linux/fs
Brian Foster a27ba2607e xfs: detect agfl count corruption and reset agfl
The struct xfs_agfl v5 header was originally introduced with
unexpected padding that caused the AGFL to operate with one less
slot than intended. The header has since been packed, but the fix
left an incompatibility for users who upgrade from an old kernel
with the unpacked header to a newer kernel with the packed header
while the AGFL happens to wrap around the end. The newer kernel
recognizes one extra slot at the physical end of the AGFL that the
previous kernel did not. The new kernel will eventually attempt to
allocate a block from that slot, which contains invalid data, and
cause a crash.

This condition can be detected by comparing the active range of the
AGFL to the count. While this detects a padding mismatch, it can
also trigger false positives for unrelated flcount corruption. Since
we cannot distinguish a size mismatch due to padding from unrelated
corruption, we can't trust the AGFL enough to simply repopulate the
empty slot.

Instead, avoid unnecessarily complex detection logic and and use a
solution that can handle any form of flcount corruption that slips
through read verifiers: distrust the entire AGFL and reset it to an
empty state. Any valid blocks within the AGFL are intentionally
leaked. This requires xfs_repair to rectify (which was already
necessary based on the state the AGFL was found in). The reset
mitigates the side effect of the padding mismatch problem from a
filesystem crash to a free space accounting inconsistency. The
generic approach also means that this patch can be safely backported
to kernels with or without a packed struct xfs_agfl.

Check the AGF for an invalid freelist count on initial read from
disk. If detected, set a flag on the xfs_perag to indicate that a
reset is required before the AGFL can be used. In the first
transaction that attempts to use a flagged AGFL, reset it to empty,
warn the user about the inconsistency and allow the freelist fixup
code to repopulate the AGFL with new blocks. The xfs_perag flag is
cleared to eliminate the need for repeated checks on each block
allocation operation.

This allows kernels that include the packing fix commit 96f859d52b
("libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct")
to handle older unpacked AGFL formats without a filesystem crash.

Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by Dave Chiluk <chiluk+linuxxfs@indeed.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-23 18:05:06 -07:00
..
9p fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
adfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
affs iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw} 2018-02-01 08:15:25 -05:00
afs afs: Support the AFS dynamic root 2018-02-06 14:43:37 +00:00
autofs4 Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-01-30 14:43:12 -08:00
befs befs: Define usercopy region in befs_inode_cache slab cache 2018-01-15 12:07:54 -08:00
bfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btrfs for-4.16-rc3-tag 2018-03-04 11:04:27 -08:00
cachefiles vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ceph ceph: fix potential memory leak in init_caches() 2018-03-01 16:39:47 +01:00
cifs Add missing structs and defines from recent SMB3.1.1 documentation 2018-02-07 09:36:46 -06:00
coda vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
configfs configfs: make ci_type field, some pointers and function arguments const 2017-10-19 16:15:16 +02:00
cramfs cramfs: better MTD dependency expression 2018-02-08 11:37:31 -08:00
crypto fscrypt: fix build with pre-4.6 gcc versions 2018-02-01 10:51:18 -05:00
debugfs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
devpts devpts: fix error handling in devpts_mntget() 2018-01-31 08:48:37 -08:00
dlm vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ecryptfs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
efivarfs efivarfs: Limit the rate for non-root to read files 2018-02-22 10:21:02 -08:00
efs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
exofs iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
exportfs
ext2 iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
ext4 iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
f2fs Refactor support for encrypted symlinks to move common code to fscrypt. 2018-02-04 10:43:12 -08:00
fat iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw} 2018-02-01 08:15:25 -05:00
freevxfs vxfs: Define usercopy region in vxfs_inode slab cache 2018-01-15 12:07:57 -08:00
fscache AFS development 2017-11-16 11:41:22 -08:00
fuse vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
gfs2 gfs2: Fixes to "Implement iomap for block_map" (2) 2018-03-07 11:40:38 -07:00
hfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
hfsplus hfsplus: honor setgid flag on directories 2018-02-06 18:32:45 -08:00
hostfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hpfs hpfs: don't bother with the i_version counter or f_version 2017-12-10 12:58:18 -08:00
hugetlbfs hugetlb: implement memfd sealing 2018-01-31 17:18:39 -08:00
isofs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
jbd2 jbd2: fix sphinx kernel-doc build warnings 2018-01-10 00:27:29 -05:00
jffs2 Documentation updates for 4.16. New stuff includes refcount_t 2018-01-31 19:25:25 -08:00
jfs Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
kernfs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
lockd lockd: Fix server refcounting 2018-01-24 17:33:57 -05:00
minix Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
nfs NFS: make struct nlmclnt_fl_close_lock_ops static 2018-02-22 12:23:01 -05:00
nfs_common lockd: fix "list_add double add" caused by legacy signal interface 2017-11-27 16:45:11 -05:00
nfsd This request is late, apologies. 2018-02-08 15:18:32 -08:00
nilfs2 nilfs2: use time64_t internally 2018-02-06 18:32:45 -08:00
nls License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
notify vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ntfs ntfs: remove i_version handling 2018-01-01 10:09:33 -05:00
ocfs2 vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
omfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
openpromfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
orangefs vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
overlayfs ovl: update Kconfig texts 2018-03-07 11:47:15 +01:00
proc Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:31:51 -08:00
pstore fs: pstore: remove unused hardirq.h 2017-11-28 16:39:09 -08:00
qnx4 Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
qnx6 Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
quota quota: Check for register_shrinker() failure. 2017-11-29 16:46:48 +01:00
ramfs mm: make pagevec_lookup() update index 2017-09-06 17:27:26 -07:00
reiserfs fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
romfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
squashfs Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
sysv Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
tracefs VFS: Don't use save/replace_mount_options if not using generic_show_options 2017-07-06 03:31:46 -04:00
ubifs Refactor support for encrypted symlinks to move common code to fscrypt. 2018-02-04 10:43:12 -08:00
udf udf: Sanitize nanoseconds for time stamps 2017-12-19 08:11:01 +01:00
ufs iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
xfs xfs: detect agfl count corruption and reset agfl 2018-03-23 18:05:06 -07:00
aio.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 11:54:55 -08:00
anon_inodes.c
attr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bad_inode.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_aout.c fs: fix kernel_read prototype 2017-09-04 19:05:15 -04:00
binfmt_elf_fdpic.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:54:01 -08:00
binfmt_elf.c elf: fix NT_FILE integer overflow 2018-02-06 18:32:45 -08:00
binfmt_em86.c
binfmt_flat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_misc.c fs/binfmt_misc.c: node could be NULL when evicting inode 2017-10-13 16:18:33 -07:00
binfmt_script.c exec: load_script: kill the onstack interp[BINPRM_BUF_SIZE] array 2017-10-03 17:54:25 -07:00
block_dev.c blockdev: Avoid two active bdev inodes for one device 2018-02-26 09:48:42 -07:00
buffer.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
char_dev.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_binfmt_elf.c
compat_ioctl.c fs: compat_ioctl: add new DVB demux ioctls 2017-12-28 11:17:29 -05:00
compat.c
coredump.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 11:54:55 -08:00
dax.c Only miscellaneous cleanups and bug fixes for ext4 this cycle. 2018-02-03 13:49:22 -08:00
dcache.c Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2018-02-05 13:05:20 -08:00
dcookies.c
direct-io.c direct-io: Fix sleep in atomic due to sync AIO 2018-02-26 09:05:35 -07:00
drop_caches.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eventfd.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
eventpoll.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
exec.c exec: Weaken dumpability for secureexec 2018-01-03 10:13:36 -08:00
fcntl.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
fhandle.c vfs: Copy struct mount.mnt_id to userspace using put_user() 2018-01-15 12:07:51 -08:00
file_table.c vfs: remove unused hardirq.h 2017-12-07 14:23:30 -05:00
file.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
filesystems.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs_pin.c Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
fs_struct.c
fs-writeback.c writeback: update comment in inode_io_list_move_locked 2018-01-06 09:18:00 -07:00
inode.c inode: don't memset the inode address space twice 2018-03-11 20:27:56 -07:00
internal.h fs: expose do_unlinkat for built-in callers 2017-11-10 08:48:46 -05:00
ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap.c iomap: warn on zero-length mappings 2018-01-29 07:27:24 -08:00
Kconfig libnvdimm for 4.16 2018-02-06 10:41:33 -08:00
Kconfig.binfmt ARM: enable elf_fdpic on systems with an MMU 2017-09-10 19:31:46 -04:00
libfs.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
locks.c This request is late, apologies. 2018-02-08 15:18:32 -08:00
Makefile ncpfs: move net/ncpfs to drivers/staging/ncpfs 2017-11-28 13:55:01 +01:00
mbcache.c mbcache: make sure c_entry_count is not decremented past zero 2018-01-09 23:57:52 -05:00
mount.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpage.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
namespace.c VFS: Handle lazytime in do_mount() 2017-12-09 20:16:33 -05:00
no-block.c
nsfs.c nsfs: generalize ns_get_path() for path resolution with a task 2017-12-31 16:12:23 +01:00
open.c ovl: don't allow writing ioctl on lower layer 2017-09-05 12:53:12 +02:00
pipe.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
pnode.c
pnode.h
posix_acl.c posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t 2018-01-02 19:27:28 -08:00
proc_namespace.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
read_write.c Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:08:18 -08:00
readdir.c Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
select.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
seq_file.c seq_file: fix incomplete reset on read from zero offset 2018-01-20 02:31:15 -05:00
signalfd.c fs/signalfd: fix build error for BUS_MCEERR_AR 2018-02-22 15:00:07 -06:00
splice.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
stack.c
stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
statfs.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
super.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
sync.c fs: don't clear I_DIRTY_TIME before calling mark_inode_dirty_sync 2018-03-11 20:27:55 -07:00
timerfd.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
userfaultfd.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
utimes.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr.c lsm: fix smack_inode_removexattr and xattr_getsecurity memleak 2017-10-04 18:03:15 +11:00