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path: root/fs/btrfs/transaction.c
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2026-02-26btrfs: use the correct type to initialize block reserve for delayed refsFilipe Manana
[ Upstream commit 2155d0c0a761a56ce7ede83a26eb23ea0f935260 ] When initializing the delayed refs block reserve for a transaction handle we are passing a type of BTRFS_BLOCK_RSV_DELOPS, which is meant for delayed items and not for delayed refs. The correct type for delayed refs is BTRFS_BLOCK_RSV_DELREFS. On release of any excess space reserved in a local delayed refs reserve, we also should transfer that excess space to the global block reserve (it it's full, we return to the space info for general availability). By initializing a transaction's local delayed refs block reserve with a type of BTRFS_BLOCK_RSV_DELOPS, we were also causing any excess space released from the delayed block reserve (fs_info->delayed_block_rsv, used for delayed inodes and items) to be transferred to the global block reserve instead of the global delayed refs block reserve. This was an unintentional change in commit 28270e25c69a ("btrfs: always reserve space for delayed refs when starting transaction"), but it's not particularly serious as things tend to cancel out each other most of the time and it's relatively rare to be anywhere near exhaustion of the global reserve. Fix this by initializing a transaction's local delayed refs reserve with a type of BTRFS_BLOCK_RSV_DELREFS and making btrfs_block_rsv_release() attempt to transfer unused space from such a reserve into the global block reserve, just as we did before that commit for when the block reserve is a delayed refs rsv. Reported-by: Alex Lyakas <alex.lyakas@zadara.com> Link: https://lore.kernel.org/linux-btrfs/CAOcd+r0FHG5LWzTSu=LknwSoqxfw+C00gFAW7fuX71+Z5AfEew@mail.gmail.com/ Fixes: 28270e25c69a ("btrfs: always reserve space for delayed refs when starting transaction") Reviewed-by: Alex Lyakas <alex.lyakas@zadara.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-26btrfs: fix block_group_tree dirty_list corruptionBoris Burkov
[ Upstream commit 3a1f4264daed4b419c325a7fe35e756cada3cf82 ] When the incompat flag EXTENT_TREE_V2 is set, we unconditionally add the block group tree to the switch_commits list before calling switch_commit_roots, as we do for the tree root and the chunk root. However, the block group tree uses normal root dirty tracking and in any transaction that does an allocation and dirties a block group, the block group root will already be linked to a list by the dirty_list field and this use of list_add_tail() is invalid and corrupts the prev/next members of block_group_root->dirty_list. This is apparent on a subsequent list_del on the prev if we enable CONFIG_DEBUG_LIST: [32.1571] ------------[ cut here ]------------ [32.1572] list_del corruption. next->prev should beffff958890202538, but was ffff9588992bd538. (next=ffff958890201538) [32.1575] WARNING: lib/list_debug.c:65 at 0x0, CPU#3: sync/607 [32.1583] CPU: 3 UID: 0 PID: 607 Comm: sync Not tainted 6.18.0 #24PREEMPT(none) [32.1585] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS1.17.0-4.fc41 04/01/2014 [32.1587] RIP: 0010:__list_del_entry_valid_or_report+0x108/0x120 [32.1593] RSP: 0018:ffffaa288287fdd0 EFLAGS: 00010202 [32.1594] RAX: 0000000000000001 RBX: ffff95889326e800 RCX:ffff958890201538 [32.1596] RDX: ffff9588992bd538 RSI: ffff958890202538 RDI:ffffffff82a41e00 [32.1597] RBP: ffff958890202538 R08: ffffffff828fc1e8 R09:00000000ffffefff [32.1599] R10: ffffffff8288c200 R11: ffffffff828e4200 R12:ffff958890201538 [32.1601] R13: ffff95889326e958 R14: ffff958895c24000 R15:ffff958890202538 [32.1603] FS: 00007f0c28eb5740(0000) GS:ffff958af2bd2000(0000)knlGS:0000000000000000 [32.1605] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [32.1607] CR2: 00007f0c28e8a3cc CR3: 0000000109942005 CR4:0000000000370ef0 [32.1609] Call Trace: [32.1610] <TASK> [32.1611] switch_commit_roots+0x82/0x1d0 [btrfs] [32.1615] btrfs_commit_transaction+0x968/0x1550 [btrfs] [32.1618] ? btrfs_attach_transaction_barrier+0x23/0x60 [btrfs] [32.1621] __iterate_supers+0xe8/0x190 [32.1622] ? __pfx_sync_fs_one_sb+0x10/0x10 [32.1623] ksys_sync+0x63/0xb0 [32.1624] __do_sys_sync+0xe/0x20 [32.1625] do_syscall_64+0x73/0x450 [32.1626] entry_SYSCALL_64_after_hwframe+0x76/0x7e [32.1627] RIP: 0033:0x7f0c28d05d2b [32.1632] RSP: 002b:00007ffc9d988048 EFLAGS: 00000246 ORIG_RAX:00000000000000a2 [32.1634] RAX: ffffffffffffffda RBX: 00007ffc9d988228 RCX:00007f0c28d05d2b [32.1636] RDX: 00007f0c28e02301 RSI: 00007ffc9d989b21 RDI:00007f0c28dba90d [32.1637] RBP: 0000000000000001 R08: 0000000000000001 R09:0000000000000000 [32.1639] R10: 0000000000000000 R11: 0000000000000246 R12:000055b96572cb80 [32.1641] R13: 000055b96572b19f R14: 00007f0c28dfa434 R15:000055b96572b034 [32.1643] </TASK> [32.1644] irq event stamp: 0 [32.1644] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [32.1646] hardirqs last disabled at (0): [<ffffffff81298817>]copy_process+0xb37/0x2260 [32.1648] softirqs last enabled at (0): [<ffffffff81298817>]copy_process+0xb37/0x2260 [32.1650] softirqs last disabled at (0): [<0000000000000000>] 0x0 [32.1652] ---[ end trace 0000000000000000 ]--- Furthermore, this list corruption eventually (when we happen to add a new block group) results in getting the switch_commits and dirty_cowonly_roots lists mixed up and attempting to call update_root on the tree root which can't be found in the tree root, resulting in a transaction abort: [87.8269] BTRFS critical (device nvme1n1): unable to find root key (1 0 0) in tree 1 [87.8272] ------------[ cut here ]------------ [87.8274] BTRFS: Transaction aborted (error -117) [87.8275] WARNING: fs/btrfs/root-tree.c:153 at 0x0, CPU#4: sync/703 [87.8285] CPU: 4 UID: 0 PID: 703 Comm: sync Not tainted 6.18.0 #25 