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2024-12-14btrfs: fix mount failure due to remount racesQu Wenruo
[ Upstream commit 951a3f59d268fe1397aaeb9a96fcb1944890c4cb ] [BUG] The following reproducer can cause btrfs mount to fail: dev="/dev/test/scratch1" mnt1="/mnt/test" mnt2="/mnt/scratch" mkfs.btrfs -f $dev mount $dev $mnt1 btrfs subvolume create $mnt1/subvol1 btrfs subvolume create $mnt1/subvol2 umount $mnt1 mount $dev $mnt1 -o subvol=subvol1 while mount -o remount,ro $mnt1; do mount -o remount,rw $mnt1; done & bg=$! while mount $dev $mnt2 -o subvol=subvol2; do umount $mnt2; done kill $bg wait umount -R $mnt1 umount -R $mnt2 The script will fail with the following error: mount: /mnt/scratch: /dev/mapper/test-scratch1 already mounted on /mnt/test. dmesg(1) may have more information after failed mount system call. umount: /mnt/test: target is busy. umount: /mnt/scratch/: not mounted And there is no kernel error message. [CAUSE] During the btrfs mount, to support mounting different subvolumes with different RO/RW flags, we need to detect that and retry if needed: Retry with matching RO flags if the initial mount fail with -EBUSY. The problem is, during that retry we do not hold any super block lock (s_umount), this means there can be a remount process changing the RO flags of the original fs super block. If so, we can have an EBUSY error during retry. And this time we treat any failure as an error, without any retry and cause the above EBUSY mount failure. [FIX] The current retry behavior is racy because we do not have a super block thus no way to hold s_umount to prevent the race with remount. Solve the root problem by allowing fc->sb_flags to mismatch from the sb->s_flags at btrfs_get_tree_super(). Then at the re-entry point btrfs_get_tree_subvol(), manually check the fc->s_flags against sb->s_flags, if it's a RO->RW mismatch, then reconfigure with s_umount lock hold. Reported-by: Enno Gotthold <egotthold@suse.com> Reported-by: Fabian Vogt <fvogt@suse.com> [ Special thanks for the reproducer and early analysis pointing to btrfs. ] Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes") Link: https://bugzilla.suse.com/show_bug.cgi?id=1231836 Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: drop unused parameter data from btrfs_fill_super()David Sterba
[ Upstream commit 01c5db782e3ad1aea1d06a1765c710328c145f10 ] The only caller passes NULL, we can drop the parameter. This is since the new mount option parser done in 3bb17a25bcb09a ("btrfs: add get_tree callback for new mount API"). Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 951a3f59d268 ("btrfs: fix mount failure due to remount races") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: drop unused parameter options from open_ctree()David Sterba
[ Upstream commit 87cbab86366e75dec52f787e0e0b17b2aea769ca ] Since the new mount option parser in commit ad21f15b0f79 ("btrfs: switch to the new mount API") we don't pass the options like that anymore. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 951a3f59d268 ("btrfs: fix mount failure due to remount races") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: do not clear read-only when adding sprout deviceBoris Burkov
[ Upstream commit 70958a949d852cbecc3d46127bf0b24786df0130 ] If you follow the seed/sprout wiki, it suggests the following workflow: btrfstune -S 1 seed_dev mount seed_dev mnt btrfs device add sprout_dev mount -o remount,rw mnt The first mount mounts the FS readonly, which results in not setting BTRFS_FS_OPEN, and setting the readonly bit on the sb. The device add somewhat surprisingly clears the readonly bit on the sb (though the mount is still practically readonly, from the users perspective...). Finally, the remount checks the readonly bit on the sb against the flag and sees no change, so it does not run the code intended to run on ro->rw transitions, leaving BTRFS_FS_OPEN unset. As a result, when the cleaner_kthread runs, it sees no BTRFS_FS_OPEN and does no work. This results in leaking deleted snapshots until we run out of space. I propose fixing it at the first departure from what feels reasonable: when we clear the readonly bit on the sb during device add. A new fstest I have written reproduces the bug and confirms the fix. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: canonicalize the device path before adding itQu Wenruo
[ Upstream commit 7e06de7c83a746e58d4701e013182af133395188 ] [PROBLEM] Currently btrfs accepts any file path for its device, resulting some weird situation: # ./mount_by_fd /dev/test/scratch1 /mnt/btrfs/ The program has the following source code: #include <fcntl.h> #include <stdio.h> #include <sys/mount.h> int main(int argc, char *argv[]) { int fd = open(argv[1], O_RDWR); char path[256]; snprintf(path, sizeof(path), "/proc/self/fd/%d", fd); return mount(path, argv[2], "btrfs", 0, NULL); } Then we can have the following weird device path: BTRFS: device fsid 2378be81-fe12-46d2-a9e8-68cf08dd98d5 devid 1 transid 7 /proc/self/fd/3 (253:2) scanned by mount_by_fd (18440) Normally it's not a big deal, and later udev can trigger a device path rename. But if udev didn't trigger, the device path "/proc/self/fd/3" will show up in mtab. [CAUSE] For filename "/proc/self/fd/3", it means the opened file descriptor 3. In above case, it's exactly the device we want to open, aka points to "/dev/test/scratch1" which is another symlink pointing to "/dev/dm-2". Inside kernel we solve the mount source using LOOKUP_FOLLOW, which follows the symbolic link and grab the proper block device. But inside btrfs we also save the filename into btrfs_device::name, and utilize that member to report our mount source, which leads to the above situation. [FIX] Instead of unconditionally trust the path, check if the original file (not following the symbolic link) is inside "/dev/", if not, then manually lookup the path to its final destination, and use that as our device path. This allows us to still use symbolic links, like "/dev/mapper/test-scratch" from LVM2, which is required for fstests runs with LVM2 setup. And for really weird names, like the above case, we solve it to "/dev/dm-2" instead. Reviewed-by: Filipe Manana <fdmanana@suse.com> Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641 Reported-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: avoid unnecessary device path update for the same deviceQu Wenruo
[ Upstream commit 2e8b6bc0ab41ce41e6dfcc204b6cc01d5abbc952 ] [PROBLEM] It is very common for udev to trigger device scan, and every time a mounted btrfs device got re-scan from different soft links, we will get some of unnecessary device path updates, this is especially common for LVM based storage: # lvs scratch1 test -wi-ao---- 10.00g scratch2 test -wi-a----- 10.00g scratch3 test -wi-a----- 10.00g scratch4 test -wi-a----- 10.00g scratch5 test -wi-a----- 10.00g test test -wi-a----- 10.00g # mkfs.btrfs -f /dev/test/scratch1 # mount /dev/test/scratch1 /mnt/btrfs # dmesg -c [ 205.705234] BTRFS: device fsid 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 devid 1 transid 6 /dev/mapper/test-scratch1 (253:4) scanned by mount (1154) [ 205.710864] BTRFS info (device dm-4): first mount of filesystem 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 [ 205.711923] BTRFS info (device dm-4): using crc32c (crc32c-intel) checksum algorithm [ 205.713856] BTRFS info (device dm-4): using free-space-tree [ 205.722324] BTRFS info (device dm-4): checking UUID tree So far so good, but even if we just touched any soft link of "dm-4", we will get quite some unnecessary device path updates. # touch /dev/mapper/test-scratch1 # dmesg -c [ 469.295796] BTRFS info: devid 1 device path /dev/mapper/test-scratch1 changed to /dev/dm-4 scanned by (udev-worker) (1221) [ 469.300494] BTRFS info: devid 1 device path /dev/dm-4 changed to /dev/mapper/test-scratch1 scanned by (udev-worker) (1221) Such device path rename is unnecessary and can lead to random path change due to the udev race. [CAUSE] Inside device_list_add(), we are using a very primitive way checking if the device has changed, strcmp(). Which can never handle links well, no matter if it's hard or soft links. So every different link of the same device will be treated as a different device, causing the unnecessary device path update. [FIX] Introduce a helper, is_same_device(), and use path_equal() to properly detect the same block device. So that the different soft links won't trigger the rename race. Reviewed-by: Filipe Manana <fdmanana@suse.com> Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641 Reported-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14btrfs: don't take dev_replace rwsem on task already holding itJohannes Thumshirn
