I noticed this problem while testing Lustre 2.15 client on a system with 2.12.6 servers.

The behavior is different with csh and bash.  With csh, ./a.out isn't there until I run the ls.  With bash, it runs after the ELF interpreter error.  This is reproducible every time.

• csh case (a.out not found until the ls is run)

$ gcc hello.c

$ ./a.out

./a.out: Command not found

$ ./a.out

./a.out: Command not found

$ ./a.out

./a.out: Command not found

$ ls a.out

a.out

$ ./a.out

hello world

• bash case (a.out works after the bad ELF interpreter error)

$ gcc hello.c

$ ./a.out

bash: ./a.out: /lib64/ld-linux-x86-64.so.2: bad ELF interpreter: No such file or directory

$ ./a.out

hello world

The main thing I've noticed in the client debug log:

running a.out

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 0, count: 80

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 6456, count: 1984

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 6186, count: 268

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 64, count: 504

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 568, count: 200

running a.out again

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 0, count: 128

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 64, count: 504

file.c:2012:ll_file_read_iter() file a.out:[0x2000XXXXX:0x9:0x0], ppos: 568, count: 28