kernel_optimize_test/fs
Coly Li f598f82e20 romfs: use different way to generate fsid for BLOCK or MTD
Commit 8a59f5d252 ("fs/romfs: return f_fsid for statfs(2)") generates
a 64bit id from sb->s_bdev->bd_dev.  This is only correct when romfs is
defined with CONFIG_ROMFS_ON_BLOCK.  If romfs is only defined with
CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev
will triger an oops.

Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y,
both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined.
Therefore when calling huge_encode_dev() to generate a 64bit id, I use
the follow order to choose parameter,

- CONFIG_ROMFS_ON_BLOCK defined
  use sb->s_bdev->bd_dev
- CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined
  use sb->s_dev when,
- both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined
  leave id as 0

When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev
is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index,
otherwise sb->s_dev is 0.

This is a try-best effort to generate a uniq file system ID, if all the
above conditions are not meet, f_fsid of this romfs instance will be 0.
Generally only one romfs can be built on single MTD block device, this
method is enough to identify multiple romfs instances in a computer.

Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de
Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Nong Li <nongli1031@gmail.com>
Tested-by: Nong Li <nongli1031@gmail.com>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24 16:26:14 -08:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph ceph: fix bad endianness handling in parse_reply_info_extra 2017-01-18 17:58:45 +01:00
cifs
coda
configfs
cramfs
crypto
debugfs
devpts
dlm
ecryptfs
efivarfs
efs
exofs
exportfs
ext2 dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
ext4 dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
f2fs
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hugetlbfs
isofs
jbd2
jffs2
jfs
kernfs
lockd
minix
ncpfs
nfs
nfs_common
nfsd
nilfs2
nls
notify
ntfs
ocfs2
omfs
openpromfs
orangefs
overlayfs ovl: fix possible use after free on redirect dir lookup 2017-01-18 15:19:54 +01:00
proc proc: add a schedule point in proc_pid_readdir() 2017-01-24 16:26:14 -08:00
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs romfs: use different way to generate fsid for BLOCK or MTD 2017-01-24 16:26:14 -08:00
squashfs
sysfs
sysv
tracefs
ubifs ubifs: Fix journal replay wrt. xattr nodes 2017-01-17 14:35:58 +01:00
udf
ufs
xfs xfs: fix xfs_mode_to_ftype() prototype 2017-01-18 12:39:21 -08:00
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c coredump: Ensure proper size of sparse core files 2017-01-14 19:32:40 -05:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c
buffer.c
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c
coredump.c coredump: Ensure proper size of sparse core files 2017-01-14 19:32:40 -05:00
dax.c dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file_table.c
file.c
filesystems.c
fs_pin.c
fs_struct.c
fs-writeback.c
inode.c
internal.h
ioctl.c
iomap.c
Kconfig dax: fix build warnings with FS_DAX and !FS_IOMAP 2017-01-24 16:26:14 -08:00
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c
namespace.c
no-block.c
nsfs.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
userfaultfd.c userfaultfd: fix SIGBUS resulting from false rwsem wakeups 2017-01-24 16:26:14 -08:00
utimes.c
xattr.c