[ Upstream commit 8cca35cb29f81eba3e96ec44dad8696c8a2f9138 ] Running fstests btrfs/011 with MKFS_OPTIONS="-O rst" to force the usage of the RAID stripe-tree, we get the following splat from lockdep: BTRFS info (device sdd): dev_replace from /dev/sdd (devid 1) to /dev/sdb started ============================================ WARNING: possible recursive locking detected 6.11.0-rc3-btrfs-for-next #599 Not tainted -------------------------------------------- btrfs/2326 is trying to acquire lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 but task is already holding lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&fs_info->dev_replace.rwsem); lock(&fs_info->dev_replace.rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by btrfs/2326: #0: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 stack backtrace: CPU: 1 UID: 0 PID: 2326 Comm: btrfs Not tainted 6.11.0-rc3-btrfs-for-next #599 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x5b/0x80 __lock_acquire+0x2798/0x69d0 ? __pfx___lock_acquire+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x19d/0x4a0 ? btrfs_map_block+0x39f/0x2250 ? __pfx_lock_acquire+0x10/0x10 ? find_held_lock+0x2d/0x110 ? lock_is_held_type+0x8f/0x100 down_read+0x8e/0x440 ? btrfs_map_block+0x39f/0x2250 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x39f/0x2250 ? btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? btrfs_bio_counter_inc_blocked+0xd9/0x2e0 ? __kasan_slab_alloc+0x6e/0x70 ? __pfx_btrfs_map_block+0x10/0x10 ? __pfx_btrfs_bio_counter_inc_blocked+0x10/0x10 ? kmem_cache_alloc_noprof+0x1f2/0x300 ? mempool_alloc_noprof+0xed/0x2b0 btrfs_submit_chunk+0x28d/0x17e0 ? __pfx_btrfs_submit_chunk+0x10/0x10 ? bvec_alloc+0xd7/0x1b0 ? bio_add_folio+0x171/0x270 ? __pfx_bio_add_folio+0x10/0x10 ? __kasan_check_read+0x20/0x20 btrfs_submit_bio+0x37/0x80 read_extent_buffer_pages+0x3df/0x6c0 btrfs_read_extent_buffer+0x13e/0x5f0 read_tree_block+0x81/0xe0 read_block_for_search+0x4bd/0x7a0 ? __pfx_read_block_for_search+0x10/0x10 btrfs_search_slot+0x78d/0x2720 ? __pfx_btrfs_search_slot+0x10/0x10 ? lock_is_held_type+0x8f/0x100 ? kasan_save_track+0x14/0x30 ? __kasan_slab_alloc+0x6e/0x70 ? kmem_cache_alloc_noprof+0x1f2/0x300 btrfs_get_raid_extent_offset+0x181/0x820 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_btrfs_get_raid_extent_offset+0x10/0x10 ? down_read+0x194/0x440 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x5b5/0x2250 ? __pfx_btrfs_map_block+0x10/0x10 scrub_submit_initial_read+0x8fe/0x11b0 ? __pfx_scrub_submit_initial_read+0x10/0x10 submit_initial_group_read+0x161/0x3a0 ? lock_release+0x20e/0x710 ? __pfx_submit_initial_group_read+0x10/0x10 ? __pfx_lock_release+0x10/0x10 scrub_simple_mirror.isra.0+0x3eb/0x580 scrub_stripe+0xe4d/0x1440 ? lock_release+0x20e/0x710 ? __pfx_scrub_stripe+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 scrub_chunk+0x257/0x4a0 scrub_enumerate_chunks+0x64c/0xf70 ? __mutex_unlock_slowpath+0x147/0x5f0 ? __pfx_scrub_enumerate_chunks+0x10/0x10 ? bit_wait_timeout+0xb0/0x170 ? __up_read+0x189/0x700 ? scrub_workers_get+0x231/0x300 ? up_write+0x490/0x4f0 btrfs_scrub_dev+0x52e/0xcd0 ? create_pending_snapshots+0x230/0x250 ? __pfx_btrfs_scrub_dev+0x10/0x10 btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? lock_acquire+0x19d/0x4a0 ? __pfx_btrfs_dev_replace_by_ioctl+0x10/0x10 ? lock_release+0x20e/0x710 ? btrfs_ioctl+0xa09/0x74f0 ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_lock+0x11e/0x240 ? __pfx_do_raw_spin_lock+0x10/0x10 btrfs_ioctl+0xa14/0x74f0 ? lock_acquire+0x19d/0x4a0 ? find_held_lock+0x2d/0x110 ? __pfx_btrfs_ioctl+0x10/0x10 ? lock_release+0x20e/0x710 ? do_sigaction+0x3f0/0x860 ? __pfx_do_vfs_ioctl+0x10/0x10 ? do_raw_spin_lock+0x11e/0x240 ? lockdep_hardirqs_on_prepare+0x270/0x3e0 ? _raw_spin_unlock_irq+0x28/0x50 ? do_sigaction+0x3f0/0x860 ? __pfx_do_sigaction+0x10/0x10 ? __x64_sys_rt_sigaction+0x18e/0x1e0 ? __pfx___x64_sys_rt_sigaction+0x10/0x10 ? __x64_sys_close+0x7c/0xd0 __x64_sys_ioctl+0x137/0x190 do_syscall_64+0x71/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0bd1114f9b Code: Unable to access opcode bytes at 0x7f0bd1114f71. RSP: 002b:00007ffc8a8c3130 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0bd1114f9b RDX: 00007ffc8a8c35e0 RSI: 00000000ca289435 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc8a8c6c85 R13: 00000000398e72a0 R14: 0000000000004361 R15: 0000000000000004 </TASK> This happens because on RAID stripe-tree filesystems we recurse back into btrfs_map_block() on scrub to perform the logical to device physical mapping. But as the device replace task is already holding the dev_replace::rwsem we deadlock. So don't take the dev_replace::rwsem in case our task is the task performing the device replace. Suggested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: ref-verify: fix use-after-free after invalid ref actionFilipe Manana
[ Upstream commit 7c4e39f9d2af4abaf82ca0e315d1fd340456620f ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: add a sanity check for btrfs root in btrfs_search_slot()Lizhi Xu
[ Upstream commit 3ed51857a50f530ac7a1482e069dfbd1298558d4 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: don't loop for nowait writes when checking for cross referencesFilipe Manana
[ Upstream commit ed67f2a913a4f0fc505db29805c41dd07d3cb356 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: fix use-after-free in btrfs_encoded_read_endio()Johannes Thumshirn
[ Upstream commit 05b36b04d74a517d6675bf2f90829ff1ac7e28dc ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()Mark Harmstone
[ Upstream commit 68d3b27e05c7ca5545e88465f5e2be6eda0e11df ] 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> Stable-dep-of: 05b36b04d74a ("btrfs: fix use-after-free in btrfs_encoded_read_endio()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: change btrfs_encoded_read() so that reading of extent is done by callerMark Harmstone
[ Upstream commit 26efd44796c6dd7a64f039a0dda6d558eac97a3e ] 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> Stable-dep-of: 05b36b04d74a ("btrfs: fix use-after-free in btrfs_encoded_read_endio()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09btrfs: drop unused parameter file_offset from ↵David Sterba
btrfs_encoded_read_regular_fill_pages() [ Upstream commit 590168edbe6317ca9f4066215fb099f43ffe745c ] The file_offset parameter used to be passed to encoded read struct but was removed in commit b665affe93d8 ("btrfs: remove unused members from struct btrfs_encoded_read_private"). Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 05b36b04d74a ("btrfs: fix use-after-free in btrfs_encoded_read_endio()") Signed-off-by: Sasha Levin <sashal@kernel.org>
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>
2024-11-08Merge tag 'for-6.12-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more one-liners that fix some user visible problems: - use correct range when clearing qgroup reservations after COW - properly reset freed delayed ref list head - fix ro/rw subvolume mounts to be backward compatible with old and new mount API" * tag 'for-6.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix the length of reserved qgroup to free btrfs: reinitialize delayed ref list after deleting it from the list btrfs: fix per-subvolume RO/RW flags with new mount API
