[Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference
to a workqueue if it happens from the downconvert thread.
Reviewed-by: Mark Fasheh mfas...@suse.de
Reviewed-by: Srinivas Eeda srinivas.e...@oracle.com
Signed-off-by: Jan Kara j...@suse.cz
---
fs/ocfs2/ocfs2.h| 5 +
fs/ocfs2/quota.h| 2 ++
fs/ocfs2/quota_global.c | 35 +++
fs/ocfs2/super.c| 8
4 files changed, 50 insertions(+)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 553f53cc73ae..64c02239ba46 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -30,6 +30,7 @@
#include linux/sched.h
#include linux/wait.h
#include linux/list.h
+#include linux/llist.h
#include linux/rbtree.h
#include linux/workqueue.h
#include linux/kref.h
@@ -419,6 +420,10 @@ struct ocfs2_super
struct ocfs2_dentry_lock *dentry_lock_list;
struct work_struct dentry_lock_work;
+ /* List of dquot structures to drop last reference to */
+ struct llist_head dquot_drop_list;
+ struct work_struct dquot_drop_work;
+
wait_queue_head_t osb_mount_event;
/* Truncate log info */
diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
index d5ab56cbe5c5..f266d67df3c6 100644
--- a/fs/ocfs2/quota.h
+++ b/fs/ocfs2/quota.h
@@ -28,6 +28,7 @@ struct ocfs2_dquot {
unsigned int dq_use_count; /* Number of nodes having reference to
this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
+ struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
@@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64
p_block,
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
+void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index aaa50611ec66..7921e209c64b 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -10,6 +10,7 @@
#include linux/jiffies.h
#include linux/writeback.h
#include linux/workqueue.h
+#include linux/llist.h
#include cluster/masklog.h
@@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block *sb,
int type)
OCFS2_INODE_UPDATE_CREDITS;
}
+void ocfs2_drop_dquot_refs(struct work_struct *work)
+{
+ struct ocfs2_super *osb = container_of(work, struct ocfs2_super,
+ dquot_drop_work);
+ struct llist_node *list;
+ struct ocfs2_dquot *odquot, *next_odquot;
+
+ list = llist_del_all(osb-dquot_drop_list);
+ llist_for_each_entry_safe(odquot, next_odquot, list, list) {
+ /* Drop the reference we acquired in ocfs2_dquot_release() */
+ dqput(odquot-dq_dquot);
+ }
+}
+
+/*
+ * Called when the last reference to dquot is dropped. If we are called from
+ * downconvert thread, we cannot do all the handling here because grabbing
+ * quota lock could deadlock (the node holding the quota lock could need some
+ * other cluster lock to proceed but with blocked downconvert thread we cannot
+ * release any lock).
+ */
static int ocfs2_release_dquot(struct dquot *dquot)
{
handle_t *handle;
@@ -694,6 +716,19 @@ static int ocfs2_release_dquot(struct dquot *dquot)
/* Check
[Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference
to a workqueue if it happens from the downconvert thread.
