The VFS does not like us holding the 'write_access' lease on a
file for too long. The function 'get_write_access()' gets called on an
inode whenever a struct file is created for writing, and is only
released on the last fput() of that struct file.
NFS caches the struct file in the nfs_page in order to access
the RPC credentials that are cached in the filp->private_data area.
Unfortunately this means that both NFS reads and writes can end up
prolonging the write_access lease beyond the end of the 'sys_close()'.
The following patch changes the NFS code so that it caches the RPC
credentials directly in the nfs_page. The struct file is still kept
around for ordinary writes, in order that we can report asynchronous
write errors in sys_close() via filp->f_error.
Cheers,
Trond
diff -u --recursive --new-file linux-2.4.19-fix_create/fs/nfs/flushd.c linux-2.4.19-fix_put/fs/nfs/flushd.c
--- linux-2.4.19-fix_create/fs/nfs/flushd.c Fri Nov 9 23:28:15 2001
+++ linux-2.4.19-fix_put/fs/nfs/flushd.c Tue Mar 12 15:34:24 2002
@@ -59,7 +59,7 @@
static void nfs_flushd_exit(struct rpc_task *);
-int nfs_reqlist_init(struct nfs_server *server)
+static int nfs_reqlist_init(struct nfs_server *server)
{
struct nfs_reqlist *cache;
struct rpc_task *task;
@@ -136,7 +136,7 @@
init_waitqueue_head(&cache->request_wait);
server->rw_requests = cache;
- return 0;
+ return nfs_reqlist_init(server);
}
void nfs_reqlist_free(struct nfs_server *server)
diff -u --recursive --new-file linux-2.4.19-fix_create/fs/nfs/pagelist.c linux-2.4.19-fix_put/fs/nfs/pagelist.c
--- linux-2.4.19-fix_create/fs/nfs/pagelist.c Fri Dec 21 18:41:55 2001
+++ linux-2.4.19-fix_put/fs/nfs/pagelist.c Tue Mar 12 15:34:24 2002
@@ -53,7 +53,7 @@
/**
* nfs_create_request - Create an NFS read/write request.
- * @file: file that owns this request
+ * @cred: RPC credential to use
* @inode: inode to which the request is attached
* @page: page to write
* @offset: starting offset within the page for the write
@@ -66,7 +66,7 @@
* User should ensure it is safe to sleep in this function.
*/
struct nfs_page *
-nfs_create_request(struct file *file, struct inode *inode,
+nfs_create_request(struct rpc_cred *cred, struct inode *inode,
struct page *page,
unsigned int offset, unsigned int count)
{
@@ -108,34 +108,49 @@
req->wb_offset = offset;
req->wb_bytes = count;
- /* If we have a struct file, use its cached credentials */
- if (file) {
- req->wb_file = file;
- get_file(file);
- req->wb_cred = nfs_file_cred(file);
- }
+ if (cred)
+ req->wb_cred = get_rpccred(cred);
req->wb_inode = inode;
req->wb_count = 1;
return req;
}
+/**
+ * nfs_clear_request - Free up all resources allocated to the request
+ * @req:
+ *
+ * Release all resources associated with a write request after it
+ * has completed.
+ */
+void nfs_clear_request(struct nfs_page *req)
+{
+ /* Release struct file or cached credential */
+ if (req->wb_file) {
+ fput(req->wb_file);
+ req->wb_file = NULL;
+ }
+ if (req->wb_cred) {
+ put_rpccred(req->wb_cred);
+ req->wb_cred = NULL;
+ }
+ if (req->wb_page) {
+ page_cache_release(req->wb_page);
+ req->wb_page = NULL;
+ atomic_dec(&NFS_REQUESTLIST(req->wb_inode)->nr_requests);
+ }
+}
+
/**
* nfs_release_request - Release the count on an NFS read/write request
* @req: request to release
*
- * Release all resources associated with a write request after it
- * has been committed to stable storage
- *
* Note: Should never be called with the spinlock held!
