The patch titled
lockdep: annotate the quota code
has been removed from the -mm tree. Its filename is
lockdep-annotate-the-quota-code.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
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
@@ -1157,7 +1157,7 @@ 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
@@ -2614,7 +2614,7 @@ 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
@@ -2203,7 +2203,7 @@ 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
@@ -1326,7 +1326,7 @@ 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
lock-validator-fix-ns83820c-irq-flags-bug.patch
sleazy-fpu-feature-x86_64-support.patch
sleazy-fpu-feature-x86_64-support-fix.patch
sleazy-fpu-feature-i386-support.patch
delay-accounting-taskstats-interface-send-tgid-once.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
