VirtFS update

From: Chen Gang <[email protected]>

When path is truncated by PATH_MAX limitation, it causes QEMU to access incorrect file. So use original full path instead of PATH_MAX within 9pfs (need check/process ENOMEM for related memory allocation).

The related test:

- Environments (for qemu-devel):

   - Host is under fedora17 desktop with ext4fs:

     qemu-system-x86_64 -hda test.img -m 1024 \
       -net nic,vlan=4,model=virtio,macaddr=00:16:35:AF:94:04 \
       -net tap,vlan=4,ifname=tap4,script=no,downscript=no \
       -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=hostshare \
       -fsdev local,security_model=passthrough,id=fsdev0,\
         path=/upstream/vm/data/share/1234567890abcdefghijklmnopqrstuvwxyz\
           ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmnopqrstuvwxyz\
           ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111111111\
           1111111111111111111111111111111111111111111111111111222222222222\
           2222222222222222222222222222222222222222222222222222222222222222\
           2222222222222222222222222222222222233333333333333333333333333333\
           3333333333333333333333333333333333

    - Guest is ubuntu12 server with 9pfs.

      mount -t 9p -o trans=virtio,version=9p2000.L hostshare /share

    - Limitations:

      full path limitation is PATH_MAX (4096B include nul) under Linux.
      file/dir node name maximized length is 256 (include nul) under ext4.

- Special test:

    Under host, modify the file: "/upstream/vm/data/share/1234567890abcdefg\
      hijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmno\
      pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111\
      111111111111111111111111111111111111111111111111111111111122222222222\
      222222222222222222222222222222222222222222222222222222222222222222222\
      222222222222222222222222222222233333333333333333333333333333333333333\
      3333333333333333333333333/4444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444/55555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      55555555/666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666/77777777777777777777777777777777777777777777777\
      777777777777777777777777777777777777777777777777777777777777777777777\
      777777777777777777777777777777777777777777777777777777777777777777777\
      77777777777777777777777777777777777777777777777777777777777/888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888/99999999999999999999999999999999999999999999999999999999999\
      999999999999999999999999999999999999999999999999999999999999999999999\
      999999999999999999999999999999999999999999999999999999999999999999999\
      99999999999999999999999999999999999999999/000000000000000000000000000\
      000000000000000000000000000000000000000000000000000000000000000000000\
      000000000000000000000000000000000000000000000000000000000000000000000\
      000000000000000000000000000000000000000000000000/aaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/ccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      cccccccccc/dddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      dddddddddddddddddddddd/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee/fffffffffffffff\
      fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
      fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
      ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff/gggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggg/iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii/jjjjjjjjjjjjj\
      jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj\
      jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj/ppppppppppppppppppppp\
      ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp\
      ppppppppppppppppppppppppppppppppppppppp/test1234567890file.log"
        (need enter dir firstly, then modify file, or can not open it).

Under guest, still allow modify "test1234567890file.log" (will generate "test123456" file with contents).

After apply this patch, can not open "test1234567890file.log" under guest (permission denied).

- Common test:

All are still OK after apply this path.

"mkdir -p", "create/open file/dir", "modify file/dir", "rm file/dir". change various mount point paths under host and/or guest.

Signed-off-by Chen Gang <[email protected]>

Signed-off-by Aneesh Kumar K.V <[email protected]>

---
 hw/9pfs/cofs.c                 |  48 +++++--
 hw/9pfs/virtio-9p-handle.c     |   9 +-
 hw/9pfs/virtio-9p-local.c      | 287 +++++++++++++++++++++++++++--------------
 hw/9pfs/virtio-9p-posix-acl.c  |  52 ++++++--
 hw/9pfs/virtio-9p-xattr-user.c |  27 +++-
 hw/9pfs/virtio-9p-xattr.c      |   9 +-
 hw/9pfs/virtio-9p-xattr.h      |  27 +++-
 hw/9pfs/virtio-9p.h            |   6 +-
 8 files changed, 316 insertions(+), 149 deletions(-)

hw/9pfs/cofs.c +34 -14

index 389105074852..0aba70ad792f 100644
@@ -17,35 +17,55 @@
 #include "block/coroutine.h"
 #include "virtio-9p-coth.h"
 
+static ssize_t __readlink(V9fsState *s, V9fsPath *path, V9fsString *buf)
+{
+    ssize_t len, maxlen = PATH_MAX;
+
+    buf->data = g_malloc(PATH_MAX);
+    for (;;) {
+        len = s->ops->readlink(&s->ctx, path, buf->data, maxlen);
+        if (len < 0) {
+            g_free(buf->data);
+            buf->data = NULL;
+            buf->size = 0;
+            break;
+        } else if (len == maxlen) {
+            /*
+             * We dodn't have space to put the NULL or we have more
+             * to read. Increase the size and try again
+             */
+            maxlen *= 2;
+            g_free(buf->data);
+            buf->data = g_malloc(maxlen);
+            continue;
+        }
+        /*
+         * Null terminate the readlink output
+         */
+        buf->data[len] = '\0';
+        buf->size = len;
+        break;
+    }
+    return len;
+}
+
 int v9fs_co_readlink(V9fsPDU *pdu, V9fsPath *path, V9fsString *buf)
 {
     int err;
-    ssize_t len;
     V9fsState *s = pdu->s;
 
