- 29 Oct, 2021 2 commits
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David Sterba authored
This reverts commit 696ab562. The kmaps in compression code are still needed and cause crashes on 32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004 with enabled LZO or ZSTD compression. Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Signed-off-by:
David Sterba <dsterba@suse.com>
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David Sterba authored
This reverts commit bbaf9715. The kmaps in compression code are still needed and cause crashes on 32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004 with enabled LZO or ZSTD compression. Example stacktrace with ZSTD on a 32bit ARM machine: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c4159ed3 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 210 Comm: kworker/u2:3 Not tainted 5.14.0-rc79+ #12 Hardware name: Allwinner sun4i/sun5i Families Workqueue: btrfs-delalloc btrfs_work_helper PC is at mmiocpy+0x48/0x330 LR is at ZSTD_compressStream_generic+0x15c/0x28c (mmiocpy) from [<c0629648>] (ZSTD_compressStream_generic+0x15c/0x28c) (ZSTD_compressStream_generic) from [<c06297dc>] (ZSTD_compressStream+0x64/0xa0) (ZSTD_compressStream) from [<c049444c>] (zstd_compress_pages+0x170/0x488) (zstd_compress_pages) from [<c0496798>] (btrfs_compress_pages+0x124/0x12c) (btrfs_compress_pages) from [<c043c068>] (compress_file_range+0x3c0/0x834) (compress_file_range) from [<c043c4ec>] (async_cow_start+0x10/0x28) (async_cow_start) from [<c0475c3c>] (btrfs_work_helper+0x100/0x230) (btrfs_work_helper) from [<c014ef68>] (process_one_work+0x1b4/0x418) (process_one_work) from [<c014f210>] (worker_thread+0x44/0x524) (worker_thread) from [<c0156aa4>] (kthread+0x180/0x1b0) (kthread) from [<c0100150>] Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Signed-off-by:
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- 27 Oct, 2021 1 commit
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David Sterba authored
This reverts commit 4c2bf276. The kmaps in compression code are still needed and cause crashes on 32bit machines (ARM, x86). Reproducible eg. by running fstest btrfs/004 with enabled LZO or ZSTD compression. Link: https://lore.kernel.org/all/CAJCQCtT+OuemovPO7GZk8Y8=qtOObr0XTDp8jh4OHD6y84AFxw@mail.gmail.com/ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=214839Signed-off-by:
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- 07 Oct, 2021 8 commits
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Josef Bacik authored
Error injection testing uncovered a case where we'd end up with a corrupt file system with a missing extent in the middle of a file. This occurs because the if statement to decide if we should abort is wrong. The only way we would abort in this case is if we got a ret != -EOPNOTSUPP and we called from the file clone code. However the prealloc code uses this path too. Instead we need to abort if there is an error, and the only error we _don't_ abort on is -EOPNOTSUPP and only if we came from the clone file code. CC: stable@vger.kernel.org # 5.10+ Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Reviewed-by:
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Filipe Manana authored
At replay_one_name(), we are treating any error from btrfs_lookup_inode() as if the inode does not exists. Fix this by checking for an error and returning it to the caller. CC: stable@vger.kernel.org # 4.14+ Signed-off-by:
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Filipe Manana authored
btrfs_lookup_dir_index_item() and btrfs_lookup_dir_item() lookup for dir entries and both are used during log replay or when updating a log tree during an unlink. However when the dir item does not exists, btrfs_lookup_dir_item() returns NULL while btrfs_lookup_dir_index_item() returns PTR_ERR(-ENOENT), and if the dir item exists but there is no matching entry for a given name or index, both return NULL. This makes the call sites during log replay to be more verbose than necessary and it makes it easy to miss this slight difference. Since we don't need to distinguish between those two cases, make btrfs_lookup_dir_index_item() always return NULL when there is no matching directory entry - either because there isn't any dir entry or because there is one but it does not match the given name and index. Also rename the argument 'objectid' of btrfs_lookup_dir_index_item() to 'index' since it is supposed to match an index number, and the name 'objectid' is not very good because it can easily be confused with an inode number (like the inode number a dir entry points to). CC: stable@vger.kernel.org # 4.14+ Signed-off-by:
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Filipe Manana authored
At __inode_add_ref(), we treating any error returned from btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning that there is no existing directory entry in the fs/subvolume tree. This is not correct since we can get errors such as, for example, -EIO when reading extent buffers while searching the fs/subvolume's btree. So fix that and return the error to the caller when it is not -ENOENT. CC: stable@vger.kernel.org # 4.14+ Signed-off-by:
