Commit 597b027f authored by Jeff Layton's avatar Jeff Layton
Browse files

cifs: call cifs_update_eof with i_lock held 



cifs_update_eof has the potential to be racy if multiple threads are
trying to modify it at the same time. Protect modifications of the
server_eof value with the inode->i_lock.

Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
parent e9492871

fs/cifs/cifsglob.h

+1 −1
Original line number Diff line number Diff line
@@ -626,7 +626,7 @@ struct cifsInodeInfo { 
	bool delete_pending;		/* DELETE_ON_CLOSE is set */

	bool invalid_mapping;		/* pagecache is invalid */

	unsigned long time;		/* jiffies of last update of inode */

	u64  server_eof;		/* current file size on server */

	u64  server_eof;		/* current file size on server -- protected by i_lock */

	u64  uniqueid;			/* server inode number */

	u64  createtime;		/* creation time on server */

#ifdef CONFIG_CIFS_FSCACHE

fs/cifs/cifssmb.c

+2 −0
Original line number Diff line number Diff line
@@ -2044,7 +2044,9 @@ cifs_writev_complete(struct work_struct *work) 
	int i = 0;



	if (wdata->result == 0) {

		spin_lock(&inode->i_lock);

		cifs_update_eof(CIFS_I(inode), wdata->offset, wdata->bytes);

		spin_unlock(&inode->i_lock);

		cifs_stats_bytes_written(tlink_tcon(wdata->cfile->tlink),

					 wdata->bytes);

	} else if (wdata->sync_mode == WB_SYNC_ALL && wdata->result == -EAGAIN)

fs/cifs/file.c

+8 −1
Original line number Diff line number Diff line
@@ -1399,7 +1399,10 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *flock) 
	return rc;

}



/* update the file size (if needed) after a write */

/*

 * update the file size (if needed) after a write. Should be called with

 * the inode->i_lock held

 */

void

cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,

		      unsigned int bytes_written)
@@ -1471,7 +1474,9 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid, 
				return rc;

			}

		} else {

			spin_lock(&dentry->d_inode->i_lock);

			cifs_update_eof(cifsi, *poffset, bytes_written);

			spin_unlock(&dentry->d_inode->i_lock);

			*poffset += bytes_written;

		}

	}
@@ -2197,7 +2202,9 @@ cifs_iovec_write(struct file *file, const struct iovec *iov, 
		if (written) {

			len -= written;

			total_written += written;

			spin_lock(&inode->i_lock);

			cifs_update_eof(CIFS_I(inode), *poffset, written);

			spin_unlock(&inode->i_lock);

			*poffset += written;

		} else if (rc < 0) {

			if (!total_written)