     if (v9fs_request_cancelled(pdu)) {
         return -EINTR;
     }
-    buf->data = g_malloc(PATH_MAX);
     v9fs_path_read_lock(s);
     v9fs_co_run_in_worker(
         {
-            len = s->ops->readlink(&s->ctx, path,
-                                   buf->data, PATH_MAX - 1);
-            if (len > -1) {
-                buf->size = len;
-                buf->data[len] = 0;
-                err = 0;
-            } else {
+            err = __readlink(s, path, buf);
+            if (err < 0) {
                 err = -errno;
             }
         });
     v9fs_path_unlock(s);
-    if (err) {
-        g_free(buf->data);
-        buf->data = NULL;
-        buf->size = 0;
-    }
     return err;
 }
 

hw/9pfs/virtio-9p-handle.c +6 -3

index 17002a3d2867..4b79cefd135e 100644
@@ -498,7 +498,7 @@ static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
                               const char *name, V9fsPath *target)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
     struct file_handle *fh;
     int dirfd, ret, mnt_id;
     struct handle_data *data = (struct handle_data *)ctx->private;

@@ -513,7 +513,9 @@ static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
         dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
     } else {
         /* relative to export root */
-        dirfd = open(rpath(ctx, ".", buffer), O_DIRECTORY);
+        buffer = rpath(ctx, ".");
+        dirfd = open(buffer, O_DIRECTORY);
+        g_free(buffer);
     }
     if (dirfd < 0) {
         return dirfd;

@@ -521,7 +523,7 @@ static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
     fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
     fh->handle_bytes = data->handle_bytes;
     /* add a "./" at the beginning of the path */
-    snprintf(buffer, PATH_MAX, "./%s", name);
+    buffer = g_strdup_printf("./%s", name);
     /* flag = 0 imply don't follow symlink */
     ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
     if (!ret) {

@@ -531,6 +533,7 @@ static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
         g_free(fh);
     }
     close(dirfd);
+    g_free(buffer);
     return ret;
 }
 

hw/9pfs/virtio-9p-local.c +187 -100

index dc615a4d0fa4..56b302c122b6 100644
@@ -42,18 +42,18 @@
 
 #define VIRTFS_META_DIR ".virtfs_metadata"
 
-static const char *local_mapped_attr_path(FsContext *ctx,
-                                          const char *path, char *buffer)
+static char *local_mapped_attr_path(FsContext *ctx, const char *path)
 {
     char *dir_name;
     char *tmp_path = g_strdup(path);
     char *base_name = basename(tmp_path);
+    char *buffer;
 
     /* NULL terminate the directory */
     dir_name = tmp_path;
     *(base_name - 1) = '\0';
 
-    snprintf(buffer, PATH_MAX, "%s/%s/%s/%s",
+    buffer = g_strdup_printf("%s/%s/%s/%s",
              ctx->fs_root, dir_name, VIRTFS_META_DIR, base_name);
     g_free(tmp_path);
     return buffer;

@@ -92,10 +92,11 @@ static void local_mapped_file_attr(FsContext *ctx, const char *path,
 {
     FILE *fp;
     char buf[ATTR_MAX];
-    char attr_path[PATH_MAX];
+    char *attr_path;
 
-    local_mapped_attr_path(ctx, path, attr_path);
+    attr_path = local_mapped_attr_path(ctx, path);
     fp = local_fopen(attr_path, "r");
+    g_free(attr_path);
     if (!fp) {
         return;
     }

@@ -118,12 +119,13 @@ static void local_mapped_file_attr(FsContext *ctx, const char *path,
 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
     int err;
-    char buffer[PATH_MAX];
+    char *buffer;
     char *path = fs_path->data;
 
-    err =  lstat(rpath(fs_ctx, path, buffer), stbuf);
+    buffer = rpath(fs_ctx, path);
+    err =  lstat(buffer, stbuf);
     if (err) {
-        return err;
+        goto err_out;
     }
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         /* Actual credentials are part of extended attrs */

@@ -131,41 +133,42 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
         gid_t tmp_gid;
         mode_t tmp_mode;
         dev_t tmp_dev;
-        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.uid", &tmp_uid,
-                    sizeof(uid_t)) > 0) {
+        if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
             stbuf->st_uid = tmp_uid;
         }
-        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.gid", &tmp_gid,
-                    sizeof(gid_t)) > 0) {
+        if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
             stbuf->st_gid = tmp_gid;
         }
-        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.mode",
+        if (getxattr(buffer, "user.virtfs.mode",
                     &tmp_mode, sizeof(mode_t)) > 0) {
             stbuf->st_mode = tmp_mode;
         }
-        if (getxattr(rpath(fs_ctx, path, buffer), "user.virtfs.rdev", &tmp_dev,
-                        sizeof(dev_t)) > 0) {
+        if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
                 stbuf->st_rdev = tmp_dev;
         }
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
         local_mapped_file_attr(fs_ctx, path, stbuf);
     }
+
+err_out:
+    g_free(buffer);
     return err;
 }
 
 static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
 {
     int err;
-    char attr_dir[PATH_MAX];
+    char *attr_dir;
     char *tmp_path = g_strdup(path);
 
