From: Jan Kara <jack@ucw.cz>
Attached patch should fix reported deadlock in journalled quota code.
quotactl() call was violating the locking rules and didn't start transaction
when it should.
---
25-akpm/fs/dquot.c | 6 ++++--
25-akpm/fs/ext3/super.c | 36 ++++++++++++++++++++++++++++++++++++
25-akpm/include/linux/quota.h | 2 ++
3 files changed, 42 insertions(+), 2 deletions(-)
diff -puN fs/dquot.c~fix-deadlock-in-journalled-quota fs/dquot.c
--- 25/fs/dquot.c~fix-deadlock-in-journalled-quota Wed Apr 28 15:09:05 2004
+++ 25-akpm/fs/dquot.c Wed Apr 28 15:09:05 2004
@@ -529,7 +529,7 @@ we_slept:
clear_dquot_dirty(dquot);
if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
spin_unlock(&dq_list_lock);
- dquot_release(dquot);
+ dquot->dq_sb->dq_op->release_dquot(dquot);
goto we_slept;
}
atomic_dec(&dquot->dq_count);
@@ -605,7 +605,7 @@ we_slept:
* finished or it will be canceled due to dq_count > 1 test */
wait_on_dquot(dquot);
/* Read the dquot and instantiate it (everything done only if needed) */
- if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_acquire(dquot) < 0) {
+ if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) {
dqput(dquot);
return NODQUOT;
}
@@ -1259,6 +1259,8 @@ struct dquot_operations dquot_operations
.free_inode = dquot_free_inode,
.transfer = dquot_transfer,
.write_dquot = dquot_commit,
+ .acquire_dquot = dquot_acquire,
+ .release_dquot = dquot_release,
.mark_dirty = dquot_mark_dquot_dirty,
.write_info = dquot_commit_info
};
diff -puN fs/ext3/super.c~fix-deadlock-in-journalled-quota fs/ext3/super.c
--- 25/fs/ext3/super.c~fix-deadlock-in-journalled-quota Wed Apr 28 15:09:05 2004
+++ 25-akpm/fs/ext3/super.c Wed Apr 28 15:09:55 2004
@@ -521,6 +521,8 @@ static void ext3_clear_inode(struct inod
static int ext3_dquot_initialize(struct inode *inode, int type);
static int ext3_dquot_drop(struct inode *inode);
static int ext3_write_dquot(struct dquot *dquot);
+static int ext3_acquire_dquot(struct dquot *dquot);
+static int ext3_release_dquot(struct dquot *dquot);
static int ext3_mark_dquot_dirty(struct dquot *dquot);
static int ext3_write_info(struct super_block *sb, int type);
static int ext3_quota_on(struct super_block *sb, int type, int format_id, char *path);
@@ -536,6 +538,8 @@ static struct dquot_operations ext3_quot
.free_inode = dquot_free_inode,
.transfer = dquot_transfer,
.write_dquot = ext3_write_dquot,
+ .acquire_dquot = ext3_acquire_dquot,
+ .release_dquot = ext3_release_dquot,
.mark_dirty = ext3_mark_dquot_dirty,
.write_info = ext3_write_info
};
@@ -2178,6 +2182,38 @@ static int ext3_write_dquot(struct dquot
err = ext3_journal_stop(handle);
if (!ret)
ret = err;
+ return ret;
+}
+
+static int ext3_acquire_dquot(struct dquot *dquot)
+{
+ int ret, err;
+ handle_t *handle;
+
+ handle = ext3_journal_start(dquot_to_inode(dquot),
+ EXT3_QUOTA_INIT_BLOCKS);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ ret = dquot_acquire(dquot);
+ err = ext3_journal_stop(handle);
+ if (!ret)
+ ret = err;
+ return ret;
+}
+
+static int ext3_release_dquot(struct dquot *dquot)
+{
+ int ret, err;
+ handle_t *handle;
+
+ handle = ext3_journal_start(dquot_to_inode(dquot),
+ EXT3_QUOTA_INIT_BLOCKS);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ ret = dquot_release(dquot);
+ err = ext3_journal_stop(handle);
+ if (!ret)
+ ret = err;
return ret;
}
diff -puN include/linux/quota.h~fix-deadlock-in-journalled-quota include/linux/quota.h
--- 25/include/linux/quota.h~fix-deadlock-in-journalled-quota Wed Apr 28 15:09:05 2004
+++ 25-akpm/include/linux/quota.h Wed Apr 28 15:09:05 2004
@@ -250,6 +250,8 @@ struct dquot_operations {
int (*free_inode) (const struct inode *, unsigned long);
int (*transfer) (struct inode *, struct iattr *);
int (*write_dquot) (struct dquot *); /* Ordinary dquot write */
+ int (*acquire_dquot) (struct dquot *); /* Quota is going to be created on disk */
+ int (*release_dquot) (struct dquot *); /* Quota is going to be deleted from disk */
int (*mark_dirty) (struct dquot *); /* Dquot is marked dirty */
int (*write_info) (struct super_block *, int); /* Write of quota "superblock" */
};
_