linux/fs
Carsten Otte 0e4a9b5928 ext2/xip: refuse to change xip flag during remount with busy inodes
For a reason that I was unable to understand in three months of debugging,
mount ext2 -o remount stopped working properly when remounting from
regular operation to xip, or the other way around.  According to a git
bisect search, the problem was introduced with the VM_MIXEDMAP/PTE_SPECIAL
rework in the vm:

commit 70688e4dd1
Author: Nick Piggin <npiggin@suse.de>
Date:   Mon Apr 28 02:13:02 2008 -0700

    xip: support non-struct page backed memory

In the failing scenario, the filesystem is mounted read only via root=
kernel parameter on s390x.  During remount (in rc.sysinit), the inodes of
the bash binary and its libraries are busy and cannot be invalidated (the
bash which is running rc.sysinit resides on subject filesystem).
Afterwards, another bash process (running ifup-eth) recurses into a
subshell, runs dup_mm (via fork).  Some of the mappings in this bash
process were created from inodes that could not be invalidated during
remount.

Both parent and child process crash some time later due to inconsistencies
in their address spaces.  The issue seems to be timing sensitive, various
attempts to recreate it have failed.

This patch refuses to change the xip flag during remount in case some
inodes cannot be invalidated.  This patch keeps users from running into
that issue.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Jared Hulbert <jaredeh@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-11 14:25:36 -08:00
..
9p fs/Kconfig: move 9p out 2009-01-22 13:16:01 +03:00
adfs fs/Kconfig: move adfs out 2009-01-22 13:15:56 +03:00
affs fs/Kconfig: move affs out 2009-01-22 13:15:56 +03:00
afs fs/Kconfig: move afs out 2009-01-22 13:16:01 +03:00
autofs fs/Kconfig: move autofs, autofs4 out 2009-01-22 13:15:54 +03:00
autofs4 fs/Kconfig: move autofs, autofs4 out 2009-01-22 13:15:54 +03:00
befs fs/Kconfig: move befs out 2009-01-22 13:15:57 +03:00
bfs fs/Kconfig: move bfs out 2009-01-22 13:15:57 +03:00
btrfs Btrfs: don't use spin_is_contended 2009-02-09 16:22:03 -05:00
cifs cifs: make sure we allocate enough storage for socket address 2009-01-29 03:32:13 +00:00
coda fs/Kconfig: move coda out 2009-01-22 13:16:01 +03:00
configfs Revert "configfs: Silence lockdep on mkdir(), rmdir() and configfs_depend_item()" 2009-02-04 09:46:25 -08:00
cramfs fs/Kconfig: move cramfs out 2009-01-22 13:15:58 +03:00
debugfs debugfs: add helpers for exporting a size_t simple value 2009-01-07 10:00:16 -08:00
devpts zero i_uid/i_gid on inode allocation 2009-01-05 11:54:28 -05:00
dlm dlm: initialize file_lock struct in GETLK before copying conflicting lock 2009-01-21 15:28:45 -06:00
ecryptfs eCryptfs: Regression in unencrypted filename symlinks 2009-02-06 18:36:40 -08:00
efs fs/Kconfig: move efs out 2009-01-22 13:15:57 +03:00
exportfs Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
ext2 ext2/xip: refuse to change xip flag during remount with busy inodes 2009-02-11 14:25:36 -08:00
ext3 ext3: revert "ext3: wait on all pending commits in ext3_sync_fs" 2009-02-11 14:25:35 -08:00
ext4 ext4: Remove bogus BUG() check in ext4_bmap() 2009-01-30 00:00:24 -05:00
fat fs/Kconfig: move fat out 2009-01-22 13:15:55 +03:00
freevxfs fs/Kconfig: move vxfs out 2009-01-22 13:15:58 +03:00
fuse Merge branch 'Kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/misc 2009-01-26 10:08:50 -08:00
gfs2 filesystem freeze: add error handling of write_super_lockfs/unlockfs 2009-01-09 16:54:42 -08:00
hfs fs/Kconfig: move hfs, hfsplus out 2009-01-22 13:15:57 +03:00
hfsplus fs/Kconfig: move hfs, hfsplus out 2009-01-22 13:15:57 +03:00
hostfs fs: symlink write_begin allocation context fix 2009-01-04 13:33:20 -08:00
