2014-02-07 20:02 GMT+04:00 Jeff Layton <jlayton@xxxxxxxxxx>:
> In the event that a send fails in an uncached write, or we end up
> needing to reissue it (-EAGAIN case), we'll kfree the wdata but
> the pages currently leak.
>
> Fix this by adding a new kref release routine for uncached writedata
> that releases the pages, and have the uncached codepaths use that.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/cifs/cifsglob.h | 2 +-
> fs/cifs/cifsproto.h | 2 +-
> fs/cifs/cifssmb.c | 6 +++---
> fs/cifs/file.c | 28 +++++++++++++++++-----------
> fs/cifs/smb2pdu.c | 4 ++--
> fs/cifs/smb2proto.h | 2 +-
> 6 files changed, 25 insertions(+), 19 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index a245d1809ed8..57d07e704d97 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -323,7 +323,7 @@ struct smb_version_operations {
> /* async read from the server */
> int (*async_readv)(struct cifs_readdata *);
> /* async write to the server */
> - int (*async_writev)(struct cifs_writedata *);
> + int (*async_writev)(struct cifs_writedata *, void (*release)(struct kref *));
> /* sync read from the server */
> int (*sync_read)(const unsigned int, struct cifsFileInfo *,
> struct cifs_io_parms *, unsigned int *, char **,
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index 79e6e9a93a8c..a4f90c0d9950 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -488,7 +488,7 @@ void cifs_readdata_release(struct kref *refcount);
> int cifs_async_readv(struct cifs_readdata *rdata);
> int cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid);
>
> -int cifs_async_writev(struct cifs_writedata *wdata);
> +int cifs_async_writev(struct cifs_writedata *wdata, void (*release)(struct kref *kref));
> void cifs_writev_complete(struct work_struct *work);
> struct cifs_writedata *cifs_writedata_alloc(unsigned int nr_pages,
> work_func_t complete);
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index 4d881c35eeca..0726ab413b8c 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -1910,7 +1910,7 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
>
> do {
> server = tlink_tcon(wdata->cfile->tlink)->ses->server;
> - rc = server->ops->async_writev(wdata);
> + rc = server->ops->async_writev(wdata, cifs_writedata_release);
> } while (rc == -EAGAIN);
>
> for (i = 0; i < wdata->nr_pages; i++) {
> @@ -2031,7 +2031,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
>
> /* cifs_async_writev - send an async write, and set up mid to handle result */
> int
> -cifs_async_writev(struct cifs_writedata *wdata)
> +cifs_async_writev(struct cifs_writedata *wdata, void (*release)(struct kref *kref))
> {
> int rc = -EACCES;
> WRITE_REQ *smb = NULL;
> @@ -2105,7 +2105,7 @@ cifs_async_writev(struct cifs_writedata *wdata)
> if (rc == 0)
> cifs_stats_inc(&tcon->stats.cifs_stats.num_writes);
> else
> - kref_put(&wdata->refcount, cifs_writedata_release);
> + kref_put(&wdata->refcount, release);
>
> async_writev_out:
> cifs_small_buf_release(smb);
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 853d6d1cc822..03d1f454c713 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -2043,7 +2043,7 @@ retry:
> }
> wdata->pid = wdata->cfile->pid;
> server = tlink_tcon(wdata->cfile->tlink)->ses->server;
> - rc = server->ops->async_writev(wdata);
> + rc = server->ops->async_writev(wdata, cifs_writedata_release);
> } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN);
>
> for (i = 0; i < nr_pages; ++i)
> @@ -2331,9 +2331,20 @@ size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
> }
>
> static void
> -cifs_uncached_writev_complete(struct work_struct *work)
> +cifs_uncached_writedata_release(struct kref *refcount)
> {
> int i;
> + struct cifs_writedata *wdata = container_of(refcount,
> + struct cifs_writedata, refcount);
> +
> + for (i = 0; i < wdata->nr_pages; i++)
> + put_page(wdata->pages[i]);
> + cifs_writedata_release(refcount);
> +}
> +
> +static void
> +cifs_uncached_writev_complete(struct work_struct *work)
> +{
> struct cifs_writedata *wdata = container_of(work,
> struct cifs_writedata, work);
> struct inode *inode = wdata->cfile->dentry->d_inode;
> @@ -2347,12 +2358,7 @@ cifs_uncached_writev_complete(struct work_struct *work)
>
> complete(&wdata->done);
>
> - if (wdata->result != -EAGAIN) {
> - for (i = 0; i < wdata->nr_pages; i++)
> - put_page(wdata->pages[i]);
> - }
> -
> - kref_put(&wdata->refcount, cifs_writedata_release);
> + kref_put(&wdata->refcount, cifs_uncached_writedata_release);
> }
>
> /* attempt to send write to server, retry on any -EAGAIN errors */
> @@ -2370,7 +2376,7 @@ cifs_uncached_retry_writev(struct cifs_writedata *wdata)
> if (rc != 0)
> continue;
> }
> - rc = server->ops->async_writev(wdata);
> + rc = server->ops->async_writev(wdata, cifs_uncached_writedata_release);
> } while (rc == -EAGAIN);
>
> return rc;
> @@ -2454,7 +2460,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
> wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
> rc = cifs_uncached_retry_writev(wdata);
> if (rc) {
> - kref_put(&wdata->refcount, cifs_writedata_release);
> + kref_put(&wdata->refcount, cifs_uncached_writedata_release);
> break;
> }
>
> @@ -2496,7 +2502,7 @@ restart_loop:
> }
> }
> list_del_init(&wdata->list);
> - kref_put(&wdata->refcount, cifs_writedata_release);
> + kref_put(&wdata->refcount, cifs_uncached_writedata_release);
> }
>
> if (total_written > 0)
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 2013234b73ad..8c04bdeda136 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -1890,7 +1890,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
>
> /* smb2_async_writev - send an async write, and set up mid to handle result */
> int
> -smb2_async_writev(struct cifs_writedata *wdata)
> +smb2_async_writev(struct cifs_writedata *wdata, void (*release)(struct kref *kref))
> {
> int rc = -EACCES;
> struct smb2_write_req *req = NULL;
> @@ -1938,7 +1938,7 @@ smb2_async_writev(struct cifs_writedata *wdata)
> smb2_writev_callback, wdata, 0);
>
> if (rc) {
> - kref_put(&wdata->refcount, cifs_writedata_release);
> + kref_put(&wdata->refcount, release);
> cifs_stats_fail_inc(tcon, SMB2_WRITE_HE);
> }
>
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index 93adc64666f3..1833724542cd 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -123,7 +123,7 @@ extern int SMB2_get_srv_num(const unsigned int xid, struct cifs_tcon *tcon,
> extern int smb2_async_readv(struct cifs_readdata *rdata);
> extern int SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
> unsigned int *nbytes, char **buf, int *buf_type);
> -extern int smb2_async_writev(struct cifs_writedata *wdata);
> +extern int smb2_async_writev(struct cifs_writedata *wdata, void (*release)(struct kref *kref));
> extern int SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
> unsigned int *nbytes, struct kvec *iov, int n_vec);
> extern int SMB2_echo(struct TCP_Server_Info *server);
> --
> 1.8.5.3
>
> --
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Reviewed-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
--
Best regards,
Pavel Shilovsky.
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