linux/fs
Eric Paris b09e0fa4b4 tmpfs: implement generic xattr support
Implement generic xattrs for tmpfs filesystems.  The Feodra project, while
trying to replace suid apps with file capabilities, realized that tmpfs,
which is used on the build systems, does not support file capabilities and
thus cannot be used to build packages which use file capabilities.  Xattrs
are also needed for overlayfs.

The xattr interface is a bit odd.  If a filesystem does not implement any
{get,set,list}xattr functions the VFS will call into some random LSM hooks
and the running LSM can then implement some method for handling xattrs.
SELinux for example provides a method to support security.selinux but no
other security.* xattrs.

As it stands today when one enables CONFIG_TMPFS_POSIX_ACL tmpfs will have
xattr handler routines specifically to handle acls.  Because of this tmpfs
would loose the VFS/LSM helpers to support the running LSM.  To make up
for that tmpfs had stub functions that did nothing but call into the LSM
hooks which implement the helpers.

This new patch does not use the LSM fallback functions and instead just
implements a native get/set/list xattr feature for the full security.* and
trusted.* namespace like a normal filesystem.  This means that tmpfs can
now support both security.selinux and security.capability, which was not
previously possible.

The basic implementation is that I attach a:

struct shmem_xattr {
	struct list_head list; /* anchored by shmem_inode_info->xattr_list */
	char *name;
	size_t size;
	char value[0];
};

Into the struct shmem_inode_info for each xattr that is set.  This
implementation could easily support the user.* namespace as well, except
some care needs to be taken to prevent large amounts of unswappable memory
being allocated for unprivileged users.