hpfs fs/Kconfig: move hpfs out 2009-01-22 13:15:59 +03:00
hppfs CRED: Use creds in file structs 2008-11-14 10:39:25 +11:00
hugetlbfs Do not account for the address space used by hugetlbfs using VM_ACCOUNT 2009-02-10 10:48:42 -08:00
isofs fs/Kconfig: move iso9660, udf out 2009-01-22 13:15:55 +03:00
jbd jbd: fix return value of journal_start_commit() 2009-02-11 14:25:35 -08:00
jbd2 ext4: fix wrong use of do_div 2009-01-11 22:34:01 -05:00
jffs2 [JFFS2] remove junk prototypes 2009-01-09 21:05:21 +00:00
jfs fs/Kconfig: move jfs out 2009-01-22 13:15:54 +03:00
lockd lockd: fix regression in lockd's handling of blocked locks 2009-02-09 13:19:46 -05:00
minix fs/Kconfig: move minix out 2009-01-22 13:15:58 +03:00
ncpfs fs/Kconfig: move the rest of ncpfs out 2009-01-22 13:16:01 +03:00
nfs fs/Kconfig: move nfs out 2009-01-22 13:16:00 +03:00
nfs_common SUNRPC: nfsacl_encode/nfsacl_decode should be exported as GPL-only 2008-12-23 15:21:32 -05:00
nfsd nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found 2009-01-27 17:26:59 -05:00
nls remove CONFIG_KMOD from fs 2008-10-17 02:38:36 +11:00
notify inotify: clean up inotify_read and fix locking problems 2009-01-26 10:08:05 -08:00
ntfs fs/Kconfig: move ntfs out 2009-01-22 13:15:55 +03:00
ocfs2 ocfs2: add quota call to ocfs2_remove_btree_range() 2009-02-02 14:20:20 -08:00
omfs fs/Kconfig: move omfs out 2009-01-22 13:15:58 +03:00
openpromfs zero i_uid/i_gid on inode allocation 2009-01-05 11:54:28 -05:00
partitions block: fix bug in ptbl lookup cache 2009-01-09 21:46:13 +01:00
proc Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu 2009-01-09 14:00:58 -08:00
qnx4 fs/Kconfig: move qnx4 out 2009-01-22 13:15:59 +03:00
ramfs NOMMU: Fix cleanup handling in ramfs_nommu_get_umapped_area() 2009-01-08 12:04:46 +00:00
reiserfs fs/Kconfig: move reiserfs out 2009-01-22 13:15:53 +03:00
romfs fs/Kconfig: move romfs out 2009-01-22 13:15:59 +03:00
smbfs fs/Kconfig: move smbfs out 2009-01-22 13:16:01 +03:00
squashfs fs/Kconfig: move squashfs out 2009-01-22 13:15:58 +03:00
sysfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 2009-01-26 10:40:28 -08:00
sysv fs/Kconfig: move sysv out 2009-01-22 13:15:59 +03:00
ubifs UBIFS: remove fast unmounting 2009-01-29 16:34:30 +02:00
udf fs/Kconfig: move iso9660, udf out 2009-01-22 13:15:55 +03:00
ufs fs/Kconfig: move ufs out 2009-01-22 13:16:00 +03:00
xfs [XFS] Warn on transaction in flight on read-only remount 2009-02-03 11:04:54 -06:00
aio.c [CVE-2009-0029] System call wrappers part 16 2009-01-14 14:15:25 +01:00
anon_inodes.c anon_inodes: use fops->owner for module refcount 2008-12-31 16:55:44 +02:00
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 sanitize ifdefs in binfmt_aout 2009-01-03 11:45:54 -08:00
binfmt_elf_fdpic.c FDPIC: Don't attempt to expand the userspace stack to fill the space allocated 2009-01-08 12:04:47 +00:00
binfmt_elf.c elf core dump: fix get_user use 2009-02-06 17:34:07 -08:00
binfmt_em86.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_flat.c FLAT: Don't attempt to expand the userspace stack to fill the space allocated 2009-01-08 12:04:47 +00:00
binfmt_misc.c fs/binfmt_misc.c: add terminating newline to /proc/sys/fs/binfmt_misc/status 2009-01-06 15:59:19 -08:00
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 block: Remove obsolete BUG_ON 2009-01-30 12:34:36 +01:00
bio.c [SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITE 2009-01-02 11:10:35 -06:00
block_dev.c filesystem freeze: implement generic freeze feature 2009-01-09 16:54:42 -08:00
buffer.c vfs: Don't call attach_nobh_buffers() with an empty list 2009-02-06 13:34:22 -08:00
char_dev.c fs: fix name overwrite in __register_chrdev_region() 2009-01-06 15:59:13 -08:00
compat_binfmt_elf.c
compat_ioctl.c braino in sg_ioctl_trans() 2009-02-05 16:35:52 -08:00
