- 29 Jul, 2021 1 commit
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David Sterba authored
Building with -Warray-bounds on systems with 64K pages there's a warning: fs/btrfs/disk-io.c: In function ‘csum_tree_block’: fs/btrfs/disk-io.c:226:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] 226 | kaddr = page_address(buf->pages[i]); | ~~~~~~~~~~^~~ ./include/linux/mm.h:1630:48: note: in definition of macro ‘page_address’ 1630 | #define page_address(page) lowmem_page_address(page) | ^~~~ In file included from fs/btrfs/ctree.h:32, from fs/btrfs/disk-io.c:23: fs/btrfs/extent_io.h:98:15: note: while referencing ‘pages’ 98 | struct page *pages[1]; | ^~~~~ The compiler has no way to know that in that case the nodesize is exactly PAGE_SIZE, so the resulting number of pages will be correct (1). Let's use num_extent_pages that makes the case nodesize == PAGE_SIZE explicitly 1. Reported-by:Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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- 28 Jul, 2021 3 commits
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Desmond Cheong Zhi Xi authored
When removing a writeable device in __btrfs_free_extra_devids, the rw device count should be decremented. This error was caught by Syzbot which reported a warning in close_fs_devices: WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 Modules linked in: CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293 RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128 R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180 open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693 btrfs_fill_super fs/btrfs/super.c:1382 [inline] btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 fc_mount fs/namespace.c:993 [inline] vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023 btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Because fs_devices->rw_devices was not 0 after closing all devices. Here is the call trace that was observed: btrfs_mount_root(): btrfs_scan_one_device(): device_list_add(); <---------------- device added btrfs_open_devices(): open_fs_devices(): btrfs_open_one_device(); <-------- writable device opened, rw device count ++ btrfs_fill_super(): open_ctree(): btrfs_free_extra_devids(): __btrfs_free_extra_devids(); <--- writable device removed, rw device count not decremented fail_tree_roots: btrfs_close_devices(): close_fs_devices(); <------- rw device count off by 1 As a note, prior to commit cf89af14 ("btrfs: dev-replace: fail mount if we don't have replace item with target device"), rw_devices was decremented on removing a writable device in __btrfs_free_extra_devids only if the BTRFS_DEV_STATE_REPLACE_TGT bit was not set for the device. However, this check does not need to be reinstated as it is now redundant and incorrect. In __btrfs_free_extra_devids, we skip removing the device if it is the target for replacement. This is done by checking whether device->devid == BTRFS_DEV_REPLACE_DEVID. Since BTRFS_DEV_STATE_REPLACE_TGT is set only on the device with devid BTRFS_DEV_REPLACE_DEVID, no devices should have the BTRFS_DEV_STATE_REPLACE_TGT bit set after the check, and so it's redundant to test for that bit. Additionally, following commit 82372bc8 ("Btrfs: make the logic of source device removing more clear"), rw_devices is incremented whenever a writeable device is added to the alloc list (including the target device in btrfs_dev_replace_finishing), so all removals of writable devices from the alloc list should also be accompanied by a decrement to rw_devices. Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com Fixes: cf89af14 ("btrfs: dev-replace: fail mount if we don't have replace item with target device") CC: stable@vger.kernel.org # 5.10+ Tested-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com Reviewed-by:Anand Jain <anand.jain@oracle.com> Signed-off-by:
Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> Signed-off-by:
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Filipe Manana authored
When checking if we need to log the new name of a renamed inode, we are checking if the inode and its parent inode have been logged before, and if not we don't log the new name. The check however is buggy, as it directly compares the logged_trans field of the inodes versus the ID of the current transaction. The problem is that logged_trans is a transient field, only stored in memory and never persisted in the inode item, so if an inode was logged before, evicted and reloaded, its logged_trans field is set to a value of 0, meaning the check will return false and the new name of the renamed inode is not logged. If the old parent directory was previously fsynced and we deleted the logged directory entries corresponding to the old name, we end up with a log that when replayed will delete the renamed inode. The following example triggers the problem: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ echo -n "hello world" > /mnt/A/foo $ sync # Add some new file to A and fsync directory A. $ touch /mnt/A/bar $ xfs_io -c "fsync" /mnt/A # Now trigger inode eviction. We are only interested in triggering # eviction for the inode of directory A. $ echo 2 > /proc/sys/vm/drop_caches # Move foo from directory A to directory B. # This deletes the directory entries for foo in A from the log, and # does not add the new name for foo in directory B to the log, because # logged_trans of A is 0, which is less than the current transaction ID. $ mv /mnt/A/foo /mnt/B/foo # Now make an fsync to anything except A, B or any file inside them, # like for example create a file at the root directory and fsync this # new file. This syncs the log that contains all the changes done by # previous rename operation. $ touch /mnt/baz $ xfs_io -c "fsync" /mnt/baz <power fail> # Mount the filesystem and replay the log. $ mount /dev/sdc /mnt # Check the filesystem content. $ ls -1R /mnt /mnt/: A B baz /mnt/A: bar /mnt/B: $ # File foo is gone, it's neither in A/ nor in B/. Fix this by using the inode_logged() helper at btrfs_log_new_name(), which safely checks if an inode was logged before in the current transaction. A test case for fstests will follow soon. CC: stable@vger.kernel.org # 4.14+ Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
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Goldwyn Rodrigues authored
In compression write endio sequence, the range which the compressed_bio writes is marked as uptodate if the last bio of the compressed (sub)bios is completed successfully. There could be previous bio which may have failed which is recorded in cb->errors. Set the writeback range as uptodate only if cb->errors is zero, as opposed to checking only the last bio's status. Backporting notes: in all versions up to 4.4 the last argument is always replaced by "!cb->errors". CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by:
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- 22 Jul, 2021 4 commits
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Christoph Hellwig authored
Store the block device instead of the gendisk in the btrfs_ordered_extent structure instead of acquiring a reference to it later. Note: this is from series removing bdgrab/bdput, btrfs is one of the last users. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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Filipe Manana authored
