one tenth of the tests do enter the error handling path due to fail to reserve extent. Suggested-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Haisu Wang <haisuwang@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove conditional path allocation in btrfs_read_locked_inode()Leo Martins
Remove conditional path allocation from btrfs_read_locked_inode(). Add an ASSERT(path) to indicate it should never be called with a NULL path. Call btrfs_read_locked_inode() directly from btrfs_iget(). This causes code duplication between btrfs_iget() and btrfs_iget_path(), but I think this is justifiable as it removes the need for conditionally allocating the path inside of btrfs_read_locked_inode(). This makes the code easier to reason about and makes it clear who has the responsibility of allocating and freeing the path. Signed-off-by: Leo Martins <loemra.dev@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: push cleanup into btrfs_read_locked_inode()Leo Martins
Move btrfs_add_inode_to_root() so it can be called from btrfs_read_locked_inode(), no changes were made to the function. Move cleanup code from btrfs_iget_path() to btrfs_read_locked_inode. This improves readability and improves a leaky abstraction. Previously btrfs_iget_path() had to handle a positive error case as a result of a call to btrfs_search_slot(), but it makes more sense to handle this closer to the source of the call. Signed-off-by: Leo Martins <loemra.dev@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu()Mark Harmstone
Add struct io_btrfs_cmd as a wrapper type for io_uring_cmd_to_pdu(), rather than using a raw pointer. Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)Mark Harmstone
Add an io_uring command for encoded reads, using the same interface as the existing BTRFS_IOC_ENCODED_READ ioctl. btrfs_uring_encoded_read() is an io_uring version of btrfs_ioctl_encoded_read(), which validates the user input and calls btrfs_encoded_read() to read the appropriate metadata. If we determine that we need to read an extent from disk, we call btrfs_encoded_read_regular_fill_pages() through btrfs_uring_read_extent() to prepare the bio. The existing btrfs_encoded_read_regular_fill_pages() is changed so that if it is passed a valid uring_ctx, rather than waking up any waiting threads it calls btrfs_uring_read_extent_endio(). This in turn copies the read data back to userspace, and calls io_uring_cmd_done() to complete the io_uring command. Because we're potentially doing a non-blocking read, btrfs_uring_read_extent() doesn't clean up after itself if it returns -EIOCBQUEUED. Instead, it allocates a priv struct, populates the fields there that we will need to unlock the inode and free our allocations, and defers this to the btrfs_uring_read_finished() that gets called when the bio completes. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()Mark Harmstone
Change btrfs_encoded_read_regular_fill_pages() so that the priv struct is allocated rather than stored on the stack, in preparation for adding an asynchronous mode to the function. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is setMark Harmstone
Change btrfs_encoded_read() so that it returns -EAGAIN rather than sleeps if IOCB_NOWAIT is set in iocb->ki_flags. The conditions that require sleeping are: inode lock, writeback, extent lock, ordered range. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: change btrfs_encoded_read() so that reading of extent is done by callerMark Harmstone
Change the behaviour of btrfs_encoded_read() so that if it needs to read an extent from disk, it leaves the extent and inode locked and returns -EIOCBQUEUED. The caller is then responsible for doing the I/O via btrfs_encoded_read_regular() and unlocking the extent and inode. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read()Mark Harmstone
iocb->ki_pos isn't used after this function, so there's no point in changing its value. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove no longer used delayed ref head search functionalityFilipe Manana
After the previous patch, which converted the rb-tree used to track delayed ref heads into an xarray, the find_ref_head() function is now used only by one caller which always passes false to the 'return_bigger' argument. So remove the 'return_bigger' logic, simplifying the function, and move all the function code to the single caller. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: track delayed ref heads in an xarrayFilipe Manana
