linux-toradex.git/fs/ext4/xattr.c, branch v4.9.85

ext4: lock the xattr block before checksuming it

2017-03-30T07:41:25+00:00

commit dac7a4b4b1f664934e8b713f529b629f67db313c upstream.

We must lock the xattr block before calculating or verifying the
checksum in order to avoid spurious checksum failures.

https://bugzilla.kernel.org/show_bug.cgi?id=193661

Reported-by: Colin Ian King 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix deadlock between inline_data and ext4_expand_extra_isize_ea()

2017-03-12T05:41:41+00:00

commit c755e251357a0cee0679081f08c3f4ba797a8009 upstream.

The xattr_sem deadlock problems fixed in commit 2e81a4eeedca: "ext4:
avoid deadlock when expanding inode size" didn't include the use of
xattr_sem in fs/ext4/inline.c.  With the addition of project quota
which added a new extra inode field, this exposed deadlocks in the
inline_data code similar to the ones fixed by 2e81a4eeedca.

The deadlock can be reproduced via:

   dmesg -n 7
   mke2fs -t ext4 -O inline_data -Fq -I 256 /dev/vdc 32768
   mount -t ext4 -o debug_want_extra_isize=24 /dev/vdc /vdc
   mkdir /vdc/a
   umount /vdc
   mount -t ext4 /dev/vdc /vdc
   echo foo > /vdc/a/foo

and looks like this:

[   11.158815]
[   11.160276] =============================================
[   11.161960] [ INFO: possible recursive locking detected ]
[   11.161960] 4.10.0-rc3-00015-g011b30a8a3cf #160 Tainted: G        W
[   11.161960] ---------------------------------------------
[   11.161960] bash/2519 is trying to acquire lock:
[   11.161960]  (&ei->xattr_sem){++++..}, at: [] ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]
[   11.161960] but task is already holding lock:
[   11.161960]  (&ei->xattr_sem){++++..}, at: [] ext4_try_add_inline_entry+0x3a/0x152
[   11.161960]
[   11.161960] other info that might help us debug this:
[   11.161960]  Possible unsafe locking scenario:
[   11.161960]
[   11.161960]        CPU0
[   11.161960]        ----
[   11.161960]   lock(&ei->xattr_sem);
[   11.161960]   lock(&ei->xattr_sem);
[   11.161960]
[   11.161960]  *** DEADLOCK ***
[   11.161960]
[   11.161960]  May be due to missing lock nesting notation
[   11.161960]
[   11.161960] 4 locks held by bash/2519:
[   11.161960]  #0:  (sb_writers#3){.+.+.+}, at: [] mnt_want_write+0x1e/0x3e
[   11.161960]  #1:  (&type->i_mutex_dir_key){++++++}, at: [] path_openat+0x338/0x67a
[   11.161960]  #2:  (jbd2_handle){++++..}, at: [] start_this_handle+0x582/0x622
[   11.161960]  #3:  (&ei->xattr_sem){++++..}, at: [] ext4_try_add_inline_entry+0x3a/0x152
[   11.161960]
[   11.161960] stack backtrace:
[   11.161960] CPU: 0 PID: 2519 Comm: bash Tainted: G        W       4.10.0-rc3-00015-g011b30a8a3cf #160
[   11.161960] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1 04/01/2014
[   11.161960] Call Trace:
[   11.161960]  dump_stack+0x72/0xa3
[   11.161960]  __lock_acquire+0xb7c/0xcb9
[   11.161960]  ? kvm_clock_read+0x1f/0x29
[   11.161960]  ? __lock_is_held+0x36/0x66
[   11.161960]  ? __lock_is_held+0x36/0x66
[   11.161960]  lock_acquire+0x106/0x18a
[   11.161960]  ? ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  down_write+0x39/0x72
[   11.161960]  ? ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  ? _raw_read_unlock+0x22/0x2c
[   11.161960]  ? jbd2_journal_extend+0x1e2/0x262
[   11.161960]  ? __ext4_journal_get_write_access+0x3d/0x60
[   11.161960]  ext4_mark_inode_dirty+0x17d/0x26d
[   11.161960]  ? ext4_add_dirent_to_inline.isra.12+0xa5/0xb2
[   11.161960]  ext4_add_dirent_to_inline.isra.12+0xa5/0xb2
[   11.161960]  ext4_try_add_inline_entry+0x69/0x152
[   11.161960]  ext4_add_entry+0xa3/0x848
[   11.161960]  ? __brelse+0x14/0x2f
[   11.161960]  ? _raw_spin_unlock_irqrestore+0x44/0x4f
[   11.161960]  ext4_add_nondir+0x17/0x5b
[   11.161960]  ext4_create+0xcf/0x133
[   11.161960]  ? ext4_mknod+0x12f/0x12f
[   11.161960]  lookup_open+0x39e/0x3fb
[   11.161960]  ? __wake_up+0x1a/0x40
[   11.161960]  ? lock_acquire+0x11e/0x18a
[   11.161960]  path_openat+0x35c/0x67a
[   11.161960]  ? sched_clock_cpu+0xd7/0xf2
[   11.161960]  do_filp_open+0x36/0x7c
[   11.161960]  ? _raw_spin_unlock+0x22/0x2c
[   11.161960]  ? __alloc_fd+0x169/0x173
[   11.161960]  do_sys_open+0x59/0xcc
[   11.161960]  SyS_open+0x1d/0x1f
[   11.161960]  do_int80_syscall_32+0x4f/0x61
[   11.161960]  entry_INT80_32+0x2f/0x2f
[   11.161960] EIP: 0xb76ad469
[   11.161960] EFLAGS: 00000286 CPU: 0
[   11.161960] EAX: ffffffda EBX: 08168ac8 ECX: 00008241 EDX: 000001b6
[   11.161960] ESI: b75e46bc EDI: b7755000 EBP: bfbdb108 ESP: bfbdafc0
[   11.161960]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b

Reported-by: George Spelvin 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: add missing KERN_CONT to a few more debugging uses

2016-10-15T13:57:31+00:00

Recent commits require line continuing printks to always use
pr_cont or KERN_CONT.  Add these markings to a few more printks.

Miscellaneaous:

o Integrate the ea_idebug and ea_bdebug macros to use a single
  call to printk(KERN_DEBUG instead of 3 separate printks
o Use the more common varargs macro style

Signed-off-by: Joe Perches 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger

ext4: correct endianness conversion in __xattr_check_inode()

2016-10-15T13:39:31+00:00

It should be cpu_to_le32(), not le32_to_cpu().  No change in behavior.

Found with sparse, and this was the only endianness warning in fs/ext4/.

Signed-off-by: Eric Biggers 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara

ext4: factor out loop for freeing inode xattr space

2016-08-29T19:44:11+00:00

Move loop to make enough space in the inode from
ext4_expand_extra_isize_ea() into a separate function to make that
function smaller and better readable and also to avoid delaration of
variables inside a loop block.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: remove (almost) unused variables from ext4_expand_extra_isize_ea()

2016-08-29T19:43:11+00:00

'start' variable is completely unused in ext4_expand_extra_isize_ea().
Variable 'first' is used only once in one place. So just remove them.
Variables 'entry' and 'last' are only really used later in the function
inside a loop. Move their declarations there.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: factor out xattr moving

2016-08-29T19:42:11+00:00

Factor out function for moving xattrs from inode into external xattr
block from ext4_expand_extra_isize_ea(). That function is already quite
long and factoring out this rather standalone functionality helps
readability.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: replace bogus assertion in ext4_xattr_shift_entries()

2016-08-29T19:41:11+00:00

We were checking whether computed offsets do not exceed end of block in
ext4_xattr_shift_entries(). However this does not make sense since we
always only decrease offsets. So replace that assertion with a check
whether we really decrease xattrs value offsets.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: remove checks for e_value_block

2016-08-29T19:40:11+00:00

Currently we don't support xattrs with e_value_block set. We don't allow
them to pass initial xattr check so there's no point for checking for
this later. Since these tests were untested, bugs were creeping in and
not all places which should have checked were checking e_value_block
anyway.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: Check that external xattr value block is zero

2016-08-29T19:39:11+00:00

Currently we don't support xattrs with values stored out of line. Check
for that in ext4_xattr_check_names() to make sure we never work with
such xattrs since not all the code counts with that resulting is possible
weird corruption issues.

Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o