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
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9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph
cifs
coda
configfs
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debugfs
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exofs
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fat
freevxfs
fscache
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gfs2
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isofs
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aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
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
dax.c
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
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
utimes.c
xattr.c