android_kernel_xiaomi_sdm845/fs
Eric W. Biederman 3ff195b011 sysfs: Implement sysfs tagged directory support.
The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
..
9p 9p: add bdi backing to mount session 2010-04-22 11:42:00 +02:00
adfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
affs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
afs Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2010-04-28 07:56:05 -07:00
autofs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
autofs4 autofs4-2.6.34-rc1 - fix link_count usage 2010-05-10 09:48:10 -07:00
befs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bfs pass writeback_control to ->write_inode 2010-03-05 13:25:52 -05:00
btrfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2010-05-15 12:55:31 -07:00
cachefiles CacheFiles: Fix error handling in cachefiles_determine_cache_security() 2010-05-12 18:23:58 -07:00
ceph ceph: preserve seq # on requeued messages after transient transport errors 2010-05-11 21:20:38 -07:00
cifs cifs: fix noserverino handling when unix extensions are enabled 2010-05-17 20:59:21 +00:00
coda coda: add bdi backing to mount session 2010-04-22 12:12:40 +02:00
configfs Fix the regression created by "set S_DEAD on unlink()..." commit 2010-05-15 07:16:33 -04:00
cramfs
debugfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
devpts include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dlm dlm: fix ast ordering for user locks 2010-04-30 14:52:51 -05:00
ecryptfs ecryptfs: add bdi backing to mount session 2010-04-22 12:22:04 +02:00
efs
exofs exofs: Fix "add bdi backing to mount session" fall out 2010-04-29 20:35:29 +02:00
exportfs
ext2 ext2: symlink must be handled via filesystem specific operation 2010-04-12 21:11:25 +02:00
ext3 ext3: symlink must be handled via filesystem specific operation 2010-04-12 21:11:39 +02:00
ext4 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2010-04-25 10:01:51 -07:00
fat Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
freevxfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fscache fs-cache: order the debugfs stats correctly 2010-04-07 08:38:05 -07:00
fuse include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw 2010-05-21 07:29:15 -07:00
hfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hfsplus include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hostfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hpfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hppfs hppfs can use existing proc_mnt, no need for do_kern_mount() in there 2010-03-03 14:08:00 -05:00
hugetlbfs Untangling ima mess, part 1: alloc_file() 2009-12-16 12:16:47 -05:00
isofs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
jbd include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
jbd2 jbd2: use NULL instead of 0 when pointer is needed 2010-05-11 10:04:36 +02:00
jffs2 jffs2: Stop triggering block erases from jffs2_write_super() 2010-05-19 17:16:11 +01:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-05-20 09:20:59 -07:00
lockd include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-05-20 09:20:59 -07:00
minix include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ncpfs ncpfs: add bdi backing to mount session 2010-04-22 12:31:11 +02:00
nfs NFS: Don't call iput() in nfs_access_cache_shrinker 2010-05-14 15:09:36 -04:00
nfs_common include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nfsd Revert "nfsd4: distinguish expired from stale stateids" 2010-05-18 19:03:50 -04:00
nilfs2 nilfs2: disallow remount of snapshot from/to a regular mount 2010-05-10 11:32:34 +09:00
nls
notify Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-05-14 11:49:42 -07:00
ntfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ocfs2 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 2010-05-21 07:20:17 -07:00
omfs Merge branch 'master' into for-next 2010-04-23 02:08:44 +02:00
openpromfs
partitions include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
proc Merge branch 'bkl/procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-05-19 17:23:28 -07:00
qnx4 fs/qnx4: decrement sizeof size in strncmp 2010-02-04 11:55:46 +01:00
quota quota: Convert __DQUOT_PARANOIA symbol to standard config option 2010-04-20 18:25:25 +02:00
ramfs devtmpfs: support !CONFIG_TMPFS 2010-05-21 09:37:30 -07:00
reiserfs reiserfs: fix corruption during shrinking of xattrs 2010-04-24 11:31:24 -07:00
romfs fix leak in romfs_fill_super() 2010-01-26 22:22:26 -05:00
smbfs smbfs: add bdi backing to mount session 2010-04-22 12:37:07 +02:00
squashfs squashfs: fix potential buffer over-run on 4K block file systems 2010-04-25 02:09:05 +01:00
sysfs sysfs: Implement sysfs tagged directory support. 2010-05-21 09:37:31 -07:00
