commit 1ae88b2e446261c038f2c0c3150ffae142b227a2
author Trond Myklebust <Trond.Myklebust@netapp.com> Wed Aug 12 09:12:30 2009 -0400
committer Linus Torvalds <torvalds@linux-foundation.org> Wed Aug 12 08:21:39 2009 -0700
tree b3c9c11e4391c59086308e2674661688db5b12f5
parent 7cb7beb31aa3d941833b6a6e553687422c31e4b6

NFS: Fix an O_DIRECT Oops...

We can't call nfs_readdata_release()/nfs_writedata_release() without
first initialising and referencing args.context. Doing so inside
nfs_direct_read_schedule_segment()/nfs_direct_write_schedule_segment()
causes an Oops.

We should rather be calling nfs_readdata_free()/nfs_writedata_free() in
those cases.

Looking at the O_DIRECT code, the "struct nfs_direct_req" is already
referencing the nfs_open_context for us. Since the readdata and writedata
structures carry a reference to that, we can simplify things by getting rid
of the extra nfs_open_context references, so that we can replace all
instances of nfs_readdata_release()/nfs_writedata_release().

Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfs/direct.c

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 489fc01..e4e089a 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -255,7 +255,7 @@
 
 	if (put_dreq(dreq))
 		nfs_direct_complete(dreq);
-	nfs_readdata_release(calldata);
+	nfs_readdata_free(data);
 }
 
 static const struct rpc_call_ops nfs_read_direct_ops = {
@@ -314,14 +314,14 @@
 					data->npages, 1, 0, data->pagevec, NULL);
 		up_read(&current->mm->mmap_sem);
 		if (result < 0) {
-			nfs_readdata_release(data);
+			nfs_readdata_free(data);
 			break;
 		}
 		if ((unsigned)result < data->npages) {
 			bytes = result * PAGE_SIZE;
 			if (bytes <= pgbase) {
 				nfs_direct_release_pages(data->pagevec, result);
-				nfs_readdata_release(data);
+				nfs_readdata_free(data);
 				break;
 			}
 			bytes -= pgbase;
@@ -334,7 +334,7 @@
 		data->inode = inode;
 		data->cred = msg.rpc_cred;
 		data->args.fh = NFS_FH(inode);
-		data->args.context = get_nfs_open_context(ctx);
+		data->args.context = ctx;
 		data->args.offset = pos;
 		data->args.pgbase = pgbase;
 		data->args.pages = data->pagevec;
@@ -441,7 +441,7 @@
 		struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages);
 		list_del(&data->pages);
 		nfs_direct_release_pages(data->pagevec, data->npages);
-		nfs_writedata_release(data);
+		nfs_writedata_free(data);
 	}
 }
 
@@ -534,7 +534,7 @@
 
 	dprintk("NFS: %5u commit returned %d\n", data->task.tk_pid, status);
 	nfs_direct_write_complete(dreq, data->inode);
-	nfs_commitdata_release(calldata);
+	nfs_commit_free(data);
 }
 
 static const struct rpc_call_ops nfs_commit_direct_ops = {
@@ -570,7 +570,7 @@
 	data->args.fh = NFS_FH(data->inode);
 	data->args.offset = 0;
 	data->args.count = 0;
-	data->args.context = get_nfs_open_context(dreq->ctx);
+	data->args.context = dreq->ctx;
 	data->res.count = 0;
 	data->res.fattr = &data->fattr;
 	data->res.verf = &data->verf;
@@ -734,14 +734,14 @@
 					data->npages, 0, 0, data->pagevec, NULL);
 		up_read(&current->mm->mmap_sem);
 		if (result < 0) {
-			nfs_writedata_release(data);
+			nfs_writedata_free(data);
 			break;
 		}
 		if ((unsigned)result < data->npages) {
 			bytes = result * PAGE_SIZE;
 			if (bytes <= pgbase) {
 				nfs_direct_release_pages(data->pagevec, result);
-				nfs_writedata_release(data);
+				nfs_writedata_free(data);
 				break;
 			}
 			bytes -= pgbase;
@@ -756,7 +756,7 @@
 		data->inode = inode;
 		data->cred = msg.rpc_cred;
 		data->args.fh = NFS_FH(inode);
-		data->args.context = get_nfs_open_context(ctx);
+		data->args.context = ctx;
 		data->args.offset = pos;
 		data->args.pgbase = pgbase;
 		data->args.pages = data->pagevec;