PREEMPT(none) [87.8287] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-4.fc41 04/01/2014 [87.8289] RIP: 0010:btrfs_update_root+0x296/0x790 [btrfs] [87.8295] RSP: 0018:ffffa58d035dfd60 EFLAGS: 00010282 [87.8297] RAX: ffff9a59126ddb68 RBX: ffff9a59126dc000 RCX: 0000000000000000 [87.8299] RDX: 0000000000000000 RSI: 00000000ffffff8b RDI: ffffffffc0b28270 [87.8301] RBP: ffff9a5904aec000 R08: 0000000000000000 R09: 00000000ffffefff [87.8303] R10: ffffffff9ac8c200 R11: ffffffff9ace4200 R12: 0000000000000001 [87.8305] R13: ffff9a59041740e8 R14: ffff9a5904aec1f7 R15: ffff9a590fdefaf0 [87.8307] FS: 00007f54cde6b740(0000) GS:ffff9a5b5a81c000(0000) knlGS:0000000000000000 [87.8309] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [87.8310] CR2: 00007f54cde403cc CR3: 0000000112902004 CR4: 0000000000370ef0 [87.8312] Call Trace: [87.8313] <TASK> [87.8314] ? _raw_spin_unlock+0x23/0x40 [87.8315] commit_cowonly_roots+0x1ad/0x250 [btrfs] [87.8317] ? btrfs_commit_transaction+0x79b/0x1560 [btrfs] [87.8320] btrfs_commit_transaction+0x8aa/0x1560 [btrfs] [87.8322] ? btrfs_attach_transaction_barrier+0x23/0x60 [btrfs] [87.8325] __iterate_supers+0xf1/0x170 [87.8326] ? __pfx_sync_fs_one_sb+0x10/0x10 [87.8327] ksys_sync+0x63/0xb0 [87.8328] __do_sys_sync+0xe/0x20 [87.8329] do_syscall_64+0x73/0x450 [87.8330] entry_SYSCALL_64_after_hwframe+0x76/0x7e [87.8331] RIP: 0033:0x7f54cdd05d2b [87.8336] RSP: 002b:00007fff1b58ff78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 [87.8338] RAX: ffffffffffffffda RBX: 00007fff1b590158 RCX: 00007f54cdd05d2b [87.8340] RDX: 00007f54cde02301 RSI: 00007fff1b592b66 RDI: 00007f54cddba90d [87.8342] RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 [87.8344] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e07ca96b80 [87.8346] R13: 000055e07ca9519f R14: 00007f54cddfa434 R15: 000055e07ca95034 [87.8348] </TASK> [87.8348] irq event stamp: 0 [87.8349] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [87.8351] hardirqs last disabled at (0): [<ffffffff99698797>] copy_process+0xb37/0x21e0 [87.8353] softirqs last enabled at (0): [<ffffffff99698797>] copy_process+0xb37/0x21e0 [87.8355] softirqs last disabled at (0): [<0000000000000000>] 0x0 [87.8357] ---[ end trace 0000000000000000 ]--- [87.8358] BTRFS: error (device nvme1n1 state A) in btrfs_update_root:153: errno=-117 Filesystem corrupted [87.8360] BTRFS info (device nvme1n1 state EA): forced readonly [87.8362] BTRFS warning (device nvme1n1 state EA): Skipping commit of aborted transaction. [87.8364] BTRFS: error (device nvme1n1 state EA) in cleanup_transaction:2037: errno=-117 Filesystem corrupted Since the block group tree was pulled out of the extent tree and uses normal root dirty tracking, remove the offending extra list_add. This fixes the list corruption and the resulting fs corruption. Fixes: 14033b08a029 ("btrfs: don't save block group root into super block") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-26btrfs: headers cleanup to remove unnecessary local includesQu Wenruo
[ Upstream commit c5667f9c8eb90293dfa4e52c65eb89fe39f5652d ] [BUG] When I tried to remove btrfs_bio::fs_info and use btrfs_bio::inode to grab the fs_info, the header "btrfs_inode.h" is needed to access the full btrfs_inode structure. Then btrfs will fail to compile. [CAUSE] There is a recursive including chain: "bio.h" -> "btrfs_inode.h" -> "extent_map.h" -> "compression.h" -> "bio.h" That recursive including is causing problems for btrfs. [ENHANCEMENT] To reduce the risk of recursive including: - Remove unnecessary local includes from btrfs headers Either the included header is pulled in by other headers, or is completely unnecessary. - Remove btrfs local includes if the header only requires a pointer In that case let the implementing C file to pull the required header. This is especially important for headers like "btrfs_inode.h" which pulls in a lot of other btrfs headers, thus it's a mine field of recursive including. - Remove unnecessary temporary structure definition Either if we have included the header defining the structure, or completely unused. Now including "btrfs_inode.h" inside "bio.h" is completely fine, although "btrfs_inode.h" still includes "extent_map.h", but that header only includes "fs.h", no more chain back to "bio.h". Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: b39b26e017c7 ("btrfs: zoned: don't zone append to conventional zone") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23btrfs: fix deadlock in wait_current_trans() due to ignored transaction typeRobbie Ko
commit 5037b342825df7094a4906d1e2a9674baab50cb2 upstream. When wait_current_trans() is called during start_transaction(), it currently waits for a blocked transaction without considering whether the given transaction type actually needs to wait for that particular transaction state. The btrfs_blocked_trans_types[] array already defines which transaction types should wait for which transaction states, but this check was missing in wait_current_trans(). This can lead to a deadlock scenario involving two transactions and pending ordered extents: 1. Transaction A is in TRANS_STATE_COMMIT_DOING state 2. A worker processing an ordered extent calls start_transaction() with TRANS_JOIN 3. join_transaction() returns -EBUSY because Transaction A is in TRANS_STATE_COMMIT_DOING 4. Transaction A moves to TRANS_STATE_UNBLOCKED and completes 5. A new Transaction B is created (TRANS_STATE_RUNNING) 6. The ordered extent from step 2 is added to Transaction B's pending ordered extents 7. Transaction B immediately starts commit by another task and enters TRANS_STATE_COMMIT_START 8. The worker finally reaches wait_current_trans(), sees Transaction B in TRANS_STATE_COMMIT_START (a blocked state), and waits unconditionally 9. However, TRANS_JOIN should NOT wait for TRANS_STATE_COMMIT_START according to btrfs_blocked_trans_types[] 10. Transaction B is waiting for pending