2024-11-07btrfs: fix the length of reserved qgroup to freeHaisu Wang
The dealloc flag may be cleared and the extent won't reach the disk in cow_file_range when errors path. The reserved qgroup space is freed in commit 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range"). However, the length of untouched region to free needs to be adjusted with the correct remaining region size. Fixes: 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range") CC: stable@vger.kernel.org # 6.11+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Haisu Wang <haisuwang@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07btrfs: reinitialize delayed ref list after deleting it from the listFilipe Manana
At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead. Fixes: 1d57ee941692 ("btrfs: improve delayed refs iterations") 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>
2024-11-07btrfs: fix per-subvolume RO/RW flags with new mount APIQu Wenruo
[BUG] With util-linux 2.40.2, the 'mount' utility is already utilizing the new mount API. e.g: # strace mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test/ ... fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 But this leads to a new problem, that per-subvolume RO/RW mount no longer works, if the initial mount is RO: # mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test # mount -o rw,subvol=subv2 /dev/test/scratch1 /mnt/scratch # mount | grep mnt /dev/mapper/test-scratch1 on /mnt/test type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=256,subvol=/subv1) /dev/mapper/test-scratch1 on /mnt/scratch type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=257,subvol=/subv2) # touch /mnt/scratch/foobar touch: cannot touch '/mnt/scratch/foobar': Read-only file system This is a common use cases on distros. [CAUSE] We have a workaround for remount to handle the RO->RW change, but if the mount is using the new mount API, we do not do that, and rely on the mount tool NOT to set the ro flag. But that's not how the mount tool is doing for the new API: fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 <<<< Setting RO flag for super block fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 This means we will set the super block RO at the first mount. Later RW mount will not try to reconfigure the fs to RW because the mount tool is already using the new API. This totally breaks the per-subvolume RO/RW mount behavior. [FIX] Do not skip the reconfiguration even if using the new API. The old comments are just expecting any mount tool to properly skip the RO flag set even if we specify "ro", which is not the reality. Update the comments regarding the backward compatibility on the kernel level so it works with old and new mount utilities. CC: stable@vger.kernel.org # 6.8+ Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes") Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-01Merge tag 'for-6.12-rc5-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more stability fixes. There's one patch adding export of MIPS cmpxchg helper, used in the error propagation fix. - fix error propagation from split bios to the original btrfs bio - fix merging of adjacent extents (normal operation, defragmentation) - fix potential use after free after freeing btrfs device structures" * tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix defrag not merging contiguous extents due to merged extent maps btrfs: fix extent map merging not happening for adjacent extents btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids() btrfs: fix error propagation of split bios MIPS: export __cmpxchg_small()
2024-10-31btrfs: fix defrag not merging contiguous extents due to merged extent mapsFilipe Manana
When running defrag (manual defrag) against a file that has extents that are contiguous and we already have the respective extent maps loaded and merged, we end up not defragging the range covered by those contiguous extents. This happens when we have an extent map that was the result of merging multiple extent maps for contiguous extents and the length of the merged extent map is greater than or equals to the defrag threshold length. The script below reproduces this scenario: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create a 256K file with 4 extents of 64K each. xfs_io -f -c "falloc 0 64K" \ -c "pwrite 0 64K" \ -c "falloc 64K 64K" \ -c "pwrite 64K 64K" \ -c "falloc 128K 64K" \ -c "pwrite 128K 64K" \ -c "falloc 192K 64K" \ -c "pwrite 192K 64K" \ $MNT/foo umount $MNT echo -n "Initial number of file extent items: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 128K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 128K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 256K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 256K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l Running it: $ ./test.sh Initial number of file extent items: 4 Number of file extent items after defrag with 128K threshold: 4 Number of file extent items after defrag with 256K threshold: 4 The 4 extents don't get merged because we have an extent map with a size of 256K that is the result of merging the individual extent maps for each of the four 64K extents and at defrag_lookup_extent() we have a value of zero for the generation threshold ('newer_than' argument) since this is a manual defrag. As a consequence we don't call defrag_get_extent() to get an extent map representing a single file extent item in the inode's subvolume tree, so we end up using the merged extent map at defrag_collect_targets() and decide not to defrag. Fix this by updating defrag_lookup_extent() to always discard extent maps that were merged and call defrag_get_extent() regardless of the minimum generation threshold ('newer_than' argument). A test case for fstests will be sent along soon. CC: stable@vger.kernel.org # 6.1+ Fixes: 199257a78bb0 ("btrfs: defrag: don't use merged extent map for their generation check") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-31btrfs: fix extent map merging not happening for adjacent extentsFilipe Manana
If we have 3 or more adjacent extents in a file, that is, consecutive file extent items pointing to adjacent extents, within a contiguous file range and compatible flags, we end up not merging all the extents into a single extent map. For example: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt/sdc $ xfs_io -f -d -c "pwrite -b 64K 0 64K" \ -c "pwrite -b 64K 64K 64K" \ -c "pwrite -b 64K 128K 64K" \ -c "pwrite -b 64K 192K 64K" \ /mnt/sdc/foo After all the ordered extents complete we unpin the extent maps and try to merge them, but instead of getting a single extent map we get two because: 1) When the first ordered extent completes (file range [0, 64K)) we unpin its extent map and attempt to merge it with the extent map for the range [64K, 128K), but we can't because that extent map is still pinned; 2) When the second ordered extent completes (file range [64K, 128K)), we unpin its extent map and merge it with the previous extent map, for file range [0, 64K), but we can't merge with the next extent map, for the file range [128K, 192K), because this one is still pinned. The merged extent map for the file range [0, 128K) gets the flag EXTENT_MAP_MERGED set; 3) When the third ordered extent completes (file range [128K, 192K)), we unpin its extent map and attempt to merge it with the previous extent map, for file range [0, 128K), but we can't because that extent map has the flag EXTENT_MAP_MERGED set (mergeable_maps() returns false due to different flags) while the extent map for the range [128K, 192K) doesn't have that flag set. We also can't merge it with the next extent map, for file range [192K, 256K), because that