Currently we use a red black tree (rb-tree) to track the delayed ref heads (in struct btrfs_delayed_ref_root::href_root). This however is not very efficient when the number of delayed ref heads is large (and it's very common to be at least in the order of thousands) since rb-trees are binary trees. For example for 10K delayed ref heads, the tree has a depth of 13. Besides that, inserting into the tree requires navigating through it and pulling useless cache lines in the process since the red black tree nodes are embedded within the delayed ref head structure - on the other hand, by being embedded, it requires no extra memory allocations. We can improve this by using an xarray instead which has a much higher branching factor than a red black tree (binary balanced tree) and is more cache friendly and behaves like a resizable array, with a much better search and insertion complexity than a red black tree. This only has one small disadvantage which is that insertion will sometimes require allocating memory for the xarray - which may fail (not that often since it uses a kmem_cache) - but on the other hand we can reduce the delayed ref head structure size by 24 bytes (from 152 down to 128 bytes) after removing the embedded red black tree node, meaning than we can now fit 32 delayed ref heads per 4K page instead of 26, and that gain compensates for the occasional memory allocations needed for the xarray nodes. We also end up using only 2 cache lines instead of 3 per delayed ref head. Running the following fs_mark test showed some improvements: $ cat test.sh #!/bin/bash DEV=/dev/nullb0 MNT=/mnt/nullb0 MOUNT_OPTIONS="-o ssd" FILES=100000 THREADS=$(nproc --all) echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor mkfs.btrfs -f $DEV mount $MOUNT_OPTIONS $DEV $MNT OPTS="-S 0 -L 5 -n $FILES -s 0 -t $THREADS -k" for ((i = 1; i <= $THREADS; i++)); do OPTS="$OPTS -d $MNT/d$i" done fs_mark $OPTS umount $MNT Before this patch: FSUse% Count Size Files/sec App Overhead 10 1200000 0 171845.7 12253839 16 2400000 0 230898.7 12308254 23 3600000 0 212292.9 12467768 30 4800000 0 195737.8 12627554 46 6000000 0 171055.2 12783329 After this patch: FSUse% Count Size Files/sec App Overhead 10 1200000 0 173835.0 12246131 16 2400000 0 233537.8 12271746 23 3600000 0 220398.7 12307737 30 4800000 0 204483.6 12392318 40 6000000 0 182923.3 12771843 Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: add comments regarding locking to struct btrfs_delayed_ref_rootFilipe Manana
Add some comments to struct btrfs_delayed_ref_root's fields to mention what its spinlock protects. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: assert delayed refs lock is held at add_delayed_ref_head()Filipe Manana
The delayed refs lock must be held when calling add_delayed_ref_head(), so assert that it's being held. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: assert delayed refs lock is held at find_first_ref_head()Filipe Manana
The delayed refs lock must be held when calling find_first_ref_head(), so assert that it's being held. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: assert delayed refs lock is held at find_ref_head()Filipe Manana
We have 3 callers for find_ref_head() so assert at find_ref_head() that we have the delayed refs lock held, removing the assertion from one of its callers (btrfs_find_delayed_ref_head()). Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: pass fs_info to btrfs_delete_ref_head()Filipe Manana
One of the following patches in the series will need to access fs_info at btrfs_delete_ref_head(), so pass a fs_info argument to it. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: pass fs_info to functions that search for delayed ref headsFilipe Manana
One of the following patches in the series will need to access fs_info in the function find_ref_head(), so pass a fs_info argument to it as well as to the functions btrfs_select_ref_head() and btrfs_find_delayed_ref_head() which call find_ref_head(). Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: move delayed ref head unselection to delayed-ref.cFilipe Manana
The unselect_delayed_ref_head() at extent-tree.c doesn't really belong in that file as it's a delayed refs specific detail and therefore should be at delayed-ref.c. Further its inverse, btrfs_select_ref_head(), is at delayed-ref.c, so it only makes sense to have it there too. So move unselect_delayed_ref_head() into delayed-ref.c and rename it to btrfs_unselect_ref_head() so that its name closely matches its inverse (btrfs_select_ref_head()). Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: simplify obtaining a delayed ref headFilipe Manana
Instead of doing it in two steps outside of delayed-ref.c, leaking low level details such as locking, move the logic entirely to delayed-ref.c under btrfs_select_ref_head(), reducing code and making things simpler for the caller. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: change return type of btrfs_delayed_ref_lock() to booleanFilipe Manana
The function only returns 0, meaning it was able to lock the delayed ref head, or -EAGAIN in case it wasn't able to lock it. So simplify this and use a boolean return type instead, returning true if it was able to lock and false otherwise. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove num_entries atomic counter from delayed ref rootFilipe Manana
The atomic counter 'num_entries' is not used anymore, we increment it and decrement it but then we don't ever read it to use for any logic. Its last use was removed with commit 61a56a992fcf ("btrfs: delayed refs pre-flushing should only run the heads we have"). So remove it. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: use helper to find first ref head at btrfs_destroy_delayed_refs()Filipe Manana
Instead of open coding it, use the find_first_ref_head() helper at btrfs_destroy_delayed_refs(). This avoids duplicating the logic, specially with the upcoming changes in subsequent patches. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>