ordered extents to complete 11. Deadlock: Transaction B waits for ordered extent, ordered extent waits for Transaction B This can be illustrated by the following call stacks: CPU0 CPU1 btrfs_finish_ordered_io() start_transaction(TRANS_JOIN) join_transaction() # -EBUSY (Transaction A is # TRANS_STATE_COMMIT_DOING) # Transaction A completes # Transaction B created # ordered extent added to # Transaction B's pending list btrfs_commit_transaction() # Transaction B enters # TRANS_STATE_COMMIT_START # waiting for pending ordered # extents wait_current_trans() # waits for Transaction B # (should not wait!) Task bstore_kv_sync in btrfs_commit_transaction waiting for ordered extents: __schedule+0x2e7/0x8a0 schedule+0x64/0xe0 btrfs_commit_transaction+0xbf7/0xda0 [btrfs] btrfs_sync_file+0x342/0x4d0 [btrfs] __x64_sys_fdatasync+0x4b/0x80 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Task kworker in wait_current_trans waiting for transaction commit: Workqueue: btrfs-syno_nocow btrfs_work_helper [btrfs] __schedule+0x2e7/0x8a0 schedule+0x64/0xe0 wait_current_trans+0xb0/0x110 [btrfs] start_transaction+0x346/0x5b0 [btrfs] btrfs_finish_ordered_io.isra.0+0x49b/0x9c0 [btrfs] btrfs_work_helper+0xe8/0x350 [btrfs] process_one_work+0x1d3/0x3c0 worker_thread+0x4d/0x3e0 kthread+0x12d/0x150 ret_from_fork+0x1f/0x30 Fix this by passing the transaction type to wait_current_trans() and checking btrfs_blocked_trans_types[cur_trans->state] against the given type before deciding to wait. This ensures that transaction types which are allowed to join during certain blocked states will not unnecessarily wait and cause deadlocks. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Cc: Motiejus Jakštys <motiejus@jakstys.lt> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-23btrfs: use smp_mb__after_atomic() when forcing COW in create_pending_snapshot()Filipe Manana
After setting the BTRFS_ROOT_FORCE_COW flag on the root we are doing a full write barrier, smp_wmb(), but we don't need to, all we need is a smp_mb__after_atomic(). The use of the smp_wmb() is from the old days when we didn't use a bit and used instead an int field in the root to signal if cow is forced. After the int field was changed to a bit in the root's state (flags field), we forgot to update the memory barrier in create_pending_snapshot() to smp_mb__after_atomic(), but we did the change in commit_fs_roots() after clearing BTRFS_ROOT_FORCE_COW. That happened in commit 27cdeb7096b8 ("Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root"). On the reader side, in should_cow_block(), we also use the counterpart smp_mb__before_atomic() which generates further confusion. So change the smp_wmb() to smp_mb__after_atomic(). In fact we don't even need any barrier at all since create_pending_snapshot() is called in the critical section of a transaction commit and therefore no one can concurrently join/attach the transaction, or start a new one, until the transaction is unblocked. By the time someone starts a new transaction and enters should_cow_block(), a lot of implicit memory barriers already took place by having acquired several locks such as fs_info->trans_lock and extent buffer locks on the root node at least. Nevertlheless, for consistency use smp_mb__after_atomic() after setting the force cow bit in create_pending_snapshot(). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-09-23btrfs: add unlikely annotations to branches leading to transaction abortDavid Sterba
The unlikely() annotation is a static prediction hint that compiler may use to reorder code out of hot path. We use it elsewhere (namely tree-checker.c) for error branches that almost never happen. Transaction abort is one such error, the btrfs_abort_transaction() inlines code to check the state and print a warning, this ought to be out of the hot path. The most common pattern is when transaction abort is called after checking a return value and the control flow leads to a quick return. In other cases it may not be necessary to add unlikely() e.g. when the function returns anyway or the control flow is not changed noticeably. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-09-23btrfs: more trivial BTRFS_PATH_AUTO_FREE conversionsSun YangKai
Trivial pattern for the auto freeing with goto -> return conversions if possible. The following cases are considered trivial in this patch: 1. Cases where there are no operations between btrfs_free_path() and the function returns. 2. Cases where only simple cleanup operations (such as kfree(), kvfree(), clear_bit(), and fs_path_free()) are present between btrfs_free_path() and the function return. Signed-off-by: Sun YangKai <sunk67188@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-09-23btrfs: remove pointless key offset setup in create_pending_snapshot()Filipe Manana
There's no point in setting the key's offset to (u64)-1 since we never use it before setting it to the current transaction's ID. So remove the assignment of (u64)-1 to the key's offset and move the remainder of the key initialization close to where it's used. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-09-23btrfs: fix typos in comments and stringsDavid Sterba
Annual typo fixing pass. Strangely codespell found only about 30% of what is in this patch, the rest was done manually using text spellchecker with a custom dictionary of acceptable terms. Reviewed-by: Neal Gompa <neal@gompa.dev> Signed-off-by: David Sterba <dsterba@suse.com>
2025-09-22btrfs: convert several int parameters to boolDavid Sterba
We're almost done cleaning misused int/bool parameters. Convert a bunch of them, found by manual grepping. Note that btrfs_sync_fs() needs an int as it's mandated by the struct super_operations prototype. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2025-07-22btrfs: qgroup: fix qgroup create ioctl returning success after quotas disabledFilipe Manana
