android_kernel_xiaomi_sm7250/fs
Sukadev Bhattiprolu 1f8f1e2965 Define mknod_ptmx()
/dev/ptmx is closely tied to the devpts filesystem. An open of /dev/ptmx,
allocates the next pty index and the associated device shows up in the
devpts fs as /dev/pts/n.

Wih multiple instancs of devpts filesystem, during an open of /dev/ptmx
we would be unable to determine which instance of the devpts is being
accessed.

So we move the 'ptmx' node into /dev/pts and use the inode of the 'ptmx'
node to identify the superblock and hence the devpts instance.  This patch
adds ability for the kernel to internally create the [ptmx, c, 5:2] device
when mounting devpts filesystem.  Since the ptmx node in devpts is new and
may surprise some userspace scripts, the default permissions for the new
node is 0000.  These permissions can be changed either using chmod or by
remounting with the new '-o ptmxmode=0666' mount option.

Changelog[v5]:
	- [Serge Hallyn bugfix]: Letting new_inode() assign inode number to
	  ptmx can collide with hand-assigning inode numbers to ptys. So,
	  hand-assign specific inode number to ptmx node also.
	- [Serge Hallyn]: Maybe safer to grab root dentry mutex while creating
	  ptmx node
	- [Bugfix with Serge Hallyn] Replace lookup_one_len() in mknod_ptmx()
	  wih d_alloc_name() (lookup during ->get_sb() locks up system). To
	  simplify patchset, fold the ptmx_dentry patch into this.

Changelog[v4]:
	- Change default permissions of pts/ptmx node to 0000.
	- Move code for ptmxmode under #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES.

Changelog[v3]:
	- Rename ptmx_mode to ptmxmode (for consistency with 'newinstance')

Changelog[v2]:
	- [H. Peter Anvin] Remove mknod() system call support and create the
	  ptmx node internally.