-    snprintf(attr_dir, PATH_MAX, "%s/%s/%s",
+    attr_dir = g_strdup_printf("%s/%s/%s",
              ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
 
     err = mkdir(attr_dir, 0700);
     if (err < 0 && errno == EEXIST) {
         err = 0;
     }
+    g_free(attr_dir);
     g_free(tmp_path);
     return err;
 }

@@ -176,10 +179,11 @@ static int local_set_mapped_file_attr(FsContext *ctx,
     FILE *fp;
     int ret = 0;
     char buf[ATTR_MAX];
-    char attr_path[PATH_MAX];
+    char *attr_path;
     int uid = -1, gid = -1, mode = -1, rdev = -1;
 
-    fp = local_fopen(local_mapped_attr_path(ctx, path, attr_path), "r");
+    attr_path = local_mapped_attr_path(ctx, path);
+    fp = local_fopen(attr_path, "r");
     if (!fp) {
         goto create_map_file;
     }

@@ -241,6 +245,7 @@ update_map_file:
     fclose(fp);
 
 err_out:
+    g_free(attr_path);
     return ret;
 }
 

@@ -282,36 +287,43 @@ static int local_set_xattr(const char *path, FsCred *credp)
 static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
                                          FsCred *credp)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
 
-    if (lchown(rpath(fs_ctx, path, buffer), credp->fc_uid,
-                credp->fc_gid) < 0) {
+    buffer = rpath(fs_ctx, path);
+    if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) {
         /*
          * If we fail to change ownership and if we are
          * using security model none. Ignore the error
          */
         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
-            return -1;
+            goto err;
         }
     }
 
-    if (chmod(rpath(fs_ctx, path, buffer), credp->fc_mode & 07777) < 0) {
-        return -1;
+    if (chmod(buffer, credp->fc_mode & 07777) < 0) {
+        goto err;
     }
+
+    g_free(buffer);
     return 0;
+err:
+    g_free(buffer);
+    return -1;
 }
 
 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
                               char *buf, size_t bufsz)
 {
     ssize_t tsize = -1;
-    char buffer[PATH_MAX];
+    char *buffer;
     char *path = fs_path->data;
 
     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
         int fd;
-        fd = open(rpath(fs_ctx, path, buffer), O_RDONLY | O_NOFOLLOW);
+        buffer = rpath(fs_ctx, path);
+        fd = open(buffer, O_RDONLY | O_NOFOLLOW);
+        g_free(buffer);
         if (fd == -1) {
             return -1;
         }

@@ -322,7 +334,9 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
         return tsize;
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        tsize = readlink(rpath(fs_ctx, path, buffer), buf, bufsz);
+        buffer = rpath(fs_ctx, path);
+        tsize = readlink(buffer, buf, bufsz);
+        g_free(buffer);
     }
     return tsize;
 }

@@ -340,20 +354,24 @@ static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 static int local_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
     char *path = fs_path->data;
 
-    fs->fd = open(rpath(ctx, path, buffer), flags | O_NOFOLLOW);
+    buffer = rpath(ctx, path);
+    fs->fd = open(buffer, flags | O_NOFOLLOW);
+    g_free(buffer);
     return fs->fd;
 }
 
 static int local_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
     char *path = fs_path->data;
 
-    fs->dir = opendir(rpath(ctx, path, buffer));
+    buffer = rpath(ctx, path);
+    fs->dir = opendir(buffer);
+    g_free(buffer);
     if (!fs->dir) {
         return -1;
     }

@@ -441,18 +459,23 @@ static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 
 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret = -1;
     char *path = fs_path->data;
 
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+        buffer = rpath(fs_ctx, path);
+        ret = local_set_xattr(buffer, credp);
+        g_free(buffer);
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
         return local_set_mapped_file_attr(fs_ctx, path, credp);
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        return chmod(rpath(fs_ctx, path, buffer), credp->fc_mode);
+        buffer = rpath(fs_ctx, path);
+        ret = chmod(buffer, credp->fc_mode);
+        g_free(buffer);
     }
-    return -1;
+    return ret;
 }
 
 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,

@@ -462,7 +485,7 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);

@@ -470,21 +493,23 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 
     /* Determine the security model */
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        err = mknod(rpath(fs_ctx, path, buffer),
-                SM_LOCAL_MODE_BITS|S_IFREG, 0);
+        buffer = rpath(fs_ctx, path);
+        err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
-        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+        err = local_set_xattr(buffer, credp);
         if (err == -1) {
             serrno = errno;
             goto err_end;
         }
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 
-        err = mknod(rpath(fs_ctx, path, buffer),
-                    SM_LOCAL_MODE_BITS|S_IFREG, 0);
+        buffer = rpath(fs_ctx, path);
+        err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
         err = local_set_mapped_file_attr(fs_ctx, path, credp);

