talos-obmc-linux/fs, branch v4.18.19

Btrfs: fix use-after-free when dumping free space

2018-11-13T19:12:58+00:00

commit 9084cb6a24bf5838a665af92ded1af8363f9e563 upstream. We were iterating a block group's free space cache rbtree without locking first the lock that protects it (the free_space_ctl->free_space_offset rbtree is protected by the free_space_ctl->tree_lock spinlock). KASAN reported an use-after-free problem when iterating such a rbtree due to a concurrent rbtree delete: [ 9520.359168] ================================================================== [ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90 [ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721 [ 9520.360357] [ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G L 4.19.0-rc8-nbor #555 [ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 9520.362682] Call Trace: [ 9520.362887] dump_stack+0xa4/0xf5 [ 9520.363146] print_address_description+0x78/0x280 [ 9520.363412] kasan_report+0x263/0x390 [ 9520.363650] ? rb_next+0x13/0x90 [ 9520.363873] __asan_load8+0x54/0x90 [ 9520.364102] rb_next+0x13/0x90 [ 9520.364380] btrfs_dump_free_space+0x146/0x160 [btrfs] [ 9520.364697] dump_space_info+0x2cd/0x310 [btrfs] [ 9520.364997] btrfs_reserve_extent+0x1ee/0x1f0 [btrfs] [ 9520.365310] __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs] [ 9520.365646] ? btrfs_update_time+0x180/0x180 [btrfs] [ 9520.365923] ? _raw_spin_unlock+0x27/0x40 [ 9520.366204] ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs] [ 9520.366549] btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs] [ 9520.366880] cache_save_setup+0x42e/0x580 [btrfs] [ 9520.367220] ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs] [ 9520.367518] ? lock_downgrade+0x2f0/0x2f0 [ 9520.367799] ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs] [ 9520.368104] ? kasan_check_read+0x11/0x20 [ 9520.368349] ? do_raw_spin_unlock+0xa8/0x140 [ 9520.368638] btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs] [ 9520.368978] ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs] [ 9520.369282] ? do_raw_spin_unlock+0xa8/0x140 [ 9520.369534] ? _raw_spin_unlock+0x27/0x40 [ 9520.369811] ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs] [ 9520.370137] commit_cowonly_roots+0x4b9/0x610 [btrfs] [ 9520.370560] ? commit_fs_roots+0x350/0x350 [btrfs] [ 9520.370926] ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs] [ 9520.371285] btrfs_commit_transaction+0x5e5/0x10e0 [btrfs] [ 9520.371612] ? btrfs_apply_pending_changes+0x90/0x90 [btrfs] [ 9520.371943] ? start_transaction+0x168/0x6c0 [btrfs] [ 9520.372257] transaction_kthread+0x21c/0x240 [btrfs] [ 9520.372537] kthread+0x1d2/0x1f0 [ 9520.372793] ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs] [ 9520.373090] ? kthread_park+0xb0/0xb0 [ 9520.373329] ret_from_fork+0x3a/0x50 [ 9520.373567] [ 9520.373738] Allocated by task 1804: [ 9520.373974] kasan_kmalloc+0xff/0x180 [ 9520.374208] kasan_slab_alloc+0x11/0x20 [ 9520.374447] kmem_cache_alloc+0xfc/0x2d0 [ 9520.374731] __btrfs_add_free_space+0x40/0x580 [btrfs] [ 9520.375044] unpin_extent_range+0x4f7/0x7a0 [btrfs] [ 9520.375383] btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs] [ 9520.375707] btrfs_commit_transaction+0xb06/0x10e0 [btrfs] [ 9520.376027] btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs] [ 9520.376365] btrfs_check_data_free_space+0x81/0xd0 [btrfs] [ 9520.376689] btrfs_delalloc_reserve_space+0x25/0x80 [btrfs] [ 9520.377018] btrfs_direct_IO+0x42e/0x6d0 [btrfs] [ 9520.377284] generic_file_direct_write+0x11e/0x220 [ 9520.377587] btrfs_file_write_iter+0x472/0xac0 [btrfs] [ 9520.377875] aio_write+0x25c/0x360 [ 9520.378106] io_submit_one+0xaa0/0xdc0 [ 9520.378343] __se_sys_io_submit+0xfa/0x2f0 [ 9520.378589] __x64_sys_io_submit+0x43/0x50 [ 9520.378840] do_syscall_64+0x7d/0x240 [ 9520.379081] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 9520.379387] [ 9520.379557] Freed by task 1802: [ 9520.379782] __kasan_slab_free+0x173/0x260 [ 9520.380028] kasan_slab_free+0xe/0x10 [ 9520.380262] kmem_cache_free+0xc1/0x2c0 [ 9520.380544] btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs] [ 9520.380866] find_free_extent+0xa99/0x17e0 [btrfs] [ 9520.381166] btrfs_reserve_extent+0xd5/0x1f0 [btrfs] [ 9520.381474] btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs] [ 9520.381761] __blockdev_direct_IO+0x10ee/0x58a1 [ 9520.382059] btrfs_direct_IO+0x25a/0x6d0 [btrfs] [ 9520.382321] generic_file_direct_write+0x11e/0x220 [ 9520.382623] btrfs_file_write_iter+0x472/0xac0 [btrfs] [ 9520.382904] aio_write+0x25c/0x360 [ 9520.383172] io_submit_one+0xaa0/0xdc0 [ 9520.383416] __se_sys_io_submit+0xfa/0x2f0 [ 9520.383678] __x64_sys_io_submit+0x43/0x50 [ 9520.383927] do_syscall_64+0x7d/0x240 [ 9520.384165] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 