Image metadata updates

[wimlib] / src / mount_image.c

diff --git a/src/mount_image.c b/src/mount_image.c
index bca9e4390e473c7987ae04f0522ccf6ab91901c7..18c3a4ef5c2ca2c865c968773ed3174cd6ceb84a 100644 (file)
--- a/src/mount_image.c
+++ b/src/mount_image.c
@@ -8,7 +8,7 @@
  */
 
 /*
  */
 
 /*

- * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
+ * Copyright (C) 2012-2016 Eric Biggers

  *
  * This file is free software; you can redistribute it and/or modify it under
  * the terms of the GNU Lesser General Public License as published by the Free
  *
  * This file is free software; you can redistribute it and/or modify it under
  * the terms of the GNU Lesser General Public License as published by the Free


@@ -164,9 +164,9 @@ struct wimfs_context {
        /* Number of file descriptors open to the mounted WIM image.  */
        unsigned long num_open_fds;
 
        /* Number of file descriptors open to the mounted WIM image.  */
        unsigned long num_open_fds;
 

-       /* Original list of blobs in the mounted image, linked by
-        * 'struct blob_descriptor'.orig_blob_list.  */
-       struct list_head orig_blob_list;
+       /* For read-write mounts, the original metadata resource of the mounted
+        * image.  */
+       struct blob_descriptor *metadata_resource;

 
        /* Parameters for unmounting the image (can be set via extended
         * attribute "wimfs.unmount_info").  */
 
        /* Parameters for unmounting the image (can be set via extended
         * attribute "wimfs.unmount_info").  */


@@ -964,17 +964,6 @@ prepare_inodes(struct wimfs_context *ctx)
        }
 }
 
        }
 }
 

-static void
-release_extra_refcnts(struct wimfs_context *ctx)
-{
-       struct list_head *list = &ctx->orig_blob_list;
-       struct blob_table *blob_table = ctx->wim->blob_table;
-       struct blob_descriptor *blob, *tmp;
-
-       list_for_each_entry_safe(blob, tmp, list, orig_blob_list)
-               blob_subtract_refcnt(blob, blob_table, blob->out_refcnt);
-}
-

 /* Delete the 'struct blob_descriptor' for any stream that was modified
  * or created in the read-write mounted image and had a final size of 0.  */
 static void
 /* Delete the 'struct blob_descriptor' for any stream that was modified
  * or created in the read-write mounted image and had a final size of 0.  */
 static void


@@ -1030,52 +1019,56 @@ static int
 renew_current_image(struct wimfs_context *ctx)
 {
        WIMStruct *wim = ctx->wim;
 renew_current_image(struct wimfs_context *ctx)
 {
        WIMStruct *wim = ctx->wim;

-       int idx = wim->current_image - 1;
-       struct wim_image_metadata *imd = wim->image_metadata[idx];
-       struct wim_image_metadata *replace_imd;
-       struct blob_descriptor *new_blob;
+       int image = wim->current_image;
+       struct wim_image_metadata *imd;
+       struct wim_inode *inode;

        int ret;
 
        int ret;
 

-       /* Create 'replace_imd' structure to use for the reset original,
-        * unmodified image.  */

        ret = WIMLIB_ERR_NOMEM;
        ret = WIMLIB_ERR_NOMEM;

-       replace_imd = new_image_metadata();
-       if (!replace_imd)
+       imd = new_unloaded_image_metadata(ctx->metadata_resource);
+       if (!imd)

                goto err;
 
                goto err;
 

-       /* Create new blob descriptor for the modified image's metadata
-        * resource, which doesn't exist yet.  */
-       ret = WIMLIB_ERR_NOMEM;
-       new_blob = new_blob_descriptor();
-       if (!new_blob)
-               goto err_put_replace_imd;
-
-       new_blob->refcnt = 1;
-       new_blob->is_metadata = 1;
-
-       /* Make the image being moved available at a new index.  Increments the
-        * WIM's image count, but does not increment the reference count of the
-        * 'struct image_metadata'.  */
-       ret = append_image_metadata(wim, imd);
+       ret = append_image_metadata(wim, wim->image_metadata[image - 1]);

        if (ret)
        if (ret)

-               goto err_free_new_blob;
+               goto err_put_imd;

 
 

-       ret = xml_add_image(wim->xml_info, NULL);
+       ret = xml_export_image(wim->xml_info, image,
+                              wim->xml_info, NULL, NULL, false);

        if (ret)
                goto err_undo_append;
 
        if (ret)
                goto err_undo_append;
 

-       replace_imd->metadata_blob = imd->metadata_blob;
-       imd->metadata_blob = new_blob;
-       wim->image_metadata[idx] = replace_imd;
+       wim->image_metadata[image - 1] = imd;

        wim->current_image = wim->hdr.image_count;
        wim->current_image = wim->hdr.image_count;

