hulk inclusion category: feature bugzilla: 189105, https://gitee.com/openeuler/kernel/issues/I7TN3J
--------------------------------
There's a issue as follows: Block Allocation Reservation Windows Map (ext2_try_to_allocate_with_rsv): reservation window 0x000000006f105382 start: 0, end: 0 reservation window 0x000000008fd1a555 start: 1044, end: 1059 Window map complete. kernel BUG at fs/ext2/balloc.c:1158! invalid opcode: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:ext2_try_to_allocate_with_rsv.isra.0+0x15c4/0x1800 Call Trace: <TASK> ext2_new_blocks+0x935/0x1690 ext2_new_block+0x73/0xa0 ext2_xattr_set2+0x74f/0x1730 ext2_xattr_set+0x12b6/0x2260 ext2_xattr_user_set+0x9c/0x110 __vfs_setxattr+0x139/0x1d0 __vfs_setxattr_noperm+0xfc/0x370 __vfs_setxattr_locked+0x205/0x2c0 vfs_setxattr+0x19d/0x3b0 do_setxattr+0xff/0x220 setxattr+0x123/0x150 path_setxattr+0x193/0x1e0 __x64_sys_setxattr+0xc8/0x170 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Above issue may happens as follows: setxattr write back ext2_xattr_set ext2_xattr_set2 ext2_new_block ext2_new_blocks ext2_try_to_allocate_with_rsv alloc_new_reservation --> group=0 [0, 1023] rsv [1016, 1023] do_writepages mpage_writepages write_cache_pages __mpage_writepage ext2_get_block ext2_get_blocks ext2_alloc_branch ext2_new_blocks ext2_try_to_allocate_with_rsv alloc_new_reservation -->group=1 [1024, 2047] rsv [1044, 1059] if ((my_rsv->rsv_start > group_last_block) || (my_rsv->rsv_end < group_first_block) rsv_window_dump BUG(); Now ext2 mkwrite delay allocate new blocks. So there maybe allocate blocks when do write back. However, there is no concurrent protection between ext2_xattr_set() and do_writepages(). To solve about issue don't use reservation window when allocate block for xattr.
Signed-off-by: Ye Bin yebin10@huawei.com --- fs/ext2/balloc.c | 15 +++++++++------ fs/ext2/xattr.c | 4 ++-- 2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index c55f4d0f7cc1..4e9a8e996041 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1276,13 +1276,16 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, * it's a regular file, and * the desired window size is greater than 0 (One could use ioctl * command EXT2_IOC_SETRSVSZ to set the window size to 0 to turn off - * reservation on that particular file) + * reservation on that particular file), and unspecified Do not use + * reservation window. */ - block_i = EXT2_I(inode)->i_block_alloc_info; - if (block_i) { - windowsz = block_i->rsv_window_node.rsv_goal_size; - if (windowsz > 0) - my_rsv = &block_i->rsv_window_node; + if (!(flag & EXT2_ALLOC_NORESERVE)) { + block_i = EXT2_I(inode)->i_block_alloc_info; + if (block_i) { + windowsz = block_i->rsv_window_node.rsv_goal_size; + if (windowsz > 0) + my_rsv = &block_i->rsv_window_node; + } }
if (!ext2_has_free_blocks(sbi)) { diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index 4d66c25a62a6..742f7c4cc6d8 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -669,8 +669,8 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, ext2_fsblk_t goal = ext2_group_first_block_no(sb, EXT2_I(inode)->i_block_group); unsigned long count = 1; - int block = ext2_new_blocks(inode, goal, &count, - &error, 0); + int block = ext2_new_blocks(inode, goal, &count, &error, + EXT2_ALLOC_NORESERVE); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block);