commit 08261673cb upstream.
dq_flags are modified non-atomically in do_set_dqblk via __set_bit calls and
atomically for example in mark_dquot_dirty or clear_dquot_dirty. Hence a
change done by an atomic operation can be overwritten by a change done by a
non-atomic one. Fix the problem by using atomic bitops even in do_set_dqblk.
Signed-off-by: Andrew Perepechko <andrew.perepechko@sun.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 0a5a9c7255 upstream.
If a delayed-allocation write happens before quota is enabled, the
kernel spits out a warning:
WARNING: at fs/quota/dquot.c:988 dquot_claim_space+0x77/0x112()
because the fact that user has some delayed allocation is not recorded
in quota structure.
Make dquot_initialize() update amount of reserved space for user if it sees
inode has some space reserved. Also make sure that reserved quota space does
not go negative and we warn about the filesystem bug just once.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit c469070aea upstream.
Since we implemented generic reserved space management interface,
then it is possible to account reserved space even when quota
is not active (similar to i_blocks/i_bytes).
Without this patch following testcase result in massive comlain from
WARN_ON in dquot_claim_space()
TEST_CASE:
mount /dev/sdb /mnt -oquota
dd if=/dev/zero of=/mnt/test bs=1M count=1
quotaon /mnt
# fs_reserved_spave == 1Mb
# quota_reserved_space == 0, because quota was disabled
dd if=/dev/zero of=/mnt/test seek=1 bs=1M count=1
# fs_reserved_spave == 2Mb
# quota_reserved_space == 1Mb
sync # ->dquot_claim_space() -> WARN_ON
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 05b5d89823 upstream.
Commit fd8fbfc1 modified the way we find amount of reserved space
belonging to an inode. The amount of reserved space is checked
from dquot_transfer and thus inode_reserved_space gets called
even for filesystems that don't provide get_reserved_space callback
which results in a BUG.
Fix the problem by checking get_reserved_space callback and return 0 if
the filesystem does not provide it.
CC: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit fd8fbfc170 upstream.
Currently inode_reservation is managed by fs itself and this
reservation is transfered on dquot_transfer(). This means what
inode_reservation must always be in sync with
dquot->dq_dqb.dqb_rsvspace. Otherwise dquot_transfer() will result
in incorrect quota(WARN_ON in dquot_claim_reserved_space() will be
triggered)
This is not easy because of complex locking order issues
for example http://bugzilla.kernel.org/show_bug.cgi?id=14739
The patch introduce quota reservation field for each fs-inode
(fs specific inode is used in order to prevent bloating generic
vfs inode). This reservation is managed by quota code internally
similar to i_blocks/i_bytes and may not be always in sync with
internal fs reservation.
Also perform some code rearrangement:
- Unify dquot_reserve_space() and dquot_reserve_space()
- Unify dquot_release_reserved_space() and dquot_free_space()
- Also this patch add missing warning update to release_rsv()
dquot_release_reserved_space() must call flush_warnings() as
dquot_free_space() does.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit d01730d74d didn't completely fix
the problem since we still take dqio_mutex and i_mutex in the wrong
order. Move taking of i_mutex further down (luckily it's needed only
for updating inode flags) below where dqio_mutex is taken.
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
The following test script triggers a deadlock on ext2 filesystem:
while true; do quotaon /dev/hda >&/dev/null; usleep $RANDOM; done &
while true; do quotaoff /dev/hda >&/dev/null; usleep $RANDOM; done &
I found there is a potential deadlock between quotaon and quotaoff (or
quotasync). Basically, all of quotactl operations need to be protected by
dqonoff_mutex. vfs_quota_off and vfs_quota_sync also call sb->s_op->quota_write
that needs to grab the i_mutex of the quota file. But in vfs_quota_on_inode
(called from quotaon operation), the current code tries to grab the i_mutex of
the quota file first before getting quonoff_mutex.
Reverse the order in which we take locks in vfs_quota_on_inode().
Jan Kara: Changed changelog to be more readable, made lockdep happy with
I_MUTEX_QUOTA.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Currently the VFS calls vfs_dq_sync to sync out disk quotas for a given
superblock. This is a small wrapper around sync_dquots which for the
case of a non-NULL superblock is a small wrapper around quota_sync_sb.
Just make quota_sync_sb global (rename it to sync_quota_sb) and call it
directly. Also call it directly for those cases in quota.c that have a
superblock and leave sync_dquots purely an iterator over sync_quota_sb and
remove it's superblock argument.
To make this nicer move the check for the lack of a quota_sync method
from the callers into sync_quota_sb.
[folded build fix from Alexander Beregalov <a.beregalov@gmail.com>]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Get rid of useless comments and the equally useless obj-y
initialization.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
clear_inode() will switch inode state from I_FREEING to I_CLEAR, and do so
_outside_ of inode_lock. So any I_FREEING testing is incomplete without a
coupled testing of I_CLEAR.
So add I_CLEAR tests to drop_pagecache_sb(), generic_sync_sb_inodes() and
add_dquot_ref().
Masayoshi MIZUMA discovered the bug in drop_pagecache_sb() and Jan Kara
reminds fixing the other two cases.
Masayoshi MIZUMA has a nice panic flow:
=====================================================================
[process A] | [process B]
| |
| prune_icache() | drop_pagecache()
| spin_lock(&inode_lock) | drop_pagecache_sb()
| inode->i_state |= I_FREEING; | |
| spin_unlock(&inode_lock) | V
| | | spin_lock(&inode_lock)
| V | |
| dispose_list() | |
| list_del() | |
| clear_inode() | |
| inode->i_state = I_CLEAR | |
| | | V
| | | if (inode->i_state & (I_FREEING|I_WILL_FREE))
| | | continue; <==== NOT MATCH
| | |
| | | (DANGER from here on! Accessing disposing inode!)
| | |
| | | __iget()
| | | list_move() <===== PANIC on poisoned list !!
V V |
(time)
=====================================================================
Reported-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6: (27 commits)
ext2: Zero our b_size in ext2_quota_read()
trivial: fix typos/grammar errors in fs/Kconfig
quota: Coding style fixes
quota: Remove superfluous inlines
quota: Remove uppercase aliases for quota functions.
nfsd: Use lowercase names of quota functions
jfs: Use lowercase names of quota functions
udf: Use lowercase names of quota functions
ufs: Use lowercase names of quota functions
reiserfs: Use lowercase names of quota functions
ext4: Use lowercase names of quota functions
ext3: Use lowercase names of quota functions
ext2: Use lowercase names of quota functions
ramfs: Remove quota call
vfs: Use lowercase names of quota functions
quota: Remove dqbuf_t and other cleanups
quota: Remove NODQUOT macro
quota: Make global quota locks cacheline aligned
quota: Move quota files into separate directory
ext4: quota reservation for delayed allocation
...
Remove bogus typedef which is just a definition of char *.
Remove unnecessary type casts.
Substitute freedqbuf() with kfree.
Signed-off-by: Jan Kara <jack@suse.cz>
Andrew Morton has suggested that three global quota locks can end up in the
same cacheline which can result in bad cacheline ping-pong on SMP machines.
Make locks cacheline aligned so that we avoid this problem (thanks goes to
Andrew for the idea).
Signed-off-by: Jan Kara <jack@suse.cz>
CC: Andrew Morton <akpm@linux-foundation.org>
