- 06 11月, 2020 1 次提交
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由 Pavel Begunkov 提交于
If there is a long-standing request of one task locking up execution of deferred requests, and the defer list contains requests of another task (all files-less), then a potential execution of __io_uring_task_cancel() by that another task will sleep until that first long-standing request completion, and that may take long. E.g. tsk1: req1/read(empty_pipe) -> tsk2: req(DRAIN) Then __io_uring_task_cancel(tsk2) waits for req1 completion. It seems we even can manufacture a complicated case with many tasks sharing many rings that can lock them forever. Cancel deferred requests for __io_uring_task_cancel() as well. Signed-off-by: NPavel Begunkov <asml.silence@gmail.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 05 11月, 2020 5 次提交
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由 Pavel Begunkov 提交于
Current io_match_files() check in io_cqring_overflow_flush() is useless because requests drop ->files before going to the overflow list, however linked to it request do not, and we don't check them. Signed-off-by: NPavel Begunkov <asml.silence@gmail.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Jens Axboe 提交于
We can't bundle this into one operation, as the identity may not have originated from the tctx to begin with. Drop one ref for each of them separately, if they don't match the static assignment. If we don't, then if the identity is a lookup from registered credentials, we could be freeing that identity as we're dropping a reference assuming it came from the tctx. syzbot reports this as a use-after-free, as the identity is still referencable from idr lookup: ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline] BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline] BUG: KASAN: use-after-free in io_init_req fs/io_uring.c:6700 [inline] BUG: KASAN: use-after-free in io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774 Write of size 4 at addr ffff888011e08e48 by task syz-executor165/8487 CPU: 1 PID: 8487 Comm: syz-executor165 Not tainted 5.10.0-rc1-next-20201102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] io_init_req fs/io_uring.c:6700 [inline] io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440e19 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 0f fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff644ff178 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000440e19 RDX: 0000000000000000 RSI: 000000000000450c RDI: 0000000000000003 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000022b4850 R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 8487: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 kmalloc include/linux/slab.h:552 [inline] io_register_personality fs/io_uring.c:9638 [inline] __io_uring_register fs/io_uring.c:9874 [inline] __do_sys_io_uring_register+0x10f0/0x40a0 fs/io_uring.c:9924 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 8487: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kfree+0xdb/0x360 mm/slub.c:4122 io_identity_cow fs/io_uring.c:1380 [inline] io_prep_async_work+0x903/0xbc0 fs/io_uring.c:1492 io_prep_async_link fs/io_uring.c:1505 [inline] io_req_defer fs/io_uring.c:5999 [inline] io_queue_sqe+0x212/0xed0 fs/io_uring.c:6448 io_submit_sqe fs/io_uring.c:6542 [inline] io_submit_sqes+0x14f6/0x25f0 fs/io_uring.c:6784 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888011e08e00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 72 bytes inside of 96-byte region [ffff888011e08e00, ffff888011e08e60) The buggy address belongs to the page: page:00000000a7104751 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e08 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea00004f8540 0000001f00000002 ffff888010041780 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888011e08d00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888011e08d80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc > ffff888011e08e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888011e08e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888011e08f00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ================================================================== Reported-by: syzbot+625ce3bb7835b63f7f3d@syzkaller.appspotmail.com Fixes: 1e6fa521 ("io_uring: COW io_identity on mismatch") Signed-off-by: NJens Axboe <axboe@kernel.dk> -
由 Jens Axboe 提交于
Ensure we get a valid view of the task mm, by using task_lock() when attempting to grab the original task mm. Reported-by: syzbot+b57abf7ee60829090495@syzkaller.appspotmail.com Fixes: 2aede0e4 ("io_uring: stash ctx task reference for SQPOLL") Signed-off-by: NJens Axboe <axboe@kernel.dk>
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由 Jens Axboe 提交于
Track if a given task io_uring context contains SQPOLL instances, so we can iterate those for cancelation (and request counts). This ensures that we properly wait on SQPOLL contexts, and find everything that needs canceling. Signed-off-by: NJens Axboe <axboe@kernel.dk> -
由 Jens Axboe 提交于
This can't currently happen, but will be possible shortly. Handle missing files just like we do not being able to grab a needed mm, and mark the request as needing cancelation. Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 30 10月, 2020 2 次提交
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由 Greg Kroah-Hartman 提交于
No one checks the return value of debugfs_create_devm_seqfile(), as it's not needed, so make the return value void, so that no one tries to do so in the future. Link: https://lore.kernel.org/r/20201023131037.2500765-1-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Gustavo A. R. Silva 提交于
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arraysSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
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- 29 10月, 2020 16 次提交
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由 David Howells 提交于
The dirty region bounds stored in page->private on an afs page are 15 bits on a 32-bit box and can, at most, represent a range of up to 32K within a 32K page with a resolution of 1 byte. This is a problem for powerpc32 with 64K pages enabled. Further, transparent huge pages may get up to 2M, which will be a problem for the afs filesystem on all 32-bit arches in the future. Fix this by decreasing the resolution. For the moment, a 64K page will have a resolution determined from PAGE_SIZE. In the future, the page will need to be passed in to the helper functions so that the page size can be assessed and the resolution determined dynamically. Note that this might not be the ideal way to handle this, since it may allow some leakage of undirtied zero bytes to the server's copy in the case of a 3rd-party conflict. Fixing that would require a separately allocated record and is a more complicated fix. Fixes: 4343d008 ("afs: Get rid of the afs_writeback record") Reported-by: Nkernel test robot <lkp@intel.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
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由 David Howells 提交于
Fix afs_invalidatepage() to adjust the dirty region recorded in page->private when truncating a page. If the dirty region is entirely removed, then the private data is cleared and the page dirty state is cleared. Without this, if the page is truncated and then expanded again by truncate, zeros from the expanded, but no-longer dirty region may get written back to the server if the page gets laundered due to a conflicting 3rd-party write. It mustn't, however, shorten the dirty region of the page if that page is still mmapped and has been marked dirty by afs_page_mkwrite(), so a flag is stored in page->private to record this. Fixes: 4343d008 ("afs: Get rid of the afs_writeback record") Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