At btrfs_qgroup_trace_extent_post() we call btrfs_find_all_roots() with a NULL value as the transaction handle argument, which makes that function take the commit_root_sem semaphore, which is necessary when we don't hold a transaction handle or any other mechanism to prevent a transaction commit from wiping out commit roots. However btrfs_qgroup_trace_extent_post() can be called in a context where we are holding a write lock on an extent buffer from a subvolume tree, namely from btrfs_truncate_inode_items(), called either during truncate or unlink operations. In this case we end up with a lock inversion problem because the commit_root_sem is a higher level lock, always supposed to be acquired before locking any extent buffer. Lockdep detects this lock inversion problem since we switched the extent buffer locks from custom locks to semaphores, and when running btrfs/158 from fstests, it reported the following trace: [ 9057.626435] ====================================================== [ 9057.627541] WARNING: possible circular locking dependency detected [ 9057.628334] 5.14.0-rc2-btrfs-next-93 #1 Not tainted [ 9057.628961] ------------------------------------------------------ [ 9057.629867] kworker/u16:4/30781 is trying to acquire lock: [ 9057.630824] ffff8e2590f58760 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 9057.632542] but task is already holding lock: [ 9057.633551] ffff8e25582d4b70 (&fs_info->commit_root_sem){++++}-{3:3}, at: iterate_extent_inodes+0x10b/0x280 [btrfs] [ 9057.635255] which lock already depends on the new lock. [ 9057.636292] the existing dependency chain (in reverse order) is: [ 9057.637240] -> #1 (&fs_info->commit_root_sem){++++}-{3:3}: [ 9057.638138] down_read+0x46/0x140 [ 9057.638648] btrfs_find_all_roots+0x41/0x80 [btrfs] [ 9057.639398] btrfs_qgroup_trace_extent_post+0x37/0x70 [btrfs] [ 9057.640283] btrfs_add_delayed_data_ref+0x418/0x490 [btrfs] [ 9057.641114] btrfs_free_extent+0x35/0xb0 [btrfs] [ 9057.641819] btrfs_truncate_inode_items+0x424/0xf70 [btrfs] [ 9057.642643] btrfs_evict_inode+0x454/0x4f0 [btrfs] [ 9057.643418] evict+0xcf/0x1d0 [ 9057.643895] do_unlinkat+0x1e9/0x300 [ 9057.644525] do_syscall_64+0x3b/0xc0 [ 9057.645110] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 9057.645835] -> #0 (btrfs-tree-00){++++}-{3:3}: [ 9057.646600] __lock_acquire+0x130e/0x2210 [ 9057.647248] lock_acquire+0xd7/0x310 [ 9057.647773] down_read_nested+0x4b/0x140 [ 9057.648350] __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 9057.649175] btrfs_read_lock_root_node+0x31/0x40 [btrfs] [ 9057.650010] btrfs_search_slot+0x537/0xc00 [btrfs] [ 9057.650849] scrub_print_warning_inode+0x89/0x370 [btrfs] [ 9057.651733] iterate_extent_inodes+0x1e3/0x280 [btrfs] [ 9057.652501] scrub_print_warning+0x15d/0x2f0 [btrfs] [ 9057.653264] scrub_handle_errored_block.isra.0+0x135f/0x1640 [btrfs] [ 9057.654295] scrub_bio_end_io_worker+0x101/0x2e0 [btrfs] [ 9057.655111] btrfs_work_helper+0xf8/0x400 [btrfs] [ 9057.655831] process_one_work+0x247/0x5a0 [ 9057.656425] worker_thread+0x55/0x3c0 [ 9057.656993] kthread+0x155/0x180 [ 9057.657494] ret_from_fork+0x22/0x30 [ 9057.658030] other info that might help us debug this: [ 9057.659064] Possible unsafe locking scenario: [ 9057.659824] CPU0 CPU1 [ 9057.660402] ---- ---- [ 9057.660988] lock(&fs_info->commit_root_sem); [ 9057.661581] lock(btrfs-tree-00); [ 9057.662348] lock(&fs_info->commit_root_sem); [ 9057.663254] lock(btrfs-tree-00); [ 9057.663690] *** DEADLOCK *** [ 9057.664437] 4 locks held by kworker/u16:4/30781: [ 9057.665023] #0: ffff8e25922a1148 ((wq_completion)btrfs-scrub){+.+.}-{0:0}, at: process_one_work+0x1c7/0x5a0 [ 9057.666260] #1: ffffabb3451ffe70 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x1c7/0x5a0 [ 9057.667639] #2: ffff8e25922da198 (&ret->mutex){+.+.}-{3:3}, at: scrub_handle_errored_block.isra.0+0x5d2/0x1640 [btrfs] [ 9057.669017] #3: ffff8e25582d4b70 (&fs_info->commit_root_sem){++++}-{3:3}, at: iterate_extent_inodes+0x10b/0x280 [btrfs] [ 9057.670408] stack backtrace: [ 9057.670976] CPU: 7 PID: 30781 Comm: kworker/u16:4 Not tainted 5.14.0-rc2-btrfs-next-93 #1 [ 9057.672030] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 9057.673492] Workqueue: btrfs-scrub btrfs_work_helper [btrfs] [ 9057.674258] Call Trace: [ 9057.674588] dump_stack_lvl+0x57/0x72 [ 9057.675083] check_noncircular+0xf3/0x110 [ 9057.675611] __lock_acquire+0x130e/0x2210 [ 9057.676132] lock_acquire+0xd7/0x310 [ 9057.676605] ? __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 9057.677313] ? lock_is_held_type+0xe8/0x140 [ 9057.677849] down_read_nested+0x4b/0x140 [ 9057.678349] ? __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 9057.679068] __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 9057.679760] btrfs_read_lock_root_node+0x31/0x40 [btrfs] [ 9057.680458] btrfs_search_slot+0x537/0xc00 [btrfs] [ 9057.681083] ? _raw_spin_unlock+0x29/0x40 [ 9057.681594] ? btrfs_find_all_roots_safe+0x11f/0x140 [btrfs] [ 9057.682336] scrub_print_warning_inode+0x89/0x370 [btrfs] [ 9057.683058] ? btrfs_find_all_roots_safe+0x11f/0x140 [btrfs] [ 9057.683834] ? scrub_write_block_to_dev_replace+0xb0/0xb0 [btrfs] [ 9057.684632] iterate_extent_inodes+0x1e3/0x280 [btrfs] [ 9057.685316] scrub_print_warning+0x15d/0x2f0 [btrfs] [ 9057.685977] ? ___ratelimit+0xa4/0x110 [ 9057.686460] scrub_handle_errored_block.isra.0+0x135f/0x1640 [btrfs] [ 9057.687316] scrub_bio_end_io_worker+0x101/0x2e0 [btrfs] [ 9057.688021] btrfs_work_helper+0xf8/0x400 [btrfs] [ 9057.688649] ? lock_is_held_type+0xe8/0x140 [ 9057.689180] process_one_work+0x247/0x5a0 [ 9057.689696] worker_thread+0x55/0x3c0 [ 9057.690175] ? process_one_work+0x5a0/0x5a0 [ 9057.690731] kthread+0x155/0x180 [ 9057.691158] ? set_kthread_struct+0x40/0x40 [ 9057.691697] ret_from_fork+0x22/0x30 Fix this by making btrfs_find_all_roots() never attempt to lock the commit_root_sem when it is called from btrfs_qgroup_trace_extent_post(). We can't just pass a non-NULL transaction handle to btrfs_find_all_roots() from btrfs_qgroup_trace_extent_post(), because that would make backref lookup not use commit roots and acquire read locks on extent buffers, and therefore could deadlock when btrfs_qgroup_trace_extent_post() is called from the btrfs_truncate_inode_items() code path which has acquired a write lock on an extent buffer of the subvolume btree. CC: stable@vger.kernel.org # 4.19+ Reviewed-by: -
Anand Jain authored
A fstrim on a degraded raid1 can trigger the following null pointer dereference: BTRFS info (device loop0): allowing degraded mounts BTRFS info (device loop0): disk space caching is enabled BTRFS info (device loop0): has skinny extents BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS warning (device loop0): devid 2 uuid 97ac16f7-e14d-4db1-95bc-3d489b424adb is missing BTRFS info (device loop0): enabling ssd optimizations BUG: kernel NULL pointer dereference, address: 0000000000000620 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 4574 Comm: fstrim Not tainted 5.13.0-rc7+ #31 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:btrfs_trim_fs+0x199/0x4a0 [btrfs] RSP: 0018:ffff959541797d28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff946f84eca508 RCX: a7a67937adff8608 RDX: ffff946e8122d000 RSI: 0000000000000000 RDI: ffffffffc02fdbf0 RBP: ffff946ea4615000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff946e8122d960 R12: 0000000000000000 R13: ffff959541797db8 R14: ffff946e8122d000 R15: ffff959541797db8 FS: 00007f55917a5080(0000) GS:ffff946f9bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000620 CR3: 000000002d2c8001 CR4: 00000000000706f0 Call Trace: btrfs_ioctl_fitrim+0x167/0x260 [btrfs] btrfs_ioctl+0x1c00/0x2fe0 [btrfs] ? selinux_file_ioctl+0x140/0x240 ? syscall_trace_enter.constprop.0+0x188/0x240 ? __x64_sys_ioctl+0x83/0xb0 __x64_sys_ioctl+0x83/0xb0 Reproducer: $ mkfs.btrfs -fq -d raid1 -m raid1 /dev/loop0 /dev/loop1 $ mount /dev/loop0 /btrfs $ umount /btrfs $ btrfs dev scan --forget $ mount -o degraded /dev/loop0 /btrfs $ fstrim /btrfs The reason is we call btrfs_trim_free_extents() for the missing device, which uses device->bdev (NULL for missing device) to find if the device supports discard. Fix is to check if the device is missing before calling btrfs_trim_free_extents(). CC: stable@vger.kernel.org # 5.4+ Reviewed-by:
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Filipe Manana authored
If we have an inode that does not have the full sync flag set, was changed in the current transaction, then it is logged while logging some other inode (like its parent directory for example), its i_size is increased by a truncate operation, the log is synced through an fsync of some other inode and then finally we explicitly call fsync on our inode, the new i_size is not persisted. The following example shows how to trigger it, with comments explaining how and why the issue happens: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ touch /mnt/foo $ xfs_io -f -c "pwrite -S 0xab 0 1M" /mnt/bar $ sync # Fsync bar, this will be a noop since the file has not yet been # modified in the current transaction. The goal here is to clear # BTRFS_INODE_NEEDS_FULL_SYNC from the inode's runtime flags. $ xfs_io -c "fsync" /mnt/bar # Now rename both files, without changing their parent directory. $ mv /mnt/bar /mnt/bar2 $ mv /mnt/foo /mnt/foo2 # Increase the size of bar2 with a truncate operation. $ xfs_io -c "truncate 2M" /mnt/bar2 # Now fsync foo2, this results in logging its parent inode (the root # directory), and logging the parent results in logging the inode of # file bar2 (its inode item and the new name). The inode of file bar2 # is logged with an i_size of 0 bytes since it's logged in # LOG_INODE_EXISTS mode, meaning we are only logging its names (and # xattrs if it had any) and the i_size of the inode will not be changed # when the log is replayed. $ xfs_io -c "fsync" /mnt/foo2 # Now explicitly fsync bar2. This resulted in doing nothing, not # logging the inode with the new i_size of 2M and the hole from file # offset 1M to 2M. Because the inode did not have the flag # BTRFS_INODE_NEEDS_FULL_SYNC set, when it was logged through the # fsync of file foo2, its last_log_commit field was updated, # resulting in this explicit of file bar2 not doing anything. $ xfs_io -c "fsync" /mnt/bar2 # File bar2 content and size before a power failure. $ od -A d -t x1 /mnt/bar2 0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 1048576 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 2097152 <power failure> # Mount the filesystem to replay the log. $ mount /dev/sdc /mnt # Read the file again, should have the same content and size as before # the power failure happened, but it doesn't, i_size is still at 1M. $ od -A d -t x1 /mnt/bar2 0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 1048576 This started to happen after commit 209ecbb8 ("btrfs: remove stale comment and logic from btrfs_inode_in_log()"), since btrfs_inode_in_log() no longer checks if the inode's list of modified extents is not empty. However, checking that list is not the right way to address this case and the check was added long time ago in commit 125c4cf9 ("Btrfs: set inode's logged_trans/last_log_commit after ranged fsync") for a different purpose, to address consecutive ranged fsyncs. The reason that checking for the list emptiness makes this test pass is because during an expanding truncate we create an extent map to represent a hole from the old i_size to the new i_size, and add that extent map to the list of modified extents in the inode. However if we are low on available memory and we can not allocate a new extent map, then we don't treat it as an error and just set the full sync flag on the inode, so that the next fsync does not rely on the list of modified extents - so checking for the emptiness of the list to decide if the inode needs to be logged is not reliable, and results in not logging the inode if it was not possible to allocate the extent map for the hole. Fix this by ensuring that if we are only logging that an inode exists (inode item, names/references and xattrs), we don't update the inode's last_log_commit even if it does not have the full sync runtime flag set. A test case for fstests follows soon. CC: stable@vger.kernel.org # 5.13+ Signed-off-by:
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- 07 Jul, 2021 7 commits
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Filipe Manana authored
When syncing the log, if we fail to allocate the root node for the log root tree: 1) We are unlocking fs_info->tree_log_mutex, but at this point we have not yet locked this mutex; 2) We have locked fs_info->tree_root->log_mutex, but we end up not unlocking it; So fix this by unlocking fs_info->tree_root->log_mutex instead of fs_info->tree_log_mutex. Fixes: e75f9fd1 ("btrfs: zoned: move log tree node allocation out of log_root_tree->log_mutex") CC: stable@vger.kernel.org # 5.13+ Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
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Johannes Thumshirn authored
If we can't acquire the reclaim_bgs_lock on block group reclaim, we block until it is free. This can potentially stall for a long time. While reclaim of block groups is necessary for a good user experience on a zoned file system, there still is no need to block as it is best effort only, just like when we're deleting unused block groups. CC: stable@vger.kernel.org # 5.13 Signed-off-by:
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Naohiro Aota authored
Damien reported a test failure with btrfs/209. The test itself ran fine, but the fsck ran afterwards reported a corrupted filesystem. The filesystem corruption happens because we're splitting an extent and then writing the extent twice. We have to split the extent though, because we're creating too large extents for a REQ_OP_ZONE_APPEND operation. When dumping the extent tree, we can see two EXTENT_ITEMs at the same start address but different lengths. $ btrfs inspect dump-tree /dev/nullb1 -t extent ... item 19 key (269484032 EXTENT_ITEM 126976) itemoff 15470 itemsize 53 refs 1 gen 7 flags DATA extent data backref root FS_TREE objectid 257 offset 786432 count 1 item 20 key (269484032 EXTENT_ITEM 262144) itemoff 15417 itemsize 53 refs 1 gen 7 flags DATA extent data backref root FS_TREE objectid 257 offset 786432 count 1 The duplicated EXTENT_ITEMs originally come from wrongly split extent_map in extract_ordered_extent(). Since extract_ordered_extent() uses create_io_em() to split an existing extent_map, we will have split->orig_start != split->start. Then, it will be logged with non-zero "extent data offset". Finally, the logged entries are replayed into a duplicated EXTENT_ITEM. Introduce and use proper splitting function for extent_map. The function is intended to be simple and specific usage for extract_ordered_extent() e.g. not supporting compression case (we do not allow splitting compressed extent_map anyway). There was a question raised by Qu, in summary why we want to split the extent map (and not the bio): The problem is not the limit on the zone end, which as you mention is the same as the block group end. The problem is that data write use zone append (ZA) operations. ZA BIOs cannot be split so a large extent may need to be processed with multiple ZA BIOs, While that is also true for regular writes, the major difference is that ZA are "nameless" write operation giving back the written sectors on completion. And ZA operations may be reordered by the block layer (not intentionally though). Combine both of these characteristics and you can see that the data for a large extent may end up being shuffled when written resulting in data corruption and the impossibility to map the extent to some start sector. To avoid this problem, zoned btrfs uses the principle "one data extent == one ZA BIO". So large extents need to be split. This is unfortunate, but we can revisit this later and optimize, e.g. merge back together the fragments of an extent once written if they actually were written sequentially in the zone. Reported-by:Damien Le Moal <damien.lemoal@wdc.com> Fixes: d22002fd ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ CC: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by:
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Filipe Manana authored
Commit eafa4fd0 ("btrfs: fix exhaustion of the system chunk array due to concurrent allocations") fixed a problem that resulted in exhausting the system chunk array in the superblock when there are many tasks allocating chunks in parallel. Basically too many tasks enter the first phase of chunk allocation without previous tasks having finished their second phase of allocation, resulting in too many system chunks being allocated. That was originally observed when running the fallocate tests of stress-ng on a PowerPC machine, using a node size of 64K. However that commit also introduced a deadlock where a task in phase 1 of the chunk allocation waited for another task that had allocated a system chunk to finish its phase 2, but that other task was waiting on an extent buffer lock held by the first task, therefore resulting in both tasks not making any progress. That change was later reverted by a patch with the subject "btrfs: fix deadlock with concurrent chunk allocations involving system chunks", since there is no simple and short solution to address it and the deadlock is relatively easy to trigger on zoned filesystems, while the system chunk array exhaustion is not so common. This change reworks the chunk allocation to avoid the system chunk array exhaustion. It accomplishes that by making the first phase of chunk allocation do the updates of the device items in the chunk btree and the insertion of the new chunk item in the chunk btree. This is done while under the protection of the chunk mutex (fs_info->chunk_mutex), in the same critical section that checks for available system space, allocates a new system chunk if needed and reserves system chunk space. This way we do not have chunk space reserved until the second phase completes. The same logic is applied to chunk removal as well, since it keeps reserved system space long after it is done updating the chunk btree. For direct allocation of system chunks, the previous behaviour remains, because otherwise we would deadlock on extent buffers of the chunk btree. Changes to the chunk btree are by large done by chunk allocation and chunk removal, which first reserve chunk system space and then later do changes to the chunk btree. The other remaining cases are uncommon and correspond to adding a device, removing a device and resizing a device. All these other cases do not pre-reserve system space, they modify the chunk btree right away, so they don't hold reserved space for a long period like chunk allocation and chunk removal do. The diff of this change is huge, but more than half of it is just addition of comments describing both how things work regarding chunk allocation and removal, including both the new behavior and the parts of the old behavior that did not change. CC: stable@vger.kernel.org # 5.12+ Tested-by:
Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Tested-by:
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Filipe Manana authored
When a task attempting to allocate a new chunk verifies that there is not currently enough free space in the system space_info and there is another task that allocated a new system chunk but it did not finish yet the creation of the respective block group, it waits for that other task to finish creating the block group. This is to avoid exhaustion of the system chunk array in the superblock, which is limited, when we have a thundering herd of tasks allocating new chunks. This problem was described and fixed by commit eafa4fd0 ("btrfs: fix exhaustion of the system chunk array due to concurrent allocations"). However there are two very similar scenarios where this can lead to a deadlock: 1) Task B allocated a new system chunk and task A is waiting on task B to finish creation of the respective system block group. However before task B ends its transaction handle and finishes the creation of the system block group, it attempts to allocate another chunk (like a data chunk for an fallocate operation for a very large range). Task B will be unable to progress and allocate the new chunk, because task A set space_info->chunk_alloc to 1 and therefore it loops at btrfs_chunk_alloc() waiting for task A to finish its chunk allocation and set space_info->chunk_alloc to 0, but task A is waiting on task B to finish creation of the new system block group, therefore resulting in a deadlock; 2) Task B allocated a new system chunk and task A is waiting on task B to finish creation of the respective system block group. By the time that task B enter the final phase of block group allocation, which happens at btrfs_create_pending_block_groups(), when it modifies the extent tree, the device tree or the chunk tree to insert the items for some new block group, it needs to allocate a new chunk, so it ends up at btrfs_chunk_alloc() and keeps looping there because task A has set space_info->chunk_alloc to 1, but task A is waiting for task B to finish creation of the new system block group and release the reserved system space, therefore resulting in a deadlock. In short, the problem is if a task B needs to allocate a new chunk after it previously allocated a new system chunk and if another task A is currently waiting for task B to complete the allocation of the new system chunk. Unfortunately this deadlock scenario introduced by the previous fix for the system chunk array exhaustion problem does not have a simple and short fix, and requires a big change to rework the chunk allocation code so that chunk btree updates are all made in the first phase of chunk allocation. And since this deadlock regression is being frequently hit on zoned filesystems and the system chunk array exhaustion problem is triggered in more extreme cases (originally observed on PowerPC with a node size of 64K when running the fallocate tests from stress-ng), revert the changes from that commit. The next patch in the series, with a subject of "btrfs: rework chunk allocation to avoid exhaustion of the system chunk array" does the necessary changes to fix the system chunk array exhaustion problem. Reported-by:
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Johannes Thumshirn authored
When we're automatically reclaiming a zone, because its zone_unusable value is above the reclaim threshold, we're only logging how much percent of the zone's capacity are used, but not how much of the capacity is unusable. Also print the percentage of the unusable space in the block group before we're reclaiming it. Example: BTRFS info (device sdg): reclaiming chunk 230686720 with 13% used 86% unusable CC: stable@vger.kernel.org # 5.13 Signed-off-by:
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David Sterba authored
The types in calculation of the used percentage in the reclaiming messages are both u64, though bg->length is either 1GiB (non-zoned) or the zone size in the zoned mode. The upper limit on zone size is 8GiB so this could theoretically overflow in the future, right now the values fit. Fixes: 18bb8bbf ("btrfs: zoned: automatically reclaim zones") CC: stable@vger.kernel.org # 5.13 Reviewed-by:
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- 22 Jun, 2021 18 commits
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Nikolay Borisov authored
This got added 14 years ago in 324ae4df ("Btrfs: Add block group pinned accounting back") but it was not ever used. Subsequently its usage got gradually removed in 8790d502 ("Btrfs: Add support for mirroring across drives") and 11833d66 ("Btrfs: improve async block group caching"). Let's remove it for good! Reviewed-by:
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Josef Bacik authored