*/
void
nfs_release_request(struct nfs_page *req)
{
- struct inode *inode = req->wb_inode;
- struct nfs_reqlist *cache = NFS_REQUESTLIST(inode);
-
spin_lock(&nfs_wreq_lock);
if (--req->wb_count) {
spin_unlock(&nfs_wreq_lock);
@@ -143,7 +158,6 @@
}
__nfs_del_lru(req);
spin_unlock(&nfs_wreq_lock);
- atomic_dec(&cache->nr_requests);
#ifdef NFS_PARANOIA
if (!list_empty(&req->wb_list))
@@ -152,16 +166,12 @@
BUG();
if (NFS_WBACK_BUSY(req))
BUG();
- if (atomic_read(&cache->nr_requests) < 0)
+ if (atomic_read(&NFS_REQUESTLIST(req->wb_inode)->nr_requests) < 0)
BUG();
#endif
/* Release struct file or cached credential */
- if (req->wb_file)
- fput(req->wb_file);
- else if (req->wb_cred)
- put_rpccred(req->wb_cred);
- page_cache_release(req->wb_page);
+ nfs_clear_request(req);
nfs_page_free(req);
}
@@ -236,7 +246,7 @@
req = nfs_list_entry(head->next);
if (prev) {
- if (req->wb_file != prev->wb_file)
+ if (req->wb_cred != prev->wb_cred)
break;
if (page_index(req->wb_page) != page_index(prev->wb_page)+1)
break;
@@ -270,7 +280,7 @@
{
struct nfs_server *server = NFS_SERVER(req->wb_inode);
struct list_head *pos, *head = req->wb_list_head;
- struct file *file = req->wb_file;
+ struct rpc_cred *cred = req->wb_cred;
unsigned long idx = page_index(req->wb_page) + 1;
int npages = 0;
@@ -291,7 +301,7 @@
break;
if (req->wb_offset != 0)
break;
- if (req->wb_file != file)
+ if (req->wb_cred != cred)
break;
}
return npages;
diff -u --recursive --new-file linux-2.4.19-fix_create/fs/nfs/read.c linux-2.4.19-fix_put/fs/nfs/read.c
--- linux-2.4.19-fix_create/fs/nfs/read.c Mon Feb 25 20:38:09 2002
+++ linux-2.4.19-fix_put/fs/nfs/read.c Tue Mar 12 15:34:24 2002
@@ -168,7 +168,7 @@
{
struct nfs_page *new;
- new = nfs_create_request(file, inode, page, 0, PAGE_CACHE_SIZE);
+ new = nfs_create_request(nfs_file_cred(file), inode, page, 0, PAGE_CACHE_SIZE);
if (IS_ERR(new))
return PTR_ERR(new);
nfs_mark_request_read(new);
@@ -224,8 +224,9 @@
nfs_list_remove_request(req);
SetPageError(page);
UnlockPage(page);
- nfs_unlock_request(req);
+ nfs_clear_request(req);
nfs_release_request(req);
+ nfs_unlock_request(req);
}
}
@@ -431,6 +432,7 @@
(long long)NFS_FILEID(req->wb_inode),
req->wb_bytes,
(long long)(page_offset(page) + req->wb_offset));
+ nfs_clear_request(req);
nfs_release_request(req);
nfs_unlock_request(req);
}
@@ -448,19 +450,9 @@
int
nfs_readpage(struct file *file, struct page *page)
{
- struct inode *inode;
+ struct inode *inode = page->mapping->host;
int error;
- if (!file) {
- struct address_space *mapping = page->mapping;
- if (!mapping)
- BUG();
- inode = mapping->host;
- } else
- inode = file->f_dentry->d_inode;
- if (!inode)
- BUG();
-
dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
page, PAGE_CACHE_SIZE, page->index);
/*
diff -u --recursive --new-file linux-2.4.19-fix_create/fs/nfs/write.c linux-2.4.19-fix_put/fs/nfs/write.c
--- linux-2.4.19-fix_create/fs/nfs/write.c Mon Feb 25 20:38:09 2002
+++ linux-2.4.19-fix_put/fs/nfs/write.c Tue Mar 12 15:34:24 2002
@@ -238,17 +238,11 @@
int
nfs_writepage(struct page *page)
{
- struct inode *inode;
+ struct inode *inode = page->mapping->host;
unsigned long end_index;
unsigned offset = PAGE_CACHE_SIZE;
int err;
- struct address_space *mapping = page->mapping;
- if (!mapping)
- BUG();
- inode = mapping->host;
- if (!inode)
- BUG();