9520.384439] [ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500 which belongs to the cache btrfs_free_space of size 72 [ 9520.385175] The buggy address is located 0 bytes inside of 72-byte region [ffff8800b7ada500, ffff8800b7ada548) [ 9520.385691] The buggy address belongs to the page: [ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0 [ 9520.388030] flags: 0x8100(slab|head) [ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700 [ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000 [ 9520.389169] page dumped because: kasan: bad access detected [ 9520.389473] [ 9520.389658] Memory state around the buggy address: [ 9520.389943] ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 9520.390368] ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc [ 9520.391223] ^ [ 9520.391461] ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 9520.391885] ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 9520.392313] ================================================================== [ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no [ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011 [ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0 [ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G B L 4.19.0-rc8-nbor #555 [ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 9520.395350] RIP: 0010:rb_next+0x3c/0x90 [ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292 [ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c [ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011 [ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc [ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000 [ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000 [ 9520.398555] FS: 0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000 [ 9520.399007] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0 [ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 9520.400400] Call Trace: [ 9520.400648] btrfs_dump_free_space+0x146/0x160 [btrfs] [ 9520.400974] dump_space_info+0x2cd/0x310 [btrfs] [ 9520.401287] btrfs_reserve_extent+0x1ee/0x1f0 [btrfs] [ 9520.401609] __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs] [ 9520.401952] ? btrfs_update_time+0x180/0x180 [btrfs] [ 9520.402232] ? _raw_spin_unlock+0x27/0x40 [ 9520.402522] ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs] [ 9520.402882] btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs] [ 9520.403261] cache_save_setup+0x42e/0x580 [btrfs] [ 9520.403570] ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs] [ 9520.403871] ? lock_downgrade+0x2f0/0x2f0 [ 9520.404161] ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs] [ 9520.404481] ? kasan_check_read+0x11/0x20 [ 9520.404732] ? do_raw_spin_unlock+0xa8/0x140 [ 9520.405026] btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs] [ 9520.405375] ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs] [ 9520.405694] ? do_raw_spin_unlock+0xa8/0x140 [ 9520.405958] ? _raw_spin_unlock+0x27/0x40 [ 9520.406243] ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs] [ 9520.406574] commit_cowonly_roots+0x4b9/0x610 [btrfs] [ 9520.406899] ? commit_fs_roots+0x350/0x350 [btrfs] [ 9520.407253] ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs] [ 9520.407589] btrfs_commit_transaction+0x5e5/0x10e0 [btrfs] [ 9520.407925] ? btrfs_apply_pending_changes+0x90/0x90 [btrfs] [ 9520.408262] ? start_transaction+0x168/0x6c0 [btrfs] [ 9520.408582] transaction_kthread+0x21c/0x240 [btrfs] [ 9520.408870] kthread+0x1d2/0x1f0 [ 9520.409138] ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs] [ 9520.409440] ? kthread_park+0xb0/0xb0 [ 9520.409682] ret_from_fork+0x3a/0x50 [ 9520.410508] Dumping ftrace buffer: [ 9520.410764] (ftrace buffer empty) [ 9520.411007] CR2: 0000000000000011 [ 9520.411297] ---[ end trace 01a0863445cf360a ]--- [ 9520.411568] RIP: 0010:rb_next+0x3c/0x90 [ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292 [ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c [ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011 [ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc [ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000 [ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000 [ 9520.416074] FS: 0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000 [ 9520.416536] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0 [ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 9520.419204] Kernel panic - not syncing: Fatal exception [ 9520.419666] Dumping ftrace buffer: [ 9520.419930] (ftrace buffer empty) [ 9520.420168] Kernel Offset: disabled [ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]--- Fix this by acquiring the respective lock before iterating the rbtree. Reported-by: Nikolay Borisov CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