Currently, page->private on an afs page is used to store the range of dirtied data within the page, where the range includes the lower bound, but excludes the upper bound (e.g. 0-1 is a range covering a single byte). This, however, requires a superfluous bit for the last-byte bound so that on a 4KiB page, it can say 0-4096 to indicate the whole page, the idea being that having both numbers the same would indicate an empty range. This is unnecessary as the PG_private bit is clear if it's an empty range (as is PG_dirty). Alter the way the dirty range is encoded in page->private such that the upper bound is reduced by 1 (e.g. 0-0 is then specified the same single byte range mentioned above). Applying this to both bounds frees up two bits, one of which can be used in a future commit. This allows the afs filesystem to be compiled on ppc32 with 64K pages; without this, the following warnings are seen: ../fs/afs/internal.h: In function 'afs_page_dirty_to': ../fs/afs/internal.h:881:15: warning: right shift count >= width of type [-Wshift-count-overflow] 881 | return (priv >> __AFS_PAGE_PRIV_SHIFT) & __AFS_PAGE_PRIV_MASK; | ^~ ../fs/afs/internal.h: In function 'afs_page_dirty': ../fs/afs/internal.h:886:28: warning: left shift count >= width of type [-Wshift-count-overflow] 886 | return ((unsigned long)to << __AFS_PAGE_PRIV_SHIFT) | from; | ^~ Fixes: 4343d008 ("afs: Get rid of the afs_writeback record") Signed-off-by: NDavid Howells <dhowells@redhat.com> -
由 David Howells 提交于
The afs filesystem uses page->private to store the dirty range within a page such that in the event of a conflicting 3rd-party write to the server, we write back just the bits that got changed locally. However, there are a couple of problems with this: (1) I need a bit to note if the page might be mapped so that partial invalidation doesn't shrink the range. (2) There aren't necessarily sufficient bits to store the entire range of data altered (say it's a 32-bit system with 64KiB pages or transparent huge pages are in use). So wrap the accesses in inline functions so that future commits can change how this works. Also move them out of the tracing header into the in-directory header. There's not really any need for them to be in the tracing header. Signed-off-by: NDavid Howells <dhowells@redhat.com> -
由 David Howells 提交于
In afs, page->private is set to indicate the dirty region of a page. This is done in afs_write_begin(), but that can't take account of whether the copy into the page actually worked. Fix this by moving the change of page->private into afs_write_end(). Fixes: 4343d008 ("afs: Get rid of the afs_writeback record") Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
Fix the leak of the target page in afs_write_begin() when it fails. Fixes: 15b4650e ("afs: convert to new aops") Signed-off-by: NDavid Howells <dhowells@redhat.com> cc: Nick Piggin <npiggin@gmail.com>
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由 David Howells 提交于
Fix afs to take a ref on a page when it sets PG_private on it and to drop the ref when removing the flag. Note that in afs_write_begin(), a lot of the time, PG_private is already set on a page to which we're going to add some data. In such a case, we leave the bit set and mustn't increment the page count. As suggested by Matthew Wilcox, use attach/detach_page_private() where possible. Fixes: 31143d5d ("AFS: implement basic file write support") Reported-by: NMatthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: NDavid Howells <dhowells@redhat.com> Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
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由 Theodore Ts'o 提交于
Signed-off-by: NTheodore Ts'o <tytso@mit.edu> -
由 Daniel Rosenberg 提交于
This switches ext4 over to the generic support provided in libfs. Since casefolded dentries behave the same in ext4 and f2fs, we decrease the maintenance burden by unifying them, and any optimizations will immediately apply to both. Signed-off-by: NDaniel Rosenberg <drosen@google.com> Reviewed-by: NEric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20201028050820.1636571-1-drosen@google.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 yangerkun 提交于
ext4_ext_search_right() will read more extent blocks and call put_bh after we get the information we need. However, ret_ex will break this and may cause use-after-free once pagecache has been freed. Fix it by copying the extent structure if needed. Signed-off-by: Nyangerkun <yangerkun@huawei.com> Link: https://lore.kernel.org/r/20201028055617.2569255-1-yangerkun@huawei.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
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由 Harshad Shirwadkar 提交于
With this fix, fast commit recovery code uses IS_ERR() for path returned by ext4_find_extent. Fixes: 8016e29f ("ext4: fast commit recovery path") Reported-by: NDan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201027204342.2794949-1-harshadshirwadkar@gmail.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Jan Kara 提交于
Commit afb585a9 "ext4: data=journal: write-protect pages on j_submit_inode_data_buffers()") added calls ext4_jbd2_inode_add_write() to track inode ranges whose mappings need to get write-protected during transaction commits. However the added calls use wrong start of a range (0 instead of page offset) and so write protection is not necessarily effective. Use correct range start to fix the problem. Fixes: afb585a9 ("ext4: data=journal: write-protect pages on j_submit_inode_data_buffers()") Signed-off-by: NJan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20201027132751.29858-1-jack@suse.czSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Harshad Shirwadkar 提交于
Ext4's fast commit related transient states should use sb->s_mount_flags instead of persistent sb->s_mount_state. Fixes: 8016e29f ("ext4: fast commit recovery path") Signed-off-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201027044915.2553163-3-harshadshirwadkar@gmail.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Harshad Shirwadkar 提交于
This patch reserves a field in the jbd2 superblock for number of fast commit blocks. When this value is non-zero, Ext4 uses this field to set the number of fast commit blocks. Fixes: 6866d7b3 ("ext4/jbd2: add fast commit initialization") Signed-off-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201027044915.2553163-2-harshadshirwadkar@gmail.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Andrea Righi 提交于
ext4_inode_datasync_dirty() needs to return 'true' if the inode is dirty, 'false' otherwise, but the logic seems to be incorrectly changed by commit aa75f4d3 ("ext4: main fast-commit commit path"). This introduces a problem with swap files that are always failing to be activated, showing this error in dmesg: [ 34.406479] swapon: file is not committed Simple test case to reproduce the problem: # fallocate -l 8G swapfile # chmod 0600 swapfile # mkswap swapfile # swapon swapfile Fix the logic to return the proper state of the inode. Link: https://lore.kernel.org/lkml/20201024131333.GA32124@xps-13-7390 Fixes: 8016e29f ("ext4: fast commit recovery path") Signed-off-by: NAndrea Righi <andrea.righi@canonical.com> Signed-off-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201027044915.2553163-1-harshadshirwadkar@gmail.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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由 Harshad Shirwadkar 提交于
Fixed double locking of sbi->s_fc_lock in the above function as reported by kernel-test-robot. Signed-off-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201023161339.1449437-1-harshadshirwadkar@gmail.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
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- 28 10月, 2020 4 次提交
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由 David Howells 提交于
