From d1825752e3074b5ff8d7f6016160e2b7c5c367ca Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 13 Jun 2024 11:16:19 +0100 Subject: [PATCH 1/4] btrfs: use NOFS context when getting inodes during logging and log replay During inode logging (and log replay too), we are holding a transaction handle and we often need to call btrfs_iget(), which will read an inode from its subvolume btree if it's not loaded in memory and that results in allocating an inode with GFP_KERNEL semantics at the btrfs_alloc_inode() callback - and this may recurse into the filesystem in case we are under memory pressure and attempt to commit the current transaction, resulting in a deadlock since the logging (or log replay) task is holding a transaction handle open. Syzbot reported this with the following stack traces: WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Not tainted ------------------------------------------------------ syz-executor.1/9919 is trying to acquire lock: ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 but task is already holding lock: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ei->log_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 btrfs_log_inode_parent+0x8cb/0x2a90 fs/btrfs/tree-log.c:7079 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315 start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700 btrfs_commit_super+0xa1/0x110 fs/btrfs/disk-io.c:4170 close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324 generic_shutdown_super+0x159/0x3d0 fs/super.c:642 kill_anon_super+0x3a/0x60 fs/super.c:1226 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #1 (btrfs_trans_num_writers){++++}-{0:0}: __lock_release kernel/locking/lockdep.c:5468 [inline] lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774 percpu_up_read include/linux/percpu-rwsem.h:99 [inline] __sb_end_write include/linux/fs.h:1650 [inline] sb_end_intwrite include/linux/fs.h:1767 [inline] __btrfs_end_transaction+0x5ca/0x920 fs/btrfs/transaction.c:1071 btrfs_commit_inode_delayed_inode+0x228/0x330 fs/btrfs/delayed-inode.c:1301 btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291 evict+0x2ed/0x6c0 fs/inode.c:667 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132 ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182 destroy_inode+0xc4/0x1b0 fs/inode.c:311 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 shrink_kill fs/dcache.c:1048 [inline] shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156 super_cache_scan+0x32a/0x550 fs/super.c:221 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa87/0x1310 mm/shrinker.c:626 shrink_one+0x493/0x7c0 mm/vmscan.c:4790 shrink_many mm/vmscan.c:4851 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951 shrink_node mm/vmscan.c:5910 [inline] kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: fs_reclaim --> btrfs_trans_num_extwriters --> &ei->log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->log_mutex); lock(btrfs_trans_num_extwriters); lock(&ei->log_mutex); lock(fs_reclaim); *** DEADLOCK *** 7 locks held by syz-executor.1/9919: #0: ffff88802be20420 (sb_writers#23){.+.+}-{0:0}, at: do_pwritev+0x1b2/0x260 fs/read_write.c:1072 #1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline] #1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: btrfs_inode_lock+0xc8/0x110 fs/btrfs/inode.c:385 #2: ffff888065c0f778 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_inode_lock+0xee/0x110 fs/btrfs/inode.c:388 #3: ffff88802be20610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_sync_file+0x95b/0xe10 fs/btrfs/file.c:1952 #4: ffff8880546323f0 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 #5: ffff888054632418 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 #6: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 stack backtrace: CPU: 2 PID: 9919 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7334579 Code: b8 01 10 06 03 (...) RSP: 002b:00000000f5f265ac EFLAGS: 00000292 ORIG_RAX: 000000000000017b RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000200002c0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fix this by ensuring we are under a NOFS scope whenever we call btrfs_iget() during inode logging and log replay. Reported-by: syzbot+8576cfa84070dce4d59b@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000274a3a061abbd928@google.com/ Fixes: 712e36c5f2a7 ("btrfs: use GFP_KERNEL in btrfs_alloc_inode") Reviewed-by: Johannes Thumshirn Reviewed-by: Josef Bacik Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/tree-log.c | 43 ++++++++++++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 26a2e5aa08e9..0bce1d45e252 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -138,6 +138,25 @@ static void wait_log_commit(struct btrfs_root *root, int transid); * and once to do all the other items. */ +static struct inode *btrfs_iget_logging(u64 objectid, struct btrfs_root *root) +{ + unsigned int nofs_flag; + struct inode *inode; + + /* + * We're holding a transaction handle whether we are logging or + * replaying a log tree, so we must make sure NOFS semantics apply + * because btrfs_alloc_inode() may be triggered and it uses GFP_KERNEL + * to allocate an inode, which can recurse back into the filesystem and + * attempt a transaction commit, resulting in a deadlock. + */ + nofs_flag = memalloc_nofs_save(); + inode = btrfs_iget(root->fs_info->sb, objectid, root); + memalloc_nofs_restore(nofs_flag); + + return inode; +} + /* * start a sub transaction and setup the log tree * this increments the log tree writer count to make the people @@ -600,7 +619,7 @@ static noinline struct inode *read_one_inode(struct btrfs_root *root, { struct inode *inode; - inode = btrfs_iget(root->fs_info->sb, objectid, root); + inode = btrfs_iget_logging(objectid, root); if (IS_ERR(inode)) inode = NULL; return inode; @@ -5438,7 +5457,6 @@ static int log_new_dir_dentries(struct btrfs_trans_handle *trans, struct btrfs_log_ctx *ctx) { struct btrfs_root *root = start_inode->root; - struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_path *path; LIST_HEAD(dir_list); struct btrfs_dir_list *dir_elem; @@ -5499,7 +5517,7 @@ again: continue; btrfs_release_path(path); - di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root); + di_inode = btrfs_iget_logging(di_key.objectid, root); if (IS_ERR(di_inode)) { ret = PTR_ERR(di_inode); goto out; @@ -5559,7 +5577,7 @@ again: btrfs_add_delayed_iput(curr_inode); curr_inode = NULL; - vfs_inode = btrfs_iget(fs_info->sb, ino, root); + vfs_inode = btrfs_iget_logging(ino, root); if (IS_ERR(vfs_inode)) { ret = PTR_ERR(vfs_inode); break; @@ -5654,7 +5672,7 @@ static int add_conflicting_inode(struct btrfs_trans_handle *trans, if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES) return BTRFS_LOG_FORCE_COMMIT; - inode = btrfs_iget(root->fs_info->sb, ino, root); + inode = btrfs_iget_logging(ino, root); /* * If the other inode that had a conflicting dir entry was deleted in * the current transaction then we either: @@ -5755,7 +5773,6 @@ static int log_conflicting_inodes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_log_ctx *ctx) { - struct btrfs_fs_info *fs_info = root->fs_info; int ret = 0; /* @@ -5786,7 +5803,7 @@ static int log_conflicting_inodes(struct btrfs_trans_handle *trans, list_del(&curr->list); kfree(curr); - inode = btrfs_iget(fs_info->sb, ino, root); + inode = btrfs_iget_logging(ino, root); /* * If the other inode that had a conflicting dir entry was * deleted in the current transaction, we need to log its parent @@ -5797,7 +5814,7 @@ static int log_conflicting_inodes(struct btrfs_trans_handle *trans, if (ret != -ENOENT) break; - inode = btrfs_iget(fs_info->sb, parent, root); + inode = btrfs_iget_logging(parent, root); if (IS_ERR(inode)) { ret = PTR_ERR(inode); break; @@ -6319,7 +6336,6 @@ static int log_new_delayed_dentries(struct btrfs_trans_handle *trans, struct btrfs_log_ctx *ctx) { const bool orig_log_new_dentries = ctx->log_new_dentries; - struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_item *item; int ret = 0; @@ -6345,7 +6361,7 @@ static int log_new_delayed_dentries(struct btrfs_trans_handle *trans, if (key.type == BTRFS_ROOT_ITEM_KEY) continue; - di_inode = btrfs_iget(fs_info->sb, key.objectid, inode->root); + di_inode = btrfs_iget_logging(key.objectid, inode->root); if (IS_ERR(di_inode)) { ret = PTR_ERR(di_inode); break; @@ -6729,7 +6745,6 @@ static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, struct btrfs_inode *inode, struct btrfs_log_ctx *ctx) { - struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_path *path; struct btrfs_key key; @@ -6794,8 +6809,7 @@ static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, cur_offset = item_size; } - dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid, - root); + dir_inode = btrfs_iget_logging(inode_key.objectid, root); /* * If the parent inode was deleted, return an error to * fallback to a transaction commit. This is to prevent @@ -6857,7 +6871,6 @@ static int log_new_ancestors(struct btrfs_trans_handle *trans, btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); while (true) { - struct btrfs_fs_info *fs_info = root->fs_info; struct extent_buffer *leaf; int slot; struct btrfs_key search_key; @@ -6872,7 +6885,7 @@ static int log_new_ancestors(struct btrfs_trans_handle *trans, search_key.objectid = found_key.offset; search_key.type = BTRFS_INODE_ITEM_KEY; search_key.offset = 0; - inode = btrfs_iget(fs_info->sb, ino, root); + inode = btrfs_iget_logging(ino, root); if (IS_ERR(inode)) return PTR_ERR(inode); From b9fd2affe4aa99a4ca14ee87e1f38fea22ece52a Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Tue, 11 Jun 2024 17:17:30 +0900 Subject: [PATCH 2/4] btrfs: zoned: fix initial free space detection When creating a new block group, it calls btrfs_add_new_free_space() to add the entire block group range into the free space accounting. __btrfs_add_free_space_zoned() checks if size == block_group->length to detect the initial free space adding, and proceed that case properly. However, if the zone_capacity == zone_size and the over-write speed is fast enough, the entire zone can be over-written within one transaction. That confuses __btrfs_add_free_space_zoned() to handle it as an initial free space accounting. As a result, that block group becomes a strange state: 0 used bytes, 0 zone_unusable bytes, but alloc_offset == zone_capacity (no allocation anymore). The initial free space accounting can properly be checked by checking alloc_offset too. Fixes: 98173255bddd ("btrfs: zoned: calculate free space from zone capacity") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Johannes Thumshirn