Btrfs: fix use-after-free during inode eviction

2018-11-13T19:12:58+00:00

commit 421f0922a2cfb0c75acd9746454aaa576c711a65 upstream. At inode.c:evict_inode_truncate_pages(), when we iterate over the inode's extent states, we access an extent state record's "state" field after we unlocked the inode's io tree lock. This can lead to a use-after-free issue because after we unlock the io tree that extent state record might have been freed due to being merged into another adjacent extent state record (a previous inflight bio for a read operation finished in the meanwhile which unlocked a range in the io tree and cause a merge of extent state records, as explained in the comment before the while loop added in commit 6ca0709756710 ("Btrfs: fix hang during inode eviction due to concurrent readahead")). Fix this by keeping a copy of the extent state's flags in a local variable and using it after unlocking the io tree. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201189 Fixes: b9d0b38928e2 ("btrfs: Add handler for invalidate page") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: move the dio_sem higher up the callchain

2018-11-13T19:12:58+00:00

commit c495144bc6962186feae31d687596d2472000e45 upstream. We're getting a lockdep splat because we take the dio_sem under the log_mutex. What we really need is to protect fsync() from logging an extent map for an extent we never waited on higher up, so just guard the whole thing with dio_sem. ====================================================== WARNING: possible circular locking dependency detected 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Not tainted ------------------------------------------------------ aio-dio-invalid/30928 is trying to acquire lock: 0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0 but task is already holding lock: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&ei->dio_sem){++++}: lock_acquire+0xbd/0x220 down_write+0x51/0xb0 btrfs_log_changed_extents+0x80/0xa40 btrfs_log_inode+0xbaf/0x1000 btrfs_log_inode_parent+0x26f/0xa80 btrfs_log_dentry_safe+0x50/0x70 btrfs_sync_file+0x357/0x540 do_fsync+0x38/0x60 __ia32_sys_fdatasync+0x12/0x20 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #4 (&ei->log_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_record_unlink_dir+0x2a/0xa0 btrfs_unlink+0x5a/0xc0 vfs_unlink+0xb1/0x1a0 do_unlinkat+0x264/0x2b0 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #3 (sb_internal#2){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 start_transaction+0x3e6/0x590 btrfs_evict_inode+0x475/0x640 evict+0xbf/0x1b0 btrfs_run_delayed_iputs+0x6c/0x90 cleaner_kthread+0x124/0x1a0 kthread+0x106/0x140 ret_from_fork+0x3a/0x50 -> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_alloc_data_chunk_ondemand+0x197/0x530 btrfs_check_data_free_space+0x4c/0x90 btrfs_delalloc_reserve_space+0x20/0x60 btrfs_page_mkwrite+0x87/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #1 (sb_pagefaults){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 btrfs_page_mkwrite+0x6a/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #0 (&mm->mmap_sem){++++}: __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 down_read+0x48/0xb0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 __blockdev_direct_IO+0x32d/0x1c20 btrfs_direct_IO+0x227/0x400 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 io_submit_one+0x3a9/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 other info that might help us debug this: Chain exists of: &mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->dio_sem); lock(&ei->log_mutex); lock(&ei->dio_sem); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by aio-dio-invalid/30928: #0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 stack backtrace: CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Call Trace: dump_stack+0x7c/0xbb print_circular_bug.isra.37+0x297/0x2a4 check_prev_add.constprop.45+0x781/0x7a0 ? __lock_acquire+0x42e/0x7a0 validate_chain.isra.41+0x7f0/0xb00 __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 ? get_user_pages_unlocked+0x5a/0x1e0 down_read+0x48/0xb0 ? get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 ? __alloc_workqueue_key+0x358/0x490 ? __blockdev_direct_IO+0x14b/0x1c20 __blockdev_direct_IO+0x32d/0x1c20 ? btrfs_run_delalloc_work+0x40/0x40 ? can_nocow_extent+0x490/0x490 ? kvm_clock_read+0x1f/0x30 ? can_nocow_extent+0x490/0x490 ? btrfs_run_delalloc_work+0x40/0x40 btrfs_direct_IO+0x227/0x400 ? btrfs_run_delalloc_work+0x40/0x40 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 ? kvm_clock_read+0x1f/0x30 ? __might_fault+0x3e/0x90 io_submit_one+0x3a9/0x620 ? io_submit_one+0xe5/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: don't run delayed_iputs in commit