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Filipe Manana authored
At replay_one_one(), we are treating any error returned from btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning that there is no existing directory entry in the fs/subvolume tree. This is not correct since we can get errors such as, for example, -EIO when reading extent buffers while searching the fs/subvolume's btree. So fix that and return the error to the caller when it is not -ENOENT. CC: stable@vger.kernel.org # 4.14+ Signed-off-by:
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Filipe Manana authored
Currently inode_in_dir() ignores errors returned from btrfs_lookup_dir_index_item() and from btrfs_lookup_dir_item(), treating any errors as if the directory entry does not exists in the fs/subvolume tree, which is obviously not correct, as we can get errors such as -EIO when reading extent buffers while searching the fs/subvolume's tree. Fix that by making inode_in_dir() return the errors and making its only caller, add_inode_ref(), deal with returned errors as well. Signed-off-by:
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Josef Bacik authored
I hit a stuck relocation on btrfs/061 during my overnight testing. This turned out to be because we had left over extent entries in our extent root for a data reloc inode that no longer existed. This happened because in btrfs_drop_extents() we only update refs if we have SHAREABLE set or we are the tree_root. This regression was introduced by aeb935a4 ("btrfs: don't set SHAREABLE flag for data reloc tree") where we stopped setting SHAREABLE for the data reloc tree. The problem here is we actually do want to update extent references for data extents in the data reloc tree, in fact we only don't want to update extent references if the file extents are in the log tree. Update this check to only skip updating references in the case of the log tree. This is relatively rare, because you have to be running scrub at the same time, which is what btrfs/061 does. The data reloc inode has its extents pre-allocated, and then we copy the extent into the pre-allocated chunks. We theoretically should never be calling btrfs_drop_extents() on a data reloc inode. The exception of course is with scrub, if our pre-allocated extent falls inside of the block group we are scrubbing, then the block group will be marked read only and we will be forced to cow that extent. This means we will call btrfs_drop_extents() on that range when we COW that file extent. This isn't really problematic if we do this, the data reloc inode requires that our extent lengths match exactly with the extent we are copying, thankfully we validate the extent is correct with get_new_location(), so if we happen to COW only part of the extent we won't link it in when we do the relocation, so we are safe from any other shenanigans that arise because of this interaction with scrub. Fixes: aeb935a4 ("btrfs: don't set SHAREABLE flag for data reloc tree") CC: stable@vger.kernel.org # 5.8+ Reviewed-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
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Qu Wenruo authored
[BUG] There is a bug report that injected ENOMEM error could leave a tree block locked while we return to user-space: BTRFS info (device loop0): enabling ssd optimizations FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 7579 Comm: syz-executor Not tainted 5.15.0-rc1 #16 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x13c/0x160 lib/fault-inject.c:146 should_failslab+0x5/0x10 mm/slab_common.c:1328 slab_pre_alloc_hook.constprop.99+0x4e/0xc0 mm/slab.h:494 slab_alloc_node mm/slub.c:3120 [inline] slab_alloc mm/slub.c:3214 [inline] kmem_cache_alloc+0x44/0x280 mm/slub.c:3219 btrfs_alloc_delayed_extent_op fs/btrfs/delayed-ref.h:299 [inline] btrfs_alloc_tree_block+0x38c/0x670 fs/btrfs/extent-tree.c:4833 __btrfs_cow_block+0x16f/0x7d0 fs/btrfs/ctree.c:415 btrfs_cow_block+0x12a/0x300 fs/btrfs/ctree.c:570 btrfs_search_slot+0x6b0/0xee0 fs/btrfs/ctree.c:1768 btrfs_insert_empty_items+0x80/0xf0 fs/btrfs/ctree.c:3905 btrfs_new_inode+0x311/0xa60 fs/btrfs/inode.c:6530 btrfs_create+0x12b/0x270 fs/btrfs/inode.c:6783 lookup_open+0x660/0x780 fs/namei.c:3282 open_last_lookups fs/namei.c:3352 [inline] path_openat+0x465/0xe20 fs/namei.c:3557 do_filp_open+0xe3/0x170 fs/namei.c:3588 do_sys_openat2+0x357/0x4a0 fs/open.c:1200 do_sys_open+0x87/0xd0 fs/open.c:1216 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x46ae99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f46711b9c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 000000000078c0a0 RCX: 000000000046ae99 RDX: 0000000000000000 RSI: 00000000000000a1 RDI: 0000000020005800 RBP: 00007f46711b9c80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000017 R13: 0000000000000000 R14: 000000000078c0a0 R15: 00007ffc129da6e0 ================================================ WARNING: lock held when returning to user space! 5.15.0-rc1 #16 Not tainted ------------------------------------------------ syz-executor/7579 is leaving the kernel with locks still held! 1 lock held by syz-executor/7579: #0: ffff888104b73da8 (btrfs-tree-01/1){+.+.}-{3:3}, at: __btrfs_tree_lock+0x2e/0x1a0 fs/btrfs/locking.c:112 [CAUSE] In btrfs_alloc_tree_block(), after btrfs_init_new_buffer(), the new extent buffer @buf is locked, but if later operations like adding delayed tree ref fail, we just free @buf without unlocking it, resulting above warning. [FIX] Unlock @buf in out_free_buf: label. Reported-by:Hao Sun <sunhao.th@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CACkBjsZ9O6Zr0KK1yGn=1rQi6Crh1yeCRdTSBxx9R99L4xdn-Q@mail.gmail.com/ CC: stable@vger.kernel.org # 5.4+ Signed-off-by:
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- 17 Sep, 2021 4 commits
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Qu Wenruo authored
It's not uncommon where __btrfs_dump_space_info() gets called under over-commit situations. In that case free space would underflow as total allocated space is not enough to handle all the over-committed space. Such underflow values can sometimes cause confusion for users enabled enospc_debug mount option, and takes some seconds for developers to convert the underflow value to signed result. Just output the free space as s64 to avoid such problem. Reported-by:
Eli V <eliventer@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/ CC: stable@vger.kernel.org # 5.4+ Reviewed-by:
Anand Jain <anand.jain@oracle.com> Signed-off-by:
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Filipe Manana authored
When we get an error flushing one device, during a super block commit, we record the error in the device structure, in the field 'last_flush_error'. This is used to later check if we should error out the super block commit, depending on whether the number of flush errors is greater than or equals to the maximum tolerated device failures for a raid profile. However if we get a transient device flush error, unmount the filesystem and later try to mount it, we can fail the mount because we treat that past error as critical and consider the device is missing. Even if it's very likely that the error will happen again, as it's probably due to a hardware related problem, there may be cases where the error might not happen again. One example is during testing, and a test case like the new generic/648 from fstests always triggers this. The test cases generic/019 and generic/475 also trigger this scenario, but very sporadically. When this happens we get an error like this: $ mount /dev/sdc /mnt mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error. $ dmesg (...) [12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount [12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices [12918.890853] BTRFS error (device sdc): open_ctree failed The failure happens because when btrfs_check_rw_degradable() is called at mount time, or at remount from RO to RW time, is sees a non zero value in a device's ->last_flush_error attribute, and therefore considers that the device is 'missing'. Fix this by setting a device's ->last_flush_error to zero when we close a device, making sure the error is not seen on the next mount attempt. We only need to track flush errors during the current mount, so that we never commit a super block if such errors happened. Signed-off-by:
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Filipe Manana authored
During a verity rollback, if we fail to update the inode or delete the orphan, we abort the transaction and return without releasing our transaction handle. Fix that by releasing the handle. Fixes: 14605409 ("btrfs: initial fsverity support") Fixes: 70524253 ("btrfs: verity metadata orphan items") Reviewed-by:
Boris Burkov <boris@bur.io> Signed-off-by:
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Qu Wenruo authored
There is a BUG_ON() in btrfs_csum_one_bio() to catch code logic error. It has indeed caught several bugs during subpage development. But the BUG_ON() itself will bring down the whole system which is an overkill. Replace it with a WARN() and exit gracefully, so that it won't crash the whole system while we can still catch the code logic error. Signed-off-by:
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- 07 Sep, 2021 6 commits
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Naohiro Aota authored
btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes. Then, splitting an ordered extent will call btrfs_add_ordered_extent_*() again for split extents, leading to double counting of the region of a split extent. These leaked bytes are finally reported at unmount time as follow: BTRFS info (device dm-1): at unmount dio bytes count 364544 Fix the double counting by subtracting split extent's size from fs_info->ordered_bytes. Fixes: d22002fd ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by:
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Anand Jain authored
Following test case reproduces lockdep warning. Test case: $ mkfs.btrfs -f <dev1> $ btrfstune -S 1 <dev1> $ mount <dev1> <mnt> $ btrfs device add <dev2> <mnt> -f $ umount <mnt> $ mount <dev2> <mnt> $ umount <mnt> The warning claims a possible ABBA deadlock between the threads initiated by [#1] btrfs device add and [#0] the mount. [ 540.743122] WARNING: possible circular locking dependency detected [ 540.743129] 5.11.0-rc7+ #5 Not tainted [ 540.743135] ------------------------------------------------------ [ 540.743142] mount/2515 is trying to acquire lock: [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs] [ 540.743458] but task is already holding lock: [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743541] which lock already depends on the new lock. [ 540.743543] the existing dependency chain (in reverse order) is: [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}: [ 540.743566] down_read_nested+0x48/0x2b0 [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs] [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs] [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs] [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs] [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs] [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs] [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs] [ 540.744166] __x64_sys_ioctl+0xe4/0x140 [ 540.744170] do_syscall_64+0x4b/0x80 [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}: [ 540.744184] __lock_acquire+0x155f/0x2360 [ 540.744188] lock_acquire+0x10b/0x5c0 [ 540.744190] __mutex_lock+0xb1/0xf80 [ 540.744193] mutex_lock_nested+0x27/0x30 [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs] [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs] [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs] [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs] [ 540.744472] legacy_get_tree+0x38/0x90 [ 540.744475] vfs_get_tree+0x30/0x140 [ 540.744478] fc_mount+0x16/0x60 [ 540.744482] vfs_kern_mount+0x91/0x100 [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs] [ 540.744536] legacy_get_tree+0x38/0x90 [ 540.744537] vfs_get_tree+0x30/0x140 [ 540.744539] path_mount+0x8d8/0x1070 [ 540.744541] do_mount+0x8d/0xc0 [ 540.744543] __x64_sys_mount+0x125/0x160 [ 540.744545] do_syscall_64+0x4b/0x80 [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744551] other info that might help us debug this: [ 540.744552] Possible unsafe locking scenario: [ 540.744553] CPU0 CPU1 [ 540.744554] ---- ---- [ 540.744555] lock(btrfs-chunk-00); [ 540.744557] lock(&fs_devs->device_list_mutex); [ 540.744560] lock(btrfs-chunk-00); [ 540.744562] lock(&fs_devs->device_list_mutex); [ 540.744564] *** DEADLOCK *** [ 540.744565] 3 locks held by mount/2515: [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450 [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs] [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.744708] stack backtrace: [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5 But the device_list_mutex in clone_fs_devices() is redundant, as explained below. Two threads [1] and [2] (below) could lead to clone_fs_device(). [1] open_ctree <== mount sprout fs btrfs_read_chunk_tree() mutex_lock(&uuid_mutex) <== global lock read_one_dev() open_seed_devices() clone_fs_devices() <== seed fs_devices mutex_lock(&orig->device_list_mutex) <== seed fs_devices [2] btrfs_init_new_device() <== sprouting mutex_lock(&uuid_mutex); <== global lock btrfs_prepare_sprout() lockdep_assert_held(&uuid_mutex) clone_fs_devices(seed_fs_device) <== seed fs_devices Both of these threads hold uuid_mutex which is sufficient to protect getting the seed device(s) freed while we are trying to clone it for sprouting [2] or mounting a sprout [1] (as above). A mounted seed device can not free/write/replace because it is read-only. An unmounted seed device can be freed by btrfs_free_stale_devices(), but it needs uuid_mutex. So this patch removes the unnecessary device_list_mutex in clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in clone_fs_devices(). Reported-by:Su Yue <l@damenly.su> Tested-by:
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Josef Bacik authored
When removing the device we call blkdev_put() on the device once we've removed it, and because we have an EXCL open we need to take the ->open_mutex on the block device to clean it up. Unfortunately during device remove we are holding the sb writers lock, which results in the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #407 Not tainted ------------------------------------------------------ losetup/11595 is trying to acquire lock: ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_put+0x3a/0x220 btrfs_rm_device.cold+0x62/0xe5 btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11595: #0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc21255d4cb So instead save the bdev and do the put once we've dropped the sb writers lock in order to avoid the lockdep recursion. Reviewed-by: -
Josef Bacik authored
We update the ctime/mtime of a block device when we remove it so that blkid knows the device changed. However we do this by re-opening the block device and calling filp_update_time. This is more correct because it'll call the inode->i_op->update_time if it exists, but the block dev inodes do not do this. Instead call generic_update_time() on the bd_inode in order to avoid the blkdev_open path and get rid of the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #406 Not tainted ------------------------------------------------------ losetup/11596 is trying to acquire lock: ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_get_by_dev.part.0+0x56/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 file_open_name+0xc7/0x170 filp_open+0x2c/0x50 btrfs_scratch_superblocks.part.0+0x10f/0x170 btrfs_rm_device.cold+0xe8/0xed btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11596: #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Reviewed-by: -
Kari Argillander authored
asm/do_div.h is for div_u64, but it is found in math64.h. This change will make compiler job easier and prevent compiler errors in situation where compiler will not find math64.h from another paths. Signed-off-by:
Kari Argillander <kari.argillander@gmail.com> Reviewed-by:
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Anand Jain authored
The mount option max_inline ranges from 0 to the sectorsize (which is now equal to page size). But we parse the mount options too early and before the actual sectorsize is read from the superblock. So the upper limit of max_inline is unaware of the actual sectorsize and is limited by the temporary sectorsize 4096, even on a system where the default sectorsize is 64K. Fix this by reading the superblock sectorsize before the mount option parse. Reported-by:
Alexander Tsvetkov <alexander.tsvetkov@oracle.com> CC: stable@vger.kernel.org # 5.4+ Signed-off-by:
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- 23 Aug, 2021 19 commits
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Desmond Cheong Zhi Xi authored
This crash was observed with a failed assertion on device close: BTRFS: Transaction aborted (error -28) WARNING: CPU: 1 PID: 3902 at fs/btrfs/extent-tree.c:2150 btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] Modules linked in: btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop CPU: 1 PID: 3902 Comm: kworker/u8:4 Not tainted 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] RIP: 0010:btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] RSP: 0018:ffffb7a5452d7d80 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff97834176a378 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff97835195d388 R13: 0000000005b08000 R14: ffff978385484000 R15: 000000000000016c FS: 0000000000000000(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190d003fe8 CR3: 000000002a81e005 CR4: 0000000000170ea0 Call Trace: flush_space+0x197/0x2f0 [btrfs] btrfs_async_reclaim_metadata_space+0x139/0x300 [btrfs] process_one_work+0x262/0x5e0 worker_thread+0x4c/0x320 ? process_one_work+0x5e0/0x5e0 kthread+0x144/0x170 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 irq event stamp: 19334989 hardirqs last enabled at (19334997): [<ffffffffab0e0c87>] console_unlock+0x2b7/0x400 hardirqs last disabled at (19335006): [<ffffffffab0e0d0d>] console_unlock+0x33d/0x400 softirqs last enabled at (19334900): [<ffffffffaba0030d>] __do_softirq+0x30d/0x574 softirqs last disabled at (19334893): [<ffffffffab0721ec>] irq_exit_rcu+0x12c/0x140 ---[ end trace 45939e308e0dd3c7 ]--- BTRFS: error (device vdd) in btrfs_run_delayed_refs:2150: errno=-28 No space left BTRFS info (device vdd): forced readonly BTRFS warning (device vdd): failed setting block group ro: -30 BTRFS info (device vdd): suspending dev_replace for unmount assertion failed: !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state), in fs/btrfs/volumes.c:1150 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.h:3431! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 3982 Comm: umount Tainted: G W 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs] RSP: 0018:ffffb7a5454c7db8 EFLAGS: 00010246 RAX: 0000000000000068 RBX: ffff978364b91c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff9783523a4c00 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff9783523a4d18 R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000003 FS: 00007f61c8f42800(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190cffa810 CR3: 0000000030b96002 CR4: 0000000000170ea0 Call Trace: btrfs_close_one_device.cold+0x11/0x55 [btrfs] close_fs_devices+0x44/0xb0 [btrfs] btrfs_close_devices+0x48/0x160 [btrfs] generic_shutdown_super+0x69/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x2c/0xa0 cleanup_mnt+0x144/0x1b0 task_work_run+0x59/0xa0 exit_to_user_mode_loop+0xe7/0xf0 exit_to_user_mode_prepare+0xaf/0xf0 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x4a/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae This happens when close_ctree is called while a dev_replace hasn't completed. In close_ctree, we suspend the dev_replace, but keep the replace target around so that we can resume the dev_replace procedure when we mount the root again. This is the call trace: close_ctree(): btrfs_dev_replace_suspend_for_unmount(); btrfs_close_devices(): btrfs_close_fs_devices(): btrfs_close_one_device(): ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); However, since the replace target sticks around, there is a device with BTRFS_DEV_STATE_REPLACE_TGT set on close, and we fail the assertion in btrfs_close_one_device. To fix this, if we come across the replace target device when closing, we should properly reset it back to allocation state. This fix also ensures that if a non-target device has a corrupted state and has the BTRFS_DEV_STATE_REPLACE_TGT bit set, the assertion will still catch the error. Reported-by:Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> Reviewed-by:
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Naohiro Aota authored
btrfs_lookup_ordered_extent() is supposed to query the offset in a file instead of the logical address. Pass the file offset from submit_extent_page() to calc_bio_boundaries(). Also, calc_bio_boundaries() relies on the bio's operation flag, so move the call site after setting it. Fixes: 390ed29b ("btrfs: refactor submit_extent_page() to make bio and its flag tracing easier") Reviewed-by:
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Josef Bacik authored
A common characteristic of the bug report where preemptive flushing was going full tilt was the fact that the vast majority of the free metadata space was used up by the global reserve. The hard 90% threshold would cover the majority of these cases, but to be even smarter we should take into account how much of the outstanding reservations are covered by the global block reserve. If the global block reserve accounts for the vast majority of outstanding reservations, skip preemptive flushing, as it will likely just cause churn and pain. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212185Signed-off-by:
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Josef Bacik authored
The preemptive flushing code was added in order to avoid needing to synchronously wait for ENOSPC flushing to recover space. Once we're almost full however we can essentially flush constantly. We were using 98% as a threshold to determine if we were simply full, however in practice this is a really high bar to hit. For example reports of systems running into this problem had around 94% usage and thus continued to flush. Fix this by lowering the threshold to 90%, which is a more sane value, especially for smaller file systems. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212185 CC: stable@vger.kernel.org # 5.12+ Fixes: 576fa348 ("btrfs: improve preemptive background space flushing") Signed-off-by:
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Marcos Paulo de Souza authored
Function btrfs_lookup_data_extent calls btrfs_search_slot to verify if the EXTENT_ITEM exists in the extent tree. btrfs_search_slot can return values bellow zero if an error happened. Function replay_one_extent currently checks if the search found something (0 returned) and increments the reference, and if not, it seems to evaluate as 'not found'. Fix the condition by checking if the value was bellow zero and return early. Reviewed-by:
Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by:
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Filipe Manana authored
There are several cases where when logging an inode we need to log its parent directories or logging subdirectories when logging a directory. There are cases however where we end up logging a directory even if it was not changed in the current transaction, no dentries added or removed since the last transaction. While this is harmless from a functional point of view, it is a waste time as it brings no advantage. One example where this is triggered is the following: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/C $ touch /mnt/A/foo $ ln /mnt/A/foo /mnt/B/bar $ ln /mnt/A/foo /mnt/C/baz $ sync $ rm -f /mnt/A/foo $ xfs_io -c "fsync" /mnt/B/bar This last fsync ends up logging directories A, B and C, however we only need to log directory A, as B and C were not changed since the last transaction commit. So fix this by changing need_log_inode(), to return false in case the given inode is a directory and has a ->last_trans value smaller than the current transaction's ID. Signed-off-by:
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Christian Brauner authored
Now that we converted btrfs internally to account for idmapped mounts allow the creation of idmapped mounts on by setting the FS_ALLOW_IDMAP flag. We only need to raise this flag on the btrfs_root_fs_type filesystem since btrfs_mount_root() is ultimately responsible for allocating the superblock and is called into from btrfs_mount() associated with btrfs_fs_type. The conversion of the btrfs inode operations was straightforward. Regarding btrfs specific ioctls that perform checks based on inode permissions only those have been allowed that are not filesystem wide operations and hence can be reasonably charged against a specific mount. Reviewed-by:
Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by:
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Christian Brauner authored
Make the ACL code idmapped mount aware. The POSIX default and POSIX access ACLs are the only ACLs other than some specific xattrs that take DAC permissions into account. On an idmapped mount they need to be translated according to the mount's userns. The main change is done to __btrfs_set_acl() which is responsible for translating POSIX ACLs to their final on-disk representation. The btrfs_init_acl() helper does not need to take the idmapped mount into account since it is called in the context of file creation operations (mknod, create, mkdir, symlink, tmpfile) and is used for btrfs_init_inode_security() to copy POSIX default and POSIX access permissions from the parent directory. These ACLs need to be inherited unmodified from the parent directory. This is identical to what we do for ext4 and xfs. Reviewed-by:
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Christian Brauner authored
The INO_LOOKUP_USER is an unprivileged version of the INO_LOOKUP ioctl and has the following restrictions. The main difference between the two is that INO_LOOKUP is filesystem wide operation wheres INO_LOOKUP_USER is scoped beneath the file descriptor passed with the ioctl. Specifically, INO_LOOKUP_USER must adhere to the following restrictions: - The caller must be privileged over each inode of each path component for the path they are trying to lookup. - The path for the subvolume the caller is trying to lookup must be reachable from the inode associated with the file descriptor passed with the ioctl. The second condition makes it possible to scope the lookup of the path to the mount identified by the file descriptor passed with the ioctl. This allows us to enable this ioctl on idmapped mounts. Specifically, this is possible because all child subvolumes of a parent subvolume are reachable when the parent subvolume is mounted. So if the user had access to open the parent subvolume or has been given the fd then they can lookup the path if they had access to it provided they were privileged over each path component. Note, the INO_LOOKUP_USER ioctl allows a user to learn the path and name of a subvolume even though they would otherwise be restricted from doing so via regular VFS-based lookup. So think about a parent subvolume with multiple child subvolumes. Someone could mount he parent subvolume and restrict access to the child subvolumes by overmounting them with empty directories. At this point the user can't traverse the child subvolumes and they can't open files in the child subvolumes. However, they can still learn the path of child subvolumes as long as they have access to the parent subvolume by using the INO_LOOKUP_USER ioctl. The underlying assumption here is that it's ok that the lookup ioctls can't really take mounts into account other than the original mount the fd belongs to during lookup. Since this assumption is baked into the original INO_LOOKUP_USER ioctl we can extend it to idmapped mounts. Reviewed-by:
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Christian Brauner authored
Setting flags on subvolumes or snapshots are core features of btrfs. The SUBVOL_SETFLAGS ioctl is especially important as it allows to make subvolumes and snapshots read-only or read-write. Allow setting flags on btrfs subvolumes and snapshots on idmapped mounts. This is a fairly straightforward operation since all the permission checking helpers are already capable of handling idmapped mounts. So we just need to pass down the mount's userns. Reviewed-by:
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Christian Brauner authored
The SET_RECEIVED_SUBVOL ioctls are used to set information about a received subvolume. Make it possible to set information about a received subvolume on idmapped mounts. This is a fairly straightforward operation since all the permission checking helpers are already capable of handling idmapped mounts. So we just need to pass down the mount's userns. Reviewed-by:
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Christian Brauner authored
So far we prevented the deletion of subvolumes and snapshots using subvolume ids possible with the BTRFS_SUBVOL_SPEC_BY_ID flag. This restriction is necessary on idmapped mounts as this allows filesystem wide subvolume and snapshot deletions and thus can escape the scope of what's exposed under the mount identified by the fd passed with the ioctl. Deletion by subvolume id works by looking for an alias of the parent of the subvolume or snapshot to be deleted. The parent alias can be anywhere in the filesystem. However, as long as the alias of the parent that is found is the same as the one identified by the file descriptor passed through the ioctl we can allow the deletion. Reviewed-by:
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Christian Brauner authored
Destroying subvolumes and snapshots are important features of btrfs. Both operations are available to unprivileged users if the filesystem has been mounted with the "user_subvol_rm_allowed" mount option. Allow subvolume and snapshot deletion on idmapped mounts. This is a fairly straightforward operation since all the permission checking helpers are already capable of handling idmapped mounts. So we just need to pass down the mount's userns. Subvolumes and snapshots can either be deleted by specifying their name or - if BTRFS_IOC_SNAP_DESTROY_V2 is used - by their subvolume or snapshot id if the BTRFS_SUBVOL_SPEC_BY_ID is set. This feature is blocked on idmapped mounts as this allows filesystem wide subvolume deletions and thus can escape the scope of what's exposed under the mount identified by the fd passed with the ioctl. This means that even the root or CAP_SYS_ADMIN capable user can't