[SSHD-100] [sftp] open(2) w/ O_CREAT|O_TRUNC works, but O_CREAT alone fails

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.6.0
• Assignee: Guillaume Nodet
• Reporter: Bobby Powers
• Created: 03/Dec/10 23:32
• Updated: 08/Dec/10 12:28
• Resolved: 08/Dec/10 12:19

Description

Hi folks,

I've mounted an sftp directory using sshfs like so:

1. sshfs -d -p 9022 bpowers@$SERVER_NAME:/bpowers /home/bpowers/Desktop/wintest

The following sequences of commands shows the problem:
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# rm -f bar
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# touch bar
touch: cannot touch `bar': No such file or directory
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# echo "foo" > bar
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# cat bar
foo
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# rm bar
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# touch bar
touch: cannot touch `bar': No such file or directory
...

I've reduced it to a simple test case. Running the attached program gives me the following:
root@bpowers-laptop:/home/bpowers/Desktop/wintest/test# /home/bpowers/creat_test
/home/bpowers/Desktop/wintest/test/abc2: No such file or directory
/home/bpowers/Desktop/wintest/test/abc3: worked.

The difference is in the flags passed to open(2), and the consequence of this is that I cannot use cp or rsync to create any files over sftp (although they will update existing files).

see attachment for the source of creat_test, which can be compiled with:
$ gcc -o creat_test test.c
and
$ man 2 open
for a description of the flags.

Debugging output from sshfs shows the following:

unique: 39, opcode: LOOKUP (1), nodeid: 1, insize: 45
LOOKUP /test
getattr /test
     NODEID: 2
     unique: 39, success, outsize: 144
unique: 40, opcode: LOOKUP (1), nodeid: 2, insize: 45
LOOKUP /test/abc2
getattr /test/abc2
     unique: 40, error: -2 (No such file or directory), outsize: 16
unique: 41, opcode: CREATE (35), nodeid: 2, insize: 61
create flags: 0x8041 /test/abc2 0100644 umask=0022
     unique: 41, error: -2 (No such file or directory), outsize: 16

unique: 42, opcode: LOOKUP (1), nodeid: 2, insize: 45
LOOKUP /test/abc3
getattr /test/abc3
     unique: 42, error: -2 (No such file or directory), outsize: 16
unique: 43, opcode: CREATE (35), nodeid: 2, insize: 61
create flags: 0x8241 /test/abc3 0100644 umask=0022
     create[25271456] flags: 0x8241 /test/abc3
fgetattr[25271456] /test/abc3
     NODEID: 4
     unique: 43, success, outsize: 160
unique: 44, opcode: FLUSH (25), nodeid: 4, insize: 64
flush[25271456]
     unique: 44, success, outsize: 16
unique: 45, opcode: RELEASE (18), nodeid: 4, insize: 64
release[25271456] flags: 0x8001
     unique: 45, success, outsize: 16