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NFS: O_DIRECT async IO may lose context
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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 <[email protected]>
Trond Myklebust authored and Trond Myklebust committed Mar 20, 2006
1 parent fad6149 commit a8881f5
Showing 1 changed file with 12 additions and 18 deletions.
30 changes: 12 additions & 18 deletions fs/nfs/direct.c
Original file line number Diff line number Diff line change
@@ -71,7 +71,7 @@ struct nfs_direct_req {
/* 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 @@ static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
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 inline struct nfs_direct_req *nfs_direct_req_alloc(void)
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 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq)
} else
wake_up(&dreq->wait);

iput(dreq->inode);
kref_put(&dreq->kref, nfs_direct_req_release);
}

@@ -317,10 +320,8 @@ static const struct rpc_call_ops nfs_read_direct_ops = {
*/
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 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size
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 const struct rpc_call_ops nfs_commit_direct_ops = {

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 const struct rpc_call_ops nfs_write_direct_ops = {
*/
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 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
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;

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