delete a subvolume via BTRFS_SUBVOL_SPEC_BY_ID. This is intentional. The root user is currently already subject to permission checks in btrfs_may_delete() including whether the inode's i_uid/i_gid of the directory the subvolume is located in have a mapping in the caller's idmapping. For this to fail isn't currently possible since a btrfs filesystem can't be mounted with a non-initial idmapping but it shows that even the root user would fail to delete a subvolume if the relevant inode isn't mapped in their idmapping. The idmapped mount case is the same in principle. This isn't a huge problem a root user wanting to delete arbitrary subvolumes can just always create another (even detached) mount without an idmapping attached. In addition, we will allow BTRFS_SUBVOL_SPEC_BY_ID for cases where the subvolume to delete is directly located under inode referenced by the fd passed for the ioctl() in a follow-up commit. Here is an example where a btrfs subvolume is deleted through a subvolume mount that does not expose the subvolume to be delete but it can still be deleted by using the subvolume id: /* Compile the following program as "delete_by_spec". */ #define _GNU_SOURCE #include <fcntl.h> #include <inttypes.h> #include <linux/btrfs.h> #include <stdio.h> #include <stdlib.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> static int rm_subvolume_by_id(int fd, uint64_t subvolid) { struct btrfs_ioctl_vol_args_v2 args = {}; int ret; args.flags = BTRFS_SUBVOL_SPEC_BY_ID; args.subvolid = subvolid; ret = ioctl(fd, BTRFS_IOC_SNAP_DESTROY_V2, &args); if (ret < 0) return -1; return 0; } int main(int argc, char *argv[]) { int subvolid = 0; if (argc < 3) exit(1); fprintf(stderr, "Opening %s\n", argv[1]); int fd = open(argv[1], O_CLOEXEC | O_DIRECTORY); if (fd < 0) exit(2); subvolid = atoi(argv[2]); fprintf(stderr, "Deleting subvolume with subvolid %d\n", subvolid); int ret = rm_subvolume_by_id(fd, subvolid); if (ret < 0) exit(3); exit(0); } #include <stdio.h>" #include <stdlib.h>" #include <linux/btrfs.h" truncate -s 10G btrfs.img mkfs.btrfs btrfs.img export LOOPDEV=$(sudo losetup -f --show btrfs.img) mount ${LOOPDEV} /mnt sudo chown $(id -u):$(id -g) /mnt btrfs subvolume create /mnt/A btrfs subvolume create /mnt/B/C # Get subvolume id via: sudo btrfs subvolume show /mnt/A # Save subvolid SUBVOLID=<nr> sudo umount /mnt sudo mount ${LOOPDEV} -o subvol=B/C,user_subvol_rm_allowed /mnt ./delete_by_spec /mnt ${SUBVOLID} With idmapped mounts this can potentially be used by users to delete subvolumes/snapshots they would otherwise not have access to as the idmapping would be applied to an inode that is not exposed in the mount of the subvolume. The fact that this is a filesystem wide operation suggests it might be a good idea to expose this under a separate ioctl that clearly indicates this. In essence, the file descriptor passed with the ioctl is merely used to identify the filesystem on which to operate when BTRFS_SUBVOL_SPEC_BY_ID is used. Reviewed-by: -
Christian Brauner authored
Creating subvolumes and snapshots is one of the core features of btrfs and is even available to unprivileged users. Make it possible to use subvolume and snapshot creation on idmapped mounts. This is a fairly straightforward operation since all the permission checking helpers are already capable of handling idmapped mounts. So we just need to pass down the mount's userns. Reviewed-by:
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Christian Brauner authored
When a new subvolume is created btrfs currently doesn't check whether the fsgid/fsuid of the caller actually have a mapping in the user namespace attached to the filesystem. The VFS always checks this to make sure that the caller's fsgid/fsuid can be represented on-disk. This is most relevant for filesystems that can be mounted inside user namespaces but it is in general a good hardening measure to prevent unrepresentable gid/uid from being written to disk. Since we want to support idmapped mounts for btrfs ioctls to create subvolumes in follow-up patches this becomes important since we want to make sure the fsgid/fsuid of the caller as mapped according to the idmapped mount can be represented on-disk. Simply add the missing fsuidgid_has_mapping() line from the VFS may_create() version to btrfs_may_create(). Reviewed-by:
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Christian Brauner authored
Enable btrfs_permission() to handle idmapped mounts. This is just a matter of passing down the mount's userns. Reviewed-by:
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Christian Brauner authored
Enable btrfs_setattr() to handle idmapped mounts. This is just a matter of passing down the mount's userns. Reviewed-by:
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Christian Brauner authored
Enable btrfs_tmpfile() to handle idmapped mounts. This is just a matter of passing down the mount's userns. Reviewed-by:
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Christian Brauner authored
Enable btrfs_symlink() to handle idmapped mounts. This is just a matter of passing down the mount's userns. Reviewed-by:
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