@@ -494,9 +519,10 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        err = mknod(rpath(fs_ctx, path, buffer), credp->fc_mode,
-                credp->fc_rdev);
+        buffer = rpath(fs_ctx, path);
+        err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
         err = local_post_create_passthrough(fs_ctx, path, credp);

@@ -508,8 +534,9 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     goto out;
 
 err_end:
-    remove(rpath(fs_ctx, path, buffer));
+    remove(buffer);
     errno = serrno;
+    g_free(buffer);
 out:
     v9fs_string_free(&fullname);
     return err;

@@ -522,7 +549,7 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);

@@ -530,19 +557,23 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 
     /* Determine the security model */
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
+        buffer = rpath(fs_ctx, path);
+        err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFDIR;
-        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+        err = local_set_xattr(buffer, credp);
         if (err == -1) {
             serrno = errno;
             goto err_end;
         }
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        err = mkdir(rpath(fs_ctx, path, buffer), SM_LOCAL_DIR_MODE_BITS);
+        buffer = rpath(fs_ctx, path);
+        err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFDIR;

@@ -553,8 +584,10 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        err = mkdir(rpath(fs_ctx, path, buffer), credp->fc_mode);
+        buffer = rpath(fs_ctx, path);
+        err = mkdir(buffer, credp->fc_mode);
         if (err == -1) {
+            g_free(buffer);
             goto out;
         }
         err = local_post_create_passthrough(fs_ctx, path, credp);

@@ -566,8 +599,9 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     goto out;
 
 err_end:
-    remove(rpath(fs_ctx, path, buffer));
+    remove(buffer);
     errno = serrno;
+    g_free(buffer);
 out:
     v9fs_string_free(&fullname);
     return err;

@@ -626,7 +660,7 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     /*
      * Mark all the open to not follow symlinks

@@ -639,21 +673,25 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 
     /* Determine the security model */
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
+        buffer = rpath(fs_ctx, path);
+        fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
+            g_free(buffer);
             err = fd;
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFREG;
         /* Set cleint credentials in xattr */
-        err = local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+        err = local_set_xattr(buffer, credp);
         if (err == -1) {
             serrno = errno;
             goto err_end;
         }
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        fd = open(rpath(fs_ctx, path, buffer), flags, SM_LOCAL_MODE_BITS);
+        buffer = rpath(fs_ctx, path);
+        fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
+            g_free(buffer);
             err = fd;
             goto out;
         }

@@ -666,8 +704,10 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        fd = open(rpath(fs_ctx, path, buffer), flags, credp->fc_mode);
+        buffer = rpath(fs_ctx, path);
+        fd = open(buffer, flags, credp->fc_mode);
         if (fd == -1) {
+            g_free(buffer);
             err = fd;
             goto out;
         }

@@ -683,8 +723,9 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 
 err_end:
     close(fd);
-    remove(rpath(fs_ctx, path, buffer));
+    remove(buffer);
     errno = serrno;
+    g_free(buffer);
 out:
     v9fs_string_free(&fullname);
     return err;

@@ -698,7 +739,7 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     int serrno = 0;
     char *newpath;
     V9fsString fullname;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);

@@ -708,10 +749,10 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
         int fd;
         ssize_t oldpath_size, write_size;
-        fd = open(rpath(fs_ctx, newpath, buffer),
-                  O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW,
-                  SM_LOCAL_MODE_BITS);
+        buffer = rpath(fs_ctx, newpath);
+        fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
+            g_free(buffer);
             err = fd;
             goto out;
         }

@@ -730,7 +771,7 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         close(fd);
         /* Set cleint credentials in symlink's xattr */
         credp->fc_mode = credp->fc_mode|S_IFLNK;
-        err = local_set_xattr(rpath(fs_ctx, newpath, buffer), credp);
+        err = local_set_xattr(buffer, credp);
         if (err == -1) {
             serrno = errno;
             goto err_end;

@@ -738,10 +779,10 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
         int fd;
         ssize_t oldpath_size, write_size;
-        fd = open(rpath(fs_ctx, newpath, buffer),
-                  O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW,
-                  SM_LOCAL_MODE_BITS);
+        buffer = rpath(fs_ctx, newpath);
+        fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
+            g_free(buffer);
             err = fd;
             goto out;
         }

@@ -767,12 +808,13 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         }
     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
                (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        err = symlink(oldpath, rpath(fs_ctx, newpath, buffer));
+        buffer = rpath(fs_ctx, newpath);
+        err = symlink(oldpath, buffer);
         if (err) {
+            g_free(buffer);
             goto out;
         }
-        err = lchown(rpath(fs_ctx, newpath, buffer), credp->fc_uid,
-                     credp->fc_gid);
+        err = lchown(buffer, credp->fc_uid, credp->fc_gid);
         if (err == -1) {
             /*
              * If we fail to change ownership and if we are

@@ -788,8 +830,9 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     goto out;
 
 err_end:
-    remove(rpath(fs_ctx, newpath, buffer));
+    remove(buffer);
     errno = serrno;
+    g_free(buffer);
 out:
     v9fs_string_free(&fullname);
     return err;

@@ -800,13 +843,16 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
 {
     int ret;
     V9fsString newpath;
-    char buffer[PATH_MAX], buffer1[PATH_MAX];
+    char *buffer, *buffer1;
 
     v9fs_string_init(&newpath);
     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 
-    ret = link(rpath(ctx, oldpath->data, buffer),
-               rpath(ctx, newpath.data, buffer1));
+    buffer = rpath(ctx, oldpath->data);
+    buffer1 = rpath(ctx, newpath.data);
+    ret = link(buffer, buffer1);
+    g_free(buffer);
+    g_free(buffer1);
 
     /* now link the virtfs_metadata files */
     if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {

@@ -815,8 +861,11 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
         if (ret < 0) {
             goto err_out;
         }
-        ret = link(local_mapped_attr_path(ctx, oldpath->data, buffer),
-                   local_mapped_attr_path(ctx, newpath.data, buffer1));
+        buffer = local_mapped_attr_path(ctx, oldpath->data);
+        buffer1 = local_mapped_attr_path(ctx, newpath.data);
+        ret = link(buffer, buffer1);
+        g_free(buffer);
+        g_free(buffer1);
         if (ret < 0 && errno != ENOENT) {
             goto err_out;
         }

@@ -828,17 +877,21 @@ err_out:
 
 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret;
     char *path = fs_path->data;
 
-    return truncate(rpath(ctx, path, buffer), size);
+    buffer = rpath(ctx, path);
+    ret = truncate(buffer, size);
+    g_free(buffer);
+    return ret;
 }
 
 static int local_rename(FsContext *ctx, const char *oldpath,
                         const char *newpath)
 {
     int err;
-    char buffer[PATH_MAX], buffer1[PATH_MAX];
+    char *buffer, *buffer1;
 
     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
         err = local_create_mapped_attr_dir(ctx, newpath);

@@ -846,50 +899,69 @@ static int local_rename(FsContext *ctx, const char *oldpath,
             return err;
         }
         /* rename the .virtfs_metadata files */
-        err = rename(local_mapped_attr_path(ctx, oldpath, buffer),
-                     local_mapped_attr_path(ctx, newpath, buffer1));
+        buffer = local_mapped_attr_path(ctx, oldpath);
+        buffer1 = local_mapped_attr_path(ctx, newpath);
+        err = rename(buffer, buffer1);
+        g_free(buffer);
+        g_free(buffer1);
         if (err < 0 && errno != ENOENT) {
             return err;
         }
     }
-    return rename(rpath(ctx, oldpath, buffer), rpath(ctx, newpath, buffer1));
+
+    buffer = rpath(ctx, oldpath);
+    buffer1 = rpath(ctx, newpath);
+    err = rename(buffer, buffer1);
+    g_free(buffer);
+    g_free(buffer1);
+    return err;
 }
 
 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret = -1;
     char *path = fs_path->data;
 
     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
         (fs_ctx->export_flags & V9FS_SM_NONE)) {
-        return lchown(rpath(fs_ctx, path, buffer),
-                      credp->fc_uid, credp->fc_gid);
+        buffer = rpath(fs_ctx, path);
+        ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
+        g_free(buffer);
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
-        return local_set_xattr(rpath(fs_ctx, path, buffer), credp);
+        buffer = rpath(fs_ctx, path);
+        ret = local_set_xattr(buffer, credp);
+        g_free(buffer);
     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
         return local_set_mapped_file_attr(fs_ctx, path, credp);
     }
-    return -1;
+    return ret;
 }
 
 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
                            const struct timespec *buf)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret;
     char *path = fs_path->data;
 
-    return qemu_utimens(rpath(s, path, buffer), buf);
+    buffer = rpath(s, path);
+    ret = qemu_utimens(buffer, buf);
+    g_free(buffer);
+    return ret;
 }
 
 static int local_remove(FsContext *ctx, const char *path)
 {
     int err;
     struct stat stbuf;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
-        err =  lstat(rpath(ctx, path, buffer), &stbuf);
+        buffer = rpath(ctx, path);
+        err =  lstat(buffer, &stbuf);
+        g_free(buffer);
         if (err) {
             goto err_out;
         }

@@ -898,9 +970,10 @@ static int local_remove(FsContext *ctx, const char *path)
          * directory
          */
         if (S_ISDIR(stbuf.st_mode)) {
-            snprintf(buffer, ARRAY_SIZE(buffer), "%s/%s/%s",
-                     ctx->fs_root, path, VIRTFS_META_DIR);
+            buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
+                                     path, VIRTFS_META_DIR);
             err = remove(buffer);
+            g_free(buffer);
             if (err < 0 && errno != ENOENT) {
                 /*
                  * We didn't had the .virtfs_metadata file. May be file created

@@ -913,7 +986,9 @@ static int local_remove(FsContext *ctx, const char *path)
          * Now remove the name from parent directory
          * .virtfs_metadata directory
          */
-        err = remove(local_mapped_attr_path(ctx, path, buffer));
+        buffer = local_mapped_attr_path(ctx, path);
+        err = remove(buffer);
+        g_free(buffer);
         if (err < 0 && errno != ENOENT) {
             /*
              * We didn't had the .virtfs_metadata file. May be file created

@@ -922,7 +997,10 @@ static int local_remove(FsContext *ctx, const char *path)
             goto err_out;
         }
     }
-    return remove(rpath(ctx, path, buffer));
+
+    buffer = rpath(ctx, path);
+    err = remove(buffer);
+    g_free(buffer);
 err_out:
     return err;
 }

@@ -947,10 +1025,14 @@ static int local_fsync(FsContext *ctx, int fid_type,
 
 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret;
     char *path = fs_path->data;
 
-    return statfs(rpath(s, path, buffer), stbuf);
+    buffer = rpath(s, path);
+    ret = statfs(buffer, stbuf);
+    g_free(buffer);
+    return ret;
 }
 
 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,

@@ -1023,7 +1105,7 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
 {
     int ret;
     V9fsString fullname;
-    char buffer[PATH_MAX];
+    char *buffer;
 
     v9fs_string_init(&fullname);
 

@@ -1034,9 +1116,10 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
              * If directory remove .virtfs_metadata contained in the
              * directory
              */
-            snprintf(buffer, ARRAY_SIZE(buffer), "%s/%s/%s", ctx->fs_root,
-                     fullname.data, VIRTFS_META_DIR);
+            buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
+                                     fullname.data, VIRTFS_META_DIR);
             ret = remove(buffer);
+            g_free(buffer);
             if (ret < 0 && errno != ENOENT) {
                 /*
                  * We didn't had the .virtfs_metadata file. May be file created

@@ -1049,7 +1132,9 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
          * Now remove the name from parent directory
          * .virtfs_metadata directory.
          */
-        ret = remove(local_mapped_attr_path(ctx, fullname.data, buffer));
+        buffer = local_mapped_attr_path(ctx, fullname.data);
+        ret = remove(buffer);
+        g_free(buffer);
         if (ret < 0 && errno != ENOENT) {
             /*
              * We didn't had the .virtfs_metadata file. May be file created

@@ -1059,7 +1144,9 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
         }
     }
     /* Remove the name finally */
-    ret = remove(rpath(ctx, fullname.data, buffer));
+    buffer = rpath(ctx, fullname.data);
+    ret = remove(buffer);
+    g_free(buffer);
 
 err_out:
     v9fs_string_free(&fullname);

hw/9pfs/virtio-9p-posix-acl.c +38 -14

index 339c5ecae441..803d9d94f3b8 100644
@@ -26,8 +26,13 @@
 static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path,
                                 const char *name, void *value, size_t size)
 {
-    char buffer[PATH_MAX];
-    return lgetxattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS, value, size);
+    char *buffer;
+    ssize_t ret;
+
+    buffer = rpath(ctx, path);
+    ret = lgetxattr(buffer, MAP_ACL_ACCESS, value, size);
+    g_free(buffer);
+    return ret;
 }
 
 static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,

@@ -52,17 +57,23 @@ static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
                             void *value, size_t size, int flags)
 {
-    char buffer[PATH_MAX];
-    return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS, value,
-            size, flags);
+    char *buffer;
+    int ret;
+
+    buffer = rpath(ctx, path);
+    ret = lsetxattr(buffer, MAP_ACL_ACCESS, value, size, flags);
+    g_free(buffer);
+    return ret;
 }
 
 static int mp_pacl_removexattr(FsContext *ctx,
                                const char *path, const char *name)
 {
     int ret;
-    char buffer[PATH_MAX];
-    ret  = lremovexattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS);
+    char *buffer;
+
+    buffer = rpath(ctx, path);
+    ret  = lremovexattr(buffer, MAP_ACL_ACCESS);
     if (ret == -1 && errno == ENODATA) {
         /*
          * We don't get ENODATA error when trying to remove a

@@ -72,14 +83,20 @@ static int mp_pacl_removexattr(FsContext *ctx,
         errno = 0;
         ret = 0;
     }
+    g_free(buffer);
     return ret;
 }
 
 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
                                 const char *name, void *value, size_t size)
 {
-    char buffer[PATH_MAX];
-    return lgetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value, size);
+    char *buffer;
+    ssize_t ret;
+
+    buffer = rpath(ctx, path);
+    ret = lgetxattr(buffer, MAP_ACL_DEFAULT, value, size);
+    g_free(buffer);
+    return ret;
 }
 
 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,

@@ -104,17 +121,23 @@ static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
                             void *value, size_t size, int flags)
 {
-    char buffer[PATH_MAX];
-    return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value,
-            size, flags);
+    char *buffer;
+    int ret;
+
+    buffer = rpath(ctx, path);
+    ret = lsetxattr(buffer, MAP_ACL_DEFAULT, value, size, flags);
+    g_free(buffer);
+    return ret;
 }
 
 static int mp_dacl_removexattr(FsContext *ctx,
                                const char *path, const char *name)
 {
     int ret;
-    char buffer[PATH_MAX];
-    ret  = lremovexattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT);
+    char *buffer;
+
+    buffer = rpath(ctx, path);
+    ret  = lremovexattr(buffer, MAP_ACL_DEFAULT);
     if (ret == -1 && errno == ENODATA) {
         /*
          * We don't get ENODATA error when trying to remove a

@@ -124,6 +147,7 @@ static int mp_dacl_removexattr(FsContext *ctx,
         errno = 0;
         ret = 0;
     }
+    g_free(buffer);
     return ret;
 }
 

hw/9pfs/virtio-9p-xattr-user.c +21 -6

index e0c92ebf9e5d..46133e06dbdf 100644
@@ -21,7 +21,9 @@
 static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
                                 const char *name, void *value, size_t size)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    ssize_t ret;
+
     if (strncmp(name, "user.virtfs.", 12) == 0) {
         /*
          * Don't allow fetch of user.virtfs namesapce

@@ -30,7 +32,10 @@ static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
         errno = ENOATTR;
         return -1;
     }
-    return lgetxattr(rpath(ctx, path, buffer), name, value, size);
+    buffer = rpath(ctx, path);
+    ret = lgetxattr(buffer, name, value, size);
+    g_free(buffer);
+    return ret;
 }
 
 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,

@@ -69,7 +74,9 @@ static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
                             void *value, size_t size, int flags)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret;
+
     if (strncmp(name, "user.virtfs.", 12) == 0) {
         /*
          * Don't allow fetch of user.virtfs namesapce

@@ -78,13 +85,18 @@ static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
         errno = EACCES;
         return -1;
     }
-    return lsetxattr(rpath(ctx, path, buffer), name, value, size, flags);
+    buffer = rpath(ctx, path);
+    ret = lsetxattr(buffer, name, value, size, flags);
+    g_free(buffer);
+    return ret;
 }
 
 static int mp_user_removexattr(FsContext *ctx,
                                const char *path, const char *name)
 {
-    char buffer[PATH_MAX];
+    char *buffer;
+    int ret;
+
     if (strncmp(name, "user.virtfs.", 12) == 0) {
         /*
          * Don't allow fetch of user.virtfs namesapce

@@ -93,7 +105,10 @@ static int mp_user_removexattr(FsContext *ctx,
         errno = EACCES;
         return -1;
     }
-    return lremovexattr(rpath(ctx, path, buffer), name);
+    buffer = rpath(ctx, path);
+    ret = lremovexattr(buffer, name);
+    g_free(buffer);
+    return ret;
 }
 
 XattrOperations mapped_user_xattr = {

hw/9pfs/virtio-9p-xattr.c +6 -3

index 3fae557a84ff..07183887c5ee 100644
@@ -67,21 +67,24 @@ ssize_t v9fs_list_xattr(FsContext *ctx, const char *path,
                         void *value, size_t vsize)
 {
     ssize_t size = 0;
-    char buffer[PATH_MAX];
+    char *buffer;
     void *ovalue = value;
     XattrOperations *xops;
     char *orig_value, *orig_value_start;
     ssize_t xattr_len, parsed_len = 0, attr_len;
 
     /* Get the actual len */
-    xattr_len = llistxattr(rpath(ctx, path, buffer), value, 0);
+    buffer = rpath(ctx, path);
+    xattr_len = llistxattr(buffer, value, 0);
     if (xattr_len <= 0) {
+        g_free(buffer);
         return xattr_len;
     }
 
     /* Now fetch the xattr and find the actual size */
     orig_value = g_malloc(xattr_len);
-    xattr_len = llistxattr(rpath(ctx, path, buffer), orig_value, xattr_len);
+    xattr_len = llistxattr(buffer, orig_value, xattr_len);
+    g_free(buffer);
 
     /* store the orig pointer */
     orig_value_start = orig_value;

hw/9pfs/virtio-9p-xattr.h +21 -6

index 41cc6cbc7ba0..327b32b5aa9e 100644
@@ -54,23 +54,38 @@ ssize_t pt_listxattr(FsContext *ctx, const char *path, char *name, void *value,
 static inline ssize_t pt_getxattr(FsContext *ctx, const char *path,
                                   const char *name, void *value, size_t size)
 {
-    char buffer[PATH_MAX];
-    return lgetxattr(rpath(ctx, path, buffer), name, value, size);
+    char *buffer;
+    ssize_t ret;
+
+    buffer = rpath(ctx, path);
+    ret = lgetxattr(buffer, name, value, size);
+    g_free(buffer);
+    return ret;
 }
 
 static inline int pt_setxattr(FsContext *ctx, const char *path,
                               const char *name, void *value,
                               size_t size, int flags)
 {
-    char buffer[PATH_MAX];
-    return lsetxattr(rpath(ctx, path, buffer), name, value, size, flags);
+    char *buffer;
+    int ret;
+
+    buffer = rpath(ctx, path);
+    ret = lsetxattr(buffer, name, value, size, flags);
+    g_free(buffer);
+    return ret;
 }
 
 static inline int pt_removexattr(FsContext *ctx,
                                  const char *path, const char *name)
 {
-    char buffer[PATH_MAX];
-    return lremovexattr(rpath(ctx, path, buffer), name);
+    char *buffer;
+    int ret;
+
+    buffer = rpath(ctx, path);
+    ret = lremovexattr(path, name);
+    g_free(buffer);
+    return ret;
 }
 
 static inline ssize_t notsup_getxattr(FsContext *ctx, const char *path,

hw/9pfs/virtio-9p.h +3 -3

index 1d6eedb7d8bc..2c3603aed0d0 100644
@@ -6,6 +6,7 @@
 #include <sys/time.h>
 #include <utime.h>
 #include <sys/resource.h>
+#include <glib.h>
 #include "hw/virtio/virtio.h"
 #include "fsdev/file-op-9p.h"
 #include "fsdev/virtio-9p-marshal.h"

