NFS: O_DIRECT async IO may lose context
The struct nfs_direct_req currently keeps a pointer to the file descriptor
without referencing it. This may cause problems if the parent process is
killed.
The nfs_open_context should normally have all the information that we're
currently using the filp for, and unlike fput(), is safe to release from
an rpciod process context.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index f0f2053..e6585b9 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -71,7 +71,7 @@
/* I/O parameters */
struct list_head list, /* nfs_read/write_data structs */
rewrite_list; /* saved nfs_write_data structs */
- struct file * filp; /* file descriptor */
+ struct nfs_open_context *ctx; /* file open context info */
struct kiocb * iocb; /* controlling i/o request */
wait_queue_head_t wait; /* wait for i/o completion */
struct inode * inode; /* target file of i/o */
@@ -176,6 +176,7 @@
INIT_LIST_HEAD(&dreq->list);
INIT_LIST_HEAD(&dreq->rewrite_list);
dreq->iocb = NULL;
+ dreq->ctx = NULL;
spin_lock_init(&dreq->lock);
dreq->outstanding = 0;
dreq->count = 0;
@@ -188,6 +189,9 @@
static void nfs_direct_req_release(struct kref *kref)
{
struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref);
+
+ if (dreq->ctx != NULL)
+ put_nfs_open_context(dreq->ctx);
kmem_cache_free(nfs_direct_cachep, dreq);
}
@@ -235,7 +239,6 @@
} else
wake_up(&dreq->wait);
- iput(dreq->inode);
kref_put(&dreq->kref, nfs_direct_req_release);
}
@@ -317,10 +320,8 @@
*/
static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
{
- struct file *file = dreq->filp;
- struct inode *inode = file->f_mapping->host;
- struct nfs_open_context *ctx = (struct nfs_open_context *)
- file->private_data;
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = ctx->dentry->d_inode;
struct list_head *list = &dreq->list;
struct page **pages = dreq->pages;
size_t count = dreq->user_count;
@@ -396,9 +397,8 @@
dreq->pos = pos;
dreq->pages = pages;
dreq->npages = nr_pages;
- igrab(inode);
dreq->inode = inode;
- dreq->filp = iocb->ki_filp;
+ dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
@@ -462,14 +462,11 @@
static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
{
- struct file *file = dreq->filp;
- struct nfs_open_context *ctx = (struct nfs_open_context *)
- file->private_data;
struct nfs_write_data *data = dreq->commit_data;
struct rpc_task *task = &data->task;
data->inode = dreq->inode;
- data->cred = ctx->cred;
+ data->cred = dreq->ctx->cred;
data->args.fh = NFS_FH(data->inode);
data->args.offset = dreq->pos;
@@ -641,10 +638,8 @@
*/
static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
{
- struct file *file = dreq->filp;
- struct inode *inode = file->f_mapping->host;
- struct nfs_open_context *ctx = (struct nfs_open_context *)
- file->private_data;
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = ctx->dentry->d_inode;
struct list_head *list = &dreq->list;
struct page **pages = dreq->pages;
size_t count = dreq->user_count;
@@ -725,9 +720,8 @@
dreq->pos = pos;
dreq->pages = pages;
dreq->npages = nr_pages;
- igrab(inode);
dreq->inode = inode;
- dreq->filp = iocb->ki_filp;
+ dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;