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| author |   Baokun Li <libaokun1@huawei.com> | 2022-04-28 21:40:31 +0800 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2022-05-17 14:17:40 -0400 |
| commit | f87c7a4b084afc13190cbb263538e444cb2b392a (patch) | |
| tree | 59e874179b996c2935ecb0a7db292fefc7aecf6b /fs/ext4/inode.c | |
| parent | ext4: convert symlink external data block mapping to bdev (diff) | |
| download | linux-dev-f87c7a4b084afc13190cbb263538e444cb2b392a.tar.xz linux-dev-f87c7a4b084afc13190cbb263538e444cb2b392a.zip | |
ext4: fix race condition between ext4_write and ext4_convert_inline_data
Hulk Robot reported a BUG_ON:
==================================================================
EXT4-fs error (device loop3): ext4_mb_generate_buddy:805: group 0,
block bitmap and bg descriptor inconsistent: 25 vs 31513 free clusters
kernel BUG at fs/ext4/ext4_jbd2.c:53!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 25371 Comm: syz-executor.3 Not tainted 5.10.0+ #1
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:53 [inline]
RIP: 0010:__ext4_journal_stop+0x10e/0x110 fs/ext4/ext4_jbd2.c:116
[...]
Call Trace:
ext4_write_inline_data_end+0x59a/0x730 fs/ext4/inline.c:795
generic_perform_write+0x279/0x3c0 mm/filemap.c:3344
ext4_buffered_write_iter+0x2e3/0x3d0 fs/ext4/file.c:270
ext4_file_write_iter+0x30a/0x11c0 fs/ext4/file.c:520
do_iter_readv_writev+0x339/0x3c0 fs/read_write.c:732
do_iter_write+0x107/0x430 fs/read_write.c:861
vfs_writev fs/read_write.c:934 [inline]
do_pwritev+0x1e5/0x380 fs/read_write.c:1031
[...]
==================================================================
Above issue may happen as follows:
cpu1 cpu2
__________________________|__________________________
do_pwritev
vfs_writev
do_iter_write
ext4_file_write_iter
ext4_buffered_write_iter
generic_perform_write
ext4_da_write_begin
vfs_fallocate
ext4_fallocate
ext4_convert_inline_data
ext4_convert_inline_data_nolock
ext4_destroy_inline_data_nolock
clear EXT4_STATE_MAY_INLINE_DATA
ext4_map_blocks
ext4_ext_map_blocks
ext4_mb_new_blocks
ext4_mb_regular_allocator
ext4_mb_good_group_nolock
ext4_mb_init_group
ext4_mb_init_cache
ext4_mb_generate_buddy --> error
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_restore_inline_data
set EXT4_STATE_MAY_INLINE_DATA
ext4_block_write_begin
ext4_da_write_end
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_write_inline_data_end
handle=NULL
ext4_journal_stop(handle)
__ext4_journal_stop
ext4_put_nojournal(handle)
ref_cnt = (unsigned long)handle
BUG_ON(ref_cnt == 0) ---> BUG_ON
The lock held by ext4_convert_inline_data is xattr_sem, but the lock
held by generic_perform_write is i_rwsem. Therefore, the two locks can
be concurrent.
To solve above issue, we add inode_lock() for ext4_convert_inline_data().
At the same time, move ext4_convert_inline_data() in front of
ext4_punch_hole(), remove similar handling from ext4_punch_hole().
Fixes: 0c8d414f163f ("ext4: let fallocate handle inline data correctly")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220428134031.4153381-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 9 |
1 files changed, 0 insertions, 9 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5948bbba28e3..890f769d6e20 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3979,15 +3979,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) trace_ext4_punch_hole(inode, offset, length, 0); - ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); - if (ext4_has_inline_data(inode)) { - filemap_invalidate_lock(mapping); - ret = ext4_convert_inline_data(inode); - filemap_invalidate_unlock(mapping); - if (ret) - return ret; - } - /* * Write out all dirty pages to avoid race conditions * Then release them. |