Testing with the fscache overhaul has triggered some lockdep warnings
about circular lock dependencies involving page_mkwrite and the
mmap_lock. It'd be better to do the "real work" without the mmap lock
being held.
Change the skip_checking_caps parameter in __ceph_put_cap_refs to an
enum, and use that to determine whether to queue check_caps, do it
synchronously or not at all. Change ceph_page_mkwrite to do a
ceph_put_cap_refs_async().
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/addr.c | 2 +-
fs/ceph/caps.c | 28 ++++++++++++++++++++++++----
fs/ceph/inode.c | 6 ++++++
fs/ceph/super.h | 19 ++++++++++++++++---
4 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 950552944436..26e66436f005 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1662,7 +1662,7 @@ static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %x\n",
inode, off, len, ceph_cap_string(got), ret);
- ceph_put_cap_refs(ci, got);
+ ceph_put_cap_refs_async(ci, got);
out_free:
ceph_restore_sigs(&oldset);
sb_end_pagefault(inode->i_sb);
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 336348e733b9..a95ab4c02056 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3026,6 +3026,12 @@ static int ceph_try_drop_cap_snap(struct ceph_inode_info *ci,
return 0;
}
+enum PutCapRefsMode {
+ PutCapRefsModeSync = 0,
+ PutCapRefsModeSkip,
+ PutCapRefsModeAsync,
+};
+
/*
* Release cap refs.
*
@@ -3036,7 +3042,7 @@ static int ceph_try_drop_cap_snap(struct ceph_inode_info *ci,
* cap_snap, and wake up any waiters.
*/
static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
- bool skip_checking_caps)
+ enum PutCapRefsMode mode)
{
struct inode *inode = &ci->vfs_inode;
int last = 0, put = 0, flushsnaps = 0, wake = 0;
@@ -3092,11 +3098,20 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
last ? " last" : "", put ? " put" : "");
- if (!skip_checking_caps) {
+ switch(mode) {
+ default:
+ break;
+ case PutCapRefsModeSync:
if (last)
ceph_check_caps(ci, 0, NULL);
else if (flushsnaps)
ceph_flush_snaps(ci, NULL);
+ break;
+ case PutCapRefsModeAsync:
+ if (last)
+ ceph_queue_check_caps(inode);
+ else if (flushsnaps)
+ ceph_queue_flush_snaps(inode);
}
if (wake)
wake_up_all(&ci->i_cap_wq);
@@ -3106,12 +3121,17 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
{
- __ceph_put_cap_refs(ci, had, false);
+ __ceph_put_cap_refs(ci, had, PutCapRefsModeSync);
+}
+
+void ceph_put_cap_refs_async(struct ceph_inode_info *ci, int had)
+{
+ __ceph_put_cap_refs(ci, had, PutCapRefsModeAsync);
}
void ceph_put_cap_refs_no_check_caps(struct ceph_inode_info *ci, int had)
{
- __ceph_put_cap_refs(ci, had, true);
+ __ceph_put_cap_refs(ci, had, PutCapRefsModeSkip);
}
/*
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 9cd8b37e586a..a7ee19e27e26 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1965,6 +1965,12 @@ static void ceph_inode_work(struct work_struct *work)
if (test_and_clear_bit(CEPH_I_WORK_VMTRUNCATE, &ci->i_work_mask))
__ceph_do_pending_vmtruncate(inode);
+ if (test_and_clear_bit(CEPH_I_WORK_CHECK_CAPS, &ci->i_work_mask))
+ ceph_check_caps(ci, 0, NULL);
+
+ if (test_and_clear_bit(CEPH_I_WORK_FLUSH_SNAPS, &ci->i_work_mask))
+ ceph_flush_snaps(ci, NULL);
+
iput(inode);
}
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 59153ee201c0..13b02887b085 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -562,9 +562,11 @@ static inline struct inode *ceph_find_inode(struct super_block *sb,
/*
* Masks of ceph inode work.
*/
-#define CEPH_I_WORK_WRITEBACK 0 /* writeback */
-#define CEPH_I_WORK_INVALIDATE_PAGES 1 /* invalidate pages */
-#define CEPH_I_WORK_VMTRUNCATE 2 /* vmtruncate */
+#define CEPH_I_WORK_WRITEBACK 0
+#define CEPH_I_WORK_INVALIDATE_PAGES 1
+#define CEPH_I_WORK_VMTRUNCATE 2
+#define CEPH_I_WORK_CHECK_CAPS 3
+#define CEPH_I_WORK_FLUSH_SNAPS 4
/*
* We set the ERROR_WRITE bit when we start seeing write errors on an inode
@@ -982,6 +984,16 @@ static inline void ceph_queue_writeback(struct inode *inode)
ceph_queue_inode_work(inode, CEPH_I_WORK_WRITEBACK);
}
+static inline void ceph_queue_check_caps(struct inode *inode)
+{
+ ceph_queue_inode_work(inode, CEPH_I_WORK_CHECK_CAPS);
+}
+
+static inline void ceph_queue_flush_snaps(struct inode *inode)
+{
+ ceph_queue_inode_work(inode, CEPH_I_WORK_FLUSH_SNAPS);
+}
+
extern int __ceph_do_getattr(struct inode *inode, struct page *locked_page,
int mask, bool force);
static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
@@ -1120,6 +1132,7 @@ extern void ceph_take_cap_refs(struct ceph_inode_info *ci, int caps,
bool snap_rwsem_locked);
extern void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps);
extern void ceph_put_cap_refs(struct ceph_inode_info *ci, int had);
+extern void ceph_put_cap_refs_async(struct ceph_inode_info *ci, int had);
extern void ceph_put_cap_refs_no_check_caps(struct ceph_inode_info *ci,
int had);
extern void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
--
2.29.2
