linux/fs
Jan Kara 9052c7cf49 nfs: Fix bdi handling for cloned superblocks
In commit 0d3b12584972 "nfs: Convert to separately allocated bdi" I have
wrongly cloned bdi reference in nfs_clone_super(). Further inspection
has shown that originally the code was actually allocating a new bdi (in
->clone_server callback) which was later registered in
nfs_fs_mount_common() and used for sb->s_bdi in nfs_initialise_sb().
This could later result in bdi for the original superblock not getting
unregistered when that superblock got shutdown (as the cloned sb still
held bdi reference) and later when a new superblock was created under
the same anonymous device number, a clash in sysfs has happened on bdi
registration:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 10284 at /linux-next/fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x74
sysfs: cannot create duplicate filename '/devices/virtual/bdi/0:32'
Modules linked in: axp20x_usb_power gpio_axp209 nvmem_sunxi_sid sun4i_dma sun4i_ss virt_dma
CPU: 1 PID: 10284 Comm: mount.nfs Not tainted 4.11.0-rc4+ #14
Hardware name: Allwinner sun7i (A20) Family
[<c010f19c>] (unwind_backtrace) from [<c010bc74>] (show_stack+0x10/0x14)
[<c010bc74>] (show_stack) from [<c03c6e24>] (dump_stack+0x78/0x8c)
[<c03c6e24>] (dump_stack) from [<c0122200>] (__warn+0xe8/0x100)
[<c0122200>] (__warn) from [<c0122250>] (warn_slowpath_fmt+0x38/0x48)
[<c0122250>] (warn_slowpath_fmt) from [<c02ac178>] (sysfs_warn_dup+0x64/0x74)
[<c02ac178>] (sysfs_warn_dup) from [<c02ac254>] (sysfs_create_dir_ns+0x84/0x94)
[<c02ac254>] (sysfs_create_dir_ns) from [<c03c8b8c>] (kobject_add_internal+0x9c/0x2ec)
[<c03c8b8c>] (kobject_add_internal) from [<c03c8e24>] (kobject_add+0x48/0x98)
[<c03c8e24>] (kobject_add) from [<c048d75c>] (device_add+0xe4/0x5a0)
[<c048d75c>] (device_add) from [<c048ddb4>] (device_create_groups_vargs+0xac/0xbc)
[<c048ddb4>] (device_create_groups_vargs) from [<c048dde4>] (device_create_vargs+0x20/0x28)
[<c048dde4>] (device_create_vargs) from [<c02075c8>] (bdi_register_va+0x44/0xfc)
[<c02075c8>] (bdi_register_va) from [<c023d378>] (super_setup_bdi_name+0x48/0xa4)
[<c023d378>] (super_setup_bdi_name) from [<c0312ef4>] (nfs_fill_super+0x1a4/0x204)
[<c0312ef4>] (nfs_fill_super) from [<c03133f0>] (nfs_fs_mount_common+0x140/0x1e8)
[<c03133f0>] (nfs_fs_mount_common) from [<c03335cc>] (nfs4_remote_mount+0x50/0x58)
[<c03335cc>] (nfs4_remote_mount) from [<c023ef98>] (mount_fs+0x14/0xa4)
[<c023ef98>] (mount_fs) from [<c025cba0>] (vfs_kern_mount+0x54/0x128)
[<c025cba0>] (vfs_kern_mount) from [<c033352c>] (nfs_do_root_mount+0x80/0xa0)
[<c033352c>] (nfs_do_root_mount) from [<c0333818>] (nfs4_try_mount+0x28/0x3c)
[<c0333818>] (nfs4_try_mount) from [<c0313874>] (nfs_fs_mount+0x2cc/0x8c4)
[<c0313874>] (nfs_fs_mount) from [<c023ef98>] (mount_fs+0x14/0xa4)
[<c023ef98>] (mount_fs) from [<c025cba0>] (vfs_kern_mount+0x54/0x128)
[<c025cba0>] (vfs_kern_mount) from [<c02600f0>] (do_mount+0x158/0xc7c)
[<c02600f0>] (do_mount) from [<c0260f98>] (SyS_mount+0x8c/0xb4)
[<c0260f98>] (SyS_mount) from [<c0107840>] (ret_fast_syscall+0x0/0x3c)

Fix the problem by always creating new bdi for a superblock as we used
to do.

Reported-and-tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Fixes: 0d3b12584972ce5781179ad3f15cca3cdb5cae05
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-04 07:57:46 -06:00
..
9p 9p: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
adfs
affs
afs afs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
autofs4
befs
bfs
btrfs Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
cachefiles
ceph Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
cifs Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
coda coda: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
configfs
cramfs
crypto
debugfs
devpts
dlm
ecryptfs ecryptfs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
efivarfs
efs
exofs exofs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
exportfs
ext2
ext4
f2fs
fat
freevxfs
fscache
fuse fuse: Get rid of bdi_initialized 2017-04-20 12:09:55 -06:00
gfs2 fs: Remove SB_I_DYNBDI flag 2017-04-20 12:09:55 -06:00
hfs
hfsplus
hostfs
hpfs
hugetlbfs hugetlbfs: fix offset overflow in hugetlbfs mmap 2017-04-13 18:24:21 -07:00
isofs
jbd2
jffs2
jfs
kernfs
lockd
minix
ncpfs ncpfs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
nfs nfs: Fix bdi handling for cloned superblocks 2017-05-04 07:57:46 -06:00
nfs_common
nfsd Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
nilfs2 fs: Remove SB_I_DYNBDI flag 2017-04-20 12:09:55 -06:00
nls
notify
ntfs
ocfs2
omfs
openpromfs
orangefs orangefs_bufmap_copy_from_iovec(): fix EFAULT handling 2017-04-17 14:23:20 -04:00
overlayfs
proc thp: fix MADV_DONTNEED vs clear soft dirty race 2017-04-13 18:24:21 -07:00
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs sysfs: be careful of error returns from ops->show() 2017-04-08 17:33:32 +02:00
sysv
tracefs
ubifs Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
udf
ufs
xfs Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
Kconfig
Kconfig.binfmt
Makefile
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c block: get rid of blk_integrity_revalidate() 2017-04-21 14:17:27 -06:00
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
coredump.c
dax.c Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block 2017-05-01 10:39:57 -07:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file.c
file_table.c
filesystems.c
fs-writeback.c
fs_pin.c
fs_struct.c
inode.c
internal.h
ioctl.c
iomap.c
libfs.c
locks.c
mbcache.c
mount.h
mpage.c
namei.c vfs: don't do RCU lookup of empty pathnames 2017-04-15 09:34:52 -07:00
namespace.c
no-block.c
nsfs.c nsfs: mark dentry with DCACHE_RCUACCESS 2017-04-19 15:56:24 -07:00
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 statx: correct error handling of NULL pathname 2017-04-27 10:45:09 -07:00
statfs.c
super.c bdi: Drop 'parent' argument from bdi_register[_va]() 2017-04-20 12:09:55 -06:00
sync.c
timerfd.c
userfaultfd.c userfaultfd: report actual registered features in fdinfo 2017-04-08 00:47:48 -07:00
utimes.c
xattr.c