9pfs: local: improve error handling in link op

When using the mapped-file security model, we also have to create a link
for the metadata file if it exists. In case of failure, we should rollback.

That's what this patch does.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Greg Kurz 2017-02-26 23:44:11 +01:00
parent d2767edec5
commit 6dd4b1f1d0

View File

@ -920,6 +920,7 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
int ret;
V9fsString newpath;
char *buffer, *buffer1;
int serrno;
v9fs_string_init(&newpath);
v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
@ -928,25 +929,36 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
buffer1 = rpath(ctx, newpath.data);
ret = link(buffer, buffer1);
g_free(buffer);
g_free(buffer1);
if (ret < 0) {
goto out;
}
/* now link the virtfs_metadata files */
if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
char *vbuffer, *vbuffer1;
/* Link the .virtfs_metadata files. Create the metada directory */
ret = local_create_mapped_attr_dir(ctx, newpath.data);
if (ret < 0) {
goto err_out;
}
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);
vbuffer = local_mapped_attr_path(ctx, oldpath->data);
vbuffer1 = local_mapped_attr_path(ctx, newpath.data);
ret = link(vbuffer, vbuffer1);
g_free(vbuffer);
g_free(vbuffer1);
if (ret < 0 && errno != ENOENT) {
goto err_out;
}
}
goto out;
err_out:
serrno = errno;
remove(buffer1);
errno = serrno;
out:
g_free(buffer1);
v9fs_string_free(&newpath);
return ret;
}
@ -1189,14 +1201,12 @@ static int local_renameat(FsContext *ctx, V9fsPath *olddir,
goto err_undo_rename;
}
omap_dirfd = openat(odirfd, VIRTFS_META_DIR,
O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
if (omap_dirfd == -1) {
goto err;
}
nmap_dirfd = openat(ndirfd, VIRTFS_META_DIR,
O_RDONLY | O_DIRECTORY | O_NOFOLLOW);
nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
if (nmap_dirfd == -1) {
close_preserve_errno(omap_dirfd);
goto err;