linux-stable.git/fs/ext4, branch v3.12.41

ext4: prevent bugon on race between write/fcntl

2015-02-09T09:19:55+00:00

commit a41537e69b4aa43f0fea02498c2595a81267383b upstream.

O_DIRECT flags can be toggeled via fcntl(F_SETFL). But this value checked
twice inside ext4_file_write_iter() and __generic_file_write() which
result in BUG_ON inside ext4_direct_IO.

Let's initialize iocb->private unconditionally.

TESTCASE: xfstest:generic/036  https://patchwork.ozlabs.org/patch/402445/

#TYPICAL STACK TRACE:
kernel BUG at fs/ext4/inode.c:2960!
invalid opcode: 0000 [#1] SMP
Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
CPU: 6 PID: 5505 Comm: aio-dio-fcntl-r Not tainted 3.17.0-rc2-00176-gff5c017 #161
Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
task: ffff88080e95a7c0 ti: ffff88080f908000 task.ti: ffff88080f908000
RIP: 0010:[]  [] ext4_direct_IO+0x162/0x3d0
RSP: 0018:ffff88080f90bb58  EFLAGS: 00010246
RAX: 0000000000000400 RBX: ffff88080fdb2a28 RCX: 00000000a802c818
RDX: 0000040000080000 RSI: ffff88080d8aeb80 RDI: 0000000000000001
RBP: ffff88080f90bbc8 R08: 0000000000000000 R09: 0000000000001581
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88080d8aeb80
R13: ffff88080f90bbf8 R14: ffff88080fdb28c8 R15: ffff88080fdb2a28
FS:  00007f23b2055700(0000) GS:ffff880818400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23b2045000 CR3: 000000080cedf000 CR4: 00000000000407e0
Stack:
 ffff88080f90bb98 0000000000000000 7ffffffffffffffe ffff88080fdb2c30
 0000000000000200 0000000000000200 0000000000000001 0000000000000200
 ffff88080f90bbc8 ffff88080fdb2c30 ffff88080f90be08 0000000000000200
Call Trace:
 [] generic_file_direct_write+0xed/0x180
 [] __generic_file_write_iter+0x222/0x370
 [] ext4_file_write_iter+0x34b/0x400
 [] ? aio_run_iocb+0x239/0x410
 [] ? aio_run_iocb+0x239/0x410
 [] ? local_clock+0x25/0x30
 [] ? __lock_acquire+0x274/0x700
 [] ? ext4_unwritten_wait+0xb0/0xb0
 [] aio_run_iocb+0x286/0x410
 [] ? local_clock+0x25/0x30
 [] ? lock_release_holdtime+0x29/0x190
 [] ? lookup_ioctx+0x4b/0xf0
 [] do_io_submit+0x55b/0x740
 [] ? do_io_submit+0x3ca/0x740
 [] SyS_io_submit+0x10/0x20
 [] system_call_fastpath+0x16/0x1b
Code: 01 48 8b 80 f0 01 00 00 48 8b 18 49 8b 45 10 0f 85 f1 01 00 00 48 03 45 c8 48 3b 43 48 0f 8f e3 01 00 00 49 83 7c
24 18 00 75 04 <0f> 0b eb fe f0 ff 83 ec 01 00 00 49 8b 44 24 18 8b 00 85 c0 89
RIP  [] ext4_direct_IO+0x162/0x3d0
 RSP 

Reported-by: Sasha Levin 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Dmitry Monakhov 
[hujianyang: Backported to 3.10
 - Move initialization of iocb->private to ext4_file_write() as we don't
   have ext4_file_write_iter(), which is introduced by commit 9b884164.
 - Adjust context to make 'overwrite' changes apply to ext4_file_dio_write()
   as ext4_file_dio_write() is not move into ext4_file_write()]
Signed-off-by: hujianyang 
Signed-off-by: Jiri Slaby

ext4: atomically set inode->i_flags in ext4_set_inode_flags()

2014-12-03T10:58:43+00:00

commit 5f16f3225b06242a9ee876f07c1c9b6ed36a22b6 upstream.

Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

js: there is no change for ext4. This patch defines merely
    inode_set_flags for jffs in the next patch. I wonder why do we
    have both inode_set_flags and set_mask_bits? Looks like an
    improperly resolved merge conflict.

Reported-by: John Sullivan 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@kernel.org
Signed-off-by: Jiri Slaby

fix O_SYNC|O_APPEND syncing the wrong range on write()

2014-12-03T10:58:41+00:00

commit d311d79de305f1ada47cadd672e6ed1b28a949eb upstream.

It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
	pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
	pos_before_write .. pos_before_write + written - 1
instead.  Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().

All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().

The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.

Signed-off-by: Al Viro 
Signed-off-by: Jiri Slaby

ext4: fix oops when loading block bitmap failed

2014-11-13T18:02:37+00:00

commit 599a9b77ab289d85c2d5c8607624efbe1f552b0f upstream.

When we fail to load block bitmap in __ext4_new_inode() we will
dereference NULL pointer in ext4_journal_get_write_access(). So check
for error from ext4_read_block_bitmap().

Coverity-id: 989065
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: enable journal checksum when metadata checksum feature enabled

2014-11-13T18:02:37+00:00

commit 98c1a7593fa355fda7f5a5940c8bf5326ca964ba upstream.

If metadata checksumming is turned on for the FS, we need to tell the
journal to use checksumming too.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix overflow when updating superblock backups after resize

2014-11-13T18:02:36+00:00

commit 9378c6768e4fca48971e7b6a9075bc006eda981d upstream.

When there are no meta block groups update_backups() will compute the
backup block in 32-bit arithmetics thus possibly overflowing the block
number and corrupting the filesystem. OTOH filesystems without meta
block groups larger than 16 TB should be rare. Fix the problem by doing
the counting in 64-bit arithmetics.

Coverity-id: 741252
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Lukas Czerner 
Signed-off-by: Jiri Slaby

ext4: check s_chksum_driver when looking for bg csum presence

2014-11-13T18:02:36+00:00

commit 813d32f91333e4c33d5a19b67167c4bae42dae75 upstream.

Convert the ext4_has_group_desc_csum predicate to look for a checksum
driver instead of the metadata_csum flag and change the bg checksum
calculation function to look for GDT_CSUM before taking the crc16
path.

Without this patch, if we mount with ^uninit_bg,^metadata_csum and
later metadata_csum gets turned on by accident, the block group
checksum functions will incorrectly assume that checksumming is
enabled (metadata_csum) but that crc16 should be used
(!s_chksum_driver).  This is totally wrong, so fix the predicate
and the checksum formula selection.

(Granted, if the metadata_csum feature bit gets enabled on a live FS
then something underhanded is going on, but we could at least avoid
writing garbage into the on-disk fields.)

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Dmitry Monakhov 
Signed-off-by: Jiri Slaby

ext4: Replace open coded mdata csum feature to helper function

2014-11-13T18:02:35+00:00

commit 9aa5d32ba269bec0e7eaba2697a986a7b0bc8528 upstream.

Besides the fact that this replacement improves code readability
it also protects from errors caused direct EXT4_S(sb)->s_es manipulation
which may result attempt to use uninitialized  csum machinery.

#Testcase_BEGIN
IMG=/dev/ram0
MNT=/mnt
mkfs.ext4 $IMG
mount $IMG $MNT
#Enable feature directly on disk, on mounted fs
tune2fs -O metadata_csum  $IMG
# Provoke metadata update, likey result in OOPS
touch $MNT/test
umount $MNT
#Testcase_END

# Replacement script
@@
expression E;
@@
- EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
+ ext4_has_metadata_csum(E)

https://bugzilla.kernel.org/show_bug.cgi?id=82201

Signed-off-by: Dmitry Monakhov 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix reservation overflow in ext4_da_write_begin

2014-11-13T18:02:35+00:00

commit 0ff8947fc5f700172b37cbca811a38eb9cb81e08 upstream.

Delalloc write journal reservations only reserve 1 credit,
to update the inode if necessary.  However, it may happen
once in a filesystem's lifetime that a file will cross
the 2G threshold, and require the LARGE_FILE feature to
be set in the superblock as well, if it was not set already.

This overruns the transaction reservation, and can be
demonstrated simply on any ext4 filesystem without the LARGE_FILE
feature already set:

dd if=/dev/zero of=testfile bs=1 seek=2147483646 count=1 \
	conv=notrunc of=testfile
sync
dd if=/dev/zero of=testfile bs=1 seek=2147483647 count=1 \
	conv=notrunc of=testfile

leads to:

EXT4-fs: ext4_do_update_inode:4296: aborting transaction: error 28 in __ext4_handle_dirty_super
EXT4-fs error (device loop0) in ext4_do_update_inode:4301: error 28
EXT4-fs error (device loop0) in ext4_reserve_inode_write:4757: Readonly filesystem
EXT4-fs error (device loop0) in ext4_dirty_inode:4876: error 28
EXT4-fs error (device loop0) in ext4_da_write_end:2685: error 28

Adjust the number of credits based on whether the flag is
already set, and whether the current write may extend past the
LARGE_FILE limit.

Signed-off-by: Eric Sandeen 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Signed-off-by: Jiri Slaby

ext4: add ext4_iget_normal() which is to be used for dir tree lookups

2014-11-13T18:02:34+00:00

commit f4bb2981024fc91b23b4d09a8817c415396dbabb upstream.

If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes.  This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.

In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.

Reported-by: Sami Liedes 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby