Hi Andrew,
here's patch which should fix deadlock with quotas+ext3 reported in
2.4 (the same problem existed in 2.6 but nobody found it). Please apply.
The patch is against 2.6.0-test9 but should apply to -test10 too.
Honza
-----------------------<cut>---------------------------------------
diff -ruX ../kerndiffexclude linux-2.6.0-test9-syncfix/fs/dquot.c linux-2.6.0-test9-ext3deadlock/fs/dquot.c
--- linux-2.6.0-test9-syncfix/fs/dquot.c Mon Nov 24 10:31:41 2003
+++ linux-2.6.0-test9-ext3deadlock/fs/dquot.c Mon Nov 24 10:08:11 2003
@@ -344,7 +344,7 @@
atomic_inc(&dquot->dq_count);
dqstats.lookups++;
spin_unlock(&dq_list_lock);
- sb->dq_op->sync_dquot(dquot);
+ sb->dq_op->write_dquot(dquot);
dqput(dquot);
goto restart;
}
@@ -432,7 +432,7 @@
}
if (dquot_dirty(dquot)) {
spin_unlock(&dq_list_lock);
- commit_dqblk(dquot);
+ dquot->dq_sb->dq_op->write_dquot(dquot);
goto we_slept;
}
atomic_dec(&dquot->dq_count);
@@ -1088,7 +1088,7 @@
.free_space = dquot_free_space,
.free_inode = dquot_free_inode,
.transfer = dquot_transfer,
- .sync_dquot = commit_dqblk
+ .write_dquot = commit_dqblk
};
/* Function used by filesystems for initializing the dquot_operations structure */
@@ -1212,9 +1212,9 @@
error = -EINVAL;
if (!fmt->qf_ops->check_quota_file(sb, type))
goto out_file_init;
- /* We don't want quota on quota files */
+ /* We don't want quota and atime on quota files (deadlocks possible) */
dquot_drop_nolock(inode);
- inode->i_flags |= S_NOQUOTA;
+ inode->i_flags |= S_NOQUOTA | S_NOATIME;
dqopt->ops[type] = fmt->qf_ops;
dqopt->info[type].dqi_format = fmt;
diff -ruX ../kerndiffexclude linux-2.6.0-test9-syncfix/fs/ext3/super.c linux-2.6.0-test9-ext3deadlock/fs/ext3/super.c
--- linux-2.6.0-test9-syncfix/fs/ext3/super.c Sat Oct 25 20:44:40 2003
+++ linux-2.6.0-test9-ext3deadlock/fs/ext3/super.c Mon Nov 24 09:59:27 2003
@@ -1944,9 +1944,9 @@
/* Blocks: quota info + (4 pointer blocks + 1 entry block) * (3 indirect + 1 descriptor + 1 bitmap) + superblock */
#define EXT3_V0_QFMT_BLOCKS 27
-static int (*old_sync_dquot)(struct dquot *dquot);
+static int (*old_write_dquot)(struct dquot *dquot);
-static int ext3_sync_dquot(struct dquot *dquot)
+static int ext3_write_dquot(struct dquot *dquot)
{
int nblocks;
int ret;
@@ -1971,7 +1971,7 @@
ret = PTR_ERR(handle);
goto out;
}
- ret = old_sync_dquot(dquot);
+ ret = old_write_dquot(dquot);
err = ext3_journal_stop(handle);
if (ret == 0)
ret = err;
@@ -2004,8 +2004,8 @@
goto out1;
#ifdef CONFIG_QUOTA
init_dquot_operations(&ext3_qops);
- old_sync_dquot = ext3_qops.sync_dquot;
- ext3_qops.sync_dquot = ext3_sync_dquot;
+ old_write_dquot = ext3_qops.write_dquot;
+ ext3_qops.write_dquot = ext3_write_dquot;
#endif
err = register_filesystem(&ext3_fs_type);
if (err)
diff -ruX ../kerndiffexclude linux-2.6.0-test9-syncfix/include/linux/quota.h linux-2.6.0-test9-ext3deadlock/include/linux/quota.h
--- linux-2.6.0-test9-syncfix/include/linux/quota.h Sat Oct 25 20:44:10 2003
+++ linux-2.6.0-test9-ext3deadlock/include/linux/quota.h Mon Nov 24 10:00:19 2003
@@ -250,7 +250,7 @@
void (*free_space) (struct inode *, qsize_t);
void (*free_inode) (const struct inode *, unsigned long);
int (*transfer) (struct inode *, struct iattr *);
- int (*sync_dquot) (struct dquot *);
+ int (*write_dquot) (struct dquot *);
};
/* Operations handling requests from userspace */