one is still pinned. At this moment we have 3 extent maps: One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set. One for file range [128K, 192K). One for file range [192K, 256K) which is still pinned; 4) When the fourth and final extent completes (file range [192K, 256K)), we unpin its extent map and attempt to merge it with the previous extent map, for file range [128K, 192K), which succeeds since none of these extent maps have the EXTENT_MAP_MERGED flag set. So we end up with 2 extent maps: One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set. One for file range [128K, 256K), with the flag EXTENT_MAP_MERGED set. Since after merging extent maps we don't attempt to merge again, that is, merge the resulting extent map with the one that is now preceding it (and the one following it), we end up with those two extent maps, when we could have had a single extent map to represent the whole file. Fix this by making mergeable_maps() ignore the EXTENT_MAP_MERGED flag. While this doesn't present any functional issue, it prevents the merging of extent maps which allows to save memory, and can make defrag not merging extents too (that will be addressed in the next patch). Fixes: 199257a78bb0 ("btrfs: defrag: don't use merged extent map for their generation check") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-29btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()Zhihao Cheng
Mounting btrfs from two images (which have the same one fsid and two different dev_uuids) in certain executing order may trigger an UAF for variable 'device->bdev_file' in __btrfs_free_extra_devids(). And following are the details: 1. Attach image_1 to loop0, attach image_2 to loop1, and scan btrfs devices by ioctl(BTRFS_IOC_SCAN_DEV): / btrfs_device_1 → loop0 fs_device \ btrfs_device_2 → loop1 2. mount /dev/loop0 /mnt btrfs_open_devices btrfs_device_1->bdev_file = btrfs_get_bdev_and_sb(loop0) btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree fail: btrfs_close_devices // -ENOMEM btrfs_close_bdev(btrfs_device_1) fput(btrfs_device_1->bdev_file) // btrfs_device_1->bdev_file is freed btrfs_close_bdev(btrfs_device_2) fput(btrfs_device_2->bdev_file) 3. mount /dev/loop1 /mnt btrfs_open_devices btrfs_get_bdev_and_sb(&bdev_file) // EIO, btrfs_device_1->bdev_file is not assigned, // which points to a freed memory area btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree btrfs_free_extra_devids if (btrfs_device_1->bdev_file) fput(btrfs_device_1->bdev_file) // UAF ! Fix it by setting 'device->bdev_file' as 'NULL' after closing the btrfs_device in btrfs_close_one_device(). Fixes: 142388194191 ("btrfs: do not background blkdev_put()") CC: stable@vger.kernel.org # 4.19+ Link: https://bugzilla.kernel.org/show_bug.cgi?id=219408 Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-24Merge tag 'for-6.12-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - mount option fixes: - fix handling of compression mount options on remount - reject rw remount in case there are options that don't work in read-write mode (like rescue options) - fix zone accounting of unusable space - fix in-memory corruption when merging extent maps - fix delalloc range locking for sector < page - use more convenient default value of drop subtree threshold, clean more subvolumes without the fallback to marking quotas inconsistent - fix smatch warning about incorrect value passed to ERR_PTR * tag 'for-6.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix passing 0 to ERR_PTR in btrfs_search_dir_index_item() btrfs: reject ro->rw reconfiguration if there are hard ro requirements btrfs: fix read corruption due to race with extent map merging btrfs: fix the delalloc range locking if sector size < page size btrfs: qgroup: set a more sane default value for subtree drop threshold btrfs: clear force-compress on remount when compress mount option is given btrfs: zoned: fix zone unusable accounting for freed reserved extent
2024-10-23btrfs: fix error propagation of split biosNaohiro Aota
The purpose of btrfs_bbio_propagate_error() shall be propagating an error of split bio to its original btrfs_bio, and tell the error to the upper layer. However, it's not working well on some cases. * Case 1. Immediate (or quick) end_bio with an error When btrfs sends btrfs_bio to mirrored devices, btrfs calls btrfs_bio_end_io() when all the mirroring bios are completed. If that btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error() accesses the orig_bbio's bio context to increase the error count. That works well in most cases. However, if the end_io is called enough fast, orig_bbio's (remaining part after split) bio context may not be properly set at that time. Since the bio context is set when the orig_bbio (the last btrfs_bio) is sent to devices, that might be too late for earlier split btrfs_bio's completion. That will result in NULL pointer dereference. That bug is easily reproducible by running btrfs/146 on zoned devices [1] and it shows the following trace. [1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ #474 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: writeback wb_workfn (flush-btrfs-5) RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs] BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0 RSP: 0018:ffffc9000006f248 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080 RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58 R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158 FS: 0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body.cold+0x19/0x26 ? page_fault_oops+0x13e/0x2b0 ? _printk+0x58/0x73 ? do_user_addr_fault+0x5f/0x750 ? exc_page_fault+0x76/0x240 ? asm_exc_page_fault+0x22/0x30 ? btrfs_bio_end_io+0xae/0xc0 [btrfs] ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs] btrfs_orig_write_end_io+0x51/0x90 [btrfs] dm_submit_bio+0x5c2/0xa50 [dm_mod] ? find_held_lock+0x2b/0x80 ? blk_try_enter_queue+0x90/0x1e0 __submit_bio+0xe0/0x130 ? ktime_get+0x10a/0x160 ? lockdep_hardirqs_on+0x74/0x100 submit_bio_noacct_nocheck+0x199/0x410 btrfs_submit_bio+0x7d/0x150 [btrfs] btrfs_submit_chunk+0x1a1/0x6d0 [btrfs] ? lockdep_hardirqs_on+0x74/0x100 ? __folio_start_writeback+0x10/0x2c0 btrfs_submit_bbio+0x1c/0x40 [btrfs] submit_one_bio+0x44/0x60 [btrfs] submit_extent_folio+0x13f/0x330 [btrfs] ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs] extent_writepage_io+0x18b/0x360 [btrfs] extent_write_locked_range+0x17c/0x340 [btrfs] ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs] run_delalloc_cow+0x71/0xd0 [btrfs] btrfs_run_delalloc_range+0x176/0x500 [btrfs] ? find_lock_delalloc_range+0x119/0x260 [btrfs] writepage_delalloc+0x2ab/0x480 [btrfs] extent_write_cache_pages+0x236/0x7d0 [btrfs] btrfs_writepages+0x72/0x130 [btrfs] do_writepages+0xd4/0x240 ? find_held_lock+0x2b/0x80 ? wbc_attach_and_unlock_inode+0x12c/0x290 ? wbc_attach_and_unlock_inode+0x12c/0x290 __writeback_single_inode+0x5c/0x4c0 ? do_raw_spin_unlock+0x49/0xb0 writeback_sb_inodes+0x22c/0x560 __writeback_inodes_wb+0x4c/0xe0 wb_writeback+0x1d6/0x3f0 wb_workfn+0x334/0x520 process_one_work+0x1ee/0x570 ? lock_is_held_type+0xc6/0x130 worker_thread+0x1d1/0x3b0 ? __pfx_worker_thread+0x10/0x10 kthread+0xee/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: dm_mod btrfs blake2b_generic xor raid6_pq rapl CR2: 0000000000000020 * Case 2. Earlier completion of orig_bbio for mirrored btrfs_bios btrfs_bbio_propagate_error() assumes the end_io function for orig_bbio is called last among split bios. In that case, btrfs_orig_write_end_io() sets the bio->bi_status to BLK_STS_IOERR by seeing the bioc->error [2]. Otherwise, the increased orig_bio's bioc->error is not checked by anyone and return BLK_STS_OK to the upper layer. [2] Actually, this is not true. Because we only increases orig_bioc->errors by max_errors, the condition "atomic_read(&bioc->error) > bioc->max_errors" is still not met if only one split btrfs_bio