Fix afs_launder_page() to not clear PG_writeback on the page it is laundering as the flag isn't set in this case. Fixes: 4343d008 ("afs: Get rid of the afs_writeback record") Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 Dan Carpenter 提交于
The "op" pointer is freed earlier when we call afs_put_operation(). Fixes: e49c7b2f ("afs: Build an abstraction around an "operation" concept") Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> cc: Colin Ian King <colin.king@canonical.com>
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由 David Howells 提交于
The patch dca54a7b: "afs: Add tracing for cell refcount and active user count" from Oct 13, 2020, leads to the following Smatch complaint: fs/afs/cell.c:596 afs_unuse_cell() warn: variable dereferenced before check 'cell' (see line 592) Fix this by moving the retrieval of the cell debug ID to after the check of the validity of the cell pointer. Reported-by: NDan Carpenter <dan.carpenter@oracle.com> Fixes: dca54a7b ("afs: Add tracing for cell refcount and active user count") Signed-off-by: NDavid Howells <dhowells@redhat.com> cc: Dan Carpenter <dan.carpenter@oracle.com>
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由 David Howells 提交于
The prevention of splice-write without explicit ops made the copy_file_write() syscall to an afs file (as done by the generic/112 xfstest) fail with EINVAL. Fix by using iter_file_splice_write() for afs. Fixes: 36e2c742 ("fs: don't allow splice read/write without explicit ops") Signed-off-by: NDavid Howells <dhowells@redhat.com> Reviewed-by: NChristoph Hellwig <hch@lst.de>
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- 27 10月, 2020 3 次提交
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由 Davidlohr Bueso 提交于
By doing so we can associate the sequence counter to the chunk_mutex for lockdep purposes (compiled-out otherwise), the mutex is otherwise used on the write side. Also avoid explicitly disabling preemption around the write region as it will now be done automatically by the seqcount machinery based on the lock type. Signed-off-by: NDavidlohr Bueso <dbueso@suse.de> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Johannes Thumshirn 提交于
Since we switched to the iomap infrastructure in b5ff9f1a96e8f ("btrfs: switch to iomap for direct IO") we're calling generic_file_buffered_read() directly and not via generic_file_read_iter() anymore. If the read could read everything there is no need to bother calling generic_file_buffered_read(), like it is handled in generic_file_read_iter(). If we call generic_file_buffered_read() in this case we can hit a situation where we do an invalid readahead and cause this UBSAN splat in fstest generic/091: run fstests generic/091 at 2020-10-21 10:52:32 ================================================================================ UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 shift exponent 64 is too large for 64-bit type 'long unsigned int' CPU: 0 PID: 656 Comm: fsx Not tainted 5.9.0-rc7+ #821 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 dump_stack+0x57/0x70 lib/dump_stack.c:118 ubsan_epilogue+0x5/0x40 lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0x61/0xe9 lib/ubsan.c:395 __roundup_pow_of_two ./include/linux/log2.h:57 get_init_ra_size mm/readahead.c:318 ondemand_readahead.cold+0x16/0x2c mm/readahead.c:530 generic_file_buffered_read+0x3ac/0x840 mm/filemap.c:2199 call_read_iter ./include/linux/fs.h:1876 new_sync_read+0x102/0x180 fs/read_write.c:415 vfs_read+0x11c/0x1a0 fs/read_write.c:481 ksys_read+0x4f/0xc0 fs/read_write.c:615 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 arch/x86/entry/entry_64.S:118 RIP: 0033:0x7fe87fee992e RSP: 002b:00007ffe01605278 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000004f000 RCX: 00007fe87fee992e RDX: 0000000000004000 RSI: 0000000001677000 RDI: 0000000000000003 RBP: 000000000004f000 R08: 0000000000004000 R09: 000000000004f000 R10: 0000000000053000 R11: 0000000000000246 R12: 0000000000004000 R13: 0000000000000000 R14: 000000000007a120 R15: 0000000000000000 ================================================================================ BTRFS info (device nullb0): has skinny extents BTRFS info (device nullb0): ZONED mode enabled, zone size 268435456 B BTRFS info (device nullb0): enabling ssd optimizations Fixes: f85781fb ("btrfs: switch to iomap for direct IO") Reviewed-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Matthew Wilcox (Oracle) 提交于
If ->readpage returns an error, it has already unlocked the page. Fixes: 5e929b33 ("CacheFiles: Handle truncate unlocking the page we're reading") Cc: stable@vger.kernel.org Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 10月, 2020 9 次提交
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由 Josef Bacik 提交于
I got the following lockdep splat with tree locks converted to rwsem patches on btrfs/104: ====================================================== WARNING: possible circular locking dependency detected 5.9.0+ #102 Not tainted ------------------------------------------------------ btrfs-cleaner/903 is trying to acquire lock: ffff8e7fab6ffe30 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x32/0x170 but task is already holding lock: ffff8e7fab628a88 (&fs_info->commit_root_sem){++++}-{3:3}, at: btrfs_find_all_roots+0x41/0x80 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&fs_info->commit_root_sem){++++}-{3:3}: down_read+0x40/0x130 caching_thread+0x53/0x5a0 btrfs_work_helper+0xfa/0x520 process_one_work+0x238/0x540 worker_thread+0x55/0x3c0 kthread+0x13a/0x150 ret_from_fork+0x1f/0x30 -> #2 (&caching_ctl->mutex){+.+.}-{3:3}: __mutex_lock+0x7e/0x7b0 btrfs_cache_block_group+0x1e0/0x510 find_free_extent+0xb6e/0x12f0 btrfs_reserve_extent+0xb3/0x1b0 btrfs_alloc_tree_block+0xb1/0x330 alloc_tree_block_no_bg_flush+0x4f/0x60 __btrfs_cow_block+0x11d/0x580 btrfs_cow_block+0x10c/0x220 commit_cowonly_roots+0x47/0x2e0 btrfs_commit_transaction+0x595/0xbd0 sync_filesystem+0x74/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x36/0xa0 cleanup_mnt+0x12d/0x190 task_work_run+0x5c/0xa0 exit_to_user_mode_prepare+0x1df/0x200 syscall_exit_to_user_mode+0x54/0x280 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #1 (&space_info->groups_sem){++++}-{3:3}: down_read+0x40/0x130 find_free_extent+0x2ed/0x12f0 btrfs_reserve_extent+0xb3/0x1b0 btrfs_alloc_tree_block+0xb1/0x330 alloc_tree_block_no_bg_flush+0x4f/0x60 __btrfs_cow_block+0x11d/0x580 btrfs_cow_block+0x10c/0x220 commit_cowonly_roots+0x47/0x2e0 btrfs_commit_transaction+0x595/0xbd0 sync_filesystem+0x74/0x90 generic_shutdown_super+0x22/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 deactivate_locked_super+0x36/0xa0 cleanup_mnt+0x12d/0x190 task_work_run+0x5c/0xa0 exit_to_user_mode_prepare+0x1df/0x200 syscall_exit_to_user_mode+0x54/0x280 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (btrfs-root-00){++++}-{3:3}: __lock_acquire+0x1167/0x2150 lock_acquire+0xb9/0x3d0 down_read_nested+0x43/0x130 __btrfs_tree_read_lock+0x32/0x170 __btrfs_read_lock_root_node+0x3a/0x50 btrfs_search_slot+0x614/0x9d0 btrfs_find_root+0x35/0x1b0 btrfs_read_tree_root+0x61/0x120 btrfs_get_root_ref+0x14b/0x600 find_parent_nodes+0x3e6/0x1b30 btrfs_find_all_roots_safe+0xb4/0x130 btrfs_find_all_roots+0x60/0x80 btrfs_qgroup_trace_extent_post+0x27/0x40 btrfs_add_delayed_data_ref+0x3fd/0x460 btrfs_free_extent+0x42/0x100 __btrfs_mod_ref+0x1d7/0x2f0 walk_up_proc+0x11c/0x400 walk_up_tree+0xf0/0x180 btrfs_drop_snapshot+0x1c7/0x780 btrfs_clean_one_deleted_snapshot+0xfb/0x110 cleaner_kthread+0xd4/0x140 kthread+0x13a/0x150 ret_from_fork+0x1f/0x30 other info that might help us debug this: Chain exists of: btrfs-root-00 --> &caching_ctl->mutex --> &fs_info->commit_root_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->commit_root_sem); lock(&caching_ctl->mutex); lock(&fs_info->commit_root_sem); lock(btrfs-root-00); *** DEADLOCK *** 3 locks held by btrfs-cleaner/903: #0: ffff8e7fab628838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: cleaner_kthread+0x6e/0x140 #1: ffff8e7faadac640 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x40b/0x5c0 #2: ffff8e7fab628a88 (&fs_info->commit_root_sem){++++}-{3:3}, at: btrfs_find_all_roots+0x41/0x80 stack backtrace: CPU: 0 PID: 903 Comm: btrfs-cleaner Not tainted 5.9.0+ #102 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x8b/0xb0 check_noncircular+0xcf/0xf0 __lock_acquire+0x1167/0x2150 ? __bfs+0x42/0x210 lock_acquire+0xb9/0x3d0 ? __btrfs_tree_read_lock+0x32/0x170 down_read_nested+0x43/0x130 ? __btrfs_tree_read_lock+0x32/0x170 __btrfs_tree_read_lock+0x32/0x170 __btrfs_read_lock_root_node+0x3a/0x50 btrfs_search_slot+0x614/0x9d0 ? find_held_lock+0x2b/0x80 btrfs_find_root+0x35/0x1b0 ? do_raw_spin_unlock+0x4b/0xa0 btrfs_read_tree_root+0x61/0x120 btrfs_get_root_ref+0x14b/0x600 find_parent_nodes+0x3e6/0x1b30 btrfs_find_all_roots_safe+0xb4/0x130 btrfs_find_all_roots+0x60/0x80 btrfs_qgroup_trace_extent_post+0x27/0x40 btrfs_add_delayed_data_ref+0x3fd/0x460 btrfs_free_extent+0x42/0x100 __btrfs_mod_ref+0x1d7/0x2f0 walk_up_proc+0x11c/0x400 walk_up_tree+0xf0/0x180 btrfs_drop_snapshot+0x1c7/0x780 ? btrfs_clean_one_deleted_snapshot+0x73/0x110 btrfs_clean_one_deleted_snapshot+0xfb/0x110 cleaner_kthread+0xd4/0x140 ? btrfs_alloc_root+0x50/0x50 kthread+0x13a/0x150 ? kthread_create_worker_on_cpu+0x40/0x40 ret_from_fork+0x1f/0x30 BTRFS info (device sdb): disk space caching is enabled BTRFS info (device sdb): has skinny extents This happens because qgroups does a backref lookup when we create a delayed ref. From here it may have to look up a root from an indirect ref, which does a normal lookup on the tree_root, which takes the read lock on the tree_root nodes. To fix this we need to add a variant for looking up roots that searches the commit root of the tree_root. Then when we do the backref search using the commit root we are sure to not take any locks on the tree_root nodes. This gets rid of the lockdep splat when running btrfs/104. Reviewed-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Josef Bacik 提交于
When enabling qgroups we walk the tree_root and then add a qgroup item for every root that we have. This creates a lock dependency on the tree_root and qgroup_root, which results in the following lockdep splat (with tree locks using rwsem), eg. in tests btrfs/017 or btrfs/022: ====================================================== WARNING: possible circular locking dependency detected 5.9.0-default+ #1299 Not tainted ------------------------------------------------------ btrfs/24552 is trying to acquire lock: ffff9142dfc5f630 (btrfs-quota-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] but task is already holding lock: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-root-00){++++}-{3:3}: __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 down_read_nested+0x46/0x130 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_item+0x6e/0x140 [btrfs] btrfs_create_tree+0x1cb/0x240 [btrfs] btrfs_quota_enable+0xcd/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (btrfs-quota-00){++++}-{3:3}: check_prev_add+0x91/0xc30 validate_chain+0x491/0x750 __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 down_read_nested+0x46/0x130 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_empty_items+0x58/0xa0 [btrfs] add_qgroup_item.part.0+0x72/0x210 [btrfs] btrfs_quota_enable+0x3bb/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(btrfs-quota-00); lock(btrfs-root-00); lock(btrfs-quota-00); *** DEADLOCK *** 5 locks held by btrfs/24552: #0: ffff9142df431478 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0xa0 #1: ffff9142f9b10cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl_quota_ctl+0x7b/0xe0 [btrfs] #2: ffff9142f9b11a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0x790 [btrfs] #3: ffff9142df431698 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x406/0x510 [btrfs] #4: ffff9142dfc5d0b0 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] stack backtrace: CPU: 1 PID: 24552 Comm: btrfs Not tainted 5.9.0-default+ #1299 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0x77/0x97 check_noncircular+0xf3/0x110 check_prev_add+0x91/0xc30 validate_chain+0x491/0x750 __lock_acquire+0x3fb/0x730 lock_acquire.part.0+0x6a/0x130 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] ? lock_acquire+0xc4/0x140 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] down_read_nested+0x46/0x130 ? __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] ? btrfs_root_node+0xd9/0x200 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot_get_root+0x11d/0x290 [btrfs] btrfs_search_slot+0xc3/0x9f0 [btrfs] btrfs_insert_empty_items+0x58/0xa0 [btrfs] add_qgroup_item.part.0+0x72/0x210 [btrfs] btrfs_quota_enable+0x3bb/0x790 [btrfs] btrfs_ioctl_quota_ctl+0xc9/0xe0 [btrfs] __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by dropping the path whenever we find a root item, add the qgroup item, and then re-lookup the root item we found and continue processing roots. Reported-by: NDavid Sterba <dsterba@suse.com> Reviewed-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NJosef Bacik <josef@toxicpanda.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Filipe Manana 提交于
Very sporadically I had test case btrfs/069 from fstests hanging (for years, it is not a recent regression), with the following traces in dmesg/syslog: [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0 [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds. [162513.514318] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.514747] task:btrfs-transacti state:D stack: 0 pid:1356167 ppid: 2 flags:0x00004000 [162513.514751] Call Trace: [162513.514761] __schedule+0x5ce/0xd00 [162513.514765] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.514771] schedule+0x46/0xf0 [162513.514844] wait_current_trans+0xde/0x140 [btrfs] [162513.514850] ? finish_wait+0x90/0x90 [162513.514864] start_transaction+0x37c/0x5f0 [btrfs] [162513.514879] transaction_kthread+0xa4/0x170 [btrfs] [162513.514891] ? btrfs_cleanup_transaction+0x660/0x660 [btrfs] [162513.514894] kthread+0x153/0x170 [162513.514897] ? kthread_stop+0x2c0/0x2c0 [162513.514902] ret_from_fork+0x22/0x30 [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds. [162513.515192] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.515680] task:fsstress state:D stack: 0 pid:1356184 ppid:1356177 flags:0x00004000 [162513.515682] Call Trace: [162513.515688] __schedule+0x5ce/0xd00 [162513.515691] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.515697] schedule+0x46/0xf0 [162513.515712] wait_current_trans+0xde/0x140 [btrfs] [162513.515716] ? finish_wait+0x90/0x90 [162513.515729] start_transaction+0x37c/0x5f0 [btrfs] [162513.515743] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.515753] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.515758] ? __ia32_sys_fdatasync+0x20/0x20 [162513.515761] iterate_supers+0x87/0xf0 [162513.515765] ksys_sync+0x60/0xb0 [162513.515768] __do_sys_sync+0xa/0x10 [162513.515771] do_syscall_64+0x33/0x80 [162513.515774] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.515781] RIP: 0033:0x7f5238f50bd7 [162513.515782] Code: Bad RIP value. [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0 [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds. [162513.516064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.516617] task:fsstress state:D stack: 0 pid:1356185 ppid:1356177 flags:0x00000000 [162513.516620] Call Trace: [162513.516625] __schedule+0x5ce/0xd00 [162513.516628] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.516634] schedule+0x46/0xf0 [162513.516647] wait_current_trans+0xde/0x140 [btrfs] [162513.516650] ? finish_wait+0x90/0x90 [162513.516662] start_transaction+0x4d7/0x5f0 [btrfs] [162513.516679] btrfs_setxattr_trans+0x3c/0x100 [btrfs] [162513.516686] __vfs_setxattr+0x66/0x80 [162513.516691] __vfs_setxattr_noperm+0x70/0x200 [162513.516697] vfs_setxattr+0x6b/0x120 [162513.516703] setxattr+0x125/0x240 [162513.516709] ? lock_acquire+0xb1/0x480 [162513.516712] ? mnt_want_write+0x20/0x50 [162513.516721] ? rcu_read_lock_any_held+0x8e/0xb0 [162513.516723] ? preempt_count_add+0x49/0xa0 [162513.516725] ? __sb_start_write+0x19b/0x290 [162513.516727] ? preempt_count_add+0x49/0xa0 [162513.516732] path_setxattr+0xba/0xd0 [162513.516739] __x64_sys_setxattr+0x27/0x30 [162513.516741] do_syscall_64+0x33/0x80 [162513.516743] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.516745] RIP: 0033:0x7f5238f56d5a [162513.516746] Code: Bad RIP value. [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470 [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700 [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004 [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0 [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds. [162513.517064] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.517763] task:fsstress state:D stack: 0 pid:1356196 ppid:1356177 flags:0x00004000 [162513.517780] Call Trace: [162513.517786] __schedule+0x5ce/0xd00 [162513.517789] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.517796] schedule+0x46/0xf0 [162513.517810] wait_current_trans+0xde/0x140 [btrfs] [162513.517814] ? finish_wait+0x90/0x90 [162513.517829] start_transaction+0x37c/0x5f0 [btrfs] [162513.517845] btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs] [162513.517857] btrfs_sync_fs+0x61/0x1c0 [btrfs] [162513.517862] ? __ia32_sys_fdatasync+0x20/0x20 [162513.517865] iterate_supers+0x87/0xf0 [162513.517869] ksys_sync+0x60/0xb0 [162513.517872] __do_sys_sync+0xa/0x10 [162513.517875] do_syscall_64+0x33/0x80 [162513.517878] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.517881] RIP: 0033:0x7f5238f50bd7 [162513.517883] Code: Bad RIP value. [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2 [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7 [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053 [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0 [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053 [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340 [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds. [162513.518298] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.519157] task:fsstress state:D stack: 0 pid:1356197 ppid:1356177 flags:0x00000000 [162513.519160] Call Trace: [162513.519165] __schedule+0x5ce/0xd00 [162513.519168] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.519174] schedule+0x46/0xf0 [162513.519190] wait_current_trans+0xde/0x140 [btrfs] [162513.519193] ? finish_wait+0x90/0x90 [162513.519206] start_transaction+0x4d7/0x5f0 [btrfs] [162513.519222] btrfs_create+0x57/0x200 [btrfs] [162513.519230] lookup_open+0x522/0x650 [162513.519246] path_openat+0x2b8/0xa50 [162513.519270] do_filp_open+0x91/0x100 [162513.519275] ? find_held_lock+0x32/0x90 [162513.519280] ? lock_acquired+0x33b/0x470 [162513.519285] ? do_raw_spin_unlock+0x4b/0xc0 [162513.519287] ? _raw_spin_unlock+0x29/0x40 [162513.519295] do_sys_openat2+0x20d/0x2d0 [162513.519300] do_sys_open+0x44/0x80 [162513.519304] do_syscall_64+0x33/0x80 [162513.519307] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.519309] RIP: 0033:0x7f5238f4a903 [162513.519310] Code: Bad RIP value. [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903 [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470 [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002 [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013 [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620 [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds. [162513.519727] Not tainted 5.9.0-rc6-btrfs-next-69 #1 [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [162513.520508] task:btrfs state:D stack: 0 pid:1356211 ppid:1356178 flags:0x00004002 [162513.520511] Call Trace: [162513.520516] __schedule+0x5ce/0xd00 [162513.520519] ? _raw_spin_unlock_irqrestore+0x3c/0x60 [162513.520525] schedule+0x46/0xf0 [162513.520544] btrfs_scrub_pause+0x11f/0x180 [btrfs] [162513.520548] ? finish_wait+0x90/0x90 [162513.520562] btrfs_commit_transaction+0x45a/0xc30 [btrfs] [162513.520574] ? start_transaction+0xe0/0x5f0 [btrfs] [162513.520596] btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs] [162513.520619] btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs] [162513.520639] btrfs_ioctl+0x2a25/0x36f0 [btrfs] [162513.520643] ? do_sigaction+0xf3/0x240 [162513.520645] ? find_held_lock+0x32/0x90 [162513.520648] ? do_sigaction+0xf3/0x240 [162513.520651] ? lock_acquired+0x33b/0x470 [162513.520655] ? _raw_spin_unlock_irq+0x24/0x50 [162513.520657] ? lockdep_hardirqs_on+0x7d/0x100 [162513.520660] ? _raw_spin_unlock_irq+0x35/0x50 [162513.520662] ? do_sigaction+0xf3/0x240 [162513.520671] ? __x64_sys_ioctl+0x83/0xb0 [162513.520672] __x64_sys_ioctl+0x83/0xb0 [162513.520677] do_syscall_64+0x33/0x80 [162513.520679] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [162513.520681] RIP: 0033:0x7fc3cd307d87 [162513.520682] Code: Bad RIP value. [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87 [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003 [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003 [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001 [162513.520703] Showing all locks held in the system: [162513.520712] 1 lock held by khungtaskd/54: [162513.520713] #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197 [162513.520728] 1 lock held by in:imklog/596: [162513.520729] #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60 [162513.520782] 1 lock held by btrfs-transacti/1356167: [162513.520784] #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs] [162513.520798] 1 lock held by btrfs/1356190: [162513.520800] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60 [162513.520805] 1 lock held by fsstress/1356184: [162513.520806] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520811] 3 locks held by fsstress/1356185: [162513.520812] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520815] #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120 [162513.520820] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520833] 1 lock held by fsstress/1356196: [162513.520834] #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0 [162513.520838] 3 locks held by fsstress/1356197: [162513.520839] #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50 [162513.520843] #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50 [162513.520846] #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] [162513.520858] 2 locks held by btrfs/1356211: [162513.520859] #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs] [162513.520877] #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs] This was weird because the stack traces show that a transaction commit, triggered by a device replace operation, is blocking trying to pause any running scrubs but there are no stack traces of blocked tasks doing a scrub. After poking around with drgn, I noticed there was a scrub task that was constantly running and blocking for shorts periods of time: >>> t = find_task(prog, 1356190) >>> prog.stack_trace(t) #0 __schedule+0x5ce/0xcfc #1 schedule+0x46/0xe4 #2 schedule_timeout+0x1df/0x475 #3 btrfs_reada_wait+0xda/0x132 #4 scrub_stripe+0x2a8/0x112f #5 scrub_chunk+0xcd/0x134 #6 scrub_enumerate_chunks+0x29e/0x5ee #7 btrfs_scrub_dev+0x2d5/0x91b #8 btrfs_ioctl+0x7f5/0x36e7 #9 __x64_sys_ioctl+0x83/0xb0 #10 do_syscall_64+0x33/0x77 #11 entry_SYSCALL_64+0x7c/0x156 Which corresponds to: int btrfs_reada_wait(void *handle) { struct reada_control *rc = handle; struct btrfs_fs_info *fs_info = rc->fs_info; while (atomic_read(&rc->elems)) { if (!atomic_read(&fs_info->reada_works_cnt)) reada_start_machine(fs_info); wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0, (HZ + 9) / 10); } (...) So the counter "rc->elems" was set to 1 and never decreased to 0, causing the scrub task to loop forever in that function. Then I used the following script for drgn to check the readahead requests: $ cat dump_reada.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) def dump_re(re): nzones = re.nzones.value_() print(f're at {hex(re.value_())}') print(f'\t logical {re.logical.value_()}') print(f'\t refcnt {re.refcnt.value_()}') print(f'\t nzones {nzones}') for i in range(nzones): dev = re.zones[i].device name = dev.name.str.string_() print(f'\t\t dev id {dev.devid.value_()} name {name}') print() for _, e in radix_tree_for_each(fs_info.reada_tree): re = cast('struct reada_extent *', e) dump_re(re) $ drgn dump_reada.py re at 0xffff8f3da9d25ad8 logical 38928384 refcnt 1 nzones 1 dev id 0 name b'/dev/sdd' $ So there was one readahead extent with a single zone corresponding to the source device of that last device replace operation logged in dmesg/syslog. Also the ID of that zone's device was 0 which is a special value set in the source device of a device replace operation when the operation finishes (constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()), confirming again that device /dev/sdd was the source of a device replace operation. Normally there should be as many zones in the readahead extent as there are devices, and I wasn't expecting the extent to be in a block group with a 'single' profile, so I went and confirmed with the following drgn script that there weren't any single profile block groups: $ cat dump_block_groups.py import sys import drgn from drgn import NULL, Object, cast, container_of, execscript, \ reinterpret, sizeof from drgn.helpers.linux import * mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1" mnt = None for mnt in for_each_mount(prog, dst = mnt_path): pass if mnt is None: sys.stderr.write(f'Error: mount point {mnt_path} not found\n') sys.exit(1) fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info) BTRFS_BLOCK_GROUP_DATA = (1 << 0) BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1) BTRFS_BLOCK_GROUP_METADATA = (1 << 2) BTRFS_BLOCK_GROUP_RAID0 = (1 << 3) BTRFS_BLOCK_GROUP_RAID1 = (1 << 4) BTRFS_BLOCK_GROUP_DUP = (1 << 5) BTRFS_BLOCK_GROUP_RAID10 = (1 << 6) BTRFS_BLOCK_GROUP_RAID5 = (1 << 7) BTRFS_BLOCK_GROUP_RAID6 = (1 << 8) BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9) BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10) def bg_flags_string(bg): flags = bg.flags.value_() ret = '' if flags & BTRFS_BLOCK_GROUP_DATA: ret = 'data' if flags & BTRFS_BLOCK_GROUP_METADATA: if len(ret) > 0: ret += '|' ret += 'meta' if flags & BTRFS_BLOCK_GROUP_SYSTEM: if len(ret) > 0: ret += '|' ret += 'system' if flags & BTRFS_BLOCK_GROUP_RAID0: ret += ' raid0' elif flags & BTRFS_BLOCK_GROUP_RAID1: ret += ' raid1' elif flags & BTRFS_BLOCK_GROUP_DUP: ret += ' dup' elif flags & BTRFS_BLOCK_GROUP_RAID10: ret += ' raid10' elif flags & BTRFS_BLOCK_GROUP_RAID5: ret += ' raid5' elif flags & BTRFS_BLOCK_GROUP_RAID6: ret += ' raid6' elif flags & BTRFS_BLOCK_GROUP_RAID1C3: ret += ' raid1c3' elif flags & BTRFS_BLOCK_GROUP_RAID1C4: ret += ' raid1c4' else: ret += ' single' return ret def dump_bg(bg): print() print(f'block group at {hex(bg.value_())}') print(f'\t start {bg.start.value_()} length {bg.length.value_()}') print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}') bg_root = fs_info.block_group_cache_tree.address_of_() for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'): dump_bg(bg) $ drgn dump_block_groups.py block group at 0xffff8f3d673b0400 start 22020096 length 16777216 flags 258 - system raid6 block group at 0xffff8f3d53ddb400 start 38797312 length 536870912 flags 260 - meta raid6 block group at 0xffff8f3d5f4d9c00 start 575668224 length 2147483648 flags 257 - data raid6 block group at 0xffff8f3d08189000 start 2723151872 length 67108864 flags 258 - system raid6 block group at 0xffff8f3db70ff000 start 2790260736 length 1073741824 flags 260 - meta raid6 block group at 0xffff8f3d5f4dd800 start 3864002560 length 67108864 flags 258 - system raid6 block group at 0xffff8f3d67037000 start 3931111424 length 2147483648 flags 257 - data raid6 $ So there were only 2 reasons left for having a readahead extent with a single zone: reada_find_zone(), called when creating a readahead extent, returned NULL either because we failed to find the corresponding block group or because a memory allocation failed. With some additional and custom tracing I figured out that on every further ocurrence of the problem the block group had just been deleted when we were looping to create the zones for the readahead extent (at reada_find_extent()), so we ended up with only one zone in the readahead extent, corresponding to a device that ends up getting replaced. So after figuring that out it became obvious why the hang happens: 1) Task A starts a scrub on any device of the filesystem, except for device /dev/sdd; 2) Task B starts a device replace with /dev/sdd as the source device; 3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently starting to scrub a stripe from block group X. This call to btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add() calls reada_add_block(), it passes the logical address of the extent tree's root node as its 'logical' argument - a value of 38928384; 4) Task A then enters reada_find_extent(), called from reada_add_block(). It finds there isn't any existing readahead extent for the logical address 38928384, so it proceeds to the path of creating a new one. It calls btrfs_map_block() to find out which stripes exist for the block group X. On the first iteration of the for loop that iterates over the stripes, it finds the stripe for device /dev/sdd, so it creates one zone for that device and adds it to the readahead extent. Before getting into the second iteration of the loop, the cleanup kthread deletes block group X because it was empty. So in the iterations for the remaining stripes it does not add more zones to the readahead extent, because the calls to reada_find_zone() returned NULL because they couldn't find block group X anymore. As a result the new readahead extent has a single zone, corresponding to the device /dev/sdd; 4) Before task A returns to btrfs_reada_add() and queues the readahead job for the readahead work queue, task B finishes the device replace and at btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new device /dev/sdg; 5) Task A returns to reada_add_block(), which increments the counter "->elems" of the reada_control structure allocated at btrfs_reada_add(). Then it returns back to btrfs_reada_add() and calls reada_start_machine(). This queues a job in the readahead work queue to run the function reada_start_machine_worker(), which calls __reada_start_machine(). At __reada_start_machine() we take the device list mutex and for each device found in the current device list, we call reada_start_machine_dev() to start the readahead work. However at this point the device /dev/sdd was already freed and is not in the device list anymore. This means the corresponding readahead for the extent at 38928384 is never started, and therefore the "->elems" counter of the reada_control structure allocated at btrfs_reada_add() never goes down to 0, causing the call to btrfs_reada_wait(), done by the scrub task, to wait forever. Note that the readahead request can be made either after the device replace started or before it started, however in pratice it is very unlikely that a device replace is able to start after a readahead request is made and is able to complete before the readahead request completes - maybe only on a very small and nearly empty filesystem. This hang however is not the only problem we can have with readahead and device removals. When the readahead extent has other zones other than the one corresponding to the device that is being removed (either by a device replace or a device remove operation), we risk having a use-after-free on the device when dropping the last reference of the readahead extent. For example if we create a readahead extent with two zones, one for the device /dev/sdd and one for the device /dev/sde: 1) Before the readahead worker starts, the device /dev/sdd is removed, and the corresponding btrfs_device structure is freed. However the readahead extent still has the zone pointing to the device structure; 2) When the readahead worker starts, it only finds device /dev/sde in the current device list of the filesystem; 3) It starts the readahead work, at reada_start_machine_dev(), using the device /dev/sde; 4) Then when it finishes reading the extent from device /dev/sde, it calls __readahead_hook() which ends up dropping the last reference on the readahead extent through the last call to reada_extent_put(); 5) At reada_extent_put() it iterates over each zone of the readahead extent and attempts to delete an element from the device's 'reada_extents' radix tree, resulting in a use-after-free, as the device pointer of the zone for /dev/sdd is now stale. We can also access the device after dropping the last reference of a zone, through reada_zone_release(), also called by reada_extent_put(). And a device remove suffers the same problem, however since it shrinks the device size down to zero before removing the device, it is very unlikely to still have readahead requests not completed by the time we free the device, the only possibility is if the device has a very little space allocated. While the hang problem is exclusive to scrub, since it is currently the only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free problem affects any path that triggers readhead, which includes btree_readahead_hook() and __readahead_hook() (a readahead worker can trigger readahed for the children of a node) for example - any path that ends up calling reada_add_block() can trigger the use-after-free after a device is removed. So fix this by waiting for any readahead requests for a device to complete before removing a device, ensuring that while waiting for existing ones no new ones can be made. This problem has been around for a very long time - the readahead code was added in 2011, device remove exists since 2008 and device replace was introduced in 2013, hard to pick a specific commit for a git Fixes tag. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Filipe Manana 提交于
If we fail to find suitable zones for a new readahead extent, we end up leaving a stale pointer in the global readahead extents radix tree (fs_info->reada_tree), which can trigger the following trace later on: [13367.696354] BUG: kernel NULL pointer dereference, address: 00000000000000b0 [13367.696802] #PF: supervisor read access in kernel mode [13367.697249] #PF: error_code(0x0000) - not-present page [13367.697721] PGD 0 P4D 0 [13367.698171] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [13367.698632] CPU: 6 PID: 851214 Comm: btrfs Tainted: G W 5.9.0-rc6-btrfs-next-69 #1 [13367.699100] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [13367.700069] RIP: 0010:__lock_acquire+0x20a/0x3970 [13367.700562] Code: ff 1f 0f b7 c0 48 0f (...) [13367.701609] RSP: 0018:ffffb14448f57790 EFLAGS: 00010046 [13367.702140] RAX: 0000000000000000 RBX: 29b935140c15e8cf RCX: 0000000000000000 [13367.702698] RDX: 0000000000000002 RSI: ffffffffb3d66bd0 RDI: 0000000000000046 [13367.703240] RBP: ffff8a52ba8ac040 R08: 00000c2866ad9288 R09: 0000000000000001 [13367.703783] R10: 0000000000000001 R11: 00000000b66d9b53 R12: ffff8a52ba8ac9b0 [13367.704330] R13: 0000000000000000 R14: ffff8a532b6333e8 R15: 0000000000000000 [13367.704880] FS: 00007fe1df6b5700(0000) GS:ffff8a5376600000(0000) knlGS:0000000000000000 [13367.705438] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [13367.705995] CR2: 00000000000000b0 CR3: 000000022cca8004 CR4: 00000000003706e0 [13367.706565] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [13367.707127] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [13367.707686] Call Trace: [13367.708246] ? ___slab_alloc+0x395/0x740 [13367.708820] ? reada_add_block+0xae/0xee0 [btrfs] [13367.709383] lock_acquire+0xb1/0x480 [13367.709955] ? reada_add_block+0xe0/0xee0 [btrfs] [13367.710537] ? reada_add_block+0xae/0xee0 [btrfs] [13367.711097] ? rcu_read_lock_sched_held+0x5d/0x90 [13367.711659] ? kmem_cache_alloc_trace+0x8d2/0x990 [13367.712221] ? lock_acquired+0x33b/0x470 [13367.712784] _raw_spin_lock+0x34/0x80 [13367.713356] ? reada_add_block+0xe0/0xee0 [btrfs] [13367.713966] reada_add_block+0xe0/0xee0 [btrfs] [13367.714529] ? btrfs_root_node+0x15/0x1f0 [btrfs] [13367.715077] btrfs_reada_add+0x117/0x170 [btrfs] [13367.715620] scrub_stripe+0x21e/0x10d0 [btrfs] [13367.716141] ? kvm_sched_clock_read+0x5/0x10 [13367.716657] ? __lock_acquire+0x41e/0x3970 [13367.717184] ? scrub_chunk+0x60/0x140 [btrfs] [13367.717697] ? find_held_lock+0x32/0x90 [13367.718254] ? scrub_chunk+0x60/0x140 [btrfs] [13367.718773] ? lock_acquired+0x33b/0x470 [13367.719278] ? scrub_chunk+0xcd/0x140 [btrfs] [13367.719786] scrub_chunk+0xcd/0x140 [btrfs] [13367.720291] scrub_enumerate_chunks+0x270/0x5c0 [btrfs] [13367.720787] ? finish_wait+0x90/0x90 [13367.721281] btrfs_scrub_dev+0x1ee/0x620 [btrfs] [13367.721762] ? rcu_read_lock_any_held+0x8e/0xb0 [13367.722235] ? preempt_count_add+0x49/0xa0 [13367.722710] ? __sb_start_write+0x19b/0x290 [13367.723192] btrfs_ioctl+0x7f5/0x36f0 [btrfs] [13367.723660] ? __fget_files+0x101/0x1d0 [13367.724118] ? find_held_lock+0x32/0x90 [13367.724559] ? __fget_files+0x101/0x1d0 [13367.724982] ? __x64_sys_ioctl+0x83/0xb0 [13367.725399] __x64_sys_ioctl+0x83/0xb0 [13367.725802] do_syscall_64+0x33/0x80 [13367.726188] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [13367.726574] RIP: 0033:0x7fe1df7add87 [13367.726948] Code: 00 00 00 48 8b 05 09 91 (...) [13367.727763] RSP: 002b:00007fe1df6b4d48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [13367.728179] RAX: ffffffffffffffda RBX: 000055ce1fb596a0 RCX: 00007fe1df7add87 [13367.728604] RDX: 000055ce1fb596a0 RSI: 00000000c400941b RDI: 0000000000000003 [13367.729021] RBP: 0000000000000000 R08: 00007fe1df6b5700 R09: 0000000000000000 [13367.729431] R10: 00007fe1df6b5700 R11: 0000000000000246 R12: 00007ffd922b07de [13367.729842] R13: 00007ffd922b07df R14: 00007fe1df6b4e40 R15: 0000000000802000 [13367.730275] Modules linked in: btrfs blake2b_generic xor (...) [13367.732638] CR2: 00000000000000b0 [13367.733166] ---[ end trace d298b6805556acd9 ]--- What happens is the following: 1) At reada_find_extent() we don't find any existing readahead extent for the metadata extent starting at logical address X; 2) So we proceed to create a new one. We then call btrfs_map_block() to get information about which stripes contain extent X; 3) After that we iterate over the stripes and create only one zone for the readahead extent - only one because reada_find_zone() returned NULL for all iterations except for one, either because a memory allocation failed or it couldn't find the block group of the extent (it may have just been deleted); 4) We then add the new readahead extent to the readahead extents radix tree at fs_info->reada_tree; 5) Then we iterate over each zone of the new readahead extent, and find that the device used for that zone no longer exists, because it was removed or it was the source device of a device replace operation. Since this left 'have_zone' set to 0, after finishing the loop we jump to the 'error' label, call kfree() on the new readahead extent and return without removing it from the radix tree at fs_info->reada_tree; 6) Any future call to reada_find_extent() for the logical address X will find the stale pointer in the readahead extents radix tree, increment its reference counter, which can trigger the use-after-free right away or return it to the caller reada_add_block() that results in the use-after-free of the example trace above. So fix this by making sure we delete the readahead extent from the radix tree if we fail to setup zones for it (when 'have_zone = 0'). Fixes: 31945021 ("btrfs: reada: bypass adding extent when all zone failed") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: NJosef Bacik <josef@toxicpanda.com> Signed-off-by: NFilipe Manana <fdmanana@suse.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Daniel Xu 提交于
If there's no parity and num_stripes < ncopies, a crafted image can trigger a division by zero in calc_stripe_length(). The image was generated through fuzzing. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: NQu Wenruo <wqu@suse.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209587Signed-off-by: NDaniel Xu <dxu@dxuuu.xyz> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Pujin Shi 提交于
This patch addresses a compile warning: fs/btrfs/extent-tree.c: In function '__btrfs_free_extent': fs/btrfs/extent-tree.c:3187:4: warning: format '%lu' expects argument of type 'long unsigned int', but argument 8 has type 'unsigned int' [-Wformat=] Fixes: 1c2a07f5 ("btrfs: extent-tree: kill BUG_ON() in __btrfs_free_extent()") Reviewed-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NPujin Shi <shipujin.t@gmail.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com>
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由 Josef Bacik 提交于
Dave reported a problem with my rwsem conversion patch where we got the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.9.0-default+ #1297 Not tainted ------------------------------------------------------ kswapd0/76 is trying to acquire lock: ffff9d5d25df2530 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] but task is already holding lock: ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (fs_reclaim){+.+.}-{0:0}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 fs_reclaim_acquire.part.0+0x25/0x30 kmem_cache_alloc+0x30/0x9c0 alloc_inode+0x81/0x90 iget_locked+0xcd/0x1a0 kernfs_get_inode+0x1b/0x130 kernfs_get_tree+0x136/0x210 sysfs_get_tree+0x1a/0x50 vfs_get_tree+0x1d/0xb0 path_mount+0x70f/0xa80 do_mount+0x75/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #3 (kernfs_mutex){+.+.}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 __mutex_lock+0xa0/0xaf0 kernfs_add_one+0x23/0x150 kernfs_create_dir_ns+0x58/0x80 sysfs_create_dir_ns+0x70/0xd0 kobject_add_internal+0xbb/0x2d0 kobject_add+0x7a/0xd0 btrfs_sysfs_add_block_group_type+0x141/0x1d0 [btrfs] btrfs_read_block_groups+0x1f1/0x8c0 [btrfs] open_ctree+0x981/0x1108 [btrfs] btrfs_mount_root.cold+0xe/0xb0 [btrfs] legacy_get_tree+0x2d/0x60 vfs_get_tree+0x1d/0xb0 fc_mount+0xe/0x40 vfs_kern_mount.part.0+0x71/0x90 btrfs_mount+0x13b/0x3e0 [btrfs] legacy_get_tree+0x2d/0x60 vfs_get_tree+0x1d/0xb0 path_mount+0x70f/0xa80 do_mount+0x75/0x90 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #2 (btrfs-extent-00){++++}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 down_read_nested+0x45/0x220 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot+0x6d4/0xfd0 [btrfs] check_committed_ref+0x69/0x200 [btrfs] btrfs_cross_ref_exist+0x65/0xb0 [btrfs] run_delalloc_nocow+0x446/0x9b0 [btrfs] btrfs_run_delalloc_range+0x61/0x6a0 [btrfs] writepage_delalloc+0xae/0x160 [btrfs] __extent_writepage+0x262/0x420 [btrfs] extent_write_cache_pages+0x2b6/0x510 [btrfs] extent_writepages+0x43/0x90 [btrfs] do_writepages+0x40/0xe0 __writeback_single_inode+0x62/0x610 writeback_sb_inodes+0x20f/0x500 wb_writeback+0xef/0x4a0 wb_do_writeback+0x49/0x2e0 wb_workfn+0x81/0x340 process_one_work+0x233/0x5d0 worker_thread+0x50/0x3b0 kthread+0x137/0x150 ret_from_fork+0x1f/0x30 -> #1 (btrfs-fs-00){++++}-{3:3}: __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 down_read_nested+0x45/0x220 __btrfs_tree_read_lock+0x35/0x1c0 [btrfs] __btrfs_read_lock_root_node+0x3a/0x50 [btrfs] btrfs_search_slot+0x6d4/0xfd0 [btrfs] btrfs_lookup_inode+0x3a/0xc0 [btrfs] __btrfs_update_delayed_inode+0x93/0x2c0 [btrfs] __btrfs_commit_inode_delayed_items+0x7de/0x850 [btrfs] __btrfs_run_delayed_items+0x8e/0x140 [btrfs] btrfs_commit_transaction+0x367/0xbc0 [btrfs] btrfs_mksubvol+0x2db/0x470 [btrfs] btrfs_mksnapshot+0x7b/0xb0 [btrfs] __btrfs_ioctl_snap_create+0x16f/0x1a0 [btrfs] btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs] btrfs_ioctl+0xd0b/0x2690 [btrfs] __x64_sys_ioctl+0x6f/0xa0 do_syscall_64+0x2d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 -> #0 (&delayed_node->mutex){+.+.}-{3:3}: check_prev_add+0x91/0xc60 validate_chain+0xa6e/0x2a20 __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 __mutex_lock+0xa0/0xaf0 __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] btrfs_evict_inode+0x3cc/0x560 [btrfs] evict+0xd6/0x1c0 dispose_list+0x48/0x70 prune_icache_sb+0x54/0x80 super_cache_scan+0x121/0x1a0 do_shrink_slab+0x16d/0x3b0 shrink_slab+0xb1/0x2e0 shrink_node+0x230/0x6a0 balance_pgdat+0x325/0x750 kswapd+0x206/0x4d0 kthread+0x137/0x150 ret_from_fork+0x1f/0x30 other info that might help us debug this: Chain exists of: &delayed_node->mutex --> kernfs_mutex --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(kernfs_mutex); lock(fs_reclaim); lock(&delayed_node->mutex); *** DEADLOCK *** 3 locks held by kswapd0/76: #0: ffffffffa40cbba0 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30 #1: ffffffffa40b8b58 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x54/0x2e0 #2: ffff9d5d322390e8 (&type->s_umount_key#26){++++}-{3:3}, at: trylock_super+0x16/0x50 stack backtrace: CPU: 2 PID: 76 Comm: kswapd0 Not tainted 5.9.0-default+ #1297 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0x77/0x97 check_noncircular+0xff/0x110 ? save_trace+0x50/0x470 check_prev_add+0x91/0xc60 validate_chain+0xa6e/0x2a20 ? save_trace+0x50/0x470 __lock_acquire+0x582/0xac0 lock_acquire+0xca/0x430 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] __mutex_lock+0xa0/0xaf0 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] ? __lock_acquire+0x582/0xac0 ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] ? btrfs_evict_inode+0x30b/0x560 [btrfs] ? __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] __btrfs_release_delayed_node.part.0+0x3f/0x320 [btrfs] btrfs_evict_inode+0x3cc/0x560 [btrfs] evict+0xd6/0x1c0 dispose_list+0x48/0x70 prune_icache_sb+0x54/0x80 super_cache_scan+0x121/0x1a0 do_shrink_slab+0x16d/0x3b0 shrink_slab+0xb1/0x2e0 shrink_node+0x230/0x6a0 balance_pgdat+0x325/0x750 kswapd+0x206/0x4d0 ? finish_wait+0x90/0x90 ? balance_pgdat+0x750/0x750 kthread+0x137/0x150 ? kthread_mod_delayed_work+0xc0/0xc0 ret_from_fork+0x1f/0x30 This happens because we are still holding the path open when we start adding the sysfs files for the block groups, which creates a dependency on fs_reclaim via the tree lock. Fix this by dropping the path before we start doing anything with sysfs. Reported-by: NDavid Sterba <dsterba@suse.com> CC: stable@vger.kernel.org # 5.8+ Reviewed-by: NAnand Jain <anand.jain@oracle.com> Reviewed-by: NFilipe Manana <fdmanana@suse.com> Signed-off-by: NJosef Bacik <josef@toxicpanda.com> Reviewed-by: NDavid Sterba <dsterba@suse.com> Signed-off-by: NDavid Sterba <dsterba@suse.com> -
由 Joe Perches 提交于
Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.plSigned-off-by: NJoe Perches <joe@perches.com> Reviewed-by: NNick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: NMiguel Ojeda <ojeda@kernel.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> -
由 Jens Axboe 提交于
io_poll_double_wake() is called for both request types - both pure poll requests, and internal polls. This means that we should be using the right handler based on the request type. Use the one that the original caller already assigned for the waitqueue handling, that will always match the correct type. Cc: stable@vger.kernel.org # v5.8+ Reported-by: NPavel Begunkov <asml.silence@gmail.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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