From: Fred Isaman <iisaman@netapp.com>
To: linux-nfs@vger.kernel.org
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Subject: [PATCH 11/15] pnfs: change lo refcounting to atomic_t
Date: Thu, 23 Dec 2010 18:54:37 -0500 [thread overview]
Message-ID: <1293148481-28420-12-git-send-email-iisaman@netapp.com> (raw)
In-Reply-To: <1293148481-28420-1-git-send-email-iisaman@netapp.com>
This will be required to allow us to grab reference outside of i_lock.
While we are at it, make put_layout_hdr take the same argument as all the
related functions.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
fs/nfs/pnfs.c | 48 ++++++++++++++++++++++++++----------------------
fs/nfs/pnfs.h | 4 ++--
2 files changed, 28 insertions(+), 24 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index cd99064..32b6646 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -177,34 +177,38 @@ EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
* pNFS client layout cache
*/
+/* Need to hold i_lock if caller does not already hold reference */
static void
-get_layout_hdr_locked(struct pnfs_layout_hdr *lo)
+get_layout_hdr(struct pnfs_layout_hdr *lo)
{
- assert_spin_locked(&lo->plh_inode->i_lock);
- lo->plh_refcount++;
+ atomic_inc(&lo->plh_refcount);
}
static void
-put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
+destroy_layout_hdr(struct pnfs_layout_hdr *lo)
{
- assert_spin_locked(&lo->plh_inode->i_lock);
- BUG_ON(lo->plh_refcount == 0);
+ dprintk("%s: freeing layout cache %p\n", __func__, lo);
+ BUG_ON(!list_empty(&lo->plh_layouts));
+ NFS_I(lo->plh_inode)->layout = NULL;
+ kfree(lo);
+}
- lo->plh_refcount--;
- if (!lo->plh_refcount) {
- dprintk("%s: freeing layout cache %p\n", __func__, lo);
- BUG_ON(!list_empty(&lo->plh_layouts));
- NFS_I(lo->plh_inode)->layout = NULL;
- kfree(lo);
- }
+static void
+put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
+{
+ if (atomic_dec_and_test(&lo->plh_refcount))
+ destroy_layout_hdr(lo);
}
void
-put_layout_hdr(struct inode *inode)
+put_layout_hdr(struct pnfs_layout_hdr *lo)
{
- spin_lock(&inode->i_lock);
- put_layout_hdr_locked(NFS_I(inode)->layout);
- spin_unlock(&inode->i_lock);
+ struct inode *inode = lo->plh_inode;
+
+ if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
+ destroy_layout_hdr(lo);
+ spin_unlock(&inode->i_lock);
+ }
}
static void
@@ -223,7 +227,7 @@ static void free_lseg(struct pnfs_layout_segment *lseg)
NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
/* Matched by get_layout_hdr in pnfs_insert_layout */
- put_layout_hdr(ino);
+ put_layout_hdr(NFS_I(ino)->layout);
}
/* The use of tmp_list is necessary because pnfs_curr_ld->free_lseg
@@ -490,7 +494,7 @@ pnfs_insert_layout(struct pnfs_layout_hdr *lo,
__func__, lseg, lseg->pls_range.iomode,
lseg->pls_range.offset, lseg->pls_range.length);
}
- get_layout_hdr_locked(lo);
+ get_layout_hdr(lo);
dprintk("%s:Return\n", __func__);
}
@@ -503,7 +507,7 @@ alloc_init_layout_hdr(struct inode *ino)
lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL);
if (!lo)
return NULL;
- lo->plh_refcount = 1;
+ atomic_set(&lo->plh_refcount, 1);
INIT_LIST_HEAD(&lo->plh_layouts);
INIT_LIST_HEAD(&lo->plh_segs);
lo->plh_inode = ino;
@@ -618,7 +622,7 @@ pnfs_update_layout(struct inode *ino,
goto out_unlock;
atomic_inc(&lo->plh_outstanding);
- get_layout_hdr_locked(lo);
+ get_layout_hdr(lo);
if (list_empty(&lo->plh_segs)) {
/* The lo must be on the clp list if there is any
* chance of a CB_LAYOUTRECALL(FILE) coming in.