fails. * Case 3. Later completion of orig_bbio for un-mirrored btrfs_bios In contrast to the above case, btrfs_bbio_propagate_error() is not working well if un-mirrored orig_bbio is completed last. It sets orig_bbio->bio.bi_status to the btrfs_bio's error. But, that is easily over-written by orig_bbio's completion status. If the status is BLK_STS_OK, the upper layer would not know the failure. * Solution Considering the above cases, we can only save the error status in the orig_bbio (remaining part after split) itself as it is always available. Also, the saved error status should be propagated when all the split btrfs_bios are finished (i.e, bbio->pending_ios == 0). This commit introduces "status" to btrfs_bbio and saves the first error of split bios to original btrfs_bio's "status" variable. When all the split bios are finished, the saved status is loaded into original btrfs_bio's status. With this commit, btrfs/146 on zoned devices does not hit the NULL pointer dereference anymore. Fixes: 852eee62d31a ("btrfs: allow btrfs_submit_bio to split bios") CC: stable@vger.kernel.org # 6.6+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: fix passing 0 to ERR_PTR in btrfs_search_dir_index_item()Yue Haibing
The ret may be zero in btrfs_search_dir_index_item() and should not passed to ERR_PTR(). Now btrfs_unlink_subvol() is the only caller to this, reconstructed it to check ERR_PTR(-ENOENT) while ret >= 0. This fixes smatch warnings: fs/btrfs/dir-item.c:353 btrfs_search_dir_index_item() warn: passing zero to 'ERR_PTR' Fixes: 9dcbe16fccbb ("btrfs: use btrfs_for_each_slot in btrfs_search_dir_index_item") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: reject ro->rw reconfiguration if there are hard ro requirementsQu Wenruo
[BUG] Syzbot reports the following crash: BTRFS info (device loop0 state MCS): disabling free space tree BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline] RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041 Call Trace: <TASK> btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530 btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312 btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012 btrfs_remount_rw fs/btrfs/super.c:1309 [inline] btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534 btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline] btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3472 do_mount fs/namespace.c:3812 [inline] __do_sys_mount fs/namespace.c:4020 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997 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 [CAUSE] To support mounting different subvolume with different RO/RW flags for the new mount APIs, btrfs introduced two workaround to support this feature: - Skip mount option/feature checks if we are mounting a different subvolume - Reconfigure the fs to RW if the initial mount is RO Combining these two, we can have the following sequence: - Mount the fs ro,rescue=all,clear_cache,space_cache=v1 rescue=all will mark the fs as hard read-only, so no v2 cache clearing will happen. - Mount a subvolume rw of the same fs. We go into btrfs_get_tree_subvol(), but fc_mount() returns EBUSY because our new fc is RW, different from the original fs. Now we enter btrfs_reconfigure_for_mount(), which switches the RO flag first so that we can grab the existing fs_info. Then we reconfigure the fs to RW. - During reconfiguration, option/features check is skipped This means we will restart the v2 cache clearing, and convert back to v1 cache. This will trigger fs writes, and since the original fs has "rescue=all" option, it skips the csum tree read. And eventually causing NULL pointer dereference in super block writeback. [FIX] For reconfiguration caused by different subvolume RO/RW flags, ensure we always run btrfs_check_options() to ensure we have proper hard RO requirements met. In fact the function btrfs_check_options() doesn't really do many complex checks, but hard RO requirement and some feature dependency checks, thus there is no special reason not to do the check for mount reconfiguration. Reported-by: syzbot+56360f93efa90ff15870@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/0000000000008c5d090621cb2770@google.com/ Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes") CC: stable@vger.kernel.org # 6.8+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: fix read corruption due to race with extent map mergingBoris Burkov
In debugging some corrupt squashfs files, we observed symptoms of corrupt page cache pages but correct on-disk contents. Further investigation revealed that the exact symptom was a correct page followed by an incorrect, duplicate, page. This got us thinking about extent maps. commit ac05ca913e9f ("Btrfs: fix race between using extent maps and merging them") enforces a reference count on the primary `em` extent_map being merged, as that one gets modified. However, since, commit 3d2ac9922465 ("btrfs: introduce new members for extent_map") both 'em' and 'merge' get modified, which started modifying 'merge' and thus introduced the same race. We were able to reproduce this by looping the affected squashfs workload in parallel on a bunch of separate btrfs-es while also dropping caches. We are still working on a simple enough reproducer to make into an fstest. The simplest fix is to stop modifying 'merge', which is not essential, as it is dropped immediately after the merge. This behavior is simply a consequence of the order of the two extent maps being important in computing the new values. Modify merge_ondisk_extents to take prev and next by const* and also take a third merged parameter that it puts the results in. Note that this introduces the rather odd behavior of passing 'em' to merge_ondisk_extents as a const * and as a regular ptr. Fixes: 3d2ac9922465 ("btrfs: introduce new members for extent_map") CC: stable@vger.kernel.org # 6.11+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: fix the delalloc range locking if sector size < page sizeQu Wenruo
Inside lock_delalloc_folios(), there are several problems related to sector size < page size handling: - Set the writer locks without checking if the folio is still valid We call btrfs_folio_start_writer_lock() just like it's folio_lock(). But since the folio may not even be the folio of the current mapping, we can easily screw up the folio->private. - The range is not clamped inside the page This means we can over write other bitmaps if the start/len is not properly handled, and trigger the btrfs_subpage_assert(). - @processed_end is always rounded up to page end If the delalloc range is not page aligned, and we need to retry (returning -EAGAIN), then we will unlock to the page end. Thankfully this is not a huge problem, as now btrfs_folio_end_writer_lock() can handle range larger than the locked range, and only unlock what is already locked. Fix all these problems by: - Lock and check the folio first, then call btrfs_folio_set_writer_lock() So that if we got a folio not belonging to the inode, we won't touch folio->private. - Properly truncate the range inside the page - Update @processed_end to the locked range end Fixes: 1e1de38792e0 ("btrfs: make process_one_page() to handle subpage locking") CC: stable@vger.kernel.org # 6.1+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: qgroup: set a more sane default value for subtree drop thresholdQu Wenruo
