From: Baokun Li libaokun1@huawei.com
stable inclusion from stable-v5.10.132 commit 91f90b571f1a23f5b8a9c2b68a9aa5d6981a3c3d category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YS3T
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit f87c7a4b084afc13190cbb263538e444cb2b392a upstream.
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 Signed-off-by: Tadeusz Struk tadeusz.struk@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- fs/ext4/extents.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 0f93d72d9301..1a4ac8aa1e96 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4703,6 +4703,11 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) return -EOPNOTSUPP;
ext4_fc_start_update(inode); + inode_lock(inode); + ret = ext4_convert_inline_data(inode); + inode_unlock(inode); + if (ret) + goto exit;
inode_lock(inode); ret = ext4_convert_inline_data(inode);