end_index = inode->i_size >> PAGE_CACHE_SHIFT;
/* Ensure we've flushed out any previous writes */
@@ -362,6 +356,7 @@
iput(inode);
} else
spin_unlock(&nfs_wreq_lock);
+ nfs_clear_request(req);
nfs_release_request(req);
}
@@ -688,9 +683,13 @@
}
spin_unlock(&nfs_wreq_lock);
- new = nfs_create_request(file, inode, page, offset, bytes);
+ new = nfs_create_request(nfs_file_cred(file), inode, page, offset, bytes);
if (IS_ERR(new))
return new;
+ if (file) {
+ new->wb_file = file;
+ get_file(file);
+ }
/* If the region is locked, adjust the timeout */
if (region_locked(inode, new))
new->wb_timeout = jiffies + NFS_WRITEBACK_LOCKDELAY;
@@ -768,7 +767,8 @@
int
nfs_flush_incompatible(struct file *file, struct page *page)
{
- struct inode *inode = file->f_dentry->d_inode;
+ struct rpc_cred *cred = nfs_file_cred(file);
+ struct inode *inode = page->mapping->host;
struct nfs_page *req;
int status = 0;
/*
@@ -781,7 +781,7 @@
*/
req = nfs_find_request(inode,page);
if (req) {
- if (req->wb_file != file || req->wb_page != page)
+ if (req->wb_file != file || req->wb_cred != cred || req->wb_page != page)
status = nfs_wb_page(inode, page);
nfs_release_request(req);
}
@@ -798,7 +798,7 @@
nfs_updatepage(struct file *file, struct page *page, unsigned int offset, unsigned int count)
{
struct dentry *dentry = file->f_dentry;
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = page->mapping->host;
struct nfs_page *req;
loff_t end;
int status = 0;
diff -u --recursive --new-file linux-2.4.19-fix_create/include/linux/nfs_flushd.h linux-2.4.19-fix_put/include/linux/nfs_flushd.h
--- linux-2.4.19-fix_create/include/linux/nfs_flushd.h Thu Nov 22 20:47:41 2001
+++ linux-2.4.19-fix_put/include/linux/nfs_flushd.h Tue Mar 12 15:34:24 2002
@@ -32,7 +32,6 @@
*/
extern int nfs_reqlist_alloc(struct nfs_server *);
extern void nfs_reqlist_free(struct nfs_server *);
-extern int nfs_reqlist_init(struct nfs_server *);
extern void nfs_reqlist_exit(struct nfs_server *);
extern void nfs_wake_flushd(void);
diff -u --recursive --new-file linux-2.4.19-fix_create/include/linux/nfs_fs.h linux-2.4.19-fix_put/include/linux/nfs_fs.h
--- linux-2.4.19-fix_create/include/linux/nfs_fs.h Fri Dec 21 18:42:03 2001
+++ linux-2.4.19-fix_put/include/linux/nfs_fs.h Tue Mar 12 15:34:24 2002
@@ -165,7 +165,9 @@
static __inline__ struct rpc_cred *
nfs_file_cred(struct file *file)
{
- struct rpc_cred *cred = (struct rpc_cred *)(file->private_data);
+ struct rpc_cred *cred = NULL;
+ if (file)
+ cred = (struct rpc_cred *)file->private_data;
#ifdef RPC_DEBUG
if (cred && cred->cr_magic != RPCAUTH_CRED_MAGIC)
BUG();
diff -u --recursive --new-file linux-2.4.19-fix_create/include/linux/nfs_page.h linux-2.4.19-fix_put/include/linux/nfs_page.h
--- linux-2.4.19-fix_create/include/linux/nfs_page.h Thu Nov 22 20:47:41 2001
+++ linux-2.4.19-fix_put/include/linux/nfs_page.h Tue Mar 12 15:34:24 2002
@@ -41,9 +41,10 @@
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
-extern struct nfs_page *nfs_create_request(struct file *, struct inode *,
+extern struct nfs_page *nfs_create_request(struct rpc_cred *, struct inode *,
struct page *,
unsigned int, unsigned int);
+extern void nfs_clear_request(struct nfs_page *req);
extern void nfs_release_request(struct nfs_page *req);
-
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