Since commit 011b46c30476 ("btrfs: skip subtree scan if it's too high to avoid low stall in btrfs_commit_transaction()"), btrfs qgroup can automatically skip large subtree scan at the cost of marking qgroup inconsistent. It's designed to address the final performance problem of snapshot drop with qgroup enabled, but to be safe the default value is BTRFS_MAX_LEVEL, requiring a user space daemon to set a different value to make it work. I'd say it's not a good idea to rely on user space tool to set this default value, especially when some operations (snapshot dropping) can be triggered immediately after mount, leaving a very small window to that that sysfs interface. So instead of disabling this new feature by default, enable it with a low threshold (3), so that large subvolume tree drop at mount time won't cause huge qgroup workload. CC: stable@vger.kernel.org # 6.1 Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22btrfs: clear force-compress on remount when compress mount option is givenFilipe Manana
After the migration to use fs context for processing mount options we had a slight change in the semantics for remounting a filesystem that was mounted with compress-force. Before we could clear compress-force by passing only "-o compress[=algo]" during a remount, but after that change that does not work anymore, force-compress is still present and one needs to pass "-o compress-force=no,compress[=algo]" to the mount command. Example, when running on a kernel 6.8+: $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/) $ mount -o remount,compress=zlib:5 /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/) On a 6.7 kernel (or older): $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/) $ mount -o remount,compress=zlib:5 /mnt/sdi $ mount | grep sdi /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/) So update btrfs_parse_param() to clear "compress-force" when "compress" is given, providing the same semantics as kernel 6.7 and older. Reported-by: Roman Mamedov <rm@romanrm.net> Link: https://lore.kernel.org/linux-btrfs/20241014182416.13d0f8b0@nvm/ CC: stable@vger.kernel.org # 6.8+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-17btrfs: zoned: fix zone unusable accounting for freed reserved extentNaohiro Aota
When btrfs reserves an extent and does not use it (e.g, by an error), it calls btrfs_free_reserved_extent() to free the reserved extent. In the process, it calls btrfs_add_free_space() and then it accounts the region bytes as block_group->zone_unusable. However, it leaves the space_info->bytes_zone_unusable side not updated. As a result, ENOSPC can happen while a space_info reservation succeeded. The reservation is fine because the freed region is not added in space_info->bytes_zone_unusable, leaving that space as "free". OTOH, corresponding block group counts it as zone_unusable and its allocation pointer is not rewound, we cannot allocate an extent from that block group. That will also negate space_info's async/sync reclaim process, and cause an ENOSPC error from the extent allocation process. Fix that by returning the space to space_info->bytes_zone_unusable. Ideally, since a bio is not submitted for this reserved region, we should return the space to free space and rewind the allocation pointer. But, it needs rework on extent allocation handling, so let it work in this way for now. Fixes: 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-16Merge tag 'for-6.12-rc3-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - regression fix: dirty extents tracked in xarray for qgroups must be adjusted for 32bit platforms - fix potentially freeing uninitialized name in fscrypt structure - fix warning about unneeded variable in a send callback * tag 'for-6.12-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix uninitialized pointer free on read_alloc_one_name() error btrfs: send: cleanup unneeded return variable in changed_verity() btrfs: fix uninitialized pointer free in add_inode_ref() btrfs: use sector numbers as keys for the dirty extents xarray
2024-10-11btrfs: fix uninitialized pointer free on read_alloc_one_name() errorRoi Martin
The function read_alloc_one_name() does not initialize the name field of the passed fscrypt_str struct if kmalloc fails to allocate the corresponding buffer. Thus, it is not guaranteed that fscrypt_str.name is initialized when freeing it. This is a follow-up to the linked patch that fixes the remaining instances of the bug introduced by commit e43eec81c516 ("btrfs: use struct qstr instead of name and namelen pairs"). Link: https://lore.kernel.org/linux-btrfs/20241009080833.1355894-1-jroi.martin@gmail.com/ Fixes: e43eec81c516 ("btrfs: use struct qstr instead of name and namelen pairs") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Roi Martin <jroi.martin@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11btrfs: send: cleanup unneeded return variable in changed_verity()Christian Heusel
As all changed_* functions need to return something, just return 0 directly here, as the verity status is passed via the context. Reported by LKP: fs/btrfs/send.c:6877:5-8: Unneeded variable: "ret". Return "0" on line 6883 Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202410092305.WbyqspH8-lkp@intel.com/ Signed-off-by: Christian Heusel <christian@heusel.eu> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11btrfs: fix uninitialized pointer free in add_inode_ref()Roi Martin
The add_inode_ref() function does not initialize the "name" struct when it is declared. If any of the following calls to "read_one_inode() returns NULL, dir = read_one_inode(root, parent_objectid); if (!dir) { ret = -ENOENT; goto out; } inode = read_one_inode(root, inode_objectid); if (!inode) { ret = -EIO; goto out; } then "name.name" would be freed on "out" before being initialized. out: ... kfree(name.name); This issue was reported by Coverity with CID 1526744. Fixes: e43eec81c516 ("btrfs: use struct qstr instead of name and namelen pairs") CC: stable@vger.kernel.org # 6.6+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Roi Martin <jroi.martin@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11btrfs: use sector numbers as keys for the dirty extents xarrayFilipe Manana
We are using the logical address ("bytenr") of an extent as the key for qgroup records in the dirty extents xarray. This is a problem because the xarrays use "unsigned long" for keys/indices, meaning that on a 32 bits platform any extent starting at or beyond 4G is truncated, which is a too low limitation as virtually everyone is using storage with more than 4G of space. This means a "bytenr" of 4G gets truncated to 0, and so does 8G and 16G for example, resulting in incorrect qgroup accounting. Fix this by using sector numbers as keys instead, that is, using keys that match the logical address right shifted by fs_info->sectorsize_bits, which is what we do for the fs_info->buffer_radix that tracks extent buffers (radix trees also use an "unsigned long" type for keys). This also makes the index space more dense which helps optimize the xarray (as mentioned at Documentation/core-api/xarray.rst). Fixes: 3cce39a8ca4e ("btrfs: qgroup: use xarray to track dirty extents in transaction") 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>
2024-10-10Merge tag 'for-6.12-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - update fstrim loop and add more cancellation points, fix reported delayed or blocked suspend if there's a huge chunk queued - fix error handling in recent qgroup xarray conversion - in zoned mode, fix warning printing device path without RCU protection - again fix invalid extent xarray state (6252690f7e1b), lost due to refactoring * tag 'for-6.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix clear_dirty and writeback ordering in submit_one_sector() btrfs: zoned: fix missing RCU locking in error message when loading zone info btrfs: fix missing error handling when adding delayed ref with qgroups enabled btrfs: add cancellation points to trim loops btrfs: split remaining space to discard in chunks
2024-10-09btrfs: fix clear_dirty and writeback ordering in submit_one_sector()Naohiro Aota
