From cf6ae7ed091059a8d1a70cf184f18ebfd18ab4af Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 26 Mar 2025 14:41:13 +1030 Subject: [PATCH 1/8] btrfs: subpage: access correct object when reading bitmap start in subpage_calc_start_bit() Inside the macro, subpage_calc_start_bit(), we need to calculate the offset to the beginning of the folio. But we're using offset_in_page(), on systems with 4K page size and 4K fs block size, this means we will always return offset 0 for a large folio, causing all kinds of errors. Fix it by using offset_in_folio() instead. Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/subpage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index 11dbd7be6a3b..bd252c78a261 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -204,7 +204,7 @@ static void btrfs_subpage_assert(const struct btrfs_fs_info *fs_info, btrfs_blocks_per_folio(fs_info, folio); \ \ btrfs_subpage_assert(fs_info, folio, start, len); \ - __start_bit = offset_in_page(start) >> fs_info->sectorsize_bits; \ + __start_bit = offset_in_folio(folio, start) >> fs_info->sectorsize_bits; \ __start_bit += blocks_per_folio * btrfs_bitmap_nr_##name; \ __start_bit; \ }) From bc2dbc4983afedd198490cca043798f57c93e9bf Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Sat, 29 Mar 2025 17:46:35 +1030 Subject: [PATCH 2/8] btrfs: avoid page_lockend underflow in btrfs_punch_hole_lock_range() [BUG] When running btrfs/004 with 4K fs block size and 64K page size, sometimes fsstress workload can take 100% CPU for a while, but not long enough to trigger a 120s hang warning. [CAUSE] When such 100% CPU usage happens, btrfs_punch_hole_lock_range() is always in the call trace. One example when this problem happens, the function btrfs_punch_hole_lock_range() got the following parameters: lock_start = 4096, lockend = 20469 Then we calculate @page_lockstart by rounding up lock_start to page boundary, which is 64K (page size is 64K). For @page_lockend, we round down the value towards page boundary, which result 0. Then since we need to pass an inclusive end to filemap_range_has_page(), we subtract 1 from the rounded down value, resulting in (u64)-1. In the above case, the range is inside the same page, and we do not even need to call filemap_range_has_page(), not to mention to call it with (u64)-1 at the end. This behavior will cause btrfs_punch_hole_lock_range() to busy loop waiting for irrelevant range to have its pages dropped. [FIX] Calculate @page_lockend by just rounding down @lockend, without decreasing the value by one. So @page_lockend will no longer overflow. Then exit early if @page_lockend is no larger than @page_lockstart. As it means either the range is inside the same page, or the two pages are adjacent already. Finally only decrease @page_lockend when calling filemap_range_has_page(). Fixes: 0528476b6ac7 ("btrfs: fix the filemap_range_has_page() call in btrfs_punch_hole_lock_range()") Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/file.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 262a707d8990..71b8a825c447 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2104,15 +2104,20 @@ static void btrfs_punch_hole_lock_range(struct inode *inode, * will always return true. * So here we need to do extra page alignment for * filemap_range_has_page(). + * + * And do not decrease page_lockend right now, as it can be 0. */ const u64 page_lockstart = round_up(lockstart, PAGE_SIZE); - const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1; + const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE); while (1) { truncate_pagecache_range(inode, lockstart, lockend); lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, cached_state); + /* The same page or adjacent pages. */ + if (page_lockend <= page_lockstart) + break; /* * We can't have ordered extents in the range, nor dirty/writeback * pages, because we have locked the inode's VFS lock in exclusive @@ -2124,7 +2129,7 @@ static void btrfs_punch_hole_lock_range(struct inode *inode, * we do, unlock the range and retry. */ if (!filemap_range_has_page(inode->i_mapping, page_lockstart, - page_lockend)) + page_lockend - 1)) break; unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, From 7d82240c457fc15abdf7dedf15104cea774b005b Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 1 Apr 2025 18:20:28 +1030 Subject: [PATCH 3/8] btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP() After enabling large data folios for tests, I hit the ASSERT() inside GET_SUBPAGE_BITMAP() where blocks_per_folio matches BITS_PER_LONG. The ASSERT() itself is only based on the original subpage fs block size, where we have at most 16 blocks per page, thus "ASSERT(blocks_per_folio < BITS_PER_LONG)". However the experimental large data folio support will set the max folio order according to the BITS_PER_LONG, so we can have a case where a large folio contains exactly BITS_PER_LONG blocks. So the ASSERT() is too strict, change it to "ASSERT(blocks_per_folio <= BITS_PER_LONG)" to avoid the false alert. Reviewed-by: Filipe Manana Reviewed-by: Sweet Tea Dorminy Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/subpage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index bd252c78a261..c0a0b8b063d0 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -666,7 +666,7 @@ IMPLEMENT_BTRFS_PAGE_OPS(checked, folio_set_checked, folio_clear_checked, btrfs_blocks_per_folio(fs_info, folio); \ const struct btrfs_subpage *subpage = folio_get_private(folio); \ \ - ASSERT(blocks_per_folio < BITS_PER_LONG); \ + ASSERT(blocks_per_folio <= BITS_PER_LONG); \ *dst = bitmap_read(subpage->bitmaps, \ blocks_per_folio * btrfs_bitmap_nr_##name, \ blocks_per_folio); \ From b0c26f47992672661340dd6ea931240213016609 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Mon, 17 Mar 2025 16:04:01 +0100 Subject: [PATCH 4/8] btrfs: zoned: return EIO on RAID1 block group write pointer mismatch MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There was a bug report about a NULL pointer dereference in __btrfs_add_free_space_zoned() that ultimately happens because a conversion from the default metadata profile DUP to a RAID1 profile on two disks. The stack trace has the following signature: BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile BUG: kernel NULL pointer dereference, address: 0000000000000058 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:__btrfs_add_free_space_zoned.isra.0+0x61/0x1a0 RSP: 0018:ffffa236b6f3f6d0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff96c8132f3400 RCX: 0000000000000001 RDX: 0000000010000000 RSI: 0000000000000000 RDI: ffff96c8132f3410 RBP: 0000000010000000 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000000 R13: ffff96c758f65a40 R14: 0000000000000001 R15: 000011aac0000000 FS: 00007fdab1cb2900(0000) GS:ffff96e60ca00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000058 CR3: 00000001a05ae000 CR4: 0000000000350ef0 Call Trace: ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15c/0x2f0 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? __btrfs_add_free_space_zoned.isra.0+0x61/0x1a0 btrfs_add_free_space_async_trimmed+0x34/0x40 btrfs_add_new_free_space+0x107/0x120 btrfs_make_block_group+0x104/0x2b0 btrfs_create_chunk+0x977/0xf20 btrfs_chunk_alloc+0x174/0x510 ? srso_return_thunk+0x5/0x5f btrfs_inc_block_group_ro+0x1b1/0x230 btrfs_relocate_block_group+0x9e/0x410 btrfs_relocate_chunk+0x3f/0x130 btrfs_balance+0x8ac/0x12b0 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? __kmalloc_cache_noprof+0x14c/0x3e0 btrfs_ioctl+0x2686/0x2a80 ? srso_return_thunk+0x5/0x5f ? ioctl_has_perm.constprop.0.isra.0+0xd2/0x120 __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x82/0x160 ? srso_return_thunk+0x5/0x5f ? __memcg_slab_free_hook+0x11a/0x170 ? srso_return_thunk+0x5/0x5f ? kmem_cache_free+0x3f0/0x450 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? syscall_exit_to_user_mode+0x10/0x210 ? srso_return_thunk+0x5/0x5f ? do_syscall_64+0x8e/0x160 ? sysfs_emit+0xaf/0xc0 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? seq_read_iter+0x207/0x460 ? srso_return_thunk+0x5/0x5f ? vfs_read+0x29c/0x370 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? syscall_exit_to_user_mode+0x10/0x210 ? srso_return_thunk+0x5/0x5f ? do_syscall_64+0x8e/0x160 ? srso_return_thunk+0x5/0x5f ? exc_page_fault+0x7e/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fdab1e0ca6d RSP: 002b:00007ffeb2b60c80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdab1e0ca6d RDX: 00007ffeb2b60d80 RSI: 00000000c4009420 RDI: 0000000000000003 RBP: 00007ffeb2b60cd0 R08: 0000000000000000 R09: 0000000000000013 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeb2b6343b R14: 00007ffeb2b60d80 R15: 0000000000000001 CR2: 0000000000000058 ---[ end trace 0000000000000000 ]--- The 1st line is the most interesting here: BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile When a RAID1 block-group is created and a write pointer mismatch between the disks in the RAID set is detected, btrfs sets the alloc_offset to the length of the block group marking it as full. Afterwards the code expects that a balance operation will evacuate the data in this block-group and repair the problems. But before this is possible, the new space of this block-group will be accounted in the free space cache. But in __btrfs_add_free_space_zoned() it is being checked if it is a initial creation of a block group and if not a reclaim decision will be made. But the decision if a block-group's free space accounting is done for an initial creation depends on if the size of the added free space is the whole length of the block-group and the allocation offset is 0. But as btrfs_load_block_group_zone_info() sets the allocation offset to the zone capacity (i.e. marking the block-group as full) this initial decision is not met, and the space_info pointer in the 'struct btrfs_block_group' has not yet been assigned. Fail creation of the block group and rely on manual user intervention to re-balance the filesystem. Afterwards the filesystem can be unmounted, mounted in degraded mode and the missing device can be removed after a full balance of the filesystem. Reported-by: 西木野羰基 Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/ Fixes: b1934cd60695 ("btrfs: zoned: handle broken write pointer on zones") Reviewed-by: Anand Jain Signed-off-by: Johannes Thumshirn Signed-off-by: David Sterba --- fs/btrfs/zoned.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index fb8b8b29c169..7c502192cd6b 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -1659,7 +1659,6 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new) * stripe. */ cache->alloc_offset = cache->zone_capacity; - ret = 0; } out: From 50fecb8cf069f0814642ce0bde965bdc1f35a79e Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Sat, 5 Apr 2025 18:40:14 +0100 Subject: [PATCH 5/8] btrfs: fix invalid inode pointer after failure to create reloc inode If we have a failure at create_reloc_inode(), under the 'out' label we assign an error pointer to the 'inode' variable and then return a weird pointer because we return the expression "&inode->vfs_inode": static noinline_for_stack struct inode *create_reloc_inode( const struct btrfs_block_group *group) { (...) out: (...) if (ret) { if (inode) iput(&inode->vfs_inode); inode = ERR_PTR(ret); } return &inode->vfs_inode; } This can make us return a pointer that is not an error pointer and make the caller proceed as if an error didn't happen and later result in an invalid memory access when dereferencing the inode pointer. Syzbot reported reported such a case with the following stack trace: R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790 BTRFS info (device loop0): relocating block group 6881280 flags data|metadata Oops: general protection fault, probably for non-canonical address 