Reviewed-by: Mark Fasheh mfas...@suse.de
Reviewed-by: Srinivas Eeda srinivas.e...@oracle.com
Signed-off-by: Jan Kara j...@suse.cz
---
fs/ocfs2/ocfs2.h| 5 +
fs/ocfs2/quota.h| 2 ++
fs/ocfs2/quota_global.c | 35 +++
fs/ocfs2/super.c| 8
4 files changed, 50 insertions(+)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 553f53cc73ae..64c02239ba46 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -30,6 +30,7 @@
#include linux/sched.h
#include linux/wait.h
#include linux/list.h
+#include linux/llist.h
#include linux/rbtree.h
#include linux/workqueue.h
#include linux/kref.h
@@ -419,6 +420,10 @@ struct ocfs2_super
struct ocfs2_dentry_lock *dentry_lock_list;
struct work_struct dentry_lock_work;
+ /* List of dquot structures to drop last reference to */
+ struct llist_head dquot_drop_list;
+ struct work_struct dquot_drop_work;
+
wait_queue_head_t osb_mount_event;
/* Truncate log info */
diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
index d5ab56cbe5c5..f266d67df3c6 100644
--- a/fs/ocfs2/quota.h
+++ b/fs/ocfs2/quota.h
@@ -28,6 +28,7 @@ struct ocfs2_dquot {
unsigned int dq_use_count; /* Number of nodes having reference to
this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
+ struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
@@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64
p_block,
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
+void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index aaa50611ec66..7921e209c64b 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -10,6 +10,7 @@
#include linux/jiffies.h
#include linux/writeback.h
#include linux/workqueue.h
+#include linux/llist.h
#include cluster/masklog.h
@@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block *sb,
int type)
OCFS2_INODE_UPDATE_CREDITS;
}
+void ocfs2_drop_dquot_refs(struct work_struct *work)
+{
+ struct ocfs2_super *osb = container_of(work, struct ocfs2_super,
+ dquot_drop_work);
+ struct llist_node *list;
+ struct ocfs2_dquot *odquot, *next_odquot;
+
+ list = llist_del_all(osb-dquot_drop_list);
+ llist_for_each_entry_safe(odquot, next_odquot, list, list) {
+ /* Drop the reference we acquired in ocfs2_dquot_release() */
+ dqput(odquot-dq_dquot);
+ }
+}
+
+/*
+ * Called when the last reference to dquot is dropped. If we are called from
+ * downconvert thread, we cannot do all the handling here because grabbing
+ * quota lock could deadlock (the node holding the quota lock could need some
+ * other cluster lock to proceed but with blocked downconvert thread we cannot
+ * release any lock).
+ */
static int ocfs2_release_dquot(struct dquot *dquot)
{
handle_t *handle;
@@ -694,6 +716,19 @@ static int ocfs2_release_dquot(struct dquot *dquot)
/* Check
Re: [Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
On Fri, Feb 21, 2014 at 10:45:02AM +0100, Jan Kara wrote: We cannot drop last dquot reference from downconvert thread as that creates the following deadlock: NODE 1 NODE2 holds dentry lock for 'foo' holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE dquot_initialize(bar) ocfs2_dquot_acquire() ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE) ... downconvert thread (triggered from another node or a different process from NODE2) ocfs2_dentry_post_unlock() ... iput(foo) ocfs2_evict_inode(foo) ocfs2_clear_inode(foo) dquot_drop(inode) ... ocfs2_dquot_release() ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE) - blocks finds we need more space in quota file ... ocfs2_extend_no_holes() ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE) - deadlocks waiting for downconvert thread We solve the problem by postponing dropping of the last dquot reference to a workqueue if it happens from the downconvert thread. Reviewed-by: Srinivas Eeda srinivas.e...@oracle.com Signed-off-by: Jan Kara j...@suse.cz Looks good, I especially like the usuage of llist. Reviewed-by: Mark Fasheh mfas...@suse.de --Mark -- Mark Fasheh ___ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel
[Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference
to a workqueue if it happens from the downconvert thread.