compat.c CRED: Fix SUID exec regression 2009-02-07 08:46:18 +11:00
dcache.c [CVE-2009-0029] System call wrappers part 20 2009-01-14 14:15:26 +01:00
dcookies.c [CVE-2009-0029] System call wrapper special cases 2009-01-14 14:15:18 +01:00
direct-io.c fs: truncate blocks outside i_size after O_DIRECT write error 2009-01-06 15:59:06 -08:00
dquot.c quota: Improve locking 2009-01-16 18:02:10 +01:00
drop_caches.c
eventfd.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
eventpoll.c epoll: drop max_user_instances and rely only on max_user_watches 2009-01-29 18:04:45 -08:00
exec.c CRED: Fix SUID exec regression 2009-02-07 08:46:18 +11:00
fcntl.c [CVE-2009-0029] System call wrappers part 15 2009-01-14 14:15:24 +01:00
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 [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
fs-writeback.c fs: sys_sync fix 2009-01-06 15:59:09 -08:00
generic_acl.c
inode.c partial revert of asynchronous inode delete 2009-01-09 13:15:49 -08:00
internal.h CRED: Fix SUID exec regression 2009-02-07 08:46:18 +11:00
ioctl.c [CVE-2009-0029] System call wrappers part 15 2009-01-14 14:15:24 +01:00
ioprio.c [CVE-2009-0029] System call wrappers part 28 2009-01-14 14:15:30 +01:00
Kconfig fs/Kconfig: move 9p out 2009-01-22 13:16:01 +03:00
Kconfig.binfmt CORE_DUMP_DEFAULT_ELF_HEADERS depends on ELF_CORE 2009-01-09 16:54:41 -08:00
libfs.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-01-05 18:32:06 -08:00
locks.c [CVE-2009-0029] System call wrappers part 16 2009-01-14 14:15:25 +01:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus 2009-01-09 15:18:49 -08:00
mbcache.c
mpage.c do_mpage_readpage(): remove useless clear_buffer_mapped() call 2009-01-06 15:59:01 -08:00
namei.c [CVE-2009-0029] System call wrappers part 29 2009-01-14 14:15:30 +01:00
namespace.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
nfsctl.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
no-block.c
open.c [CVE-2009-0029] System call wrappers part 30 2009-01-14 14:15:30 +01:00
pipe.c [CVE-2009-0029] System call wrappers part 33 2009-01-14 14:15:32 +01:00
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_tree.c quota: Split off quota tree handling into a separate file 2009-01-05 08:40:21 -08:00
quota_tree.h quota: Split off quota tree handling into a separate file 2009-01-05 08:40:21 -08:00
quota_v1.c quota: Move quotaio_v[12].h from include/linux/ to fs/ 2009-01-05 08:36:58 -08:00
quota_v2.c quota: Convert union in mem_dqinfo to a pointer 2009-01-05 08:40:21 -08:00
quota.c [CVE-2009-0029] System call wrappers part 20 2009-01-14 14:15:26 +01:00
quotaio_v1.h quota: Move quotaio_v[12].h from include/linux/ to fs/ 2009-01-05 08:36:58 -08:00
quotaio_v2.h quota: Split off quota tree handling into a separate file 2009-01-05 08:40:21 -08:00
read_write.c [CVE-2009-0029] System call wrappers part 20 2009-01-14 14:15:26 +01:00
read_write.h
readdir.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
select.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
seq_file.c seq_file: fix big-enough lseek() + read() 2009-02-05 14:18:14 -08:00
signalfd.c [CVE-2009-0029] System call wrappers part 31 2009-01-14 14:15:31 +01:00
splice.c [CVE-2009-0029] System call wrappers part 31 2009-01-14 14:15:31 +01:00
stack.c
stat.c [CVE-2009-0029] System call wrappers part 30 2009-01-14 14:15:30 +01:00
super.c async: Rename _special -> _domain for clarity. 2009-02-08 09:56:11 -08:00
sync.c [CVE-2009-0029] System call wrappers part 09 2009-01-14 14:15:21 +01:00
timerfd.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
utimes.c [CVE-2009-0029] System call wrappers part 30 2009-01-14 14:15:30 +01:00
xattr_acl.c
xattr.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00