[mszeredi@suse.cz: new config option, suport trusted.*, support symlinks]
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Hugh Dickins <hughd@google.com>
Tested-by: Jordi Pujol <jordipujolp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:31 -07:00
..
9p fs/9p: Fix error reported by coccicheck 2011-04-15 15:26:14 -05:00
adfs Fix common misspellings 2011-03-31 11:26:23 -03:00
affs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
afs Fix common misspellings 2011-03-31 11:26:23 -03:00
autofs4 Fix common misspellings 2011-03-31 11:26:23 -03:00
befs Fix common misspellings 2011-03-31 11:26:23 -03:00
bfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
cachefiles Fix common misspellings 2011-03-31 11:26:23 -03:00
ceph ceph: do not use i_wrbuffer_ref as refcount for Fb cap 2011-05-11 10:44:48 -07:00
cifs [CIFS] Fix to problem with getattr caused by invalidate simplification patch 2011-05-20 17:00:01 +00:00
coda codafs: fix build break when CONFIG_PROC_SYSCTL=n 2011-03-25 17:45:16 -07:00
configfs configfs: Fix race between configfs_readdir() and configfs_d_iput() 2011-05-18 04:08:16 -07:00
cramfs cramfs: generate unique inode number for better inode cache usage 2011-01-13 08:03:23 -08:00
debugfs debugfs: move to new strtobool 2011-05-19 16:55:28 +09:30
devpts fs/devpts/inode.c: correctly check d_alloc_name() return code in devpts_pty_new() 2011-03-22 17:44:17 -07:00
dlm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm 2011-05-24 15:04:00 -07:00
ecryptfs eCryptfs: Flush dirty pages in setattr 2011-04-25 18:49:46 -05:00
efs block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
exofs Fix common misspellings 2011-03-31 11:26:23 -03:00
exportfs vfs: Add open by file handle support 2011-03-15 02:21:44 -04:00
ext2 ext2: fix error msg when mounting fs with too-large blocksize 2011-05-17 13:47:42 +02:00
ext3 ext3: Fix fs corruption when make_indexed_dir() fails 2011-05-17 13:47:15 +02:00
ext4 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2011-04-11 15:45:47 -07:00
fat fat: Fix statfs->f_namelen 2011-04-12 21:12:50 +09:00
freevxfs treewide: fix a few typos in comments 2011-05-10 10:16:21 +02:00
fscache FS-Cache: Fix operation handling 2011-01-14 09:23:36 -08:00
fuse fuse: fix oops in revalidate when called with NULL nameidata 2011-05-10 17:35:58 +02:00
gfs2 vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
hfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
hfsplus Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
hostfs switch hostfs 2011-01-12 20:03:42 -05:00
hpfs HPFS: Remove unused variable 2011-05-09 09:04:24 -07:00
hppfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hugetlbfs mm: Convert i_mmap_lock to a mutex 2011-05-25 08:39:18 -07:00
isofs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
jbd jbd: Fix comment to match the code in journal_start() 2011-05-24 00:27:53 +02:00
jbd2 jbd/jbd2: remove obsolete summarise_journal_usage. 2011-05-17 13:47:42 +02:00
jffs2 Fix common misspellings 2011-03-31 11:26:23 -03:00
jfs Fix common misspellings 2011-03-31 11:26:23 -03:00
lockd NLM: Fix "kernel BUG at fs/lockd/host.c:417!" or ".../host.c:283!" 2011-01-25 15:24:47 -05:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
minix Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ncpfs Fix common misspellings 2011-03-31 11:26:23 -03:00
nfs vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
nfs_common Fix common misspellings 2011-03-31 11:26:23 -03:00
nfsd treewide: fix a few typos in comments 2011-05-10 10:16:21 +02:00
nilfs2 nilfs2: use mark_buffer_dirty to mark btnode or meta data dirty 2011-05-10 22:21:57 +09:00
nls
notify Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
ntfs Fix common misspellings 2011-03-31 11:26:23 -03:00
ocfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
omfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
openpromfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
partitions Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
proc Don't lock guardpage if the stack is growing up 2011-05-09 16:22:07 -07:00
pstore pstore: fix pstore filesystem mount/remount issue 2011-05-16 11:05:00 -07:00
qnx4 block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
quota vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
ramfs ramfs: fix memleak on no-mmu arch 2011-04-14 16:06:56 -07:00
reiserfs Fix common misspellings 2011-03-31 11:26:23 -03:00
romfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
squashfs treewide: fix a few typos in comments 2011-05-10 10:16:21 +02:00
sysfs sysfs: remove "last sysfs file:" line from the oops messages 2011-05-13 16:05:51 -07:00
sysv Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ubifs UBIFS: switch to dynamic printks 2011-05-23 08:22:20 +03:00
udf Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ufs Merge branch 'master' into for-next 2011-04-26 10:22:59 +02:00
xfs vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
aio.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
anon_inodes.c sanitize vfsmount refcounting changes 2011-01-16 13:47:07 -05:00
attr.c Fix common misspellings 2011-03-31 11:26:23 -03:00
bad_inode.c fs: provide rcu-walk aware permission i_ops 2011-01-07 17:50:29 +11:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c brk: COMPAT_BRK: fix detection of randomized brk 2011-04-14 16:06:55 -07:00
binfmt_em86.c
binfmt_flat.c CRED: Fix load_flat_shared_library() to initialise bprm correctly 2011-05-03 10:10:51 +10:00
binfmt_misc.c convert get_sb_single() users 2010-10-29 04:16:28 -04:00
binfmt_script.c
binfmt_som.c
bio-integrity.c block: Require subsystems to explicitly allocate bio_set integrity mempool 2011-03-17 11:11:05 +01:00
bio.c Fix common misspellings 2011-03-31 11:26:23 -03:00
block_dev.c block: move bd_set_size() above rescan_partitions() in __blkdev_get() 2011-05-23 08:50:48 -07:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-24 19:01:30 -07:00
char_dev.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 2011-01-07 14:39:20 -08:00
compat.c exec: unify do_execve/compat_do_execve code 2011-04-09 15:53:56 +02:00
dcache.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
dcookies.c
direct-io.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
drop_caches.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
eventfd.c Docbook: add fs/eventfd.c and fix typos in it 2011-02-21 15:07:04 -08:00
eventpoll.c Fix common misspellings 2011-03-31 11:26:23 -03:00
exec.c mm: mmu_gather rework 2011-05-25 08:39:12 -07:00
fcntl.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
fhandle.c fs/fhandle.c: add <linux/personality.h> for ia64 2011-04-14 16:06:56 -07:00
fifo.c Filesystem: fifo: Fixed coding style issue. 2011-03-21 00:16:09 -04:00
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-16 13:26:17 -07:00
file.c vfs: avoid large kmalloc()s for the fdtable 2011-04-28 11:28:20 -07:00
filesystems.c fs: synchronize_rcu when unregister_filesystem success not failure 2011-04-17 10:42:01 -07:00
fs_struct.c sanitize vfsmount refcounting changes 2011-01-16 13:47:07 -05:00
fs-writeback.c Fix common misspellings 2011-03-31 11:26:23 -03:00
generic_acl.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
inode.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
internal.h fs: move i_wb_list out from under inode_lock 2011-03-24 21:17:51 -04:00
ioctl.c vfs: cleanup do_vfs_ioctl() 2011-03-21 00:16:08 -04:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig tmpfs: implement generic xattr support 2011-05-25 08:39:31 -07:00
Kconfig.binfmt coredump: default CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS=y 2010-10-27 18:03:12 -07:00
libfs.c pass default dentry_operations to mount_pseudo() 2011-01-12 20:03:43 -05:00
locks.c Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linux 2011-03-24 08:20:39 -07:00
Makefile Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2011-03-16 19:01:29 -07:00
mbcache.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
mpage.c fs: make mpage read/write_pages() plug 2011-03-10 08:52:26 +01:00
namei.c VFS: move BUG_ON test for symlink nd->depth after current->link_count test 2011-05-21 00:12:16 -07:00
namespace.c Revert "vfs: Export file system uuid via /proc/<pid>/mountinfo" 2011-04-12 13:35:56 -07:00
nfsctl.c open-style analog of vfs_path_lookup() 2011-03-14 09:15:28 -04:00
no-block.c
open.c fs: Use BUG_ON(!mnt) at dentry_open(). 2011-03-21 01:10:41 -04:00
pipe.c Fix broken "pipe: use event aware wakeups" optimization 2011-01-20 16:21:59 -08:00
pnode.c fs: scale mntget/mntput 2011-01-07 17:50:33 +11:00
pnode.h
posix_acl.c NFS: Prevent memory allocation failure in nfsacl_encode() 2011-01-25 15:24:47 -05:00
read_write.c fix signedness mess in rw_verify_area() on 64bit architectures 2011-01-12 20:06:58 -05:00
read_write.h
readdir.c
select.c select: remove unused MAX_SELECT_SECONDS 2011-03-21 00:16:08 -04:00
seq_file.c
signalfd.c
splice.c Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
stack.c
stat.c readlinkat(), fchownat() and fstatat() with empty relative pathnames 2011-03-15 02:21:45 -04:00
statfs.c clean statfs-like syscalls up 2011-03-14 09:15:28 -04:00
super.c VFS: trivial: fix comment on s_maxbytes value warning check 2011-05-19 14:10:49 +00:00
sync.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
timerfd.c timerfd: Manage cancelable timers in timerfd 2011-05-23 13:59:53 +02:00
utimes.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
xattr_acl.c
xattr.c vfs: Pass setxattr(2) flags properly 2011-04-21 07:34:44 -07:00