The patch titled
lockdep: annotate the quota code
has been added to the -mm tree. Its filename is
lockdep-annotate-the-quota-code.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep: annotate the quota code
From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
The quota code plays interesting games with the lock ordering; to quote Jan:
| i_mutex of inode containing quota file is acquired after all other
| quota locks. i_mutex of all other inodes is acquired before quota
| locks. Quota code makes sure (by resetting inode operations and
| setting special flag on inode) that noone tries to enter quota code
| while holding i_mutex on a quota file...
The good news is that all of this special case i_mutex grabbing happens in the
(per filesystem) low level quota write function. For this special case we
need a new I_MUTEX_* nesting level, since this just entirely outside any of
the regular VFS locking rules for i_mutex. I trust Jan on his blue eyes that
this is not ever going to deadlock; and based on that the patch below is what
it takes to inform lockdep of these very interesting new locking rules.
The new locking rule for the I_MUTEX_QUOTA nesting level is that this is the
deepest possible level of nesting for i_mutex, and that this only should be
used in quota write (and possibly read) function of filesystems. This makes
the lock ordering of the I_MUTEX_* levels:
I_MUTEX_PARENT -> I_MUTEX_CHILD -> I_MUTEX_NORMAL -> I_MUTEX_QUOTA
Has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Jan Kara <jack@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/ext2/super.c | 2 +-
fs/ext3/super.c | 2 +-
fs/reiserfs/super.c | 2 +-
fs/ufs/super.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff -puN fs/ext2/super.c~lockdep-annotate-the-quota-code fs/ext2/super.c
--- a/fs/ext2/super.c~lockdep-annotate-the-quota-code
+++ a/fs/ext2/super.c
@@ -1158,7 +1158,7 @@ static ssize_t ext2_quota_write(struct s
struct buffer_head tmp_bh;
struct buffer_head *bh;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
diff -puN fs/ext3/super.c~lockdep-annotate-the-quota-code fs/ext3/super.c
--- a/fs/ext3/super.c~lockdep-annotate-the-quota-code
+++ a/fs/ext3/super.c
@@ -2615,7 +2615,7 @@ static ssize_t ext3_quota_write(struct s
struct buffer_head *bh;
handle_t *handle = journal_current_handle();
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
diff -puN fs/reiserfs/super.c~lockdep-annotate-the-quota-code fs/reiserfs/super.c
--- a/fs/reiserfs/super.c~lockdep-annotate-the-quota-code
+++ a/fs/reiserfs/super.c
@@ -2073,7 +2073,7 @@ static ssize_t reiserfs_quota_write(stru
size_t towrite = len;
struct buffer_head tmp_bh, *bh;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
diff -puN fs/ufs/super.c~lockdep-annotate-the-quota-code fs/ufs/super.c
--- a/fs/ufs/super.c~lockdep-annotate-the-quota-code
+++ a/fs/ufs/super.c
@@ -1327,7 +1327,7 @@ static ssize_t ufs_quota_write(struct su
size_t towrite = len;
struct buffer_head *bh;
- mutex_lock(&inode->i_mutex);
+ mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
_
Patches currently in -mm which might be from arjan@xxxxxxxxxxxxxxx are
origin.patch
cpu_relax-smpbootc.patch
lock-validator-introduce-warn_on_oncecond.patch
emu10k1-mark-midi_spinlock-as-used.patch
epoll-use-unlocked-wqueue-operations.patch
lock-validator-fix-ns83820c-irq-flags-bug.patch
i386-fix-softirq-accounting-with-4k-stacks.patch
add-export_unused_symbol-and-export_unused_symbol_gpl.patch
add-export_unused_symbol-and-export_unused_symbol_gpl-default.patch
spin-rwlock-init-cleanups.patch
pi-futex-futex-code-cleanups.patch
pi-futex-introduce-debug_check_no_locks_freed.patch
pi-futex-add-plist-implementation.patch
pi-futex-scheduler-support-for-pi.patch
pi-futex-rt-mutex-core.patch
pi-futex-rt-mutex-docs.patch
pi-futex-rt-mutex-debug.patch
pi-futex-rt-mutex-tester.patch
pi-futex-rt-mutex-tester-fix.patch
pi-futex-rt-mutex-futex-api.patch
pi-futex-futex_lock_pi-futex_unlock_pi-support.patch
lockdep-floppyc-irq-release-fix.patch
lockdep-add-is_module_address.patch
lockdep-add-per_cpu_offset.patch
lockdep-better-lock-debugging.patch
lockdep-mutex-section-binutils-workaround.patch
lockdep-locking-init-debugging-improvement.patch
lockdep-beautify-x86_64-stacktraces.patch
lockdep-x86_64-document-stack-frame-internals.patch
lockdep-stacktrace-subsystem-core.patch
lockdep-stacktrace-subsystem-i386-support.patch
lockdep-stacktrace-subsystem-x86_64-support.patch
lockdep-irqtrace-subsystem-core.patch
lockdep-locking-api-self-tests.patch
lockdep-irqtrace-cleanup-of-include-asm-i386-irqflagsh.patch
lockdep-irqtrace-cleanup-of-include-asm-x86_64-irqflagsh.patch
lockdep-core.patch
lockdep-design-docs.patch
lockdep-procfs.patch
lockdep-prove-rwsem-locking-correctness.patch
lockdep-prove-spinlock-rwlock-locking-correctness.patch
lockdep-prove-mutex-locking-correctness.patch
lockdep-kconfig.patch
lockdep-print-all-lock-classes-on-sysrq-d.patch
lockdep-x86_64-early-init.patch
lockdep-x86-smp-alternatives-workaround.patch
lockdep-do-not-recurse-in-printk.patch
lockdep-fix-rt_hash_lock_sz.patch
lockdep-annotate-direct-io.patch
lockdep-annotate-serial.patch
lockdep-annotate-dcache.patch
lockdep-annotate-i_mutex.patch
lockdep-annotate-futex.patch
lockdep-annotate-genirq.patch
lockdep-annotate-waitqueues.patch
lockdep-annotate-mm.patch
lockdep-annotate-serio.patch
lockdep-annotate-skb_queue_head_init.patch
lockdep-annotate-timer-base-locks.patch
lockdep-annotate-scheduler-runqueue-locks.patch
lockdep-annotate-hrtimer-base-locks.patch
lockdep-annotate-sock_lock_init.patch
lockdep-annotate-af_unix-locking.patch
lockdep-annotate-bh_lock_sock.patch
lockdep-annotate-mmap_sem.patch
lockdep-annotate-sunrpc-code.patch
lockdep-annotate-the-quota-code.patch
lockdep-annotate-usbfs.patch
lockdep-annotate-sound-core-seq-seq_portsc.patch
lockdep-annotate-sound-core-seq-seq_devicec.patch
lockdep-annotate-8390c-disable_irq.patch
lockdep-annotate-3c59xc-disable_irq.patch
lockdep-annotate-forcedethc-disable_irq.patch
lockdep-annotate-enable_in_hardirq.patch
lockdep-annotate-s_lock.patch
lockdep-annotate-sb-s_umount.patch
lockdep-annotate-slab-code.patch
lockdep-annotate-blkdev-nesting.patch
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