@@ -112,10 +113,9 @@ enum p9_proto_version {
 
 #define FID_REFERENCED          0x1
 #define FID_NON_RECLAIMABLE     0x2
-static inline const char *rpath(FsContext *ctx, const char *path, char *buffer)
+static inline char *rpath(FsContext *ctx, const char *path)
 {
-    snprintf(buffer, PATH_MAX, "%s/%s", ctx->fs_root, path);
-    return buffer;
+    return g_strdup_printf("%s/%s", ctx->fs_root, path);
 }
 
 /*

OK, thanks.

Next, I will/should continue to analyse the performance issue for 9pfs when users drop into a long directory path under bash shell.

Although I am not quite sure, hope I can find the root cause within month (2014-03-31).

Welcome any suggestions, discussions, and completions for it.

Thanks.

Clean up useless 'break' statement after 'return' statement.

Signed-off-by Chen Gang <[email protected]>

Quoted 3 lines · Chen Gang

Clean up useless 'break' statement after 'return' statement.

Signed-off-by Chen Gang <[email protected]>

Reviewed-by Peter Maydell <[email protected]>

thanks
-- PMM

Clean up useless 'break' statement after 'return' statement.

Signed-off-by Chen Gang <[email protected]>

---
 target-arm/gdbstub64.c |    2 --
 1 file changed, 2 deletions(-)

target-arm/gdbstub64.c +0 -3

index e8a8295..8f3b8d1 100644
@@ -32,10 +32,8 @@ int aarch64_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
     switch (n) {
     case 31:
         return gdb_get_reg64(mem_buf, env->xregs[31]);
-        break;
     case 32:
         return gdb_get_reg64(mem_buf, env->pc);
-        break;
     case 33:
         return gdb_get_reg32(mem_buf, pstate_read(env));
     }
--

1.7.9.5

Quoted 3 lines · Chen Gang

Quoted 3 lines

Clean up useless 'break' statement after 'return' statement.

Signed-off-by Chen Gang <[email protected]>

Reviewed-by Peter Crosthwaite <[email protected]>

Quoted 5 lines · Chen Gang

OK, thanks.

Next, I will/should continue to analyse the performance issue for 9pfs when users drop into a long directory path under bash shell.

After have a test, I am sure it is not 9pfs issue, either not Qemu's issue, it's Linux kernel vfs or block sub-systems' issue. The related test environments (originally, our 9pfs is upper on ext4):

- for ext4 file system under my Fedora laptop (Qemu does not start).

- for ntfs file system under my Fedora laptop (Qemu does not start).

- for ext4 file system under my Ubuntu in Qemu.

For a very long file name (e.g. > 3K long), all of them are very very slow. (and I also tested the ext2 /boot partition under Ubuntu in Qemu, it is not slow, I guess the reson is its partition size is small).

Next, I will/shall communicate with upstream kernel for it. :-)

Quoted 7 lines

Although I am not quite sure, hope I can find the root cause within month (2014-03-31).

Welcome any suggestions, discussions, and completions for it.

Thanks.

From: "Aneesh Kumar K.V" <[email protected]>

After commit ba1183da9a10b94611cad88c44a5c6df005f9b55 we are including hw/Makefile.objs directly from Makefile.target. Make sure hw/Makefile.objs rules doesn't depend on variable defined in Makefile.objs

Tested-by Serge Hallyn <[email protected]>

Signed-off-by Aneesh Kumar K.V <[email protected]>

Am 07.03.2014 16:16, schrieb Aneesh Kumar K.V:

Quoted 8 lines

From: "Aneesh Kumar K.V" <[email protected]>

After commit ba1183da9a10b94611cad88c44a5c6df005f9b55 we are including hw/Makefile.objs directly from Makefile.target. Make sure hw/Makefile.objs rules doesn't depend on variable defined in Makefile.objs

Tested-by Serge Hallyn <[email protected]>

Signed-off-by Aneesh Kumar K.V <[email protected]>

Missing my Tested-by FWIW - but getting it fixed is the important part.

Hi,

Please pull the below update for VirtFS

The following changes since commit d5001cf787ad0514839a81d0f2e771e01e076e21:

xilinx: Delete hw/include/xilinx.h (2014-02-26 14:54:45 +1000)

are available in the git repository at:

https://github.com/kvaneesh/qemu.git for-upstream

for you to fetch changes up to 993c91a0e996346c7ee8fa2ca310cc76edb59e17:

hw/9pfs: Include virtio-9p-device.o in build (2014-03-04 09:20:49 +0530)