0xdffffc0000000045: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000228-0x000000000000022f] CPU: 0 UID: 0 PID: 5332 Comm: syz-executor215 Not tainted 6.14.0-syzkaller-13423-ga8662bcd2ff1 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971 Code: 00 74 08 (...) RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203 RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000 RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000 FS: 000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: relocate_block_group+0xa1e/0xd50 fs/btrfs/relocation.c:3657 btrfs_relocate_block_group+0x777/0xd80 fs/btrfs/relocation.c:4011 btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3511 __btrfs_balance+0x1a93/0x25e0 fs/btrfs/volumes.c:4292 btrfs_balance+0xbde/0x10c0 fs/btrfs/volumes.c:4669 btrfs_ioctl_balance+0x3f5/0x660 fs/btrfs/ioctl.c:3586 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb4ef537dd9 Code: 28 00 00 (...) RSP: 002b:00007ffc55de5728 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffc55de5750 RCX: 00007fb4ef537dd9 RDX: 0000200000000440 RSI: 00000000c4009420 RDI: 0000000000000003 RBP: 0000000000000002 R08: 00007ffc55de54c6 R09: 00007ffc55de5770 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffc55de5790 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971 Code: 00 74 08 (...) RSP: 0018:ffffc9000d3375e0 EFLAGS: 00010203 RAX: 0000000000000045 RBX: 000000000000022c RCX: ffff888000562440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880452db000 RBP: ffffc9000d337870 R08: ffffffff84089251 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff9368a020 R14: 0000000000000394 R15: ffff8880452db000 FS: 000055558bc7b380(0000) GS:ffff88808c596000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a7a192e740 CR3: 0000000036e2e000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 00 74 08 48 add %dh,0x48(%rax,%rcx,1) 4: 89 df mov %ebx,%edi 6: e8 f8 36 24 fe call 0xfe243703 b: 48 89 9c 24 30 01 00 mov %rbx,0x130(%rsp) 12: 00 13: 4c 89 74 24 28 mov %r14,0x28(%rsp) 18: 4d 8b 76 10 mov 0x10(%r14),%r14 1c: 49 8d 9e 98 fe ff ff lea -0x168(%r14),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 ca 36 24 fe call 0xfe243703 39: 4c 8b 3b mov (%rbx),%r15 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 44 rex.R 3f: 24 .byte 0x24 So fix this by returning the error immediately. Reported-by: syzbot+7481815bb47ef3e702e2@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/67f14ee9.050a0220.0a13.023e.GAE@google.com/ Fixes: b204e5c7d4dc ("btrfs: make btrfs_iget() return a btrfs inode instead") Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Signed-off-by: David Sterba --- fs/btrfs/relocation.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index f948f4f6431c..e17bcb034595 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3803,7 +3803,7 @@ static noinline_for_stack struct inode *create_reloc_inode( if (ret) { if (inode) iput(&inode->vfs_inode); - inode = ERR_PTR(ret); + return ERR_PTR(ret); } return &inode->vfs_inode; } From f1ab0171e9be96fd530329fa54761cff5e09ea95 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 4 Apr 2025 20:19:41 +0200 Subject: [PATCH 6/8] btrfs: tree-checker: adjust error code for header level check The whole tree checker returns EUCLEAN, except the one check in btrfs_verify_level_key(). This was inherited from the function that was moved from disk-io.c in 2cac5af16537 ("btrfs: move btrfs_verify_level_key into tree-checker.c") but this should be unified with the rest. Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/tree-checker.