We used this in may_commit_transaction() in order to determine if we needed to commit the transaction. However we no longer have that logic and thus have no use of this counter anymore, so delete it. Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Reviewed-by:
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Josef Bacik authored
This was a trick implemented to handle the case where we had a giant reservation in front of a bunch of little reservations in the ticket queue. If the giant reservation was too large for the transaction commit to make a difference we'd ENOSPC everybody out instead of committing the transaction. This logic was put in to force us to go back and re-try the transaction commit logic to see if we could make progress. Instead now we know we've committed the transaction, so any space that would have been recovered is now available, and would be caught by the btrfs_try_granting_tickets() in this loop, so we no longer need this code and can simply delete it. Reviewed-by:
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Josef Bacik authored
Since we unconditionally commit the transaction now we no longer need to run the delayed refs to make sure our total_bytes_pinned value is uptodate, we can simply commit the transaction. Remove this stage from the data flushing list. Reviewed-by:
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Josef Bacik authored
may_commit_transaction was introduced before the ticketing infrastructure existed. There was a problem where we'd legitimately be out of space, but every reservation would trigger a transaction commit and then fail. Thus if you had 1000 things trying to make a reservation, they'd all do the flushing loop and thus commit the transaction 1000 times before they'd get their ENOSPC. This helper was introduced to short circuit this, if there wasn't space that could be reclaimed by committing the transaction then simply ENOSPC out. This made true ENOSPC tests much faster as we didn't waste a bunch of time. However many of our bugs over the years have been from cases where we didn't account for some space that would be reclaimed by committing a transaction. The delayed refs rsv space, delayed rsv, many pinned bytes miscalculations, etc. And in the meantime the original problem has been solved with ticketing. We no longer will commit the transaction 1000 times. Instead we'll get 1000 waiters, we will go through the flushing mechanisms, and if there's no progress after 2 loops we ENOSPC everybody out. The ticketing infrastructure gives us a deterministic way to see if we're making progress or not, thus we avoid a lot of extra work. So simplify this step by simply unconditionally committing the transaction. This removes what is arguably our most common source of early ENOSPC bugs and will allow us to drastically simplify many of the things we track because we simply won't need them with this stuff gone. Reviewed-by:
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Filipe Manana authored
When doing a send we don't expect the task to ever start a transaction after the initial check that verifies if commit roots match the regular roots. This is because after that we set current->journal_info with a stub (special value) that signals we are in send context, so that we take a read lock on an extent buffer when reading it from disk and verifying it is valid (its generation matches the generation stored in the parent). This stub was introduced in 2014 by commit a26e8c9f ("Btrfs: don't clear uptodate if the eb is under IO") in order to fix a concurrency issue between send and balance. However there is one particular exception where we end up needing to start a transaction and when this happens it results in a crash with a stack trace like the following: [60015.902283] kernel: WARNING: CPU: 3 PID: 58159 at arch/x86/include/asm/kfence.h:44 kfence_protect_page+0x21/0x80 [60015.902292] kernel: Modules linked in: uinput rfcomm snd_seq_dummy (...) [60015.902384] kernel: CPU: 3 PID: 58159 Comm: btrfs Not tainted 5.12.9-300.fc34.x86_64 #1 [60015.902387] kernel: Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./F2A88XN-WIFI, BIOS F6 12/24/2015 [60015.902389] kernel: RIP: 0010:kfence_protect_page+0x21/0x80 [60015.902393] kernel: Code: ff 0f 1f 84 00 00 00 00 00 55 48 89 fd (...) [60015.902396] kernel: RSP: 0018:ffff9fb583453220 EFLAGS: 00010246 [60015.902399] kernel: RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9fb583453224 [60015.902401] kernel: RDX: ffff9fb583453224 RSI: 0000000000000000 RDI: 0000000000000000 [60015.902402] kernel: RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [60015.902404] kernel: R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 [60015.902406] kernel: R13: ffff9fb583453348 R14: 0000000000000000 R15: 0000000000000001 [60015.902408] kernel: FS: 00007f158e62d8c0(0000) GS:ffff93bd37580000(0000) knlGS:0000000000000000 [60015.902410] kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [60015.902412] kernel: CR2: 0000000000000039 CR3: 00000001256d2000 CR4: 00000000000506e0 [60015.902414] kernel: Call Trace: [60015.902419] kernel: kfence_unprotect+0x13/0x30 [60015.902423] kernel: page_fault_oops+0x89/0x270 [60015.902427] kernel: ? search_module_extables+0xf/0x40 [60015.902431] kernel: ? search_bpf_extables+0x57/0x70 [60015.902435] kernel: kernelmode_fixup_or_oops+0xd6/0xf0 [60015.902437] kernel: __bad_area_nosemaphore+0x142/0x180 [60015.902440] kernel: exc_page_fault+0x67/0x150 [60015.902445] kernel: asm_exc_page_fault+0x1e/0x30 [60015.902450] kernel: RIP: 0010:start_transaction+0x71/0x580 [60015.902454] kernel: Code: d3 0f 84 92 00 00 00 80 e7 06 0f 85 63 (...) [60015.902456] kernel: RSP: 0018:ffff9fb5834533f8 EFLAGS: 00010246 [60015.902458] kernel: RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000 [60015.902460] kernel: RDX: 0000000000000801 RSI: 0000000000000000 RDI: 0000000000000039 [60015.902462] kernel: RBP: ffff93bc0a7eb800 R08: 0000000000000001 R09: 0000000000000000 [60015.902463] kernel: R10: 0000000000098a00 R11: 0000000000000001 R12: 0000000000000001 [60015.902464] kernel: R13: 0000000000000000 R14: ffff93bc0c92b000 R15: ffff93bc0c92b000 [60015.902468] kernel: btrfs_commit_inode_delayed_inode+0x5d/0x120 [60015.902473] kernel: btrfs_evict_inode+0x2c5/0x3f0 [60015.902476] kernel: evict+0xd1/0x180 [60015.902480] kernel: inode_lru_isolate+0xe7/0x180 [60015.902483] kernel: __list_lru_walk_one+0x77/0x150 [60015.902487] kernel: ? iput+0x1a0/0x1a0 [60015.902489] kernel: ? iput+0x1a0/0x1a0 [60015.902491] kernel: list_lru_walk_one+0x47/0x70 [60015.902495] kernel: prune_icache_sb+0x39/0x50 [60015.902497] kernel: super_cache_scan+0x161/0x1f0 [60015.902501] kernel: do_shrink_slab+0x142/0x240 [60015.902505] kernel: shrink_slab+0x164/0x280 [60015.902509] kernel: shrink_node+0x2c8/0x6e0 [60015.902512] kernel: do_try_to_free_pages+0xcb/0x4b0 [60015.902514] kernel: try_to_free_pages+0xda/0x190 [60015.902516] kernel: __alloc_pages_slowpath.constprop.0+0x373/0xcc0 [60015.902521] kernel: ? __memcg_kmem_charge_page+0xc2/0x1e0 [60015.902525] kernel: __alloc_pages_nodemask+0x30a/0x340 [60015.902528] kernel: pipe_write+0x30b/0x5c0 [60015.902531] kernel: ? set_next_entity+0xad/0x1e0 [60015.902534] kernel: ? switch_mm_irqs_off+0x58/0x440 [60015.902538] kernel: __kernel_write+0x13a/0x2b0 [60015.902541] kernel: kernel_write+0x73/0x150 [60015.902543] kernel: send_cmd+0x7b/0xd0 [60015.902545] kernel: send_extent_data+0x5a3/0x6b0 [60015.902549] kernel: process_extent+0x19b/0xed0 [60015.902551] kernel: btrfs_ioctl_send+0x1434/0x17e0 [60015.902554] kernel: ? _btrfs_ioctl_send+0xe1/0x100 [60015.902557] kernel: _btrfs_ioctl_send+0xbf/0x100 [60015.902559] kernel: ? enqueue_entity+0x18c/0x7b0 [60015.902562] kernel: btrfs_ioctl+0x185f/0x2f80 [60015.902564] kernel: ? psi_task_change+0x84/0xc0 [60015.902569] kernel: ? _flat_send_IPI_mask+0x21/0x40 [60015.902572] kernel: ? check_preempt_curr+0x2f/0x70 [60015.902576] kernel: ? selinux_file_ioctl+0x137/0x1e0 [60015.902579] kernel: ? expand_files+0x1cb/0x1d0 [60015.902582] kernel: ? __x64_sys_ioctl+0x82/0xb0 [60015.902585] kernel: __x64_sys_ioctl+0x82/0xb0 [60015.902588] kernel: do_syscall_64+0x33/0x40 [60015.902591] kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae [60015.902595] kernel: RIP: 0033:0x7f158e38f0ab [60015.902599] kernel: Code: ff ff ff 85 c0 79 9b (...) [60015.902602] kernel: RSP: 002b:00007ffcb2519bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [60015.902605] kernel: RAX: ffffffffffffffda RBX: 00007ffcb251ae00 RCX: 00007f158e38f0ab [60015.902607] kernel: RDX: 00007ffcb2519cf0 RSI: 0000000040489426 RDI: 0000000000000004 [60015.902608] kernel: RBP: 0000000000000004 R08: 00007f158e297640 R09: 00007f158e297640 [60015.902610] kernel: R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 [60015.902612] kernel: R13: 0000000000000002 R14: 00007ffcb251aee0 R15: 0000558c1a83e2a0 [60015.902615] kernel: ---[ end trace 7bbc33e23bb887ae ]--- This happens because when writing to the pipe, by calling kernel_write(), we end up doing page allocations using GFP_HIGHUSER | __GFP_ACCOUNT as the gfp flags, which allow reclaim to happen if there is memory pressure. This allocation happens at fs/pipe.c:pipe_write(). If the reclaim is triggered, inode eviction can be triggered and that in turn can result in starting a transaction if the inode has a link count of 0. The transaction start happens early on during eviction, when we call btrfs_commit_inode_delayed_inode() at btrfs_evict_inode(). This happens if there is currently an open file descriptor for an inode with a link count of 0 and the reclaim task gets a reference on the inode before that descriptor is closed, in which case the reclaim task ends up doing the final iput that triggers the inode eviction. When we have assertions enabled (CONFIG_BTRFS_ASSERT=y), this triggers the following assertion at transaction.c:start_transaction(): /* Send isn't supposed to start transactions. */ ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB); And when assertions are not enabled, it triggers a crash since after that assertion we cast current->journal_info into a transaction handle pointer and then dereference it: if (current->journal_info) { WARN_ON(type & TRANS_EXTWRITERS); h = current->journal_info; refcount_inc(&h->use_count); (...) Which obviously results in a crash due to an invalid memory access. The same type of issue can happen during other memory allocations we do directly in the send code with kmalloc (and friends) as they use GFP_KERNEL and therefore may trigger reclaim too, which started to happen since 2016 after commit e780b0d1 ("btrfs: send: use GFP_KERNEL everywhere"). The issue could be solved by setting up a NOFS context for the entire send operation so that reclaim could not be triggered when allocating memory or pages through kernel_write(). However that is not very friendly and we can in fact get rid of the send stub because: 1) The stub was introduced way back in 2014 by commit a26e8c9f ("Btrfs: don't clear uptodate if the eb is under IO") to solve an issue exclusive to when send and balance are running in parallel, however there were other problems between balance and send and we do not allow anymore to have balance and send run concurrently since commit 9e967495 ("Btrfs: prevent send failures and crashes due to concurrent relocation"). More generically the issues are between send and relocation, and that last commit eliminated only the possibility of having send and balance run concurrently, but shrinking a device also can trigger relocation, and on zoned filesystems we have relocation of partially used block groups triggered automatically as well. The previous patch that has a subject of: "btrfs: ensure relocation never runs while we have send operations running" Addresses all the remaining cases that can trigger relocation. 2) We can actually allow starting and even committing transactions while in a send context if needed because send is not holding any locks that would block the start or the commit of a transaction. So get rid of all the logic added by commit a26e8c9f ("Btrfs: don't clear uptodate if the eb is under IO"). We can now always call clear_extent_buffer_uptodate() at verify_parent_transid() since send is the only case that uses commit roots without having a transaction open or without holding the commit_root_sem. Reported-by:
Chris Murphy <lists@colorremedies.com> Link: https://lore.kernel.org/linux-btrfs/CAJCQCtRQ57=qXo3kygwpwEBOU_CA_eKvdmjP52sU=eFvuVOEGw@mail.gmail.com/Signed-off-by:
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Filipe Manana authored
Relocation and send do not play well together because while send is running a block group can be relocated, a transaction committed and the respective disk extents get re-allocated and written to or discarded while send is about to do something with the extents. This was explained in commit 9e967495 ("Btrfs: prevent send failures and crashes due to concurrent relocation"), which prevented balance and send from running in parallel but it did not address one remaining case where chunk relocation can happen: shrinking a device (and device deletion which shrinks a device's size to 0 before deleting the device). We also have now one more case where relocation is triggered: on zoned filesystems partially used block groups get relocated by a background thread, introduced in commit 18bb8bbf ("btrfs: zoned: automatically reclaim zones"). So make sure that instead of preventing balance from running when there are ongoing send operations, we prevent relocation from happening. This uses the infrastructure recently added by a patch that has the subject: "btrfs: add cancellable chunk relocation support". Also it adds a spinlock used exclusively for the exclusivity between send and relocation, as before fs_info->balance_mutex was used, which would make an attempt to run send to block waiting for balance to finish, which can take a lot of time on large filesystems. Signed-off-by:
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David Sterba authored
Subjectively, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA is quite long and calling it CHECK_INTEGRITY_DATA still keeps the meaning and matches the mount option name. Reviewed-by:
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David Sterba authored
Switch defines of BTRFS_MOUNT_* to an enum (the symbolic names are recorded in the debugging information for convenience). There are two more things done but separating them would not make much sense as it's touching the same lines: - Renumber shifts 18..31 to 17..30 to get rid of the hole in the sequence. - Use 1UL as the value that gets shifted because we're approaching the 32bit limit and due to integer promotions the value of (1 << 31) becomes 0xffffffff80000000 when cast to unsigned long (eg. the option manipulating helpers). This is not causing any problems yet as the operations are in-memory and masking the 31st bit works, we don't have more than 31 bits so the ill effects of not masking higher bits don't happen. But once we have more, the problems will emerge. Reviewed-by:
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David Sterba authored
