sst-linux/fs
Tejun Heo ae34372eb8 kernfs: remove KERNFS_REMOVED
KERNFS_REMOVED is used to mark half-initialized and dying nodes so
that they don't show up in lookups and deny adding new nodes under or
renaming it; however, its role overlaps those of deactivation and
removal from rbtree.

It's necessary to deny addition of new children while removal is in
progress; however, this role considerably intersects with deactivation
- KERNFS_REMOVED prevents new children while deactivation prevents new
file operations.  There's no reason to have them separate making
things more complex than necessary.

KERNFS_REMOVED is also used to decide whether a node is still visible
to vfs layer, which is rather redundant as equivalent determination
can be made by testing whether the node is on its parent's children
rbtree or not.

This patch removes KERNFS_REMOVED.

* Instead of KERNFS_REMOVED, each node now starts its life
  deactivated.  This means that we now use both atomic_add() and
  atomic_sub() on KN_DEACTIVATED_BIAS, which is INT_MIN.  The compiler
  generates an overflow warnings when negating INT_MIN as the negation
  can't be represented as a positive number.  Nothing is actually
  broken but let's bump BIAS by one to avoid the warnings for archs
  which negates the subtrahend..

* KERNFS_REMOVED tests in add and rename paths are replaced with
  kernfs_get/put_active() of the target nodes.  Due to the way the add
  path is structured now, active ref handling is done in the callers
  of kernfs_add_one().  This will be consolidated up later.

* kernfs_remove_one() is updated to deactivate instead of setting
  KERNFS_REMOVED.  This removes deactivation from kernfs_deactivate(),
  which is now renamed to kernfs_drain().

* kernfs_dop_revalidate() now tests RB_EMPTY_NODE(&kn->rb) instead of
  KERNFS_REMOVED and KERNFS_REMOVED test in kernfs_dir_pos() is
  dropped.  A node which is removed from the children rbtree is not
  included in the iteration in the first place.  This means that a
  node may be visible through vfs a bit longer - it's now also visible
  after deactivation until the actual removal.  This slightly enlarged
  window difference doesn't make any difference to the userland.

* Sanity check on KERNFS_REMOVED in kernfs_put() is replaced with
  checks on the active ref.

* Some comment style updates in the affected area.