When quotas are disabled qgroup ioctls are supposed to return -ENOTCONN, but the qgroup create ioctl stopped doing that when it races with a quota disable operation, returning 0 instead. This change of behaviour happened in commit 6ed05643ddb1 ("btrfs: create qgroup earlier in snapshot creation"). The issue happens as follows: 1) Task A enters btrfs_ioctl_qgroup_create(), qgroups are enabled and so qgroup_enabled() returns true since fs_info->quota_root is not NULL; 2) Task B enters btrfs_ioctl_quota_ctl() -> btrfs_quota_disable() and disables qgroups, so now fs_info->quota_root is NULL; 3) Task A enters btrfs_create_qgroup() and calls btrfs_qgroup_mode(), which returns BTRFS_QGROUP_MODE_DISABLED since quotas are disabled, and then btrfs_create_qgroup() returns 0 to the caller, which makes the ioctl return 0 instead of -ENOTCONN. The check for fs_info->quota_root and returning -ENOTCONN if it's NULL is made only after the call btrfs_qgroup_mode(). Fix this by moving the check for disabled quotas with btrfs_qgroup_mode() into transaction.c:create_pending_snapshot(), so that we don't abort the transaction if btrfs_create_qgroup() returns -ENOTCONN and quotas are disabled. Fixes: 6ed05643ddb1 ("btrfs: create qgroup earlier in snapshot creation") CC: stable@vger.kernel.org # 6.12+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-07-21btrfs: tree-log: add and rename extent bits for dirty_log_pages treeDavid Sterba
The dirty_log_pages tree is used for tree logging and marks extents based on log_transid. The bits could be renamed to resemble the LOG1/LOG2 naming used for the BTRFS_FS_LOG1_ERR bits. The DIRTY bit is renamed to LOG1 and NEW to LOG2. Signed-off-by: David Sterba <dsterba@suse.com>
2025-07-21btrfs: rename err to ret in btrfs_wait_tree_log_extents()David Sterba
Unify naming of return value to the preferred way. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-07-21btrfs: rename err to ret in btrfs_wait_extents()David Sterba
Unify naming of return value to the preferred way. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-07-21btrfs: sysfs: track current commit duration in commit_statsBoris Burkov
When debugging/detecting outlier commit stalls, having an indicator that we are currently in a long commit critical section can be very useful. Extend the commit_stats sysfs file to also include the current commit critical section duration. Since this requires storing the last commit start time, use that rather than a separate stack variable for storing the finished commit durations as well. This also requires slightly moving up the timing of the stats updating to *inside* the critical section to avoid the transaction T+1 setting the critical_section_start_time to 0 before transaction T can update its stats, which would trigger the new ASSERT. This is an improvement in and of itself, as it makes the stats more accurately represent the true critical section time. It may be yet better to pull the stats up to where start_transaction gets unblocked, rather than the next commit, but this seems like a good enough place as well. Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: simplify cow only root list extraction during transaction commitFilipe Manana
There's no need to keep a local variable to extract the first member of the list and then do a list_entry() call, we can use list_first_entry() instead, removing the need for the temporary variable and extracting the first element in a single step. Also, there's no need to do a list_del_init() followed by list_add_tail(), instead we can use list_move_tail(). We are in transaction commit critical section where we don't need to worry about concurrency and that's why we don't take any locks and can use list_move_tail() (we do assert early at commit_cowonly_roots() that we are in the critical section, that the transaction's state is TRANS_STATE_COMMIT_DOING). Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: simplify getting and extracting previous transaction during commitFilipe Manana
Instead of detecting if there is a previous transaction by comparing the current transaction's list prev member to the head of the transaction list (fs_info->trans_list), use the list_is_first() helper which contains that logic and the naming makes sense since a new transaction is always added to the end of the list fs_info->trans_list with list_add_tail(). And instead of extracting the previous transaction with the more generic list_entry() helper against the current transaction's list prev member, use the more specific list_prev_entry() helper, which makes it clear what we are doing and is shorter. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: add space_info argument to btrfs_chunk_alloc()Naohiro Aota
Take a btrfs_space_info argument in btrfs_chunk_alloc(). New block group will belong to that space_info. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: don't BUG_ON() when unpinning extents during transaction commitFilipe Manana
In the final phase of a transaction commit, when unpinning extents at btrfs_finish_extent_commit(), there's no need to BUG_ON() if we fail to unpin an extent range. All that can happen is that we fail to return the extent range to the in-memory free space cache, meaning no future space allocations can reuse that extent range while the fs is mounted. So instead return the error to the caller and make it abort the transaction, so that the error is noticed and prevent misteriously leaking space. We keep track of the first error we get while unpinning an extent range and keep trying to unpin all the following extent ranges, so that we attempt to do all discards. The transaction abort will deal with all resource cleanups. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: use buffer xarray for extent buffer writeback operationsJosef Bacik
Currently we have this ugly back and forth with the btree writeback where we find the folio, find the eb associated with that folio, and then attempt to writeback. This results in two different paths for subpage ebs and >= page size ebs. Clean this up by adding our own infrastructure around looking up tagged ebs and writing the ebs out directly. This allows us to unify the subpage and >= pagesize IO paths, resulting in a much cleaner writeback path for extent buffers. I ran this through fsperf on a VM with 8 CPUs and 16GiB of RAM. I used smallfiles100k, but reduced the files to 1k to make it run faster, the results are as follows, with the statistically significant improvements marked with *, there were no regressions. fsperf was run with -n 10 for both runs, so the baseline is the average 10 runs and the test is the average of 10 runs. smallfiles100k results metric baseline current stdev diff ================================================================================ avg_commit_ms 68.58 58.44 3.35 -14.79% * commits 270.60 254.70 16.24 -5.88% dev_read_iops 48 48 0 0.00% dev_read_kbytes 1044 1044 0 0.00% dev_write_iops 866117.90 850028.10 14292.20 -1.86% dev_write_kbytes 10939976.40 10605701.20 351330.32 -3.06% elapsed 49.30 33 1.64 -33.06% * end_state_mount_ns 41251498.80 35773220.70 2531205.32 -13.28% * end_state_umount_ns 1.90e+09 1.50e+09 14186226.85 -21.38% * max_commit_ms 139 111.60 9.72 -19.71% * sys_cpu 4.90 3.86 0.88 -21.29% write_bw_bytes 42935768.20 64318451.10 1609415.05 49.80% * write_clat_ns_mean 366431.69 243202.60 14161.98 -33.63% * write_clat_ns_p50 49203.20 20992 264.40 -57.34% * write_clat_ns_p99 827392 653721.60 65904.74 -20.99% * write_io_kbytes 2035940 2035940 0 0.00% write_iops 10482.37 15702.75 392.92 49.80% * write_lat_ns_max 1.01e+08 90516129 3910102.06 -10.29% * write_lat_ns_mean 366556.19 243308.48 14154.51 -33.62% * As you can see we get about a 33% decrease runtime, with a 50% throughput increase, which is pretty significant. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: trivial conversion to return bool instead of intDavid Sterba
Old code has a lot of int for bool return values, bool is recommended and done in new code. Convert the trivial cases that do simple 0/false and 1/true. Functions comment are updated if needed. Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: rename remaining exported functions from extent-io-tree.hFilipe Manana
Rename the remaning exported functions that don't have a 'btrfs_' prefix. By convention exported functions should have such prefix to make it clear they are btrfs specific and to avoid collisions with functions from elsewhere in the kernel. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: rename free_extent_state() to include a btrfs prefixFilipe Manana
This is an exported function so it should have a 'btrfs_' prefix by convention, to make it clear it's btrfs specific and to avoid collisions with functions from elsewhere in the kernel. Rename the function to add 'btrfs_' prefix to it. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: rename the functions to init and release an extent io treeFilipe Manana
These functions are exported so they should have a 'btrfs_' prefix by convention, to make it clear they are btrfs specific and to avoid collisions with functions from elsewhere in the kernel. So add a 'btrfs_' prefix to their name to make it clear they are from btrfs. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: rename the functions to search for bits in extent rangesFilipe Manana
These functions are exported so they should have a 'btrfs_' prefix by convention, to make it clear they are btrfs specific and to avoid collisions with functions from elsewhere in the kernel. So add a 'btrfs_' prefix to their name to make it clear they are from btrfs. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-05-15btrfs: rename the functions to clear bits for an extent rangeFilipe Manana
These functions are exported so they should have a 'btrfs_' prefix by convention, to make it clear they are btrfs specific and to avoid collisions with functions from elsewhere in the kernel. One of them has a double underscore prefix which is also discouraged. So remove double underscore prefix where applicable and add a 'btrfs_' prefix to their name to make it clear they are from btrfs. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: explicitly ref count block_group on new_bgs listBoris Burkov
All other users of the bg_list list_head increment the refcount when adding to a list and decrement it when deleting from the list. Just for the sake of uniformity and to try to avoid refcounting bugs, do it for this list as well. This does not fix any known ref-counting bug, as the reference belongs to a single task (trans_handle is not shared and this represents trans_handle->new_bgs linkage) and will not lose its original refcount while that thread is running. And BLOCK_GROUP_FLAG_NEW protects against ref-counting errors "moving" the block group to the unused list without taking a ref. With that said, I still believe it is simpler to just hold the extra ref count for this list user as well. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: harden block_group::bg_list against list_del() racesBoris Burkov
As far as I can tell, these calls of list_del_init() on bg_list cannot run concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(), as they are in transaction error paths and situations where the block group is readonly. However, if there is any chance at all of racing with mark_bg_unused(), or a different future user of bg_list, better to be safe than sorry. Otherwise we risk the following interleaving (bg_list refcount in parens) T1 (some random op) T2 (btrfs_mark_bg_unused) !list_empty(&bg->bg_list); (1) list_del_init(&bg->bg_list); (1) list_move_tail (1) btrfs_put_block_group (0) btrfs_delete_unused_bgs bg = list_first_entry list_del_init(&bg->bg_list); btrfs_put_block_group(bg); (-1) Ultimately, this results in a broken ref count that hits zero one deref early and the real final deref underflows the refcount, resulting in a WARNING. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: use struct btrfs_inode inside create_pending_snapshot()David Sterba