Changelog[v1]:
	- Earlier version of this patch enabled creating /dev/pts/tty as
	  well. As pointed out by Al Viro and H. Peter Anvin, that is not
	  really necessary.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:36 -08:00
..
9p Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
adfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
affs CRED: Wrap task credential accesses in the AFFS filesystem 2008-11-14 10:38:45 +11:00
afs fs: replace NIPQUAD() 2008-10-31 00:56:28 -07:00
autofs CRED: Wrap task credential accesses in the autofs filesystem 2008-11-14 10:38:45 +11:00
autofs4 Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
befs befs: ensure fast symlinks are NUL-terminated 2008-12-31 18:07:40 -05:00
bfs CRED: Wrap task credential accesses in the BFS filesystem 2008-11-14 10:38:47 +11:00
cifs kill ->dir_notify() 2008-12-31 18:07:43 -05:00
coda coda: fix creds reference 2008-11-20 08:11:52 +11:00
configfs [PATCH] assorted path_lookup() -> kern_path() conversions 2008-10-23 05:12:52 -04:00
cramfs cramfs: fix named-pipe handling 2008-08-20 15:40:32 -07:00
debugfs integrity: special fs magic 2008-10-13 09:47:43 +11:00
devpts Define mknod_ptmx() 2009-01-02 10:19:36 -08:00
dlm fix warning in fs/dlm/netlink.c 2008-11-25 16:51:45 -08:00
ecryptfs eCryptfs: check readlink result was not an error before using it 2008-12-31 18:07:38 -05:00
efs [PATCH] switch all filesystems over to d_obtain_alias 2008-10-23 05:13:01 -04:00
exportfs Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
ext2 nfsd race fixes: ext2 2008-12-31 18:07:43 -05:00
ext3 nfsd race fixes: ext3 2008-12-31 18:07:44 -05:00
ext4 nfsd race fixes: ext4 2008-12-31 18:07:44 -05:00
fat Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2008-12-30 20:33:34 -08:00
freevxfs freevxfs: ensure fast symlinks are NUL-terminated 2008-12-31 18:07:40 -05:00
fuse CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
gfs2 CRED: Wrap task credential accesses in the GFS2 filesystem 2008-11-14 10:38:53 +11:00
hfs CRED: Wrap task credential accesses in the HFS filesystem 2008-11-14 10:38:54 +11:00
hfsplus CRED: Wrap task credential accesses in the HFSplus filesystem 2008-11-14 10:38:54 +11:00
hostfs hostfs: fix a duplicated global function name 2008-11-19 18:50:00 -08:00
hpfs CRED: Wrap task credential accesses in the HPFS filesystem 2008-11-14 10:38:55 +11:00
hppfs CRED: Use creds in file structs 2008-11-14 10:39:25 +11:00
hugetlbfs CRED: Wrap current->cred and a few other accessors 2008-11-14 10:39:18 +11:00
isofs [PATCH] switch all filesystems over to d_obtain_alias 2008-10-23 05:13:01 -04:00
jbd jbd: don't give up looking for space so easily in __log_wait_for_space 2008-11-06 22:37:59 -05:00
jbd2 jbd2: don't give up looking for space so easily in __jbd2_log_wait_for_space 2008-11-06 22:38:07 -05:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2008-11-06 15:43:13 -08:00
jfs nfsd race fixes: jfs 2008-12-31 18:07:44 -05:00
lockd Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
minix CRED: Wrap task credential accesses in the Minix filesystem 2008-11-14 10:38:57 +11:00
ncpfs CRED: Wrap task credential accesses in the NCPFS filesystem 2008-11-14 10:38:58 +11:00
nfs Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
nfs_common SUNRPC: nfsacl_encode/nfsacl_decode should be exported as GPL-only 2008-12-23 15:21:32 -05:00
nfsd Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
nls remove CONFIG_KMOD from fs 2008-10-17 02:38:36 +11:00
notify filesystem notification: create fs/notify to contain all fs notification 2008-12-31 18:07:43 -05:00
ntfs ntfs: don't fool kernel-doc 2008-12-01 19:55:25 -08:00
ocfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
omfs CRED: Wrap task credential accesses in the OMFS filesystem 2008-11-14 10:38:59 +11:00
openpromfs [PATCH] fix ->llseek for more directories 2008-10-23 05:13:21 -04:00
partitions block/md: fix md autodetection 2008-11-18 15:08:56 +01:00
proc Merge branch 'irq-fixes-for-linus-4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-31 09:00:59 -08:00
qnx4
ramfs CRED: Wrap task credential accesses in the RAMFS filesystem 2008-11-14 10:39:00 +11:00
reiserfs nfsd race fixes: reiserfs 2008-12-31 18:07:44 -05:00
romfs
smbfs CRED: Wrap current->cred and a few other accessors 2008-11-14 10:39:18 +11:00
sysfs [PATCH] fix ->llseek for more directories 2008-10-23 05:13:21 -04:00
sysv sysv: ensure fast symlinks are NUL-terminated 2008-12-31 18:07:39 -05:00
ubifs Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
udf Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
ufs CRED: Wrap task credential accesses in the UFS filesystem 2008-11-14 10:39:04 +11:00
xfs [XFS] Fix merge failures 2008-12-29 16:47:18 +11:00
aio.c aio: make the lookup_ioctx() lockless 2008-12-29 08:29:50 +01:00
anon_inodes.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
attr.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
bad_inode.c kill ->dir_notify() 2008-12-31 18:07:43 -05:00
binfmt_aout.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_elf_fdpic.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_elf.c Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2008-12-28 12:33:21 -08:00
binfmt_em86.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_flat.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_misc.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_script.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_som.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
bio-integrity.c bio: allow individual slabs in the bio_set 2008-12-29 08:29:23 +01:00
bio.c bio: get rid of bio_vec clearing 2008-12-29 08:29:53 +01:00
block_dev.c fs/block_dev.c: __read_mostly improvement and sb_is_blkdev_sb utilization 2008-12-31 18:07:43 -05:00
buffer.c block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set 2008-12-29 08:28:44 +01:00
char_dev.c [PATCH] tidy up chrdev_open 2008-10-23 05:12:59 -04:00
compat_binfmt_elf.c
compat_ioctl.c
compat.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
dcache.c filp_cachep can be static in fs/file_table.c 2008-12-31 18:07:42 -05:00
dcookies.c shrink struct dentry 2008-12-31 18:07:38 -05:00
direct-io.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
dquot.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
drop_caches.c
eventfd.c
eventpoll.c epoll: introduce resource usage limits 2008-12-01 19:55:24 -08:00
exec.c kill vfs_permission 2008-12-31 18:07:41 -05:00
fcntl.c Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
fifo.c [PATCH] introduce fmode_t, do annotations 2008-10-21 07:47:06 -04:00
file_table.c filp_cachep can be static in fs/file_table.c 2008-12-31 18:07:42 -05:00
file.c
filesystems.c proc: move /proc/filesystems to fs/filesystems.c 2008-10-23 14:27:09 +04:00
fs-writeback.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
generic_acl.c
inode.c nfsd/create race fixes, infrastructure 2008-12-31 18:07:43 -05:00
internal.h CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
ioctl.c Fix a race condition in FASYNC handling 2008-12-05 15:35:10 -08:00
ioprio.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
Kconfig filesystem notification: create fs/notify to contain all fs notification 2008-12-31 18:07:43 -05:00
Kconfig.binfmt add CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS 2008-10-20 08:52:39 -07:00
libfs.c fs: remove prepare_write/commit_write 2008-10-30 11:38:45 -07:00
locks.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
Makefile filesystem notification: create fs/notify to contain all fs notification 2008-12-31 18:07:43 -05:00
mbcache.c
mpage.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
namei.c make INIT_FS use the __RW_LOCK_UNLOCKED initialization 2008-12-31 18:07:42 -05:00
namespace.c fs/namespace.c: drop code after return 2008-12-31 18:07:38 -05:00
nfsctl.c pass a struct path * to may_open 2008-12-31 18:07:41 -05:00
no-block.c
open.c introduce new LSM hooks where vfsmount is available. 2008-12-31 18:07:37 -05:00
pipe.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
pnode.c
pnode.h
posix_acl.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
quota_v1.c
quota_v2.c
quota.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
read_write.c [PATCH] generic_file_llseek tidyups 2008-10-23 05:12:59 -04:00
read_write.h
readdir.c [PATCH] prepare vfs_readdir() callers to returning filldir result 2008-10-23 05:13:10 -04:00
select.c select: deal with math overflow from borderline valid userland data 2008-10-26 11:22:08 -07:00
seq_file.c expand some comments (d_path / seq_path) 2008-12-31 18:07:41 -05:00
signalfd.c
splice.c fs: remove prepare_write/commit_write 2008-10-30 11:38:45 -07:00
stack.c
stat.c
super.c security: pass mount flags to security_sb_kern_mount() 2008-12-20 09:02:39 +11:00
sync.c
timerfd.c hrtimer: convert timerfd to the new hrtimer apis 2008-09-05 21:35:09 -07:00
utimes.c
xattr_acl.c
xattr.c