Reviewed-by: Srinivas Eeda srinivas.e...@oracle.com
Signed-off-by: Jan Kara j...@suse.cz
---
fs/ocfs2/ocfs2.h| 5 +
fs/ocfs2/quota.h| 2 ++
fs/ocfs2/quota_global.c | 35 +++
fs/ocfs2/super.c| 8
4 files changed, 50 insertions(+)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 553f53cc73ae..64c02239ba46 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -30,6 +30,7 @@
#include linux/sched.h
#include linux/wait.h
#include linux/list.h
+#include linux/llist.h
#include linux/rbtree.h
#include linux/workqueue.h
#include linux/kref.h
@@ -419,6 +420,10 @@ struct ocfs2_super
struct ocfs2_dentry_lock *dentry_lock_list;
struct work_struct dentry_lock_work;
+ /* List of dquot structures to drop last reference to */
+ struct llist_head dquot_drop_list;
+ struct work_struct dquot_drop_work;
+
wait_queue_head_t osb_mount_event;
/* Truncate log info */
diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
index d5ab56cbe5c5..f266d67df3c6 100644
--- a/fs/ocfs2/quota.h
+++ b/fs/ocfs2/quota.h
@@ -28,6 +28,7 @@ struct ocfs2_dquot {
unsigned int dq_use_count; /* Number of nodes having reference to
this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
+ struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
@@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64
p_block,
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
+void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index aaa50611ec66..7921e209c64b 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -10,6 +10,7 @@
#include linux/jiffies.h
#include linux/writeback.h
#include linux/workqueue.h
+#include linux/llist.h
#include cluster/masklog.h
@@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block *sb,
int type)
OCFS2_INODE_UPDATE_CREDITS;
}
+void ocfs2_drop_dquot_refs(struct work_struct *work)
+{
+ struct ocfs2_super *osb = container_of(work, struct ocfs2_super,
+ dquot_drop_work);
+ struct llist_node *list;
+ struct ocfs2_dquot *odquot, *next_odquot;
+
+ list = llist_del_all(osb-dquot_drop_list);
+ llist_for_each_entry_safe(odquot, next_odquot, list, list) {
+ /* Drop the reference we acquired in ocfs2_dquot_release() */
+ dqput(odquot-dq_dquot);
+ }
+}
+
+/*
+ * Called when the last reference to dquot is dropped. If we are called from
+ * downconvert thread, we cannot do all the handling here because grabbing
+ * quota lock could deadlock (the node holding the quota lock could need some
+ * other cluster lock to proceed but with blocked downconvert thread we cannot
+ * release any lock).
+ */
static int ocfs2_release_dquot(struct dquot *dquot)
{
handle_t *handle;
@@ -694,6 +716,19 @@ static int ocfs2_release_dquot(struct dquot *dquot)
/* Check whether we are not racing with some other
[Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference
to a workqueue if it happens from the downconvert thread.
Signed-off-by: Jan Kara j...@suse.cz
---
fs/ocfs2/ocfs2.h| 5 +
fs/ocfs2/quota.h| 2 ++
fs/ocfs2/quota_global.c | 35 +++
fs/ocfs2/super.c| 8
4 files changed, 50 insertions(+)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 553f53cc73ae..64c02239ba46 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -30,6 +30,7 @@
#include linux/sched.h
#include linux/wait.h
#include linux/list.h
+#include linux/llist.h
#include linux/rbtree.h
#include linux/workqueue.h
#include linux/kref.h
@@ -419,6 +420,10 @@ struct ocfs2_super
struct ocfs2_dentry_lock *dentry_lock_list;
struct work_struct dentry_lock_work;
+ /* List of dquot structures to drop last reference to */
+ struct llist_head dquot_drop_list;
+ struct work_struct dquot_drop_work;
+
wait_queue_head_t osb_mount_event;
/* Truncate log info */
diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
index d5ab56cbe5c5..f266d67df3c6 100644
--- a/fs/ocfs2/quota.h
+++ b/fs/ocfs2/quota.h
@@ -28,6 +28,7 @@ struct ocfs2_dquot {
unsigned int dq_use_count; /* Number of nodes having reference to
this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
+ struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
@@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64
p_block,
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
+void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index aaa50611ec66..7921e209c64b 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -10,6 +10,7 @@
#include linux/jiffies.h
#include linux/writeback.h
#include linux/workqueue.h
+#include linux/llist.h
#include cluster/masklog.h
@@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block *sb,
int type)
OCFS2_INODE_UPDATE_CREDITS;
}
+void ocfs2_drop_dquot_refs(struct work_struct *work)
+{
+ struct ocfs2_super *osb = container_of(work, struct ocfs2_super,
+ dquot_drop_work);
+ struct llist_node *list;
+ struct ocfs2_dquot *odquot, *next_odquot;
+
+ list = llist_del_all(osb-dquot_drop_list);
+ llist_for_each_entry_safe(odquot, next_odquot, list, list) {
+ /* Drop the reference we acquired in ocfs2_dquot_release() */
+ dqput(odquot-dq_dquot);
+ }
+}
+
+/*
+ * Called when the last reference to dquot is dropped. If we are called from
+ * downconvert thread, we cannot do all the handling here because grabbing
+ * quota lock could deadlock (the node holding the quota lock could need some
+ * other cluster lock to proceed but with blocked downconvert thread we cannot
+ * release any lock).