Use a struct btrfs_inode in create_pending_snapshot() as it's an internal helper, allowing to remove some use of BTRFS_I. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: unify ordering of btrfs_key initializationsDavid Sterba
The btrfs_key is defined as objectid/type/offset and the keys are also printed like that. For better readability, update all key initializations to match this order. Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23btrfs: fix use-after-free when attempting to join an aborted transactionFilipe Manana
When we are trying to join the current transaction and if it's aborted, we read its 'aborted' field after unlocking fs_info->trans_lock and without holding any extra reference count on it. This means that a concurrent task that is aborting the transaction may free the transaction before we read its 'aborted' field, leading to a use-after-free. Fix this by reading the 'aborted' field while holding fs_info->trans_lock since any freeing task must first acquire that lock and set fs_info->running_transaction to NULL before freeing the transaction. This was reported by syzbot and Dmitry with the following stack traces from KASAN: ================================================================== BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128 CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_data_space Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803 btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5315: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_creat fs/open.c:1495 [inline] __se_sys_creat fs/open.c:1489 [inline] __x64_sys_creat+0x123/0x170 fs/open.c:1489 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5336: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 cleanup_transaction fs/btrfs/transaction.c:2063 [inline] btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598 insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757 btrfs_balance+0x992/0x10c0 fs/btrfs/volumes.c:4633 btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888011839000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 36 bytes inside of freed 2048-byte region [ffff888011839000, ffff888011839800) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11838 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002 raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002 head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea0000460e01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 57, tgid 57 (kworker/0:2), ts 67248182943, free_ts 67229742023 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269 alloc_slab_page+0x6a/0x110 mm/slub.c:2423 allocate_slab+0x5a/0x2b0 mm/slub.c:2589 new_slab mm/slub.c:2642 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830 __slab_alloc+0x58/0xa0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_node_track_caller_noprof+0x2e9/0x4c0 mm/slub.c:4317 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2884 sock_alloc_send_skb include/net/sock.h:1803 [inline] mld_newpack+0x1c3/0xaf0 net/ipv6/mcast.c:1747 add_grhead net/ipv6/mcast.c:1850 [inline] add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988 mld_send_cr net/ipv6/mcast.c:2114 [inline] mld_ifc_work+0x691/0xd90 net/ipv6/mcast.c:2651 page last free pid 5300 tgid 5300 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659 __slab_free+0x2c2/0x380 mm/slub.c:4524 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] __do_kmalloc_node mm/slub.c:4297 [inline] __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] fib_create_info+0xc14/0x25b0 net/ipv4/fib_semantics.c:1435 fib_table_insert+0x1f6/0x1f20 net/ipv4/fib_trie.c:1231 fib_magic+0x3d8/0x620 net/ipv4/fib_frontend.c:1112 fib_add_ifaddr+0x40c/0x5e0 net/ipv4/fib_frontend.c:1156 fib_netdev_event+0x375/0x490 net/ipv4/fib_frontend.c:1494 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x207/0x400 dev_change_flags+0xf0/0x1a0 net/core/dev.c:9045 do_setlink+0xc90/0x4210 net/core/rtnetlink.c:3109 rtnl_changelink net/core/rtnetlink.c:3723 [inline] __rtnl_newlink net/core/rtnetlink.c:3875 [inline] rtnl_newlink+0x1bb6/0x2210 net/core/rtnetlink.c:4012 Memory state around the buggy address: ffff888011838f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888011838f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888011839000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888011839080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888011839100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: syzbot+45212e9d87a98c3f5b42@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/678e7da5.050a0220.303755.007c.GAE@google.com/ Reported-by: Dmitry Vyukov <dvyukov@google.com> Link: https://lore.kernel.org/linux-btrfs/CACT4Y+ZFBdo7pT8L2AzM=vegZwjp-wNkVJZQf0Ta3vZqtExaSw@mail.gmail.com/ Fixes: 871383be592b ("btrfs: add missing unlocks to transaction abort paths") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13btrfs: drop fs_info argument from btrfs_update_space_info_*()Naohiro Aota
Since commit e1e577aafe41 ("btrfs: store fs_info in space_info"), we have the fs_info in a space_info. So, we can drop fs_info argument from btrfs_update_space_info_*. There is no behavior change. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: track delayed ref heads in an xarrayFilipe Manana