v2: Reordered before removal path restructuring.  kernfs_active()
    dropped and kernfs_get/put_active() used instead.  RB_EMPTY_NODE()
    used in the lookup paths.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10 13:44:25 -08:00
..
9p consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs remove obsolete references to powertweak 2013-11-27 20:34:32 -08:00
afs Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next 2013-10-28 19:36:46 -04:00
autofs4 autofs4: make freeing sbi rcu-delayed 2013-10-24 23:43:27 -04:00
befs befs: split symlink iops in two - for short and long symlinks resp. 2013-10-24 23:34:50 -04:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2013-12-12 15:25:10 -08:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
ceph ceph: Avoid data inconsistency due to d-cache aliasing in readpage() 2013-12-13 09:11:38 -08:00
cifs [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload 2013-11-25 09:50:31 -06:00
coda coda_revalidate_inode(): switch to passing inode... 2013-11-09 00:16:21 -05:00
configfs configfs: fix race between dentry put and lookup 2013-11-21 16:42:27 -08:00
cramfs cramfs: mark as obsolete 2013-11-13 12:09:12 +09:00
debugfs debugfs: use list_next_entry() in debugfs_remove_recursive() 2013-11-13 12:09:24 +09:00
devpts devpts: plug the memory leak in kill_sb 2013-11-13 12:09:36 +09:00
dlm genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
ecryptfs Quiet static checkers by removing unneeded conditionals 2013-11-22 10:58:14 -08:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs efs: iget_locked() doesn't return an ERR_PTR() 2013-08-24 12:10:22 -04:00
exofs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2: Fix fs corruption in ext2_get_xip_mem() 2013-11-05 11:26:47 +01:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-11-13 15:25:47 +09:00
ext4 Ext4 updates for 3.13. Mostly bug fixes and cleanups. 2013-11-14 17:19:58 +09:00
f2fs f2fs: issue more large discard command 2013-11-11 09:36:32 +09:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs [readdir] convert freevxfs 2013-06-29 12:56:53 +04:00
fscache Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
gfs2 GFS2: Fix ref count bug relating to atomic_open 2013-11-21 18:47:57 +00:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
hostfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
hpfs locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
hppfs clean up scary strncpy(dst, src, strlen(src)) uses 2013-07-03 16:07:41 -07:00
hugetlbfs cope with potentially long ->d_dname() output for shmem/hugetlb 2013-08-24 12:10:17 -04:00
isofs isofs: don't pass dentry to isofs_hash{i,}_common() 2013-10-24 23:34:59 -04:00
jbd jbd: Revert "jbd: remove dependency on __GFP_NOFAIL" 2013-10-31 20:37:15 +01:00
jbd2 jbd2: Fix endian mixing problems in the checksumming code 2013-08-28 14:59:58 -04:00
jffs2 jffs2: do not support the MLC nand 2013-10-27 16:27:07 -07:00
jfs Just a patch to fix an oops in an error path. 2013-10-22 09:01:11 +01:00
kernfs kernfs: remove KERNFS_REMOVED 2014-01-10 13:44:25 -08:00
lockd LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs 2013-08-05 15:03:46 -04:00
logfs block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
minix fs/minix: Drop dependency on H8300 2013-09-16 18:20:25 -07:00
ncpfs ncpfs: rcu-delay unload_nls() and freeing ncp_server 2013-10-24 23:43:28 -04:00
nfs NFS client bugfixes 2013-12-05 13:05:48 -08:00
nfs_common
nfsd nfsd: when reusing an existing repcache entry, unhash it first 2013-12-10 20:34:44 -05:00
nilfs2 nilfs2: fix issue with race condition of competition between segments for dirty blocks 2013-09-30 14:31:02 -07:00
nls
notify fsnotify: update comments concerning locking scheme 2013-07-09 10:33:20 -07:00
ntfs iget/iget5: don't bother with ->i_lock until we find a match 2013-11-09 00:16:31 -05:00
ocfs2 tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs [readdir] convert openpromfs 2013-06-29 12:56:32 +04:00
proc procfs: also fix proc_reg_get_unmapped_area() for !MMU case 2013-12-12 18:19:26 -08:00
pstore pstore: Don't allow high traffic options on fragile devices 2013-12-20 13:12:01 -08:00
qnx4 qnx4: i_sb is never NULL 2013-11-09 00:16:32 -05:00
qnx6 [readdir] convert qnx6 2013-06-29 12:56:39 +04:00
quota genetlink: make multicast groups const, prevent abuse 2013-11-19 16:39:06 -05:00
ramfs initmpfs: move rootfs code from fs/ramfs/ to init/ 2013-09-11 15:59:37 -07:00
reiserfs reiserfs: fix race with flush_used_journal_lists and flush_journal_list 2013-09-24 11:24:21 +02:00
romfs [readdir] convert romfs 2013-06-29 12:56:29 +04:00
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs kernfs: add kernfs_dir_ops 2013-12-17 08:59:15 -08:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
udf udf: fix for pathetic mount times in case of invalid file system 2013-10-18 22:39:07 +02:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs xfs: abort metadata writeback on permanent errors 2013-12-17 09:40:23 -06:00
aio.c Merge git://git.kvack.org/~bcrl/aio-next 2013-12-22 11:03:49 -08:00
anon_inodes.c ... and kill anon_inode_getfile_private() 2013-11-09 00:16:28 -05:00
attr.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
bad_inode.c [readdir] ->readdir() is gone 2013-06-29 12:57:04 +04:00
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf_fdpic.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_elf.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_em86.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-block 2013-09-22 15:00:11 -07:00
bio.c bio: fix argument of __bio_add_page() for max_sectors > 0xffff 2013-11-18 12:31:27 -07:00
block_dev.c a trivial writeback fix 2013-09-13 23:06:40 -04:00
buffer.c fs: buffer: move allocation failure loop into the allocator 2013-10-16 21:35:53 -07:00
char_dev.c Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
compat_binfmt_elf.c
compat_ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
compat.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
coredump.c dump_emit(): use __kernel_write(), not vfs_write() 2013-11-15 22:04:09 -05:00
coredump.h
dcache.c dcache: allow word-at-a-time name hashing with big-endian CPUs 2013-12-12 10:39:01 -08:00
dcookies.c
direct-io.c direct-io: Use return from cmpxchg to decide of assignment happened 2013-09-09 10:47:42 -07:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c
eventpoll.c epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled 2013-12-03 15:35:52 +01:00
exec.c Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
file.c
filesystems.c
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fs-writeback.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
generic_acl.c
inode.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
internal.h get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: missing unlock on error in generic_add_lease() 2013-11-13 07:30:53 -05:00
Makefile sysfs, kernfs: add skeletons for kernfs 2013-11-27 13:28:24 -08:00
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h RCU'd vfsmounts 2013-11-09 00:16:19 -05:00
mpage.c
namei.c dcache: allow word-at-a-time name hashing with big-endian CPUs 2013-12-12 10:39:01 -08:00
namespace.c sysfs, kernfs: prepare mount path for kernfs 2013-11-29 18:16:08 -08:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c vfs: fix subtle use-after-free of pipe_inode_info 2013-12-02 09:44:51 -08:00
pnode.c split __lookup_mnt() in two functions 2013-10-24 23:35:00 -04:00
pnode.h vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces 2013-08-26 18:42:15 -07:00
posix_acl.c
proc_namespace.c don't bother with vfsmount_lock in mounts_poll() 2013-10-24 23:34:59 -04:00
read_write.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
readdir.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
select.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
seq_file.c seq_file: always clear m->count when we free m->buf 2013-11-18 19:07:53 -08:00
signalfd.c
splice.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
stack.c
stat.c vfs: split out vfs_getattr_nosec 2013-11-09 00:16:31 -05:00
statfs.c vfs: allow O_PATH file descriptors for fstatfs() 2013-10-12 13:12:31 -07:00
super.c get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
sync.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr_acl.c
xattr.c