2018-11-13T19:12:58+00:00

commit 30928e9baac238a7330085a1c5747f0b5df444b4 upstream. This could result in a really bad case where we do something like evict evict_refill_and_join btrfs_commit_transaction btrfs_run_delayed_iputs evict evict_refill_and_join btrfs_commit_transaction ... forever We have plenty of other places where we run delayed iputs that are much safer, let those do the work. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: fix insert_reserved error handling

2018-11-13T19:12:58+00:00

commit 80ee54bfe8a3850015585ebc84e8d207fcae6831 upstream. We were not handling the reserved byte accounting properly for data references. Metadata was fine, if it errored out the error paths would free the bytes_reserved count and pin the extent, but it even missed one of the error cases. So instead move this handling up into run_one_delayed_ref so we are sure that both cases are properly cleaned up in case of a transaction abort. CC: stable@vger.kernel.org # 4.18+ Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: only free reserved extent if we didn't insert it

2018-11-13T19:12:58+00:00

commit 49940bdd57779c78462da7aa5a8650b2fea8c2ff upstream. When we insert the file extent once the ordered extent completes we free the reserved extent reservation as it'll have been migrated to the bytes_used counter. However if we error out after this step we'll still clear the reserved extent reservation, resulting in a negative accounting of the reserved bytes for the block group and space info. Fix this by only doing the free if we didn't successfully insert a file extent for this extent. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Omar Sandoval Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: don't use ctl->free_space for max_extent_size

2018-11-13T19:12:58+00:00

commit fb5c39d7a887108087de6ff93d3f326b01b4ef41 upstream. max_extent_size is supposed to be the largest contiguous range for the space info, and ctl->free_space is the total free space in the block group. We need to keep track of these separately and _only_ use the max_free_space if we don't have a max_extent_size, as that means our original request was too large to search any of the block groups for and therefore wouldn't have a max_extent_size set. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: set max_extent_size properly

2018-11-13T19:12:57+00:00

commit ad22cf6ea47fa20fbe11ac324a0a15c0a9a4a2a9 upstream. We can't use entry->bytes if our entry is a bitmap entry, we need to use entry->max_extent_size in that case. Fix up all the logic to make this consistent. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: reset max_extent_size properly

2018-11-13T19:12:57+00:00

commit 21a94f7acf0f748599ea552af5d9ee7d7e41c72f upstream. If we use up our block group before allocating a new one we'll easily get a max_extent_size that's set really really low, which will result in a lot of fragmentation. We need to make sure we're resetting the max_extent_size when we add a new chunk or add new space. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