Currently we use a red black tree (rb-tree) to track the delayed ref heads (in struct btrfs_delayed_ref_root::href_root). This however is not very efficient when the number of delayed ref heads is large (and it's very common to be at least in the order of thousands) since rb-trees are binary trees. For example for 10K delayed ref heads, the tree has a depth of 13. Besides that, inserting into the tree requires navigating through it and pulling useless cache lines in the process since the red black tree nodes are embedded within the delayed ref head structure - on the other hand, by being embedded, it requires no extra memory allocations. We can improve this by using an xarray instead which has a much higher branching factor than a red black tree (binary balanced tree) and is more cache friendly and behaves like a resizable array, with a much better search and insertion complexity than a red black tree. This only has one small disadvantage which is that insertion will sometimes require allocating memory for the xarray - which may fail (not that often since it uses a kmem_cache) - but on the other hand we can reduce the delayed ref head structure size by 24 bytes (from 152 down to 128 bytes) after removing the embedded red black tree node, meaning than we can now fit 32 delayed ref heads per 4K page instead of 26, and that gain compensates for the occasional memory allocations needed for the xarray nodes. We also end up using only 2 cache lines instead of 3 per delayed ref head. Running the following fs_mark test showed some improvements: $ cat test.sh #!/bin/bash DEV=/dev/nullb0 MNT=/mnt/nullb0 MOUNT_OPTIONS="-o ssd" FILES=100000 THREADS=$(nproc --all) echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor mkfs.btrfs -f $DEV mount $MOUNT_OPTIONS $DEV $MNT OPTS="-S 0 -L 5 -n $FILES -s 0 -t $THREADS -k" for ((i = 1; i <= $THREADS; i++)); do OPTS="$OPTS -d $MNT/d$i" done fs_mark $OPTS umount $MNT Before this patch: FSUse% Count Size Files/sec App Overhead 10 1200000 0 171845.7 12253839 16 2400000 0 230898.7 12308254 23 3600000 0 212292.9 12467768 30 4800000 0 195737.8 12627554 46 6000000 0 171055.2 12783329 After this patch: FSUse% Count Size Files/sec App Overhead 10 1200000 0 173835.0 12246131 16 2400000 0 233537.8 12271746 23 3600000 0 220398.7 12307737 30 4800000 0 204483.6 12392318 40 6000000 0 182923.3 12771843 Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove num_entries atomic counter from delayed ref rootFilipe Manana
The atomic counter 'num_entries' is not used anymore, we increment it and decrement it but then we don't ever read it to use for any logic. Its last use was removed with commit 61a56a992fcf ("btrfs: delayed refs pre-flushing should only run the heads we have"). So remove it. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove fs_info parameter from btrfs_cleanup_one_transaction()Filipe Manana
The fs_info parameter is redundant because it can be extracted from the transaction given as another parameter. So remove it and use the fs_info accessible from the transaction. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: qgroup: use xarray to track dirty extents in transactionJunchao Sun
Use xarray to track dirty extents to reduce the size of the struct btrfs_qgroup_extent_record from 64 bytes to 40 bytes. The xarray is more cache line friendly, it also reduces the complexity of insertion and search code compared to rb tree. Another change introduced is about error handling. Before this patch, the result of btrfs_qgroup_trace_extent_nolock() is always a success. In this patch, because of this function calls the function xa_store() which has the possibility to fail, so mark qgroup as inconsistent if error happened and then free preallocated memory. Also we preallocate memory before spin_lock(), if memory preallcation failed, error handling is the same the existing code. Suggested-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Junchao Sun <sunjunchao2870@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11btrfs: fix data race when accessing the last_trans field of a rootFilipe Manana
KCSAN complains about a data race when accessing the last_trans field of a root: [ 199.553628] BUG: KCSAN: data-race in btrfs_record_root_in_trans [btrfs] / record_root_in_trans [btrfs] [ 199.555186] read to 0x000000008801e308 of 8 bytes by task 2812 on cpu 1: [ 199.555210] btrfs_record_root_in_trans+0x9a/0x128 [btrfs] [ 199.555999] start_transaction+0x154/0xcd8 [btrfs] [ 199.556780] btrfs_join_transaction+0x44/0x60 [btrfs] [ 199.557559] btrfs_dirty_inode+0x9c/0x140 [btrfs] [ 199.558339] btrfs_update_time+0x8c/0xb0 [btrfs] [ 199.559123] touch_atime+0x16c/0x1e0 [ 199.559151] pipe_read+0x6a8/0x7d0 [ 199.559179] vfs_read+0x466/0x498 [ 199.559204] ksys_read+0x108/0x150 [ 199.559230] __s390x_sys_read+0x68/0x88 [ 199.559257] do_syscall+0x1c6/0x210 [ 199.559286] __do_syscall+0xc8/0xf0 [ 199.559318] system_call+0x70/0x98 [ 199.559431] write to 0x000000008801e308 of 8 bytes by task 2808 on cpu 0: [ 199.559464] record_root_in_trans+0x196/0x228 [btrfs] [ 199.560236] btrfs_record_root_in_trans+0xfe/0x128 [btrfs] [ 199.561097] start_transaction+0x154/0xcd8 [btrfs] [ 199.561927] btrfs_join_transaction+0x44/0x60 [btrfs] [ 199.562700] btrfs_dirty_inode+0x9c/0x140 [btrfs] [ 199.563493] btrfs_update_time+0x8c/0xb0 [btrfs] [ 199.564277] file_update_time+0xb8/0xf0 [ 199.564301] pipe_write+0x8ac/0xab8 [ 199.564326] vfs_write+0x33c/0x588 [ 199.564349] ksys_write+0x108/0x150 [ 199.564372] __s390x_sys_write+0x68/0x88 [ 199.564397] do_syscall+0x1c6/0x210 [ 199.564424] __do_syscall+0xc8/0xf0 [ 199.564452] system_call+0x70/0x98 This is because we update and read last_trans concurrently without any type of synchronization. This should be generally harmless and in the worst case it can make us do extra locking (btrfs_record_root_in_trans()) trigger some warnings at ctree.c or do extra work during relocation - this would probably only happen in case of load or store tearing. So fix this by always reading and updating the field using READ_ONCE() and WRITE_ONCE(), this silences KCSAN and prevents load and store tearing. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11btrfs: switch btrfs_pending_snapshot::dir to btrfs_inodeDavid Sterba
