From: Changwei Ge <chge@xxxxxxxxxxxxxxxxx> Subject: ocfs2: no need try to truncate file beyond i_size Linux fallocate(2) with FALLOC_FL_PUNCH_HOLE mode set, its offset can exceed inode size. Ocfs2 now does't allow that offset beyond inode size. This restriction is not necessary and voilates fallocate(2) semantics. If fallocate(2) offset is beyond inode size, just return success and do nothing further. Otherwise, ocfs2 will crash the kernel. kernel BUG at fs/ocfs2//alloc.c:7264! ocfs2_truncate_inline+0x20f/0x360 [ocfs2] ? ocfs2_read_blocks+0x2f3/0x5f0 [ocfs2] ocfs2_remove_inode_range+0x23c/0xcb0 [ocfs2] ? ocfs2_read_inode_block+0x10/0x20 [ocfs2] ? ocfs2_allocate_extend_trans+0x1a0/0x1a0 [ocfs2] __ocfs2_change_file_space+0x4a5/0x650 [ocfs2] ocfs2_fallocate+0x83/0xa0 [ocfs2] ? __audit_syscall_entry+0xb8/0x100 ? __sb_start_write+0x3b/0x70 vfs_fallocate+0x148/0x230 SyS_fallocate+0x48/0x80 do_syscall_64+0x79/0x170 Link: http://lkml.kernel.org/r/20200407082754.17565-1-chge@xxxxxxxxxxxxxxxxx Signed-off-by: Changwei Ge <chge@xxxxxxxxxxxxxxxxx> Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx> Cc: Mark Fasheh <mark@xxxxxxxxxx> Cc: Joel Becker <jlbec@xxxxxxxxxxxx> Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Cc: Changwei Ge <gechangwei@xxxxxxx> Cc: Gang He <ghe@xxxxxxxx> Cc: Jun Piao <piaojun@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ocfs2/alloc.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/ocfs2/alloc.c~ocfs2-no-need-try-to-truncate-file-beyond-i_size +++ a/fs/ocfs2/alloc.c @@ -7402,6 +7402,10 @@ int ocfs2_truncate_inline(struct inode * struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; struct ocfs2_inline_data *idata = &di->id2.i_data; + /* No need to punch hole beyond i_size. */ + if (start >= i_size_read(inode)) + return 0; + if (end > i_size_read(inode)) end = i_size_read(inode); _