This commit is a replay of commit 6252690f7e1b ("btrfs: fix invalid mapping of extent xarray state"). We need to call btrfs_folio_clear_dirty() before btrfs_set_range_writeback(), so that xarray DIRTY tag is cleared. With a refactoring commit 8189197425e7 ("btrfs: refactor __extent_writepage_io() to do sector-by-sector submission"), it screwed up and the order is reversed and causing the same hang. Fix the ordering now in submit_one_sector(). Fixes: 8189197425e7 ("btrfs: refactor __extent_writepage_io() to do sector-by-sector submission") Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-09btrfs: zoned: fix missing RCU locking in error message when loading zone infoFilipe Manana
At btrfs_load_zone_info() we have an error path that is dereferencing the name of a device which is a RCU string but we are not holding a RCU read lock, which is incorrect. Fix this by using btrfs_err_in_rcu() instead of btrfs_err(). The problem is there since commit 08e11a3db098 ("btrfs: zoned: load zone's allocation offset"), back then at btrfs_load_block_group_zone_info() but then later on that code was factored out into the helper btrfs_load_zone_info() by commit 09a46725cc84 ("btrfs: zoned: factor out per-zone logic from btrfs_load_block_group_zone_info"). Fixes: 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Naohiro Aota <naohiro.aota@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>
2024-10-07btrfs: fix missing error handling when adding delayed ref with qgroups enabledFilipe Manana
When adding a delayed ref head, at delayed-ref.c:add_delayed_ref_head(), if we fail to insert the qgroup record we don't error out, we ignore it. In fact we treat it as if there was no error and there was already an existing record - we don't distinguish between the cases where btrfs_qgroup_trace_extent_nolock() returns 1, meaning a record already existed and we can free the given record, and the case where it returns a negative error value, meaning the insertion into the xarray that is used to track records failed. Effectively we end up ignoring that we are lacking qgroup record in the dirty extents xarray, resulting in incorrect qgroup accounting. Fix this by checking for errors and return them to the callers. Fixes: 3cce39a8ca4e ("btrfs: qgroup: use xarray to track dirty extents in transaction") 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>
2024-10-07btrfs: add cancellation points to trim loopsLuca Stefani
There are reports that system cannot suspend due to running trim because the task responsible for trimming the device isn't able to finish in time, especially since we have a free extent discarding phase, which can trim a lot of unallocated space. There are no limits on the trim size (unlike the block group part). Since trime isn't a critical call it can be interrupted at any time, in such cases we stop the trim, report the amount of discarded bytes and return an error. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219180 Link: https://bugzilla.suse.com/show_bug.cgi?id=1229737 CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-07btrfs: split remaining space to discard in chunksLuca Stefani
Per Qu Wenruo in case we have a very large disk, e.g. 8TiB device, mostly empty although we will do the split according to our super block locations, the last super block ends at 256G, we can submit a huge discard for the range [256G, 8T), causing a large delay. Split the space left to discard based on BTRFS_MAX_DISCARD_CHUNK_SIZE in preparation of introduction of cancellation points to trim. The value of the chunk size is arbitrary, it can be higher or derived from actual device capabilities but we can't easily read that using bio_discard_limit(). Link: https://bugzilla.kernel.org/show_bug.cgi?id=219180 Link: https://bugzilla.suse.com/show_bug.cgi?id=1229737 CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-04Merge tag 'for-6.12-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - in incremental send, fix invalid clone operation for file that got its size decreased - fix __counted_by() annotation of send path cache entries, we do not store the terminating NUL - fix a longstanding bug in relocation (and quite hard to hit by chance), drop back reference cache that can get out of sync after transaction commit - wait for fixup worker kthread before finishing umount - add missing raid-stripe-tree extent for NOCOW files, zoned mode cannot have NOCOW files but RST is meant to be a standalone feature - handle transaction start error during relocation, avoid potential NULL pointer dereference of relocation control structure (reported by syzbot) - disable module-wide rate limiting of debug level messages - minor fix to tracepoint definition (reported by checkpatch.pl) * tag 'for-6.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: disable rate limiting when debug enabled btrfs: wait for fixup workers before stopping cleaner kthread during umount btrfs: fix a NULL pointer dereference when failed to start a new trasacntion btrfs: send: fix invalid clone operation for file that got its size decreased btrfs: tracepoints: end assignment with semicolon at btrfs_qgroup_extent event class btrfs: drop the backref cache during relocation if we commit btrfs: also add stripe entries for NOCOW writes btrfs: send: fix buffer overflow detection when copying path to cache entry
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-10-01btrfs: disable rate limiting when debug enabledLeo Martins
Disable ratelimiting for btrfs_printk when CONFIG_BTRFS_DEBUG is enabled. This allows for more verbose output which is often needed by functions like btrfs_dump_space_info(). Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Leo Martins <loemra.dev@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-01btrfs: wait for fixup workers before stopping cleaner kthread during umountFilipe Manana
During unmount, at close_ctree(), we have the following steps in this order: 1) Park the cleaner kthread - this doesn't destroy the kthread, it basically halts its execution (wake ups against it work but do nothing); 2) We stop the cleaner kthread - this results in freeing the respective struct task_struct; 3) We call btrfs_stop_all_workers() which waits for any jobs running in all the work queues and then free the work queues. Syzbot reported a case where a fixup worker resulted in a crash when doing a delayed iput on its inode while attempting to wake up the cleaner at btrfs_add_delayed_iput(), because the task_struct of the cleaner kthread was already freed. This can happen during unmount because we don't wait for any fixup workers still running before we call kthread_stop() against the cleaner kthread, which stops and free all its resources. Fix this by waiting for any fixup workers at close_ctree() before we call kthread_stop() against the cleaner and run pending delayed iputs. The stack traces reported by syzbot were the following: BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065 Read of size 8 at addr ffff8880272a8a18 by task kworker/u8:3/52 CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: btrfs-fixup btrfs_work_helper 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 __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4154 btrfs_writepage_fixup_worker+0xc16/0xdf0 fs/btrfs/inode.c:2842 btrfs_work_helper+0x390/0xc50 fs/btrfs/async-thread.c:314 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 2: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187 alloc_task_struct_node kernel/fork.c:180 [inline] dup_task_struct+0x57/0x8c0 kernel/fork.c:1107 copy_process+0x5d1/0x3d50 kernel/fork.c:2206 kernel_clone+0x223/0x880 kernel/fork.c:2787 kernel_thread+0x1bc/0x240 kernel/fork.c:2849 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:765 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 61: 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:2343 [inline] slab_free mm/slub.c:4580 [inline] kmem_cache_free+0x1a2/0x420 mm/slub.c:4682 put_task_struct include/linux/sched/task.h:144 [inline] delayed_put_task_struct+0x125/0x300 kernel/exit.c:228 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 __call_rcu_common kernel/rcu/tree.c:3086 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 context_switch kernel/sched/core.c:5318 [inline] __schedule+0x184b/0x4ae0 kernel/sched/core.c:6675 schedule_idle+0x56/0x90 kernel/sched/core.c:6793 do_idle+0x56a/0x5d0 kernel/sched/idle.c:354 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13e/0x147 The buggy address belongs to the object at ffff8880272a8000 which belongs to the cache task_struct of size 7424 The buggy address is located 2584 bytes inside of freed 7424-byte region [ffff8880272a8000, ffff8880272a9d00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x272a8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801bafa500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080040004 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801bafa500 dead000000000122 0000000000000000 head: 0000000000000000 0000000080040004 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea00009caa01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 71247381401, free_ts 71214998153 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3039/0x3180 mm/page_alloc.c:3457 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x120 mm/slub.c:2413 allocate_slab+0x5a/0x2f0 mm/slub.c:2579 new_slab mm/slub.c:2632 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] kmem_cache_alloc_node_noprof+0x1fe/0x320 mm/slub.c:4187 alloc_task_struct_node kernel/fork.c:180 [inline] dup_task_struct+0x57/0x8c0 kernel/fork.c:1107 copy_process+0x5d1/0x3d50 kernel/fork.c:2206 kernel_clone+0x223/0x880 kernel/fork.c:2787 kernel_thread+0x1bc/0x240 kernel/fork.c:2849 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:765 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 page last free pid 5230 tgid 5230 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcd0/0xf00 mm/page_alloc.c:2638 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 getname_flags+0xb7/0x540 fs/namei.c:139 do_sys_openat2+0xd2/0x1d0 fs/open.c:1409 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 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: ffff8880272a8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880272a8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880272a8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880272a8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880272a8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: syzbot+8aaf2df2ef0164ffe1fb@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/66fb36b1.050a0220.aab67.003b.GAE@google.com/ CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@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>
2024-10-01btrfs: fix a NULL pointer dereference when failed to start a new trasacntionQu Wenruo
[BUG] Syzbot reported a NULL pointer dereference with the following crash: FAULT_INJECTION: forcing a failure. start_transaction+0x830/0x1670 fs/btrfs/transaction.c:676 prepare_to_relocate+0x31f/0x4c0 fs/btrfs/relocation.c:3642 relocate_block_group+0x169/0xd20 fs/btrfs/relocation.c:3678 ... BTRFS info (device loop0): balance: ended with status: -12 Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cc: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000660-0x0000000000000667] RIP: 0010:btrfs_update_reloc_root+0x362/0xa80 fs/btrfs/relocation.c:926 Call Trace: <TASK> commit_fs_roots+0x2ee/0x720 fs/btrfs/transaction.c:1496 btrfs_commit_transaction+0xfaf/0x3740 fs/btrfs/transaction.c:2430 del_balance_item fs/btrfs/volumes.c:3678 [inline] reset_balance_state+0x25e/0x3c0 fs/btrfs/volumes.c:3742 btrfs_balance+0xead/0x10c0 fs/btrfs/volumes.c:4574 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 [CAUSE] The allocation failure happens at the start_transaction() inside prepare_to_relocate(), and during the error handling we call unset_reloc_control(), which makes fs_info->balance_ctl to be NULL. Then we continue the error path cleanup in btrfs_balance() by calling reset_balance_state() which will call del_balance_item() to fully delete the balance item in the root tree. However during the small window between set_reloc_contrl() and unset_reloc_control(), we can have a subvolume tree update and created a reloc_root for that subvolume. Then we go into the final btrfs_commit_transaction() of del_balance_item(), and into btrfs_update_reloc_root() inside commit_fs_roots(). That function checks if fs_info->reloc_ctl is in the merge_reloc_tree stage, but since fs_info->reloc_ctl is NULL, it results a NULL pointer dereference. [FIX] Just add extra check on fs_info->reloc_ctl inside btrfs_update_reloc_root(), before checking fs_info->reloc_ctl->merge_reloc_tree. That DEAD_RELOC_TREE handling is to prevent further modification to the reloc tree during merge stage, but since there is no reloc_ctl at all, we do not need to bother that. Reported-by: syzbot+283673dbc38527ef9f3d@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/66f6bfa7.050a0220.38ace9.0019.GAE@google.com/ CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-01btrfs: send: fix invalid clone operation for file that got its size decreasedFilipe Manana
During an incremental send we may end up sending an invalid clone operation, for the last extent of a file which ends at an unaligned offset that matches the final i_size of the file in the send snapshot, in case the file had its initial size (the size in the parent snapshot) decreased in the send snapshot. In this case the destination will fail to apply the clone operation because its end offset is not sector size aligned and it ends before the current size of the file. Sending the truncate operation always happens when we finish processing an inode, after we process all its extents (and xattrs, names, etc). So fix this by ensuring the file has a valid size before we send a clone operation for an unaligned extent that ends at the final i_size of the file. The size we truncate to matches the start offset of the clone range but it could be any value between that start offset and the final size of the file since the clone operation will expand the i_size if the current size is smaller than the end offset. The start offset of the range was chosen because it's always sector size aligned and avoids a truncation into the middle of a page, which results in dirtying the page due to filling part of it with zeroes and then making the clone operation at the receiver trigger IO. The following test reproduces the issue: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create a file with a size of 256K + 5 bytes, having two extents, one # with a size of 128K and another one with a size of 128K + 5 bytes. last_ext_size=$((128 * 1024 + 5)) xfs_io -f -d -c "pwrite -S 0xab -b 128K 0 128K" \ -c "pwrite -S 0xcd -b $last_ext_size 128K $last_ext_size" \ $MNT/foo # Another file which we will later clone foo into, but initially with # a larger size than foo. xfs_io -f -c "pwrite -S 0xef 0 1M" $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap1 # Now resize bar and clone foo into it. xfs_io -c "truncate 0" \ -c "reflink $MNT/foo" $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap2 rm -f /tmp/send-full /tmp/send-inc btrfs send -f /tmp/send-full $MNT/snap1 btrfs send -p $MNT/snap1 -f /tmp/send-inc $MNT/snap2 umount $MNT mkfs.btrfs -f $DEV mount $DEV $MNT btrfs receive -f /tmp/send-full $MNT btrfs receive -f /tmp/send-inc $MNT umount $MNT Running it before this patch: $ ./test.sh (...) At subvol snap1 At snapshot snap2 ERROR: failed to clone extents to bar: Invalid argument A test case for fstests will be sent soon. Reported-by: Ben Millwood <thebenmachine@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAJhrHS2z+WViO2h=ojYvBPDLsATwLbg+7JaNCyYomv0fUxEpQQ@mail.gmail.com/ Fixes: 46a6e10a1ab1 ("btrfs: send: allow cloning non-aligned extent if it ends at i_size") CC: stable@vger.kernel.org # 6.11 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>