+ */
static int ocfs2_release_dquot(struct dquot *dquot)
{
handle_t *handle;
@@ -694,6 +716,19 @@ static int ocfs2_release_dquot(struct dquot *dquot)
/* Check whether we are not racing with some other dqget() */
if (atomic_read(dquot-dq_count)
Re: [Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference
looks good to me
Reviewed-by: Srinivas Eeda srinivas.e...@oracle.com
On 02/20/2014 07:18 AM, Jan Kara wrote:
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:
NODE 1 NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
dquot_initialize(bar)
ocfs2_dquot_acquire()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
...
downconvert thread (triggered from another
node or a different process from NODE2)
ocfs2_dentry_post_unlock()
...
iput(foo)
ocfs2_evict_inode(foo)
ocfs2_clear_inode(foo)
dquot_drop(inode)
...
ocfs2_dquot_release()
ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
- blocks
finds we need more space in
quota file
...
ocfs2_extend_no_holes()
ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
- deadlocks waiting for
downconvert thread
We solve the problem by postponing dropping of the last dquot reference
to a workqueue if it happens from the downconvert thread.
Signed-off-by: Jan Kara j...@suse.cz
---
fs/ocfs2/ocfs2.h| 5 +
fs/ocfs2/quota.h| 2 ++
fs/ocfs2/quota_global.c | 35 +++
fs/ocfs2/super.c| 8
4 files changed, 50 insertions(+)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 553f53cc73ae..64c02239ba46 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -30,6 +30,7 @@
#include linux/sched.h
#include linux/wait.h
#include linux/list.h
+#include linux/llist.h
#include linux/rbtree.h
#include linux/workqueue.h
#include linux/kref.h
@@ -419,6 +420,10 @@ struct ocfs2_super
struct ocfs2_dentry_lock *dentry_lock_list;
struct work_struct dentry_lock_work;
+ /* List of dquot structures to drop last reference to */
+ struct llist_head dquot_drop_list;
+ struct work_struct dquot_drop_work;
+
wait_queue_head_t osb_mount_event;
/* Truncate log info */
diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h
index d5ab56cbe5c5..f266d67df3c6 100644
--- a/fs/ocfs2/quota.h
+++ b/fs/ocfs2/quota.h
@@ -28,6 +28,7 @@ struct ocfs2_dquot {
unsigned int dq_use_count; /* Number of nodes having reference to
this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
+ struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
@@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64
p_block,
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
+void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index aaa50611ec66..7921e209c64b 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -10,6 +10,7 @@
#include linux/jiffies.h
#include linux/writeback.h
#include linux/workqueue.h
+#include linux/llist.h
#include cluster/masklog.h
@@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block
*sb, int type)
OCFS2_INODE_UPDATE_CREDITS;
}
+void ocfs2_drop_dquot_refs(struct work_struct *work)
+{
+ struct ocfs2_super *osb = container_of(work, struct ocfs2_super,
+dquot_drop_work);
+ struct llist_node *list;
+ struct ocfs2_dquot *odquot, *next_odquot;
+
+ list = llist_del_all(osb-dquot_drop_list);
+ llist_for_each_entry_safe(odquot, next_odquot, list, list) {
+ /* Drop the reference we acquired in ocfs2_dquot_release() */
+ dqput(odquot-dq_dquot);
+ }
+}
+
+/*
+ * Called when the last reference to dquot is dropped. If we are called from
+ * downconvert thread, we cannot do all the handling here because grabbing
+ * quota lock could deadlock (the node holding the quota lock could need some
+ * other cluster lock to proceed but with blocked downconvert thread we
cannot
+ * release any lock).
+ */
static int
