When path is truncated by PATH_MAX limitation, it causes QEMU to access
incorrect file. So use original full path instead of PATH_MAX within
9pfs (need check/process ENOMEM for related memory allocation).
The related test:
- Environments (for qemu-devel):
- Host is under fedora17 desktop with ext4fs:
qemu-system-x86_64 -hda test.img -m 1024 \
-net nic,vlan=4,model=virtio,macaddr=00:16:35:AF:94:04 \
-net tap,vlan=4,ifname=tap4,script=no,downscript=no \
-device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=hostshare \
-fsdev local,security_model=passthrough,id=fsdev0,\
path=/upstream/vm/data/share/1234567890abcdefghijklmnopqrstuvwxyz\
ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmnopqrstuvwxyz\
ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111111111\
1111111111111111111111111111111111111111111111111111222222222222\
2222222222222222222222222222222222222222222222222222222222222222\
2222222222222222222222222222222222233333333333333333333333333333\
3333333333333333333333333333333333
- Guest is ubuntu12 server with 9pfs.
mount -t 9p -o trans=virtio,version=9p2000.L hostshare /share
- Limitations:
full path limitation is PATH_MAX (4096B include nul) under Linux.
file/dir node name maximized length is 256 (include nul) under ext4.
- Special test:
Under host, modify the file: "/upstream/vm/data/share/1234567890abcdefg\
hijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmno\
pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111\
111111111111111111111111111111111111111111111111111111111122222222222\
222222222222222222222222222222222222222222222222222222222222222222222\
222222222222222222222222222222233333333333333333333333333333333333333\
3333333333333333333333333/4444444444444444444444444444444444444444444\
444444444444444444444444444444444444444444444444444444444444444444444\
444444444444444444444444444444444444444444444444444444444444444444444\
444444444444444444444444444444444444444/55555555555555555555555555555\
555555555555555555555555555555555555555555555555555555555555555555555\
555555555555555555555555555555555555555555555555555555555555555555555\
555555555555555555555555555555555555555555555555555555555555555555555\
55555555/666666666666666666666666666666666666666666666666666666666666\
666666666666666666666666666666666666666666666666666666666666666666666\
666666666666666666666666666666666666666666666666666666666666666666666\
666666666666666666666/77777777777777777777777777777777777777777777777\
777777777777777777777777777777777777777777777777777777777777777777777\
777777777777777777777777777777777777777777777777777777777777777777777\
77777777777777777777777777777777777777777777777777777777777/888888888\
888888888888888888888888888888888888888888888888888888888888888888888\
888888888888888888888888888888888888888888888888888888888888888888888\
888888888888888888888888888888888888888888888888888888888888888888888\
888888888/99999999999999999999999999999999999999999999999999999999999\
999999999999999999999999999999999999999999999999999999999999999999999\
999999999999999999999999999999999999999999999999999999999999999999999\
99999999999999999999999999999999999999999/000000000000000000000000000\
000000000000000000000000000000000000000000000000000000000000000000000\
000000000000000000000000000000000000000000000000000000000000000000000\
000000000000000000000000000000000000000000000000/aaaaaaaaaaaaaaaaaaaa\
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbb\
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/ccccccccc\
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
cccccccccc/dddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
dddddddddddddddddddddd/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee/fffffffffffffff\
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff/gggggggggg\
ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
ggggggggggggggggggggggg/iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii/jjjjjjjjjjjjj\
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj\
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj/ppppppppppppppppppppp\
ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp\
ppppppppppppppppppppppppppppppppppppppp/test1234567890file.log"
(need enter dir firstly, then modify file, or can not open it).
Under guest, still allow modify "test1234567890file.log" (will generate
"test123456" file with contents).
After apply this patch, can not open "test1234567890file.log" under guest
(permission denied).
- Common test:
All are still OK after apply this path.
"mkdir -p", "create/open file/dir", "modify file/dir", "rm file/dir".
change various mount point paths under host and/or guest.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Add a new context flag PATHNAME_FSCONTEXT and indicate whether
the fs driver track fid using path names. Also add a private
pointer that help us to track fs driver specific values in there
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This enables us to add handles to track fids later. The
V9fsPath added is similar to V9fsString except that the
size include the NULL byte also.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
On rename we take the write lock and this ensure path
doesn't change as we operate on them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