@@ -641,7 +645,7 @@ pnfs_update_layout(struct inode *ino,
spin_unlock(&ino->i_lock);
}
atomic_dec(&lo->plh_outstanding);
- put_layout_hdr(ino);
+ put_layout_hdr(lo);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout->plh_flags, lseg);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 698380d..8aaab56 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -65,7 +65,7 @@ struct pnfs_layoutdriver_type {
};
struct pnfs_layout_hdr {
- unsigned long plh_refcount;
+ atomic_t plh_refcount;
struct list_head plh_layouts; /* other client layouts */
struct list_head plh_segs; /* layout segments list */
nfs4_stateid plh_stateid;
@@ -147,7 +147,7 @@ void unset_pnfs_layoutdriver(struct nfs_server *);
int pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
-void put_layout_hdr(struct inode *inode);
+void put_layout_hdr(struct pnfs_layout_hdr *lo);
int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state);
--
1.7.2.1
next prev parent reply other threads:[~2010-12-23 23:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-23 23:54 [PATCH 00/15] pnfs wave 2 submission, try 5 Fred Isaman
2010-12-23 23:54 ` [PATCH 01/15] pnfs: fix incorrect comment in destroy_lseg Fred Isaman
2010-12-23 23:54 ` [PATCH 02/15] pnfs: remove unnecessary field lgp->status Fred Isaman
2010-12-23 23:54 ` [PATCH 03/15] pnfs: add prefix to struct pnfs_layout_segment fields Fred Isaman
2010-12-23 23:54 ` [PATCH 04/15] pnfs: add prefix to struct pnfs_layout_hdr fields Fred Isaman
2010-12-23 23:54 ` [PATCH 05/15] pnfs: change layout state seqlock to a spinlock Fred Isaman
2010-12-23 23:54 ` [PATCH 06/15] pnfs: change how lsegs are removed from layout list Fred Isaman
2010-12-23 23:54 ` [PATCH 07/15] pnfs: layoutget rpc code cleanup Fred Isaman
2010-12-23 23:54 ` [PATCH 08/15] pnfs: serialize LAYOUTGET(openstateid) Fred Isaman
2010-12-23 23:54 ` [PATCH 09/15] pnfs: add layout to client list before sending rpc Fred Isaman
2010-12-23 23:54 ` [PATCH 10/15] pnfs: check that partial LAYOUTGET return is ignored Fred Isaman
2010-12-23 23:54 ` Fred Isaman [this message]
2010-12-23 23:54 ` [PATCH 12/15] pnfs: CB_LAYOUTRECALL xdr code Fred Isaman
2010-12-23 23:54 ` [PATCH 13/15] pnfs: add CB_LAYOUTRECALL handling Fred Isaman
2010-12-23 23:54 ` [PATCH 14/15] pnfs: update nfs4_callback_recallany to handle layouts Fred Isaman
2010-12-23 23:54 ` [PATCH 15/15] pnfs: layout roc code Fred Isaman
-- strict thread matches above, loose matches on Subject: below --
2011-01-06 11:36 [PATCH 00/15] pnfs wave 2 submission Fred Isaman
2011-01-06 11:36 ` [PATCH 11/15] pnfs: change lo refcounting to atomic_t Fred Isaman
2010-12-23 17:29 [PATCH 00/15] pnfs wave 2 submission, try 4 Fred Isaman
2010-12-23 17:29 ` [PATCH 11/15] pnfs: change lo refcounting to atomic_t Fred Isaman
2010-12-23 12:47 [PATCH 00/15] pnfs wave 2 submission, try 3 Fred Isaman
2010-12-23 12:47 ` [PATCH 11/15] pnfs: change lo refcounting to atomic_t Fred Isaman
2010-12-22 4:00 [PATCH 00/15] pnfs wave 2 submission, try 2 Fred Isaman
2010-12-22 4:00 ` [PATCH 11/15] pnfs: change lo refcounting to atomic_t Fred Isaman
2010-12-22 21:47 ` Trond Myklebust
[not found] ` <1293054479.6422.18.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org>
2010-12-22 22:08 ` Fred Isaman
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