1 files changed, 116 insertions, 112 deletions

diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 1b2fc5dfb..b3fc3d088 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -23,6 +23,7 @@
 #include "virtio-9p-xattr.h"
 #include "virtio-9p-coth.h"
 #include "trace.h"
+#include "migration.h"
 
 int open_fd_hw;
 int total_open_fd;
@@ -373,6 +374,19 @@ static void put_fid(V9fsPDU *pdu, V9fsFidState *fidp)
      * Don't free the fid if it is in reclaim list
      */
     if (!fidp->ref && fidp->clunked) {
+        if (fidp->fid == pdu->s->root_fid) {
+            /*
+             * if the clunked fid is root fid then we
+             * have unmounted the fs on the client side.
+             * delete the migration blocker. Ideally, this
+             * should be hooked to transport close notification
+             */
+            if (pdu->s->migration_blocker) {
+                migrate_del_blocker(pdu->s->migration_blocker);
+                error_free(pdu->s->migration_blocker);
+                pdu->s->migration_blocker = NULL;
+            }
+        }
         free_fid(pdu, fidp);
     }
 }
@@ -509,6 +523,30 @@ static int v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path)
     return 0;
 }
 
+static void virtfs_reset(V9fsPDU *pdu)
+{
+    V9fsState *s = pdu->s;
+    V9fsFidState *fidp = NULL;
+
+    /* Free all fids */
+    while (s->fid_list) {
+        fidp = s->fid_list;
+        s->fid_list = fidp->next;
+
+        if (fidp->ref) {
+            fidp->clunked = 1;
+        } else {
+            free_fid(pdu, fidp);
+        }
+    }
+    if (fidp) {
+        /* One or more unclunked fids found... */
+        error_report("9pfs:%s: One or more uncluncked fids "
+                     "found during reset", __func__);
+    }
+    return;
+}
+
 #define P9_QID_TYPE_DIR         0x80
 #define P9_QID_TYPE_SYMLINK     0x02
 
@@ -636,40 +674,6 @@ static size_t pdu_pack(V9fsPDU *pdu, size_t offset, const void *src,
                              offset, size, 1);
 }
 
-static int pdu_copy_sg(V9fsPDU *pdu, size_t offset, int rx, struct iovec *sg)
-{
-    size_t pos = 0;
-    int i, j;
-    struct iovec *src_sg;
-    unsigned int num;
-
-    if (rx) {
-        src_sg = pdu->elem.in_sg;
-        num = pdu->elem.in_num;
-    } else {
-        src_sg = pdu->elem.out_sg;
-        num = pdu->elem.out_num;
-    }
-
-    j = 0;
-    for (i = 0; i < num; i++) {
-        if (offset <= pos) {
-            sg[j].iov_base = src_sg[i].iov_base;
-            sg[j].iov_len = src_sg[i].iov_len;
-            j++;
-        } else if (offset < (src_sg[i].iov_len + pos)) {
-            sg[j].iov_base = src_sg[i].iov_base;
-            sg[j].iov_len = src_sg[i].iov_len;
-            sg[j].iov_base += (offset - pos);
-            sg[j].iov_len -= (offset - pos);
-            j++;
-        }
-        pos += src_sg[i].iov_len;
-    }
-
-    return j;
-}
-
 static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
 {
     size_t old_offset = offset;
@@ -705,12 +709,6 @@ static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
             *valp = le64_to_cpu(val);
             break;
         }
-        case 'v': {
-            struct iovec *iov = va_arg(ap, struct iovec *);
-            int *iovcnt = va_arg(ap, int *);
-            *iovcnt = pdu_copy_sg(pdu, offset, 0, iov);
-            break;
-        }
         case 's': {
             V9fsString *str = va_arg(ap, V9fsString *);
             offset += pdu_unmarshal(pdu, offset, "w", &str->size);
@@ -789,12 +787,6 @@ static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
             offset += pdu_pack(pdu, offset, &val, sizeof(val));
             break;
         }
-        case 'v': {
-            struct iovec *iov = va_arg(ap, struct iovec *);
-            int *iovcnt = va_arg(ap, int *);
-            *iovcnt = pdu_copy_sg(pdu, offset, 1, iov);
-            break;
-        }
         case 's': {
             V9fsString *str = va_arg(ap, V9fsString *);
             offset += pdu_marshal(pdu, offset, "w", str->size);
@@ -1105,42 +1097,6 @@ static void stat_to_v9stat_dotl(V9fsState *s, const struct stat *stbuf,
     stat_to_qid(stbuf, &v9lstat->qid);
 }
 