Based on user feedback and actual problems with compression property, there's no support to unset any compression options, or to force no compression flag. Note: This has changed recently in e2fsprogs 1.46.2, 'chattr +m' (setting NOCOMPRESS). In btrfs properties, the empty value should really mean reset to defaults, for all properties in general. Right now there's only the compression one, so this change should not cause too many problems. Old behaviour: $ lsattr file ---------------------- file # the NOCOMPRESS bit is set $ btrfs prop set file compression '' $ lsattr file ---------------------m file This is equivalent to 'btrfs prop set file compression no' in current btrfs-progs as the 'no' or 'none' values are translated to an empty string. This is where the new behaviour is different: empty string drops the compression flag (-c) and nocompress (-m): $ lsattr file ---------------------- file # No change $ btrfs prop set file compression '' $ lsattr file ---------------------- file $ btrfs prop set file compression lzo $ lsattr file --------c------------- file $ btrfs prop get file compression compression=lzo $ btrfs prop set file compression '' # Reset to the initial state $ lsattr file ---------------------- file # Set NOCOMPRESS bit $ btrfs prop set file compression no $ lsattr file ---------------------m file This obviously brings problems with backward compatibility, so this patch should not be backported without making sure the updated btrfs-progs are also used and that scripts have been updated to use the new semantics. Summary: - old kernel: no, none, "" - set NOCOMPRESS bit - new kernel: no, none - set NOCOMPRESS bit "" - drop all compression flags, ie. COMPRESS and NOCOMPRESS Signed-off-by: -
David Sterba authored
The early check if we should attempt compression does not take into account the number of input pages. It can happen that there's only one page, eg. a tail page after some ranges of the BTRFS_MAX_UNCOMPRESSED have been processed, or an isolated page that won't be converted to an inline extent. The single page would be compressed but a later check would drop it again because the result size must be at least one block shorter than the input. That can never work with just one page. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: -
Naohiro Aota authored
qgroup_account_snapshot() is trying to unlock the not taken tree_log_mutex in a error path. Since ret != 0 in this case, we can just return from here. Fixes: 2a4d84c1 ("btrfs: move delayed ref flushing for qgroup into qgroup helper") CC: stable@vger.kernel.org # 5.12+ Reviewed-by:
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David Sterba authored
The device stats can be read by ioctl, wrapped by command 'btrfs device stats'. Provide another source where to read the information in /sys/fs/btrfs/FSID/devinfo/DEVID/error_stats . The format is a list of 'key value' pairs one per line, which is common in other stat files. The names are the same as used in other device stat outputs. The stats are all in one file as it's the snapshot of all available stats. The 'one value per file' format is not very suitable here. The stats should be valid right after the stats item is read from disk, shortly after initializing the device. In case the stats are not yet valid, print just 'invalid' as the file contents. Reviewed-by:
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David Sterba authored
Fix typos that have snuck in since the last round. Found by codespell. Signed-off-by: -
Qu Wenruo authored
Since commit 8140dc30 ("btrfs: btrfs_decompress_bio() could accept compressed_bio instead"), btrfs_decompress_bio() accepts "struct compressed_bio" other than open-coded parameter list. Thus the comments for the parameter list is no longer needed. Reviewed-by:
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Baokun Li authored
Use list_move_tail() instead of list_del() + list_add_tail() as it's doing the same thing and allows further cleanups. Open code name_cache_used() as there is only one user. Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Baokun Li <libaokun1@huawei.com> Reviewed-by:
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Christophe Leroy authored
With a config having PAGE_SIZE set to 256K, BTRFS build fails with the following message include/linux/compiler_types.h:326:38: error: call to '__compiletime_assert_791' declared with attribute error: BUILD_BUG_ON failed: (BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0 BTRFS_MAX_COMPRESSED being 128K, BTRFS cannot support platforms with 256K pages at the time being. There are two platforms that can select 256K pages: - hexagon - powerpc Disable BTRFS when 256K page size is selected. Supporting this would require changes to the subpage mode that's currently being developed. Given that 256K is many times larger than page sizes commonly used and for what the algorithms and structures have been tuned, it's out of scope and disabling build is a reasonable option. Reported-by:
kernel test robot <lkp@intel.com> Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> [ update changelog ] Signed-off-by:
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Filipe Manana authored
During an incremental send operation, when processing the new references for the current inode, we might send an unlink operation for another inode that has a conflicting path and has more than one hard link. However this path was computed and cached before we processed previous new references for the current inode. We may have orphanized a directory of that path while processing a previous new reference, in which case the path will be invalid and cause the receiver process to fail. The following reproducer triggers the problem and explains how/why it happens in its comments: $ cat test-send-unlink.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT # Create our test files and directory. Inode 259 (file3) has two hard # links. touch $MNT/file1 touch $MNT/file2 touch $MNT/file3 mkdir $MNT/A ln $MNT/file3 $MNT/A/hard_link # Filesystem looks like: # # . (ino 256) # |----- file1 (ino 257) # |----- file2 (ino 258) # |----- file3 (ino 259) # |----- A/ (ino 260) # |---- hard_link (ino 259) # # Now create the base snapshot, which is going to be the parent snapshot # for a later incremental send. btrfs subvolume snapshot -r $MNT $MNT/snap1 btrfs send -f /tmp/snap1.send $MNT/snap1 # Move inode 257 into directory inode 260. This results in computing the # path for inode 260 as "/A" and caching it. mv $MNT/file1 $MNT/A/file1 # Move inode 258 (file2) into directory inode 260, with a name of # "hard_link", moving first inode 259 away since it currently has that # location and name. mv $MNT/A/hard_link $MNT/tmp mv $MNT/file2 $MNT/A/hard_link # Now rename inode 260 to something else (B for example) and then create # a hard link for inode 258 that has the old name and location of inode # 260 ("/A"). mv $MNT/A $MNT/B ln $MNT/B/hard_link $MNT/A # Filesystem now looks like: # # . (ino 256) # |----- tmp (ino 259) # |----- file3 (ino 259) # |----- B/ (ino 260) # | |---- file1 (ino 257) # | |---- hard_link (ino 258) # | # |----- A (ino 258) # Create another snapshot of our subvolume and use it for an incremental # send. btrfs subvolume snapshot -r $MNT $MNT/snap2 btrfs send -f /tmp/snap2.send -p $MNT/snap1 $MNT/snap2 # Now unmount the filesystem, create a new one, mount it and try to # apply both send streams to recreate both snapshots. umount $DEV mkfs.btrfs -f $DEV >/dev/null mount $DEV $MNT # First add the first snapshot to the new filesystem by applying the # first send stream. btrfs receive -f /tmp/snap1.send $MNT # The incremental receive operation below used to fail with the # following error: # # ERROR: unlink A/hard_link failed: No such file or directory # # This is because when send is processing inode 257, it generates the # path for inode 260 as "/A", since that inode is its parent in the send # snapshot, and caches that path. # # Later when processing inode 258, it first processes its new reference # that has the path of "/A", which results in orphanizing inode 260 # because there is a a path collision. This results in issuing a rename # operation from "/A" to "/o260-6-0". # # Finally when processing the new reference "B/hard_link" for inode 258, # it notices that it collides with inode 259 (not yet processed, because # it has a higher inode number), since that inode has the name # "hard_link" under the directory inode 260. It also checks that inode # 259 has two hardlinks, so it decides to issue a unlink operation for # the name "hard_link" for inode 259. However the path passed to the # unlink operation is "/A/hard_link", which is incorrect since currently # "/A" does not exists, due to the orphanization of inode 260 mentioned # before. The path is incorrect because it was computed and cached # before the orphanization. This results in the receiver to fail with # the above error. btrfs receive -f /tmp/snap2.send $MNT umount $MNT When running the test, it fails like this: $ ./test-send-unlink.sh Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap1' At subvol /mnt/sdi/snap1 Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap2' At subvol /mnt/sdi/snap2 At subvol snap1 At snapshot snap2 ERROR: unlink A/hard_link failed: No such file or directory Fix this by recomputing a path before issuing an unlink operation when processing the new references for the current inode if we previously have orphanized a directory. A test case for fstests will follow soon. CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
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- 21 Jun, 2021 7 commits
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David Sterba authored
Function wait_current_trans_commit_start is now fairly trivial so it can be inlined in its only caller. Reviewed-by:
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David Sterba authored
There's only one caller left btrfs_ioctl_start_sync that passes 0, so we can remove the switch in btrfs_commit_transaction_async. A cleanup 9babda9f ("btrfs: Remove async_transid from btrfs_mksubvol/create_subvol/create_snapshot") removed calls that passed 1, so this is a followup. As this removes last call of wait_current_trans_commit_start_and_unblock, remove the function as well. Reviewed-by:
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Nathan Chancellor authored
clang warns: fs/btrfs/delayed-inode.c:684:6: warning: variable 'total_data_size' set but not used [-Wunused-but-set-variable] int total_data_size = 0, total_size = 0; ^ 1 warning generated. This variable's value has been unused since commit fc0d82e1 ("btrfs: sink total_data parameter in setup_items_for_insert"). Eliminate it. Link: https://github.com/ClangBuiltLinux/linux/issues/1391Reviewed-by:
Nathan Chancellor <nathan@kernel.org> Reviewed-by:
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Nikolay Borisov authored
By way of inverting the list_empty conditional the insert label can be eliminated, making the function's flow entirely linear. Signed-off-by:
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Qu Wenruo authored
[BUG] There is a very rare ASSERT() triggering during full fstests run for subpage rw support. No other reproducer so far. The ASSERT() gets triggered for metadata read in btrfs_page_set_uptodate() inside end_page_read(). [CAUSE] There is still a small race window for metadata only, the race could happen like this: T1 | T2 ------------------------------------+----------------------------- end_bio_extent_readpage() | |- btrfs_validate_metadata_buffer() | | |- free_extent_buffer() | | Still have 2 refs | |- end_page_read() | |- if (unlikely(PagePrivate()) | | The page still has Private | | | free_extent_buffer() | | | Only one ref 1, will be | | | released | | |- detach_extent_buffer_page() | | |- btrfs_detach_subpage() |- btrfs_set_page_uptodate() | The page no longer has Private| >>> ASSERT() triggered <<< | This race window is super small, thus pretty hard to hit, even with so many runs of fstests. But the race window is still there, we have to go another way to solve it other than relying on random PagePrivate() check. Data path is not affected, as it will lock the page before reading, while unlocking the page after the last read has finished, thus no race window. [FIX] This patch will fix the bug by repurposing btrfs_subpage::readers. Now btrfs_subpage::readers will be a member shared by both metadata and data. For metadata path, we don't do the page unlock as metadata only relies on extent locking. At the same time, teach page_range_has_eb() to take btrfs_subpage::readers into consideration. So that even if the last eb of a page gets freed, page::private won't be detached as long as there still are pending end_page_read() calls. By this we eliminate the race window, this will slight increase the metadata memory usage, as the page may not be released as frequently as usual. But it should not be a big deal. The code got introduced in ("btrfs: submit read time repair only for each corrupted sector"), but the fix is in a separate patch to keep the problem description and the crash is rare so it should not hurt bisectability. Signed-off-by: -
Qu Wenruo authored
[BUG] With current btrfs subpage rw support, the following script can lead to fs hang: $ mkfs.btrfs -f -s 4k $dev $ mount $dev -o nospace_cache $mnt $ fsstress -w -n 100 -p 1 -s 1608140256 -v -d $mnt The fs will hang at btrfs_start_ordered_extent(). [CAUSE] In above test case, btrfs_invalidate() will be called with the following parameters: offset = 0 length = 53248 page dirty = 1 subpage dirty bitmap = 0x2000 Since @offset is 0, btrfs_invalidate() will try to invalidate the full page, and finally call clear_page_extent_mapped() which will detach subpage structure from the page. And since the page no longer has subpage structure, the subpage dirty bitmap will be cleared, preventing the dirty range from being written back, thus no way to wake up the ordered extent. [FIX] Just follow other filesystems, only to invalidate the page if the range covers the full page. There are cases like truncate_setsize() which can call btrfs_invalidatepage() with offset == 0 and length != 0 for the last page of an inode. Although the old code will still try to invalidate the full page, we are still safe to just wait for ordered extent to finish. So it shouldn't cause extra problems. Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64] Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64] Signed-off-by:
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Qu Wenruo authored
[BUG] With current subpage RW support, the following script can hang the fs with 64K page size. # mkfs.btrfs -f -s 4k $dev # mount $dev -o nospace_cache $mnt # fsstress -w -n 50 -p 1 -s 1607749395 -d $mnt The kernel will do an infinite loop in btrfs_punch_hole_lock_range(). [CAUSE] In btrfs_punch_hole_lock_range() we: - Truncate page cache range - Lock extent io tree - Wait any ordered extents in the range. We exit the loop until we meet all the following conditions: - No ordered extent in the lock range - No page is in the lock range The latter condition has a pitfall, it only works for sector size == PAGE_SIZE case. While can't handle the following subpage case: 0 32K 64K 96K 128K | |///////||//////| || lockstart=32K lockend=96K - 1 In this case, although the range crosses 2 pages, truncate_pagecache_range() will invalidate no page at all, but only zero the [32K, 96K) range of the two pages. Thus filemap_range_has_page(32K, 96K-1) will always return true, thus we will never meet the loop exit condition. [FIX] Fix the problem by doing page alignment for the lock range. Function filemap_range_has_page() has already handled lend < lstart case, we only need to round up @lockstart, and round_down @lockend for truncate_pagecache_range(). This modification should not change any thing for sector size == PAGE_SIZE case, as in that case our range is already page aligned. Tested-by: Ritesh Harjani <riteshh@linux.ibm.com> # [ppc64] Tested-by: Anand Jain <anand.jain@oracle.com> # [aarch64] Signed-off-by:
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