Signed-off-by: Naohiro Aota Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/free-space-cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index c8a05d5eb9cb..b642df5e5255 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -2697,7 +2697,7 @@ static int __btrfs_add_free_space_zoned(struct btrfs_block_group *block_group, u64 offset = bytenr - block_group->start; u64 to_free, to_unusable; int bg_reclaim_threshold = 0; - bool initial = (size == block_group->length); + bool initial = ((size == block_group->length) && (block_group->alloc_offset == 0)); u64 reclaimable_unusable; WARN_ON(!initial && offset + size > block_group->zone_capacity); From 2c49908634a2b97b1c3abe0589be2739ac5e7fd5 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 17 Jun 2024 15:18:44 +0930 Subject: [PATCH 3/4] btrfs: scrub: handle RST lookup error correctly [BUG] When running btrfs/060 with forced RST feature, it would crash the following ASSERT() inside scrub_read_endio(): ASSERT(sector_nr < stripe->nr_sectors); Before that, we would have tree dump from btrfs_get_raid_extent_offset(), as we failed to find the RST entry for the range. [CAUSE] Inside scrub_submit_extent_sector_read() every time we allocated a new bbio we immediately called btrfs_map_block() to make sure there was some RST range covering the scrub target. But if btrfs_map_block() fails, we immediately call endio for the bbio, while the bbio is newly allocated, it's completely empty. Then inside scrub_read_endio(), we go through the bvecs to find the sector number (as bi_sector is no longer reliable if the bio is submitted to lower layers). And since the bio is empty, such bvecs iteration would not find any sector matching the sector, and return sector_nr == stripe->nr_sectors, triggering the ASSERT(). [FIX] Instead of calling btrfs_map_block() after allocating a new bbio, call btrfs_map_block() first. Since our only objective of calling btrfs_map_block() is only to update stripe_len, there is really no need to do that after btrfs_alloc_bio(). This new timing would avoid the problem of handling empty bbio completely, and in fact fixes a possible race window for the old code, where if the submission thread is the only owner of the pending_io, the scrub would never finish (since we didn't decrease the pending_io counter). Although the root cause of RST lookup failure still needs to be addressed. Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/scrub.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index afd6932f5e89..d7caa3732f07 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -1688,20 +1688,24 @@ static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx, (i << fs_info->sectorsize_bits); int err; + io_stripe.is_scrub = true; + stripe_len = (nr_sectors - i) << fs_info->sectorsize_bits; + /* + * For RST cases, we need to manually split the bbio to + * follow the RST boundary. + */ + err = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical, + &stripe_len, &bioc, &io_stripe, &mirror); + btrfs_put_bioc(bioc); + if (err < 0) { + set_bit(i, &stripe->io_error_bitmap); + set_bit(i, &stripe->error_bitmap); + continue; + } + bbio = btrfs_bio_alloc(stripe->nr_sectors, REQ_OP_READ, fs_info, scrub_read_endio, stripe); bbio->bio.bi_iter.bi_sector = logical >> SECTOR_SHIFT; - - io_stripe.is_scrub = true; - err = btrfs_map_block(fs_info, BTRFS_MAP_READ, logical, - &stripe_len, &bioc, &io_stripe, - &mirror); - btrfs_put_bioc(bioc); - if (err) { - btrfs_bio_end_io(bbio, - errno_to_blk_status(err)); - return; - } } __bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff); From a7e4c6a3031c74078dba7fa36239d0f4fe476c53 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 20 Jun 2024 12:32:00 +0100 Subject: [PATCH 4/4] btrfs: qgroup: fix quota root leak after quota disable failure If during the quota disable we fail when cleaning the quota tree or when deleting the root from the root tree, we jump to the 'out' label without ever dropping the reference on the quota root, resulting in a leak of the root since fs_info->quota_root is no longer pointing to the root (we have set it to NULL just before those steps). Fix this by always doing a btrfs_put_root() call under the 'out' label. This is a problem that exists since qgroups were first added in 2012 by commit bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but back then we missed a kfree on the quota root and free_extent_buffer() calls on its root and commit root nodes, since back then roots were not yet reference counted. Reviewed-by: Boris Burkov Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/qgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index fc2a7ea26354..bf0f81d59b6b 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1351,7 +1351,7 @@ static int flush_reservations(struct btrfs_fs_info *fs_info) int btrfs_quota_disable(struct btrfs_fs_info *fs_info) { - struct btrfs_root *quota_root; + struct btrfs_root *quota_root = NULL; struct btrfs_trans_handle *trans = NULL; int ret = 0; @@ -1449,9 +1449,9 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info) btrfs_free_tree_block(trans, btrfs_root_id(quota_root), quota_root->node, 0, 1); - btrfs_put_root(quota_root); out: + btrfs_put_root(quota_root); mutex_unlock(&fs_info->qgroup_ioctl_lock); if (ret && trans) btrfs_end_transaction(trans);