-static struct iovec *adjust_sg(struct iovec *sg, int len, int *iovcnt)
-{
-    while (len && *iovcnt) {
-        if (len < sg->iov_len) {
-            sg->iov_len -= len;
-            sg->iov_base += len;
-            len = 0;
-        } else {
-            len -= sg->iov_len;
-            sg++;
-            *iovcnt -= 1;
-        }
-    }
-
-    return sg;
-}
-
-static struct iovec *cap_sg(struct iovec *sg, int cap, int *cnt)
-{
-    int i;
-    int total = 0;
-
-    for (i = 0; i < *cnt; i++) {
-        if ((total + sg[i].iov_len) > cap) {
-            sg[i].iov_len -= ((total + sg[i].iov_len) - cap);
-            i++;
-            break;
-        }
-        total += sg[i].iov_len;
-    }
-
-    *cnt = i;
-
-    return sg;
-}
-
 static void print_sg(struct iovec *sg, int cnt)
 {
     int i;
@@ -1182,6 +1138,8 @@ static void v9fs_version(void *opaque)
     pdu_unmarshal(pdu, offset, "ds", &s->msize, &version);
     trace_v9fs_version(pdu->tag, pdu->id, s->msize, version.data);
 
+    virtfs_reset(pdu);
+
     if (!strcmp(version.data, "9P2000.u")) {
         s->proto_version = V9FS_PROTO_2000U;
     } else if (!strcmp(version.data, "9P2000.L")) {
@@ -1235,6 +1193,11 @@ static void v9fs_attach(void *opaque)
     err = offset;
     trace_v9fs_attach_return(pdu->tag, pdu->id,
                              qid.type, qid.version, qid.path);
+    s->root_fid = fid;
+    /* disable migration */
+    error_set(&s->migration_blocker, QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
+              s->ctx.fs_root, s->tag);
+    migrate_add_blocker(s->migration_blocker);
 out:
     put_fid(pdu, fidp);
 out_nofid:
@@ -1731,8 +1694,8 @@ out_nofid:
     complete_pdu(s, pdu, err);
 }
 
-static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu,
-                           V9fsFidState *fidp, int64_t off, int32_t max_count)
+static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp,
+                           uint64_t off, uint32_t max_count)
 {
     size_t offset = 7;
     int read_count;
@@ -1756,7 +1719,7 @@ static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu,
 }
 
 static int v9fs_do_readdir_with_stat(V9fsPDU *pdu,
-                                     V9fsFidState *fidp, int32_t max_count)
+                                     V9fsFidState *fidp, uint32_t max_count)
 {
     V9fsPath path;
     V9fsStat v9stat;
@@ -1816,14 +1779,46 @@ out:
     return count;
 }
 
+/*
+ * Create a QEMUIOVector for a sub-region of PDU iovecs
+ *
+ * @qiov:       uninitialized QEMUIOVector
+ * @skip:       number of bytes to skip from beginning of PDU
+ * @size:       number of bytes to include
+ * @is_write:   true - write, false - read
+ *
+ * The resulting QEMUIOVector has heap-allocated iovecs and must be cleaned up
+ * with qemu_iovec_destroy().
+ */
+static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu,
+                                    uint64_t skip, size_t size,
+                                    bool is_write)
+{
+    QEMUIOVector elem;
+    struct iovec *iov;
+    unsigned int niov;
+
+    if (is_write) {
+        iov = pdu->elem.out_sg;
+        niov = pdu->elem.out_num;
+    } else {
+        iov = pdu->elem.in_sg;
+        niov = pdu->elem.in_num;
+    }
+
+    qemu_iovec_init_external(&elem, iov, niov);
+    qemu_iovec_init(qiov, niov);
+    qemu_iovec_copy(qiov, &elem, skip, size);
+}
+
 static void v9fs_read(void *opaque)
 {
     int32_t fid;
-    int64_t off;
+    uint64_t off;
     ssize_t err = 0;
     int32_t count = 0;
     size_t offset = 7;
-    int32_t max_count;
+    uint32_t max_count;
     V9fsFidState *fidp;
     V9fsPDU *pdu = opaque;
     V9fsState *s = pdu->s;
@@ -1850,21 +1845,21 @@ static void v9fs_read(void *opaque)
         err += pdu_marshal(pdu, offset, "d", count);
         err += count;
     } else if (fidp->fid_type == P9_FID_FILE) {
-        int32_t cnt;
+        QEMUIOVector qiov_full;
+        QEMUIOVector qiov;
         int32_t len;
-        struct iovec *sg;
-        struct iovec iov[128]; /* FIXME: bad, bad, bad */
 
-        sg = iov;
-        pdu_marshal(pdu, offset + 4, "v", sg, &cnt);
-        sg = cap_sg(sg, max_count, &cnt);
+        v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset + 4, max_count, false);
+        qemu_iovec_init(&qiov, qiov_full.niov);
         do {
+            qemu_iovec_reset(&qiov);
+            qemu_iovec_copy(&qiov, &qiov_full, count, qiov_full.size - count);
             if (0) {
-                print_sg(sg, cnt);
+                print_sg(qiov.iov, qiov.niov);
             }
             /* Loop in case of EINTR */
             do {
-                len = v9fs_co_preadv(pdu, fidp, sg, cnt, off);
+                len = v9fs_co_preadv(pdu, fidp, qiov.iov, qiov.niov, off);
                 if (len >= 0) {
                     off   += len;
                     count += len;
@@ -1875,11 +1870,12 @@ static void v9fs_read(void *opaque)
                 err = len;
                 goto out;
             }
-            sg = adjust_sg(sg, len, &cnt);
         } while (count < max_count && len > 0);
         err = offset;
         err += pdu_marshal(pdu, offset, "d", count);
         err += count;
+        qemu_iovec_destroy(&qiov);
+        qemu_iovec_destroy(&qiov_full);
     } else if (fidp->fid_type == P9_FID_XATTR) {
         err = v9fs_xattr_read(s, pdu, fidp, off, max_count);
     } else {
@@ -1966,8 +1962,9 @@ static void v9fs_readdir(void *opaque)
     V9fsFidState *fidp;
     ssize_t retval = 0;
     size_t offset = 7;
-    int64_t initial_offset;
-    int32_t count, max_count;
+    uint64_t initial_offset;
+    int32_t count;
+    uint32_t max_count;
     V9fsPDU *pdu = opaque;
     V9fsState *s = pdu->s;
 
@@ -2005,7 +2002,7 @@ out_nofid:
 }
 
 static int v9fs_xattr_write(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp,
-                            int64_t off, int32_t count,
+                            uint64_t off, uint32_t count,
                             struct iovec *sg, int cnt)
 {
     int i, to_copy;
@@ -2050,22 +2047,22 @@ out:
 
 static void v9fs_write(void *opaque)
 {
-    int cnt;
     ssize_t err;
     int32_t fid;
-    int64_t off;
-    int32_t count;
+    uint64_t off;
+    uint32_t count;
     int32_t len = 0;
     int32_t total = 0;
     size_t offset = 7;
     V9fsFidState *fidp;
-    struct iovec iov[128]; /* FIXME: bad, bad, bad */
-    struct iovec *sg = iov;
     V9fsPDU *pdu = opaque;
     V9fsState *s = pdu->s;
+    QEMUIOVector qiov_full;
+    QEMUIOVector qiov;
 
-    pdu_unmarshal(pdu, offset, "dqdv", &fid, &off, &count, sg, &cnt);
-    trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, cnt);
+    offset += pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &count);
+    v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset, count, true);
+    trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, qiov_full.niov);
 
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {
@@ -2081,20 +2078,23 @@ static void v9fs_write(void *opaque)
         /*
          * setxattr operation
          */
-        err = v9fs_xattr_write(s, pdu, fidp, off, count, sg, cnt);
+        err = v9fs_xattr_write(s, pdu, fidp, off, count,
+                               qiov_full.iov, qiov_full.niov);
         goto out;
     } else {
         err = -EINVAL;
         goto out;
     }
-    sg = cap_sg(sg, count, &cnt);
+    qemu_iovec_init(&qiov, qiov_full.niov);
     do {
+        qemu_iovec_reset(&qiov);
+        qemu_iovec_copy(&qiov, &qiov_full, total, qiov_full.size - total);
         if (0) {
-            print_sg(sg, cnt);
+            print_sg(qiov.iov, qiov.niov);
         }
         /* Loop in case of EINTR */
         do {
-            len = v9fs_co_pwritev(pdu, fidp, sg, cnt, off);
+            len = v9fs_co_pwritev(pdu, fidp, qiov.iov, qiov.niov, off);
             if (len >= 0) {
                 off   += len;
                 total += len;
@@ -2103,16 +2103,20 @@ static void v9fs_write(void *opaque)
         if (len < 0) {
             /* IO error return the error */
             err = len;
-            goto out;
+            goto out_qiov;
         }
-        sg = adjust_sg(sg, len, &cnt);
     } while (total < count && len > 0);
+
+    offset = 7;
     offset += pdu_marshal(pdu, offset, "d", total);
     err = offset;
     trace_v9fs_write_return(pdu->tag, pdu->id, total, err);
+out_qiov:
+    qemu_iovec_destroy(&qiov);
 out:
     put_fid(pdu, fidp);
 out_nofid:
+    qemu_iovec_destroy(&qiov_full);
     complete_pdu(s, pdu, err);
 }