kernel-hacking-2024-linux-s.../Documentation/filesystems
Latchesar Ionkov ba17674fe0 9p: attach-per-user
The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.

Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.

This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):

- attach-per-user (access=user) (default mode for 9P2000.u)
 If a user tries to access a file served by v9fs for the first time, v9fs
 sends an attach command to the server (Tattach) specifying the user. If
 the attach succeeds, the user can access the v9fs tree.
 As there is no uname->uid (string->integer) mapping yet, this mode works
 only with the 9P2000.u dialect.

- allow only one user to access the tree (access=<uid>)
 Only the user with uid can access the v9fs tree. Other users that attempt
 to access it will get EPERM error.

- do all operations as a single user (access=any) (default for 9P2000)
 V9fs does a single attach and all operations are done as a single user.
 If this mode is selected, the v9fs behavior is identical with the current
 one.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2007-10-17 14:31:07 -05:00
..
configfs some kmalloc/memset ->kzalloc (tree wide) 2007-07-19 10:04:50 -07:00
00-INDEX Documentation: add entries to filesystems/00-INDEX for several untracked files 2007-10-17 08:43:05 -07:00
9p.txt 9p: attach-per-user 2007-10-17 14:31:07 -05:00
adfs.txt
affs.txt
afs.txt
automount-support.txt
befs.txt
bfs.txt
cifs.txt
coda.txt
cramfs.txt
dentry-locking.txt
directory-locking
dlmfs.txt
ecryptfs.txt
Exporting
ext2.txt
ext3.txt
ext4.txt
files.txt
fuse.txt
gfs2.txt
hfs.txt
hfsplus.txt Documentation: document HFSPlus 2007-07-31 15:39:38 -07:00
hpfs.txt
inotify.txt
isofs.txt
jfs.txt
Locking fs: introduce write_begin, write_end, and perform_write aops 2007-10-16 09:42:55 -07:00
locks.txt Documentation: move locks.txt in filesystems/ 2007-10-09 18:32:45 -04:00
mandatory-locking.txt locks: add warning about mandatory locking races 2007-10-09 18:32:45 -04:00
ncpfs.txt
ntfs.txt NTFS: Fix a mount time deadlock. 2007-10-12 09:16:30 -07:00
ocfs2.txt ocfs2: update docs for new features 2007-09-11 11:38:25 -07:00
porting
proc.txt
quota.txt quota: send messages via netlink 2007-10-17 08:42:56 -07:00
ramfs-rootfs-initramfs.txt docs: ramdisk/initrd/initramfs corrections 2007-10-17 08:42:56 -07:00
relay.txt
romfs.txt
smbfs.txt
spufs.txt
sysfs-pci.txt
sysfs.txt
sysv-fs.txt
tmpfs.txt
udf.txt
ufs.txt
vfat.txt
vfs.txt fs: remove some AOP_TRUNCATED_PAGE 2007-10-16 09:42:58 -07:00
xfs.txt
xip.txt