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authorTrond Myklebust <Trond.Myklebust@netapp.com>2010-07-30 15:31:54 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2010-07-30 15:38:42 -0400
commitb608b283a962caaa280756bc8563016a71712acf (patch)
tree217a745ab305219fab676d4a215c1a709004bd57
parent674b2222920012244ca59978b356b25412a8dcc7 (diff)
NFS: kswapd must not block in nfs_release_page
See https://bugzilla.kernel.org/show_bug.cgi?id=16056 If other processes are blocked waiting for kswapd to free up some memory so that they can make progress, then we cannot allow kswapd to block on those processes. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
-rw-r--r--fs/nfs/file.c13
-rw-r--r--fs/nfs/write.c4
-rw-r--r--include/linux/nfs_fs.h1
3 files changed, 14 insertions, 4 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 36a5e74f51b4..f036153d9f50 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -27,6 +27,7 @@
#include <linux/pagemap.h>
#include <linux/aio.h>
#include <linux/gfp.h>
+#include <linux/swap.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -493,11 +494,19 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset)
*/
static int nfs_release_page(struct page *page, gfp_t gfp)
{
+ struct address_space *mapping = page->mapping;
+
dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
/* Only do I/O if gfp is a superset of GFP_KERNEL */
- if ((gfp & GFP_KERNEL) == GFP_KERNEL)
- nfs_wb_page(page->mapping->host, page);
+ if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) {
+ int how = FLUSH_SYNC;
+
+ /* Don't let kswapd deadlock waiting for OOM RPC calls */
+ if (current_is_kswapd())
+ how = 0;
+ nfs_commit_inode(mapping->host, how);
+ }
/* If PagePrivate() is set, then the page is not freeable */
if (PagePrivate(page))
return 0;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 91679e2631ee..0a6c65a1f9d7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1379,7 +1379,7 @@ static const struct rpc_call_ops nfs_commit_ops = {
.rpc_release = nfs_commit_release,
};
-static int nfs_commit_inode(struct inode *inode, int how)
+int nfs_commit_inode(struct inode *inode, int how)
{
LIST_HEAD(head);
int may_wait = how & FLUSH_SYNC;
@@ -1443,7 +1443,7 @@ out_mark_dirty:
return ret;
}
#else
-static int nfs_commit_inode(struct inode *inode, int how)
+int nfs_commit_inode(struct inode *inode, int how)
{
return 0;
}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 77c2ae53431c..f6e2455f13d1 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -493,6 +493,7 @@ extern int nfs_wb_all(struct inode *inode);
extern int nfs_wb_page(struct inode *inode, struct page* page);
extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
+extern int nfs_commit_inode(struct inode *, int);
extern struct nfs_write_data *nfs_commitdata_alloc(void);
extern void nfs_commit_free(struct nfs_write_data *wdata);
#endif