[patch 28/28] NFS: Fix an O_DIRECT Oops...

Greg KH
2009-08-13T19:48:14Z

[-- Attachment #1: nfs-fix-an-o_direct-oops.patch --]
[-- Type: text/plain, Size: 6979 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit 1ae88b2e446261c038f2c0c3150ffae142b227a2 upstream.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/nfs/direct.c | 20 ++++++++++----------
fs/nfs/read.c | 6 ++----
fs/nfs/write.c | 6 ++----
include/linux/nfs_fs.h | 5 ++---
4 files changed, 16 insertions(+), 21 deletions(-)

--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -255,7 +255,7 @@ static void nfs_direct_read_release(void

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 = {
@@ -311,14 +311,14 @@ static ssize_t nfs_direct_read_schedule_
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;
@@ -331,7 +331,7 @@ static ssize_t nfs_direct_read_schedule_
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;
@@ -438,7 +438,7 @@ static void nfs_direct_free_writedata(st
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);
}
}

@@ -531,7 +531,7 @@ static void nfs_direct_commit_release(vo

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 = {
@@ -564,7 +564,7 @@ static void nfs_direct_commit_schedule(s
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;
@@ -725,14 +725,14 @@ static ssize_t nfs_direct_write_schedule
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;
@@ -747,7 +747,7 @@ static ssize_t nfs_direct_write_schedule
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;
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -58,17 +58,15 @@ struct nfs_read_data *nfs_readdata_alloc
return p;
}

-static void nfs_readdata_free(struct nfs_read_data *p)
+void nfs_readdata_free(struct nfs_read_data *p)
{
if (p && (p->pagevec != &p->page_array[0]))
kfree(p->pagevec);
mempool_free(p, nfs_rdata_mempool);
}

-void nfs_readdata_release(void *data)
+static void nfs_readdata_release(struct nfs_read_data *rdata)
{
- struct nfs_read_data *rdata = data;
-
put_nfs_open_context(rdata->args.context);
nfs_readdata_free(rdata);
}
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -84,17 +84,15 @@ struct nfs_write_data *nfs_writedata_all
return p;
}

-static void nfs_writedata_free(struct nfs_write_data *p)
+void nfs_writedata_free(struct nfs_write_data *p)
{
if (p && (p->pagevec != &p->page_array[0]))
kfree(p->pagevec);
mempool_free(p, nfs_wdata_mempool);
}

-void nfs_writedata_release(void *data)
+static void nfs_writedata_release(struct nfs_write_data *wdata)
{
- struct nfs_write_data *wdata = data;
-
put_nfs_open_context(wdata->args.context);
nfs_writedata_free(wdata);
}
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -461,7 +461,6 @@ extern int nfs_writepages(struct addres
extern int nfs_flush_incompatible(struct file *file, struct page *page);
extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
-extern void nfs_writedata_release(void *);

/*
* Try to write back everything synchronously (but check the
@@ -476,7 +475,6 @@ extern int nfs_wb_page_cancel(struct ino
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);
-extern void nfs_commitdata_release(void *wdata);
#else
static inline int
nfs_commit_inode(struct inode *inode, int how)
@@ -495,6 +493,7 @@ nfs_have_writebacks(struct inode *inode)
* Allocate nfs_write_data structures
*/
extern struct nfs_write_data *nfs_writedata_alloc(unsigned int npages);
+extern void nfs_writedata_free(struct nfs_write_data *);

/*
* linux/fs/nfs/read.c
@@ -503,12 +502,12 @@ extern int nfs_readpage(struct file *,
extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
extern int nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
-extern void nfs_readdata_release(void *data);

/*
* Allocate nfs_read_data structures
*/
extern struct nfs_read_data *nfs_readdata_alloc(unsigned int npages);
+extern void nfs_readdata_free(struct nfs_read_data *);

/*
* linux/fs/nfs3proc.c