sysv fs/sysv: dereferencing ERR_PTR() 2010-05-15 07:16:33 -04:00
ubifs UBIFS: mark VFS SB RO too 2010-04-29 15:12:18 +03:00
udf udf: add speciffic ->setattr callback 2010-04-08 15:35:20 +02:00
ufs ufs: make solaris fsck happy 2010-03-12 15:52:35 -08:00
xfs xfs: mark xfs_iomap_write_ helpers static 2010-05-19 09:58:20 -05:00
aio.c aio: remove unused field 2009-12-16 07:20:13 -08:00
anon_inodes.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
attr.c fs: use rlimit helpers 2010-03-06 11:26:29 -08:00
bad_inode.c
binfmt_aout.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_elf_fdpic.c Remove redundant check for CONFIG_MMU 2010-04-27 09:01:26 -07:00
binfmt_elf.c coredump: pass mm->flags as a coredump parameter for consistency 2010-03-06 11:26:46 -08:00
binfmt_em86.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_flat.c uclinux: error message when FLAT reloc symbol is invalid, v2 2010-04-21 13:28:49 +10:00
binfmt_misc.c
binfmt_script.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_som.c Split 'flush_old_exec' into two functions 2010-01-29 08:22:01 -08:00
bio-integrity.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bio.c Merge branch 'master' into for-linus 2010-03-19 08:05:10 +01:00
block_dev.c fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to block devices 2010-04-24 11:31:26 -07:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
char_dev.c
compat_binfmt_elf.c elf coredump: replace ELF_CORE_EXTRA_* macros by functions 2010-03-06 11:26:45 -08:00
compat_ioctl.c pktcdvd: improve BKL and compat_ioctl.c usage 2010-04-29 08:44:37 -07:00
compat.c revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
dcache.c fix race in d_splice_alias() 2010-03-03 14:13:08 -05:00
dcookies.c
direct-io.c dio: fix use-after-free 2009-12-17 04:52:13 -05:00
drop_caches.c
eventfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
eventpoll.c sched, wait: Use wrapper functions 2010-05-11 17:43:58 +02:00
exec.c revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
fcntl.c fasync: RCU and fine grained locking 2010-04-21 16:19:29 -07:00
fifo.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
file_table.c vfs: take f_lock on modifying f_mode after open time 2010-03-06 11:26:25 -08:00
file.c fs: use rlimit helpers 2010-03-06 11:26:29 -08:00
filesystems.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fs_struct.c
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2010-04-09 11:50:29 -07:00
generic_acl.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
inode.c security: remove dead hook inode_delete 2010-04-12 12:19:15 +10:00
internal.h Take vfsmount_lock to fs/internal.h 2010-03-03 14:07:59 -05:00
ioctl.c Cleanup generic block based fiemap 2010-04-23 10:39:48 -07:00
ioprio.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-03-19 09:43:06 -07:00
Kconfig.binfmt
libfs.c FS / libfs: Implement simple_write_to_buffer 2010-05-10 23:08:17 +02:00
locks.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-03-19 09:43:06 -07:00
mbcache.c
mpage.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
namei.c Fix the regression created by "set S_DEAD on unlink()..." commit 2010-05-15 07:16:33 -04:00
namespace.c Merge branch 'next' into for-linus 2010-05-18 08:57:00 +10:00
nfsctl.c Switch may_open() and break_lease() to passing O_... 2010-03-03 13:00:21 -05:00
no-block.c
open.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pipe.c fs: no games with DCACHE_UNHASHED 2009-12-17 10:51:40 -05:00
pnode.c Kill CL_PROPAGATION, sanitize fs/pnode.c:get_source() 2010-03-03 13:00:22 -05:00
pnode.h VFS: Clean up shared mount flag propagation 2010-03-03 14:07:55 -05:00
posix_acl.c
read_write.c do_sync_read/write() should set kiocb.ki_nbytes to be consistent 2010-03-24 16:43:29 -07:00
read_write.h
readdir.c
select.c Add generic sys_old_select() 2010-03-12 15:52:32 -08:00
seq_file.c seq_file: fix new kernel-doc warnings 2010-03-07 15:48:26 -08:00
signalfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
splice.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
stack.c VFS/fsstack: handle 32-bit smp + preempt + large files in fsstack_copy_inode_size 2009-12-17 10:58:17 -05:00
stat.c Add unlocked version of inode_add_bytes() function 2009-12-23 13:33:54 +01:00
super.c fs: fs/super.c needs to include backing-dev.h for !CONFIG_BLOCK 2010-04-29 20:33:35 +02:00
sync.c Catch filesystems lacking s_bdi 2010-04-25 08:54:42 +02:00
timerfd.c fs/timerfd.c: make use of wait_event_interruptible_locked_irq() 2010-05-20 13:21:42 -07:00
utimes.c
xattr_acl.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
xattr.c sanitize xattr handler prototypes 2009-12-16 12:16:49 -05:00