Btrfs: fix deadlock when writing out free space caches

2018-11-13T19:12:57+00:00

commit 5ce555578e0919237fa4bda92b4670e2dd176f85 upstream. When writing out a block group free space cache we can end deadlocking with ourselves on an extent buffer lock resulting in a warning like the following: [245043.379979] WARNING: CPU: 4 PID: 2608 at fs/btrfs/locking.c:251 btrfs_tree_lock+0x1be/0x1d0 [btrfs] [245043.392792] CPU: 4 PID: 2608 Comm: btrfs-transacti Tainted: G W I 4.16.8 #1 [245043.395489] RIP: 0010:btrfs_tree_lock+0x1be/0x1d0 [btrfs] [245043.396791] RSP: 0018:ffffc9000424b840 EFLAGS: 00010246 [245043.398093] RAX: 0000000000000a30 RBX: ffff8807e20a3d20 RCX: 0000000000000001 [245043.399414] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8807e20a3d20 [245043.400732] RBP: 0000000000000001 R08: ffff88041f39a700 R09: ffff880000000000 [245043.402021] R10: 0000000000000040 R11: ffff8807e20a3d20 R12: ffff8807cb220630 [245043.403296] R13: 0000000000000001 R14: ffff8807cb220628 R15: ffff88041fbdf000 [245043.404780] FS: 0000000000000000(0000) GS:ffff88082fc80000(0000) knlGS:0000000000000000 [245043.406050] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [245043.407321] CR2: 00007fffdbdb9f10 CR3: 0000000001c09005 CR4: 00000000000206e0 [245043.408670] Call Trace: [245043.409977] btrfs_search_slot+0x761/0xa60 [btrfs] [245043.411278] btrfs_insert_empty_items+0x62/0xb0 [btrfs] [245043.412572] btrfs_insert_item+0x5b/0xc0 [btrfs] [245043.413922] btrfs_create_pending_block_groups+0xfb/0x1e0 [btrfs] [245043.415216] do_chunk_alloc+0x1e5/0x2a0 [btrfs] [245043.416487] find_free_extent+0xcd0/0xf60 [btrfs] [245043.417813] btrfs_reserve_extent+0x96/0x1e0 [btrfs] [245043.419105] btrfs_alloc_tree_block+0xfb/0x4a0 [btrfs] [245043.420378] __btrfs_cow_block+0x127/0x550 [btrfs] [245043.421652] btrfs_cow_block+0xee/0x190 [btrfs] [245043.422979] btrfs_search_slot+0x227/0xa60 [btrfs] [245043.424279] ? btrfs_update_inode_item+0x59/0x100 [btrfs] [245043.425538] ? iput+0x72/0x1e0 [245043.426798] write_one_cache_group.isra.49+0x20/0x90 [btrfs] [245043.428131] btrfs_start_dirty_block_groups+0x102/0x420 [btrfs] [245043.429419] btrfs_commit_transaction+0x11b/0x880 [btrfs] [245043.430712] ? start_transaction+0x8e/0x410 [btrfs] [245043.432006] transaction_kthread+0x184/0x1a0 [btrfs] [245043.433341] kthread+0xf0/0x130 [245043.434628] ? btrfs_cleanup_transaction+0x4e0/0x4e0 [btrfs] [245043.435928] ? kthread_create_worker_on_cpu+0x40/0x40 [245043.437236] ret_from_fork+0x1f/0x30 [245043.441054] ---[ end trace 15abaa2aaf36827f ]--- This is because at write_one_cache_group() when we are COWing a leaf from the extent tree we end up allocating a new block group (chunk) and, because we have hit a threshold on the number of bytes reserved for system chunks, we attempt to finalize the creation of new block groups from the current transaction, by calling btrfs_create_pending_block_groups(). However here we also need to modify the extent tree in order to insert a block group item, and if the location for this new block group item happens to be in the same leaf that we were COWing earlier, we deadlock since btrfs_search_slot() tries to write lock the extent buffer that we locked before at write_one_cache_group(). We have already hit similar cases in the past and commit d9a0540a79f8 ("Btrfs: fix deadlock when finalizing block group creation") fixed some of those cases by delaying the creation of pending block groups at the known specific spots that could lead to a deadlock. This change reworks that commit to be more generic so that we don't have to add similar logic to every possible path that can lead to a deadlock. This is done by making __btrfs_cow_block() disallowing the creation of new block groups (setting the transaction's can_flush_pending_bgs to false) before it attempts to allocate a new extent buffer for either the extent, chunk or device trees, since those are the trees that pending block creation modifies. Once the new extent buffer is allocated, it allows creation of pending block groups to happen again. This change depends on a recent patch from Josef which is not yet in Linus' tree, named "btrfs: make sure we create all new block groups" in order to avoid occasional warnings at btrfs_trans_release_chunk_metadata(). Fixes: d9a0540a79f8 ("Btrfs: fix deadlock when finalizing block group creation") CC: stable@vger.kernel.org # 4.4+ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199753 Link: https://lore.kernel.org/linux-btrfs/CAJtFHUTHna09ST-_EEiyWmDH6gAqS6wa=zMNMBsifj8ABu99cw@mail.gmail.com/ Reported-by: E V Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman