• Y
    ext4: Fix warning in ext4_da_release_space · 782a6ba7
    Ye Bin 提交于
    hulk inclusion
    category: bugfix
    bugzilla: https://gitee.com/openeuler/kernel/issues/I58KLD
    CVE: NA
    
    ---------------------------
    
    We got issue as follows:
    WARNING: CPU: 2 PID: 1936 at fs/ext4/inode.c:1511 ext4_da_release_space+0x1b9/0x266
    Modules linked in:
    CPU: 2 PID: 1936 Comm: dd Not tainted 5.10.0+ #344
    RIP: 0010:ext4_da_release_space+0x1b9/0x266
    RSP: 0018:ffff888127307848 EFLAGS: 00010292
    RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff843f67cc
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffed1024e60ed9
    RBP: ffff888124dc8140 R08: 0000000000000083 R09: ffffed1075da6d23
    R10: ffff8883aed36917 R11: ffffed1075da6d22 R12: ffff888124dc83f0
    R13: ffff888124dc844c R14: ffff888124dc8168 R15: 000000000000000c
    FS:  00007f6b7247d740(0000) GS:ffff8883aed00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007ffc1a0b7dd8 CR3: 00000001065ce000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     ext4_es_remove_extent+0x187/0x230
     mpage_release_unused_pages+0x3af/0x470
     ext4_writepages+0xb9b/0x1160
     do_writepages+0xbb/0x1e0
     __filemap_fdatawrite_range+0x1b1/0x1f0
     file_write_and_wait_range+0x80/0xe0
     ext4_sync_file+0x13d/0x800
     vfs_fsync_range+0x75/0x140
     do_fsync+0x4d/0x90
     __x64_sys_fsync+0x1d/0x30
     do_syscall_64+0x33/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
    
    Above issue may happens as follows:
    	process1                        process2
    ext4_da_write_begin
      ext4_da_reserve_space
        ext4_es_insert_delayed_block[1/1]
                                        ext4_da_write_begin
    				      ext4_es_insert_delayed_block[0/1]
    ext4_writepages
      ****Delayed block allocation failed****
      mpage_release_unused_pages
        ext4_es_remove_extent[1/1]
          ext4_da_release_space [reserved 0]
    
    ext4_da_write_begin
      ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)
       ->As there exist [0, 1] extent, so will return true
                                       ext4_writepages
    				   ****Delayed block allocation failed****
                                         mpage_release_unused_pages
    				       ext4_es_remove_extent[0/1]
    				         ext4_da_release_space [reserved 1]
    					   ei->i_reserved_data_blocks [1->0]
    
      ext4_es_insert_delayed_block[1/1]
    
    ext4_writepages
      ****Delayed block allocation failed****
      mpage_release_unused_pages
      ext4_es_remove_extent[1/1]
       ext4_da_release_space [reserved 1]
        ei->i_reserved_data_blocks[0, -1]
        ->As ei->i_reserved_data_blocks already is zero but to_free is 1,
        will trigger warning.
    
    To solve above issue, introduce i_clu_lock to protect insert delayed
    block and remove block under cluster delay allocate mode.
    Signed-off-by: NYe Bin <yebin10@huawei.com>
    Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
    Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
    782a6ba7
super.c 194.6 KB