NFSv4.1/pnfs: replace broken pnfs_put_lseg_async

commit 6543f803670530f6aa93790d9fa116d8395a537d upstream.

You cannot call pnfs_put_lseg_async() more than once per lseg, so it
is really an inappropriate way to deal with a refcount issue.

Instead, replace it with a function that decrements the refcount, and
puts the final 'free' operation (which is incompatible with locks) on
the workqueue.

Cc: Weston Andros Adamson <dros@primarydata.com>
Fixes: e6cf82d1830f: pnfs: add pnfs_put_lseg_async
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 90978075f7302a791813b6dd29c0ec9f9e5850eb..f59713e091a822f9776c818cbc04a116d0d2254d 100644 (file)
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1031,7 +1031,7 @@ filelayout_clear_request_commit(struct nfs_page *req,
        }
 out:
        nfs_request_remove_commit_list(req, cinfo);
-       pnfs_put_lseg_async(freeme);
+       pnfs_put_lseg_locked(freeme);
 }
 
 static void

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index a3851debf8a2f481435b3750f5cb1bec678ab4fe..5480720bdc0facb1533b51f2854de65fae7a7832 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -361,22 +361,43 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 }
 EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 
-static void pnfs_put_lseg_async_work(struct work_struct *work)
+static void pnfs_free_lseg_async_work(struct work_struct *work)
 {
        struct pnfs_layout_segment *lseg;
+       struct pnfs_layout_hdr *lo;
 
        lseg = container_of(work, struct pnfs_layout_segment, pls_work);
+       lo = lseg->pls_layout;
 
-       pnfs_put_lseg(lseg);
+       pnfs_free_lseg(lseg);
+       pnfs_put_layout_hdr(lo);
 }
 
-void
-pnfs_put_lseg_async(struct pnfs_layout_segment *lseg)
+static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
 {
-       INIT_WORK(&lseg->pls_work, pnfs_put_lseg_async_work);
+       INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
        schedule_work(&lseg->pls_work);
 }
-EXPORT_SYMBOL_GPL(pnfs_put_lseg_async);
+
+void
+pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
+{
+       if (!lseg)
+               return;
+
+       assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
+
+       dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
+               atomic_read(&lseg->pls_refcount),
+               test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
+       if (atomic_dec_and_test(&lseg->pls_refcount)) {
+               struct pnfs_layout_hdr *lo = lseg->pls_layout;
+               pnfs_get_layout_hdr(lo);
+               pnfs_layout_remove_lseg(lo, lseg);
+               pnfs_free_lseg_async(lseg);
+       }
+}
+EXPORT_SYMBOL_GPL(pnfs_put_lseg_locked);
 
 static u64
 end_offset(u64 start, u64 len)

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index aca3dff5dae63e3a5d41f3e43b7055e77372b841..bc2db1c2a5eed80064e2fc138502fcbefe038f92 100644 (file)
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -183,7 +183,7 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
 /* pnfs.c */
 void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
-void pnfs_put_lseg_async(struct pnfs_layout_segment *lseg);
+void pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg);
 
 void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
 void unset_pnfs_layoutdriver(struct nfs_server *);
@@ -422,10 +422,6 @@ static inline void pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 {
 }
 
-static inline void pnfs_put_lseg_async(struct pnfs_layout_segment *lseg)
-{
-}
-
 static inline int pnfs_return_layout(struct inode *ino)
 {
        return 0;