The structure is internal so we should use struct btrfs_inode for that. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11btrfs: add and use helper to commit the current transactionFilipe Manana
We have several places that attach to the current transaction with btrfs_attach_transaction_barrier() and then commit the transaction if there is one. Add a helper and use it to deduplicate this pattern. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-11btrfs: simplify range parameters of btrfs_wait_ordered_roots()David Sterba
The range is specified only in two ways, we can simplify the case for the whole filesystem range as a NULL block group parameter. Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename werr and err to ret in __btrfs_wait_marked_extents()Anand Jain
Rename the function's local return variables err and werr to ret. Also, align the variable declarations with the other declarations in the function for better function space alignment. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename werr and err to ret in btrfs_write_marked_extents()Anand Jain
Rename the function's local variable werr and err to ret. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: report filemap_fdata<write|wait>_range() errorAnand Jain
In the function btrfs_write_marked_extents() and in __btrfs_wait_marked_extents() return the actual error if when filemap_fdata<write|wait>_range() fails. Suggested-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: change root->root_key.objectid to btrfs_root_id()Josef Bacik
A comment from Filipe on one of my previous cleanups brought my attention to a new helper we have for getting the root id of a root, which makes it easier to read in the code. The changes where made with the following Coccinelle semantic patch: // <smpl> @@ expression E,E1; @@ ( E->root_key.objectid = E1 | - E->root_key.objectid + btrfs_root_id(E) ) // </smpl> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor style fixups ] Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: rename err to ret in __btrfs_end_transaction()Anand Jain
Unify naming of return value to the preferred way. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-05-07btrfs: remove pointless BUG_ON() when creating snapshotFilipe Manana
When creating a snapshot we first check with btrfs_lookup_dir_item() if there is a name collision in the parent directory and then return an error if there's a collision. Then later on when trying to insert a dir item for the snapshot we BUG_ON() if the return value is -EEXIST or -EOVERFLOW: static noinline int create_pending_snapshot(...) { (...) /* check if there is a file/dir which has the same name. */ dir_item = btrfs_lookup_dir_item(...); (...) ret = btrfs_insert_dir_item(...); /* We have check then name at the beginning, so it is impossible. */ BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } (...) } It's impossible to get the -EEXIST because we previously checked for a potential collision with btrfs_lookup_dir_item() and we know that after that no one could have added a colliding name because at this point the transaction is in its critical section, state TRANS_STATE_COMMIT_DOING, so no one can join this transaction to add a colliding name and neither can anyone start a new transaction to do that. As for the -EOVERFLOW, that can't happen as long as we have the extended references feature enabled, which is a mkfs default for many years now. In either case, the BUG_ON() is excessive as we can properly deal with any error and can abort the transaction and jump to the 'fail' label, in which case we'll also get the useful stack trace (just like a BUG_ON()) from the abort if the error is either -EEXIST or -EOVERFLOW. So remove the BUG_ON(). Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-04-02btrfs: always clear PERTRANS metadata during commitBoris Burkov
It is possible to clear a root's IN_TRANS tag from the radix tree, but not clear its PERTRANS, if there is some error in between. Eliminate that possibility by moving the free up to where we clear the tag. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-04-02btrfs: qgroup: convert PREALLOC to PERTRANS after record_root_in_transBoris Burkov
The transaction is only able to free PERTRANS reservations for a root once that root has been recorded with the TRANS tag on the roots radix tree. Therefore, until we are sure that this root will get tagged, it isn't safe to convert. Generally, this is not an issue as *some* transaction will likely tag the root before long and this reservation will get freed in that transaction, but technically it could stick around until unmount and result in a warning about leaked metadata reservation space. This path is most exercised by running the generic/269 fstest with CONFIG_BTRFS_DEBUG. Fixes: a6496849671a ("btrfs: fix start transaction qgroup rsv double free") CC: stable@vger.kernel.org # 6.6+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-05btrfs: remove SLAB_MEM_SPREAD flag useChengming Zhou
The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was removed as of v6.8-rc1, so it became a dead flag since the commit 16a1d968358a ("mm/slab: remove mm/slab.c and slab_def.h"). And the series[1] went on to mark it obsolete to avoid confusion for users. Here we can just remove all its users, which has no functional change. [1] https://lore.kernel.org/all/20240223-slab-cleanup-flags-v2-1-02f1753e8303@suse.cz/ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-03-04btrfs: use KMEM_CACHE() to create btrfs_trans_handle cacheKunwu Chan
Use the KMEM_CACHE() macro instead of kmem_cache_create() to simplify the creation of SLAB caches when the default values are used. Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>