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[CIFS] clean up page array when uncached write send fails
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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.

[original patch by Jeff modified to fix minor formatting problems]

Signed-off-by: Jeff Layton <[email protected]>
Reviewed-by: Pavel Shilovsky <[email protected]>
Signed-off-by: Steve French <[email protected]>
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@smfrench
smfrench committed Feb 8, 2014
1 parent 26c8f0d commit 4a5c80d
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Showing 6 changed files with 33 additions and 19 deletions.
3 changes: 2 additions & 1 deletion fs/cifs/cifsglob.h
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Original file line number Diff line number Diff line change
Expand Up @@ -323,7 +323,8 @@ 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 **,
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3 changes: 2 additions & 1 deletion fs/cifs/cifsproto.h
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Original file line number Diff line number Diff line change
Expand Up @@ -488,7 +488,8 @@ 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);
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7 changes: 4 additions & 3 deletions fs/cifs/cifssmb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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++) {
Expand Down Expand Up @@ -2025,7 +2025,8 @@ 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;
Expand Down Expand Up @@ -2099,7 +2100,7 @@ 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);
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31 changes: 20 additions & 11 deletions fs/cifs/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2043,7 +2043,8 @@ static int cifs_writepages(struct address_space *mapping,
}
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)
Expand Down Expand Up @@ -2331,9 +2332,20 @@ 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;
Expand All @@ -2347,12 +2359,7 @@ 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 */
Expand All @@ -2370,7 +2377,8 @@ 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;
Expand Down Expand Up @@ -2454,7 +2462,8 @@ 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;
}

Expand Down Expand Up @@ -2496,7 +2505,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
}
}
list_del_init(&wdata->list);
kref_put(&wdata->refcount, cifs_writedata_release);
kref_put(&wdata->refcount, cifs_uncached_writedata_release);
}

if (total_written > 0)
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5 changes: 3 additions & 2 deletions fs/cifs/smb2pdu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1890,7 +1890,8 @@ 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;
Expand Down Expand Up @@ -1938,7 +1939,7 @@ 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);
}

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3 changes: 2 additions & 1 deletion fs/cifs/smb2proto.h
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Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,8 @@ 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);
Expand Down

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