kvm tools, 9p: Add error handling to protocol handlers

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
index d9276889712d5e079bd869d1a7fedb59a0e1e1e8..e7e108bd508941e5105dcdaf2f75a2d1365a27b3 100644 (file)
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -236,6 +236,9 @@ err_out:
 static void virtio_p9_create(struct p9_dev *p9dev,
                             struct p9_pdu *pdu, u32 *outlen)
 {
+       DIR *dir;
+       int fd;
+       int res;
        u8 mode;
        u32 perm;
        char *name;
@@ -243,24 +246,33 @@ static void virtio_p9_create(struct p9_dev *p9dev,
        struct stat st;
        struct p9_qid qid;
        struct p9_fid *fid;
+       char full_path[PATH_MAX];
 
        virtio_p9_pdu_readf(pdu, "dsdb", &fid_val, &name, &perm, &mode);
        fid = &p9dev->fids[fid_val];
 
-       sprintf(fid->path, "%s/%.*s", fid->path, (int)strlen(name), name);
-       close_fid(p9dev, fid_val);
-
+       sprintf(full_path, "%s/%s", fid->abs_path, name);
        if (perm & P9_DMDIR) {
-               mkdir(fid->abs_path, perm & 0xFFFF);
-               fid->dir = opendir(fid->abs_path);
+               res = mkdir(full_path, perm & 0xFFFF);
+               if (res < 0)
+                       goto err_out;
+               dir = opendir(full_path);
+               if (!dir)
+                       goto err_out;
+               close_fid(p9dev, fid_val);
+               fid->dir = dir;
                fid->is_dir = 1;
        } else {
-               fid->fd = open(fid->abs_path,
-                              omode2uflags(mode) | O_CREAT, 0777);
+               fd = open(full_path, omode2uflags(mode) | O_CREAT, 0777);
+               if (fd < 0)
+                       goto err_out;
+               close_fid(p9dev, fid_val);
+               fid->fd = fd;
        }
-       if (lstat(fid->abs_path, &st) < 0)
+       if (lstat(full_path, &st) < 0)
                goto err_out;
 
+       sprintf(fid->path, "%s/%s", fid->path, name);
        st2qid(&st, &qid);
        virtio_p9_pdu_writef(pdu, "Qd", &qid, 0);
        *outlen = pdu->write_offset;
@@ -493,12 +505,16 @@ static void virtio_p9_wstat(struct p9_dev *p9dev,
        virtio_p9_pdu_readf(pdu, "dwS", &fid_val, &unused, &wstat);
        fid = &p9dev->fids[fid_val];
 
-       if (wstat.length != -1UL)
+       if (wstat.length != -1UL) {
                res = ftruncate(fid->fd, wstat.length);
-
-       if (wstat.mode != -1U)
-               chmod(fid->abs_path, wstat.mode & 0xFFFF);
-
+               if (res < 0)
+                       goto err_out;
+       }
+       if (wstat.mode != -1U) {
+               res = chmod(fid->abs_path, wstat.mode & 0xFFFF);
+               if (res < 0)
+                       goto err_out;
+       }
        if (strlen(wstat.name) > 0) {
                char new_name[PATH_MAX] = {0};
                char full_path[PATH_MAX];
@@ -512,17 +528,24 @@ static void virtio_p9_wstat(struct p9_dev *p9dev,
                       wstat.name, strlen(wstat.name));
 
                /* fid is reused for the new file */
-               rename(fid->abs_path, rel_to_abs(p9dev, new_name, full_path));
+               res = rename(fid->abs_path,
+                            rel_to_abs(p9dev, new_name, full_path));
+               if (res < 0)
+                       goto err_out;
                sprintf(fid->path, "%s", new_name);
        }
        *outlen = VIRTIO_P9_HDR_LEN;
        virtio_p9_set_reply_header(pdu, *outlen);
        return;
+err_out:
+       virtio_p9_error_reply(p9dev, pdu, errno, outlen);
+       return;
 }
 
 static void virtio_p9_remove(struct p9_dev *p9dev,
                             struct p9_pdu *pdu, u32 *outlen)
 {
+       int res;
        u32 fid_val;
        struct p9_fid *fid;
 
@@ -530,21 +553,28 @@ static void virtio_p9_remove(struct p9_dev *p9dev,
        fid = &p9dev->fids[fid_val];
        close_fid(p9dev, fid_val);
        if (fid->is_dir)
-               rmdir(fid->abs_path);
+               res = rmdir(fid->abs_path);
        else
-               unlink(fid->abs_path);
+               res = unlink(fid->abs_path);
+       if (res < 0)
+               goto err_out;
 
        *outlen = VIRTIO_P9_HDR_LEN;
        virtio_p9_set_reply_header(pdu, *outlen);
        return;
+err_out:
+       virtio_p9_error_reply(p9dev, pdu, errno, outlen);
+       return;
 }
 
 static void virtio_p9_write(struct p9_dev *p9dev,
                            struct p9_pdu *pdu, u32 *outlen)
 {
+
        u64 offset;
        u32 fid_val;
-       u32 count, rcount;
+       u32 count;
+       ssize_t res;
        struct p9_fid *fid;
 
        virtio_p9_pdu_readf(pdu, "dqd", &fid_val, &offset, &count);
@@ -557,11 +587,16 @@ static void virtio_p9_write(struct p9_dev *p9dev,
                                     sizeof(struct p9_twrite));
        pdu->out_iov_cnt = virtio_p9_update_iov_cnt(pdu->out_iov, count,
                                                    pdu->out_iov_cnt);
-       rcount = pwritev(fid->fd, pdu->out_iov, pdu->out_iov_cnt, offset);
-       virtio_p9_pdu_writef(pdu, "d", rcount);
+       res = pwritev(fid->fd, pdu->out_iov, pdu->out_iov_cnt, offset);
+       if (res < 0)
+               goto err_out;
+       virtio_p9_pdu_writef(pdu, "d", res);
        *outlen = pdu->write_offset;
        virtio_p9_set_reply_header(pdu, *outlen);
        return;
+err_out:
+       virtio_p9_error_reply(p9dev, pdu, errno, outlen);
+       return;
 }
 
 typedef void p9_handler(struct p9_dev *p9dev,