+
+       ret = select_wim_image(wim, image);
+       if (ret)
+               goto err_undo_export;
+
+       image_for_each_inode(inode, imd) {
+               for (unsigned i = 0; i < inode->i_num_streams; i++) {
+                       struct blob_descriptor *blob;
+
+                       blob = stream_blob(&inode->i_streams[i],
+                                          wim->blob_table);
+                       if (blob)
+                               blob->refcnt += inode->i_nlink;
+               }
+       }
+
+       select_wim_image(wim, wim->hdr.image_count);
+       ctx->metadata_resource = NULL;

        return 0;
 
        return 0;
 

+err_undo_export:
+       xml_delete_image(wim->xml_info, wim->hdr.image_count);
+       wim->image_metadata[image - 1] = wim->image_metadata[wim->hdr.image_count - 1];
+       wim->current_image = image;

 err_undo_append:
        wim->hdr.image_count--;
 err_undo_append:
        wim->hdr.image_count--;

-err_free_new_blob:
-       free_blob_descriptor(new_blob);
-err_put_replace_imd:
-       put_image_metadata(replace_imd, NULL);
+err_put_imd:
+       imd->metadata_blob = NULL;
+       put_image_metadata(imd);

 err:
        return ret;
 }
 err:
        return ret;
 }


@@ -1111,12 +1104,8 @@ commit_image(struct wimfs_context *ctx, int unmount_flags, mqd_t mq)
                int ret = renew_current_image(ctx);
                if (ret)
                        return ret;
                int ret = renew_current_image(ctx);
                if (ret)
                        return ret;

-       } else {
-               release_extra_refcnts(ctx);

        }
        }

-       INIT_LIST_HEAD(&ctx->orig_blob_list);

        delete_empty_blobs(ctx);
        delete_empty_blobs(ctx);

-       mark_image_dirty(wim_get_current_image_metadata(ctx->wim));

 
        write_flags = 0;
 
 
        write_flags = 0;
 


@@ -2161,49 +2150,23 @@ wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
        ctx.mount_flags = mount_flags;
        if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
                ctx.default_lookup_flags = LOOKUP_FLAG_ADS_OK;
        ctx.mount_flags = mount_flags;
        if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
                ctx.default_lookup_flags = LOOKUP_FLAG_ADS_OK;

-       /* For read-write mount, create the staging directory.  */
+
+       /* For read-write mounts, create the staging directory, save a reference
+        * to the image's metadata resource, and mark the image dirty.  */

        if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
                ret = make_staging_dir(&ctx, staging_dir);
                if (ret)
        if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
                ret = make_staging_dir(&ctx, staging_dir);
                if (ret)

-                       goto out_unlock;
+                       goto out;
+               ret = WIMLIB_ERR_NOMEM;
+               ctx.metadata_resource = clone_blob_descriptor(
+                                                       imd->metadata_blob);
+               if (!ctx.metadata_resource)
+                       goto out;
+               mark_image_dirty(imd);

        }
        ctx.owner_uid = getuid();
        ctx.owner_gid = getgid();
 
        }
        ctx.owner_uid = getuid();
        ctx.owner_gid = getgid();
 

-       /* Add each blob referenced by files in the image to a list and
-        * preemptively double the number of references to each.  This is done
-        * to allow implementing the WIMLIB_UNMOUNT_FLAG_NEW_IMAGE semantics.
-        */
-       INIT_LIST_HEAD(&ctx.orig_blob_list);
-       if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
-               unsigned i;
-               struct wim_inode *inode;
-               struct blob_descriptor *blob;
-
-               image_for_each_inode(inode, imd) {
-                       for (i = 0; i < inode->i_num_streams; i++) {
-                               blob = stream_blob(&inode->i_streams[i],
-                                                  wim->blob_table);
-                               if (blob)
-                                       blob->out_refcnt = 0;
-                       }
-               }
-
-               image_for_each_inode(inode, imd) {
-                       for (i = 0; i < inode->i_num_streams; i++) {
-                               blob = stream_blob(&inode->i_streams[i],
-                                                  wim->blob_table);
-                               if (blob) {
-                                       if (blob->out_refcnt == 0)
-                                               list_add(&blob->orig_blob_list,
-                                                        &ctx.orig_blob_list);
-                                       blob->out_refcnt += inode->i_nlink;
-                                       blob->refcnt += inode->i_nlink;
-                               }
-                       }
-               }
-       }
-

        /* Number the inodes in the mounted image sequentially and initialize
         * the file descriptor arrays  */
        prepare_inodes(&ctx);
        /* Number the inodes in the mounted image sequentially and initialize
         * the file descriptor arrays  */
        prepare_inodes(&ctx);


@@ -2298,11 +2261,11 @@ wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
        /* Cleanup and return.  */
        if (ret)
                ret = WIMLIB_ERR_FUSE;
        /* Cleanup and return.  */
        if (ret)
                ret = WIMLIB_ERR_FUSE;

+out:

        FREE(ctx.mountpoint_abspath);
        FREE(ctx.mountpoint_abspath);

-       release_extra_refcnts(&ctx);
-       if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)
+       free_blob_descriptor(ctx.metadata_resource);
+       if (ctx.staging_dir_name)

                delete_staging_dir(&ctx);
                delete_staging_dir(&ctx);

-out_unlock:

        unlock_wim_for_append(wim);
        return ret;
 }
        unlock_wim_for_append(wim);
        return ret;
 }