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 43979891f7c8..2b66a6130269 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -2235,7 +2235,7 @@ int btrfs_verify_level_key(struct extent_buffer *eb, btrfs_err(fs_info, "tree level mismatch detected, bytenr=%llu level expected=%u has=%u", eb->start, check->level, found_level); - return -EIO; + return -EUCLEAN; } if (!check->has_first_key) From c1a79b1a583654f24b17da81ba868b0064077243 Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Wed, 19 Mar 2025 10:49:16 +0900 Subject: [PATCH 7/8] block: introduce zone capacity helper {bdev,disk}_zone_capacity() takes block_device or gendisk and sector position and returns the zone capacity of the corresponding zone. With that, move disk_nr_zones() and blk_zone_plug_bio() to consolidate them in the same #ifdef block. Signed-off-by: Naohiro Aota Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Signed-off-by: David Sterba --- include/linux/blkdev.h | 67 ++++++++++++++++++++++++++++-------------- 1 file changed, 45 insertions(+), 22 deletions(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d37751789bf5..c57babb0adb9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -691,23 +691,6 @@ static inline bool blk_queue_is_zoned(struct request_queue *q) (q->limits.features & BLK_FEAT_ZONED); } -#ifdef CONFIG_BLK_DEV_ZONED -static inline unsigned int disk_nr_zones(struct gendisk *disk) -{ - return disk->nr_zones; -} -bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs); -#else /* CONFIG_BLK_DEV_ZONED */ -static inline unsigned int disk_nr_zones(struct gendisk *disk) -{ - return 0; -} -static inline bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) -{ - return false; -} -#endif /* CONFIG_BLK_DEV_ZONED */ - static inline unsigned int disk_zone_no(struct gendisk *disk, sector_t sector) { if (!blk_queue_is_zoned(disk->queue)) @@ -715,11 +698,6 @@ static inline unsigned int disk_zone_no(struct gendisk *disk, sector_t sector) return sector >> ilog2(disk->queue->limits.chunk_sectors); } -static inline unsigned int bdev_nr_zones(struct block_device *bdev) -{ - return disk_nr_zones(bdev->bd_disk); -} - static inline unsigned int bdev_max_open_zones(struct block_device *bdev) { return bdev->bd_disk->queue->limits.max_open_zones; @@ -826,6 +804,51 @@ static inline u64 sb_bdev_nr_blocks(struct super_block *sb) (sb->s_blocksize_bits - SECTOR_SHIFT); } +#ifdef CONFIG_BLK_DEV_ZONED +static inline unsigned int disk_nr_zones(struct gendisk *disk) +{ + return disk->nr_zones; +} +bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs); + +/** + * disk_zone_capacity - returns the zone capacity of zone containing @sector + * @disk: disk to work with + * @sector: sector number within the querying zone + * + * Returns the zone capacity of a zone containing @sector. @sector can be any + * sector in the zone. + */ +static inline unsigned int disk_zone_capacity(struct gendisk *disk, + sector_t sector) +{ + sector_t zone_sectors = disk->queue->limits.chunk_sectors; + + if (sector + zone_sectors >= get_capacity(disk)) + return disk->last_zone_capacity; + return disk->zone_capacity; +} +static inline unsigned int bdev_zone_capacity(struct block_device *bdev, + sector_t pos) +{ + return disk_zone_capacity(bdev->bd_disk, pos); +} +#else /* CONFIG_BLK_DEV_ZONED */ +static inline unsigned int disk_nr_zones(struct gendisk *disk) +{ + return 0; +} +static inline bool blk_zone_plug_bio(struct bio *bio, unsigned int nr_segs) +{ + return false; +} +#endif /* CONFIG_BLK_DEV_ZONED */ + +static inline unsigned int bdev_nr_zones(struct block_device *bdev) +{ + return disk_nr_zones(bdev->bd_disk); +} + int bdev_disk_changed(struct gendisk *disk, bool invalidate); void put_disk(struct gendisk *disk); From 866bafae59ecffcf1840d846cd79740be29f21d6 Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Wed, 19 Mar 2025 10:49:17 +0900 Subject: [PATCH 8/8] btrfs: zoned: skip reporting zone for new block group There is a potential deadlock if we do report zones in an IO context, detailed in below lockdep report. When one process do a report zones and another process freezes the block device, the report zones side cannot allocate a tag because the freeze is already started. This can thus result in new block group creation to hang forever, blocking the write path. Thankfully, a new block group should be created on empty zones. So, reporting the zones is not necessary and we can set the write pointer = 0 and load the zone capacity from the block layer using bdev_zone_capacity() helper. ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc1 #252 Not tainted ------------------------------------------------------ modprobe/1110 is trying to acquire lock: ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60 but task is already holding lock: ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&q->q_usage_counter(queue)#16){++++}-{0:0}: blk_queue_enter+0x3d9/0x500 blk_mq_alloc_request+0x47d/0x8e0 scsi_execute_cmd+0x14f/0xb80 sd_zbc_do_report_zones+0x1c1/0x470 sd_zbc_report_zones+0x362/0xd60 blkdev_report_zones+0x1b1/0x2e0 btrfs_get_dev_zones+0x215/0x7e0 [btrfs] btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs] btrfs_make_block_group+0x36b/0x870 [btrfs] btrfs_create_chunk+0x147d/0x2320 [btrfs] btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs] start_transaction+0xce6/0x1620 [btrfs] btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs] kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #2 (&fs_info->dev_replace.rwsem){++++}-{4:4}: down_read+0x9b/0x470 btrfs_map_block+0x2ce/0x2ce0 [btrfs] btrfs_submit_chunk+0x2d4/0x16c0 [btrfs] btrfs_submit_bbio+0x16/0x30 [btrfs] btree_write_cache_pages+0xb5a/0xf90 [btrfs] do_writepages+0x17f/0x7b0 __writeback_single_inode+0x114/0xb00 writeback_sb_inodes+0x52b/0xe00 wb_writeback+0x1a7/0x800 wb_workfn+0x12a/0xbd0 process_one_work+0x85a/0x1460 worker_thread+0x5e2/0xfc0 kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}: __mutex_lock+0x1aa/0x1360 btree_write_cache_pages+0x252/0xf90 [btrfs] do_writepages+0x17f/0x7b0 __writeback_single_inode+0x114/0xb00 writeback_sb_inodes+0x52b/0xe00 wb_writeback+0x1a7/0x800 wb_workfn+0x12a/0xbd0 process_one_work+0x85a/0x1460 worker_thread+0x5e2/0xfc0 kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}: __lock_acquire+0x2f52/0x5ea0 lock_acquire+0x1b1/0x540 __flush_work+0x3ac/0xb60 wb_shutdown+0x15b/0x1f0 bdi_unregister+0x172/0x5b0 del_gendisk+0x841/0xa20 sd_remove+0x85/0x130 device_release_driver_internal+0x368/0x520 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 __scsi_remove_device+0x272/0x340 scsi_forget_host+0xf7/0x170 scsi_remove_host+0xd2/0x2a0 sdebug_driver_remove+0x52/0x2f0 [scsi_debug] device_release_driver_internal+0x368/0x520 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 device_unregister+0x13/0xa0 sdebug_do_remove_host+0x1fb/0x290 [scsi_debug] scsi_debug_exit+0x17/0x70 [scsi_debug] __do_sys_delete_module.isra.0+0x321/0x520 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: (work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)#16 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(queue)#16); lock(&fs_info->dev_replace.rwsem); lock(&q->q_usage_counter(queue)#16); lock((work_completion)(&(&wb->dwork)->work)); *** DEADLOCK *** 5 locks held by modprobe/1110: #0: ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520 #1: ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0 #2: ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520 #3: ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130 #4: ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60 stack backtrace: CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 #252 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: dump_stack_lvl+0x6a/0x90 print_circular_bug.cold+0x1e0/0x274 check_noncircular+0x306/0x3f0 ? __pfx_check_noncircular+0x10/0x10 ? mark_lock+0xf5/0x1650 ? __pfx_check_irq_usage+0x10/0x10 ? lockdep_lock+0xca/0x1c0 ? __pfx_lockdep_lock+0x10/0x10 __lock_acquire+0x2f52/0x5ea0 ? __pfx___lock_acquire+0x10/0x10 ? __pfx_mark_lock+0x10/0x10 lock_acquire+0x1b1/0x540 ? __flush_work+0x38f/0xb60 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? mark_held_locks+0x94/0xe0 ? __flush_work+0x38f/0xb60 __flush_work+0x3ac/0xb60 ? __flush_work+0x38f/0xb60 ? __pfx_mark_lock+0x10/0x10 ? __pfx___flush_work+0x10/0x10 ? __pfx_wq_barrier_func+0x10/0x10 ? __pfx___might_resched+0x10/0x10 ? mark_held_locks+0x94/0xe0 wb_shutdown+0x15b/0x1f0 bdi_unregister+0x172/0x5b0 ? __pfx_bdi_unregister+0x10/0x10 ? up_write+0x1ba/0x510 del_gendisk+0x841/0xa20 ? __pfx_del_gendisk+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x35/0x60 ? __pm_runtime_resume+0x79/0x110 sd_remove+0x85/0x130 device_release_driver_internal+0x368/0x520 ? kobject_put+0x5d/0x4a0 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 ? __pfx_device_del+0x10/0x10 __scsi_remove_device+0x272/0x340 scsi_forget_host+0xf7/0x170 scsi_remove_host+0xd2/0x2a0 sdebug_driver_remove+0x52/0x2f0 [scsi_debug] ? kernfs_remove_by_name_ns+0xc0/0xf0 device_release_driver_internal+0x368/0x520 ? kobject_put+0x5d/0x4a0 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 ? __pfx_device_del+0x10/0x10 ? __pfx___mutex_unlock_slowpath+0x10/0x10 device_unregister+0x13/0xa0 sdebug_do_remove_host+0x1fb/0x290 [scsi_debug] scsi_debug_exit+0x17/0x70 [scsi_debug] __do_sys_delete_module.isra.0+0x321/0x520 ? __pfx___do_sys_delete_module.isra.0+0x10/0x10 ? __pfx_slab_free_after_rcu_debug+0x10/0x10 ? kasan_save_stack+0x2c/0x50 ? kasan_record_aux_stack+0xa3/0xb0 ? __call_rcu_common.constprop.0+0xc4/0xfb0 ? kmem_cache_free+0x3a0/0x590 ? __x64_sys_close+0x78/0xd0 do_syscall_64+0x93/0x180 ? lock_is_held_type+0xd5/0x130 ? __call_rcu_common.constprop.0+0x3c0/0xfb0 ? lockdep_hardirqs_on+0x78/0x100 ? __call_rcu_common.constprop.0+0x3c0/0xfb0 ? __pfx___call_rcu_common.constprop.0+0x10/0x10 ? kmem_cache_free+0x3a0/0x590 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? __pfx___x64_sys_openat+0x10/0x10 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f436712b68b RSP: 002b:00007ffe9f1a8658 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 00005559b367fd80 RCX: 00007f436712b68b RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00005559b367fde8 RBP: 00007ffe9f1a8680 R08: 1999999999999999 R09: 0000000000000000 R10: 00007f43671a5fe0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffe9f1a86b0 R14: 0000000000000000 R15: 0000000000000000 Reported-by: Shin'ichiro Kawasaki CC: # 6.13+ Tested-by: Shin'ichiro Kawasaki Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Naohiro Aota Signed-off-by: David Sterba --- fs/btrfs/zoned.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 7c502192cd6b..4a3e02b49f29 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -1277,7 +1277,7 @@ struct zone_info { static int btrfs_load_zone_info(struct btrfs_fs_info *fs_info, int zone_idx, struct zone_info *info, unsigned long *active, - struct btrfs_chunk_map *map) + struct btrfs_chunk_map *map, bool new) { struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; struct btrfs_device *device; @@ -1307,6 +1307,8 @@ static int btrfs_load_zone_info(struct btrfs_fs_info *fs_info, int zone_idx, return 0; } + ASSERT(!new || btrfs_dev_is_empty_zone(device, info->physical)); + /* This zone will be used for allocation, so mark this zone non-empty. */ btrfs_dev_clear_zone_empty(device, info->physical); @@ -1319,6 +1321,18 @@ static int btrfs_load_zone_info(struct btrfs_fs_info *fs_info, int zone_idx, * to determine the allocation offset within the zone. */ WARN_ON(!IS_ALIGNED(info->physical, fs_info->zone_size)); + + if (new) { + sector_t capacity; + + capacity = bdev_zone_capacity(device->bdev, info->physical >> SECTOR_SHIFT); + up_read(&dev_replace->rwsem); + info->alloc_offset = 0; + info->capacity = capacity << SECTOR_SHIFT; + + return 0; + } + nofs_flag = memalloc_nofs_save(); ret = btrfs_get_dev_zone(device, info->physical, &zone); memalloc_nofs_restore(nofs_flag); @@ -1588,7 +1602,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new) } for (i = 0; i < map->num_stripes; i++) { - ret = btrfs_load_zone_info(fs_info, i, &zone_info[i], active, map); + ret = btrfs_load_zone_info(fs_info, i, &zone_info[i], active, map, new); if (ret) goto out;